Wenhui Wu

Type II Collagen and Gelatin from Silvertip Shark (Carcharhinus albimarginatus) Cartilage: Isolation, Purification, Physicochemical and Antioxidant Properties

Type II acid soluble collagen (CIIA), pepsin soluble collagen (CIIP) and type II gelatin (GII) were isolated from silvertip shark (Carcharhinus albimarginatus) cartilage and examined for their physicochemical and antioxidant properties. GII had a higher hydroxyproline content (173 mg/g) than the collagens and cartilage. CIIA, CIIP and GII were composed of two identical α1 and β chains and were characterized as type II. Amino acid analysis of CIIA, CIIP and GII indicated imino acid contents of 150, 156 and 153 amino acid residues per 1000 residues, respectively. Differing Fourier transform infrared (FTIR) spectra of CIIA, CIIP and GII were observed, which suggested that the isolation process affected the secondary structure and molecular order of collagen, particularly the triple-helical structure. The denaturation temperature of GII (32.5 °C) was higher than that of CIIA and CIIP. The antioxidant activity against 1,1-diphenyl-2-picrylhydrazyl radicals and the reducing power of CIIP was greater than that of CIIA and GII. SEM microstructure of the collagens depicted a porous, fibrillary and multi-layered structure. Accordingly, the physicochemical and antioxidant properties of type II collagens (CIIA, CIIP) and GII isolated from shark cartilage were found to be suitable for biomedical applications.

Pharmacokinetics and tissue distribution of a novel marine fibrinolytic compound in Wistar rat following intravenous administrations

We investigated a novel marine fibrinolytic compound for use in thrombolytic therapy. Pharmacokinetics and the tissue distribution of this novel marine fibrinolytic compound, FGFC1(2) (fungi fibrinolytic compound 1), were investigated in Wistar rats after intravenous (IV) bolus administration of two concentrations (10 and 20mg/kg). Plasma FGFC1 and tissue extracts were measured using HPLC with UV detection. FGFC1 was detected using a C18 column with a gradient eluted mobile phase of acetonitrile-water (0.1% trifluoroacetic acid), 1.0mL/min. Chromatograms were monitored at 265nm (column temperature: 40°C). Pharmacokinetic data indicate that FGFC1 fitted well to a two-compartment model. Elimination half-lives (t1/2) of FGFC1 were 21.51±2.17 and 23.22±2.11min for 10 and 20mg/kg, respectively. AUC0-t were 412.19±19.09, 899.09±35.86μg/mLmin, systemic clearance (CL) was 0.023±0.002, 0.022±0.002 ((mg/kg)/(μg/mL)/min) and the mean residence time (MRT) was 10.15±0.97, 9.65±1.40min at 10 and 20mg/kg, respectively. No significant differences were observed in the systemic clearance and mean residence time at the tested doses, suggesting linear pharmacokinetics in rats. Tissue distribution data reveal that FGFC1 distributed rapidly in most tissues except the brain and that the highest concentration of the drug was in the liver. In the small intestine, FGFC1 initially increased and then declined, but remained comparatively high 60min after administration, suggesting that enterohepatic circulation may exist.

Cross-talk between primary osteocytes and bone marrow macrophages for osteoclastogenesis upon collagen treatment

Homeostasis of osteoclast formation from bone marrow macrophages (BMM) is regulated by paracrine signals of the neighbourhood bone cells particularly mesenchymal stem cells (MSC), osteoblasts and osteocytes (OC). Besides paracrine cues, collagen and glycosaminoglycan are involved in controlling bone homeostasis. Towards this approach, different molecular weight collagens were reacted with MSC, OC and BMM to understand the bone homeostasis activity of collagen. The up-regulating effect of collagens on osteogenic cell growth was confirmed by the presence of mineralized nodules in the osteoblastogenic lineage cells and increased osteogenic stimulatory gene expression. The decreased BMM-derived TRAP+ osteoclasts number and osteoclastogenic regulatory gene expression of OC could demonstrate the exploitive osteoclastogenic activity of collagens. Osteoclastogenesis from BMM was triggered by paracrine cues of OC in some extend, but it was down-regulated by collagen. Overall, the effect of collagen on osteoclastogenesis and osteoblastogenesis may depend on the molecular weight of collagens, and collagen suppresses osteoclastogenesis, at least in part by downregulating the secretion of cytokines in OC.

Evaluation of Differentiated Bone Cells Proliferation by Blue Shark Skin Collagen via Biochemical for Bone Tissue Engineering

Collagen from a marine resource is believed to have more potential activity in bone tissue engineering and their bioactivity depends on biochemical and structural properties. Considering the above concept, pepsin soluble collagen (PSC) and acid soluble collagen (ASC) from blue shark (Prionace glauca) skin were extracted and its biochemical and osteogenic properties were investigated. The hydroxyproline content was higher in PSC than ASC and the purified collagens contained three distinct bands α1, α2, and β dimer. The purity of collagen was confirmed by the RP-HPLC profile and the thermogravimetric data showed a two-step thermal degradation pattern. ASC had a sharp decline in viscosity at 20–30 °C. Scanning electron microscope (SEM) images revealed the fibrillar network structure of collagens. Proliferation rates of the differentiated mouse bone marrow-mesenchymal stem (dMBMS) and differentiated osteoblastic (dMC3T3E1) cells were increased in collagen treated groups rather than the controls and the effect was dose-dependent, which was further supported by higher osteogenic protein and mRNA expression in collagen treated bone cells. Among two collagens, PSC had significantly increased dMBMS cell proliferation and this was materialized through increasing RUNX2 and collagen-I expression in bone cells. Accordingly, the collagens from blue shark skin with excellent biochemical and osteogenic properties could be a suitable biomaterial for therapeutic application.

Lipometabolic Alteration in Mice Feeding Eatable Tissues of Chinese Mitten Crab

Objective: Chinese mitten crab is a famous aquatic species in eastern Asian region, but their edible parts, particularly hepatopancreas and gonads, generally contain very high levels of lipids that may have negative effects on human health. This study investigated the effects of different edible parts of Chinese mitten crab on the body weight and lip metabolism for Kunming mice. Method: The mice were fed with diets containing one part of an Chinese mitten crab or the mixture of parts of an Chinese mitten crab for 4 weeks. There were 9 treatments. The triacylglycerol (TG), total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C) and low density lipoprotein cholesterol (LDL-C) were enzymatically determined using commercial kits (purchased from Nanjing Jiancheng Bioengineering Institute, China). The arteriosclerosis index (AI) was calculated by the equation: AI = (TC – HDL-C)/HDL-C. The levels of fatty acid syntheses (FAS), the 3-hydroxy-3-methyl-glutaryl-coenzyme A reductase (HMG-CoA) and lipoprotein lipase (LPL) were measured using commercially available kits according to the manufacturer’s instructions. The significant differences between the groups were further analyzed by Bonferronis’s t-test. Results: Our results showed that the crab hepatopancreas, gonads and the mixed male crab-edible parts increased blood lipids in some experiment group of mice corresponding to a change in the nutrition-related liver enzymes. It shows that addition of the Chinese mitten crab has an adverse effect on the blood lipid levels in mice. The FFH, FFMI and FMMI groups had significantly higher weight than the FN group (P < 0.05). The crab hepatopancreas, crab gonads and the mixed male crab-edible parts cause an increase in the blood lipid levels. The crab mixture significantly affected the AI value of male and female mice (P < 0.01). The level of FMMI group was significantly higher than the FN group (P < 0.05). Other groups showed no significant difference. The level of the FFMI group was significantly lower than the FN group (P < 0.05), and levels in the MMM and MFMI groups were significantly lower than the MN group (P < 0.05). Conclusion: It clearly showed that long-term feeding with the Chinese mitten crab has an adverse effect on the blood lipid levels in mice. One the one hand, the weight, liver index and fat index of experimental mice were changed than normal mice. On the other hand, the crab diet affects the level of TC, TG, AI and FASN on increasing. It is suggested that the special diet has affected lip metabolic alteration associated with contents of serum lipids and metabolic enzymes. But according to a certain regular feeding, there would be no adverse effect on mice. On the contrary, it may adjust the blood lipid in mice