The effect of microencapsulated NGF-expressing NIH-3T3 cells on bioengineered dermis function in vitro / 生物医学工程学杂志

Nerve growth factor (NGF) can promote the regeneration of peripheral nerve as well as contraction and reepithelization of wound. We constructed a bioengineered dermis containing microencapsulated NGF-expressing NIH-3T3 cells and study the effect of the microencapsule to the bioengineered dermis and seed cells. NGF gene was transfected into NIH-3T3 cells and enclosed into alginate-poly-L-lysine-alginate (APA) microencapsulation and cultivated in vitro. Content of NGF in microencapsules culturing supernatant was measured by enzyme linked immunosorbent assay (ELISA) method. These microencapsules were co-cultured with epidermic cells and fibroblast cells. Bioengineered dermis was constructed with NGF-expressing micorencapsules as seed cells using tissue engineering method. NIH-3T3 microencapsules, empty microencapsules, normal culture media were control groups. After one week culture, the characteristics of the dermis were described by MTT test, the content of hydroxyproline (HP), HE staining and ultrastructure photograph. We found the NGF-expressing microencapsulates can secret NGF steadly after cultured 8w in vitro, promot the proliferation of epidermic cells and secret collagen of fibroblast cells. These functions can maintaine in bioengineered dermis. So NGF-expressing NIH-3T3 microencapsulates can promote the quality of bioengineered dermis.

Clinical effects and operative techniques of external ultrasound liposuction in lower extremities / 中华医学美学美容杂志

Objective To discuss the therapeutic effects and safety of external ultrasound liposuction to adipose tissue of lower extremities and to summarize the operative techniques. Methods According to the requests of 81 patients, external ultrasound liposuction were performed for them on thighs (n=60), and legs (n=21). It was that the volumes of anesthetic drugs and pure fat as well as the variations of body contour between preoperation and one to three months after operation in every area were recorded. Results Fat aspiration volume in thighs was 3673ml per person with the highest 6100ml. The scale of the circumference of thighs decrease (4.65?1.10)cm with the highest 12.5 cm. In legs, fat volume was 650ml per person with the highest 1200ml, scale decrease (3?1.02) cm with the highest 9cm. Patients had less blood loss, less pain and discomfort with even skin appearance and without severe complications. In the course of operation, knowing well the anatomical character of lower extremities, injecting the anesthetic drugs completely, using appropriate ultrasound time, and sucking in uniform layer were all crucial factors to guarantee the success of the operation. Conclusion External ultrasound liposuction is a safe, effective body contour remodeling operation in lower extremities. Skillful operator is a very important element to successful operation.

Acceleraton of nerve regeneration following acellular allogeneic nerve grafting by bFGF / 中华显微外科杂志

Objective To evaluate the promoting effect by bFGF on nerve regeneration following acellular allogeneic nerve grafting,and the effects of various concentration of bFGF on axon growth. Methods The animals were divided into 1 000U/ml, 500U/ml, 250U/ml,100U/ml and normal saline groups. Immunohistochemistry staining of neurofilament-160 and S-100 was used to show the length of axonal growth and Schwann cell infiltration 10 days after the surgery. Results The average distance of regenerated nerve fibers in the high dose groups (1 000U/ml and 500U/ml) was longer than that in the normal saline control group;but there was no difference between the low dose groups (250U/ml and 100U/ml) and the control group. Conclusion Early use of bFGF when acellular allogeneic nerve grafted to bridge peripheral nerve defect may obviously promote axon growth speed.

The study of biocompatibility of polyurethane sponges made in China / 医疗卫生装备

Objective To evaluate the biocompatibility of four kinds of polyurethane sponges made in China. Methods According to ASTM Standards for Medical Devices of America, polyurethane sponges are used to perform such biological tests as cytotoxicity test, acute toxicity test, pyrogenic reactions test, stimulation test of conjunctiva and cornea, sensitization test. The data are analyzed and evaluated according to the criterion. Results Reaction scales of these polyurethane sponges in cytotoxicity are 0 or 1 level. No toxicity effects and pyrogenic reactions are observed in vivo test. No conjunctiva and cornea irritation reactions and no sensitization reactions are found. Conclusions The four kinds of polyurethane sponges have high biocompatibility and can become ideal dressings of Vacuum-Assisted Closure.

Biocmpatibility research of a hemostatic agent-ZSM-5 zeolite / 医疗卫生装备

Objective To evaluate the biocompatibility of ZSM-5 zeolite and provide an experimental basis for developing the first-aid hemostatic agent.Methods According to Chinese evaluation standards on medical devices and biological tests,the cytotoxicity in vitro,hemolysis test,acute toxicity of system,pyrogen test,intracutaneous stimulation,sensitization and micronucleus test were studied in ZSM-5 zeolite.In order to find out the side-effect of the zeolite granules' remains left in the wounds to body,muscle implantation test was studied.Results There were no obvious cytotoxity,hemolysis reaction.Acute tocicity,pyrogen reaction,intraeutaneous stimulation,sensitization and potential mutagenesis in themicronucleus test were observed.Their results were a11 consistent with the Chinese biological evaluation of medical devices.Obvious inflammatory reaction was observed when ZSM-5 zeolite was implanted in muscle for 12 weeks.Conclusion The ZSM-5 zeo1ite has reliable biocompatibility.But zeolite can cause inflammatory reaction when it is remained in the wound surface for long term.