OBJECTIVETo prepare sodium alginate-nanohydroxyapatite composite material and to explore its feasibility as a bone repair material.

METHODSSodium alginate-nanohydroxyapatite composite material was prepared using chemical cross-linking and freeze-drying technology. The composite was characterized by X-ray diffraction (XRD) and scanning electron microscope (SEM) and its porosity was measured by liquid displacement method. The fifth passage of bone marrow stromal stem cells (BMSCs) were incubated on the composite material and then growth was observed by inverted microscope and SEM. BMSCs were cultured with liquid extracts of the material, methyl thiazolyl tetrazolium (MTT) assay was used to calculate the relative growth rate (RGR) on 1, 3, 5 d and to evaluate the cytotoxicity. Fresh dog blood was added into the liquid extracts to conduct hemolysis test, the spectrophotometer was used to determine the optical density (OD) and to calculate the hemolysis rate.

RESULTSSodium alginate-nanohydroxyapatite composite material displayed porosity, the porous pore rate was (88.6 +/- 4.5)%. BMSCs showed full stretching and vigorous growth under inverted microscope and SEM. BMSCs cultured with liquid extracts of the material had good activities. The toxicity of composite material was graded as 1. Hemolysis test results showed that the hemolysis rate of the composite material was 1.28%, thus meeting the requirement of medical biomaterials.

CONCLUSIONThe composite material fabricated in this study has high porosity and good biocompatibility.

Alginates ; Biocompatible Materials ; Cells, Cultured ; Glucuronic Acid ; Hexuronic Acids ; Humans ; Mesenchymal Stromal Cells ; Porosity ; Tissue Engineering ; Tissue Scaffolds

Objective: Abstract: Objective: To investigate the expression and significance of miR-138 and programmed cell death protein 1 (PD-1) in the patients with hepatitis B virus (HBV)-related hepatocellular carcinoma (HCC). Methods: A total of 30 patients with HBV-related HCC, 20 with HBV-related cirrhosis (LC) and 30 with chronic hepatitis B (CHB) were recruited from Jiaozuo People′s Hospital. The blood samples from all patients and the peritoneal effusion samples from HCC and LC patients were collected. The levels of miR-138 and soluble PD-1 (sPD-1) in blood and peritoneal effusion samples were detected by real-time PCR and ELISA, respectively. The expressions of PD-1 in T lymphocytes were measured with flow cytometry and western blot. The targeting effect of miR-138 on the 3′-non-coding region (3′-UTR) of PD-1 gene was verified by the dual-luciferase reporter gene system. Results: The relative expression levels of miR-138 in the peritoneal effusion and plasma of HBV-related HCC patients were significantly lower than those in LC and CHB patients (P＜0.05). The serum sPD-1 levels and the expression levels of PD-1 in CD3 + T lymphocytes of HBV-related HCC patients were significantly higher than those in LC and CHB patients (P＜0.05). The relative expression levels of miR-138 were negatively correlated with serum sPD-1 levels and the expression levels of PD-1 in CD3 + T lymphocytes (P＜0.05). The dual-luciferase reporter gene system and western blot results demonstrated that there was a targeting relationship between miR-138 and the 3′-UTR of PD-1 gene. After miR-138 was transfected, the expression level of PD-1 was significantly down-regulated. Conclusion miR-138 participates in the development and progression of HBV-related HCC probably by targeting PD-1.