10 de Nov de 2014

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  1. Nanomedicine
  2. Premises • Since the human body is basically an extremely complex system of interacting molecules (i.e., a molecular machine), the technology required to truly understand and repair the body is the molecular machine technology : NANOTECHNOLOGY • A natural consequence of this level of technology will be the ability to analyze and repair the human body as completely and effectively as we can repair any conventional machine today.
  4. NANOTECHNOLOGY Feynman: "There is plenty of room at the bottom" • Seminal speech on December 1959 at CalTech • " Why can’t be compressed 24 volumes of Encyclopedia Britannica on a pin head ?“ • " The biological example of writing information on a small scale has inspired me to think of something that should be possible " • In 1990, IBM scientists wrote the logo IBM using 35 xenon atoms on nickel.
  5. NANO ≈ < 100 nm
  6. Nanomedicine: EC European Technology Platform (ETP)
  7. E.C.-ETP “Nanomedicine, is defined as the application of nanotechnology to achieve breakthroughs in healthcare. It exploits the improved and often novel physical, chemical and biological properties of materials at the nanometer scale. Nanomedicine has the potential to enable early detection and prevention, and to essentially improve diagnosis, treatment and follow-up of diseases. ……………………….
  8. Nanomedicine: European Science Foundation (ESF) “The field of Nanomedicine is the science and technology of diagnosing, treating and preventing disease and traumatic injury, of relieving pain, and of preserving and improving human health, using molecular tools and molecular knowledge of the human body. It embraces sub-disciplines which are in many ways overlapping and are underpinned by common technical issues.”
  9. The numbers of nanomedicine The global nanomedicine market reached $63.8 billion in 2010 and $72.8 billion in 2011. The market is expected to grow to $130.9 billion by 2016 at a compound annual growth rate (CAGR) of 12.5% between years 2011 and 2016.
  10. The “Nanomedicine Market Global Industry Analysis, Size, Share, Growth, Trends and Forecast, 2013 - 2019," predicts that the total nanomedicine market globally will be worth USD 177.60 billion by 2019. The leading application segment in the past years within the nanomedicine market was that of oncology, holding a 38% share of the overall market in 2012, as a vast number of commercially available products prevail in this sector. The development of nanomedicine-based treatments and products that are able to directly target tumors in the brain and other bodily sites is poised to be a significant factor affecting growth in this market.
  11. Though the largest market segment within the nanomedicine market is that of oncology, the fastest growing segment is the cardiovascular market. Growth in this segment has been fuelled by the presence of a sizeable patient population, and a simultaneous growth in the demand for device and drugs that are based on nanomedicine. These factors are collectively anticipated to further fuel the growth of the cardiovascular segment within the nanomedicine market.
  12. Number of publications related to “nanomedicine” in Medline 25000 20000 15000 10000 5000 0 1 2 3 4 5 6 7 8 9 10 1995 1997 1999 2001 2003 2005 2007 2009 2011 2013
  13. 1966
  14. Topics in nanomedicine • Therapy: Drug Delivery: Use nanodevices specifically targeted to cells, to guide delivery of drugs, proteins and genes Drug targeting : Whole body, cellular , subcellular delivery Drug discovery : Novel bioactives and delivery systems
  15. Topics in nanomedicine • Diagnosis: Prevention and Early Detection of diseases: Use nanodevices to detect specific changes in diseased cells and organism.
  16. Nanoparticles (NP): Smart Nanostructures for diagnosis and therapy
  17. Why Nanoparticles 1) Drugs, contrast agents, paramagnetic or radiolabeled probes can be vehiculated by NPs 2) NPs can be multi-functionalized to confer differents features on them
  18. 1) Drugs, contrast agents, paramagnetic or radiolabeled probes can be vehiculated by NPs • Targeting: nanoparticles control the drug delivery. The drug follows the NP • Drugs are concentrated to target. Less systemic toxicity. • Less drug is necessary • Drugs are protected inside NPs and are not degraded. Longer drug halflife (if NP have long halflife). • Biologicals (proteins, genes, Antibodies) are most favourable candidates for NP
  19. 2) NPs can be multi-functionalized to confer differents features on them • Multi-functionalization: Controls drug targeting, drug dosage, and drug release characteristics
  20. An ideal Multi-functional nanoparticle vector Anticorpo Polietilenglicol (PEG) Indirizza la NP verso un antigene specifico sulla cellula da colpire Evita che NP venga digerita nei lisosomi Evita che la NP venga rimossa dal circolo Tat peptide Determina Fusione e ingresso della NP nella cellula Probe magnetico Permette imaging tramite MRI Farmaco
  22. Carbon-based: Buckyballs and Nanotubes C60 1nm
  23. What are Carbon Nanotubes? Carbon nanotubes are hexagonally shaped arrangements of carbon atoms that have been rolled into tubes.
  24. Human hair fragment (the purplish thing) on top of a network of single-walled carbon nanotubes Nanotubes are members of the fullerene structural family, which also includes the spherical buckyballs. Their name is derived from their size, since the diameter of a nanotube is on the order of a few nanometers, while they can be up to tenths of centimeters in length Nanotubes are categorized as single-walled nanotubes (SWNTs) and multi-walled nanotubes (MWNTs)
  25. Single-walled • Most single-walled nanotubes (SWNT) have a diameter of close to 1 nanometer, with a tube length that can be many millions of times longer..
  26. Armchair (n,n) • Single-walled nanotubes are an important variety of carbon nanotube because they exhibit electric properties that are not shared by the multi-walled carbon nanotube (MWNT) variants.One useful application of SWNTs is in the development of the first intramolecular field effect transistors (FET). • (Used for nanobiosensors).
  27. Multi-walled • Multi-walled nanotubes (MWNT) consist of multiple rolled layers (concentric tubes) of graphite. • In the Russian Doll model, sheets of graphite are arranged in concentric cylinders, e.g. a (0,8) single-walled nanotube (SWNT) within a larger (0,10) single-walled nanotube. • In the Parchment model, a single sheet of graphite is rolled in around itself, resembling a scroll of parchment or a rolled newspaper. The interlayer distance in multi-walled nanotubes is close to the distance between graphene layers in graphite, approximately 3.4 Å.
  28. Properties of Carbon Nanotubes Nanotubes have a very broad range of electronic, thermal, and structural properties that change depending on diameter, length. They exhibit extraordinary strength and unique electrical properties, and are efficient conductors of heat.
  29. Strength • Carbon nanotubes are the strongest and stiffest materials yet discovered in terms of tensile strength and elastic modulus respectively. This strength results from the covalent sp2 bonds formed between the individual carbon atoms. In 2000, a multi-walled carbon nanotube was tested to have a tensile strength of 63 gigapascals (GPa). (This, for illustration, translates into the ability to endure tension of a weight equivalent to 6422 kg on a cable with cross-section of 1 mm2.) Since carbon nanotubes have a low density for a solid of 1.3 to 1.4 g·cm−3, its specific strength of up to 48,000 kN·m·kg−1 is the best of known materials, compared to high-carbon steel's 154 kN·m·kg−1.
  30. Electrical properties • Depending how the graphene sheet is rolled up, the nanotube can be metallic; semiconducting or moderate semiconductor.
  31. Thermal property • All nanotubes are expected to be very good thermal conductors along the tube, exhibiting a property known as "ballistic conduction," but good insulators laterally to the tube axis.
  32. Defects • As with any material, the existence of a crystallographic defect affects the material properties. Defects can occur in the form of atomic vacancies. High levels of such defects can lower the tensile strength by up to 85%. Crystallographic defects also affect the tube's electrical properties. A common result is lowered conductivity through the defective region of the tube.
  33. Natural, incidental, and controlled flame environments • Fullerenes and carbon nanotubes are not necessarily products of high-tech laboratories; they are commonly formed in such places as ordinary flames,produced by burning methane,ethylene,and benzene,and they have been found in soot from both indoor and outdoor air. However, these naturally occurring varieties can be highly irregular in size and quality because the environment in which they are produced is often highly uncontrolled.
  34. Potential and current applications of CNT
  35. In electrical circuits • Nanotube based transistors have been made that operate at room temperature and that are capable of digital switching using a single electron.The first nanotube integrated memory circuit was made in 2004. Nanotube Transistor
  36. Proposed as a vessel for transporting drugs into the body. The ends of a nanotube might be capped with a hemisphere of the buckyball structureThe drug can be attached to the side or trailed behind, or the drug can actually be placed inside the nanotube. . Nanotube Nanocap
  37. Covalent Functionalization Non-Covalent Functionalization
  38. Non-covalent funzionalization (DNA)
  39. Toxicity Their final usage, however, may be limited by their potential toxicity. Results of rodent studies show that CNTs produce inflammation, epithelioid granulomas (microscopic nodules), fibrosis, and biochemical/toxicological changes in the lungs. Comparative toxicity studies in which mice were given equal weights of test materials showed that SWCNTs were more toxic than quartz, which is considered a serious occupational health hazard when chronically inhaled. The needle-like fiber shape of CNTs is similar to asbestos fibers. This raises the idea that widespread use of carbon nanotubes may lead to pleural mesothelioma, a cancer of the lungs, or peritoneal mesothelioma (both caused by exposure to asbestos). Available data suggest that under certain conditions, especially those involving chronic exposure, carbon nanotubes can pose a serious risk to human health.
  40. Lipid-based NPs :Liposomes and solid lipid nanoparticles (SLN) 50 – 500 nm 40-1000nm
  41. •LIPOSOMES are the smallest spherical structure technically produced by natural non-toxic phospholipids and cholesterol.
  42. Metal-core nanoparticles
  43. gold nanoparticles (1-20 nm) are produced by reduction of chloroauric acid (H[AuCl4]), To the rapidly-stirred boiling HAuClsolution, 4 quickly add 2 mL of a 1% solution of trisodium citrate dihydrate, NaCHO.2HO. The gold 3657 2sol gradually forms as the citrate reduces the gold(III). Remove from heat when the solution has turned deep red or 10 minutes has elapsed.
  44. In cancer research, colloidal gold can be used to target tumors and provide detection using SERS (Surface Enhanced Raman Spectroscopy) in vivo. They are being investigated as photothermal converters of near infrared light for in-vivo applications, as ablation components for cancer, and other targets since near infrared light transmits readily through human skin and tissue
  45. Polymeric/Dendrimers (e.g.PLGA, PAA, PACA) spherical polymers of uniform molecular weight made from branched monomers are proving particularly adapt at providing multifunctional modularity.
  46. Polymeric PLGA POLY-LACTIC-GLYCOLIC ACID PLGA Poly-Lactic-GlycolicAcid
  47. Polyacrylamide (PACA)
  48. In solvente organico In acqua
  49. Dendrimers are repetitively branched molecules. PLGA PAA= POLI AMMINO AMMIDE PAA
  50. Polyamidoamines (PAA or PAMAM)
  51. HYDROGELS Co-polymers (e.g. acrylamide and acrylic acid) create water-impregnated nanoparticles with pores of well-defined size. Water flows freely into these particles, carrying proteins and other small molecules into the polymer matrix. By controlling the pore size, huge proteins such as albumin and immunoglobulin are excluded while smaller peptides and other molecules are allowed. The polymeric component acts as a negatively charged "bait" that attracts positively charged proteins, improving the particles' performance.
  52. Mesoporous silica (SiO2)
  53. Mesoporous silica particles: nano-sized spheres filled with a regular arrangement of pores with controllable pore size from 3 to 15nm and outer diameter from 20nm to 1000 nm . The large surface area of the pores allows the particles to be filled with a drug or with a fluorescent dye that would normally be unable to pass through cell walls. The MSN material is then capped off with a molecule that is compatible with the target cells. When are added to a cell culture, they carry the drug across the cell membrane. These particles are optically transparent, so a dye can be seen through the silica walls. The types of molecules that are grafted to the outside will control what kinds of biomolecules are allowed inside the particles to interact with the dye. EM
  54. Quantum dots Dots are crystalline fluorophores made of binary compounds such as lead sulfide, lead selenide, cadmium selenide, cadmium sulfide, indium arsenide, and indium phosphide. Dots may also be made from ternary compounds such as cadmium selenide sulfide. These quantum dots can contain as few as 100 to 100,000 atoms within the quantum dot volume, with a diameter of 10 to 50 atoms. This corresponds to about 2 to 10 nanometers. 3 nm
  55. A quantum dot is a semiconductor whose excitons are confined in all three spatial dimensions. An immediate optical feature of colloidal quantum dots is their coloration First attempts have been made to use quantum dots for tumor targeting under in vivo conditions. Generically toxic
  56. High quantum yield compared to common fluorescent dyes Broadband absorption: light that has a shorter wavelength than the emission maximum wavelength can be absorbed, peak emission wavelength is independent of excitation source Tunable and narrow emission, dependent on composition and size High resistance to photo bleaching: inorganic particles are more photostable than organic molecules and can survive longer irradiation times Long fluorescence lifetime: fluorescent of quantum dots are 15 to 20 ns, which is higher than typical organic dye lifetimes. Improved detection sensitivity: inorganic semiconductor nanoparticles can be characterized with electron microscopes 61 Quantum Dot Properties
  57. Quantum Dots • Raw quantum dots are toxic • But they fluoresce brilliantly, better than dyes (imaging agents) • Only way of clearance of protected QDs from the body is by slow filtration and excretion through the kidney
  58. Quantum Dots QD technology helps cancer researchers to observe fundamental molecular events occurring in the tumor cells by tracking the QDs of different sizes and thus different colors, tagged to multiple different biomoleules, in vitro by fluorescent microscopy. QD technology holds a great potential for applications in nanobiotechnology and medical diagnostics where QDs could be used as labels.
  59. Quantum Dots for Imaging of Tumor Cells Figure 2. Phase contrast images (top row) and fluorescence image NIH-3T3 cells incubated with QDs2; (c) SKOV3 cells were incubated with QDs2 64 FPP-QDs specifically bind to tumor cells via the membrane expression of FA receptors on cell surface Y. Zhao et al. Journal of Colloid and Interface Science 350 (2010) 44–50.
  60. 65 Quantum dots conjugated with folate–PEG–PMAM for targeting tumor cells Folate–poly(ethylene glycol)–polyamidoamine ligands encapsulate and solubilize CdSe/ZnS quantum dots and target folate receptors in tumor cells. Dendrimer ligands with multivalent amino groups can react with Zn2+ on the surface of CdSe/ZnS QDs based on direct ligand-exchange reactions with ODA ligands Y. Zhao et al. Journal of Colloid and Interface Science 350 (2010) 44–50.
  61. QD nanocrystals are highly toxic to cultured cells under UV illumination. The energy of UV irradiation is close to that of the covalent chemical bond energy of CdSe nanocrystals. As a result, semiconductor particles can be dissolved, in a process known as photolysis, to release toxic Metal ions into the culture medium. In the absence of UV irradiation, however, quantum dots with a stable polymer coating have been found to be essentially nontoxic. NP encapsulation of quantum dots allows for quantum dots to be introduced into a stable aqueous solution, reducing the possibility of Metal leakage.Then again, only little is known about the excretion process of quantum dots from living organisms.. ] These and other questions must be carefully examined before quantum dot applications can be approved for human clinical use.
  62. Nano-particulate pharmaceuticals Brand name Description Emend (Merck & Co. Inc.) Nanocrystal (antiemetic) in a capsule Rapamune (Wyeth-Ayerst Laboratories) Nanocrystallized Rapamycin (immunosuppressant) in a tablet Abraxane (American Biosciences, Inc.) Paclitaxel (anticancer drug)- bound albumin particles Rexin-G (Epeius Biotechnology corporation) A retroviral vector carrying cytotoxic gene Olay Moisturizers (Procter and Gamble) Contains added transparent, better protecting nano zinc oxide particles Trimetaspheres (Luna Nanoworks) MRI images Silcryst (Nucryst Pharmaceuticals) Enhance the solubility and sustained release of silver nanocrystals Nano-balls (Univ. of South Florida) Nano-sized plastic spheres with drugs (active against methicillin-resistant staph (MRSA) bacteria) chemically bonded to their surface that allow the drug to be dissolved in water.
  63. Company Product • CytImmune Gold nanoparticles for targeted delivery of drugs to tumors • Nucryst Antimicrobial wound dressings using silver nanocrystals • NanobiotixNanoparticles that target tumor cells, when irradiated by xrays the nanoparticles generate electrons which cause localized destruction of the tumor cells. • Oxonica Disease identification using gold nanoparticles (biomarkers) • Nanotherapeutics Nanoparticles for improving the performance of drug delivery by oral, inhaled or nasal methods • NanoBio Nanoemulsions for nasal delivery to fight viruses (such as the flu and colds) and bacteria • BioDelivery Sciences Oral drug delivery of drugs encapuslated in a nanocrystalline structure called a cochleate • NanoBioMagnetics Magnetically responsive nanoparticles for targeted drug delivery and other applications • Z-Medica Medical gauze containing aluminosilicate nanoparticles which help bood clot faster in open wounds
  64. Some liposome -based pharmaceuticals
  65. Open Problems Manufacturing NPs for medical use: Putting the drug on the particle Assessment of NPs: Dynamic structural features in vivo Kinetics of drug release Triggered drug release Maintaining the drug in the particle Making the drug come off the particle once application is done Purity and homogeneity of nanoparticles
  66. Open Problems Toxicity: short term - no toxicity in animals long term- not known Toxicity for both the host and the environment should be addressed
  67. Open Problems Delivery: Ensuring Delivery to target organ/cell SOLUTION: detection of NPs at target, organs , cells , subcellular location et al. Tissue distribution Removal of nanoparticles from the body
  68. Open Problems: Targeting the brain • Brain micro-vessel endothelial cells build up the blood brain barrier (BBB) • The BBB hinders water soluble molecules and those with MW > 500 from getting into the brain
  69. NPs The blood-brain barrier (BBB)
  70. Open Problems Good manufacturing practices (GMP) are the practices required in order to conform to guidelines recommended by agencies that control authorization and licensing for manufacture and sale of food, drug products, and active pharmaceutical products. These guidelines provide minimum requirements that a pharmaceutical or a food product manufacturer must meet to assure that the products are of high quality and do not pose any risk to the consumer or public. Good manufacturing practices, along with good laboratory practices and good clinical practices, are overseen by regulatory agencies in the United States, Canada, Europe, China, and other countries. GMP Challenges • No standards for: Purity and homogeneity of nanoparticles Manufacturing Methods Testing and Validation
  71. Summary • Toxicities of nanomaterials are unknown • to best target the nanomaterials so that systemic administration can be used • to uncage the drug so it gets out at the desired location • to “re-cage” the drug when it is no longer desired • Removal of nanoparticles from the body • Mathematical modeling of nanostructures • Barrier crossing (BBB, G.I., et al.) • GMP production