Surface-structured bacterial cellulose loaded with hUSCs accelerate skin wound healing by promoting angiogenesis in rats.

Promotion of wound healing is one of the most important fields in clinical medical research. This study aimed to evaluate the potential use of a new surface-structured bacterial cellulose(S-BC) biomaterial with human urine-derived stem cells (hUSCs) for wound healing. In vitro, EA.hy926 were inoculated on structured/non-structured bacterial cellulose, and the growth of EA.hy926 on bacterial cellulose in medium with/without conditioned medium of the hUSCs were observed to explore the effect of bacterial cellulose's surface structure and hUSCs-CM on vascular endothelial cell growth. In vivo, we covered wound surface with various BC materials and/or injected the hUSCs into the wound site on group BC, group S-BC, group hUSCs, group BC + hUSCs, group S-BC + hUSCs to evaluate the effect of S-BC and hUSCs on wound healing in rat full-thickness skin defect model. In vitro study, surface structure of S-BC could promote the growth and survival of EA.hy926, and the hUSCs-CM could further promote the proliferation of EA.hy926 on S-BC. In vivo study, wound healing rate of the group BC, group S-BC, group hUSCs was significantly accelerated, accompanied by faster re-epithelialization, collagen production and neovascularization than control group. It is note worthy that the effect of S-BC on wound healing was better than BC, the effect of S-BC + hUSCs on wound healing was better than BC + hUSCs. Moreover, the effect of S-BC combined with hUSCs on wound is better than treated with S-BC or hUSCs alone. All the findings suggest that the combination of S-BC and hUSCs could facilitate skin wound healing by promoting angiogenesis. This combination of the role of stem cells and biomaterial surface structures may provide a new way to address clinical wound healing problems.

From a pro-apoptotic peptide to a lytic peptide: One single residue mutation.

Further discovery and design of new anticancer peptides are important for the development of anticancer therapeutics, and study on the detailed acting mechanism and structure-function relationship of peptides is critical for anticancer peptide design and application. In this study, a novel anticancer peptide ZXR-1 (FKIGGFIKKLWRSKLA) derived from a known anticancer peptide mauriporin was developed, and a mutant ZXR-2 (FKIGGFIKKLWRSLLA) with only one residue difference at the 14th position (Lys→Leu) was also engineered. Replacement of the lysine with leucine made ZXR-2 more potent than ZXR-1 in general. Even with only one residue mutation, the two peptides displayed distinct anticancer modes of action. ZXR-1 could translocate into cells, target on the mitochondria and induce cell apoptosis, while ZXR-2 directly targeted on the cell membranes and caused membrane lysis. The variance in their acting mechanisms might be due to the different amphipathicity and positive charge distribution. In addition, the two Ile-Leu pairs (3-10 and 7-14) in ZXR-2 might also play a role in improving its cytotoxicity. Further study on the structure-function relationship of the two peptides may be beneficial for the design of novel anticancer peptides and peptide based therapeutics.

Facile room-temperature solution-phase synthesis of a spherical covalent organic framework for high-resolution chromatographic separation.

A simple and facile room-temperature solution-phase synthesis was developed to fabricate a spherical covalent organic framework with large surface area, good solvent stability and high thermostability for high-resolution chromatographic separation of diverse important industrial analytes including alkanes, cyclohexane and benzene, α-pinene and ß-pinene, and alcohols with high column efficiency and good precision.