Formulation and evaluation of a two-stage targeted liposome coated with hyaluronic acid for improving lung cancer chemotherapy and overcoming multidrug resistance

Multidrug resistance (MDR) has emerged as a prominent challenge contributing to the ineffectiveness of chemotherapy in treating non-small cell lung cancer (NSCLC) patients. Currently, mitochondria of cancer cells are identified as a promising target for overcoming MDR due to their crucial role in intrinsic apoptosis pathway and energy supply centers. Here, a two-stage targeted liposome (HA/TT LP/PTX) was successfully developed via a two-step process: PTX-loaded cationic liposome (TT LP/PTX) were formulated by lipid film hydration & ultrasound technique, followed by further coating with natural anionic polysaccharide hyaluronic acid (HA). TT, an amphipathic polymer conjugate of triphenylphosphine (TPP)-tocopheryl polyethylene glycol succinate (TPGS), was used to modify the liposomes for mitochondrial targeting. The average particle size, zeta potential and encapsulation efficiency (EE%) of HA/TT LP/PTX were found to be 153 nm, -30.3 mV and 92.1% based on the optimal prescription of HA/TT LP/PTX. Compared to cationic liposome, HA-coated liposomes showed improved stability and safety, including biological stability in serum, cytocompatibility, and lower hemolysis percentage. In drug-resistant A549/T cells, HA was shown to improve the cellular uptake of PTX through CD44 receptor-mediated endocytosis and subsequent degradation by hyaluronidase (HAase) in endosomes. Following this, the exposure of TT polymer facilitated the accumulation of PTX within the mitochondria. As a result, the function of mitochondria in A549/T cells was disturbed, leading to an increased ROS level, decreased ATP level, dissipated MMP, and increased G2/M phase arrest. This resulted in a higher apoptotic rate and stronger anticancer efficacy.