Bone is a extremely specialised support tissue, which is characterized by its rigidness and hardness. The major maps of bone are supplying structural support for the organic structure, supply protection of critical variety meats and supply an environment for marrow. Bone is the lone tissue that undergoes uninterrupted reconstructing throughout life and is one of the few variety meats that retains the potency for regeneration in big life. ( 1, 2 ) Bone regeneration is required to accomplish break healing and bone loss or bone tumours. Bone loss may be due to aging, periodontic reabsorption, osteoporosis, arthroplasty and accidents.
The evident lessening in bone mass is the major cause for bone breaks and bone loss ( 3 ) . The relationship surveies between the age and bone loss in assorted castanetss are explained in the fallowing tabular column 1. It is clear that lessening in bone mineral denseness in castanetss is the ultimate cause of bone loss which farther leads to breaks and associated complications.
Tissue Engineering ( TE ) , as a possible medical intervention holds promises of extinguishing re-operations by utilizing biological replacements and solves the jobs of implant rejection, transmittal of diseases associated with heterografts, allografls and deficit in organ contribution [ 4 ] . With addition in the elderly population and the demand to widen mean single wellness span, tissue technology with biomaterials have an progressively of import function in the development of new coevals medical devices and drug bringing systems ( 5 ) . Bone tissue technology a multidisciplinary scientific discipline using the rules of biological science and technology in developing feasible replacements that restore and keep the map of human bone tissues.
Implants in Tissue Engineering:
One of the rule methods in tissue technology involves turning the relevant cell ( s ) in vitro into the needed 3-dimensional ( 3D ) organ or tissue. But cells lack the ability to turn in favorite 3D orientations and therefore specify the anatomical form of the tissue. Alternatively, they randomly migrate to organize a planar ( 2D ) bed of cells. However, 3D tissues are required and this is achieved by seeding the cells onto porous matrices, known as scaffolds, to which the cells attach and colonize ( 6 ) . The scaffold therefore is a really of import constituent for tissue technology. Major issues in planing tissue technology scaffolds are usage of appropriate matrix stuffs for scaffolds. Pore features, mechanical strength, osteoconductivity & A ; osteoinductivity are compulsory demands for a scaffold [ 7, 13 ] . Many different stuffs ( natural, man-made, biodegradable and lasting ) have been investigated. Most of these stuffs have been known in the medical field before the coming of tissue technology as a research subject, being already employed as bioresorbable suturas.
Figure 1: ( A ) Porous Ti scaffold with 59.1 % porousness. ( B ) Porous Ti scaffolds with 200, 300, and 400A I?m pore sizes.
The new coevals biomaterials include metals of Titanium ( Ti ) , polymers and bioceramic implants. Since cells are inherently sensitive to their milieus, the public presentation of biomaterials strongly depends on their initial interaction with a biological environment ( 5 ) . Therefore, the surface belongingss of biomaterials are associated with cell adhesion and subsequent assorted cell behaviours such as proliferation, migration, distinction and programmed cell death. In the field of bone tissue technology, difficult tissues like bone and gristle were substituted with “ hydroxyapatite ( HAp ) ” and “ Tricalcium phosphate ceramics ( TCP ) ” , because all natural difficult tissues are chiefly composed of hydroxyapatite ( HAp ) . In effect, the nanoscale topography of Ca phosphate ceramics determines the cellular public presentation of mesenchymal root cells and osteoblast cells. Osteoblast proliferation was reported to be enhanced on HAp.
Figure 2: Pressed Green & A ; Sintered Hydroxyapatite. Figure 3: Hydroxyapatite Foam
Figure 4: Pressed Sintered Tricalcium Phosphate.
Stem Cells in Tissue Engineering:
Stem cell primogenitor cells act as a fix system in side the organic structure, which replenish and keep the normal turnover of specialised cells in regenerative medical specialty. Based on there potency root cells are classified chiefly in to two multipotent root cell types, they are Mesenchymal Stem Cells ( MSC ‘s ) giving rise to connective tissue have tremendous curative potency to distinguish into multiple cell types including osteocytes, adipocytes, chondrocytes and cardiomyocytes and Hematopoietic Stem Cells ( HSC ‘s ) for blood regeneration [ 8,9 ] . Stem cells can now be grown and transformed into specialised cells with features consistent with cells of assorted tissues such as blood, bone tissue, etc.
Although the bone marrow serves as the primary reservoir for MSCs, draw outing bone marrow from the patient is an invasive process and in add-on, it has been demonstrated that the figure and the distinguishing potency of bone marrow MSCs decreases with age [ 10 ] . Therefore hunt for alternate beginnings of MSCs has aquired greater significance. MSCs presence has been reported in a assortment of other tissues including amnionic fluid, cord blood, peripheral blood, fallopian tubing, etc [ 11 ] .
Fig.1: Stem cell distinction Fig.2: MSC ‘s merging civilization
Cord Blood Stem Cells:
More late UCB has been examined for the presence of cells capable of distinguishing into cell types of all three embryologic beds ( ecto, endo and meso-derm ) . MSCs from Human Umbilical Cord Blood ( UCB ) show higher multipotentiality than big marrow-derived MSCs. Other most of import advantages of utilizing cord blood as a beginning of root cells are its non-invasive procurance and its huge copiousness ; 1000s of babes are born each twenty-four hours ( 12 ) . Until late, umbilical cord blood was discarded after birth, along with the placenta. Now, in several states around the universe, cord blood is collected and banked in public Bankss for medical intent.
Figure: Umbilical cord blood aggregation
MSC ‘s shown to renew functional bone tissue when delivered to the site of musculoskeletal defects in experimental animate beings. We can besides heighten the Invitro osteogesis by utilizing fresh osteoblast distinction advancing compound like BMPs ( Bone Morphogenic Proteins ) & A ; TGF ( Transforming Growth Factors ) ( 13 ) .
Beginning of the Proposal:
Although several major advancements have been introduced in the field of bone regenerative medical specialty during the old ages, current therapies, such as bone transplants still have many restrictions. Furthermore, and in malice of the fact that stuff scientific discipline engineering has resulted in clear betterments in the field of bone permutation medical specialty, no equal bone replacement has been developed and therefore big bone defects/injuries still represent a major challenge for orthopaedic and rehabilitative sawboness. It is in this context that TE has been emerging as a valid attack to the current therapies for bone regeneration/substitution. The proposal gives an thorough overview on constituents needed for doing bone tissue technology a successful therapy.
Definition of the Problem:
One of the chief lessons tissue applied scientists have learned from their experiences over the last 15 old ages is that the simple placing of biological constituents in contact with a given stuff is non sufficient. It is instead the specific attack used when uniting the two which is critical. The basic thought underlying classical tissue technology has been that the seeding of life cells onto a biocompatible and finally biodegradable scaffold followed by the culturing of this system in a bioreactor would take to the initial cell population spread outing into a tissue.
1. Procedure Optimization for MSC ‘s Differentiation and Maintenance from the
Umbilical Cord Blood ( UCB ) mononuclear cells.
2. Implant Selection & A ; Design for In-vitro Osteogenic Differentiation Studies.
3. Testing the in- vivo Efficiency of the Implants ( cell seeded ) on Small
experimental animate beings.
Animal Cell Culture installations, Assistance from Material Science Department for implant design, carnal house ( little animate being ) for in vivo surveies.
Previous experience in the field: 1 twelvemonth ( On bench, functionary and Purchases )
Paper presentation in Asiatic Bioceramic Conference ( ABC-2008 ) at IIT madras Rajyalakshmi, Sarika Mishra, M. Naveen Kumar and Balasubramanian. . ” Adhesion Patterns of Haematopoietic Stem Cells on Porous Titanium and Bioceramic Scaffolds- an in-vitro survey.