Development of a silicone rubber nanocomposite for prosthetic socket liners with enhanced mechanical and antibacterial properties

Abstract

Due to its ease of processing and excellent thermal and chemical stability, silicone rubber (SR) has become the preferred material for prosthetic socket liners. However, its inherent mechanical weaknesses and low surface free energy challenge durability and adhesion strength. This study aims to improve the mechanical strength, hydrophilic characteristics, and antibacterial effectiveness of silicone rubber used for prosthetic socket liners by optimising the composite formulation that incorporates hydroxyapatite (HA), zinc oxide (ZnO) nanoparticles, and chlorophyll into a silicone rubber matrix. Significant improvements in silicone rubber’s hydrophilicity are attained by incorporating chlorophyll, thus enhancing water absorption capacity. Adding nano-ZnO and nano-HA influences mechanical properties, with aggregation affecting tensile and tear strength. Optimum chlorophyll content is established at 10%, balancing mechanical robustness and water absorption for high-performance denture linings. The composite’s crystalline structure is confirmed by XRD analysis, revealing the presence of ZnO and HA nanoparticles dispersed within the matrix. Antibacterial tests demonstrate significant inhibition against Staphylococcus aureus and Escherichia coli after 24 h of contact. The study successfully formulates a multifunctional nanocomposite with improved performance over conventional silicone, offering the potential for enhanced prosthetic socket viability and infection prevention.