Investigation of functionalized-MWCNT/hydroxyapatite/gelatin nanocomposite scaffolds for bone tissue regeneration: Synthesis and characterization

Abstract

Bone scaffolds are essential in regenerative medicine, yet they often face critical limitations, including insufficient mechanical strength, poor bioactivity, and inadequate structural mimicry of the native bone tissue. In contrast, nanotechnology offers promising solutions by enabling the incorporation of nanoscale reinforcements that enhance both mechanical and biological properties. Among these, functionalized carbon nanotubes have shown exceptional potential due to their high tensile strength, surface functionalizability capability, and ability to promote cellular interactions. In this study, we developed a three-dimensional porous nanocomposite scaffold using a freeze-drying technique. The scaffold was composed of hydroxyapatite (HA) nanopowders as the mineral phase and microbial-derived gelatin cross-linked with EDC (N-(3-dimethylaminopropyl)-N′-ethylcarbodiimide hydrochloride) as the organic matrix, mimicking the natural composition of bone. To enhance the mechanical integrity, functionalized multi-walled carbon nanotubes (ƒ-MWCNTs) were incorporated at controlled concentrations. Structural and morphological analyses using Fourier-transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) confirmed the uniform distribution of both hydroxyapatite (HA) and ƒ-MWCNTs within the gelatin matrix, along with a well-defined, interconnected porous network. Notably, mechanical testing demonstrated an enhancement in compressive strength that was directly correlated with ƒ-MWCNT content, indicating successful load-bearing reinforcement. These findings highlight the synergistic role of nanomaterial reinforcement in developing biomimetic and mechanically robust scaffolds for regenerative medicine.