Controlled Release of Dual Antibacterial Drug from Composite Hydrogels

Hydrogels with a controlled release of dual antibacterial drug have been developed to effectively prevent bacterial infections for biomedical applications. The synergistic dual drug aims to fight against drug resistant bacteria, which become more commonly found nowadays. In this study, we fabricated composite hydrogels using calcium carbonate microspheres as drug carriers to load a combination of tetracycline and ampicillin into the matrices for controlled drug release. The composite hydrogels were prepared using three different molar ratios between polymers and crosslinkers to investigate the effect of crosslink density on the physical properties and drug release. The drug release profiles were quantitatively analyzed to compare diffusivity and release mechanism. The results revealed that the crosslinker molar ratio influenced not only the physical properties, but also the drug release rate and mechanism. The different release characteristics of the drugs also suggested chemical interactions between the calcium carbonate microspheres and the small molecules. Such insight could assist designing of composite hydrogels for controlled dual drug release in biomedical applications.