Synergistic reinforcement of regenerated silk fibroin with LAPONITE® and organomodified montmorillonite for bone tissue engineering

Abstract

Bio-nanocomposite films were developed using various blending ratios of tetra octadecyl ammonium bromide-modified montmorillonite (MMT), LAPONITE® (LAP), and silk fibroin (SF) as the polymer matrix. SF was extracted from Bombyx mori cocoons via degumming and NaOH hydrolysis. To enhance its mechanical properties, SF is reinforced with LAP and modified MMT using a solution casting method. Characterization included mechanical testing, XRD, FTIR, and FESEM with EDX and mapping. The resulting 1 wt% film showed increased thickness (0.083 ± 0.003 mm), Young's modulus (17.26 ± 1.02 GPa), tensile strength (132.53 ± 3.383 MPa), and elongation at break (%) (0.48 ± 0.0089%), respectively. The bioactivity of the 1 wt% film was assessed by SBF immersion at 37 °C for 7, 14, and 21 days, while biodegradation was evaluated in PBS (pH 7.4) over 1 to 28 days. The biocompatibility was confirmed by Saos-2 cell culture and MTT assay, with cell viability improving over time. The presence of surface pores and apatite confirmed the bioactivity, positioning these films as promising candidates for bone tissue engineering due to their mechanical strength, biodegradability, thermal stability, and cytocompatibility.