Medical Plastics News November-December 2012

MPN
MEDICAL PLASTICS NEWS

M I C R O M AT T E R
Pushing Moulding Boundaries with Accumold

ALSO IN THIS ISSUE:
Bioresorbable polymers ISSUE 9
Plastic electronics November/December 2012
Drug contact plastics at Pharmapack WWW.MPNMAGAZINE.COM

MPN All Medical, All Plastics

Contents
5. Editor’s Letter: A thousand miles 26. Folio: Liquid silicone
As the MPN journey moves into its thrid A low-viscosity, addition-curing silicone
year, I take a look back at the steps that for soft compression effects.
brought us to where we are today,
including the most recent Compamed 29. Country Report: Germany
Editor’s Letter—page 5
and Medica shows in November 2012. Germany is the European leader in
innovation—second only to the USA in
6. On the Pulse: Proposed regulation terms of patent registrations. The report
The key changes in the 194-page is followed by a round up of medical
European medical device regulation plastics research institutions in Germany.
proposal are outlined. Also, news of the
devices and diagnostics ally MedTech 34. Cover Story: Micro matter
Europe. Pushing micro moulding boundaries with
Accumold.
11. The SPE: Supercritical CO2
Plastic Electronics—page 14-16 Supercritical gases are being used as 37. Design 4 Life: Licensed to Cure
plasticisers, to improve processing of Dassault launches dedicated medical
viscous high molecular weight polymers, device design sofware.
Bioresorbable Polymers—page 18-25
and for injection moulding of foams.
38. Modular Cleanrooms: A guide
14. Plastic Electronics: Smart switch Sean Fryers of Connect2Cleanrooms
A report from Engel about moulding gives us a glimpse into the versatile
wipe-clean capacitive electronic switches world of modular cleanroms.
by overmoulding film-based printed
electronics. Also, news that resorbable 41. Doctor’s Note: Plastic and 3D Tomo
electronics are a reality. Machined plastics help physicists test
performance of 3D digital breast
18. Materials: Bioresorbable polymers tomosynthesis imaging equipment.
Folio—page 26 US patent applications referencing
resorbables have grown by 37% a year 42. Pharmapack: Drug contact plastic
in 2005-11. Sam Anson investigates why. Interview with Steve Duckworth, head of
The article covers compounding, medical and pharma at Clariant, about
mechanical properties and degradation additives for cyclic olefins, extractables
times, moulding and extrusion, additive and leachables by Joy Harrison of
manufacturing of resorbable tissue Smithers Rapra, and “out of the box”
engineering scaffolds, Absorb—the first packaging design from Team Consulting.
resorbable stent, Purac glass fibre
composites, supercritical CO2 50. Events: Diary and VinylTec
sterilisation, and coloration. Medical plastics diary in Q1 2013 and a
review of SPE’s VinylTec conference in
Chicago by Jodie Laughlin.

Online and in digital
Medical Plastics News is available online, at www.mpnmagazine.com, and
Pharmapack Preview—page 42-49 in digital (on the iPad, mobile phones and computers).

NOVEMBER/DECEMBER 2012 / MPN /3

MPN | EDITOR’S LETTER MPN | CREDITS

editor | sam anson

advertising | gareth pickering

art | sam hamlyn
A journey of a thousand miles Illustrating our achievements so far,
begins with a single step. This phrase by Jesper Laursen of Danish compounder production | adrian price
Chinese philosopher Lao Tzu, who died Melitek, said to me this month: “I saw
in 531 BC and was a contemporary of your article about DEHP and wanted to
Confucius, sums up very nicely where commend you on the result. You pulled subscriptions | tracey nicholls
things have come in the last 18 months together information from a lot of
at Medical Plastics News. interest groups which had the potential publisher | duncan wood
The first step on the Medical Plastics to get very complicated. You reported
News magazine journey was taken two the issues accurately, independently
years ago—in November 2010—when and carefully and this demonstrated
I flew to Düsseldorf to visit the Medica your professional skills. You have shown
and Compamed shows for the first that you are a proper journalist and
time. The trip was booked after I had MPN is a proper magazine.” Medical Plastics News is available on free
presented to my publisher the original Chris James of Monaco-based subscription to readers qualifying under
idea for a magazine dedicated to medical plastics company Promepla also the publisher’s terms of control. Those
medical applications for plastics. congratulated me. He said: “MPN fills a outside the criteria may subscribe at the
I headed there with the goal of gap in the industry for plastic following annual rates: UK: £80
making as many contacts as possible at manufacturers. It is highly relevant, the Europe and rest of the world: £115
companies involved in the use of content is well researched and
plastics for medical applications. I was insightfully written. Sam—your
pleased to find that the show was a knowledge of medical is impressive.”
Medical Plastics News is published by:
hotbed of advanced medical plastic Lao Tzu’s philosophy is helpful
Plastics Multimedia Communications Ltd,
technologies. because it encourages people to achieve
Unit 2, Chowley Court,
By the time I arrived at Compamed things that they would otherwise deem
Chowley Oak Lane,
the following year, our thousand-mile impossible. By breaking things down into
Tattenhall, CH3 9GA
journey had well and truly begun. In the small parts, a task of a size or complexity
T: +44(0)1829 770037
preceeding twelve months, together too great to tangibly conceive instantly
F: +44(0)1829 770047
with my colleague Gareth Pickering, I becomes achievable. And this is a useful
had developed and published three outlook on other aspects of work, as well
issues of a new medical device maga- as life in general.
zine concept covering the medical © 2012 Plastics Multimedia
<< At Compamed 2012, Friedrich Communications Ltd
plastics supply chain. The model enc- Echterdiek from moulder Spang &
ompasses resin supply and pricing, While every attempt has been
Brands shone a light on cost saving for made to ensure that the information
design and materials selection, machin- bag manufacturers, like investing in
ery and auxiliaries, processing methods contained within this publication is
tooling for a twin shot cap design, accurate the publisher accepts no
including moulding and extrusion, end reducing assembly steps and
of line technology, regulation as well as liability for information published in
simplifying manufacturing. Image error, or for views expressed. All
product focuses and clinician reviews. courtesy of PR Portfolio. >>
A year on and I have just returned rights for Medical Plastics News are
from my third Compamed and Med- reserved. Reproduction in whole or
ica event in a row. Being familiar with in part without prior written
the layout of the halls at Messe Düss- permission from the publisher is
eldorf certainly helps make the most strictly prohibited.
of the short time available at the
event. But representing what is now a
recognisable brand in MPN is a big BPA Worldwide
plus when lining up interviews with Membership
important industry representatives.
Furthermore, our pledge of editorial ISSN No: 2047 - 4741 (Print)
independence and technical accuracy 2047 - 475X (Digital)
has clearly built a firm foundation of
trust and reassurance in the industry.

INDUSTRY NEWS | Medical Device Regulation

Europe’s Proposed Medical Device Regulation
WORDS | SAM ANSON

On September 26, 2012, the implementation of existing rules from one administration of the regulation and the
European Commission issued a proposal member state to another as evidenced by scrutiny procedure related to high risk
to overhaul regulations for medical recent reports by UK newspaper The class III implantable devices (see later).
devices and active implantables. The Telegraph. It is also directed towards
proposal document is 194 pages long addressing the problem related to post-
Economic Operators
and is a more stringent approach to market surveillance, highlighted recently by
With a view to achieving better
device regulation. It aims to bring about a the PIP silicone implants scandal, whereby
transparency and traceability, Chapter II
transparent and traceable supply chain competent authorities do not have sufficient
sets out requirements for economic
focusing on the life cycle of a broader mechanisms to monitor information and
operators—manufacturers, authorised
range of products. implement market surveillance. representatives, distributors and
If implemented, being a regulation importers. The responsibilities of all
Definitions
rather than a directive, it will be applied “as economic operators are defined.
is”, bringing consistency across EU states. There are more definitions in the Manufacturers and authorised
The terms of the regulation itself areproposal document than the MDD—50 representatives must have an approved
subject to change following discussion and compared with 14. The definition of a qualified person appointed who is an
approval by the European Parliament. medical device has been expanded to expert in the field with qualifications.
Once the final wording of the include aesthetic implantable devices (for There are also requirements placed on
regulation is published it will enter into example cosmetic breast implants or non- the manufacturer with respect to
force 20 days later and come into full corrective contact lenses) and invasive quantity-structure-property relationships
devices used in humans with associated
effect three years after that. Therefore, it (QSPRs), technical documentation, quality
is likely to be at least 2017 before examples. management systems, post-market
manufacturers are required to comply. surveillance plans and clinical follow ups
Medical Device Coordination Group and labelling languages.
Weaknesses of the MDD The proposed regulation would involve As far as distributors and importers are
The new proposal aims to correct the establishment of an expert committee concerned, imported devices must bear
weaknesses in the current Medical Device called the Medical Device Coordination the importer’s name on the device or its
Directive (MDD). The biggest change Group, made up of members from EU packaging. There are requirements that
concerns the oversight of notified bodies— states and chaired by the EC. The group importers must carry out sampling of
which has led to inconsistency of will be responsible for marketed products while monitoring

Former surgeon and Eucomed chairman October 9, “There has also been
Dr Guy Lebeau (pictured) said: “I urge 2012 North heightened focus on
all decision makers who want to make American Sales engineered polymers
fundamental changes to the European such as co-polyether- October 10,
system for medical devices to tread with
of Medical
ester elastomers 2012
caution. I fully agree that changes need Plastics to (COPE), polyether
October 1, 2012 to be made to the current regulatory Grow by block amides (PEBA),
Eucomed and
EC Publishes framework but let’s make sure we keep 5.2 per cent a and acetal chemistries EDMA Launch
Proposed medical the best system for patients and medical
Year to 2018 that have more MedTech Europe,
progress in Europe.” advanced performance a New Allied
device Regulation
properties for niche,
Devices and
technologically
October 8, 2012 advanced healthcare Diagnostics
Abbott Launches applications, such as Association
tissue engineering and
First Ever Fully
implants,” said research
Resorbable analyst Tridisha
Vascular Stent Goswami. “These new
“Abbott has remained committed to meeting the growing physician and patient materials will expand
demand for a bioresorbable vascular scaffold—from the initial device the scope of plastic
developed nearly 10 years ago to the expansion of our manufacturing polymers' application
capabilities to support this international launch,” said John M Capek, executive and propel the
vice president, Medical Devices, Abbott. market.”

6/ MPN / NOVEMBER/DECEMBER 2012

ON THE PULSE
complaints. Furthermore, these entities Notified Bodies Eudamed database registration is
must declare that they have complied with Perhaps the greatest proposed itemised. The process for a post-market
the requirements of the relevant clauses in change to the regulatory system surr- clinical follow-up is also explained.
the proposed regulation document. ounds notified bodies and their
metamorphosis from an industry partner Market Surveillance and Serious
Additional Device Types into what Emergo describes as “a police- Incidents
New devices to be included and like extension of the authorities’ market Under the proposal, manufacturers are
specifically defined are: devices surveillance apparatus”. required to report a serious incident within
incorporating medicinal product and Existing notified bodies will be subject 15 days. The EU database will be used to
devices composed of substances or a to annual monitoring by authorities and share these reports to relevant bodies.
combination of substances intended to an assessment once every three years by
be ingested, inhaled or administered a joint assessment team. There are also Industry Response
rectally or vaginally; devices incorporating new minimum requirements for notified In general, the proposal has been
materials of biological origin; and bodies, set out in annex VI. welcomed by the industry. However, there
software in devices and standalone The proposal also sets out terms for have been concerns that the proposed
software. the so-called scrutiny procedure—how a scrutiny procedure for high risk class III
notified body should notify the Medical devices is too tough and could stifle
Eudamed Medical Device Database Device Coordination Group about new technological development and delay
and Unique Device Identifiers (UDIs) implantable class III devices, including the device uptake—a key competitive edge of
Chapter III proposes a process by which presentation of a Summary of Safety and Europe’s medical device industry at present.
devices can be tracked within the EU. It Clinical Performance document created At the same time though, other
consists of a newly established medical by the manufacturer. When explaining commentators have suggested that the
device database—known as Eudamed— this requirement, Emergo pointed out proposal should be taken with a degree
with a mandatory requirement on notified that many manufacturers may not have of political context. The Eucamed
bodies, economic operators and member completed this document at this stage. database will require an increase in spend
states to input data. A key component of Overall, the proposed legislation over by the European parliament and medical
the system is the unique device identifier notified bodies is expected to be costly. devices may not be outside the current
(UDI), a set of data which must be compiled climate of austerity for many member
and submitted for every device sold in the Clinical Evaluation and Investigation states. Getting the funding for the
EU market. It is proposed that class III As was generally expected, the roles proposal through parliament may not be
devices will be separated out and subject to of clinical evaluation and investigation are as easy as many people think.
a separate scrutiny procedure and, as part more prominent in the proposed
of the data submitted, a summary of safety regulation than in the MDD. There are Credits: The above article was compiled using
and clinical performance must be included. requirements quoting specific ISO information from medical device regulation
consultants Emergo Group and Meddiquest.
standards and guidance documents and

“The [MedTech Europe] October 24, PREVIOUSLY ON MPNMAGAZINE.COM
alliance not only signifies a
2012 ABHI

12:12:2012
stronger and more
consistent representation of Admits Notified
Europe’s medical technology Bodies
industry, but also provides October 23, 2012 Problem
healthcare stakeholders with October 31, “The PVCMed Alliance will actively
Polycarbonate Following
one unified industry 2012 European communicate about PVC and its
Producers Condemn Telegraph additives, its properties and its
discussion partner when Medical PVC
needed. Being able to speak French Proposed Ban Undercover essential contribution to quality
Industry care delivery for healthcare
with one organisation about of Bisphenol A Report
medtech issues should make
Forms PVCMed professionals. It will also promote
The European Information David Jones, director of
the lives of healthcare Alliance innovative and environmentally
Centre on Bisphenol A, a Communications at ABHI,
players easier and makes friendly practices in PVC healthcare
sub division of European said: “The Daily
industry representation applications”, explains PVCMed
plastics industry Telegraph’s investigation
more credible and Alliance spokesperson Brigitte Dero.
association PlasticsEurope, into Notified Bodies (NBs)
impactful,” said Serge comprises representatives highlights an issue that

24
Bernasconi, chief executive from the main ABHI has raised with
officer of Eucomed, the polycarbonate producers authorities on a number of
European Diagnostics in Europe—Bayer occasions. The control of
Manufacturing Association MaterialScience, Dow, NBs across Europe has not
(EDMA) and MedTech Sabic, Styron and been rigorous enough and
Europe. Momentive. this must be improved.”


ON THE PULSE

INDUSTRY NEWS | Devices and Diagnostics Industries Ally

www.reforminghealthcare.eu website. The new report on
Allied Medical Devices and value-based innovation focuses on how Europe's medical
technology industry is delivering on a promise of a
Diagnostics Industry Group “Contract for a Healthy Future”. The updated industry
strategy document, entitled Industry Strategy, Contract
MedTech Europe for a Healthy Future, details the role of Europe’s medical
technology industry in steering healthcare systems onto a
WORDS | SAM ANSON
sustainable path. Together with a third report by the
Economist Intelligence Unit on Future-proofing Western
On October 10, 2012, the The alliance will be
Europe’s Healthcare, these reports are available as a free
associations representing legally established by
download on the reforminghealthcare.eu website.
the European manufacturing the end of 2012 and
The board of Medtech Europe will comprise three
will collaborate closely
industries for medical representatives from EDMA and three representatives
on common policy
devices, Eucomed, and from Eucomed. The chairmanship will rotate between its
interest areas. All
diagnostic devices, the members. The board will decide future topics of
European medtech
collaboration.
European Diagnostics associations are invited
Announced as a European Industry Alliance in January
Manufacturers Association to join.
2012, MedTech Europe will work alongside its founding
(EDMA), announced that Initially, MedTech
members and will remain a separate entity, as will EDMA
they had formed MedTech Europe’s focus will be
and Eucomed. Medtech Europe is not an umbrella
divided into five
Europe, a new alliance association on top of Eucomed and EDMA.
parts—legislative
intended to encourage The three associations will be helmed by one chief
frameworks for medical
collaboration between the executive officer—Serge Bernasconi. Mr Bernasconi
devices and in vitro
succeeded the previous chief executive of Eucomed,
two industries. The diagnostic (IVD)
Luciano Cattani, and director general of EDMA Volker
announcement was made at products; the European
Oeding on July 16, 2012.
the European MedTech medical technology
Forum in Brussels, Belgium. industry’s five-year
strategy; health << Serge Bernasconi is the
technology assessment; patients and safety; and chief executive officer of
environmental issues. the newly formed allied
Medtech Europe has made a strong start to its role as Medtech Europe as well as
an ally between the medical device and diagnostics Eucomed and the European
manufacturing industries. It has published a new report on Diagnostics Manufacturers
value-based innovation, updated an industry strategy Association (EMDA). >>
document and overhauled the

Reproduced with kind
The Purpose of a Diagnostic Test permission of Eucomed.

by Lluís Bohígas Santasusagna, director, institutional relations, Roche Diagnostics

In vitro diagnostic (IVD) tests are being created for Screening consists of studying patients who do not yet
home use, empowering patients with information about present any signs or symptoms of a specific illness in order
their health and giving doctors the tools to optimise to find out if it has begun to quietly develop and if so, to
treatments. be able to apply treatment as soon as possible. These tests
Diagnosis is the process of finding out if a patient has are applied to large segments of the population and
a specific disease. A medical professional prescribes a test should therefore be simple and cheap.
to make a diagnosis or to exclude possible illness. The Prognosis allows clinicians to assess the likelihood a
results are used to implement treatment or carry out patient has for developing a disease in the future and
further tests. therefore take precautions earlier rather than later. Genetic
Monitoring intends to see if the disease is controlled, tests, for example, analyse a patient’s predisposition for
a purpose that is very common in chronic diseases such as developing a disease, allowing the patient and doctor to
diabetes. Symptoms can be managed with medication, be more attentive to discovering early signs of the disease
hormones or lifestyle changes. and to take preventive measures as needed.


ON THE PULSE

Industry News from the SPE | Supercritical Fluids in Medical Plastics

Supercritical CO2 in BY DR SEAN LYONS,
SENIOR SCIENTIST AT
Medical Plastic Processing BAUSCH + LOMB, IRELAND

The use of supercritical CO2 as a solvent in the CO2. Biomaterials as well as polyethylene and polystyrene
processing of various biodegradable and biocompatible blends have exhibited similar behaviour.
polymers for pharmaceutical and medical applications in
the forms of particles and microcellular foam has Plasticisation
garnered much attention in the last decade. A The use of supercritical fluids in the processing of
supercritical fluid is defined as a substance for which both polymer melts can also lead to changes in the mechanical
pressure and temperature are above the critical values. properties of the materials. Most mechanical property
These fluids possess physicochemical properties— changes during processing can be attributed to the
properties which are both physical and chemical—such as plasticisation of the polymer by the supercritical fluid and
density, viscosity and diffusivity. Density, viscosity and the resultant drop in Tg. Some blended polymer materials
diffusivity are intermediate between those of liquids and have shown significant increases in modulus and strength
gases and are continuously adjustable from gas to liquid when formed in a supercritical fluid assisted process, this is
with small pressure and temperature variations. Both the often due to the tuning of the morphology and degree of
capability of supercritical fluids to replace toxic solvents crystallisation of the material by the supercritical fluid.
and the ability of tuning solvent characteristics for highly Changes in the elastic and creep modulii of materials when
specific separations or reactions have led to the current processed with supercritical fluids can occur in a range of
scientific and industrial interest in supercritical fluids. A materials. However these changes and their magnitude are
supercritical fluid has the unique ability to diffuse through dependent on the solubility of the polymer(s) in the
solids like a gas, and dissolve materials like a liquid. CO2 is supercritical media and the supercritical material’s ability to
a promising alternative to noxious organic solvents and induce crystallisation in the system in question.
chlorofluorocarbons. It has shown versatility as a
supercritical fluid in the synthesis as well as processing of Supercritical Fluids in Fibre Composites
polymers owing to its attractive physical properties. It is Polymer composites processing can also utilise
non-toxic, non-flammable, chemically inert and supercritical fluid technology and extensive research has
inexpensive. Its supercritical conditions are easily attained taken place in this area recently due to the burgeoning use
(Tc = 304.15 K, Pc = 7.38MPa) and it can be removed of these materials in the electronic and medical industries.
from a system by simple depressurisation. Companies such as Ireland’s SCF Processing have been
pioneering research into bespoke industrial polymer
A Processing Aid for Viscous High Molecular Weight processing solutions working with manufacturers to
Polymers provide tailored materials processing transfer services.
The processing of polymers is highly influenced by the Supercritical fluid can be used to carry the monomer onto
viscosity of the bulk materials. Raising the processing the fibres or particles to be used in the composite and to
temperature or the addition of volatile or harmful act as a plasticiser for the synthesised polymer matrix when
plasticisers are often seen as solutions in overcoming the the composite is formed by in situ polymerisation of the
inherent difficulties encountered when processing high monomer. Polymer composites can also be prepared by
molecular weight polymers. However, higher temperatures blending the polymer and the other component in the
during processing can lead to thermal degradation. Also, presence of supercritical media.
added plasticisers remain in the product and thus alter its
properties and performance. The low thermal stability of Microcellular Foam Products
high molecular weight biodegradable polymers has led to The moulding of microcellular foam products, like many
the emergence of supercritical CO2 as a useful processing supercritical CO2 processes, entails the formation of a single
aid. There are many examples of the use of pressurised phase solution. On venting the CO2 by depressurisation,
gases to lower the melt viscosity of numerous amorphous thermodynamic instability causes supersaturation of the CO2
and semicrystalline polymers. Polyethylene glycol, dissolved in the polymer matrix and hence nucleation of
polystyrene and polydimethylsiloxane are examples of cells occurs. The growth of the cells continues until a
polymers where a viscosity reduction has been significant amount of CO2 escapes, the polymer passes
demonstrated upon the incorporation of supercritical
Continued on page 13


Continued from page 11 ON THE PULSE

through its Tg and the foamed structure 50%, reduced scrap rates, and lower Organisations Collaborate
is frozen in place. An added advantage energy consumption (energy savings
of this technology is that due to the are based on reduced processing
on PVC in Healthcare
lower pressures and softer fills, delicate temperatures and are process A new European association,
items can be overmoulded without dependent); lower capital costs the PVCMed Alliance, has been
much of the traditional displacement through the purchase of smaller and launched to promote the use and
and resultant need for excessive control fewer machines, and fewer and less value of PVC in healthcare
features. USA-based Trexel’s MuCell expensive moulds; reduced material applications. PVCMed is an
process technology is said to have been costs through component density alliance of the PVC medical
the first to widely offer microcellular reduction, thinner design, and material industry chain represented by
foaming for both extrusion and injection substitution; and the ability to mould PVC resin and plasticiser
moulding processes and as a result its thermoplastic parts that have a producers and PVC converters.
technology is often licensed to substantially higher dimensional stability
The alliance’s aim is to provide a
industrial partners. Optifoam licensed which are free of warpage.
focal point for communication with
by Switzerland’s Sulzer Chemtech is an The use of supercritical fluids in the
healthcare professionals and
example whereby the supercritical fluid medical device sector affords the
regulators about PVC-based
dosing element is the nozzle of the opportunity to add a new and exciting
healthcare applications, and their
machine as opposed to the barrel. dimension to the processing of
fundamental role in quality of
Another example is Ergocell, the polymeric materials. Examples of
healthcare, safety and cost-
injection moulding process operated medical devices currently being
efficiency, all whilst being
by Japan’s Sumitomo (SHI) Demag for produced commercially using this
environmentally responsible.
the production of microcellular foamed technology include endoscopes, heart
Through an interactive platform,
products. The cycle sequences in the pumps, inhalers and nebulisers. The use
Ergocell process essentially correspond of supercritical CO2 as an inexpensive the alliance seeks to consolidate a
to the sequences in the standard solvent in many polymer processing strong dialogue with all involved
injection moulding process. The applications has already brought many stakeholders to continue
decisive difference is in the gas benefits to the industrial sector. As improving healthcare delivery
delivery, which takes place usage becomes more widespread, together.
simultaneously to plasticising. As the materials that had previously been “The PVCMed Alliance will
screw draws in, melts and delivers designated as ‘un-processable’ due to actively communicate about PVC
material into the space in front of the their high viscosity or their thermal and its additives, its properties and
screw and—in the process—is being instability can now be reinvestigated its essential contribution to quality
pushed back against the back pressure, with the aid of supercritical fluids. care delivery for healthcare
gas is fed into the melt from a gas Supercritical fluid technology has not professionals. It will also promote
metering station. Thus, the screw moves yet reached its potential within industry. innovative and environmentally
back at a speed that is a function of the However, considerable research into friendly practices in PVC
plasticising capacity of the screw. this field is ongoing which would healthcare applications”, explains
Simultaneously, an amount of gas as indicate that the number of applications PVCMed Alliance spokesperson
preset by the operator is delivered and the usage of this technology are Brigitte Dero. Ms Dero adds: “The
into the melt. In contrast to the MuCell only likely to grow. Supercritical CO2 is quality and safety of PVC-based
technology, which requires a modified also examined as a sterilant of healthcare applications guarantee
screw assembly, the injection of the bioresorbable devices on pages 22-25. efficient and widely affordable
supercritical fluid into a module Medical Plastics News would like healthcare systems to continuously
downstream of a conventional to thank Austin Coffey of the Society improve and save patients’ lives.”
plasticisation unit in the Ergocell of Plastics Engineers European At the time of going to press,
technology means that it can be easily Medical Polymers Division for his help members of the PVCMed Alliance
removed, allowing the injection with this article. include BASF, Colorite Europe,
moulding equipment to be used in a Eastman, the European Council of
conventional process when required. Vinyl Manufacturers (ECVM),
OXEA, Renolit and Tarkett.
Advantages of Supercritical Gas
Assisted Injection Moulding
The primary advantages of
supercritical gas assisted injection
moulding are: reduced operating costs
through cycle time reductions of up to


Electronics in Plastic Devices | Smart Plastics

At the Touch of a Button:
Wipe-Clean Moulded Switches for Medical Engineering
For electronic medical devices, control Some people have earmarked smart plastics as a
components such as switches and buttons converging technology where capacitive electronics have
been combined with injection moulding. Others have
must not only be easy to operate—they described them as a new type of composite technology.
must also be easy to clean. They are Fundamentally, they consist of a plastic part moulded
notorious for attracting germs and dirt over a film which has had electronic components printed
particles, particularly in and around the onto it (see image below left). The result is an aesthetically
pleasing part with smooth lines and a clean shiny finish.
tiny crevices and gaps between the The part has electronically interactive parts built in to it to
various components and connections. The form switches and buttons.
development of smart plastics—moulded The electronics components consist of capacitive
components with capacitive electronic sensors which utilise the principle of electrical capacity—
the reciprocation between two spatial points (as in the
functionality—offers device electric force field between two electrodes). The electric
manufacturers the opportunity to flux lines within an electric field may be changed by
develop wipe-clean electronic buttons introducing a conductive object (such as a fingertip). The
and switches while improving production capacitive sensors pick up these changes and respond
with a voltage variation that can be used to initiate a
efficiency and achieving better and more particular function—such as an on/off or up/down
complex designs. command. Since the field lines penetrate non-conductive
solid bodies, the sensor effect also works from a distance
through a thin surface layer such as a thermoplastic or an
operator's gloves.
<< Below: Sensors and conducting paths
are printed onto the film; the
malleability of the film gives product
designers ample scope. >>

<< Above: Smart plastics represent
new opportunities for the medical
engineering sector, especially in the
design of operator control units. >>


PLASTIC
ELECTRONICS

The films can be configured in three dimensions and no assembly is required, productivity is also increased
cut before being overmoulded or back-injected with sharply.
thermoplastic. In this way, capacitive electronics can
replace mechanical switches, buttons and control knobs. Pushing the Boundaries of Product Design
The operating elements are covered by a continuous, Ample scope for design through injection moulding is
even and highly resistant interface. a real benefit here. The flexible print production for the
films makes it possible to position sensors almost
Smart Plastics in Cars anywhere; films can also be formed into virtually any
According to Austrian injection moulding machine shape. Sensitive surface technology is therefore the ideal
manufacturer Engel, smart plastics have undergone most means by which to develop operator control units cost
development in the automotive sector. Michael Fischer effectively—units that Engel say are unbeatable in terms
(pictured right overleaf), sales manager (technologies) of usability and ergonomics.
believes: “The cars of the future will be easier to operate
than smartphones, simply by touch, feel and interaction.”
At its open house in June 2012, Engel presented its
first close-to-production application for smart plastics (see
image). Centre consoles for cars with a sensitive interface
were manufactured using an Engel duo 350 injection
moulding machine with reversing plate and combination
mould. A capacitive, three-dimensional pre-formed film
was placed into the mould by a robot and overmoulded
with PC/ABS. The component was then flow-coated with
polyurethane to protect the surface and produce a high
quality impression.

<< Injection moulding covers the electronic elements with
a continuous and highly resistant plastic interface. >>

Of course, ergonomics and cost-effectiveness have
been key considerations in other sectors of industry for
many years. With this in mind, a design study for the
control panel of a washing machine was recently
presented. Meanwhile, Engel and its partners are starting
to field enquiries from the medical engineering sector.
“I think the fact that this technology addresses a whole
set of requirements at a stroke represents a major
<< The manufacturing cell for centre consoles with capacitive opportunity for medical engineering”, says Christoph
electronics delivers outstanding cost effectiveness. A high Lhota (pictured middle overleaf), the head of Engel's
level of automation—and the sensitive surface technology medical business unit. “Firstly we're doing more to
itself—are critical factors. >> address stringent hygiene requirements, secondly we're
improving the ergonomics of medical engineering
The technology will now be marketed under the name products and thirdly we're drastically cutting production
Sensitive Surface by Engel and its project partners. “We costs. Pressure on costs is rising in the medical
are in discussion with various automobile companies and engineering sector too.”
OEMs with a view to mass-producing the first sensitive At present, lessons learned from the automobile
surface applications in three to four years”, reveals Fischer. industry are being developed and applied to the medical
In the case of vehicle construction, the hygiene engineering field. Alongside Engel, a company heavily
aspects of a continuously sealed interface are less involved in the specialist development and production of
important than ease of use and high efficiency in the intelligent, multi-layered interfaces is Austria-
manufacturing process. Whereas conventional headquartered smart plastics technology developer
manufacturing often involves the individual production plastic electronic. One key development issue at present is
and assembly of more than 100 small parts, capacitive the sterilisability of intelligent electronic components. “We
films and plastic granulate facilitate the production of successfully carried out function tests for the automobile
functional, ready-to-install components in a single work industry in the temperature range of -40°C to +85°C”,
step. “Taking the centre consoles as an example, reports Philipp Weissel (pictured left overleaf), CEO of
production costs are reduced by at least 30% if we look
at the whole process”, emphasises Michael Fischer. Since Continued on page 16


PLASTIC
ELECTRONICS

Electronics in Plastic Devices | Smart Plastics

Continued from page 15

plastic electronic. “We're now working on raising the Bioresorbable Electronic
temperature range for critical applications in medical
engineering.” Devices a Reality
Upper Austria Hailed as Epicentre of Smart Plastics It’s not often that a doctor can claim two game-
Evolution changing inventions in less than a year. That’s what Dr
As far as the future research activity of Engel and Marvin J Slepian can boast, having developed a new class
plastic electronic is concerned, Upper Austria promises of small, high performance electronics that are
ideal conditions. Few places elsewhere in the world are biodragradable and capable of dissolving completely in
such a high concentration of companies and research water or bodily fluids following a predefined period of
institutes to be found alongside the infrastructure needed functionality. Earlier this year, Dr Slepian’s company,
for smart plastics. Early in 2011, this density of specialist Syncardia—a US-based medical device manufacturer—
expertise led to the foundation of a smart plastics developed and successfully implanted the first artificial
networking group, the Smart Plastics initiative. The aim of plastic heart. In the 1980s, Dr Slepian developed one of
this group is to accommodate the entire value chain for the first prototypes for biodegradable stents.
intelligent electronic plastic products within Upper Dr Slepian is director of interventional cardiology and
Austria so that world-leading system solutions may be professor of medicine at the USA’s University of Arizona
developed in partnership. To further this goal, Smart (UA) Sarver Heart Center with a joint appointment in the
Plastics is hosting a congress in Linz, Upper Austria—the UA department of biomedical engineering. He is also co-
same place where Engel’s headquarters are—on June founder and chief technical officer of Syncardia.
10-11, 2013. Details of the technology on which this dissolvable
electronic device is based—known as transient
Editor’s Outlook electronics—were published in a September 2012 copy of
Plastic electronics may help designers find an Science, a leading US scientific journal.
alternative to conventional membrane keyboards in The paper describes a number of examples of transient
medical situations. These membranes attempt to integrate electronic devices, including a system designed to monitor
a continuous seal over an interface, but are said to be less and prevent bacterial infection at surgical incisions which
than robust in practice and constitute a source of has been successfully demonstrated in rats. The paper was
infection in sterile environments like operating theatres. written by Fiorenzo Omenetto, professor of biomedical
Thanks to the commitment in Austria for smart plastics engineering at the Tufts School of Engineering in
and Engel’s lead in the moulding expertise, observers can Massachusetts. Omnetto worked with researchers at
expect product designers to turn to smart plastics for University of Arizona and Northwestern University in
improved functionality, aesthetic design, not to mention Illinois. Materials found in conventional integrated circuits
the wow factor of a highly sensitive button which requires are used—silicon and magnesium—but in an ultrathin form
absolutely no pressure to activate. It takes the phrase “at that is then encapsulated in silk protein, which is
the touch of a button” to a whole new level. dissolvable. Device dissolution is
reportedly further
controlled by sheets of
silk protein in which the
electronics are supported
and encapsulated.
Omenetto and his team
have discovered how to
adjust the properties of
silk so that a wide range
of degradation times can
<< Left to right: Michael Fischer, Engel sales be predetermined.
manager (technologies), Christoph Lhota,
Engel’s head of medical, and Philipp Weissel, Photo Source:
CEO of plastic electronic. >> Beckman Institute, University of
Illinois and Tufts University.


Material Diagnosis | Growing Popularity of Bioresorbable Polymers

Bioresorbable Polymers:
Patents Growing by 37% a year
WORDS | SAM ANSON

Bioresorbable polymers are nothing new. They trimethylene carbonate to form poly(glycolide-co-
have been used in dissolvable sutures for a trimethylene carbonate), or (PGA-co-TMC). PGA
degrades to form glycolic acid.
number of years. But according to the United
States Patent and Trademark Office database, Compounding, Mechanical Properties and
the number of patents referencing Degradation Times
bioresorbable and medical grew from 48 in The mechanical properties and degradation time of a
bioresorbable device can be tailored to a specific
2005 to 311 in 2011, an average annual growth application by adjusting the molecular weight, crystallinity
rate of 37%, or 548% in absolute terms. In the and hydrophilicity of the polymer. This is achieved by
last two months, the first fully resorbable drug varying the percentage of polylactide D or L forms, and
eluting stent was CE marked for sale in Europe. polyglycolide. Tony Listro, managing director of specialist
US medical polymer compounder Foster Delivery Science
Here Sam Anson looks at bioresorbable explains: “Compositions with higher hydrophilic and
processing considerations while reviewing amorphous structures and a lower molecular weight
examples of application success. resorb faster, yet often sacrifice mechanical strength.
Conversely, higher crystallinity and molecular weight
improve mechanical properties and decrease resorption
Bioresorbable polymers, also referred to as
rates.”
bioresorbable or degradable polymers, are polymer
Bone growth additives, such as tricalcium phosphate
materials which can be safely absorbed by the body so
(TCP) or hydroxyapetite acid (HA) can be melt blended
that the materials from which a construction is made
into these polymers to enhance bone growth during
disappear over time.
degradation. Additionally, the low melt temperatures of
The following report examines bioresorbables from
many bioresorbable polymers allows for melt blending
the following perpectives—compounding, mechanical
active pharmaceutical ingredients (APIs) for controlled-
properties and degradation times; moulding and
release drug delivery during degradation. However,
extrusion; degradation testing; additive manufacturing of
higher molecular weight polymers often require higher
resorbable tissue engineering scaffolds; Absorb—the first
melt temperatures and thus limit melt blending of some
ever resorbable stent; Purac glass fibre composites;
APIs with low degradation temperatures.
supercritical CO2 sterilisation; and coloration.
Twin screw extruders optimise bioresorbable polymer
blending, including distribution and dispersion of additives.
Polymer Types
Due to the high cost of bioresorbable polymers, which can
The most common bioresorbable polymer is polylactic
often exceed US$1,000 per lb (US$2,200 per kg) and the
acid (PLA), also known as polylactide, and is made from a
relatively small nature of the implantable applications, small
lactide monomer. Generally speaking, PLA is the main
scale twin screw extruders—between 16 mm and 27 mm—
building block for bioresorbable polymer materials.
are ideal. Since these polymers begin degradation when
Common derivatives of PLA are poly-L-lactide (PLLA),
exposed to moisture, desiccant and vacuum driers are
poly-D-lactide (PDLA) and poly-DL-lactide (PDLLA).
required prior to melt blending. Unlike non-resorbable
When in the body, PLA degrades into lactic acid, a non-
polymers that are often water cooled upon exiting the
toxic chemical which occurs naturally in the body.
extruder in strand form, bioresorbable compounds must
Polyglycolic acid (PGA), or polyglycolide (PG), is
be air cooled. Pelletised strands destined for finished
another type of bioresorbable polymer usually used for
device processing must be thoroughly dried and properly
bioresorbable sutures. The material can be
packaged to prevent exposure to air moisture that can
copolymerised with lactic acid to form to form poly(lactic-
cause premature degradation.
co-glycolic acid), or PLGA, with e-caprolactone to form
poly(glycolide-co-caprolactone), or PGCL, and with


BIORESORBABLE
POLYMERS

Moulding and Extrusion Considerations
The processing of bioresorbable polymers must be Additive Manufacturing of Resorbable Tissue
handled with care. The materials themselves are highly Engineering Scaffolds
hydrophilic, which is to say that they love water and will Additive manufacturing is being used to produce
absorb any moisture with which they come into contact. scaffolds for tissue engineering from bioresorbable
Unless properly dry, the materials will not melt and polymers. A number of years back, researchers from A
recrystallise as expected, making moulding and extrusion Star, a leading Singaporean research institution,
difficult. At the same time, bioresorbable polymers are successfully developed a technology for fabricating
sensitive to heat, and molecular structures can be damaged resorbable polymeric tissue scaffolds with high strength
through exposure to excessive temperatures during drying. and porosity using additive manufacturing. Dr Margam
With this in mind, careful and thorough drying at low Chandrasekaran (Chandra), now CEO and chief scientist
temperatures is needed, while the humidity of the at Singapore-based tissue engineering scaffold
processing environment must be considered. manufacturer Bioscaffold International, was one of the
Knowing the melt and recrystallisation behaviour of lead inventors of the technology. Along with a team of
bioresorbable materials is important, as is understanding clinicians at the National University of Singapore, at A Star
the melt flow viscosity. Often materials will have a low Chandra developed an application of the technology to
melt temperature, a high crystallisation temperature and produce a commerical product for high strength
generally be extremely viscous—like hot honey—except resorbable dental scaffolds using
at a small temperature range between the two. This additive manufacturing.
means that there is a very small temperature range at Chandra explains: “We
which materials can be processed—that is to say, the used a combination of PLGA
range at which the material is molten, at which the with PVA and changed the
viscosity is at the right level for injection moulding or binder used in the 3D
extrusion, and at which the material won’t crystallise printing process to
prematurely. produce parts in a
Due to their delicate molecular structures, desired shape and
bioresorbable polymers are limited in terms of the amount then used a post
of time they can remain molten, so cycle times must be processing technique
kept within this range, which is often not very long. similar to particulate
leaching to strengthen the
Degradation Testing of Bioresorbable Medical structure. In fact, besides
Devices PLGA, we did work on << The 3D–Bioplotter from
On November 28, 2012, the FDA held a public PCL, PLA and PGA. A EnvisionTec is specially designed
workshop on the testing of bioresorbable medical paper was published in to process a large range of
devices at its White Oak campus in Silver Spring, 2007 in the Journal of materials, from hard polymers,
Maryland, USA. Materials Processing and through ceramic pastes to soft
The workshop, entitled Workshop on Absorbable Technology.” hydrogels including cells. >>
Medical Devices: Lessons Learned From Correlations of Today, Chandra’s
Bench Testing and Clinical Performance, was co- company manufactures implantable tissue engineering
sponsored by ASTM (American Society for Testing and scaffolds for dentists made from PLGA. The scaffolds are
Materials) International, a US organisation responsible for used by dentists to preserve tooth sockets following
the development and delivery of international voluntary removal of a tooth. The implant encourages bone growth,
consensus standards for engineered products, including thereby preserving the socket while the gums heal. This
medical devices. means that any further restorative procedures, such as
The purpose of the workshop was to provide a forum dentures or implantable false tooth fittings, are vastly
for highlighting and discussing the use of bioresorbable improved.
materials in medical devices across a broad range of Another resorbable scaffold application,
indications with the aim of defining successful and manufactured in the USA by tissue engineering device
unsuccessful methods to predict clinical performance. pioneer 3D Biotek, is a three dimensional PLGA-based
The main topics discussed included identification of degradable porous cell culture device for medical
test methods for establishing correlations between in research processes. The device is special because its
vitro and in vivo degradation of absorbable implantable three dimensional nature allows cells to grow in three
devices, and the interaction of mechanical loading and dimensions. Its 100% porous nature allows cells to be
mechanical performance with degradation. While there seeded very easily. Because PLGA is biocompatible, the
was an emphasis on cardiovascular indications as part of a scaffolds, with or without cells, can be implanted into
panel session, characterisation techniques and animals. Degradation time is approximately 4-5 months.
experiences from both cardiovascular as well as non- Germany-headquartered 3D printer supplier
cardiovascular devices were discussed and encouraged. Continued on page 20


BIORESORBABLE
POLYMERS

Continued from page 19 the degradation rate govern this performance.
EnvisionTec’s 3D-Bioplotter is an all-purpose direct The potential long term benefits of a scaffold that
manufacturing tissue engineering machine for the dissolves are significant. The vessel may expand and
production of hard and soft scaffolds from biomaterials, contract as needed to increase the flow of blood to the
cells as well as synthetic materials. It is specially designed heart in response to normal activities such as exercising.
to process a large range of materials, from hard polymers, Treatment and diagnostic options are broadened. The
through ceramic pastes to soft hydrogels. need for long-term treatment with anti-clotting
According to EnvisionTec, the 3D-Bioplotter is medications may be reduced. And future interventions
specially designed for work in sterile environments in a would be unobstructed by a permanent implant.
laminar flow box, a requirement of biofabrication, for “This innovation represents a true paradigm shift in
example when using alginate cell suspensions for the how we treat coronary artery disease,” said Patrick W
construction of cell-laden scaffolds. Additionally, the 3D- Serruys, a medical doctor and professor of interventional
Bioplotter can use up to five different tools per job. This cardiology at the Thoraxcentre, Erasmus University
means that scaffolds fabricated using the 3D-Bioplotter Hospital, Rotterdam, the Netherlands. He added: “With
can have up to five different materials, or five different the launch of Absorb, a scaffold that disappears after
types of cells in specific positions. doing its job is no longer a dream, but a reality.”
In contrast to other rapid prototyping techniques the Absorb is now available in a broad size matrix to
3D-Bioplotter, EnvisionTec says, uses a very simple and support the needs of physicians treating patients with
straightforward technology, invented in 1999 at the CAD. There are 7 sizes available—varying in length from
Freiburg Materials Research Centre in Germany. The 12 mm to 28 mm and in diameter from 2.5 mm to
manufacturing process works by air pressure being 3.5 mm. The strut thickness and width are approximately
applied to a liquid and liquefied material, which solidifies 150 μm and 180 μm respectively.
upon dispensing. At the time of going to press, Absorb is neither
The 3D-Bioplotter is delivered together with a PC approved nor authorised for sale and currently is in
workstation which operates and monitors the system. After development with no regulatory status in the United States.
transferring the 3D CAD data to the PC it is processed by
the Bioplotter’s software package. The preprocessed data << The backbone of
is then transferred to the 3D-Bioplotter using a network Absorb, the first
connection. The Bioplotter software monitors the working fully resorsable drug
process until it is completed. eluting stent, is
produced by
Abbot Launches First Ever Bioresorbable Vascular extruding PLLA into
Scaffold a tube and then
USA-headquartered Abbott, one of the world's radially and axially
leading medical device OEMs with 91,000 employees, has expanding that tube
launched Absorb, the first fully resorbable drug eluting in a process which is
vascular scaffold. similar to stretch
Absorb is available for use by clinicians in treating blow moulding. The
coronary artery disease (CAD) across Europe, Asia Pacific tube is then lasered
and Latin America. It works by restoring blood flow to the to produce the
heart—similar to a metallic stent—but instead of being scaffold pattern. >>
permanent it dissolves into the body. After dissolution it
leaves behind a treated vessel that may resume more Bioresorbable Glass Fibre Composites for Load
natural function and movement because it is free of a Bearing
permanent metallic stent. In August 2012, Netherlands-based bioresorbable
In order to create the backbone of the device, PLLA polymer manufacturer and owner of the Purasorb brand
resin is extruded into a tube, then radially and axially of medical resorbable polymers Purac acquired FiberLive,
expanded in a process that resembles stretch blow an advanced resorbable glass fibre composite technology.
moulding. The scaffold pattern is then cut with a laser, and The acquisition included the intellectual property of the
the finished product is coated with a drug and polymer FiberLive technology and its key personnel.
mixture and crimped onto a catheter before being According to Purac, FiberLive is a unique patented
packaged and sterilised. composite consisting of a matrix of resorbable silica-
According to Abbott, PLLA has an intrinsic degradation based glass fibres and resorbable polymers, forming an
rate that is influenced in vivo by very few factors. Device exceptionally strong resorbable composite material—up
performance over its degradation lifecycle is tuned to to six times stronger than cortical bone. This unique
match physiological requirements for vessel support. The composite material widens possibilities to use resorbable
polylactide molecular weight in the finished product and
Continued on page 22


Material Diagnosis | Growing Popularity of Bioresorbable Polymers
Continued from page 20 (PDLLA), polyglycolide (PG), polycaprolactone (PCL)—
and copolymers L-lactide/DL-lactide (PLDL),
materials into the fields of bone fixation, where in the past L-lactide/D-lactide (PLD), L-lactide/glycolide (PLG), L-
it has been impossible due to a lack of load-bearing lactide/captrolactone (PLC) and DL-lactide/glycolide
properties of conventional biopolymers. The material can (PDLG). The company also offers custom synthesis of
be used in different kinds of orthopaedic treatments, bioresorbable polymers.
including craniomaxillofacial (skull and jaw), sports
medicine, trauma and spinal procedures.
When commenting on the acquisition, Menno << Implantable
Lammers, managing director Purac Biomaterials, said: “This resorbable screws
technology will be a game changer in the orthopaedic made from Purac
resorbable market, where load bearing properties are FiberLive. >>
needed. The FiberLive technology is the strongest fully
resorbable material available for human implants, with
strength up to six times higher than cortical bone,
comparable to metal. For decades Purac Biomaterial has
been the leading company in the field of medical Supercritical CO2 Sterilisation of Bioabsorbable
resorbable polymer materials having strong commitment Polymer Devices
and enthusiasm towards innovation and development in A team of researchers at NovaSterilis, a supplier of
the field. With the acquisition of this innovative supercritical carbon dioxide (scCO2) sterilisation
resorbable composite material we are able to further technologies and equipment based in the state of New
widen our capabilities to serve our customers according York, working with Dr Chih-Chang Chu, a professor from
to their requirements.” Cornell University (Ithaca, NY), have developed a novel
The Purasorb brand of resorbable polymers covers a process for sterilising devices made from bioresorbable
broad range of grades, including polymers—poly-L- polymers using scCO2. The technology is being distributed
lactide (PLLA), poly-D-lactide (PDLA), poly-DL-lactide in Europe by European Medical Contract Manufacturer


BIORESORBABLE
POLYMERS

(EMCM) based in Nijmegen, The Netherlands. inactive, which means that when the spore is killed, there
According to a poster presentation from the team is little or no effect on the delicate surrounding material.
displayed at the Ninth World Biomaterials Congress in Sterilisation can be done inhouse as there are low
China in June 2012, which reported the feasibility of capital expenditures required, meaning that device
NovaSterilis’s scCO2 sterilisation method for an manufacturers can retain full control and sight of their
absorbable suture, scCO2 is preferable to ethylene oxide products during sterilisation. Furthermore, the time taken
when sterilising bioresorbable devices for a number of for this method is much shorter than traditional ethylene
reasons, as follows. oxide—according to NovaSterilis president and CEO
Devices can be processed at low pressure and David C Burns, “you are talking minutes to hours rather
temperature, which reduces costs and energy requirements. than hours to days”.
Low temperature processing makes it ideal for specialist Residual chemicals are non existent or negligible
bioresorbable devices due to their highly sensitive following sterilisation. Any that do remain are non-toxic as
molecular structure (as explained earlier). Furthermore, the confirmed by toxicity testing.
CO2 molecule has a low surface tension which also reduces ScCO2 sterilisation is a new technology. The first 510k
the likelihood of damaging delicate molecular structures submission is expected within the next 12 months. Four
commonly found in bioresorbable materials. companies are currently using the technology to sterilise
The fact that scCO2 sterilisation can be used to allograft tissue because of its gentle effect on collagen
sterilise in between the pores of a material—it is said to (biopolymer)—three in the USA and one in Australia.
penetrate deeply into a substance—plays perfectly into According to David C Burns, president and CEO
the hands of bioresorbable polymer devices as by their NovaSterilis: “Today’s highly technical products require
very nature they are very porous. The poster points to very specialised handling, including sterilisation in smaller
the fact that spores can live in the pores of the material batches. Moreover, the desire to maintain custody of
and the method can get right between the microscopic product is more important to many of our customers.”
holes to ensure they are completely sterile. Furthermore, The NovaSterilis scCO2 process is said to be safe for
reinforcing the delicate nature of the method, the scCO2 many polymers, allograft tissues, plastics, and surgical
can penetrate inside the spore and oxidise it to render it Continued on page 25


BIORESORBABLE
POLYMERS

Continued from page 23 as doxycycline antibiotics and cell growth substances.
metals. NovaSterilis manufactures 20-litre and 80-litre fully The process whereby these granules are made is an
automated, computerised, and network capable inhouse developed proprietary process of DS. The
sterilisation units. Designed with a small footprint, these materials start out as soft porous granules of tricalcium
units are ideal for biomedical material companies that phosphate (TCP). Then using a sintering process, the
require high value and flexibility. NovaSterilis provides granules are hardened and coated with PLA before being
supportive technical services, assisting customers to packaged into easy-to-use kits ready for orthopaedic
determine if this process is appropriate for specific surgeons.
products, establishing cycle times and developing Tissue fixation implants are injection moulded
validation and regulatory plans. degradable PLA-based components for fixing tissue in
In 2007 NovaSterilis won the Presidential Green place during surgery. Processed by closely controlling
Chemistry Challenge Award Presented by the US cycle times and temperatures, DS manufactures a range of
Environmental Protection Agency. devices, including cages for spinal applications, knee
interference screws, small pins for foot surgery, implants
<< This is a highly magnified scCO2 for cranioplasty and suture anchors for shoulders. In this
sterilised Dexon suture, area, the company offers full device development and
manufactured by USA- manufacturing services, including design and
headquartered device development, manufacturing, packaging, sterilisation,
manufacturer Covidien. registration as well as development and manufacture of
Note the scale—100 μm— the instruments required for application.
on the left hand side. The
image is courtesy of Dr Coloured Bioresorbables
Chih-Chang Chu of Cornell Visibility of small transparent implantable devices can
University’s Department be difficult intra operatively. Coloured devices can
of Fiber Science and support precision and quality control of the surgeon.
Apparel Design. >> Bioresorbable colours are another product offering of DS.
The company is an expert at integrating FDA approved
Profile of a Bioresorbable Expert: Degradable implantable colours into bioresorbable devices. The issue
Solutions, Switzerland with pigments in implantable devices is that there are very
Degradable Solutions (DS), based in Switzerland, few suppliers of biocompatible colours. DS has secured
manufactures a number of bioresorbable products. The the supply of compliant pigments.
company is a spin-off from the Swiss Federal Institute of
Technology Zurich (Eidgenössische Technische
Hochschule Zürich—ETH) and was taken over in
November 2011 by Swiss oral care device manufacturer
Sunstar Group. It is a technological leader in its field and
has extensive experience of working with bioresorbable
polymers. Two areas of interest are bone graft
<< Degradable Solutions,
substitutes and tissue fixation devices.
based in Switzerland, has
Bone graft substitutes are sold under the brand name
developed granules (left) of
easy-graft and are the company’s most important
resorbable tricalcium
product. Easy-graft consists of resorbable granules of
phosphate coated with PLA.
calcium phosphate which have been coated with
When mixed with an
polylactic acid. The granules are injected into parts of the
activator liquid the granules
body where bone needs to grow, particularly broken
form a sticky putty which can be injected (above) into
bones and teeth. An activator liquid is added to the
the body before setting to form a bioresorbable porous
granules just before injection. The activator causes the
bone cement that allows bone to grow in and around it
polylactic acid coatings to form a sticky putty which allows
as it degrades slowly over time. >>
the granules to be applied directly through a syringe.
When in contact with blood, the biomaterial solidifies << Degradable Solutions is
and forms a defect-analogue, mechanically stable mass of also an expert injection
material which is porous and will be replaced by bone moulder of resorbable
tissue over time. materials. This screw,
This occurs thanks to the fact that the calcium Sysorb, is a patented
phosphate degrades over time, allowing bone cells to
turbine shaped screw head
grow in and around the calcium phosphate granules as
for reconstruction of the
they degrade. DS is also talking about incorporating
cruciate ligament. >>
active pharmaceutical ingredients into the material, such


Medical Plastics News November-December 2012

Medical Plastics News November-December 2012

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