Properties of a liposomes-mediated thermo-sensitive alginate/alpha-tricalcium phosphate/collagen Ⅰ composite hydrogel / 中国组织工程研究

BACKGROUND: The thermo-sensitive composite hydrogels have gained increasing interest in bone regeneration domain due to their biomimetic extracellular matrix (ECM) structure, good biocompatibility, minimal invasive performance and in situ molding. OBJECTIVE:To prepare a thermo-sensitive injectable alginate/α-tricalcium phosphate (α-TCP)/collagen I (Alg/TCP/Col) composite hydrogel and explore its characterization. METHODS:Ca-carrying interdigitation-fusion vesicles (Ca-IFVs) were prepared. The liposomes carrying the optimal concentration of calcium ions were selected for the following experiments by investigating their encapsulation efficiency and drug loading rate. Alg/TCP/Col precursor solution (Alg or Alg/TCP precursor solution) was mixed with Ca-IFVs at 37℃ in different proportions (5, 10, 15, 20) to prepare thermosensitive hydrogels. The structure, rheology behavior, volume swelling ratio, and mechanical properties of the composite hydrogel were observed. MC3T3-E1 cells were co-cultured with Alg/TCP/Col, Alg, and Alg/TCP hydrogels, respectively. Then, morphology of the cells was observed by confocal microscopy at 1, 3, 7 days after co-culture. RESULTS AND CONCLUSION:(1) The pore size of the freeze-dried hydrogel was 50-100 μm, and TCP particles uniformly adhered to the surface of the Alg/TCP hydrogel surface. The Alg/TCP/Col hydrogel was a dense aggregate with collagen fibers in contrast to the Alg/TCP hydrogel. (2) The Alg/TCP/Col hydrogel exhibited a suitable phase transition temperature (Tm) between 35-39℃. (3) The volume swelling ratio of the hydrogel was increased with the increase of Ca-IFVs size. When the α-TCP complex was added into the Alg/TCP hydrogel, the swelling ratio decreased slightly. Alg/TCP/Col hydrogel exhibited a higher swelling ratio than the Alg/TCP hydrogel. (4) When the mixture ratio of precursor solution to liposome was 10, the compressive modulus of Alg/TCP/Col hydrogel and Alg/TCP hydrogel was significantly higher than that of the Alg hydrogel (P<0.05). (5) When the mixture ratio of precursor solution to liposome was 10, round MC3T3-E1 cells were observed on the Alg hydrogel; the cells on the surface of the Alg/TCP hydrogel were scattered and tended to extend; the cells on the surface of the Alg/TCP/Col hydrogel had a stress-extended morphology, and grew into the hydrogel, and meanwhile, the cell number increased significantly. To conclude, the liposome-mediated Alg/TCP/Col has good mechanical properties and cytocompatibility.

Effect of shengmai injection on TRAIL death receptor of patients with congestive heart failure / 中国中西医结合杂志

<p><b>OBJECTIVE</b>To explore the levels of DR4 and DR5, the death receptor of soluble tumor necrosis factor-related apoptosis inducing ligand (TRAIL) in the patients with congestive heart failure (CHF) and the effect of shengmai injection (SI) on them.</p><p><b>METHODS</b>Sixty-four CHF patients were randomized into two groups, the SI group treated by SI and the control group treated with conventional treatment. Another 30 healthy persons were enrolled as the healthy control group. The serum levels of sDR4 and sDR5 were determined by sandwich ELISA before and after treatment.</p><p><b>RESULTS</b>The serum levels of sDR4 and sDR5 were obviously higher in CHF patients than in the healthy control subjects (P < 0.01), showing a rising trend with the aggravation of the degree of cardiac function impairment. Levels of sDR4 and sDR5 were lowered in the two treated groups after treatment, with better effects gotten in the SI group.</p><p><b>CONCLUSION</b>Close relationship presents between cardiac function status and levels of DR4 and DR5 in patients with CHF. DR4 and DR5 might play an important role in the occurrence and progression of myocardial cell apoptosis in patients with CHF, and SI may acts vitally to slow down the progress of CHF and improve patients' heart function by decreasing the levels of sDR4 and sDR5.</p>

Geographical differences in blood pressure of male youth aged 17-21 years in China.

Hypertension is one of the most prevalent cardiovascular risk factors in the adult Chinese population. The prevalence distribution of hypertension differs geographically in adults, since hypertension is influenced by environment factors, such as climate, altitude and economic. The aim of the present study was to study the prevalence of hypertension and measure the blood pressure (BP) level, and to compare and observe the geographical distribution of borderline or high BP in Chinese male youth. A cross-sectional survey on constitution and health of Chinese recruit youth was carried out in 2001, using the cluster sampling method. Two to four counties or cantons were selected as survey spots from all the 27 provinces or autonomous regions and four municipalities in China according to its population, geography and economy, except for Hong Kong, Tai Wan and Macao. The total survey spots were 100 counties or cantons. At each survey spot, all the recruit youth aged 17-21 years were surveyed, and data from a total of 81,193 recruits were collected. In the analysis, female youth and male subjects with diseases in heart, kidney, or other organs that could cause high BP were rejected. In all, the analysis sample was 72,895 subjects. Two standardized BP measurements were obtained. According to the P, P centile values of Chinese children and adolescent BP references, and adult's critical hypertension diagnosis standard recommended by the WHO, all the subjects were categorized into seven groups. The relationships between BP and physical indexes, age, heart rate, vital capacity and area were analyzed by using multiple step-wise regression. The prevalence rate of borderline and high BP of male youth in China was 13.3% and 5.0% respectively. There were significant differences in the prevalence rate of relatively high (borderline and high) BP and overall BP among youth from different areas. BP and the prevalence rate of relatively high BP were highest in youth from north China and the northeast areas among the six areas, with a prevalence rate of borderline 25.9% and 14.7%, and the high 10.5% and 5.7% respectively. However, the prevalence rate of relatively high BP of youth from the southwest area was the lowest among the six areas, with a prevalence rate of borderline 5.2% and high 2.3%. The results of multiple step-wise regression analysis showed that height, body mass index, age, heart-rate, vital capacity, economic status were positively correlated with BP, whereas annual mean air temperature, rainfall and altitude were negatively correlated. The results of this study showed that there were significant differences in the prevalence rate of relative high BP in male youth from different areas in China, and that BP was influenced by physical status and living area.