Wu Wenhui

Rheological, biocompatibility and osteogenesis assessment of fish collagen scaffold for bone tissue engineering

In the present investigation, an attempt was made to find an alternative to mammalian collagen with better osteogenesis ability. Three types of collagen scaffolds - collagen, collagen-chitosan (CCH), and collagen-hydroxyapatite (CHA) - were prepared from the cartilage of Blue shark and investigated for their physico-functional and mechanical properties in relation to biocompatibility and osteogenesis. CCH scaffold was superior with pH 4.5-4.9 and viscosity 9.7-10.9cP. Notably, addition of chitosan and HA (hydroxyapatite) improved the stiffness (11-23MPa) and degradation rate but lowered the water binding capacity and porosity of the scaffold. Interestingly, CCH scaffolds remained for 3days before complete in-vitro biodegradation. The decreased amount of viable T-cells and higher level of FAS/APO-1 were substantiated the biocompatibility properties of prepared collagen scaffolds. Osteogenesis study revealed that the addition of CH and HA in both fish and mammalian collagen scaffolds could efficiently promote osteoblast cell formation. The ALP activity was significantly high in CHA scaffold-treated osteoblast cells, which suggests an enhanced bone-healing process. Therefore, the present study concludes that the composite scaffolds prepared from fish collagen with higher stiffness, lower biodegradation rate, better biocompatible, and osteogenesis properties were suitable biomaterial for a bone tissue engineering application as an alternative to mammalian collagen scaffolds.

Pharmacological effects of a recombinant hPTH(1−34) derived peptide on ovariectomized rats

&NA; A recombinant peptide Pro‐Pro‐[Arg11]hPTH(1−34)‐Pro‐Pro, was designed, biosynthesized, and purified in our lab (generated by substituting Arg for Leu at position 11 and adding ‐Pro‐Pro to the carboxyl terminus of hPTH(1−34)‐peptide), and reported to be capable of enhancing serum calcium level in chicken. In this investigation, we studied its impact on the structure, component, and biomechanical properties of rat bones. The pharmacological effect of Pro‐Pro‐[Arg11]hPTH(1−34)‐Pro‐Pro was investigated to evaluate its therapeutic potential for the treatment of osteoporosis, one of the most prevalent and rapidly spreading diseases in the world. 3‐month‐old normal female rats were sham‐ovariectomized or ovariectomized, then fed for 14 weeks. Small doses of Pro‐Pro‐[Arg11]hPTH(1−34)‐Pro‐Pro were given to the rats afterward (daily subcutaneous injection of 0.4–0.9 nmol/100 g body weight for 16 weeks). Values of various parameters, including the body weight, the bone mass, the bone geometry, the bone biomechanics, the bone histology, the bone histomorphology, and the serum biochemistry, were collected before or after animal sacrifice. Daily subcutaneous injection of Pro‐Pro‐[Arg11]hPTH(1−34)‐Pro‐Pro induced 37.0–42.4% increase in vertebral BMD, 28.5–47.9% increase in femoral BMD, 30.7–43.7% decrease in marrow cavity or increase in trabecular bone area. The peptide also increased calcium, phosphorus, and collagen in bone by 52.1–59.7%, 24.5–34.7%, and 26.3–28.0%, respectively. In terms of mechanic properties, peptide administration elevated bone rigidity by 55.7–84.5%, decreased the deflection by 14.8–26.7%, and improved modulus of elasticity by 28.1–76.4%. These data suggest Pro‐Pro‐[Arg11]hPTH(1−34)‐Pro‐Pro has a positive effect on bone mass accumulation and microstructure improvement, fortifies bone strength, and possesses anti‐aging capability, which may merit further investigation.

Novel metabolites from Trichoderma atroviride against human prostate cancer cells and their inhibitory effect on Helicobacter pylori and Shigella toxin producing Escherichia coli

The present study aimed to purify and identify the metabolites from T. atroviride using high-performance liquid chromatography (HPLC) and 1H and 13C nuclear magnetic resonance spectrometer (NMR) followed by analyzing their toxicological, antibacterial and anticancer properties. This work identified two metabolites - TM1 and TM2. TM1 was in two forms: (i) 1, 3-dione-5, 5-dimethylcyclohexane; and, (ii) 2-enone-3hydroxy -5,5-dimethylcylohex, while TM2 was 4H-1,3-dioxin-4-one-2,3,6-trimethyl. These metabolites did not exhibit any irritant or allergic reaction as revealed by HET- CAM test. TM2 significantly inhibited the growth of H. pylori and Shigella toxin producing Escherichia coli (STEC) as evident by in vitro and microscopic observations of bacterial cell death. TM2 also induced the cell death and cytotoxicity, as revealed by cell viability test and western blot analysis. According to microscopic, flow cytometer and western blot analysis, TM2 treated cells displayed higher ROS, cell death, and apoptosis-related protein expression than TM1 and control. This study concluded that TM2 derived from T. atroviride was a potential therapeutic agent for anti-prostate cancer and antibiotic agent against MDR- H. pylori and STEC and it is also recommended to carry out further in vivo animal model experiments with improved stability of the metabolites for future pharmaceutical trails.

Zinc-chitosan nanoparticles induced apoptosis in human acute T-lymphocyte leukemia through activation of tumor necrosis factor receptor CD95 and apoptosis-related genes

Chitosan (CS), a novel biomaterial is widely used as a drug nano-carrier for cancer treatments. Towards this aim, anticancer and antibacterial activities of CS-nanoparticles-linked zinc (Zn-CSNPs) were evaluated. The particle size of CSNPs was lowered (113.09 nm) compared to Zn-CSNPs (160.7 nm). Both nanoparticles (CSNPs and Zn-CSNPs) were spherical in shape, polydispersive and homogenous. Fourier transforms infrared spectrophotometer (FTIR) and energy dispersive X-ray spectroscopy (EDX) analysis confirmed the different molecular arrangement of NPs and the presence of Zn in Zn-CSNPs and CS in both NPs, respectively. Zn-CSNPs had higher inhibitory activity against tested pathogens with a minimal inhibitory concentration (MIC) of 9.25-13.5 μg·mL-1 and showed the complete inhibition of Staphylococcus aureus and Escherichia coli. Zn-CSNPs have triggered the apoptosis through activation of first apoptosis signal receptor/cluster of differentiation 95 (Fas/CD95), and apoptotic-regulatory genes and caused 65-70% of cellular damage in human acute T-lymphocyte leukemia (6T-CEM) cells. Overall, internalizing properties of Zn from CSNPs is a promising therapeutic approach to treat Zn-deficiency related diseases particularly human acute leukemia (HAL).