Lucia Montenegro
Department of Drug Sciences, University of Catania, V.le A. Doria 6, 95125 Catania. Italy.
Curr Drug Metab. 2017;18(5):469-480. doi: 10.2174/1389200218666170222152038.
The skin, being the outermost layer of our body, is constantly exposed to oxidative stress induced by UV-radiation, pollutants, smoke and xenobiotics. To counteract the deleterious effects of such exposure, the skin is equipped with a complex anti-oxidation system, involving both exogenous and endogenous antioxidants. As low molecular weight antioxidants undergo depletion in counteracting oxidative stress occurring in the skin, topical supplementation with these agents is regarded as a suitable strategy to restore skin oxidative balance. Unfortunately, most antioxidants show unfavorable physico-chemical properties (e.g. excessive lipophilicity or hydrophilicity, chemical instability) that strongly limit their skin penetration and hence their effectiveness after topical application. To overcome these drawbacks, nanocarriers such as liposomes, niosomes, nanoemulsions and nanoparticles have been widely investigated as dermal delivery systems for antioxidants.
The present paper will review two different types of lipid-based nanocarriers, solid lipid nanoparticles (SLN) and nanostructured lipid carriers (NLC), which represent the latest innovation in the field of nanoparticles designed as topical drug delivery systems. The effects of loading different topical antioxidants into SLN or NLC will be examined along with the usefulness of these antioxidant delivery systems in improving skin defenses against oxidative stress.
In this review, recent studies regarding ability of solid lipid nanoparticles and nanostructured lipid carriers to improve dermal delivery of low molecular weight antioxidants have evidenced that these carriers show technological properties that make them particularly useful for topical delivery of antioxidants, both in pharmaceutical and cosmetic field.
皮肤作为人体最外层，不断受到紫外线辐射、污染物、烟雾和外源性物质诱导的氧化应激影响。为了对抗这种暴露带来的有害影响，皮肤配备了一个复杂的抗氧化系统，包括外源性和内源性抗氧化剂。由于低分子量抗氧化剂在对抗皮肤中发生的氧化应激时会消耗殆尽，局部补充这些物质被认为是恢复皮肤氧化平衡的合适策略。不幸的是，大多数抗氧化剂表现出不利的物理化学性质（如过度亲脂性或亲水性、化学不稳定），这严重限制了它们的皮肤渗透性，从而限制了局部应用后的有效性。为了克服这些缺点，脂质体、非离子脂质体、纳米乳剂和纳米颗粒等纳米载体作为抗氧化剂的皮肤递送系统已得到广泛研究。
本文将综述两种不同类型的脂质基纳米载体，即固体脂质纳米粒（SLN）和纳米结构脂质载体（NLC），它们代表了作为局部药物递送系统设计的纳米颗粒领域的最新创新。将研究将不同的局部抗氧化剂负载到SLN或NLC中的效果，以及这些抗氧化剂递送系统在改善皮肤抗氧化应激防御方面的实用性。
在本综述中，关于固体脂质纳米粒和纳米结构脂质载体改善低分子量抗氧化剂皮肤递送能力的最新研究表明，这些载体具有的技术特性使其在制药和化妆品领域特别适用于局部递送抗氧化剂。
