BACKGROUND:Silk fibroin as natural biological macromolecules has good biocompatibility, but it is difficult to make the three-dimensional scaffold with uniform structure because of its higher crystalization performance and bigger brittleness. OBJECTIVE:To improve the crystalization of silk fibroin through the addition of chitosan, and to get three-dimensional tissue engineering scaffolds with better mechanical strength. METHODS: CaCl2/CH3CH2OH/H2 RESULTS AND CONCLUSION:The introduction of chitosan could improve the properties of scaffolds. The porosity of the composite scaffold with lower porosity was more uniform and orderly with higher content of O ternary solution was used to dissolve silkworm cocoon to extract silk fibroin and form solution. Silk fibroin solution and chitosan solution were mixed according to different mixing ratios of 2:1, 1:1, 1:2, respectively, and then porous silk protein/chitosan scaffolds were prepared by freeze-drying method and treated by methanol. Scaffold morphology was observed by scanning electron microscopy, the chemical structure and crystaline state of the scaffolds were characterized through infrared spectrum and X-ray diffraction test, respectively. Also, the porosity and water uptake were tested and periodic cycle compression mechanical properties under the water environment were determined. chitosan. When the mixture rate of chitosan and silk fibroin was 1:2, the water uptake rate was the highest in the composite scaffolds, and also higher than that of the silk fibroin scaffold but lower than that of the chitosan scaffold. With the increase of silk fibroin, the composite scaffolds had better elasticity and stronger ability to maintain the shape.

The curcumin prodrugs, which could be selectively activated in tumor cells, were prepared to establish a basis for the targeted chemotherapy for cancer. On the basis of the molecular structure of curcumin, the N-maleoyl-L-valine-curcumin (NVC), N-maleoyl- glycine-curcumin (NGC) were chemically synthesized and identified by IR and NMR spectroscopy. After treatment with these two prodrugs for 6 - 24 h, the rates of growth inhibition on human bladder cancer EJ cells and renal tubular epithelial (HKC) cells were detected by MTT colorimetry. Our results showed that after the treatment with 20 micromol/L - 40 micromol/L NVC and NGC for 6 - 24 h, the growth inhibitory effects on EJ cells were 6.71% - 65.13% (P < 0.05), 10.96% - 73.01% (P < 0.05), respectively, in both dose- and time-dependent manners. When compared with the curcumin of same concentrations, the growth inhibitory effects of these two prodrugs on HKC cells were significantly decreased (P < 0.01). It is concluded that activation of curcumin prodrugs via hydrolysis functions of cellular esterase could inhibit the growth activities of tumor cells, and reduce the side effects on normal diploid cells. This provided a novel strategy for further exploration of tumor-targeted chemotherapeutic drugs.
Antineoplastic Agents, Phytogenic/*pharmacology ; Curcumin/*pharmacology ; Dose-Response Relationship, Drug ; Prodrugs/*chemical synthesis ; Prodrugs/*pharmacology ; Tumor Cells, Cultured ; Urinary Bladder Neoplasms/*pathology

The curcumin prodrugs, which could be selectively activated in tumor cells, were prepared to establish a basis for the targeted chemotherapy for cancer. On the basis of the molecular structure of curcumin, the N-maleoyl-L-valine-curcumin (NVC), N-maleoyl- glycine-curcumin (NGC) were chemically synthesized and identified by IR and NMR spectroscopy. After treatment with these two prodrugs for 6-24 h, the rates of growth inhibition on human bladder cancer EJ cells and renal tubular epithelial (HKC) cells were detected by MTT colorimetry. Our results showed that after the treatment with 20 μmol/L- 40 μmol/L NVC and NGC for 6 - 24 h, the growth inhibitory effects on EJ cells were 6.71% -65.13 % (P＜0.05), 10.96 % -73.01% (P ＜0.05), respectively, in both dose- and time-dependent manners. When compared with the curcumin of same concentrations, the growth inhibitory effects of these two prodrugs on HKC cells were significantly decreased (P＜0.01). It is concluded that activation of curcumin prodrugs via hydrolysis functions of cellular esterase could inhibit the growth activities of tumor cells, and reduce the side effects on normal diploid cells. This provided a novel strategy for further exploration of tumortargeted chemotherapeutic drugs.

Objective To investigate the training expectations and training strategies of orthopedic clinical specialist nurses (OCSN).Methods Totally 5 020 orthopedic nurses from 342 hospitals from 30 provinces and cities were selected bv convenience sampling.Participants were investigated hy WeChat platform with self-designed questionnaire.Results A total of 4 982 effective questionnaires were collected.Among investigated nurses,13.7％ of them received orthopedic specialist nurses training;91.4％ believed that training should be carried out.Qualifications should be:college degree and above,senior nurse and above,at least 3 ～5 years of nursing experience,1～3 years of nursing experience in orthopedic department.For curriculum,public courses expected to be arranged were communieation skills,nursing teaching,nursing management,and nursing research;expected professional courses were functional exercises,pain management,extremity injury nursing,common treatment techniques in orthopedic department,traction nursing,and position nursing.It was suggested that training was divided into subspecialties and off-duty;classroom teaching,teaching rounds,case discussion and experience exchange were expected training methods;"theory-practice-theory-practice" was most preferable traiuing mode.The preferred teachers were orthopedic doctors,orthopedic head nurses,orthopedic specialist nurses,and senior orthopedic nurses.The length of training was expected to be three months,time for clinical practice should be greater than or equal to theoretical teaching,and the practice bases should be tertiary hospitals.Evaluation should be performed before completion,recertification could be later than completion,and the interval time of recertification should be within 5 years.Conclusion Training needs of orthopedic nurses for OCSN are strong.Training expectations(contents,length,modes and teachers) of orthopedic nurses should be considered when designing systematic training program on OCSN.