Objective To investigate the anti-infection and bone repair effects of composite scaffolds encapsulated with vancomycin and bone morphogenetic protein-2 (BMP-2).Methods Chitosan (CS) solution and nano-hydroxyapatite (n-HAP) mixed in a ratio of 1∶1 were made into solid materials by freeze drrying technology,and immerged into BMP-2/polylactic acid (PLA) and vancomycin/PLA microsphere solution to fabricate drug-loaded scaffolds.Efficiency of drug release was measured.After the induction of chronic infectious tibial bone defect,60 New Zealand white rabbits were assigned to isolate debridement group (Group Ⅰ),n-HAP/CS scaffold group (Group Ⅱ),n-HAP/CS + vancomycin/PLA group (Group Ⅲ) and n-HAP/CS + vancomycin/PLA + BMP-2/PLA group (Group Ⅳ) according to the random number table,with 15 rabbits per group.After 8 weeks of treatment,X-ray filming,Norden score,HE staining and narrow culture were performed to evaluate the anti-infection ability and bone repair ability in each group.Results Pore size of the n-HAP/CS scaffold constructed in this study ranged from 80 to 270 μm (mean,146.53 μm).Biomechanical test showed the elastic modulus of the scaffold material was (27.50 ± 1.58)MPa and the compressive strength was (0.75 ± 0.04)MPa.BMP-2/PLA and vancomycin/PLA microspheres into ball shape uniformly distributed on the scaffold pores.Drug-loaded scaffold showed relatively stable release of vancomycin and BMP-2 in a period of 18 days.With the extended time amount of the drug release gradually reduced.On the X-ray films 8 weeks after the treatment,sinus formation was visible in groups Ⅲ and Ⅳ,and emergence of periosteal reaction with focal low density shadow was demonstrated in groups Ⅰ and Ⅱ.Norden scores of groups Ⅰ,Ⅱ,Ⅲ and Ⅳ were (2.64 ±0.33) points,(2.63 ±0.36) points,(1.14 ±0.29) points and (0.89 ±0.42) points respectively,indicating group Ⅳ ranked the lowest compared with other three groups (P＜0.05) and group Ⅲ showed significant difference in comparison with groups Ⅰ and Ⅱ (P ＜0.05).HE staining showed massive infiltration of inflammatory cells and destroyed bone trabeculas in groups Ⅰ and Ⅱ,trabecular bone arranged neatly in groups Ⅲ and Ⅳ,and thicker trabecular bone in group Ⅳ than in group Ⅲ.Marrow culture showed obvious pale yellow colony formation in groups Ⅰ and Ⅱ,but no colony formation in groups Ⅲ and Ⅳ.Conclusions Vancomycin/BMP-2-loaded tissue engineering scaffolds are constructed successfully.Drug-loaded n-HAP/CS composite scaffold is identified as an ideal implant material for treatment of chronic osteomyelitis in rabbits

Objective: To study the effects of long chain PUFA, AA and/or DHA on the fatty acid composition, growth and development of the newborn rats hippocampal neurons in culture. Methods: The primary culture of the hippocampal neurons was carried out in vitro by using serum free medium and supplementing 4 ? mol/L AA, DHA, or AA and DHA, of which the total concentration were 4 ?mol/L, the ratios of AA∶DHA from 1∶2 to 16∶1, in medium. The hippocampal neuronal fatty acid composition was analyzed by gas chromatogram, and the neuronal size and length of hippocampal neurite were measured by image analysis. Results: There were significant positive correlations between the ratios AA∶DHA in medium and the AA percentage and the ratios AA∶DHA in hippocampal neurons. The soma area? body maximum? minimum diameter and process length of hippocampal neurons in the group, which the total concentration of AA and DHA was 4 ?mol/L, and the ratio AA∶DHA in medium was 2∶1 or 4∶1,were higher significantly than other groups and groups with other ratios of AA∶DHA. Conclusion: AA and DHA could promote the growth and development of hippocampal neurons in culture..

BACKGROUND:Digital three-dimensional reconstruction technology is gradually applied to orthopedic diseases with the advantages of visualization,accuracy and non-invasiveness,but there is less evidence-based support for its use in artificial hip hemiarthroplasty for intertrochanteric fractures of the femur in the elderly. OBJECTIVE:To investigate the application value and economic effects of digital three-dimensional reconstruction techniques in artificial hip hemiarthroplasty of intertrochanteric fractures of the femur in the elderly. METHODS:One hundred and thirty elderly patients with intertrochanteric femur fractures admitted to Zunyi First People's Hospital from January 2019 to December 2022 were selected and randomly divided into a control group(n=65)and an observation group(n=65).Artificial hip hemiarthroplasty was performed in both groups.The control group adopted the film template measurement method for manual preoperative planning while the observation group adopted a digital three-dimensional reconstruction technique.Preoperative planning and intraoperative actual application of prosthesis compliance rate,fibrinogen,D-dimer,bilateral femoral eccentric distance difference,bilateral lower limb length difference,Harris hip function score,visual analog scale score,excellent and good rate of hip function,complications,and hospitalization cost were observed in both groups. RESULTS AND CONCLUSION:(1)The proportion of acetabular side and femoral side prosthesis in grade 0(fully compliant)was higher in the observation group than that in the control group(P<0.05).(2)Fibrinogen and D-dimer levels in the observation group were lower than those in the control group 3 days after surgery(P<0.05).(3)The difference in bilateral femoral eccentric distance and the difference in bilateral lower limb length in the observation group were smaller than those in the control group immediately after surgery(P<0.05).The differences in Harris and visual analog scale scores were not significantly different between the two groups preoperatively,6 and 12 months postoperatively(P>0.05).There was no significant difference in excellent and good rate of hip function between the two groups 12 months postoperatively(P>0.05).(4)There was no significant difference in the complication rate between the two groups(P>0.05).The hospitalization cost of the observation group was higher than that of the control group(P<0.05).(5)It is indicated that digital three-dimensional reconstruction technology applied in artificial hip hemiarthroplasty of intertrochanteric femoral fracture in the elderly can not only accurately determine the prosthesis type before surgery,but also accurately reconstruct the bilateral lower limbs offline,but its hospitalization cost is high.