One-pot synthesis and characterization of crosslinked polyphosphazene dopamine microspheres for controlled drug delivery applications

Abstract

Inorganic–organic hybrid and highly cross-linked poly(cyclotriphosphazene-co-dopamine) microspheres (PCTD) were successfully synthesized by a one-step precipitation polymerization technique. In the polymerization reaction, dopamine (a neurotransmitter), hexachlorocyclotriphosphazene (HCCP, N₃P₃Cl₆) and triethylamine (TEA) were used as a monomer, a crosslinker molecule and an acid acceptor, respectively. The characterization of PCTD microspheres was performed by SEM-EDX, FTIR, XRD, TGA and DLS. The particle size of microspheres were determined as 1.042 µm. The usability of synthesized novel polyphosphazene microspheres for controlled drug release was investigated using acriflavine as a model drug. Acriflavine has antimicrobial and anticancer properties. As drug release medium pH:7.4 (PBS) and pH: 5.0 buffer solutions were used. They were the pH of blood and the approximate pH of the environment in which the cancerous cells are located, respectively. PCTD microspheres have 19.5 mgg⁻¹ drug storage capacity and 29% (pH: 5.0) and 47% (pH: 7.4) of the acriflavine was released from PCTD microspheres at 37 °C during 7 days.

Keywords:

• Dopamine
• hexachlorocyclotriphosphazene
• controlled drug release
• precipitation polymerization
• polyphosphazene microspheres