Third-Generation Biomedical Materials :Third-Generation Biomedical Materials Larry L. Hench and Julia M. Polak Department of Materials and the Tissue Engineering Centre, Imperial College of Science, Technology and Medicine, University of London, Prince Consort Road, London SW7 2BP, UK. Mohana Marimuthu - 200840090 College of bio nanotechnology Kyungwon university


Overview :Great Word features Overview First generation biomaterials Second generation biomaterials Third-Generation Biomaterials: Cell and Gene-Activating Materials Genetic Control and Activation Molecularly Tailored Resorbable Polymers Implications for the Future


First generation biomaterials :Great Word features First generation biomaterials 1960s and 1970s Goal – “ achieve- physical properties- replacement tissue- immune response in host”. 1980s – 50 implantable devices – 40 different materials Common feature – “biological inertness”


Second generation biomaterials :Great Word features Second generation biomaterials 1st generation “Bio-inert” 2nd generation “bioactive” Example: Mechanism of bonding of bioactive glass with living tissue Formation of bone


Slide 5:Great Word features Bioactive glass SiOH bond Adsorption - bio moieties Si-O-Si Crystal- HCA Adsorption Ca+Po4+Co3 Action Macrophages Stem cells Differntiation Matrix formation Crystal matrix Bone Formation Reactions in forming a bond between tissue and bioactive glasses


Biomaterials in tissue replacement :Great Word features Biomaterials in tissue replacement


Slide 7:Great Word features In mid 1080s and 1990s development of HA, bioactive Glasses and glass ceramics bone fixation, middle-ear prostheses, replacement of vertebra Another advancement – Resorbable biomaterials No difference between implant site and host tissue


Slide 8:Great Word features Example: PLA and PGA Co2 +H2O Survival analysis - skeletal prostheses & artificial heart valves – Failure 10-25 years – revision surgery Main disadvantage: Living tissue – changes with physiological load and biochemical stimuli but not implanted biomaterials hydrolysis


Third-Generation Biomaterials: Cell and Gene-Activating Materials :Great Word features Third-Generation Biomaterials: Cell and Gene-Activating Materials stimulate specific cellular responses at the molecular level Two alternative routes of repair 1. Tissue engineering


Slide 10:Great Word features 2. In situ tissue engineering Form of powders, solutions, or doped microparticles to stimulate local tissue repair. ionic dissolution products, or growth factors (BMP) Activate the cells Cells Stimulate multiple generations of growing cells to self-assemble into the required tissues in situ


Genetic control and activation :Great Word features Genetic control and activation Human osteoblasts – ionic dissolution products of bioactive glasses – up regulates seven families of genes Activated genes – stimulates – differentiation and proliferation of osteoblasts (i) transcription factors and cellcycle regulators; (ii) signal transduction molecules; (iii) proteins involved in DNA synthesis, repair, and recombination;


Slide 12:Great Word features (iv) growth factors and cytokines that influence the inflammatory response to the material; (v) cell-surface antigens and receptors; (vi) extracellular-matrix components; and (vii) apoptosis regulators.


Molecularly Tailored Resorbable Polymers :Great Word features Molecularly Tailored Resorbable Polymers Immobilizing specific proteins, peptides, and other biomolecules - material - mimic ECM environment - multifunctional cell adhesive surface PLA/PGA copolymers were used to incorporate nerve growth factor (NGF) Molecularly tailored polymers – regeneration of nerves


Implications for the Future :Great Word features Implications for the Future Third-generation biomaterials - molecular design of scaffolds for tissue engineering and for in situ tissue regeneration and repair, with minimally invasive surgery. Economic advantage Patient specific treatment


Slide 15:Great Word features Questions


Slide 16:Great Word features Thank you