Tissue Engineering Tissue engineering is TECHNOLOGY. Similar to REGENARATIVE MEDICINES. Regenerative medicines means use of STEM CELLS. STEM CELLS: 1. Embryonic stem cells 2. Adult stem cells
Sources of cells Primary source – cells from individual(patient) Secondary source- cells from cell bank Autologous cells- cells from same person Allogenic cells-cells from same species Xenogenic cells- cells from another species Syngenic cells- cells from clones
Scaffolds Cells are implanted or seeded into an artificial structure capable of supporting three-dimensional tissue formation. These structures typically are called as scaffolds Scaffolds usually serve at least one of the following purposes: Allow cell attachment and migration Deliver and retain cells and biochemical factors Enable diffusion of vital cell nutrients and expressed products
Requirements for scaffolds High porosity and an adequate pore size Biodegradability rate at which degradation occurs has to coincide as much as possible with the rate of tissue formation Inject ability
Carbon Nanotube Carbon nanotubes are among the numerous types for tissue engineering scaffolds They are- biocompatible, can be functionalized with biomolecules.
Methods for tissue engineeringscaffolds:Solvent Casting & Particulate Leaching (SCPL) It allows for the preparation of porous structures with regular porosity, but with a limited thickness Polymer- polylactic acid Solvent- dichloromethane Porogen- sodium chloride, crystals of saccharose, gelatin spheres or paraffin spheres
Gas Foaming To overcome the need to use organic solvents and solid porogens Disc-shaped structures made Exposed to high pressure CO2 for several days Pressure inside the chamber is gradually restored to atmospheric levels Pores are formed by the carbon dioxide molecules that abandon the polymer
Emulsification/Freeze-drying This technique does not require the use of a solid porogen A synthetic polymer is dissolved into a suitable solvent Water is added to the polymeric solution to obtain emulsion Emulsion is cast into a mold and quickly frozen Frozen emulsion is subsequently freeze-dried to remove the dispersed water and the solvent
CAD/CAM Technologies Three-dimensional structure is designed using CAD software. The porosity can be tailored using algorithms within the software
Tissue culture Includes creation of functional tissues and biological structures in vitro It requires extensive culturing to promote survival, growth and inducement of functionality The major problem is maintaining culture conditions
Bioreactors •Bioreactor is a device that attempts to simulate a physiological environment in order to promote cell or tissue growth in vivo
Market scenario Treatments via cell therapy and tissue engineering constitute a $6.9 billion worldwide market. Market is predicted to grow nearly $32 billion in less than ten years. Market is growing at rate of 16%. Market demand increasing for innovative product. Over the 2009–2018 period, - organ transplantation segment is expected to grow by 46%. - dental decay and disease segment expected to grow by 21%. Increase in Indian tissue engineering market due to Medical tourism
Apligraf, by Organogenesis, is the first manufactured living human organ in 1997 Different product categories: − Skin substitutes − Orthopedic cartilage and bone replacement − Cardiovascular substitutes − Organs (e.g. kidney, liver, lung) − Nervous system − Soft tissue
Market segment andopportunitiesOrthopedics: Orthopedic segment grow at nearly 15% per year This market include spine, bone grafts, and bone substitutes. Regenerative medicine therapy is favorable. Orthopedic treatment is most popular area in Indian medical tourism. Cardiology: Regenerative medicine with applications in cardiology and vascular medicine will rank among the three fastest growing segments . As CHD (and CVD) rates increase, estimate increases to 17.9 million by 2030. In 2005, India was estimated to have 3.5 crore CHD patients while in 2010, the number stood at 4.6 crores. The most promising area for regenerative medicine is the treatment of myocardial infarction
Wound healing Globally, 500,000 surgeries were performed to treat diabetic ulcers 500,000 surgeries to treat venous ulcers 45,000 burn surgeries 940,000 plastic surgeries are performed each year The most common application for regenerative medicine is for the treatment of burns.
Diabetes: The number of people with diabetes globally will likely double between 2003-2030. An estimated 285 million people, corresponding to 6.4% of the worlds adult population, will live with diabetes in 2010 Surgical transplantation of pancreatic islet cells is promising applicationNeurodegenerative diseases: 18 million people worldwide with Alzheimer’s disease. 20 million people each year will suffer from stroke. 6.3 million people have Parkinson’s disease.
Challenges: Quality control of the materials used in various surgical applications Acquiring a fundamental understanding of tissue differentiation mechanisms The industry is challenged to develop tissue- engineered products for a number of surgery- related applications, Ethical issue..
Future: Technical advances in the various components of the industry will contribute to market growth. Focus on the safety and efficacy standards. Continued development of artificial organs with appropriate support structures. Focus on disease areas that have the most patients and the largest unmet needs
Problems with Tissue engineering Complexity using Human tissue implants Variability of cells grown. Standardization of process Irreversible process Risk assessment in clinical trials & commercialization. Ethical problems
Ethical problems•Using Xenogenic cells: Species boundaries crossed•Using Human embryonic cells: Unethical to use humanembryo & aborted fetus.•Use of human embryo with large scale cultivation for profit•Rights of Tissue Donors: -Profit making -Information
Ethical Problems Role of Cell banks: Privacy of Donor Prolonging of life through Tissue engineering: Set goal for raising life span through tissue engineering Playing THEE!!! Organ trafficking Cost of using Technology.
Organizations in TE Society for Tissue Engineering and Regenerative Medicine (India) (STERMI) Society for Biomaterials & Artificial organs Society for regenerative medicines & tissue engineering (SRMTE) European tissue repair society Tissue & cell engineering society Tissue engineering & Regenerative Medicine International Society