Selenized liposomes with ameliorative stability that achieve sustained release of emodin but fail in bioavailability

Stability of liposomes plays a crucial role in drug delivery, especially in oral aspect. The structural modification of liposomes has been the orientation of efforts to improve their stability and enable the controllability of payload release. This study reported a selenylation strategy to optimize the liposomal structure in an attempt to enhance the nanocarrier's stability, hence the bioavailability of emodin (EM), an active compound with poor water-solubility. EM-loaded selenized liposomes (EM-Se@LPs) were prepared by thin film dispersion followed by in situ reduction technique. The results showed that EM-Se@LPs were provided with enhancive gastrointestinal stability and exhibited sustained release of drug compared with EM-loaded liposomes (EM-LPs). However, the modified liposomes with Se depositing onto the interior and exterior bilayers did not substantially facilitate absorption of EM. The reinforced structure of liposomes irrelevant to absorption was affirmed to be due to good stability and absorbability of EM itself. Nevertheless, the present work provides an alternative option for stabilization of liposomes instead of conventional methods, which may be promising for oral delivery of physiologically unstable and/or poorly absorbed drugs and systemic drug delivery.