Sponges containing tetracycline loaded-PLGA-zein microparticles as a periodontal controlled release device

Abstract

This paper aimed to design collagen sponges containing tetracycline-loaded PLGA-zein microparticles with controlled release characteristics as an alternative for periodontal treatment. Tetracycline microparticles were prepared by spray-drying technique, while the sponges were prepared by their dispersion in collagen suspension and subsequent freeze-drying. Release studies of two microparticles compositions loaded and unloaded-collagen sponges were carried over a 10 days period. Antibiogram tests were used to ensure the sustained antibacterial activity against Staphylococcus aureus. SEM imagens demonstrated spherical and non-aggregated microparticles (2–5 μm) and their effective dispersion within the sponges, what together with the pronounced water sorption promoted by the collagen fibers enhanced the drug release from the unitary particles. The dissolution profiles showed a sustained-release pattern for both sponges and microparticles formulations, reaching in some cases almost the complete drug recovery. The sponge formulations increased the release of tetracycline up to 45 and 60% in the first 12 h, while their microparticles pairs released less than 30 and 10%, respectively, as a result of their aggregation. Antibiograms showed that the sponges sustained released tetracycline over 10 days and could represent an alternative for periodontal insertion as well as for those applications where the prevention and control of bacterial infections is needed. The incorporation of tetracycline microparticles to collagen sponges improved the release rates of this antimicrobial agent and therefore represents an alternative for controlled antimicrobial activity.