On the development of modular polyurethane-based bioelastomers for rapid hemostasis and wound healing

Massive hemorrhage may be detrimental to the patients,which necessitates the advent of new materials with high hemostatic efficiency and good biocompatibility.The objective of this research was to screen for the effect of the different types of bio-elastomers as hemostatic dressings.3D loose nanofiber sponges were prepared;PU-TA/Gel showed promising potential.Polyurethane(PU)was synthesized and electrospun to afford porous sponges,which were crosslinked with glutaraldehyde(GA).FTIR and 1H-NMR evidenced the successful synthesis of PU.The prepared PU-TA/Gel sponge had the highest porosity and water absorption ratio.Besides,PU-TA/Gel sponges exhibited cytocompatibility,negligible hemolysis and the shortest clotting time.PU-TA/Gel sponge rapidly induced stable blood clots with shorter hemostasis time and less bleeding volume in a liver injury model in rats.Intriguingly,PU-TA/Gel sponges also induced good skin regeneration in a full-thickness excisional defect model as revealed by the histological analysis.These results showed that the PU-TA/Gel-based sponges may offer an alternative platform for hemostasis and wound healing.

Regulation of nerve cells using conductive nanofibrous scaffolds for controlled release of Lycium barbarum polysaccharides and nerve growth factor

Currently,more and more patients suffer from peripheral nerve injury due to trauma,tumor and other causes worldwide.Biomaterial-based nerve conduits are increasingly recognized as a potential alternative to nerve autografts for the treatment of peripheral nerve injury.However,an ideal nerve conduit must offer topological guidance and biochemical and electrical signal transduction mechanisms.In this work,aligned conductive nanofibrous scaffolds comprising polylactic-co-glycolic acid and multiwalled carbon nanotubes(MWCNTs)were fabricated via coaxial electrospinning,and nerve growth factor(NGF)and Lycium barbarum polysaccharides(LBP)purified from the wolfberry were loaded on the core and shell layers of the nanofibers,respectively.LBP were confirmed to accelerate long-distance axon regeneration after severe peripheral nerve injury.In addition,the synergistic promotion of LBP and NGF on nerve cell proliferation and neurite outgrowth was demonstrated.MWCNTs were introduced into the aligned fibers to further increase the electrical conductivity,which promoted the directional growth and neurite extension of neurons in vitro.Further,the combination of conductive fibrous scaffolds with electrical stimulation that mimics endogenous electric fields significantly promoted the differentiation of PC12 cells and the axon outgrowth of neurons.Based on robust cell-induced behaviors,conductive composite fibers with optimized fiber alignment may be used for the promotion of nerve recovery.

Reduced graphene oxide supersonically sprayed on wearable fabric and decorated with iron oxide for supercapacitor applications

We demonstrate the fabrication of wearable supercapacitor electrodes.The electrodes were applied to wearable fabric by supersonically spraying the fabric with reduced graphene oxide(r GO)followed by decoration with iron oxide(Fe_(2)O_(3))nanoparticles via a hydrothermal process.The integration of iron oxide with r GO flakes on wearable fabric demonstrates immense potential for applications in high-energystorage devices.The synergetic impact of the intermingled r GO flakes and Fe_(2)O_(3) nanoparticles enhances the charge transport within the composite electrode,ultimately improving the overall electrochemical performance.Taking advantage of the porous nature of the fabric,electrolyte diffusion into the active r GO and Fe_(2)O_(3) materials was significantly enhanced and subsequently increased the electrochemical interfacial activities.The effect of the Fe_(2)O_(3) concentration on the overall electrochemical performance was investigated.The optimal composition yields a specific capacitance of 360 F g^(-1) at a current density of 1 Ag^(-1) with a capacitance retention rate of 89%after 8500 galvanostatic cycles,confirming the long-term stability of the Fe_(2)O_(3)/r GO fabric electrode.

Fabrication and characterization of Antheraea pernyi silk fibroin-blended P（LLA-CL） nanofibrous scaffolds for peripheral nerve tissue engineering

Electrospun nanofibers have gained widespreading interest for tissue engineering application. In the present study, ApF/P（LLA-CL） nanofibrous scaffolds were fabricated via electrospinning. The feasibility of the material as tissue engineering nerve scaffold was investigated in vitro. The average diameter increased with decreasing the blend ratio of ApF to P（LLA-CL）. Characterization of 13C NMR and FTIR clarified that there is no obvious chemical bond reaction between ApF and P（LLA-CL）. The tensile strength and elongation at break increased with the content increase of P（LLA-CL）. The surface hydrophilic property of nanofibrous scaffolds enhanced with the increased content of ApF. Cell viability studies with Schwann cells demonstrated that ApFIP（LLA-CL） blended nanofibrous scaffolds significantly promoted cell growth as compare to P（LLA-CL）, especially when the weight ratio of ApF to P（LLA-CL） was 25：75. The present work provides a basis for further studies of this novel nanofibrous material （ApF/P（LLA-CL）） in peripheral nerve tissue repair or regeneration.

The comparison of the Wnt signaling pathway inhibitor delivered electrospun nanoyarn fabricated with two methods for the application of urethroplasty

Urethral strictures were common disease caused by over-expression of extracellular matrix from fibroblast. In this study, we compare two nanoyarn scaffolds for improving fibroblasts infiltration without inhibition the over-expression of extracellular matrix. Collagenlpoly（L-lactide-co-caprolactone）（ColIP（LLA-CL）） nanoyarn scaffolds were prepared by conjugated electrospinning and dynamic liquid electrospinning, respectively, in addition, co-axial electrospinning technique was combined with the nanoyarn fabrication process to produce nanoyarn scaffolds loading Wntsignaling pathway inhibitor. The mechanical properties of the scaffolds were examined and morphology was observed by SEM. Cell morphology, proliferation and infiltration on the scaffolds were investigated by SEM, MTT assay and H＆E staining, respectively. The release profiles of different scaffolds were determined using HPLC. The results indicated that cells showed an organized morphology along the nanoyarns and considerable infiltration into the nanoyarn scaffolds prepared by dynamic liquid electrospinning （DLY）. It was also observed that the DLY significantly facilitate cell proliferation. The D-DLY could facilitate the infiltration of the fibroblasts and could be a promising scaffold for the treatment of urethra stricture while it may inhibit the collagen production.

A coupled catalyst composed of CoFe_(2)O_(4) magnetic nanoparticle and[HMIM]Br-FeCl_(3) to intensify the oxidative desulfurization of FCC diesel

Ionic liquids have been extensively studied as solvents or catalysts for oxidative desulfurization(ODS)of diesel fuel,but it is still a challenge to reduce the desulfurization time and steps.In this work,a new highly efficient desulfurization system composed of CoFe_(2)O_(4) magnetic nanoparticle,[HMIM]Br-FeCl_(3) and H_(2)O_(2) was developed for the ODS of FCC diesel fuel.The desulfurization performances were investigated including desulfurization time,temperature,volume ratio of IL/oil,O/S molar ratio,dosage of CoFe_(2)O_(4),FeCl_(3) content in ILs,regeneration,and reuse of catalyst and solvent.Owing to the coupled catalytic roles of CoFe_(2)O_(4) magnetic nanoparticle and[HMIM]Br-FeCl_(3),where Co2t and Fe3t interact with H_(2)O_(2) to produce ·OH radical that converts S-compounds into sulfone and sulfoxide compounds,such a desulfurization system is highly effective in removing S-compound in diesel fuel.The S-content in FCC diesel fuel was reduced from the original 272.8 ppm to 0.5 ppm with 99.82%S-removal efficiency after one step within 8 minunder the optimal conditions of 25℃,8 min,V(IL/oil)=1:10,O/S=20,5 wt%CoFe_(2)O_(4) dosage and n([HMIM]Br)/n(FeCl_(3))=1:1;the desulfurization performance is much better in desulfurization time and steps than other desulfurization systems reported previously.The desulfurization system can be regenerated and reused without remarkable loss of desulfurization activity.A desulfurization mechanism was proposed.