Abstract
A novel poly(2-ethyl-2-oxazoline)-block-poly(aspartic acid) (PEOz-b-PAsp) was synthesized and investigated as a potential carrier for the amphotericin B (AmB) delivery in forming polyion complex (PIC) micelles. Nano-scale AmB/PEOz-b-PAsp PIC micelles were prepared by thin film method. The nano-scale PIC micelles with core-shell structure were formed with a hydrophilic outer shell and dissociation of the carboxylic group from PAsp to become a hydrophobic inner core for drug delivery application. The resulting nano-scale PIC micelles with AmB and PEOz-b-PAsp showed an average diameter about 108 nm. The drug content of the PIC micelles can be as high as 47 % in phosphate buffer solution with pH 7.4. The release of AmB from nano-scale PIC micelles was 60 % at 40 h in phosphate buffer solution with pH 7.4. The minimal inhibitory concentration (MIC) of PIC micelles was 20μg/mL, and antifungal activity of PIC micelles was better than Fungizone® during 72 hrs. In conclusion, AmB/PEOz-b-PAsp PIC micelles were developed and optimized for drug delivery to allow efficient antifungal activity with low cytotoxicity. Engineering of biodegradable polymers to form non-covalent drug-polymer interactions of PIC micelles constitutes a useful approach for the future design of drug carriers. Keywords: Amphotericin B, Diblock copolymer, Polyion complex micelle, Drug controlled release, Antifungal activity.