Research Projects

Bone fracture is one of the very common injuries and the traditional implants made of Ti, SS, Co-Cr etc used to treat bone fracture can cause long term problems, including tissue damage, implant rejection, and infection. The need for re-surgery to take out the implant adds to the extra cost. Likewise, the calvarial defect treatment has been an area of concern due to the low capability of adults to regenerate a significant calvarial defect. The titanium mesh, polymethyl methacrylate (PMMA) and bone allografts used to treat calvarial defects have limitations as well. To address these drawbacks focus has been on Biodegradable implants over the last few decades. Absorbable metallic materials such as Fe, Mg, Zn are suitable for these applications. Among these, Mg is more suitable due to its biocompatibility, reasonable good mechanical properties with low modulus (nearer to that of bone). However, the challenge is to tailor the degradation of Mg implants with that of healing rate of the bone or tissue. In the recent times, significant process has been achieved in the field of Mg biomaterials and few Mg alloy based products are already introduced by various manufactures such as M/s. Biotronik Ltd., Germany, M/s. Syntellix, Germany. Recently, SRS Life Sciences, Singapore got approval for human trail in India during 2023. Unfortunately, not much advancement taken place in India apart from few in-vitro studies on the different coatings developed for Mg alloys in bio applications. Alloy development and complete understanding on the behavior of Mg alloys in-vivo are lacking. In a recently concluded SERB project (completed in January 2022), PI developed Mg-RE based alloys that showed excellent tensile and degradation properties with good in-vitro cyto compatibility. Based on the in vitro results, Mg-10Gd-1Zn alloy was subcutaneously implanted in Sprague dawley rats for different periods of time. Although the degradation resistance was low after 1-month implantation period, the alloys degraded rapidly beyond 1 month and the samples dissolved completely before completing 2 months’ implantation time. It was identified that the higher degradation rate was due to the impurities in the castings as the raw materials used for the alloy preparation were commercially pure. Hence, the work proposes to further reduce the degradation rate of the alloys by using ultra high pure raw materials for fabrication of Mg alloy and to investigate in detail the in-vivo behavior of the selected Mg alloy in rabbit using Calvarial model and fracture model. Mg-10Gd-1Zn alloys produced through casting route followed by extrusion and then subjected to in-depth in-vitro behavior will be used for in-vivo studies. The complete understanding of the in-vitro and in-vivo behavior of these Mg alloys will enhance the knowledge and facilitate the development of Mg based degradable products for biomedical applications.