Papers by Author: Shen Zhou Lu

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Authors: Juan Wang, Gui Jun Li, Rui Jiang, Zhu Ping Yin, Shen Zhou Lu
Abstract: A method was developed to prepare the Antheraea Pernyi silk fibroin (ASF) microspheres using lysozyme as a model drug to estimate the application of ASF in drug controlled release field. The structure of ASF microsphere carried drug was characterized by X-ray diffraction and FTIR. The morphology and the influence of the microspheres on the degradation of lysozyme were investigated using scanning electron microscope. The results show that encapsulation rate was increased and drug content was decreased with the addition of lysozyme increasing. In vitro release of lysozyme from the ASF particles we demonstrated that the release kinetics depends on the pH. The pH played important roles in controlling lysozyme release profiles. It also can be seen that the degradation speed of lysozyme ASF microspheres slightly larger than the pure ASF microspheres.
Authors: Shen Zhou Lu, Juan Wang, Li Mao, Gui Jun Li, Jian Jin
Abstract: Silk nanoparticles were easily obtained from regenerated Antheraea Pernyi Silk Fibroin (ASF). The morphology and average size of the silk particles was sensitive to pH value of fibroin solution. The diameter of nanoparticles prepared was in the range of 30 nm to 1000 nm with a narrow size distribution. On this process, the molecular conformation of regenerated ASF changed from α-helix to β-sheet structure. The shape of prepared nanoparticles were regular spherical structure when the pH value was about 4.3 (pI) in ASF solution. Doxorubicin hydrochloride (DOX) was loaded in the ASF particles as drug release model and the drug-loading ratio was 3.4 %. The release rate of DOX from ASF nanoparticles was pH sensitive. After 23 days release, there was still 84% DOX in the ASF nanoparticles. The result suggested that the ASF nanoparticles might be suitable microcarriers for drug delivery.
Authors: Shan Shan Zhang, Jiao Jiao Li, Xiao Feng Zhang, Shen Zhou Lu
Abstract: Corneal transplantation is the only effective way to repair the damaged corneal tissue and solve the problem of insufficient donor cornea and immune rejection. Biocompatibility and stable transparent are necessary conditions of corneal stromal cells carrier. In this paper, the acetamide/silk (AC/SF) composite membranes are studied to be applied in corneal repair material. AC/SF membranes with different blending proportions had stable transparency, good cell compatibility. X-ray diffraction was used to investigate the structure of the composite films. The acetamide inhibited the formation of large crystalline particles, changed the crystal structure of silk fibroin and made the random coil structure convert to Silk I or Silk II. Therefore, acetamide was not only crosslinking agent but also crystallization inhibitor. The corneal stromal cells were seeded on sterilized composite membranes. After 5 h, the adhesion rate of stromal cells was more than 90%, cell could proliferate regularly on the composite membrane. There was no obvious difference in contrast to control plate. These results demonstrated that the composite membrane could promote corneal stromal cell proliferation.
Authors: Wei Wei Xu, Jian Bing Liu, Ming Zhong Li, Shen Zhou Lu, Miao Liang Luo
Abstract: The gradient silk fibroin (SF)/ hydroxyapatite (HA) porous composite used for the scaffold of cartilage-bone tissue regeneration was prepared with SF powder and HA powder by layer-by-layer mould pressing method and granular NaCl as porogent. The characteristics were performed by Electron Microprobe and Energy Dispersive Spectometer (EDS). It indicated that the distribution of SF and HA presented linear gradient along the thickness direction in the materials. The porosity of composites increased with NaCl content increasing, while the density decreased. As the result of mechanical properties measurement, the bending strength and compressive strength decreased with NaCl content increasing. Compared the mechanical properties between gradient material and non-gradient material, it indicated that bending strength of gradient SF/HA porous material was higher than non-gradient SF/HA porous material’s.
Authors: Jiao Jiao Li, Shan Shan Zhang, Xin Yue Zhang, Shen Zhou Lu
Abstract: To improve the properties of silk fibroin film, the silk fibroin/pyrrolidone blend films were prepared by mixing silk fibroin and pyrrolidone solution at different ratios. The structure and mechanical properties of blend films were characterized. X-ray diffraction was used to investigate structure of the SF/PYR films, and the results indicated that the blend films were composed of the β-sheet form. Tensile strength and elongation at break of blend films were measured using an instron tensile tester. The results showed that tensile strength and elongation at break of blend films were high enough for application. Furthermore, the films’ flexibility was significantly improved. The optical clarity of blend film was tested by Microplate system. It can be seen from the results that optical clarity is not stable, but in some particular ratios we also can get high light transmittance blend films. At last, biocompatibility of blend films (the rate of the blend film is 30%) was accessed with L929 cell. The results showed that all types of blend films were able to support cell adhesion and proliferation. In addition, the cellular morphology of the cells cultured on blend films was better than that on silk fibroin films. In view of the mechanical properties and optical clarity, combined with their ability to support L929 proliferation suggests that this blend films will offer new options in many different biomedical applications.
Authors: Rui Juan Xie, Ming Zhong Li, Shen Zhou Lu, Wei Hua Sheng, Yu Feng Xie
Abstract: Bombyx mori Sericin films were prepared with PEG-DE as cross linking agent. The main physical properties, structure characteristics, cytotoxicity and cell proliferation of sericin films were measured and analyzed. The result showed that sericin films prepared by cast method containing 30-40% of PEG-DE, showed good mechanical properties. PEG-DE caused the changes of the condensed structure of sericin films. The films prepared from sericin extracted both from silk-gland and cocoon shell showed good cytocompatibility. Silk sericin films with PEG-DE had no obvious cytotoxicity to cells.
Authors: Min Qing Luo, Cen Cen Zhang, Shen Zhou Lu
Abstract: The transparent water-insoluble silk fibroin(SF) films were casted from the mixture solution of silk fibroin and xylitol/mannitol. The structure, surface morphology, solubility, mechanical properties and light transmittance of the blend films were measured. FT-IR, X-ray diffraction retuslts indicated that the films were mainly composed of Silk I structure. SEM showed the blend films with xylitol were miscible, whereas the blend films with mannitol had phase-separated structure. There were lots of nanopores in the blend films in the wet state. The insoluble SF /xylitol films had excellent mechanical properties while the SF / mannitol films were brittle. The mechanical property of SF/alcohol blend films were consistent with the human cornea in wet state.When the contents of xylitol were 10% and 20%, the blend films had high light transmittance which were similar to human cornea. In summary, the SF /xylitol film containing 10% xylitol provides a great potential to act as repairing materials for cornea.
Authors: Shen Zhou Lu, Li Mao, Yu Liu, Shan Sun, Gui Jun Li
Abstract: Antheraea pernyi silk fibroin (ASF) solution was prepared by dissolving Antheraea pernyi silk fiber in lithium thiocyanate solution. The ASF/glycol blend films were prepared by casting aqueous solution of ASF mixed with glycol. The structure of blend film was investigated by the X-ray diffraction method and infrared spectroscopy. The result showed that the structure of regenerated ASF film was α-helix and random coil conformation. After mixing with glycol, it resulted in significant increase in β-sheet structure with the improvement of water resistance of the films. This effect was strongly dependent on glycol content in the blend film. When the glycol content was more than 45 wt%, the structure of ASF changed to β-sheet and the film became water-insoluble. The breaking strength and elongation of ASF/glycol blend film were 30 Mpa and 50 %, respectively. In summary, the ASF/glycol blend film provided a great potential as a biological material.
Authors: Shen Zhou Lu, Xi Long Wu, Min Qing Luo
Abstract: Silk hydrogels have mechanical properties and structural features that are similar to load-bearing soft tissues, and can be implanted for tissue restoration. In the present study, we investigate silk fibroin sol-gel transition processes in detail. The effect of different surfactants and high temperature pretreatment were studied detailedly. Based on the study, a mechanism was summarized. The result showed that the surfactant accelerated sol-gel transitions while heat pretreatment decelerated sol-gel transitions. Gelation time was decreased to several hours when added surfactant with negative charge. On the contrary, gelation time was increased to dozens of days when extended the time of high-temperature processing. Upon gelation, a random coil structure of the silk fibroin was transformed into a β-sheet structure.
Authors: Gui Jun Li, Juan Wang, Shan Sun, Shen Zhou Lu
Abstract: A new method was developed to prepare the Antheraea Pernyi silk fibroin (ASF) microspheres and rhodamine was as a model drug. The structure of ASF microsphere carried drug was β-sheet structure characterized by X-ray diffraction and FTIR. The morphology of microspheres was observed by scanning electron microscope. The diameter of the ASF particles was not changed before and after drug carried. It was in the range of 1 μm to 5μm with a narrow size distribution. The encapsulation rate, drug content, and the drug release were tested. The resulted showed that encapsulation rate was increased and drug content was decreased with the addition of rhodamine increasing. The drug released 70% after 12 days and there was no significant difference with different pH value.
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