Investigation of 3D printed biodegradable PLA orthopedic screw and surface modified with nanocomposites (Ti-Zr) for biocompatibility

The orthopedic implants were fabricated using stainless steel and titanium alloys, which provide the strength necessary to support the mechanical movements of a bone. The usage of the non-biodegradable material as the medical implant requires post-surgically removal and replacement after a certain period of time. There is a need for the production of orthopedic implants that are based on biocompatible and biodegradable materials. To solve this problem biodegradable material, PLA Poly (lactic acid) was introduced to make an implant, which has a high degradation property and good biocompatibility with the human body. The orthopedic implant (degradable screws) was designed using Solidworks software. Mechanical simulation studies were done in Ansys software for the designed orthopedic implant (degradable screws) and the 3D models were printed using a 3D printer with PLA material. To improve the mechanical and biological properties of the implant, the surface was modified with nanocomposites (TiO2+ZrO2) by the dip-coating method. The confirmation of the presence of nanocomposites and substrate elements was done by various characterization techniques X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR). The morphological and elemental changes of the implant surface were analyzed by Field emission scanning electron microscopy (FESEM) with an Energy-dispersive Spectrometer (EDS). In vitro, the osteointegration of implants was investigated using cell viability and Hank's Balanced Salt Solution (HBSS). The viability of the cells shows that osteointegration improved as the number of days of treatment was prolonged, and recommended to use as an orthopedic implant in biomedical applications.