Background: Oxidative stress, propelled by reactive oxygen species (ROS), serves as a significant catalyst for atherosclerosis (AS), a primary contributor to vascular diseases on a global scale. Antioxidant therapy via nanomedicine has emerged as a pivotal approach in AS treatment. Nonetheless, challenges such as inadequate targeting, subpar biocompatibility, and limited antioxidant effectiveness have restrained the widespread utilization of nanomedicines in AS treatment. This study aimed to synthesize a specialized peptide-modified liposome capable of encapsulating two antioxidant enzymes, intending to enhance targeted antioxidant therapy for AS.
Methods: The film dispersion method was employed for liposome preparation. Fluorescence quantification was conducted to assess the drug encapsulation rate. Characterization of liposome particle size was performed using dynamic light scattering (DLS) and transmission electron microscopy (TEM). Laser confocal microscopy and flow cytometry were utilized to analyze liposome cell uptake and target foam cells. Antioxidant analysis was conducted using 2',7'-Dichlorodihydrofluorescein diacetate (DCFH-DA) staining, while pro-lipid efflux analysis utilized Oil Red O (ORO) staining. Safety evaluation was performed using Hematoxylin and Eosin (H&E) staining. The level of inflammatory factors was determined through enzyme-linked immunosorbent assay (ELISA). The degree of lipid oxidation at the cellular level was assessed using the malonaldehyde (MDA) assay. In vivo targeting analysis was conducted using small animal live imaging.
Results: Our in vitro and in vivo findings substantiated that the modification of Lyp-1 led to increased delivery of antioxidant enzymes into foam cells (p < 0.05), the primary pathological cells within AS plaques. Upon accumulation in foam cells, liposomes loaded with superoxide dismutase (SOD) and catalase (CAT) (LyP-lip@SOD/CAT) effectively mitigated excess ROS and shielded macrophages from ROS-induced damage (p < 0.01). Furthermore, the reduction in ROS levels notably hindered the endocytosis of oxidized low-density lipoprotein (Ox-LDL) by activated macrophages, subsequently alleviating lipid accumulation at atherosclerotic lesion sites, evident from both in vitro and in vivo ORO staining results (p < 0.01). LyP-lip@SOD/CAT significantly curbed the secretion of inflammatory factors at the plaque site (p < 0.001). Additionally, LyP-lip@SOD/CAT demonstrated commendable biological safety.
Conclusions: In this study, we effectively synthesized LyP-lip@SOD/CAT and established its efficacy as a straightforward and promising nano-agent for antioxidant therapy targeting atherosclerosis.
Keywords: LyP-1; SOD/CAT; antioxidant; atherosclerosis; liposome.