γ-聚谷氨酸防晒纳米粒子的制备及性能

Preparation and properties of γ-polyglutamic acid-based sunscreen nanoparticles

摘要:

以天然大分子γ-聚谷氨酸（γ-PGA）为原料，使用疏水小分子L-苯丙氨酸乙酯（L-phe）对其进行改性得到双亲大分子，通过大分子自组装的方法负载阿伏苯宗（AVB）、甲氧基肉桂酸异辛酯（OMC）和二苯甲酮-3（BP-3）三种有机防晒剂得到γ-PGA防晒纳米粒子，并对其光稳定性、广谱防晒性、皮肤渗透性和细胞毒性进行了研究。结果表明：紫外辐照后，与未负载的有机防晒剂组合物相比，γ-PGA防晒纳米粒子在UVA范围的吸光度下降程度从12%降低至3%，在UVB范围的吸光度下降程度从18%降低至4%，光稳定性得到了提升。同时，制备的防晒纳米粒子在整个紫外波段具有广谱防晒性、低皮肤渗透性和低细胞毒性。将该防晒纳米粒子应用于防晒霜配方中，当添加量为配方总质量的10%时，防晒霜防晒指数（SPF）可达75。

Abstract:

An amphiphilic macromolecule was first synthesized by conjugation of hydrophobic small molecule L-phenylalanine ethyl ester (L-phe) to the natural macromolecule γ-polyglutamic acid (γ-PGA). Avobenzone (AVB), isooctyl methoxycinnamate (OMC) and benzophenone-3 (BP-3) as organic sunscreen agents were then loaded into the γ-PGA nanoparticles through the macromolecular self-assembly for the preparation of sunscreen nanoparticles. The photostability, broad-spectrum sunscreen properties, skin permeability and cytotoxicity of these γ-PGA-based sunscreen nanoparticles were characterized. Compared with the unloaded organic sunscreen composition, the decrease in UVA absorbance of γ-PGA sunscreen nanoparticles was reduced from 12% to 3%, and decreased from 18% to 4% in UVB absorbance after UV irradiation, which proved the photostability improvement. At the same time, the γ-PGA sunscreen nanoparticles have broad-spectrum sun protection in the entire ultraviolet band and low skin permeability and low cytotoxicity. Moreover, the γ-PGA sunscreen nanoparticles were used as sunscreen agent in a typical sunscreen formulation, and the sun protection factors (SPF) of the sunscreen can reach to 75 at the 10% mass fraction loading.