Preparation, characterization, and in vitro evaluation of bleomycin-containing nanoliposomes

Bleomycin is an anticancer drug used against various types of cancers. The aim of this study was to prepare a new PEGylated and non-PEGylated nanoliposomal formulation of bleomycin (PEG-nLip-BLM and nLip-BLM) and evaluate their anticancer activity in different tumor cell lines. The liposomes were prepared by thin-film hydration method, and then, bleomycin (BLM) was loaded to the prepared vesicles. The size, zeta potential, entrapment efficiency, loading rate, release profile, and cytotoxicity of liposomal formulations in TC-1, LLC1, and HFLF-PI5 cell lines were investigated. Mean particle size and zeta potential of the PEG-nLip-BLM and nLip-BLM were found to be 99.4 ± 4.6 nm and -34.83 ± 4.7 mV; and 112.2 ± 7.2 nm and -27.5 ± 3.2 mV, respectively, which were stable for at least 2 months. Encapsulation and loading efficiency of BLM for PEG-nLip-BLM and nLip-BLM were obtained about 83.1 ± 4.2% and 14.3 ± 2.5%; and 78.3 ± 8.6% and 11.1 ± 3.3%, respectively. Drug release study showed a slow release pattern without considerable burst effect. The liposomal formulations indicated lower toxicity compared to free drug in case of TC-1 and HFLF-PI5 cells, but their cytotoxicity against LLC1 cells was significantly higher than free drug. The results of this study indicated that PEG-nLip-BLM can be a suitable candidate for drug delivery to solid tumors.