Preparation of macro-, micro-, and nano-sized poly(Tannic acid) particles with controllable degradability and multiple biomedical uses

Abstract

Different size ranges of poly(Tannic acid) (p(TA)) particles, 2000–500 μm, 500–200 μm, 200–20 μm, and 20–0.5 μm, were successfully synthesized by using lecithin/gasoline microemulsion media. Macro, micro, and nano sized p(TA) particles were crosslinked via poly(ethylene glycol) diglycidyl ether (PEGGE) with 85 ± 7% gravimetric yield. The hydrolytic degradation of different sizes of p(TA) particles in physiological pH conditions, in pH 5.4, 7.4, and 9.0 buffer solutions at 37.5 °C, were investigated. It was found that p(TA) particles with 20–0.5 μm size distribution are more stable than the other sized particles due to the higher amounts of crosslinker used during synthesis. Furthermore, macro size p(TA) particles (2000–500 μm) were totally degraded at pH 9 within 12 days, whereas a linear and sustained degradation profile was obtained at pH 7.4 with 75 ± 4% weight loss for 24 days. The antioxidant capacity of p(TA) particles was also tested and 20–0.5 μm sized p(TA) particles demonstrated the highest antioxidant capacity with 0.1305 ± 0.0124 mg gallic acid equivalency and 145 ± 21 mM trolox equivalent g−1. It was also further demonstrated that the degraded p(TA) particles showed high antimicrobial activity against a wide spectrum of bacteria and yeast strains such as Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, and Candida albicans. In vitro blood compatibility of p(TA) particles was also examined by hemolysis % and blood clotting index and micrometer sized p(TA) particles are more hemocompatible with enhanced blood clotting capability. In addition, WST-1 cytotoxicity test results showed that 200–20 μm and 20–0.5 μm sized p(TA) particles were biocompatible up to 50 μg/mL concentration with 74 ± 3 and 68 ± 2% cell viabilities for L929 fibroblast cells.