Work

Host-guest Encapsulation of Photosensitizer to Construct Antibacterial Silicone Rubber: Enhanced Homogeneity and Dual-action

Year: 2026

Type: preprint

Abstract: An efficient process for the construction of antibacterial silicone rubber by a combined action of multiple quaternary ammonium salts (QAS) functionalities and photodynamic process through host-guest encapsulation of photosensitizer Rose Bengal (RB) into amphiphilic hyperbranched quaternary ammonium salts (Am-HQAS) nanocapsules was developed. RB is incompatible with silicone rubber, but the host-guest complexation between RB and Am-HQAS could make RB homogenously dispersed in silicone rubber matrix and wash-resistant. When the amphiphilic HQAS was incorporated into silicone rubber through tertiary amino group-initiated epoxy ring-opening reaction, the modified silicone rubber samples, RTV-Am x series, could reach an antibacterial efficacy of 94% and 96% for Escherichia coli ( E. coli ) and Staphylococcus aureus ( S. aureus ), respectively. Efficacy was found to increase with increasing quaternization degree of the embedded Am-HQAS. After encapsulating RB, the resulted e-RTV-Am 60 -RB sample could release singlet oxygen 1 O 2 under LED light irradiation and the killing rate after light irradiation increased to 98% and 99% for E. coli and S. aureus , respectively. The e-RTV-Am 60 sample exhibited a yield strength of 0.73 MPa and a compressive modulus of 25 MPa, much larger than that of raw silicone rubber. A negligible change of comprehensive strength after multiple loading-unloading cycles suggested excellent elasticity and shape recovery ability. The excellent mechanical strength and high antibacterial efficacy could render the presented materials interesting for healthy and medical applications. Besides, it is believed that other hydrophilic photosensitizers are also applicable to this host-guest system.

Source: Research Square

DOI: 10.21203/rs.3.rs-10578588/v1