Preparation, characterization, and bioactivity of reinforced monetite with chitosan-gelatin electrospun composite scaffold for bone tissue engineering

Abstract

In this study, chitosan-gelatin-monetite (CGM)-based electrospun scaffolds have been developed that closely mimicked the microstructure and chemical composition of the extracellular matrix of natural bone. CGM-based nanofibrous composite scaffolds were prepared with the help of the electrospinning technique, post-cross-linked using ethyl(dimethylaminopropyl)carbodiimide and N-hydroxysuccinimide solution to improve their stability in an aqueous environment. The prepared chitosan/gelatin (CG) scaffold showed an average fiber diameter of 308 ± 17 nm, whereas 5 and 7 wt% monetite containing CGM₅and CGM₇scaffolds, exhibited an average fiber diameter of 287 ± 13 and 265 ± 9 nm, respectively, revealing the fine distribution of monetite particles on the fibrous surface. The distribution of monetite nanoparticles onto the CG nanofibrous surface was confirmed using x-ray diffraction, Fourier transform infrared, and EDAX. Moreover, the addition of 7 wt% monetite into the CG electrospun matrix increased their ultimate tensile strength from 7.62 ± 0.13 MPa in the CG scaffold to 14.34 ± 0.39 MPa in the CGM₇scaffold. Simulated body fluid study and staining with alizarin red S (ARS) confirmed the higher mineralization ability of monetite-containing scaffolds compared to that revealed by the CG scaffold. The monetite incorporation into the CG matrix improved its osteogenic properties, including pre-osteoblast MG-63 cell adhesion, proliferation, and differentiation, when seeded with the cells. A higher degree of cellular adhesion, spreading, and migration was observed on the monetite-incorporated CG scaffold than that on the CG scaffold. From 3-(4, 5-dimethylthiazol-2-yl-2, 5-diphenyltetrazolium bromide) MTT assay, alkaline phosphatase activity, ARS staining, and immunocytochemistry study, the cultured cells discovered a more conducive microenvironment to proliferate and subsequently differentiate into osteoblast lineage in contact with CGM₇nanofibers rather than that in CGM₀and CGM₅.In-vitroresults indicated that electrospun CGM-based composite scaffolds could be used as a potential candidate to repair and regenerate new bone tissues.

Keywords: bioactive nanoparticles; bone tissue engineering; chitosan; gelatin; nanofibrous scaffold; osteogenic properties.