PEGylated liposomes as an emerging therapeutic platform for oral nanomedicine in cancer therapy: in vitro and in vivo assessment

Abstract

In the rapidly expanding field of nanomedicine, liposomes have been considered as the most successful drug carrier having various clinically approved products. However, their delivery via oral route has been a persistent challenge due to harsh environment of the gastrointestinal tract. Herein, we explored the potential of PEGylation onto liposomes as an effective strategy to protect them from harsh gastric environment and as a successful drug delivery carrier for oral drug delivery. Conventional and PEGylated liposomes loaded with exemestane (EXE) were prepared, characterized and freeze-dried in the presence of trehalose to enhance their long-term stability. In addition, their stability in the simulated gastric fluid (SGF, pH 1.2) was carried and found that the PEGylation successfully protected the liposomes from acidic degradation compared to conventional liposomes. Intracellular uptake and Ex vivo gut permeation studies demonstrated that the PEGylated liposomes were better internalized into the cells and higher permeated through the intestine. In vivo, PEGylated liposomes depicted a notable enhancement in the oral bioavailability of EXE in contrast to conventional liposomes and EXE suspension. Our results provide a new insight for the successful delivery of poorly soluble and poorly permeable drugs via PEGylated liposomes to enhance the medical performance of an oral nanomedicine.