Study on the stability and H+ permeable membrane properties of polymersomes / 药学实践杂志

ABSTRACT

Objective To prepare polymersomes (PSs) by block copolymers，evaluate their membrane structural stability，investigate the H+ transmembrane permeability of PSs and the impact of 1,4-dioxane and establish a foundation for drug encapsulation within polymersomes. Methods PSs were self-assembled by a block copolymer, PEG-PLGA, in a solvent solution. The pH-sensitive fluorescence probe HPTS was employed to examine the H+ transmembrane properties of PSs and compare them with PSs prepared using PBD-b-PEO, PS-b-PEO, and liposomes. The effect of varying concentrations of 1,4-dioxane on PSs’ membrane permeability properties was also investigated. Results The fluorescence excitation spectra of HPTS exhibited pH dependency, which showed a linear correlation between extravesicular H+ concentration and t1/2. Significant differences were observed in the membrane permeability capabilities of PSs with different membrane wall thicknesses. Compared to liposomes, the H+ transmembrane coefficients for the three types of PSs were reduced by 2.39×104, 3.38×104, and 5.48×108 times, respectively. 1,4-dioxane was found to modulate the permeability of PSs’ membranes, which displayed a concentration-dependent relationship. Conclusion PSs exhibited significantly lower membrane permeability compared to liposomes, indicating superior stability. 1,4-dioxane was identified as a modulator of PSs’ permeability, which offered potential for drug loading and release within PSs.