Vrouvaki Ilianna, Koutra Eleni, Kornaros Michael, Avgoustakis Konstantinos, Lamari Fotini N, Hatziantoniou Sophia
Laboratory of Pharmaceutical Technology, Department of Pharmacy, University of Patras, 26504 Patras, Greece.
Laboratory of Biochemical Engineering and Environmental Technology (LBEET), Department of Chemical Engineering, University of Patras, 26504 Patras, Greece.
Pharmaceutics. 2020 Apr 14;12(4):353. doi: 10.3390/pharmaceutics12040353.
Polymeric nanoparticles (NPs) encapsulating L. var. essential oil (EO) were prepared by a solvent evaporation method, in order to obtain a novel carrier for administration on the skin. The specific EO exhibits antimicrobial and anti-inflammatory properties thus stimulating considerable interest as a novel agent for the treatment of minor skin inflammations. The incorporation into nanoparticles could overcome the administration limitations that inserts the nature of the EO. Nanoparticles were prepared, utilizing poly(lactic acid) (PLA) as shell material, due to its biocompatibility and biodegradability, while the influence of surfactant type on NPs properties was examined. Two surfactants were selected, namely poly(vinyl alcohol) (PVA) and lecithin (LEC) and NPs' physicochemical characteristics i.e. size, polydispersity index (PdI) and ζ-potential were determined, not indicating significant differences ( > 0.05) between PLA/PVA-NPs (239.9 nm, 0.081, -29.1 mV) and PLA/LEC-NPs (286.1 nm, 0.167, -34.5 mV). However, encapsulation efficiency (%EE) measured by GC-MS, was clearly higher for PLA/PVA-NPs than PLA/LEC-NPs (37.45% vs. 9.15%, respectively). Moreover PLA/PVA-NPs remained stable over a period of 60 days. The in vitro release study indicated gradual release of the EO from PLA/PVA-NPs and more immediate from PLA/LEC-NPs. The above findings, in addition to the SEM images of the particles propose a potential structure of nanocapsules for PLA/PVA-NPs, where shell material is mainly consisted of PLA, enclosing the EO in the core. However, this does not seem to be the case for PLA/LEC-NPs, as the results indicated low EO content, rapid release and a considerable percentage of humidity detected by SEM. Furthermore, the Minimum Inhibitory Concentration (MIC) of the EO was determined against and , while NPs, however did not exhibit considerable activity in the concentration range applied. In conclusion, the surfactant selection may modify the release of EO incorporated in NPs for topical application allowing its action without interfering to the physiological skin microbiota.
采用溶剂蒸发法制备了包封薰衣草变种精油（EO）的聚合物纳米颗粒（NPs），以获得一种用于皮肤给药的新型载体。该特定的EO具有抗菌和抗炎特性，因此作为治疗轻度皮肤炎症的新型药物引起了极大的兴趣。将其包封到纳米颗粒中可以克服由于EO的性质而导致的给药限制。由于聚乳酸（PLA）具有生物相容性和生物降解性，因此选用PLA作为壳材料来制备纳米颗粒，同时研究了表面活性剂类型对NPs性质的影响。选择了两种表面活性剂，即聚乙烯醇（PVA）和卵磷脂（LEC），并测定了NPs的物理化学特性，即尺寸、多分散指数（PdI）和ζ电位，结果表明PLA/PVA-NPs（239.9 nm，0.081，-29.1 mV）和PLA/LEC-NPs（286.1 nm，0.167，-34.5 mV）之间没有显著差异（>0.05）。然而，通过气相色谱-质谱联用（GC-MS）测定的包封效率（%EE），PLA/PVA-NPs明显高于PLA/LEC-NPs（分别为37.45%和9.15%）。此外，PLA/PVA-NPs在60天内保持稳定。体外释放研究表明，EO从PLA/PVA-NPs中逐渐释放，而从PLA/LEC-NPs中释放得更快。上述发现，除了颗粒的扫描电子显微镜（SEM）图像外，还提出了PLA/PVA-NPs纳米胶囊的潜在结构，其中壳材料主要由PLA组成，将EO包裹在核心中。然而，对于PLA/LEC-NPs似乎并非如此，因为结果表明EO含量低、释放快且通过SEM检测到相当比例的湿度。此外，还测定了EO对[具体菌种1]和[具体菌种2]的最低抑菌浓度（MIC），然而，NPs在所应用的浓度范围内没有表现出显著活性。总之，表面活性剂的选择可能会改变用于局部应用的NPs中EO的释放，使其发挥作用而不干扰皮肤生理微生物群。
