Preparation, characterization and antioxidative activity analysis of recombinant humanized collagen type III-loaded liposomes

To improve the bioavailability and biological activity of recombinant type III humanized collagen (rhCol III), we optimized the preparation process of recombinant type III humanized collagen-loaded liposomes (rhCol III-LIPS) using the film dispersion and periplasmic extrusion methods, with the encapsulation rate as the response value. Then we analyzed the antioxidative activity of rhCol III-LIPS by determining the scavenging rate of free radicals. We investigated the protective effect of rhCol III-LIPS against H₂O₂-induced injuries in HaCaT cells by detecting cell vitality, contents of reactive oxygen species (ROS), malondialdehyde (MDA), and activities of antioxidases superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase dismutase (GSH-Px). The results showed, in condition of rhCol III-to-lipid ratio of 1:50, membrane-to-material ratio of 4:1, and ultrasound duration of 20 min, the encapsulation rate of the liposome reached 91.89%±0.59%. The free-radical scavenging rates for 1,1-diphenyl-2-picrohydrazine (DPPH), 2,2-l diazo-bisdiamine salt (ABTS), hydroxyl (OH^-), and superoxide (O^2-) anions are 87.11% ± 2.54%, 93.72% ± 2.87%, 86.45% ± 1.62%, 76.67% ± 1.56% respectively. The protective effect on oxidation-damaged cells of rhCol III-LIPS was higher than rhCol III or blank liposomes (B-LIPS). In summary, rhCol III-LIPS has good physical stability and in-vitro antioxidative activity, effectively alleviating H₂O₂-induced oxidative injuries in HaCaT cells. Our study provides a more stable and efficient strategy for the application of rhCol.