A functional PVA aerogel-based membrane obtaining sutureability through modified electrospinning technology and achieving promising anti-adhesion effect after cardiac surgery

Pericardial barrier destruction,inflammatory cell infiltration,and fibrous tissue hyperplasia,trigger adhesions after cardiac surgery.There are few anti-adhesion materials that are both functional and sutureable for pericardial reconstruction.Besides,a few studies have reported on the mechanism of preventing pericardial adhesion.Herein,a functional barrier membrane with sutureability was developed via a modified electrospinning method.It was composed of poly(L-lactide-co-caprolactone)(PLCL)nanofibers,poly(vinyl alcohol)(PVA)aerogel,and melatonin,named PPMT.The PPMT had a special microstructure manifested as a staggered arrangement of nanofibers on the surface and a layered macroporous aerogel structure in a cross-section.Besides providing the porosity and hydrophilicity obtained from PVA,the structure also had suitable mechanical properties for stitching due to the addition of PLCL nanofibers.Furthermore,it inhibited the proliferation of fibroblasts by suppressing the activation of Fas and P53,and achieved anti-inflammatory effects by affecting the activity of inflammatory cells and reducing the release of pro-inflammatory factors,such as interleukin 8(IL-8)and tumor necrosis factorα(TNF-α).Finally,in vivo transplantation showed that it up-regulated the expression of matrix metalloproteinase-1(MMP1)and tissue inhibitor of metalloproteinase-1(TIMP1),and down-regulated the expression of Vinculin and transforming growth factorβ(TGF-β)in the myocardium,thereby reducing the formation of adhesions.Collectively,these results demonstrate a great potential of PPMT membrane for practical application to anti-adhesion.

Preparation of High-precision Electrospun Nanoair Filter Paper for Air Purification

Electrospinning technology has become a research hotspot becauseof its advantages, such as simple operation, low cost, large specific surfacearea, high porosity, and good fiber continuity. Here, a new type of compositenanoair filter paper was prepared using electrospinning technology. Toimprove the practicability of air filter base paper, phenolic resin was used as acuring agent to improve the strength. The results show that the electrospunnanoair filter paper with air filter paper as the receiving substrate andpolyvinyl alcohol (PVA) solution as the spinning solution excellentlyperformed in all aspects. The influence of the thickness (spinning time) of thePVA nanofiber membrane on the micromorphology, physical properties, andfiltration performance of the electrospun nanoair filter paper was analyzed.According to the ISO 5011-2014 standard, the initial resistance, filtrationefficiency, mean pore size, and dust capacity of the electrospun nanoair filterpaper were 77.3 Pa, 99.9941%, 3.50 μm, and 146 g/m^(2), respectively, when thespinning time was 15 min.

Bead-like cobalt-nitrogen co-doped carbon nanocage/carbon nanofiber composite:A high-performance oxygen reduction electrocatalyst for zinc-air batteries

Proper regulation of metal-nitrogen carbon(M-N-C)materials derived from zeolitic imidazolate frameworks(ZIFs)is essential to enhance the oxygen reduction reaction(ORR)performance.However,most of the reports focus on the component regulation,and the structure regulation of ZIFs-derived M-N-C materials by a simple preparation method has been barely reported.Herein,using a one-step electrospinning method with subsequent pyrolysis,we have prepared a bead-like cobalt-nitrogen co-doped carbon nanocage/carbon nanofiber(Co-N-C/CNF)composite electrocatalyst with the porous carbon nanocages arranged one by one in the highly conductive carbon nanofibers.Profiting from the fully exposed active sites and improved conductivity,the Co-NC/CNF catalyst exhibits an excellent ORR performance even surpassing the commercial Pt/C catalyst.Density functional theory(DFT)results demonstrate that the CoNP-N1-C2 active sites on Co-N-C/CNF make the core contribution to the improvement of ORR properties.Moreover,the zinc-air battery(ZAB)based on the Co-N-C/CNF catalyst also shows outstanding discharge performance.This study provides a new strategy for the preparation and structural design for ZIFs-derived M-N-C materials as efficient ORR catalysts.