Chitosan-nanohydroxyapatite composites: mechanical, thermal and bio-compatibility studies

Area of Science:

• Biomaterials Science
• Materials Engineering
• Nanotechnology

Background:

• Chitosan-based materials are widely explored for biomedical applications due to their biocompatibility and biodegradability.
• Developing advanced bone substitutes requires materials with mechanical properties mimicking native bone and excellent bioactivity.

Purpose of the Study:

• To synthesize and characterize chitosan/nanohydroxyapatite (nHA) bionanocomposites using 2-hydroxyethyl methacrylate (HEMA) as a coupling agent.
• To evaluate the mechanical performance, interfacial adhesion, cytocompatibility, and in vitro bioactivity of the developed bionanocomposites for bone tissue engineering.

Main Methods:

• Bionanocomposites were fabricated using chitosan, nanohydroxyapatite (nHA), and 2-hydroxyethyl methacrylate (HEMA).
• Mechanical properties (tensile, flexural, compressive) were assessed at varying nHA loadings.
• Micromechanical theories were employed to analyze interfacial adhesion.
• Cytocompatibility was evaluated through cell culture studies.
• In vitro bioactivity was assessed by soaking the composites in simulated body fluid (SBF).

Main Results:

• Optimal tensile and flexural properties were observed at 8% nHA loading.
• Compressive modulus significantly increased from 525.16 MPa (0% nHA) to 1326.5 MPa with 10% nHA.
• HEMA coupling agent and filler functionalization enhanced mechanical properties, approaching those of human bone.
• Micromechanical analysis indicated good interfacial adhesion between the chitosan matrix and nHA fillers.
• Composites demonstrated cytocompatibility and induced multiple layers of apatite formation in SBF.

Conclusions:

• The developed chitosan/nHA bionanocomposites, particularly with HEMA functionalization, exhibit significantly enhanced mechanical properties and bioactivity.
• The observed bone-like mechanical characteristics and apatite-forming ability suggest their high potential as effective bone substitute materials for orthopedic and dental applications.