de Brum Tainá L, Fiel Luana A, Contri Renata V, Guterres Sílvia S, Pohlmann Adriana R
J Nanosci Nanotechnol. 2015 Jan;15(1):773-80. doi: 10.1166/jnn.2015.9185.
Biodegradable nanoparticles have been widely studied as drug carriers in order to increase drug solubility in aqueous media, modify biodistribution, target tissues and organs or control the drug release. Those nanoparticles are, in general, produced as liquid formulations to act as final dosage forms or as intermediate for solid or semi-solid products. Considering the dermatological applications, as medicines or cosmetics, different nanoparticles have been proposed to control the skin penetration of encapsulated lipophilic substances. A point rarely investigated is the penetration of the carrier itself into the skin, independent of the drug penetration profile. In this way, our objective was to correlate the flexibility of the biodegradable nanoparticles to the depth of their skin penetration. To minimize the impact of the chemical composition, the surface chemistry or the shape and size distribution on the results, two kinds of polymeric nanocapsules presenting diverse mechanical properties were produced using almost the same materials and their concentrations. The nanocapsules (NC) and the lipid-core nanocapsules (LNC) were prepared by solvent displacement using Rhodamine B-labeled polymer, oil and surfactants. The only difference in composition between them is the presence of sorbitan monostearate in the latter which was used to have a more rigid nanoparticle as previously reported. NC and LNC had, respectively, mean diameters of 178 and 180 nm and zeta potentials of -11 and -9 mV. The in vitro skin penetration was carried out using Franz cells (pig skin as membrane). Skin samples were observed by confocal laser scanning microscopy (CLSM). NC reached the dermis, while LNC was retained at the outermost layers of the skin. The result was in accordance with the flexibility previously determined for those nanocapsules, in a way that higher flexibility gives deeper penetration. NC can reach the dermis and LNC can act as reservoir systems at the epidermis.
可生物降解纳米颗粒作为药物载体已得到广泛研究，目的是提高药物在水性介质中的溶解度、改变生物分布、靶向组织和器官或控制药物释放。这些纳米颗粒通常制成液体制剂，用作最终剂型或作为固体或半固体产品的中间体。考虑到在皮肤病学方面的应用，作为药物或化妆品，人们提出了不同的纳米颗粒来控制被包裹的亲脂性物质的皮肤渗透。一个很少被研究的点是载体本身渗透到皮肤中的情况，与药物的渗透情况无关。通过这种方式，我们的目标是将可生物降解纳米颗粒的柔韧性与其皮肤渗透深度相关联。为了最小化化学成分、表面化学或形状和尺寸分布对结果的影响，使用几乎相同的材料及其浓度制备了两种具有不同机械性能的聚合物纳米胶囊。纳米胶囊（NC）和脂质核纳米胶囊（LNC）通过使用罗丹明B标记的聚合物、油和表面活性剂的溶剂置换法制备。它们之间唯一的成分差异是后者中存在单硬脂酸山梨醇酯，如先前报道的那样，该物质用于制备更刚性的纳米颗粒。NC和LNC的平均直径分别为178和180 nm，zeta电位分别为-11和-9 mV。使用Franz细胞（猪皮作为膜）进行体外皮肤渗透实验。通过共聚焦激光扫描显微镜（CLSM）观察皮肤样本。NC到达了真皮层，而LNC则保留在皮肤的最外层。该结果与先前确定的那些纳米胶囊的柔韧性一致，即柔韧性越高，渗透越深。NC可以到达真皮层，而LNC可以在表皮层充当储库系统。
