Core fucosylation and its roles in gastrointestinal glycoimmunology

Glycosylation is a common post-translational modification in eukaryotic cells.It is involved in the production of many biologically active glycoproteins and the regulation of protein structure and function.Core fucosylation plays a vital role in the immune response.Most immune system molecules are core fucosylated glycoproteins such as complements,cluster differentiation antigens,immunoglobulins,cytokines,major histocompatibility complex molecules,adhesion molecules,and immune molecule synthesis-related transcription factors.These core fucosylated glycoproteins play important roles in antigen recognition and clearance,cell adhesion,lymphocyte activation,apoptosis,signal transduction,and endocytosis.Core fucosylation is dominated by fucosyltransferase 8(Fut8),which catalyzes the addition ofα-1,6-fucose to the innermost GlcNAc residue of N-glycans.Fut8 is involved in humoral,cellular,and mucosal immunity.Tumor immunology is associated with aberrant core fucosylation.Here,we summarize the roles and potential modulatory mechanisms of Fut8 in various immune processes of the gastrointestinal system.

Influence of Teflon Substrate on Crystallization and Enzymatic Degradation of Polymorphic Poly(butylene adipate)

Oriented and non-oriented Teflon films, which were found to have the same crystalline structure, but different surface morphologies, were used to sandwich poly（butylene adipate） （PBA） films during isothermal crystallization. It was found that both the Teflon surface structure and the PBA polymorphic structure are the determining factors to induce epitaxial crystallization. The oriented Teflon film was able to induce epitaxial crystallization of PBA α crystal, while the non-oriented Teflon did not induce any epitaxial crystallization of PBA. Epitaxial crystallization did not occurred for PBA β crystals between neither the oriented nor the non-oriented Teflon films. The enzymatic degradation rate of PBA films was not determined by the epitaxial crystallization, in fact it was still dependent on the polymorphic crystal structure of PBA. The morphological changes of PBA films after enzymatic degradation confirmed again that the epitaxial crystallization only occurred for the PBA film with α crystal structure which was produced by being sandwiched between oriented Teflon films, and it happened only on the surface of PBA films.

Fully Biodegradable Poly(lactic acid)/Poly(propylene carbonate)Shape Memory Materials with Low Recovery Temperature Based on in situ Compatibilization by Dicumyl Peroxide

Fully biodegradable blends with low shape memory recovery temperature were obtained based on poly（lactic acid）（PLA） and poly（propylene carbonate）（PPC）. By virtue of their similar chemical structures, in situ cross-linking reaction initiated by dicumyl peroxide（DCP） between PLA and PPC chains was realized in PLA/PPC blends. Therefore, the compatibility between PLA and PPC was increased, which obviously changed the phase structures and increased the elongation at break of the blends. The compatibilized blends had a recovery performance at 45 °C. Combining the changes of phase structures, the mechanism of the shape memory was discussed. It was demonstrated that in situ compatibilization by dicumyl peroxide was effective to obtain eco-friendly PLA/PPC blends with good mechanical and shape memory properties.