制备一种包埋木瓜蛋白酶生物膜材料并应用于美白护肤品

Preparation of a papain-embedding biological membrane material and its application in the skin-whitening products

木瓜蛋白酶是一种清除老化皮肤,祛除黑色素的天然巯基蛋白酶,具有美白嫩肤的功效。这种酶制剂需要保存在合适的温度、湿度、p H条件下,极容易在化妆品加工过程因为操作不当损失酶活力。通过聚丙烯酰胺(PAM)凝胶包埋的方法,成功地制备了一种水溶性强、酶活力高的木瓜蛋白酶生物膜。扫描电镜分析发现,当铝离子浓度为1.2 mol/L、铝离子加入量为500μL、反应时间为10 h时,木瓜蛋白酶生物膜交联结构最为理想。用制备所得生物膜做成美白护肤品,该化妆品的酶活力是同质量浓度木瓜蛋白酶化妆品的3倍,表明该生物膜结构有效保护了化妆品中的酶活性。在研究木瓜蛋白酶生物膜与保湿剂复配稳定性实验中,发现小分子保湿剂不会影响包埋酶生物膜的结构。通过进行生物膜与乳化剂复配实验,结果表明生物膜中的聚丙烯酰胺会与乳化剂发生包裹聚沉反应,从而破坏生物膜包埋酶的稳定结构。基于上述研究,表明木瓜蛋白酶生物膜适用于含小分子保湿剂的水性化妆品配方体系。

Papain is a natural sulfhydryl protease of removing aging skin and eliminating melanin, which has skin whitening and skin rejuvenation effects. This enzyme needs to be stored at appropriate temperature, humidity and pH, otherwise it will easy lose its activity during cosmetics processing because of improper operation. Compared with free enzyme, immobilized enzyme can maintain its high efficiency and specific catalytic activity. The commonly used methods of immobilization are cross-linking and embedding. Polyacrylamide( PAM) is a linear water-soluble macromolecule with good biocompatibility and harmless to skin without irritation. It is suitable for cosmetics and commonly used as cosmetics thickener. By PAM gel embedding method, a kind of papain biological membrane with good stability and high enzyme activity could be successfully synthesized. The SEM results showed that the optimal cross-linked structure of the biological membrane was obtained when the concentration and addition amount of aluminum ions was 1.2 mol/L, and 500 μL, and the reaction time was 10 h. It is found that the enzyme activity of the skin-whitening cosmetics containing this kind of biomaterial is three times higher than that of the enzyme-containing cosmetics because of the protection from PAM gel. However, the enzyme activity in the formula of cosmetics containing biological membrane was not as good as that of biological membrane, so the influencing factors of biological membrane stability need further study. It was found that small-molecule moisturizers such as glycerine, propanediol, carbamide and sorbitol did not affect the structure of the biological membrane with embedded enzyme. The sodium hyaluronate with high molecular weight could intertwine with the PAM, making the papain-embedding biological membrane wrap more tightly, resulting in a reduced contact area between the enzyme and the substrate. It was found that PAM would interact with the emulsifiers like Tween20, Tween60, Tween80, APG0814 or M68 and induce encapsulation and sedimentation, thus destroying the stable structure of the enzyme embedded in biological membrane. It is concluded that papain-embedding biological membrane is suitable for the formulation of water-based cosmetics containing small-molecule moisturizers.