Preparation, characterization, and in vitro biological performance of novel porous GPTMS-coupled tragacanth/nano-bioactive glass bone tissue scaffolds

Abstract

Gum tragacanth (GT) as an interesting biocompatible hydrophilic polysaccharide along with widely-used bioactive glass nanoparticles (BGNPs) could possibly provide a novel and promising combination as bone tissue engineering (BTE) scaffolds. Accordingly, in the present study, composite scaffold formulations of GT matrix and increasing amounts of BGNPs (1−4 wt. %) were successfully fabricated by freeze-drying method and thoroughly characterized. The crosslinking ability of 3-glycidoxypropyltrimethoxysilane (GPTMS) as a silane-coupling agent was also employed to improve stability of GT. Morphological observations by scanning electron microscopy (SEM) and porosity measurements revealed proper structure of scaffolds with interconnective pores in a size range of tens of microns to hundreds of micrometers and porosity of ∼ 75–90 %. SEM observations, Fourier transform infrared spectroscopy (FTIR), and X-ray diffractometry (XRD) analysis of the samples after immersion in SBF, confirmed bioactivity potency introduced by BGNPs into GT matrices. The presence of BGNPs in composite scaffolds composition affected the uniformity of GT structure and enhanced degradation rate of the samples as proved by inductive coupled plasma-atomic emission spectroscopy (ICP-AES) analysis and weight loss measurements. The results of compressive mechanical testing approved reinforcing effect of BGNPs, while the GT scaffold and composite samples showed compressive strength of about 0.170, 0.212−0.345 MPa and Young’s modulus of 245 and 318–585 kPa, respectively. In vitro cellular tests also revealed that the added BGNPs could significantly promote biological response of the scaffolds. The new composite scaffolds prepared in this work, specifically those containing higher amounts of BGNPs, showed promising characteristics for BTE applications.