Citric Acid Cross-Linked Gelatin-Based Composites with Improved Microhardness.

Area of Science:

• Biomaterials Science
• Materials Engineering
• Dental Materials

Background:

• Gelatin is a promising biopolymer for biomedical applications.
• Enhancing gelatin's mechanical properties and biocompatibility is crucial for its use in dentistry.
• Cross-linking and reinforcement are key strategies to improve composite performance.

Purpose of the Study:

• To investigate the impact of citric acid cross-linking and calcium phosphate reinforcements (β-tricalcium phosphate and hydroxyapatite) on gelatin's physico-mechanical properties.
• To evaluate the structural, thermal, and mechanical characteristics of novel hybrid composites.
• To assess the biocompatibility of the developed materials.

Main Methods:

• Preparation of gelatin type B (GB) composites cross-linked with citric acid (CA).
• Incorporation of β-tricalcium phosphate (β-TCP) and hydroxyapatite (HAp) particles into the GB-CA matrix to form hybrid composites.
• Characterization using Fourier-transform infrared spectroscopy (FTIR), morphological investigation, and microindentation testing.
• Cytotoxicity assessment using MTT assay on L929 cells.

Main Results:

• FTIR confirmed no chemical interaction between reinforcements and the gelatin matrix, indicating particles did not affect CA cross-linking.
• Morphological studies showed citric acid cross-linking improved particle dispersion, enhancing mechanical performance.
• Microindentation revealed significant increases in hardness (up to 449%) and reduced modulus of elasticity (up to 288%).
• MTT assay demonstrated that the hybrid composite (GB-TCP-HA-CA) was non-cytotoxic.

Conclusions:

• Gelatin cross-linked with citric acid and reinforced with β-TCP and HAp exhibits superior mechanical properties.
• The developed hybrid composites are non-cytotoxic and show potential for use in dental applications.
• This novel composite material offers a promising alternative for regenerative dentistry and tissue engineering.