Synthesis and Characterization of Photo-Cross-Linkable Silk Fibroin Methacryloyl Hydrogel for Biomedical Applications.

Photo-cross-linkable hydrogels have recently gained increased interest in the field of biomedical applications. In this study, silk fibroin was derivatized with methacrylic anhydride (MA) to obtain silk fibroin methacryloyl (SFMA), forming hydrogel under UV light exposure in 1 min. The SFMA sol-gel transition did not involve significant structural change at the early stage. Then, the formation of the irreversible ß-sheet was confirmed after 24 h. The resulting SFMA hydrogel showed a homogeneous porous structure with pore sizes ranging from 400 to 700 µm, depending on the content. In addition, these hydrogels demonstrated a lower swelling capacity, higher rheological properties and compressive modulus, and slow degradation behavior at higher content, likely due to the higher degree of cross-linking. An experiment with cells indicated the good cell compatibility of these hydrogels, as revealed by Cell Counting Kit-8 (CCK-8) assays. As a tissue-engineered material, this photo-cross-linkable SFMA is expected to have a wide range of applications in the biomedical field.

Green process to prepare water-insoluble silk scaffolds with silk I structure.

Silk porous scaffolds have shown promising applications in tissue regenerations as cellular scaffolds to incorporate cells in vitro and in vivo, and facilitate cell proliferation and production of extracellular matrix. It remains strong needs to optimize the microstructures and performances of silk scaffolds for better biocompatibility. Here, a green process was developed to form water-insoluble scaffolds. Repeated freezing-dissolving procedures and silk nanofibers were introduced to tune the performances of the scaffolds, resulting in amorphous conformations and nanofibrous structures. Controllable degradation and mechanical properties as well as improved cell compatibility were then achieved for these scaffolds, suggesting their promising future in tissue regenerations. Our present results confirmed the possibility of actively designing silk scaffolds with preferable properties used in various tissue regenerations.

Identification of a pathogenic Aeromonas veronii isolated from rock carp, Procypris rabaudi / 中国人兽共患病学报

In June 2016,a disease among the cultured rock carp (Procypris rabaudi) in Yongchuan of Chongqing Municipality occurred.The aim of this study was to investigate biological characteristics and provide reference for Aeromonas veronii identification diagnosis and treatment.Pathogenic bacteria strain YY01 from the dying fishes were examined and isolated.Strain YY01's taxonomic status was identified by observing the morphology,studying the physiological and biochemical characters and sequencing the 16S rRNA and housekeeping gene gyrB.Its pathogenicity was checked by artificial infection experiment and virulence genes.Furthermore,effective medicine was detected by drug sensitivity.The 16S rRNA and gyrB gene sequence of the strain YY01 was more than 99％ homology with that of Aeromonas veronii,suggesting that the pathogen was Aeromonas veronii,which was also identified by the results of biochemical analysis.The LD50 of strain YY01 to rcok carp was 5.06 × 104 CFU/g.Four virulence genes were detected from YY01,including aerolysin (aer),hemolysin (Hly),Outer Membrane Protein Gene A (OmpA) and adhesion (Aha) genes.Antibiotic sensitivity assays showed that among 40 antibiotics tested,22 were sensitive and 11 were resistant.In conclusion,the strain YY01 is identified as Aeromonas veronii and it is proved to have strong pathogenicity.

Study of radius delayed union on bone mineral density and biomechanics treated by Chinese traditional medicine and bone marrow transplantation / 中国矫形外科杂志

[Objective]To study the effect of Chinese traditional medicine and bone marrow transplantation on treating delayed union.[Method]The model of delayed union in 75 rabbits was made and divided into 4 groups.Group A,20 rabbits treated with Chinese traditional medicine and red marrow 2 ml;Group B, 20 rabbits treated with Chinese traditional medicine;Group C,20 rabbits treated with red marrow;Group D,15 rabbits treated with nothing.X-ray in the 4th, 8th and 12th weeks were observed after treating.And bone mineral density and biomechanics were observed in 12~(th) week after trenting.[Result]X-ray revealed that group A heal earlier than group B,C and D.At the same time,bone mineral density and biomechanics in group A was better than others.[Conclusion]The treatment of delayed union by Chinese traditional medicine and bone marrow transplantation is one of effective means.

Treatment of rabbit's radius delayed union by Chinese traditional medicine and bone marrow transplantation / 中国矫形外科杂志

[Objective]To explore the effects of Chinese traditional medicine and bone marrow transplantation(BMT) on delayed union.[Method] The model of delayed union in rabbit's radius was made and divided into 4 gronps.Group A,20 rabbits treated with Chinese traditional medicine and red marrow 2 ml;Group B,20 rabbits treated with Chinese traditional medicine;Group C,20 rabbits treated with red marrow;Group D,15 rabbits treated with nothing.Histology,alkaline phosphates and xray were observed in the 4th,8th and 12th weeks after treating.[Result] Histology,alkaline phosphates and x-ray reveals that group A healed earlier than group B,C and D.At the same time,the rate of healing of group A was higher than others.[Conclusion] The treatment of delayed union by Chinese traditional medicine and bone marrow transplantation is an effective mean.