8 Jun 2011


Tissue engineering refers to the attention of the doctrine of engineering to cell culture pro the construction of functional anatomical units- tissues/organs. The take aim of tissue engineering is nothing but to supply the various body parts pro the renovate or replacement of damaged tissues or organs. It is currently doable to grow skin cells, blood cells cardiac cells and that. By using the skill of stem cells to breed and differentiate.

During the continue decade, the tissue culture bring about in animals demonstrated with the intention of effectively one creature tissue or organ can be developed in culture. This became doable single with it became renowned with the intention of the skill of educated cells to undergo differentiation can be restored. ‘Skin’ was the initially organ to be educated in reproduction media and may possibly be successfully used pro transplantation following serious skin burns. For earlier period hardly any years approximately of the biotech companies like ATS (Advanced Tissue Science, USA), Biosurface Technology (BTI, Cambridge) and Organogenesis, are rising reproduction skins to the stage of clinical trials.

Inside the meadow of tissue replacement, focus of attention is the Artificial cartilage. Equally it is not vascularized, it is not rejected due to immunogenic response. This will be inflicted with lots of implications in the behavior of sport correlated injuries and diseases like arthritis.

Design and engineering of tissues

The design and tissue engineering must in effect cause smallest ache to the uncomplaining. The damaged tissues must be straightforwardly fixed with the desired functions quickly restored. Another valuable thing scheming the crafty of tissue culture is the source of patron cells. The cells from the uncomplaining himself, is permanently preferred as it considerably reduces the immunological complications. However under particular situations allogeneic cells (cells taken from a person other than the patient) are furthermore used. The other valuable factors are –the support material, it’s degradation products, cell hold characteristics and that. It was demonstrated in 1975 with the intention of creature keratinocytes may possibly be developed in the laboratory in a form apposite pro grafting. A unremitting sheet of epithelial cells can be developed currently however here is still trying to grow TE skin with the dermal layer with all the blood capillaries, nerves, sweat glands, and other belt organs.

Some of the implantable skin substitutes which are tissue engineering skin constructs with a restricted shelf life of in this area 5 days are:
A) Integra TM – A bioartificial material collected of collagen-glycosaminoglycan and is primarily used to involve the seeded cells.
B) DermagraftTM- This is collected of poly glycolic acid polymer mesh seeded with creature dermal fibroblasts from neonatal foreskins.
C) ApligrafTM- It is constructed by seeding creature dermal fibroblasts into collagen gel with the placement of a layer of creature keratinocytes on the high go up.

These tissue constructs integrate into the surrounding habitual tissue and form a skilled skin cover with smallest immunological complications.

The urothelial cells and smooth muscle cells from bladder are currently being educated and attempts are on to construct TE urothelium. Some progress has furthermore been made in the renovate of injured peripheral nerves using tissue engineered peripheral nerve implants. The renaissance of the injured nerve occurs from the proximal baffle to retort by distal baffle.

The renaissance process requires substances like-
(a) Conduct material- The conduct material is collected of collagen- glycosaminoglycans, PLGA (poly lactic- co- glycolicacid), hyaluronan and fibronectin and forms the outer layer.
(b) Filling material- The big material contains collagen, fibrin, fibronectin and agarose. This chains the neural cells pro renaissance. And
(c) Additives- A generous digit of other factors are furthermore added e.G. Growth factors, neurotrophic factors such as fibroblast growth thing (FGF), nerve growth thing (NGF).

 The other valuable applications of tissue engineering are in gene therapy, pseudo-organs and as develop cell systems pro rising extra remedial approaches to creature diseases.The attempts are on to create tissue models in the form of reproduction organs using tissue engineering. The reproduction liver is being produced using hepatocytes educated as spheroids and held floating in reproduction support logic such as porous gelatin sponges, agarose or collagen. Some progress has been made in the area of creating the reproduction pancreas using spheroids of insulin secreting cells which be inflicted with been urban from mouse insulinoma beta cells.

Three dimensional brain cell cultures be inflicted with been used pro the study of neural myelination, neuronal renaissance, and neurotoxicity of principal. The aggregated brain cells are furthermore being used to study Alzheimer’s disease and Parkinson’s disease. Thyroid cell spheroids are being used to study cell hold, motility, and thyroid follicle biogenesis. (Table 8.2 leaf 155, gupta)

Table depicting the technological goals and areas of investigate in tissue engineering

·         Growth of cells in three- dimensional systems
·         Delivery systems pro protein therapeutics
·         Cell encouragement methods pro culturing ‘recalcitrant cells’
·         Expression of transgenic proteins in transplantable cells
·         To develop vehicles pro delivering transplantable cells
·         Development of markers pro tracking transplanted cells
·         Avoiding immunogenicity in transplantable cells
·         Development of in vivo and past vivo biosensors pro monitoring cell
·         Behaviour all through tissue production


Downstream dispensation or downstreaming is the extraction and refining of the desired aim products of fermentation processes. Such products might include cells, solvents or solutes. Various processes are unfilled pro the separation of cells from the fermentation gumbo in which they are developed, counting flocculation, filtration, centrifugation, sedimentation or flotation. The procedure adopted depends on whether it is the cells, or the solution surrounding them, with the intention of contains the desired aim products.

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