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.

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.

[Abstract ] Objective Silicosis is one of the most serious occupational diseases in China .In this study,we explored the reg -ulatory effect of N-acetyl-seryl-aspartyl-lysyl-proline ( Ac-SDKP ) on angiotensin ( Ang ) Ⅱ-induced extracellular signal-regulated ki-nase ( ERK1/2) and Jun N-terminal kinase ( JNK) signals and its inhibitory effect on the differentiation of human embryonic lung MRC-5 fibroblasts to myofibroblasts via Ang Ⅱ-induced ERK1/2 and JNK signals . Methods Human embryonic lung MRC-5 fibro-blasts were induced by Ang Ⅱand pre-treated with the JNK signal inhibitor ( SP600125 ) , the ERK1/2 signal inhibitor ( PD98059 ) or Ac-SDKP.The proliferation of the cells was measured by MTT assay .The expressions of αS-MA, SRF, p-ERK1/2 and p-JNK were determined by immunocytochemical staining , and the expression levels of these proteins and collagen Ⅰwere detected by Western blot .Results The A value of Ang Ⅱ group (0.56 ±0.08) measured by MMT assay was 2.07 fold as control group ( 0.27 ±0.05 ). Pretreatment with SP600125 , PD98059 and Ac-SDKP, the A value were (0.39 ±0.02), (0.40 ±0.03) and (0.36 ±0 0.5) that had a statistical significance with Ang Ⅱgroup.The up-regulation of colla-gen type Ⅰ,α-SMA, SRF were induced by Ang Ⅱ by 4.50, 3.50 and 3.00 fold compared with control group.Moreover, the expression of p-ERK1/2 and p-JNK were increased as 6.71 and 7.90 fold as control. Pre-treatment with Ac-SDKP could inhibit p-JNK and p-ERK1/2 to 29.79% and 46.84% compared with AngⅡ group. Conclusion Ac -SDKP can inhibit the differentiation of human embryonic lung MRC-5 fibroblasts to myofibroblasts by regulating AngⅡ-induced JNK and ERK1/2 signals.

Objective To explore the efficacy of early hyperbaric oxygen therapy(HBOT)combined with median nerve electrical stimulation(MNES)in the treatment of severe traumatic brain injury(sTBI)and its impact on hemodynamics,coma degree,and neurological function of patients.Methods A total of 78 patients with sTBI admitted to the General Hospital of Western Theater Command from March 2020 to October 2021 were selected as the research subjects.The patients were randomly divided into the control group and the observation group,with 39 patients in each group.The patients in both groups underwent basic treatments such as water,electrolyte and acid-base balance,nutritional support,anti-infection,and decompressive craniectomy.On this basis,patients in the control group received early HBOT,while patients in the observation group received both HBOT and MNES.Their clinical efficacy was compared between the two groups.Before and after treatment,dual-channel transcranial Doppler ultrasound was performed to detect hemodynamic indicators such as peak systolic blood flow velocity(Vs),mean blood flow velocity(Vm),and pulsatility index(PI)in the middle cerebral artery of patients in the two groups.The Glasgow Coma Scale(GCS)score was used to evaluate the degree of coma of patients in the two groups,the National Institutes of Health Stroke Scale(NIHSS)score was used to assess the neurological deficits of patients in the two groups,and the enzyme-linked immunosorbent assay was used to measure the levels of central nervous system specific protein(S100-β),glial fibrillary acidic protein(GFAP),and myelin basic protein(MBP).Complications during treatment of patients in the two groups were recorded,and their incidence was compared.Results The total effective rate of patients in the control and observation groups was 79.49％(31/39)and 92.31％(36/39),respectively.The total effective rate in the observation group was significantly higher than that in the control group(x2=8.971,P＜0.05).There was no significant difference in Vm,Vs,and PI between the two groups before treatment(P＞0.05).After treatment,the Vm and Vs in both groups were significantly higher than those before treatment,while the PI was significantly lower than that before treatment(P＜0.05);and the Vm and Vs in the observation group were signifi-cantly higher than that those in the control group,while the PI was significantly lower than that in the control group(P＜0.05).There was no significant difference in GCS and NIHSS scores between the two groups before treatment(P＞0.05).After treatment,the GCS score in both groups was significantly higher than that before treatment,while the NIHSS score was significantly lower than that before treatment(P＜0.05);and the GCS score in the observation group was significantly higher than that in the control group,while the NIHSS score was significantly lower than that in the control group(P＜0.05).There was no significant difference in S100-β,GFAP,and MBP levels between the two groups before treatment(P＞0.05).After treatment,the S100-β,GFAP,and MBP levels in both groups were significantly lower than those before treatment(P＜0.05),and the S100-β,GFAP,and MBP levels in the observation group were significantly lower than those in the control group(P＜0.05).During treatment,the incidence of complications in the control and observation groups was 23.08％(9/39)and 20.51％(8/39),respectively,showing no significant difference(x2=2.328,P＞0.05).Conclusion Early HBOT combined with MNES shows good efficacy in treating sTBI,which can effectively improve the patients'hemodynamic level,alleviate the severity of coma,enhance neurological function,and promote early recovery of consciousness,without increased risk of complications.

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.
Animals ; Animals, Newborn ; Biocompatible Materials ; Cells, Cultured ; Lactic Acid ; chemical synthesis ; pharmacology ; Nerve Regeneration ; Olfactory Bulb ; cytology ; Polyglycolic Acid ; chemical synthesis ; pharmacology ; Polylactic Acid-Polyglycolic Acid Copolymer ; Rats ; Rats, Wistar ; Spinal Cord Injuries ; physiopathology ; Tissue Engineering ; methods ; Tissue Scaffolds ; chemistry

OBJECTIVETo perform a comparative proteomic analysis for identification of pulmonary proteins related to the progression of silicosis and anti-fibrotic effect of N-acetyl-seryl-aspartyl-lysyl-proline (Ac-SDKP).

METHODSBronchial instillation of SiO₂powder (for 4 or 8 weeks) was applied in rats to establish a silicosis model. Ac-SDKP treatment was performed before (prevention group) or after (treatment group) SiO₂instillation. The control group was treated by bronchial instillation of sodium chloride solution of the same volume as SiO₂powder for 4 or 8 weeks. Proteins in lung tissue were separated by two-dimensional gel electrophoresis and stained with colloidal Coomassie brilliant blue. The gel images were scanned with the Lab Scan III system and analyzed with Imagemaster 6.0. The protein spots with significant differences between two groups (i.e., P value was less than 0.05 in One-way ANOVA) and with a change in volume over 30% were defined as differential proteins. Comparison was performed between the silicosis group and control group after 4 or 8 weeks, between the Ac-SDKP treatment group and silicosis group after 8 weeks, and between the Ac-SDKP prevention group and silicosis group after 8 weeks. The differentially expressed proteins were subjected to in-gel digestion with trypsin and MALDI-TOF-MS and Mascot search engine analysis to identify these proteins.

RESULTSThirty-three differential proteins were identified. In comparison with the control group (4 weeks), the silicosis group (4 weeks) had 17 up-regulated proteins and 11 down-regulated proteins. In comparison with the control group (8 weeks), the silicosis group (8 weeks) had 16 up-regulated proteins and 12 down-regulated proteins. In comparison with the silicosis group (8 weeks), the Ac-SDKP treatment group had 5 up-regulated proteins and 6 down-regulated proteins, and the Ac-SDKP prevention group had 8 up-regulated proteins and 10 down-regulated proteins.

CONCLUSIONCritical regulatory proteins related to silicotic fibrosis and anti-silicotic effect of Ac-SDKP have been identified. These proteins may play an important role in proliferation, apoptosis, inflammation, epithelial-mesenchymal transition, and signal transduction in silicosis.

Animals ; Disease Models, Animal ; Lung ; metabolism ; Male ; Oligopeptides ; therapeutic use ; Proteome ; metabolism ; Rats ; Rats, Wistar ; Silicosis ; drug therapy ; metabolism