Preparation of Nested g-C3N4 Fiber Surrounding Graphene Oxide and Its Photocatalytic Degradation of Rhodamine B.

g-C3N4 and graphene oxide (GO) are simultaneously introduced into electrospun polyacrylonitrile (PAN) nanofibers to form a nested structure. By Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS), g-C3N4 has been perfectly introduced into the PAN@GO nanofiber membrane and affects the porosity of the fiber itself. Comparison of nested electrospinning PAN/PAN@GO and different proportions of PAN@g-C3N4/PAN@GO nanofibers has a different effect on reducing the concentration and absorption of rhodamine B (RhB) dye in the visible region. Combined with the advantages of g-C3N4 and GO and the performance of fibers in the photocatalytic process, the optimal nested PAN@g-C3N4/PAN@GO nanofibers were selected. These results indicate that the nested PAN@g-C3N4/PAN@GO nanofibers with high photocatalytic activity have great potential in the treatment of printing and dyeing wastewater.

Deciphering the Adsorption Behavior of Volatile Organic Compounds with Electrospun Polyacrylonitrile/Molecular Sieve Nanocomposites.

In this study, a new type of molecular sieve/polyacrylonitrile fiber (M-PAN) was prepared by electrospinning to adsorb atmospheric volatile organic compounds (VOCs). The suitable content of molecular sieve in nanocomposites was also determined for achieving maximum VOCs adsorption capacity. SEM, TEM and N2 adsorption/desorption analyzer were performed for characterization of the surface morphology, structural properties, surface area and pore size. A part of molecular sieve is exposed on the fiber surface where VOCs can be adsorbed efficiently in a short time. Acetone was used as a challenge pollutant to evaluate the adsorption of VOCs at different recycling times and types of electrospinning nanofibers. The adsorption capacity of 6M-PAN (60% weight of molecular sieve) nanofiber reached 58.2 µg g-1 and the reused nanofibers nearly had the same adsorption capacity as the newly prepared nanofibers after several times of recirculation.

Improved immunogenicity of a self tumor antigen by covalent linkage to CD40 ligand.

The interaction between the CD40 ligand (CD40L) and CD40 on antigen-presenting cells (APCs) is critical in promoting humoral and cellular immune responses. Agonistic anti-CD40 monoclonal antibody and soluble CD40L can act as powerful adjuvants to promote vaccination, but usually require repeated high-dose treatment. In this study, we demonstrate that the adjuvant effect of CD40L can be greatly improved by directly linking the antigen to CD40L. We constructed a fusion protein (Id-CD40L) consisting of the extracellular domain of CD40L and the idiotype (Id) protein, a weakly immunogenic tumor-specific antigen derived from the murine 38C13 B-cell lymphoma. The soluble Id-CD40L fusion protein retained CD40 binding activity and stimulated CD80 and CD86 upregulation and interleukin (IL)-12 production by macrophages. Immunization of mice with Id-CD40L without adjuvants resulted in high titers of anti-Id Abs dominated by the IgG1 isotype and protected the mice from subsequent lethal tumor challenge. In a dose-response study, we demonstrated that Id-CD40L elicited anti-Id antibody (Ab) responses in all immunized animals, even at a dose as low as 0.5 microg. Immunization with free Id and an IgG-CD40L fusion protein, which was identical in structure to Id-CD40L but lost the Id determinant, resulted in significant lower anti-Id responses, indicating that physical linkage between the tumor antigen and CD40L was required for the optimal immune response. These results demonstrate that fusing CD40L to a candidate antigen can greatly improve the adjuvant activity of CD40L. This approach may be useful in developing vaccines for a variety of malignant and infectious diseases.