A nanofiber hydrogel derived entirely from ocean biomass for wound healing.

Crustaceans and fish scales in the marine food industry are basically thrown away as waste. This not only wastes resources but also causes environmental pollution. While reducing pollution and waste, biological activity and storage of materials are urgent issues to be solved. In this study, by first preparing dry fibers and then making hydrogels, we prepared a fish scale/sodium alginate/chitosan nanofiber hydrogel (FS-P) by cross-linking the nanofibers in situ. From fish and other organisms, fish gelatin (FG), collagen and CaCO3 were extracted. Fish scale (FS)/sodium alginate/chitosan nanofibers were cross-linked with copper sulfide nanoparticles prepared by a one-step green method to obtain FS-P nanofiber hydrogels under mild conditions without catalyst and additional procedures. These fiber hydrogels not only have good tissue adhesion and tensile properties, but also have the antibacterial effect of natural antibacterial and CuS photothermal synergism, which can achieve 51.32% and 49.96% of the antibacterial effect against Staphylococcus aureus and Escherichia coli respectively, avoiding the generation of superbacteria. The nanofiber hydrogels have 87.56% voidage and 52.68% degradability after 14 days. The combined strategy of using marine bio-based fibers to prepare gels promoted angiogenesis and tissue repair.

In situ melt electrospun polycaprolactone/Fe3O4 nanofibers for magnetic hyperthermia.

Magnetic fibrous membrane used to generate heat under the alternating magnetic field (AMF) has attracted wide attention due to their application in magnetic hyperthermia. However, there is not magnetic fibrous membrane prepared by melt electrospinning (e-spinning) which is a solvent-free, bio-friendly technology. In this work, polycaprolactone (PCL)/Fe3O4 fiber membrane was prepared by melt e-spinning and using homemade self-powered portable melt e-spinning apparatus. The hand-held melt e-spinning apparatus has a weight of about 450 g and a precise size of 24 cm in length, 6 cm in thickness and 13 cm in height, which is more portable for widely using in the medical field. The PCL/Fe3O4 composite fibers with diameters of 4-17 µm, are very uniform. In addition, the magnetic composite fiber membrane has excellent heating efficiency and thermal cycling characteristics. The results indicated that self-powered portable melt e-spinning apparatus and PCL/Fe3O4 fiber membrane may provide an attractive way for hyperthermia therapy.

[The adjuvant effect of chimeric flagellin fliC/esat].

AIM: To determine the role of ESAT-6 chimeric flagellin in TB immunology. METHODS: The coding sequences of flagellin of Salmonella typhimurium and ESAT-6 of Mycobacterium tuberculosis were cloned by PCR and identified by sequencing, respectively. Chimeric flagellin gene fliC/esat was constructed by overlap PCR technique. The ESAT-6 coding fragment was inserted to the hypervariable region of Salmonella flagellin gene fliCi. And then prokaryotic exprssion plasmids of pET-fliC/esat, pET-fliC and pBCX-esat were constructed and transformed into E.coli BL21(DE3), followed by induction of IPTG. The expressed proteins fliC/esat and ESAT-6 were identified by Western-blot assay using specific monoclonal antibody (mAb) HYB076-08. Bone marrow dendritic cells (BMDCs) were in vitro stimulated by fliC/esat and ESAT-6 proteins, and analyzed for the expression levels of CD40, CD80, CD86 and CD54 molecules. The secreted IL-12p70 was determined by ELISA. Moreover, C57BL/6 mice were immunized intravenously with fliC/esat or ESAT-6 protein. The specific IFN-γ-secreting cells and IL-4-secreting cells from the immunized mice were detected by ELISPOT assay using an ESAT-6 peptide as a stimulus. RESULTS: The results showed that the proteins of fliC/esat and ESAT-6 were expressed solubly, with the sizes of 64 kD and 39 kD respectively. Western blot analysis showed that both proteins reacted with the specific mAb against ESAT-6. BMDCs maturation was triggered by the chimeric flagellin fliC/esat. In contrast, ESAT-6 protein alone didn't activate BMDCs. IL-12p70 was also detected in the supernatants of BMDCs. The results showed that the chimeric flagellin fliC/esat induced significantly higher level of the secreted IL-12p70 than that of ESAT-6 protein. Furthermore, the chimeric flagellin fliC/esat significantly enhanced the Th1-biased immune responses against ESAT-6 in the immunized C57BL/6 mice. CONCLUSION: The chimeric flagellin we generated exerts Th1 type adjuvant activity for ESAT-6 protein.

[Preparation and characterization of monoclonal antibodies against chicken interferon-gamma].

AIM: To prepare monoclonal antibodies (mAb) against chicken interferon-gamma (ChIFN-gamma). METHODS: By using lymphocyte hybridoma technique, the inclusion body of the recombined bacteria, BL21(DE3) (pET-ChIFN-gamma), was harvested and used to immunize BALB/c mice. With the purified GST-ChIFN-gamma as detecting antigen, mAbs against ChIFN-gamma were prepared, and positive hybridoma clones were screened by indirect ELISA. The specificity of the mAb was characterized by indirect ELISA, Dot-ELISA and Western blot. RESULTS: Two hybridoma cell lines secreting mAbs against ChIFN-gamma named 1G5, 5E3 were obtained. The immunoglobulin subclasses of both 2 mAbs were IgG2a, and the ELISA titers of 2 mAbs ascitic fluids were 1:160,000, 1:12,000 respectively. In Dot-ELISA test, the 2 mAbs could only react with BL21 (DE3) (pET-ChIFN-gamma), BL21 (pGEX-6P-1-ChIFN-gamma), which expressed His-ChIFN-gamma, GST-ChIFN-gamma, respectively. Western blot analysis confirmed that the 2 mAbs could only react with GST-ChIFN-gamma and His-ChIFN-gamma proteins. CONCLUSION: Two mAbs specific to the protein of chicken interferon gamma are obtained, which may have important application value in further studies on immune detection, the functions of immune cells and immune regulation.