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The purpose of this study is to develop a new type of nanodrug delivery material by modifying milk polar lipid (MPL) liposomes with the S-layer protein. LIP-RLSFNP (MPL liposomes encapsulating RLSFNP (Arg-Leu-Ser-Phe-Asn-Pro)) and SLP-LIP-RLSFNP (S-layer protein-modified LIP-RLSFNP) were prepared and characterized by transmission electron microscopy, Fourier transform infrared spectroscopy, confocal laser scanning microscopy, surface plasmon resonance, and mastersizer dynamic light scattering measurements. The results showed that the S-layer protein could modify the surface of MPL liposomes, stabilize the shape of the vesicles, and improve the resistance to external interference. Furthermore, SLP-LIP-RLSFNP showed better performance in in vitro and in vivo experiments compared with LIP-RLSFNP in terms of promoting absorption and delayed release. The findings suggested that MPL liposomes modified with the S-layer protein have potential for use as an effective delivery system for therapeutic proteins and peptides.

Fruiting bodies that exhibit strong autolysis of Coprinopsis cinerea are a good resource for the chitinolytic system. In this study, a new Chitinase ChiE1 from C. cinerea was cloned, heterologously expressed, and characterized. Biochemical analysis demonstrated that ChiE1 is an exochitinase with a processive mode of action. Although ChiE1 contains only a single catalytic domain without a binding domain, it can bind to and degrade insoluble chitin powder and colloidal chitin. The combination of ChiE1 and C. cinerea endochitinase ChiIII could increase the amount of reducing sugar released from chitin powder by approximately 120% compared to using ChiE1 and ChiIII alone. The synergistic action of ChiE1 and ChiIII on degradation of chitin powder is higher than all previously reported synergism of chitinases. The recombinant Chitinase ChiE1 expressed in Pichia pastoris may be used as a synergistic chitinase for a reconstituted chitinolytic system for agricultural, biological, and environmental applications.

The effect of lotus leaf ( Nelumbo nucifera Gaertn.) on diabetes is unclear. We hypothesized that lotus leaf can regulate insulin secretion and blood glucose levels. The in vitro and in vivo effects of lotus leaf methanolic extract (NNE) on insulin secretion and hyperglycemia were investigated. NNE increased insulin secretion from β cells (HIT-T15) and human islets. NNE enhanced the intracellular calcium levels in β cells. NNE could also enhance phosphorylation of extracellular signal-regulated protein kinases (ERK)1/2 and protein kinase C (PKC), which could be reversed by a PKC inhibitor. The in vivo studies showed that NNE possesses the ability to regulate blood glucose levels in fasted normal mice and high-fat-diet-induced diabetic mice. Furthermore, the in vitro and in vivo effects of the active constituents of NNE, quercetin, and catechin, on glucose-induced insulin secretion and blood glucose regulation were evaluated. Quercetin did not affect insulin secretion, but catechin significantly and dose-dependently enhanced insulin secretion. Orally administered catechin significantly reversed the glucose intolerance in high-fat-diet-induced diabetic mice. These findings suggest that NNE and its active constituent catechin are useful in the control of hyperglycemia in non-insulin-dependent diabetes mellitus through their action as insulin secretagogues.