Abstract

Lipase cartridges are currently the mainstay of treatment to improve fat absorption related to pancreatic insufficiency (PI) in patients receiving enteral nutrition feedings. Enzyme immobilization is an essential prerequisite for designing lipase cartridges systems for efficient enzymatic fat hydrolysis. A microfluidic approach has been adopted to produce lipase (LIP) caged in hyperbranched polyglycerol microcapsules (HPGly). The resulting HPGly-LIP microcapsules are spherical and had an average diameter of 29 µm with monomodal size distribution. The optimum conditions determined by artificial neural networks were HPGly concentration of 10 wt.%, LIP loading of 20% (wt) and total flow rate in microfluidic cell of 1.0 mL/h. Under these conditions, the maximum capacity of the LIP that can be microencapsulated is around 85% with respect to the HPGly concentration of 10 wt.% and total flow rate in microfluidic cell of 1.0 mL/h. This resultant HPGly-LIP exhibited Michaelis–Menten coefficients of 1.138,14 mM (K_m) and 0.49 U/mg (V_max) showing higher activity compared to free LIP. Finally, the robust HPGly-LIP microcapsules showed excellent recyclability. The in vitro Analysis of the HPGly-LIP cytotoxicity showed that microcapsules had no cytotoxic effect to L929 fibroblasts cells and behaved very similar to the negative control. These features will be useful for the facile construction of biocatalytic systems with high efficiency, excellent recyclability and adequate biocompatibility for treatment of patients with PI receiving enteral nutrition feedings.

摘要

脂肪酶药筒目前是改善接受肠内营养喂养患者与胰腺功能不全 (PI) 相关的脂肪吸收的主要治疗方法。酶固定化是设计用于高效酶促脂肪水解的脂肪酶筒系统的必要先决条件。已采用微流控方法来生产封闭在超支化聚甘油微胶囊 (HPGly) 中的脂肪酶 (LIP)。所得 HPGly-LIP 微胶囊为球形，平均直径为 29 µm，具有单峰尺寸分布。人工神经网络确定的最佳条件是HPGly 浓度为10 wt.%、LIP 负载为20% (wt) 和微流控单元中的总流速为1.0 mL/h。在这些条件下，相对于 10 wt.% 的 HPGly 浓度和 1.0 mL/h 的微流控单元中的总流速，可微囊化的 LIP 的最大容量约为 85%。所得 HPGly-LIP 的 Michaelis-Menten 系数为 1.138,14 mM (K _m ) 和 0.49 U/mg ( V _max ) 与游离 LIP 相比显示出更高的活性。最后，坚固的 HPGly-LIP 微胶囊表现出出色的可回收性。HPGly-LIP 细胞毒性的体外分析表明，微胶囊对 L929 成纤维细胞没有细胞毒性作用，其行为与阴性对照非常相似。这些特征将有助于轻松构建具有高效率、优异可回收性和足够生物相容性的生物催化系统，用于治疗接受肠内营养喂养的 PI 患者。