BACKGROUND: Fibrous scaffolds prepared by electrospinning possess similar structure to extracellular matrix, and exhibit convenience in introducing bioactive ceramics into polymer matrices, which have distinct superiority in making bone tissue scaffolds materials.OBJECTIVE: To evaluate the bioactivity of gas-jet/electrospun nanosized hydroxyapatite (nHAP)/poly (3-hydroxybutyrate) (PHB) scaffolds for being used as bone tissue engineering scaffolds.DESIGN, TIME AND SETTING: The in vitro cytology experiment was performed at the State Key Laboratoty of Oral Diseases,Sichuan University between March 2008 and April 2009.MATERIALS: The gas-jet/electrospun PHB and 10% nHAP/PHB scaffolds were prepared.METHODS: Rats bone marrow-derived mescenchymal stem cells were incubated on the nHAP/PHB scaffolds were served as experimental group, incubated on the PHB scaffolds were as control group, and cells incubated on cell culture plate were consided to be blank control group.MAIN OUTCOME MEASURES: mRNA transcript expression of bone-related markers, including alkaline phosphatase, type I collagen, and osteocalcin, were quantified utilizing reverse transcription-polymerase chain reaction (RT-PCR) at day 14 after culture.RESULTS: After 14 days, the bone-related markers were expressed in three groups, and had higher transcript levels in the cells cultured on the nHAP/PHB scaffolds than those on the PHB scaffolds and cell culture plate.CONCLUSION: The gas-jet/electrospun nHAP/PHB scaffolds present good bioactivity in vitro and have the potential to be used in bone tissue engineering.

BACKGROUND:Poly(3-hydroxybutyrate) is approved as its excel ent biocompatibility, biodegradability and piezoelectric properties, but there are also some deficiencies, such as high breakability and poor hydrophilicity. METHODS:Poly(3-hydroxybutyrate) was mixed with different mass percentages of nanohydroxyapatite (0, 10%, 20%and 30%) to prepare new composite fibrous scaffolds through electrospinning process. The microstructure, group composition, crystal ine phase distribution, thermal properties and surface wettability of the scaffolds were detected. RESULTS AND CONCLUSION:Under the scanning electron microscope, with the increase of nano-hydroxyapatite content, more and more nano-hydroxyapatite particles were distributed evenly on the composite fiber surface;the fiber surface was basical y covered with nano-hydroxyapatite particles at the content of 30%, and the roughness of the fiber surface also increased. Results from differential scanning calorimetry and X-ray diffraction showed that the nano-hydroxyapatite reduced the crystal inity of poly(3-hydroxybutyrate) and the crystal tacticity, and this phenomenon became more evident with the increase of nano-hydroxyapatite content. Additional y, the higher the content of nano-hydroxyapatite content, the lower the contact angle and the higher the hydrophily. These findings indicate that the nano-hydroxyapatite/poly(3-hydroxybutyrate) ultrafine-fibrous scaffold using electrospinning technology can effectively improve the surface wettability and crystal inity of the material as wel as the material hydrophily and brittleness, and the higher the content of nano-hydroxyapatite, the more obvious the effect.

Biliary stent has been widely used in the treatment of biliary stricture and obstruction, it can relieve the pain of patients effectively, but bacterial infection and stent obstruction are still troublesome after surgery. We introduce the mechanism of infection and stent blockage caused by bacterial invasion after biliary stent implantation, and expound the formation mechanism of bacterial biofilm and bile sludge in this review. Antibacterial biliary stent is an effective way to inhibit biliary tract infection, the literatures on antibacterial modification of biliary stent with different antibacterial methods in domestic and abroad are reviewed, and the research prospect of antibacterial biliary stent is summarized and prospected.
Anti-Bacterial Agents/pharmacology* ; Bile ; Biliary Tract ; Cholestasis ; Humans ; Stents

Ankle sprains are one of the most common surgical injuries in clinic. In this article, the foot anatomy structure was elaborated, and the biomechanics of ankle ligaments during sports was mainly reviewed. At the same time, the mechanism of ankle sprains was analyzed, the principal means of ankle sprains, prevention and rehabilitation at present were summarized, and the use of ankle braces to prevent ankle sprains as well as its research progress were introduced emphatically. The classification and characteristics of ankle braces were then summarized, and the prevention of ankle sprains and development of ankle braces were prospected. The multiple ankle lateral ligament damage was due to the physiological structure differences between lateral and medial ligaments of the ankle joints, and such structure characteristic should be considered while improving ankle braces and designing new ankle braces. Wearing ankle braces plays a key role in ankle sprains protection, which can shorten the recovery time and avoid re-injury in clinical rehabilitation. For rehabilitation of severe ankle sprains, semi-rigid ankle braces are better than elastic ones.

Objective To explore the mechanism of ankle sprain varus, a kind of human ankle brace with asymmetric physiological structure which can protect the ankle effectively is designed. Methods The anatomic factors of ankle varus were analyzed firstly, and a kind of ankle brace with asymmetric structure was designed based on asymmetric structure of ankle joint by anatomy. Using Kinect system and Geomagic Studio software, 3D scanning and digital modeling on ankle joint of a male adult were performed, and the ankle model was established by 3D printing technology. With EVA film, silica gel film and wrapped edge copper network as raw materials, two kinds of ankle brace with asymmetric structure were prepared by 3D draping and composite materials processing technology. The shaping properties, tensile properties, fatigue performance, outer fabric breathability and friction of the designed brace were tested. Results The outside of ankle brace with asymmetric structure had good shaping property, low tensile elastic recovery rate. Under the effect of repeated small load, EVA composite materials and silicone composite materials could keep good elastic recovery and effectively bear external varus forces. The results from air permeability and grinding test showed that polyester material was a kind of suitable fabrics for the outer lining material. Conclusions The mechanical properties of ankle brace with asymmetric structure can meet the requirement of ankle varus protection. The fabric of ankle brace can improve moisture permeability and frictional properties.

Objective To investigate the effect of propofol on pyroptosis and A549 cells via the NLRP3/ASC/caspase-1 pathway.Methods Establish a three-dimensional culture model of A549 tumor cells using ultra-low attachment plates,A549 cells were cultured using ultra-low adsorption culture plates to establish a three-dimensional culture model.The CCK-8 method was used to detect the effect of propofol on A549 cell proliferation;the inflammatory factors interleukin(IL)-18,IL-1β,and IL-6 were detected in the A549 lung cancer cell supernatants using enzyme-linked immunosorbent assays;western blotting was used to detect the expression levels of pyrolysis-asso-ciated proteins NLRP3,ASC,caspase-1,GSDMD-N,and IL-1β in A549 lung cancer cells in each group.Results Compared to the blank control group,the survival rate of A549 cells in low,medium,and high concentrations of propofol in each group decreased in turn(P＜0.05);the levels of inflammatory factors IL-18,IL-1β,and IL-6 in the A549 cell supernatant,and scorch related protein NLRP3,ASC,caspase-1,GSDMD-N,and IL-1β increased with the increased propofol concentrations(P＜0.05).Conclusion The three-dimensional culture model of lung cancer A549 cells was successfully established using the ultra-low adsorption culture method.Propofol can promote cell apoptosis and inhibit the pyroptosis of A549 lung cancer cells via activating the NLRP3/ASC/caspase-1 pathway.