A Comparative Study Between Poly (Lactide-Co-Glycolide) Derived Composite Sintered Microsphere Scaffolds for Bone Tissue Engineering

Existing nanofibrous based tissue engineering scaffolds are poor in cell infiltration and mechanical stability. Microsphere based scaffolds can be suggested as alternative for this problem. Poly (lactide-co-glycolide) (PLGA) with lactide to glycolide ratio 85:15 was used to make virgin and composite microsphere based scaffolds. Nano Hydroxyapatite (nHAP) was synthesized, characterized and incorporated into microspheres to make 15% nHAP composite scaffolds. Microspheres of size range 250-500µm was used for making three scaffold types; virgin, composite and a combination of virgin/composite PLGA, by heat sintering method. Stainless steel molds were designed in cylindrical/rectangular shapes, followed by optimization in sintering time and temperature. Developed scaffolds were characterized through inverted microscope and scanning electron microscope (SEM), for surface-cross section morphology. Pore size distribution and porosity of the scaffolds were evaluated using liquid extrusion porosimetry and swelling studies respectively. Presence of nHAP in composite scaffolds was examined using Fourier Transform Infrared Spectroscopy (FTIR), Transmission electron Microscopy (TEM) and Energy Dispersive Spectrum (EDS). Effect of nHAP in physical properties of scaffolds was investigated through Thermo gravimetrical Analysis (TGA) whereas mechanical stability of the scaffolds from stress-strain curves of compression analysis. Swelling studies were performed to identify the percentage of water absorption, as an indication mark for the initiation of degradation. Bio activity of the scaffold was measured through in-vitro bio mineralization by PBS immersion method. A meaningful comparison between three scaffold types will provide a conclusive declaration for the selection of ideal scaffold for bone tissue engineering.