A fluorescence correlation spectroscopy (FCS) study on polymer micelles loaded in alumina nanopores for drug delivery applications

Abstract

Polymeric micelles are known for their prominent ability to favourably accumulate at solid tumours by the enhanced permeability and retention (EPR) effect, enabling a targeted drug delivery. In this work, PEGylated phospholipid and basic polymeric micelles (15 to 22 nm) were chosen as lipid-based carriers for poorly soluble drugs. Coumarin 6, a lipophilic fluorescent dye was used as the model drug and encapsulated into PEG micelles. Micelles were loaded in highly ordered, uniform porous alumina, prepared by electrochemical anodisation of aluminium which acted as drug release platforms. The loading and release micelles of fluorescently labelled micelles was studied using fluorescent correlation spectroscopy (FCS), confocal microscopy, thermogravimetry (TG) and scanning electron microscopy (SEM). It was found that loading levels lie in the range 24 to 27 wt %, depending on the micelle type and their release spans from 7 to 20 days. Our results confirm the considerable potential of using micelles for drug delivery in porous implants.