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Macrophage M2 polarization is one of the most important processes for promoting diabetic wound healing, but how chirality regulates this process is still unknown. Thus, chiral hydrogels based on amino acid derivatives (L-Fmoc-NV and D-Fmoc-NV) were applied to investigate the influence of chirality on macrophage M2 polarization. Compared to the right-handed nanofibers of D-Fmoc-NV, the left-handed helical nanofibers of L-Fmoc-NV can significantly affect the polarization of macrophages towards the M2 phenotype. Furthermore, the left-handed helical nanofibers of L-Fmoc-NV can more significantly promote cell adhesion, proliferation, and antibacterial responses than the nanofibers of D-Fmoc-NV. Based on these advantages of the left-handed helical nanofibers of L-Fmoc-NV, a more expedited healing trajectory (∼14 days) was observed in the L-Fmoc-NV systems. This work offers a new approach for chronic diabetic wound healing via the chirality-induced polarization of macrophages towards the M2 phenotype. [ABSTRACT FROM AUTHOR]

Thermal evaporation can significantly facilitate scalable, uniform, and conformal perovskite film, particularly well‐suited for the preparation of perovskite/silicon (Si) tandem solar cells. However, the perovskite material easily induces a phase transition from a photoactive phase to a photoinactive phase, limiting the development of the stability and efficiency of tandem cells. Introducing lead chloride (PbCl2) into wide‐bandgap perovskite materials is beneficial for the fabrication of efficient and stable light‐absorbing materials, but the microscopic mechanism of the effect of PbCl2 on perovskite is still unclear. The study here reports evidences that the addition of PbCl2 to improve perovskite film stability and optoelectronic performance is due to the minor octahedral tilting of the perovskite structure are reported. It also demonstrates that this strategy accelerates interfacial charge transfer and carrier diffusion in the perovskite bulk and heterojunction interfaces. Therefore, the wide‐bandgap perovskite solar cells (PSCs) prepared by adding PbCl2 exhibit a champion power conversion efficiency (PCE) of 17.80%. The PSCs retain 97% of their performance following 200 h of operation at the maximum power point under full 1‐sun illumination. Finally, monolithic perovskite/Si tandem cells with record PCEs of 27.43% and an open‐circuit voltage of 1.817 V are fabricated. [ABSTRACT FROM AUTHOR]

Ursolic acid has gradually attracted much attention due to its unique pharmacological activities and valuable market value in recent years. Currently, ursolic acid is mostly extracted from loquat leaves, but the plant extraction method has low yield and high cost, and chemical synthesis is not readily available, so the biosynthesis method provides a new source for ursolic acid. α-amyrin acts as the main precursor for the synthesis of ursolic acid, and its yield is positively correlated with ursolic acid yield. Oxidosqualene cyclase(OSC) belongs to a multigene family which can catalyze the common precursor 2,3-oxidosqualene to generate different types of triterpene backbones, and plays a decisive role in the synthesis of triterpenoids. However, there are fewer reported key genes catalyzing the synthesis of α-amyrin in medicinal plants, and the yield and proportion of α-amyrin in the catalyzed products have always been a focus of research. In this study, ItOSC2, MdOSC1, AaOSC2 and CrAS, four enzymes capable of catalyzing the production of α-amyrin from 2,3-oxidosqualene, were cloned from Iris tectorum, Malus domestica, Artemisia annua and Catharanthus roseus, subject to sequence alignment and phylogenetic tree analyses, and transformed into Saccharomyces cerevisiae as plasmids. After 7 days of fermentation, the yield and proportions of α-amyrin, β-amyrin and ergosterol were measured. Finally, AaOSC2 with the best ability to catalyze the generation of α-amyrin was filtered out, providing a key gene element for the later construction of engineered yeast strains with high production of α-amyrin and ursolic acid.