Infected Diabetic Wound Regeneration Using Peptide-Modified Chiral Dressing to Target Revascularization.

Revascularization plays a critical role in the healing of diabetic wounds. Accumulation of advanced glycation end products (AGEs) and refractory multidrug resistant bacterial infection are the two major barriers to revascularization, directly leading to impaired healing of diabetic wounds. Here, an artfully designed chiral gel dressing is fabricated (named as HA-LM2-RMR), which consists of l-phenylalanine and cationic hexapeptide coassembled helical nanofibers cross-linked with hyaluronic acid via hydrogen bonding. This chiral gel possesses abundant chiral and cationic sites, not only effectively reducing AGEs via stereoselective interaction but also specifically killing multidrug resistant bacteria rather than host cells since cationic hexapeptides selectively interact with negatively charged microbial membrane. Surprisingly, the HA-LM2-RMR fibers present an attractive ability to activate sprouted angiogenesis of Human Umbilical Vein Endothelial Cells by upregulating VEGF and OPA1 expression. In comparison with clinical Prontosan Wound Gel, the HA-LM2-RMR gel presents superior healing efficiency in the infected diabetic wound with respect to angiogenesis and re-epithelialization, shortening the healing period from 21 days to 14 days. These findings for chiral wound dressing provide insights for the design and construction of diabetic wound dressings that target revascularization, which holds great potential to be utilized in tissue regenerative medicine.

Kinetic Co-assembly Pathway Induced Chirality Inversion Along with Morphology Transition.

Kinetic co-assembly pathway induced chirality inversion along with morphology transition is of importance to understand biological processes, but still remains a challenge to realize in artificial systems. Herein, helical nanofibers consisting of phenylalanine-based enantiomers (L/DPF) successfully transform into kinetically trapped architectures with opposite helicity through a kinetic co-assembly pathway. By contrast, the co-assemblies obtained by a thermodynamic pathway exhibit non-helical structures. The formation sequence of non-covalent interactions plays a crucial role in structural chirality of co-assemblies. For the kinetic pathway, the hydrogen bonding between D/LPF and naphthylamide derivatives forms before π-π stacking to facilitate the formation of helical structures with inverse handedness. This study may provide an approach to explore chirality inversion accompanied by morphology transition by manipulating the kinetic co-assembly pathway.

Use of Electrospun Phenylalanine/Poly-ε-Caprolactone Chiral Hybrid Scaffolds to Promote Endothelial Remodeling.

The fabrication of tissue-engineered vascular grafts to replace damaged vessels is a promising therapy for cardiovascular diseases. Endothelial remodeling in the lumen of TEVGs is critical for successful revascularization. However, the construction of well-functioning TEVGs remains a fundamental challenge. Herein, chiral hybrid scaffolds were prepared by electrospinning using D/L-phenylalanine based gelators [D(L)PHEG] and poly-ε-caprolactone (PCL). The chirality of scaffolds significantly affected the endothelial remodeling progress of TEVGs. Compared with L-phenylalanine based gelators/poly-ε-caprolactone (L/PCL) and PCL, D-phenylalanine based gelators/poly-ε-caprolactone (D/PCL) scaffolds enhanced cell adhesion, and proliferation and upregulated the expression of fibronectin-1, and vinculin. These results suggests that chiral hybrid scaffolds can promote endothelial remodeling of TEVGs by upregulating adhesion-associated protein levels. This study offers an innovative strategy for endothelial remodeling of TEVGs by fabricating chiral hybrid scaffolds, and provides new insight for the treatment of cardiovascular diseases.

Three-Dimensional Chiral Supramolecular Microenvironment Strategy for Enhanced Biocatalysis.

How the three-dimensional (3D) chiral environment affects the biocatalysis remains an important issue, thereby inspiring the development of a microenvironment that highly mimics the natural features of enzyme to guarantee enhanced biocatalysis. In this study, two gelators bearing d/l-phenylalanine as chiral centers are designed to construct the 3D chiral catalytic microenvironment for enhancing the biocatalysis of lipase. Such a microenvironment is programmed through chiral transmission of chirality from molecular chirality to achiral polymers. It shows that the chirality of the microenvironment evidently influences the catalytic efficiency of immobilized lipase inside the system, and the 3D microenvironment constructed by right-handed helical nanostructures can enhance the catalytic activity of lipase inside as high as 10-fold for catalyzing 4-nitrophenyl palmitate (NPP) to 4-nitrophenol (NP) and 1.4-fold for catalyzing lipids to triglycerides (TGs) in 3T3-L1 cells than that of the achiral microenvironment. Moreover, the 3D chiral microenvironment has the merits of good catalytic efficiency, high storage stability, and efficient recyclability. This strategy of designing a 3D chiral microenvironment suitable for biocatalysis will overcome the present limitations of enzymatic immobilization in traditional materials and enhance the understanding of biocatalysis.

Smartphone addiction may be associated with adolescent hypertension: a cross-sectional study among junior school students in China.

BACKGROUND: Hypertension in children and adolescents is on the rise worldwide, especially in China. The prevalence of hypertension is related to many factors, such as obesity. In the era of smart phones, it is important to study the negative health effects of mobile phones on blood pressure. The purpose of this study was to investigate the prevalence of hypertension and its association with smartphone addiction among junior school students in China. METHODS: A school-based cross-sectional study was conducted, including total 2639 junior school students (1218 boys and 1421 girls), aged 12-15 years old (13.18 ± 0.93 years), enrolled in the study by random cluster sampling. Height, weight, systolic blood pressure (SBP) and diastolic blood pressure (DBP) were measured following standard protocols, and the body mass index (BMI) was calculated. Overweight/obesity and hypertension were defined according to sex- and age-specific Chinese children reference data. The Smartphone Addiction Scale short version (SAS-SV) and the Pittsburgh Sleep Quality Index (PSQI) were used to assess smartphone addiction and sleep quality among the students, respectively. Multivariate logistic regression models were used to seek associations between smartphone addiction and hypertension. RESULTS: The prevalence of hypertension and smartphone addiction among participants were 16.2% (13.1% for females and 18.9% for males) and 22.8% (22.3% for females and 23.2% for males), respectively. Obesity (OR = 4.028, 95% CI: 2.829-5.735), poor sleep quality (OR = 4.243, 95% CI: 2.429-7.411), smartphone addiction (OR = 2.205, 95% CI: 1.273-3.820) were significantly and independently associated with hypertension. CONCLUSIONS: Among the junior school students surveyed in China, the prevalence of hypertension was high, which was related to obesity, poor sleep quality and smartphone addiction. These results suggested that smartphone addiction may be a new risk factor for high blood pressure in adolescents.