Cinnamon leaf oil release from chitosan microcapsules embedded within a sodium alginate-gelatin hydrogel-like film for the inhibition of multi-drug resistant bacteria

[Excerpt] Pseudomonas aeruginosa is considered a public threat, with a great number of antibiotic resistant microorganisms. Essential oils (EOs) have demonstrated significant effects against several pathogens, however, they present a volatile nature, therefore, biodegradable polymeric delivery platforms are being engineered. Here, hydrogel-like films were produced from a combination of sodium alginate (SA) and gelatin (GN) to serve as delivery platforms for the controlled release of cinnamon leaf oil (CLO) entrapped within chitosan (CS) microcapsules. CS microcapsules were prepared via ionotropic gelation with tripolyphosphate (TPP), with CLO at minimum inhibitory concentration (MIC) in the core. Microcapsules were then embedded within a biodegradable SA/GN polymeric matrix processed via a solvent casting/phase inversion methodology with SA/GN used at 70/30 polymer ratio and 2 wt% SA concentration in distilled water. The coagulation bath was composed of a 2 wt% calcium chloride (CaCl2 ) aqueous solution. Qualitative and quantitative antimicrobial examinations validated the modified film potential to fight infections caused by P. aeruginosa bacteria.