Synthesis of poly(glycerol sebacate) and its research hotspots / 中国组织工程研究

BACKGROUND: Poly(glycerol sebacate) holds excellent and good biocompatibility, flexibility and degradability, which is widely used in soft tissue replacement and tissue engineering, drug delivery carrier, wound dressing, and bone-cartilage regeneration. OBJECTIVE: To summarize the research progress in the optimal synthesis and medical application of poly(glycerol sebacate) and its composites. METHODS: PubMed, Elsevier, CNKI and WanFang databases were retrieved. The key words were “poly(glycerol sebacate), synthesis, cardiac muscle, blood vessels, nerves, skin, drug delivery carrier, wound dressing, bone regeneration” in English and Chinese, respectively. Finally, 43 articles eligible for the inclusion criteria were obtained. RESULTS AND CONCLUSION: In recent years, poly(glycerol sebacate) has attracted much attention because of its many excellent properties. Many basic scientific studies and animal experiments have confirmed that it is suitable for tissue engineering. Conventional poly(glycerol sebacate) curing process requires high temperature, high vacuum and long duration, which prevents the polymer from binding directly to cells or temperature-sensitive molecules, resulting in some limitations in its application. The composite scaffold material synthesized with a variety of other materials can make up for the corresponding shortcomings of its application in myocardial and vascular tissue engineering, drug delivery carrier, nerve guiding materials, skin and wound dressing, and bone-cartilage tissue engineering. At present, most of the studies on poly(glycerol sebacate) composites focus on the cytobiology level, and few studies focus on the mechanism of action in vivo. Further study may develop an important material for tissue replacement.

Comparison of therapeutic effect between percutaneous kyphoplasty and pedicle screw system on vertebral compression fracture / 中华创伤杂志(英文版)

<p><b>OBJECTIVE</b>To compare the clinical efficacy of percutaneous kyphoplasty (PKP) with pedicle screw system (PS) in the treatment of vertebral compression fracture(VCF).</p><p><b>METHODS</b>Eighty-six patients with VCF were treated either by PKP (Group A, n equal to 30) or PS (Group B, n equal to 56). The anterior, intermediate, and posterior heights of the vertebrae body, visual analogue pain scale (VAS) before and after operation, the duration of operation, and amount of blood loss between two groups were compared.</p><p><b>RESULTS</b>No statistical difference was noted regarding the vertebral height between two groups. Significant difference was seen in VAS, duration of operation and amount of blood loss between the two groups (P less than 0.01).</p><p><b>CONCLUSIONS</b>Percutaneous kyphoplasty has the similar therapeutic efficacy with pedicle screw system in treatment of VCF with a minimal invasion, less operation time and blood loss. For those with posterior wall destruction, PS is deemed favorable.</p>

Biomechanical analysis of fracture fixation with external fixator in vivo / 中华创伤杂志(英文版)

<p><b>OBJECTIVE</b>To investigate the different ways of measuring the main axial strain during treatment with an external fixator and to find the suitable compression loaded by the external fixator at an early stage.</p><p><b>METHODS</b>Eighteen healthy big-ear rabbits were randomly divided into two groups according to different measuring methods: Group A and Group B. In Group A, a strain gauge was affixed to the external tibial cortex with 502 glue, and in Group B, a bone cement-coated strain gauge was installed on the internal tibial cortex. Groups A and B were divided into two subgroups A1, A2 and B1, B2, respectively, according to the pressure of half of and the same as the body weight. A Z-shaped left mid-shaft tibial osteotomy was performed and fixed by an external fixator.</p><p><b>RESULTS</b>The scaler curves of Group A changed dramatically during the early stage. The trendlines of the internal and external cortex went consistently after reaching the stable stage while the latter strain value was higher than the former. The time for Group B reaching the stable stage was short, but its absolute strain value was less than that of Group A. Before they were pressed to the stable stage, the declined speed of Subgroup A1 was more slowly than that of Subgroup A2 while the results of Subgroups B1 and B2 were same. Group A had an ascending trend after it declined while Group B didn't have. After they reached the stable stage, both Subgroups A1 and A2 had a declining trend while Subgroup A2 was more quickly than Subgroup A1, Subgroup B1 was kept at a definite level while Subgroup B2 fluctuated.</p><p><b>CONCLUSIONS</b>The axial strain under external fixator can be measured by bone cement coated-strain gauge in vivo. The data may suggest that half of the body weight load was suitable for external fixator.</p>