State Key Laboratory for Pollution Control, School of Environmental Science and Engineering, Tongji University, Shanghai 200092, China.
State Key Laboratory of Dairy Biotechnology, Shanghai Engineering Research Center of Dairy Biotechnology, Dairy Research Institute, Bright Dairy & Food Co., Ltd, Synergetic Innovation Center of Food Safety and Nutrition, Shanghai 200436, China.
Food Res Int. 2020 Nov;137:109380. doi: 10.1016/j.foodres.2020.109380. Epub 2020 Jun 4.
Beta-galactosidase (β-gal), catalyzing the transformation of lactose to glucose and galactose, had been encapsulated in β-chitosan nanoparticles (β-CS NPs) in previous work, but they were prone to aggregation and disscociation, resulting in poor bioavailability of β-gal. Herein, we developed cellulose nanocrystals (CNC, as stabilizers and fillers) stabilized β-gal loaded low molecular weight (LMW) β-CS NPs through ionic gelation technology to enhance enzyme activity and further control in vitro release of β-gal. Results showed that particle size and Zeta potential (ZP) of CNCs stabilized β-gal loaded CS NPs were 143.20 nm and -34.70 mV under the optimal conditions, respectively. Structural analysis were employed to study the incorporation of β-gal and CNC into β-CS NPs. In vitro release study conducted at pH 4.5 and 7.4 showed that both β-gal loaded β-CS NPs and CNC stabilized ones retained the release of β-gal for over 12 h. Moreover, CNC stabilized β-gal loaded β-CS NPs retained higher β-gal activity (81.23%) than that of controls (30%) within 2 h. Therefore, it was indicated that CNC incorporated β-CS NPs could serve as non-toxic and effective carriers of β-gal for the treatment of lactose intolerance.
β-半乳糖苷酶（β-gal）能够催化乳糖转化为葡萄糖和半乳糖，先前的研究已经将其包封于β-壳聚糖纳米粒子（β-CS NPs）中，但是它们容易聚集和解离，导致β-gal 的生物利用度较差。在本研究中，我们通过离子凝胶化技术，利用纤维素纳米晶体（CNC，作为稳定剂和填充剂）稳定负载β-半乳糖酶的低分子量（LMW）β-CS NPs，以提高酶活性并进一步控制β-半乳糖酶的体外释放。结果表明，在最佳条件下，CNC 稳定的负载β-半乳糖酶的 CS NPs 的粒径和 Zeta 电位（ZP）分别为 143.20nm 和-34.70mV。结构分析用于研究β-半乳糖酶和 CNC 掺入β-CS NPs 中。在 pH 4.5 和 7.4 下进行的体外释放研究表明，负载β-半乳糖酶的 CS NPs 和 CNC 稳定的负载β-半乳糖酶的 CS NPs 均能在超过 12h 内保留β-半乳糖酶的释放。此外，在 2h 内，CNC 稳定的负载β-半乳糖酶的 CS NPs 保留了更高的β-半乳糖酶活性（81.23%），而对照（30%）则较低。因此，研究结果表明，CNC 掺入的β-CS NPs 可以作为治疗乳糖不耐受的非毒性和有效的β-半乳糖酶载体。
