Design and in vitro antibiofilm activity of propolis diffusion-controlled biopolymers

In this study, a novel pH-sensitive hydrogel beads that is based on gelatin/sodium alginate/chitosan (GEL/SA/CS) loaded with propolis ethanolic extracts (PE) were synthesized. The swelling behavior of GEL/SA/CS hydrogel beads was studied in different pH solutions and compared with unloaded CS (GEL/SA) hydrogel beads. The in vitro release studies have been revealed using four different pH (1.3, 5.0, 6.0, and 6.8), a saliva environment (pH 6.8), a simulated gastric fluid (SGF) (pH 1.3), and a simulated intestinal fluid (SIF) (pH 6.8) to simulate the physiological conditions in gastrointestinal (GI) tract. Propolis-loaded hydrogel beads were found to be stable at pH 1.3, 5.0, 6.0, simulated saliva, SGF, and SIF mediums, whereas the beads lose their stability at pH 6.8 buffer solution. Tested microorganisms displayed greater sensitivity to PE-loaded hydrogel beads compared with pure propolis. Contrary to antimicrobial activity results, antibiofilm activity results of PE-loaded GEL/SA and GEL/SA/CS hydrogel beads were found at low levels. According to the obtained results, the propolis-loaded GEL/SA/CS hydrogel beads synthesized within this study can be used in the treatment of GI tract diseases such as oral mucositis, gastric ulcer, ulcerative colitis, and GI cancer, as controlled releasing carriers of propolis.