[Application of double skin island free forearm flap in the repair of large perforating defect of palate]

Objective:To explore the value of free forearm flap with double skin island in repairing large perforating defect of palate. Method:The free forearm flap with double skin island was used to repair 6 cases of large perforating palatal defect due to oral malignant tumor. Preoperative Allen test and ultrasound doppler examination were used to judge the forearm vessels. Result:All the free forearm flap with double skin island survived in 6 cases, followed up for 3 months to 24 months, the patients ate normally, swallowing without nasal regurgitation. The patients had mild to moderate nasal sounds, and the patients were satisfied with the effect of operation and the quality of life. Conclusion:The double skin island free forearm flap is a reliable method for repairing large perforating defect of palate, with satisfactory morphological function and good effect.

[Application of digital 3D imaging technique in flap design before maxillofacial soft tissue reconstruction]

Objective:Using digital technique to design the preoperative flap of oral and maxillofacial soft tissue defect, to instruct the operation and to provide the basis for making the individual femoral flap. Method:We chosed 7 patients with oral and maxillofacial malignancies to undergo thin-line CT scans of lower extremities and analyzed the data of CTA examination to measure the diameter, shape and length of vascular pedicle. Then selected the appropriate perforation as the source of blood supply for flap. The location of perforation was marked on the skin to simulate flap removal range.During the surgery according to the preoperative mark, draw lines and mark flap size. After flap preparation is completed, suture the donor area directly and build in negative pressure drainage tube. Result:All reconstruction of the anterolateral femoral artery descending perforator flap can show the skin, muscle, blood vessels and their adjacent relationship, and according to the size of the defect area, using Mimics 17.0 software simulation to cut flap which should be the same as the defect area. The main perforating branches and trunks of seven skin flaps were consistent with pre-operative examination and all skin flaps survived; the wound surface and the donor were all in stage Ⅰ healing. After operation, patients were followed up for 1-6 months and the form, quality and function of skin flaps all recovered well. Conclusion:The location of lateral femoral circumflex artery descending limb and perforating branch were accurately located by digital technique three-dimensional reconstruction technology, showing the spatial relationship among skin, muscle, blood vessels and bones. By combining with Mimics 17.0 software, it can achieve three-dimensional and accurate design of anterolateral thigh flap, reduce the donor injury and improve the successful rate of skin flap.

Extracorporeal magnetic approach to reduce the unwanted side-effects and improve antibacterial activity of Ag/Fe3 O4 nanocomposites in rat

While Ag nanoparticles hold great promise for broad spectrum antibacterial activity, the potential risks of Ag nanoparticles (NPs) on human health remain a challenge. In this study, Ag/Fe₃ O₄ composites have been successfully prepared and characterized by transmission electron microscopy, X-ray powder diffraction, and Fourier-transform infrared spectroscopy, and their magnetic and antibacterial properties have been assessed. In vivo results show that the antibacterial effect of 500 μg/mL Ag/Fe₃ O₄ nanocomposites was significantly higher than that of 1000 μg/mL AgNPs after 72 h of treatment (p < 0.01). Hematoxylin and eosin (HE) staining showed that squamous epithelium and dermis collagen fibers formed in the Ag/Fe₃ O₄ group after 8 days treatment. Wound closure was significantly better for the Ag/Fe₃ O₄ group than for the AgNPs group. On the other hand, there was less Ag in blood, liver, and kidney in the Ag/Fe₃ O₄ group, as more Ag was retained in the wound. According to lactate dehydrogenase, γ-glutamyl transpeptidase, and reactive oxygen species results, Ag/Fe₃ O₄ nanocomposites caused less unwanted side-effects. This work presents a new paradigm to reduce the unwanted side-effects of AgNPs and improve their antibacterial activity, providing a new avenue for wound healing. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 2029-2036, 2018.

Effect of "phase change" complex on postoperative adhesion prevention

BACKGROUND

Postsurgical peritoneal adhesion is a major clinical problem. Numerous anti-adhesion products have been studied, but none could be easily used to provide a physical barrier. In this study, we developed a "phase change" anti-adhesion barrier for reducing peritoneal adhesion by cross-linked copolymerization of O-carboxymethyl chitosan (CMC) and CaCl2 and addition of cyclosporin A (CsA).

MATERIALS AND METHODS

The CMC-CaCl2-CsA compound was characterized by equilibrium swelling rate, weight loss, releasing effect, and coagulation test, and its biosafety was characterized by acute oral toxicity, hemolysis, and cytotoxicity. Intestinal adhesion model was applied on 64 Sprague-Dawley rats, which received CMC, CMC-CaCl2, or CMC-CaCl2-CsA treatment. At postoperative days 7 and 14, the rats were euthanized, and adhesions were graded by an investigator blinded to the treatment groups, using a predetermined adhesion scoring system. The cecum and adhesion tissue were stained with hematoxylin and eosin and antibodies for matrix metalloproteinase-9 and TIMP-1 for further histopathologic examination.

RESULTS

The phase change anti-adhesive material exhibited effective blood clotting and were nontoxic in clotting experiments and acute toxicity test. The degradation rate could be adjusted using phosphate-buffered solution with varying pH. Adhesions were significantly reduced in the CMC-CaCl2-CsA treatment group compared with the control group (P < 0.001). Expression of matrix metalloproteinase-9 was stronger in CMC-CaCl2-CsA treatment group at 7 days after surgery.

CONCLUSIONS

"Phase-change" adhesive can undergo changes after application, and it inhibits the formation of abdominal adhesions after surgery. The material is convenient for using by surgeons and provides an effective tool for intestinal adhesion prevention.

Influence of reducing agents on biosafety and biocompatibility of gold nanoparticles

Extensive biomedical applications of nanoparticles are mainly determined by their safety and compatibility in biological systems. The aim of this study was to compare the biosafety and biocompatibility of gold nanoparticles (GNPs) prepared with HEPES buffer, which is popular for cell culture, and sodium citrate, a frequent reducing agent. From experimental results on the body weight and organ coefficients of acute oral toxicity tests, it could be observed that HEPES-prepared GNPs are biologically safer than citric-prepared GNPs at the same dose of 500 μg/kg. The in vitro cell viability was higher for HEPES-prepared GNPs than citric-prepared GNPs at 5.0- and 10.0-ug/mL concentrations. More reactive oxygen species (ROS) were generated in the cell suspension when supplemented with citric-prepared GNPs than HEPES-prepared GNPs when their concentrations were higher than 20 μg/mL. The results stated that HEPES-prepared GNPs had better biosafety and biocompatibility than citric-prepared GNPs. This study not only revealed the influence of reducing agent on biosafety and biocompatibility of nanomaterials but also provided accumulative evidence for nanomaterials in biomedical applications.

Graphical Abstract

[The pharmacokinetics of SC1001-sodium and SC1001-aminum in human body]

The pharmacokinetics of SC1001-Sodium and SC1001-Aminum in the human body was studied. After 200 mg SC1001-Sodium or SC1001-Aminum by oral administration, plasma concentration-time data were fitted to curves by means of the nonlinear least-square method, employing the program we ourselves compiled. With F-test, comparing gamma 2(1) -value and AIC-value, the linear one compartment open model was available. The mean pharmacokinetic parameters fitted one by one were as follows with the first value given belonging to SC1001-Sodium and the second to SC1001-Aminum: Ka: 0.7248 and 0.5102 h-1; Ke: 0.0597 and 0.1149 h-1; T1/2, a: 1.1437 and 1.8999 h; T1/2, e: 15.7428 and 6.1497 h; AUC: 600.15 and 28.61 micrograms.h/ml; Tm: 4.4798 and 4.3728h.