TONI ANDOR CIGU, MIHAELA NICOLETA HOLBAN, ANCA NICULINA CADINOIU, VALERIU SUNEL, CATALINA LIONTE, MARCEL POPA, JACQUES DESBRIERES, CORINA CHEPTEA POLYELECTROLYTE COMPLEX BASED NANOCAPSULES CARRYING NOVEL 5-NITROINDAZOLE THIAZOLIDINES WITH POTENTIAL USE IN TREATING ORAL INFECTIONS The aim of this research was the synthesis of novel 2,3-disubstituted 1,3 thiazolidines, derived from 5-nitroindazole with antimicrobial activity and their encapsulation into polymer nanocapsules. Starting from previously synthesised hydrazones, there have been obtained novel thiazolidines by reaction with thioglycolic acid. The envisaged chemical structures were confirmed by spectral and elemental analysis. Two of the obtained thiazolidines were encapsulated into cationic Eudragit E100 nanocapsules, obtained by nanoprecipitation. In order to enhance drug release characteristics and particle stability, Eudragit E100 nanocapsules were covered with anionic polysaccharide (sodium alginate), thus forming a complex polyelectrolyte based membrane. The obtained nanocapsules presented a slower and more controlled drug release. The synthesized active principles, in free state and encapsulated into polymer nanocapsules, were tested for their acute toxicity and their influence on the development of model bacterial strains (Staphylococcus mutans, Actinobacillus actinomycetemcomitans, Bacillus subtilis, Bacillus cereus, Salmonella enteritidis, Escherichia coli and Staphylococcus aureus).