Min Mildred, Egli Caitlin, Bartolome Rebecca Alonzo, Sivamani Raja K
Integrative Skin Science and Research Sacramento, Sacramento, CA, USA.
College of Medicine, California Northstate University, Elk Grove, CA, USA.
Clin Cosmet Investig Dermatol. 2024 Jun 21;17:1481-1494. doi: 10.2147/CCID.S461753. eCollection 2024.
The topical application of antioxidants has been shown to augment the skin's innate antioxidant system and enhance photoprotection. A challenge of topical antioxidant formulation is stability and penetrability. The use of a targeted drug delivery system may improve the bioavailability and delivery of antioxidants. In this ex vivo study, we assessed the effects of the topical application of a liposome-encapsulated antioxidant complex versus a free antioxidant complex alone on skin photoaging parameters and penetrability in human skin explants.
Human organotypic skin explant cultures (hOSEC) were irradiated to mimic photoaging. The encapsulated antioxidant complex and free antioxidant complex were applied topically onto the irradiated hOSEC daily for 7 days. The two control groups were healthy untreated hOSEC and irradiated hOSEC. Photoprotective efficacy was measured with pro-inflammatory cytokine (IL-6 and IL-8) and matrix metalloproteinase 9 (MMP-9) secretion. Cell viability and metabolic activity were measured via resazurin assay. Tissue damage was evaluated via lactate dehydrogenase (LDH) cytotoxicity assay. Skin penetration of the encapsulated antioxidant complex was assessed via fluorescent dye and confocal microscopy.
Compared to healthy skin, irradiated skin experienced increases in IL-6, IL-8 (p < 0.05), and MMP-9 (p < 0.05) secretion. After treatment with the encapsulated antioxidant complex, there was a 39.3% reduction in IL-6 secretion, 49.8% reduction in IL-8 (p < 0.05), and 38.5% reduction in MMP-9 (p < 0.05). After treatment with the free antioxidant complex, there were no significant differences in IL-6, IL-8, or MMP-9 secretion. Neither treatment group experienced significant LDH leakage or reductions in metabolic activity. Liposomes passed through the stratum corneum and into the epidermis.
The topical application of a liposome-encapsulated antioxidant complex containing ectoin, astaxanthin-rich microalgae extract, and THDA improves penetrability and restored IL-6, IL-8, and MMP-9 levels in irradiated human skin explants, which was not seen in the comparator free antioxidant complex group.
局部应用抗氧化剂已被证明可增强皮肤的天然抗氧化系统并增强光保护作用。局部抗氧化剂配方面临的挑战是稳定性和渗透性。使用靶向药物递送系统可能会提高抗氧化剂的生物利用度和递送效果。在这项体外研究中，我们评估了局部应用脂质体包裹的抗氧化剂复合物与单独的游离抗氧化剂复合物对人皮肤外植体皮肤光老化参数和渗透性的影响。
对人器官型皮肤外植体培养物（hOSEC）进行辐照以模拟光老化。将包裹的抗氧化剂复合物和游离抗氧化剂复合物每天局部应用于辐照后的hOSEC上，持续7天。两个对照组分别是未处理的健康hOSEC和辐照后的hOSEC。通过促炎细胞因子（IL-6和IL-8）和基质金属蛋白酶9（MMP-9）的分泌来测量光保护效果。通过刃天青测定法测量细胞活力和代谢活性。通过乳酸脱氢酶（LDH）细胞毒性测定法评估组织损伤。通过荧光染料和共聚焦显微镜评估包裹的抗氧化剂复合物的皮肤渗透性。
与健康皮肤相比，辐照后的皮肤IL-6、IL-8（p < 0.05）和MMP-9（p < 0.05）的分泌增加。用包裹的抗氧化剂复合物处理后，IL-6分泌减少39.3%，IL-8分泌减少49.8%（p < 0.05），MMP-9分泌减少38.5%（p < 0.05）。用游离抗氧化剂复合物处理后，IL-6、IL-8或MMP-9的分泌没有显著差异。两个处理组均未出现明显的LDH泄漏或代谢活性降低。脂质体穿过角质层进入表皮。
局部应用含有依克多因、富含虾青素的微藻提取物和THDA的脂质体包裹的抗氧化剂复合物可提高渗透性，并恢复辐照后人皮肤外植体中IL-6、IL-8和MMP-9的水平，而在比较的游离抗氧化剂复合物组中未观察到这种情况。
