Effects of Micro and Nano β-TCP Fillers in Freeze-Gelled Chitosan Scaffolds for Bone Tissue Engineering

Tissue engineering holds an exciting promise in providing a long-term cure to bone-related defects and diseases. However, one of the most important prerequisites for bone tissue engineering is an ideal platform that can aid tissue genesis by having biomimetic, mechanostable, and cytocompatible characteristics. Chitosan (CS) was chosen as the base polymer to incorporate filler, namely beta-tri calcium phosphate (beta-TCP). This research deals with a comparative study on the properties of CS scaffolds prepared using micro- and nano-sized beta-TCP as filler by freeze gelation method. The scaffolds were characterized for their morphology, porosity, swelling, structural, chemical, biodegradation, and bioresorption properties. Rheological behavior of polymer and polymer-ceramic composite suspensions were analyzed and all the suspensions with varying ratios of beta-TCP showed non-Newtonian behavior with shear thinning property. Pore size, porosity of micro-and nano-sized composite scaffolds are measured as 48-158 mu m and 77% and 43-155 mu m and 81%, respectively. The scaffolds containing nano beta-TCP possess higher compressive strength (similar to 2.67 MPa) and slower degradation rate as compared to composites prepared with micro-sized beta-TCP (similar to 1.52 MPa). Bioresorbability, in vitro cell viability by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, proliferation by Alamar blue assay, cell interaction by scanning electron microscope, and florescence microscopy further validates the potentiality of freeze-gelled CS/beta-TCP composite scaffolds for bone tissue engineering applications. (C) 2014 Wiley Periodicals, Inc.