One step synthesis of an amino acid derived particles, poly( L‐Arginine ) and its biomedical application

Herein, single step synthesis of poly(L-Arginine) (p(L-Arg)) particles was reported for the first time via microemulsion crosslinking method using tetrakis(hydroxymethyl) phosphonium chloride (THPC) as the crosslinking agent. The C-P vibrational FT-IR peaks of the p(L-Arg) particles observed at 1035 cm−1 as well as elemental analysis results corroborated the successful crosslinking of native L-Arg molecules with THCP. Spherical-shaped p(L-Arg) particles visualized by SEM analysis ranged 1–10 μm in size in dry state. The important parameters of p(L-Arg) particles affecting their biomedical potential use such as degradability, blood compatibility, antioxidant and antimicrobial properties were thoroughly investigated. Accordingly, 49.2 ± 6.7%, 68.1 ± 4.8%, and 62.5 ± 7.1% of the p(L-Arg) particles were degraded at pH 5.4, 7.4, and 9.0, respectively, in about 200 h. The p(L-Arg) particles exhibited fascinating blood compatibility with less than 4% hemolysis induction and more than 95% blood clotting index at 2 mg/mL concentration. The antioxidant activity of p(L-Arg) particles was measured as 0.66 ± 0.06 μM Trolox equivalent g−1 by means of TEAC assay. Moreover, the antimicrobial activity of L-Arg amino acid against Escherichia coli ATCC 8739, Pseudomonas aeruginosa ATCC 10145, gram-positive Staphylococcus aureus ATCC 6538, B. subtilis ATCC 6633 bacteria, and Candida albicans ATCC 10231 yeast strains was significantly enhanced in the form of p(L-Arg) particles. Furthermore, drug loading and release performances of p(L-Arg) particles were also investigated using naproxen and riboflavin as active pharmaceuticals. Based on drug release studies performed in PBS at pH 7.4, 73.9 ± 12.6% of loaded naproxen was released in 90 min, whereas 62.1 ± 4.6% of loaded riboflavin was released in 135 min.