Mineralised Biopolymer-Based Scaffolds Containing Natural Bioactive Compounds for Bone Tissue Engineering

Introduction

Large bone defects remain a significant clinical challenge due to the limited intrinsic regenerative capacity of bone tissue and the insufficient bioactivity of conventional scaffolds. This study aims to develop a multifunctional biomimetically mineralised scaffold integrating natural polymer networks, bacterial cellulose reinforcement, in situ-formed hydroxyapatite (HAp), and phytochemical bioactive compounds to enhance bone regeneration.

Methods

A porous scaffold composed of gellan gum (GG), carboxymethyl chitosan (CMCs), and bacterial cellulose (BC) was fabricated via freeze-drying. Biomimetic mineralization was performed by immersing the scaffold in fivefold concentrated SBF supplemented with Cissus quadrangularis extract. The formation and distribution of HAp were characterized using SEM, EDS, FTIR, and XRD. Physicochemical properties of scaffold were evaluated through swelling behavior, porosity, and compressive strength testing. Biological performance was assessed via hemolysis assay, cell viability assay, and Alizarin Red S staining for osteogenic differentiation.

Results

Uniform HAp deposition on the scaffold surface was confirmed by SEM imaging and further validated by FTIR and XRD analyses. The composite matrix preserved its interconnected and homogeneous porous architecture after mineralization. Excellent hemocompatibility was observed, with a hemolysis rate of 1.9%. Cell viability exceeded 100% relative to the control group, indicating favorable cytocompatibility and potential proliferative stimulation. Osteogenic differentiation was markedly enhanced, as quantified by Alizarin Red S staining, with mineral deposition levels reaching 0.794 ± 0.128, nearly six-fold higher than the control group (0.1457 ± 0.0031).

Conclusions

The synergistic integration of natural polymer networks, bacterial cellulose reinforcement, biomimetic mineralization, and plant-derived bioactive molecules resulted in a multifunctional scaffold with enhanced osteogenic potential. This strategy provides a promising platform for advanced functional biomaterials in bone tissue engineering applications.