Jin-Ye Wang

Charge influence of liposome on transdermal delivery efficacy

To investigate the charge influence of the drug delivery system, cholesterol analogues, either with cationic, 4-cholesterocarbonyl-4′-(N,N,N-triethylamine butyloxyl bromide) azobenzene (CAB), or the neutral, 4-cholesterocarbonyl-4′-(N,N-diethylamine butyloxyl) azobenzene (ACB) were synthesized and combined in liposomal membranes respectively. CdTe quantum dots (QDs) were loaded into the vesicles as the fluorescence probe to trace the transdermal delivery processing on the nude mouse dorsal skin. Cellular uptake of QDs by NIH 3T3 cells was also studied. The result showed that the cationic liposome facilitated the internalization of loaded QDs into cells and distributed in cytoplasm area within a 1 h incubation. Moreover, in contrast to neutrally charged liposomes, the cationic liposome promoted transdermal delivery of loaded QDs through the skin. In 2 h, cationic liposomes delivered QDs to the upper epidermis, whereas QDs in neutrally charged liposomes still remained on the skin surface which had no obvious facilitation. The retentions of neutrally charged liposome loaded QDs in the epidermis after 8 h, were similar to the naked QDs which were used as control. On the other hand, although in low amounts, the cationic liposomes delivered QDs into vascular dermis at 12 h, helped the diffusion of QDs to the dermal layer.

Two azobenzene derivatives CAB/ACB as reusable sunscreen: UV absorptive capacity and biosafety evaluation

Exposure to UV radiation may cause harmful effects to the skin such as damage, aging and cancer, which can be prevented by using sunscreens. Here, two azobenzene derivatives, 4-cholesterocarbonyl-4′-(N,N,N-triethylaminebutyloxyl bromide) azobenzene (CAB) and 4-cholesterocarbonyl-4′-(N,N-diethylaminebutyloxyl) azobenzene (ACB) were studied as reusable sunscreen candidates. Biocompatibility studies including apoptosis, cytotoxicity and in vivo phototoxicity revealed that the two compounds were rather safe, except ACB, which showed a weak phototoxicity in vitro. Both CAB and ACB have good UV absorption capacity not only in their solution state (dimethylsulfoxide, DMSO) but also in the cosmetic cream state. A commercial sunscreen, avobenzone was decomposed upon UV irradiation and lost its UV protection ability, while that of CAB and ACB could be quickly recovered upon visible light irradiation, implying that they can serve as a new type of reusable sunscreen.

Chemiluminescence imaging of UVA induced reactive oxygen species in mouse skin using L-012 as a probe

Abstract Reactive oxygen species (ROS) caused by ultraviolet A (UVA) can be reduced by treating with antioxidants and photoprotective reagents. Here we reported a real-time chemiluminescence (CL) imaging method which was simple, non-invasive and sensitive to evaluate UVA-induced ROS generation and the efficacy of sunscreens and antioxidants in vivo. The in vitro experiments indicated that l-ascorbic acid, live SPSC01 yeast, and its intracellular metabolites can suppress the intensity of CL signals in the presence of hydrogen peroxide, which proved the good antioxidant ability of them. Meanwhile, we used 8-amino-5-chloro-7-phenylpyrido[3,4-d] pyridazine-1,4(2H,3H) dione (L-012) as a high sensitive CL probe for in vivo imaging of ROS generated by UVA irradiation. The CL intensity was reduced after treated with l-ascorbic acid and SPSC01 yeast intracellular metabolites, consistent with the in vitro results. Additionally, the in vivo protective capability of two azobenzene compounds as sunscreens was confirmed further through the suppression of CL signals of UVA-induced ROS in mouse skin by this method.