Linolenic acid-modified methoxy poly (ethylene glycol)-oligochitosan conjugate micelles for encapsulation of amphotericin B

Introduction of linolenic acid (LNA) and methoxy poly (ethylene glycol) (MPEG) to the backbone of oligochitosan (CS) afforded LNA-modified MPEG-CS conjugate (MPEG-CS-LNA). Amphotericin B-loaded MPEG-CS-LNA micelles (AmB-M) were prepared via dialysis method with 82.27 +/- 1.96% of drug encapsulation efficiency and 10.52 +/- 0.22% of drug loading capacity. The AmB-M enhanced AmB's water-solubility to 1.64 mg/mL, being 1640-folds higher than native AmB. The AmB-M obviously reduced hemolytic effect and renal toxicity of AmB when compared to marketed AmB injection (AmB-I). Its antifungal activity against Candida albicans was equivalent to AmB-I although AmB's release from AmB-M was significantly retarded. According to fluorescence microscopy test, the unchanged activity should be attributed to enhanced fungal cellular uptake of AmB-M caused by combined inducement of LNA and CS. The pharmacokinetic studies demonstrated that AmB-M also improved the pharmacokinetic parameters of AmB with AmB-I as control. Conclusively, developed LNA-modified MPEG-CS micellar system could be a viable alternative to the current toxic commercial AmB-I as a highly efficacious drug delivery system.