Programmable mechanical stimulation influences tendon homeostasis in a bioreactor system

Identification of functional programmable mechanical stimulation (PMS) on tendon not only provides the insight of the tendon homeostasis under physical/pathological condition, but also guides a better engineering strategy for tendon regeneration. The aims of the study are to design a bioreactor system with PMS to mimic the in vivo loading conditions, and to define the impact of different cyclic tensile strain on tendon. Rabbit Achilles tendons were loaded in the bioreactor with/without cyclic tensile loading (0.25 Hz for 8 h/day, 0–9% for 6 days). Tendons without loading lost its structure integrity as evidenced by disorientated collagen fiber, increased type III collagen expression, and increased cell apoptosis. Tendons with 3% of cyclic tensile loading had moderate matrix deterioration and elevated expression levels of MMP‐1, 3, and 12, whilst exceeded loading regime of 9% caused massive rupture of collagen bundle. However, 6% of cyclic tensile strain was able to maintain the structural integrity and cellular function. Our data indicated that an optimal PMS is required to maintain the tendon homeostasis and there is only a narrow range of tensile strain that can induce the anabolic action. The clinical impact of this study is that optimized eccentric training program is needed to achieve maximum beneficial effects on chronic tendinopathy management. Biotechnol. Bioeng. 2013; 110: 1495–1507. © 2012 Wiley Periodicals, Inc.     

The diagnostic value of combined detection of genetic markers and serum protein markers on breast cancer

Objective: The research is to explore the diagnostic value of several detection methods including separated and combined detection of the related genes and related proteins of breast cancer and combined detection of all genetic markers and serum protein markers on breast cancer. Method: The mRNA level expression of the related genes of breast cancer was detected by FQ-PCR technique and the ratio of BRCA-1, Myc, C-erbB2 and β2 micro-globulin was used to express levels of BRCA-1, Myc and C-erbB2; the related proteins of breast cancer were detected through ELISA. Then the research data was analyzed by SPSS19.0 software with t-test as comparison method, and ROC curve was used to calculate the sensitivity, specificity and accuracy of the diagnostic models. Result: No difference can be found among the six indexes in the control group and benign breast tumor group while compared with the benign breast tumor group and the control group, the breast cancer group was significantly different from them; combined detection of genes and that of proteins were both superior to their separated detection; all-marker combined detection was superior to separated detection, which is consistent with combined detection of genes and proteins. Conclusion: More detection indexes will not necessarily outcome better detection effect. Hence, appropriate detection indexes and number are needed to achieve better diagnosis effect. In order to conduct more specific method, more test samples are needed for further researches.     

Nanosecond pulsed electric fields prime mesenchymal stem cells to peptide ghrelin and enhance chondrogenesis and osteochondral defect repair in vivo

Science China Life Sciences - Mesenchymal stem cells (MSCs) are important cell sources in cartilage tissue development and homeostasis, and multiple strategies have been developed to improve MSCs...     

利用吸附性物质贮存昆虫病原线虫

昆虫病原线虫制剂产业化需要有效的贮存方法.本试验利用国产硅藻土和高分子凝胶,比较硅藻土和凝胶不同比例、不同温度及添加防霉剂,对线虫存活率、霉菌控制和线虫毒力的影响.线虫在10℃下24周后存活率仍达90.5%,线虫对大蜡螟幼虫的感染率仅下降19.5%.23℃下贮存8周时,存活率高于93%,但16周后几乎全部死亡;对测定昆虫的感染率8周后下降了26.8%.加入的食品抗霉剂对线虫存活率和感染率无明显影响,但防霉效果仅维持2周.结果表明,利用国产硅藻土可贮存Steinernema carpocapsae线虫.     

In vitro evaluation of natural marine sponge collagen as a scaffold for bone tissue engineering

The selection of a suitable scaffold matrix is critical for cell-based bone tissue engineering. This study aimed to identify and characterize natural marine sponges as potential bioscaffolds for osteogenesis. Callyspongiidae marine sponge samples were collected from the Fremantle coast of Western Australia. The sponge structure was assessed using scanning electron microscopy (SEM) and Hematoxylin and eosin. Mouse primary osteoblasts were seeded onto the sponge scaffold and immunostained with F-actin to assess cell attachment and aggregation. Alkaline phosphatase expression, von Kossa staining and real-time PCR were performed to examine the osteogenic potential of sponge samples. SEM revealed that the sponge skeleton possessed a collagenous fibrous network consisting of interconnecting channels and a porous structure that support cellular adhesion, aggregation and growth. The average pore size of the sponge skeleton was measured 100 to 300 μm in diameter. F-actin staining demonstrated that osteoblasts were able to anchor onto the surface of collagen fibres. Alkaline phosphatase expression, a marker of early osteoblast differentiation, was evident at 7 days although expression decreased steadily with long term culture. Using von Kossa staining, mineralisation nodules were evident after 21 days. Gene expression of osteoblast markers, osteocalcin and osteopontin, was also observed at 7, 14 and 21 days of culture. Together, these results suggest that the natural marine sponge is promising as a new scaffold for use in bone tissue engineering.