PRGD composite nerve conduit in repair of human peripheral nerve defect in upper extremity / 中华显微外科杂志

Objective To explore the clinical efficacy of PRGD composite nerve conduit in the treatment of human large-diameter,critical peripheral nerve defect in upper extremity.Methods From December,2011 to August,2014,19 patients with large-diameter,critical peripheral nerve defect in upper extremity were treated with PRGD composite nerve conduit.The patients were followeded-up periodically.The sensory and motor function recovery,high frequency ultrasound,and EMG were employed to assess the efficacy.Results The patients were followed up for an average time of 12-32 months(mean 21.75 ± 6.86 months),sensory and motor function recovered excellent in 7 patients,satisfactory in 7 patients,tolerable in 3 patients and no improvement in 2 patients were obtained according to the peripheral nerve function assessment standard built by British medical research council,the rate excellent and satisfactory results was 73.7％.Conclusion It is clinically promising to use PRGD composite nerve conduit to repair large-diameter,critical peripheral nerve defect in upper extremity,thus laying a foundation for its further application in clinical practice.

Interaction of olfactory ensheathing cells with nerve repairing scaffolds / 中南大学学报(医学版)

OBJECTIVE@#To investigate a new way to yield plenty of high purity olfactory ensheathing cells (OECs) and its biocompatibility with appropriate scaffolds.@*METHODS@#OECs were prepared from neonatal Wister rats and co-cultured with poly [LA-co-(Glc-alt-Lys)] (PLGL). Its contact angle, adherent rate, and activity rate were tested.@*RESULTS@#The contact angle of poly (D, L-lactic acid) (PDLLA) (84.5 degree+/-1.5 degree) was significantly higher than that of PLGL (52.6 degree+/-0.8 degree), the adherent rate of PLGL (80%) was significantly higher than that of the PDLLA (57%), and the activity rate of PLGL (88%) was much higher than that of the PDLLA (76%).@*CONCLUSION@#PLGL possesses better hydrophilicity and biocompatibility than PDLLA, and it can provide a better cell growth circumstance which is helpful for the effective treatment of nerve injury.

Bioactivity and biocompatibility of hydroxyapatite/DL-poly lactic acid composite: In vivo implantation / 中国组织工程研究

BACKGROUND:Hydrolysis in vivo is the key mechanism of degradation in DL-polylactic acid (PDLLA). When it is combined with hydroxyapatite (HA), could the biodegradation and weight loss rate be improved? OBJECTIVE: To observe the changes in the interface and structure of HA/PDLLA composite after in vivo implantation into rabbit femoral defects.DESIGN: Randomized grouping and controlled observation.SETTING: Biomedical Materials and Engineering Research Center, Wuhan University of Technology.MATERIALS: Forty healthy adult Japan White Rabbits of 2.0-2.5 kg, either male or female were provided by the Animal Experimental Center of Hubei Province (No. SCXK. 2003-0005).METHODS: The experiment was conducted in Biomedical Materials and Engineering Research Center, Wuhan University of Technology from June 2005 to March 2006. ①The rabbits were randomly divided into two groups: HA/PDLLA group and PDLLA control group with 20 animals in each group. After anesthetized with ketamine and proazamine, the sample rods of HA/PDLLA and PDLLA were respectively implanted into the drilled bone cavities (φ5 mm × 8 mm) among condyles of femur sites of the rabbits, and the rod could be slightly higher than the surface of bone substance. The samples were covered by periosteum and skin, and then the skin and periosteum were repositioned. ②The complete implants and peripheral bone tissues were taken out respectively after 3, 6, 12 and 24 weeks implantation. The changes in the interface and structure of HA/PDLLA composite after in vivo implantation were observed by using scanning electron microscope (SEM, JSM-5610LV, Japan).MAIN OUTCOME MEASURES: Changes in the interface and structure of HA/PDLLA composite after in vivo implantation.RESULTS: Totally 40 rabbits were involved in the result analysis. After the materials were implanted, HA granules shed from the material surface, some fibroblasts grew into the tissue and a little new osteotylus was formed, indicating HA/PDLLA composite had capabilities of bone-formation and bone-connection. After 24 weeks implantation, the material was divided and wrapped by tissues, neogenetic bone tissue grew into the material, and the fracture healed well,indicating HA/PDLLA composite had good biocompatibility. As for biodegradable PDLLA polymer, hydrolysis in vivo is the most main mechanism of degradation; the degradation speed was decreased owing to being compounded with HA.CONCLUSION: HA/PDLLA composite has capabilities of bone-formation and bone-connection; the biocompatibility of the composite is improved accordingly on account of the decrease of the degradation speed. HA/PDLLA composite is suitable for clinical application as absorbable materials for internal fixation.

A study on the mechanical properties of poly-D,L-lactic acid/hydroxyapatite compound fibers / 生物医学工程学杂志

The PDLLA/HA compound fibers with excellent properties could be obtained by melt-spinning. This study inquired about the mechanical properties, change rule and influencing factors. The results showed that the composites fibers of mechanical properties were good in the PDLLA(molecular weight 120,000) to which were added the 4-20 microm HA particles. In the matrix of PDLLA with accretion (10%) of HA particles, the tensile strength of the compound fibers was the highest, compared with the others. The tensile strength of the compound fibers of PDLLA (molecular weight 20,000-300,000) was high. The tensile strength of the compound fibers decreased with the increase of the fiber diameter, and the PDLLA/HA fibers 40-60 micrometers in diameter had the highest elongation at break.

Study on the sealing capability of a calcium phosphate root canal filling material / 生物医学工程学杂志

To evaluate the sealing potential of self-designed root canal filling material made of calcium phosphate cement (alpha-TCP/TTCP, CPC), the apices of root canals of six adult dogs were purposely perforated and enlarged up to the No 40 instrument. Then CPC was used to fill the root canal. Mean while either calcium hydroxide (Ca(OH)2) paste or hydroxyapatite (HA) paste was used as control. The animals were killed at 4, 12, 20 weeks postoperatively. The different materials about ways of apical closure, restoration periapocal tissues and adaptability to the dentinal surface were observed by histomorphology and scanning electron microscopic. This study revealed that CPC had excellent biocompatibility and adaptability to the dentinal wall. Its osteoconduction can promote the formation of calcific barriers and healing of periapical tissue. The apex can be closed completely. Compared with the control pastes it has advantages of ease of manipulation and better sealing capability. The results showed that CPC could be used as a root canal filling material for pupless teeth with open apex and destructive periapical tissue.

The Effect of Hydroxyapatite Ultrofine Powder on the Immunity Function of Tumor-bearing Mice / 华中科技大学学报（医学）（英德文版）

The inhibitory effect of hydroxyapatite ultrofine powder (HAUFP) on tumor and the effect on the immunity function of body were investigated. The levels of IL-2 in the spleen cells and serum TNF levels in the tumor-bearing mice at the 7th day and 14th after peritoneal injection of HAUFP were detected by using the methods of colorimetric analysis of MTT and crystal purple decoration, respectively. The disappearance of the ascites of the mice was observed. The results showed that the levels of IL-2 and TNF in the tumor-bearing mice were higher obviously in the drug-treated group than in the control group (P<0.01), the ascites growth was inhibited. It was suggested that HAUFP could increase the levels of IL-2 and TNF of the tumor-bearing mice and improve the immune function of body.

The Effect of Hydroxyapatite Ultrofine Powder on the Immunity Function of Tumor-bearing Mice / 华中科技大学学报（医学）（英德文版）

The inhibitory effect of hydroxyapatite ultrofine powder (HAUFP) on tumor and the effect on the immunity function of body were investigated. The levels of IL-2 in the spleen cells and serum TNF levels in the tumor-bearing mice at the 7th day and 14th after peritoneal injection of HAUFP were detected by using the methods of colorimetric analysis of MTT and crystal purple decoration, respectively. The disappearance of the ascites of the mice was observed. The results showed that the levels of IL-2 and TNF in the tumor-bearing mice were higher obviously in the drug-treated group than in the control group (P<0.01), the ascites growth was inhibited. It was suggested that HAUFP could increase the levels of IL-2 and TNF of the tumor-bearing mice and improve the immune function of body.