
Low-cost bone graft for bone reconstruction
Faculty: Prof. Jayesh Bellare, Chemical Engineering
Tata Fellow: Deepak Gupta (2014-16)
The damage of bone tissue occurs due to trauma, osteonecrosis and tumours. The treatments for bone loss due to the above conditions are challenging. Bone grafts are frequently used in surgical interventions for such skeletal deficiencies and are second to blood transfusion on the list of transplanted materials. In bone replacement, the orthopaedic surgeon or dentist currently employs several methods such as autologous or allogeneic, cancellous or cortical bone, demineralised bone matrix, calcium phosphate-based bone-graft substitute, or autologous bone marrow. Allo-and xenografts may lead to the problem due to immunologic host reactions. Autografts are limited and the associated morbidity due to a second surgery is a major hindrance to their use, and allografts are known to cause disease transmission. So there is a need to substitute natural bone grafts. There are products in the market as bone substitutes but are in powder form to fill the defects, they cannot match the defect size and load bearing. The major problem of the scaffolds that are being developed nowadays is they do not have resiliency and stress recovery capacity after the application of the force and they also fail to promote healing at the site of bacterial infection. There is no such treatment available which can be used and which can provide mechanical stability and fit exactly into any complex large defect, heal the defect at the same time and deal with the infection. The bigger problem in India is most of the patients do not use any or synthetic bone graft which reduces their quality of life therefore, leading to jaw fractures or losing teeth.
This project addresses the problem by bringing universal and customized bone graft which will not only eliminate the use of autograft with the second surgical site but will also bring down the cost and healing time, thereby benefitting 2 per cent of the total Indian population suffering from bone voids. Also, maxillofacial and orthopaedic surgeons have shown great interest in such products to be developed. There are various methods of preparation techniques of scaffolds like phase separation, particulate leaching, fiber bonding, electro-spinning, gas foaming, 3-D printing and others. In this work, 3-D printing from the fused deposition modeling technique is used with bio-compatible and bio-resorbable polymers for scaffold fabbrication. 3-D printing has allowed us to customize micro-porosity in terms of pore size, pore shape and overall porosity by modifying the internal structure and the interconnectivity among the pores of the scaffolds. The designs are created using Solidworks software and Python programming to generate the .gcode file for 3-D printing. Micro-porous scaffolds have been prepared using filaments of different polymers and different porosities can be incorporated into the same scaffold. A filament extruder is used to extrude the filaments out of polymeric beads. Characterization of the scaffolds has also been performed which includes TGA analysis, mechanical testing, porosimetry and bio-compatibility test. In the future, we will be using different blends of polymers for printing the scaffolds.