Biological activities of chitosan and prepared chitosan-tripolyphosphate nanoparticles using ionic gelation method against various pathogenic bacteria and fungi strains

Abstract

Chitosan is a cationic natural polymer which has been widely used in various areas. Present study focused on the preparation of the chitosan nanoparticles (NPs) throughout ionic gelation method and using tripolyphosphate (TPP), as non-toxic polyanion counter-ions. Chitosan NPs solutions were prepared by mixing of the 10 mL chitosan solutions, with different concentrations (1, 2 and 3 mg/mL), and different amounts of the TPP (4, 6, 8, 10, 12, 14 mL) at 35 °C. Physico-chemical characteristics of prepared chitosan NPs solutions were evaluated using FT-IR, DLS, TEM and UV-Vis spectroscopy. Achieved results indicated that optimum conditions to prepare opalescent chitosan NPs suspension achieved by using 10 mL of chitosan solution (3 mg/mL) and 14 mL TPP. The provided chitosan NPs at these conditions had highest turbidity (0.317 a.u.) and zeta potential (+15.9 mV) values. The formed spherical chitosan NPs in the solution had minimum mean particle size of 20 nm. Antibacterial activities analysis against both Gram positive and negative bacteria strains indicated that the formed chitosan NPs had higher bactericidal effects as compared to the chitosan solution. Obtained results also revealed that both chitosan solution (3 mg/mL) and its prepared NPs had strong fungicidal activity against Aspergillus flavus.