Preparation, characterization, and properties of lutein block polyethylene glycol copolymer loading with lutein nanoparticles

Peng Liu,Xiaoyu Bai,Xingtong Gao,Kai Liu,Aixiang Li,Zijian Lyu,Qiuhong Li 한국고분자학회 2023 Macromolecular Research Vol.31 No.3

In this paper, lutein block polyethylene glycol (lutein-b-PEG) copolymers were synthesized by hydrophilic modification of lutein with carboxylated polyethylene glycol (CT-PEG). The unreacted lutein was loaded into micelles formed by self-assembly of block copolymers to prepare composite nanoparticles. The results of FT-IR, 1H NMR, gel permeation chromatography (GPC), UV–vis and critical micellar concentration (CMC) showed that the double terminal carboxyl group ratio of CT-PEG reached 50.31%, and lutein-b-PEG was successfully synthesized without destroying the structure of lutein. Compared with lutein, the retention rate of lutein composite nanoparticles increased from 4.32 to 81.3% after 30 days of storage in the dark. In addition, the saturation solubility and bioaccessibility of lutein nanoparticles were increased 35 times and 5.2 times, respectively, due to micellar formation and improved water solubility. These findings indicated that the lutein composite nanoparticles modified with PEG significantly improved the chemical stability, water solubility, and bioaccessibility of lutein.

Effects of Temperature and Additives on the Thermal Stability of Glucoamylase from Aspergillus niger

( Yang Liu ),( Zhaoli Meng ),( Ruilin Shi ),( Le Zhan ),( Wei Hu ),( Hongyu Xiang ),( Qiuhong Xie ) 한국미생물 · 생명공학회 2015 Journal of microbiology and biotechnology Vol.25 No.1

GAM-1 and GAM-2, two themostable glucoamylases from Aspergillus niger B-30, possess different molecular masses, glycosylation, and thermal stability. In the present study, the effects of additives on the thermal inactivation of GAM-1 and GAM-2 were investigated. The half-lives of GAM-1 and GAM-2 at 70ºC were 45 and 216 min, respectively. Data obtained from fluorescence spectroscopy, circular dichroism spectroscopy, UV absorption spectroscopy, and dynamic light scattering demonstrated that during the thermal inactivation progress, combined with the loss of the helical structure and a majority of the tertiary structure, tryptophan residues were partially exposed and further led to glucoamylases aggregating. The thermal stability of GAM-1 and GAM-2 was largely improved in the presence of sorbitol and trehalose. Results from spectroscopy and Native-PAGE confirmed that sorbitol and trehalose maintained the native state of glucoamylases and prevented their thermal aggregation. The loss of hydrophobic bonding and helical structure was responsible for the decrease of glucoamylase activity. Additionally, sorbitol and trehalose significantly increased the substrate affinity and catalytic efficiency of the two glucoamylases. Our results display an insight into the thermal inactivation of glucoamylases and provide an important base for industrial applications of the thermally stable glucoamylases.

Fabrication of Aligned PI/GO Nanofibers for Battery Separators

Qiong Tian,Qiuhong Liu,Kedong Song,Yufan Mei,Jinfeng Peng,Jinfeng Peng,Ji Zhou,Yanhuai Ding 한국섬유공학회 2021 Fibers and polymers Vol.22 No.1

Highly aligned polyimide/graphene oxide (PI/GO) nanofibers were fabricated by using the electrospinning method. As a separator for Li-ion batteries, the PI/GO nanofibers show excellent thermal stability, good wettability toward organicliquid electrolytes and superior electrochemical performance compared to raw PI and commercial battery separators. TheGO nanosheets not only greatly enhance the mechanical strength of the PI matrix, but also increase the resistance to Lidendrites.

Advances in plant-derived natural products for antitumor immunotherapy

Yi Yang,Qinying Liu,Xianai Shi,Qiuhong Zheng,Li Chen,Yang Sun 대한약학회 2021 Archives of Pharmacal Research Vol.44 No.11

In recent years, immunotherapy has emergedas a novel antitumor strategy in addition to traditional surgery,radiotherapy and chemotherapy. It uniquely focuses onimmune cells and immunomodulators in the tumor microenvironmentand helps eliminate tumors at the root by rebuildingthe immune system. Despite remarkable breakthroughs,cancer immunotherapy still faces many challenges: lack ofpredictable and prognostic biomarkers, adverse side eff ects,acquired treatment resistance, high costs, etc. Therefore,more effi cacious and effi cient, safer and cheaper antitumorimmunomodulatory drugs have become an urgent requirement. For decades, plant-derived natural products obtainedfrom land and sea have provided the most important sourcefor the development of antitumor drugs. Currently, moreattention is being paid to the discovery of potential cancerimmunotherapy modulators from plant-derived naturalproducts, such as polysaccharides, phenols, terpenoids, quinonesand alkaloids. Some of these agents have outstandingadvantages of multitargeting and low side eff ects and lowcost compared to conventional immunotherapeutic agents.

Preparation and Performance Study of COS/PEI@PolyI:C/OVA Nanocomposite Using the Blend System of Chitooligosaccharide and Polyethyleneimine as a Drug Carrier

Kai Zhang,Qian Sun,Xiaoyu Bai,Peng Liu,Zijian Lyu,Qiuhong Li,Aixiang Li 한국고분자학회 2021 Macromolecular Research Vol.29 No.11

The blending system of chitooligosaccharide (COS) and polyethyleneimine (PEI) was studied as a drug carrier for tumor treatment. Nanoparticles COS/ PEI-PolyI:C-OVA-x (CP-P-O-x) (x=1, 2, 3) were prepared by electrostatic self-assembly of COS and PEI with the immune enhancing drug PolyI:C and the mimic antigen ovalbumin (OVA) using different feeding methods. The results showed that the nanoparticle solution could be stable only when the concentration of the added PEI was above 5.0% w/w. PolyI:C could be coated well and protected from nuclease degradation. The OVA encapsulation efficiency was above 75%. The results of cell viability experiments showed that the blend of COS and PEI had low cytotoxicity. The CP-P-O-1 had a suitable particle size, which was easy to be absorbed and expressed by cells. The results of in vitro immunization showed that due to the addition of PolyI:C, whether OVA was loaded on the inside or on the surface, nanoparticles significantly promoted the secretion of cytokines mouse tumor necrosis factor α (TNF-α) and mouse interferon-γ (IFN-γ). The feeding method mainly had a greater impact on the morphology and size of the nanoparticles, and had little effect on solution stability, OVA encapsulation efficiency, binding ability with PolyI:C, resistance to nuclease degradation and immune performance. CP-P-O-x prepared by the blend system of COS and PEI will be a potential candidate for tumor treatment.

The Effects of Glucagon-like Peptide-2 on the Tight Junction and Barrier Function in IPEC-J2 Cells through Phosphatidylinositol 3-kinase-Protein Kinase B-Mammalian Target of Rapamycin Signaling Pathway

Yu, Changsong,Jia, Gang,Deng, Qiuhong,Zhao, Hua,Chen, Xiaoling,Liu, Guangmang,Wang, Kangning Asian Australasian Association of Animal Productio 2016 Animal Bioscience Vol.29 No.5

Glucagon-like peptide-2 (GLP-2) is important for intestinal barrier function and regulation of tight junction (TJ) proteins, but the intracellular mechanisms of action remain undefined. The purpose of this research was to determine the protective effect of GLP-2 mediated TJ and transepithelial electrical resistance (TER) in lipopolysaccharide (LPS) stressed IPEC-J2 cells and to test the hypothesis that GLP-2 regulate TJ and TER through the phosphatidylinositol 3-kinase (PI3K)-protein kinase B (Akt)-mammalian target of rapamycin (mTOR) signaling pathway in IPEC-J2 cells. Wortmannin and LY294002 are specific inhibitors of PI3K. The results showed that $100{\mu}g/mL$ LPS stress decreased TER and TJ proteins occludin, claudin-1 and zonula occludens protein 1 (ZO-1) mRNA, proteins expressions (p<0.01) respectively. GLP-2 (100 nmol/L) promote TER and TJ proteins occludin, claudin-1, and zo-1 mRNA, proteins expressions in LPS stressed and normal IPEC-J2 cells (p<0.01) respectively. In normal cells, both wortmannin and LY294002, PI3K inhibitors, prevented the mRNA and protein expressions of Akt and mTOR increase induced by GLP-2 (p<0.01) following with the significant decreasing of occludin, claudin-1, ZO-1 mRNA and proteins expressions and TER (p<0.01). In conclusion, these results indicated that GLP-2 can promote TJ's expression and TER in LPS stressed and normal IPEC-J2 cells and GLP-2 could regulate TJ and TER through the PI3K/Akt/mTOR pathway.

Expression and Characterization of a Single-Chain Variable Fragment against Human LOX-1 in Escherichia coli and Brevibacillus choshinensis

( Wei Hu ),( Jun-yan Xiang ),( Ping Kong ),( Ling Liu ),( Qiuhong Xie ),( Hongyu Xiang ) 한국미생물 · 생명공학회 2017 Journal of microbiology and biotechnology Vol.27 No.5

The single-chain variable fragment (scFv) against lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1) is a promising molecule for its potential use in the diagnosis and immunotherapy of atherosclerosis. Producing this scFv in several milligram amounts could be the starting point for further engineering and application of the scFv. In this study, the abundant expression of the anti-LOX-1 scFv was attempted using Escherichia coli (E. coli) and Brevibacillus choshinensis (B. choshinensis). The scFv had limited soluble yield in E. coli, but it was efficiently secreted by B. choshinensis. The optimized fermentation was determined using the Plackett-Burman screening design and response surface methodology, under which the yield reached up to 1.5 g/l in a 5-L fermentor. Moreover, the properties of the scFvs obtained from the two expression systems were different. The antigen affinity, transition temperature, and particle diameter size were 1.01E-07 M, 55.2 ± 0.3℃, and 9.388 nm for the scFv expressed by B. choshinensis, and 4.53E-07 M, 52.5 ± 0.3℃, and 13.54 nm for the scFv expressed by E. coli. This study established an efficient scale-up production methodology for the anti-LOX-1 scFv, which will boost its use in LOX-1-based therapy.