Compatibility Evaluation of Non-Woven Sheet Composite of Silk Fibroin and Polyurethane in the Wet State.

SF/polyurethane composite non-woven sheet was fabricated to evaluate the cardiovascular tissue engineering materials in the wet state. The compatibility and microstructure analyses were carried out on the fabricated SF/polyurethane composite non-woven sheet by thermal analysis and solid-state NMR analysis in the wet state. To evaluate the modulus of elasticity, a tensile test was performed and supported with dynamic viscoelasticity and mechanical analysis. Results showed that SF/polyurethane composites form domains within the non-woven sheet and are in a finely dispersed state while maintaining their structures at a scale of several tens of nm. Moreover, an increase of the loss tangent with low elastic modulus proved that a micromolecular interaction occurs between silk fibroin (SF) and polyurethane molecules.

Silk fibroin-Pellethane® cardiovascular patches: Effect of silk fibroin concentration on vascular remodeling in rat model.

Life-threatening cardiovascular anomalies require surgery for structural repair with cardiovascular patches. The biomaterial patch, derived from Bombyx mori silk fibroin (SF), is used as an alternative material due to its excellent tissue affinity and biocompatibility. However, SF lacks the elastomeric characteristics required for a cardiovascular patch. In order to overcome this shortcoming, we combined the thermoplastic polyurethane, Pellethane® (PU) with SF to develop an elastic biocompatible patch. Therefore, the purpose of this study was to investigate the feasibility of the blended SF/PU patch in a vascular model. Additionally, we focused on the effects of different SF concentrations in the SF/PU patch on its biological and physical properties. Three patches of different compositions (SF, SF7PU3 and SF4PU6) were created using an electrospinning method. Each patch type (n = 18) was implanted into rat abdominal aorta and histopathology was assessed at 1, 3, and 6 months post-implantation. The results showed that with increasing SF content the tensile strength and elasticity decreased. Histological evaluation revealed that inflammation gradually decreased in the SF7PU3 and SF patches throughout the study period. At 6 months post-implantation, the SF7PU3 patch demonstrated progressive remodeling, including significantly higher tissue infiltration, elastogenesis and endothelialization compared with SF4PU6. In conclusion, an increase of SF concentration in the SF/PU patch had effects on vascular remodeling and physical properties. Moreover, our blended patch might be an attractive alternative material that could induce the growth of a neo-artery composed of tissue present in native artery.

The effect of a silk Fibroin/Polyurethane blend patch on rat Vessels.

Patch grafts are widely used in various kind of vascular surgeries such as detect repair or dilation of vascular stenosis. Expanded polytetrafluoroethylene (ePTFE) patches are flexible and handle well, but have shown problems with calcification as they are non-bioabsorbable and therefore permanently remain in the body. It is important to develop an alternative biocompatible patch. Silk fibroin (SF) was developed as a biocompatible material, but it lacks of the elasticity required for surgery as a patch. Polyurethane (PU) is also a well-known elastomer so this study focused on the SF and the PU blend materials with a weight ratio of 5:5 (SF/PU). To evaluate the SF/PU patch, the patches were implanted into the abdominal aortas of rats, using the ePTFE patch in the control group. Because it was more flexible the SF/PU patch was easier to implant than the ePTFE patch. At 1 week after implantation, the SF/PU patch had been infiltrated with cells and collagen fiber. The ePTFE control patch did not accumulate collagen fiber until 3 months and calcification occurred at 4 weeks. The SF/PU patch did not present any signs of calcification for 3 months. This study addressed the problems associated with using SF in isolation and showed that the SF/PU patch can be considered as a useful alternative to the ePTFE to overcome the problem of calcification.

Recombinant Measles AIK-C Vaccine Strain Expressing the prM-E Antigen of Japanese Encephalitis Virus.

An inactivated Japanese encephalitis virus (JEV) vaccine, which induces neutralizing antibodies, has been used for many years in Japan. In the present study, the JEV prM-E protein gene was cloned, inserted at the P/M junction of measles AIK-C cDNA, and an infectious virus was recovered. The JEV E protein was expressed in B95a cells infected with the recombinant virus. Cotton rats were inoculated with recombinant virus. Measles PA antibodies were detected three weeks after immunization. Neutralizing antibodies against JEV developed one week after inoculation, and EIA antibodies were detected three weeks after immunization. The measles AIK-C-based recombinant virus simultaneously induced measles and JEV immune responses, and may be a candidate for infant vaccines. Therefore, the present strategy of recombinant viruses based on a measles vaccine vector would be applicable to the platform for vaccine development.

Numerical investigation of side emission from large-area vertical-cavity surface-emitting lasers.

For large-area ion-implanted vertical-cavity surface-emitting lasers (VCSELs), side emission from the edges of a chip disturbs the laser emission of a VCSEL mode, and suppression of it is fundamental. In this paper, we present results of a numerical investigation of the side emission from large-area VCSELs. We have modeled a VCSEL structure by an infinitely broad layer structure with mirror loss at the edge surfaces. Estimated threshold gains indicate that laser emission occurs either in a VCSEL mode or in an edge-emitting Fabry-Perot (EEFP) mode. Calculated emitter length dependence of the threshold gain of these modes shows good agreement with experimental results, and the side emission is verified to be the laser emission of the EEFP mode. We have also discussed the way to suppress the side emission and confirmed that our recent achievement of over 200 W quasi-continuous-wave output from an ion-implanted VCSEL array is due to antireflection coatings of the edges and introduction of optical losses in ex-emitter regions.

High power density vertical-cavity surface-emitting lasers with ion implanted isolated current aperture.

We report on GaAs-based high power density vertical-cavity surface-emitting laser diodes (VCSELs) with ion implanted isolated current apertures. A continuous-wave output power of over 380 mW and the power density of 4.9 kW/cm2 have been achieved at 15 °C from the 100-µm-diameter aperture, which is the highest output characteristic ever reported for an ion implanted VCSEL. A high background suppression ratio of over 40 dB has also been obtained at the emission wavelength of 970 nm. The ion implantation technique provides an excellent current isolation in the apertures and would be a key to realize high power output from a VCSEL array.

Anti-arthritic activity of synthesized chondroitin sulfate E hexasaccharide.

The purpose of this study was to investigate the anti-arthritic effects of synthesized chondroitin sulfate E hexasaccharide (sCSE-6, CAS 866407-73-0), using a type II collagen-induced arthritis model in mice. sCSE-6 was administered subcutaneously on a daily basis to type II collagen (CII)-sensitized mice from day 0 to day 55. The severity of arthritis, as well as the immunohistological features of the arthritic mice, were analyzed. sCSE-6 inhibited the course of arthritis and restored the body weight loss of CII-immunized mice. An immunohistological analysis showed that bone/cartilage destruction in the arthritic mice was significantly attenuated by sCSE-6 treatment, with a marginal inhibition of synovial inflammation also observed. The beneficial effect of sCSE-6 on bone destruction, which is the most important factor in preventing arthritis, is particularly noteworthy. In summary, sCSE-6 inhibited arthritis and helped to prevent bone and cartilage destruction in a type II collagen-induced arthritis model in mice. The findings indicated that CSE oligosaccharides might be a novel potential therapeutic tool for rheumatoid arthritis.

Development of a fully automated macromolecular crystallization/observation robotic system, HTS-80.

A robotic system has been developed to be used for macromolecular crystallization and observation in typical university laboratories with a research focus on protein crystallography. The system consists of three major parts: a dispenser unit, a storage unit and an observation unit. This system is designed to automatically perform all of the processes involved in crystallization and observation without requiring any manual operations. The dispenser and observation units can carry out both sitting-drop vapor-diffusion procedures and microbatch procedures. With this system, the procedures are controlled by a personal computer running GUI-based software. After the dispensing of protein solution into the crystallization plates, they are automatically transferred to the storage units, followed by automatic observation according to a required schedule with arbitrary intervals. At each stage of crystallization, droplets in the crystallization plates are examined by original image-processing software in order to evaluate the appearance of the crystals.

IgA nephropathy associated with X-linked thrombocytopenia.

X-Linked thrombocytopenia (XLT) is characterized by congenital thrombocytopenia with small platelets and absence of immunodeficiency; XLT is an allelic variant of Wiskott-Aldrich syndrome (WAS). Both entities are caused by mutations in the same gene. This study presents the case of an 8-year-old boy with XLT. He developed immunoglobulin A (IgA) nephropathy at the age of 4 years. Genetic analysis confirmed the XLT diagnosis. His maternal uncle also had thrombocytopenia from early infancy and developed end-stage renal failure as a result of IgA nephropathy. The maternal uncle was inferred to be affected with XLT because of the carrier status of the patient's mother. Abnormal glycosylation has a role in pathogenesis in IgA nephropathy; moreover, sialophorin glycosylation is defective in WAS. Altered glycosylation may contribute to renal involvement in patients with WAS/XLT despite different defective glycosylation patterns in IgA nephropathy and WAS/XLT.

End-stage renal failure in a child with X-linked ichthyosis.

We describe an 8-year-old boy who presented with steroid-resistant nephrotic syndrome (SRNS) associated with X-linked ichthyosis (XLI). At birth, the patient exhibited scaly skin, cryptorchidism, and steroid sulfatase (STS) deficiency. DNA analysis showed deletion of exons 1-10 of the STS gene. Proteinuria developed at 6 years and was resistant to steroid therapy. Kidney biopsy findings prior to steroid therapy were compatible with minimal change nephrotic syndrome. By immunofluorescence, glomerular basement membranes exhibited diffuse linear staining for the alpha5 chain of collagen IV, making X-linked Alport syndrome an unlikely explanation for the association of SRNS and ichthyosis. Despite immunosuppressive therapy together with oral prednisolone, no clinical response was achieved. He rapidly reached end-stage renal failure and finally underwent renal transplantation. We propose that SRNS should be considered as one of the highly variable phenotypes associated with XLI.