Super-resolution imaging reveals subtle interplay between nanoscopic organization of membrane ligands and cellular interaction.

The repair and remodeling of injured tissues, known as wound healing, is a multifaceted process. The use of nanotechnology to speed up the healing process of wounds by promoting the right kind of mobility through different mechanisms has shown a lot of promise. Several nanotechnologies with novel properties have emerged in recent years, each of which targets a different issue associated with wound-healing processes. Through their antibacterial, anti-inflammatory, and angiogenic actions, nanomaterials may alter the wound microenvironment from a non-healing to a healing state. Wound dressings including hydrogels, gelatin sponges, films, and bandages may all benefit from the use of nanoparticles (NPs) to keep harmful microbes out. The addition of bioactive substances like antibiotics, NPs, and growth factors to certain dressings may further boost their efficacy. In conclusion, this review sheds light on wound healing that may be aided by the special features of materials based on nanotechnology. Although nanomaterials for wound healing show great promise, further study is needed before this promising area can convert its findings into consumer-friendly solutions.

Selectins are key to mediating interactions involved in cellular adhesion and migration, underlying processes such as immune responses, metastasis, and transplantation. Selectins are composed of a lectin domain, an epidermal growth factor (EGF)-like domain, multiple short consensus repeats (SCRs), a transmembrane domain, and a cytoplasmic tail. It is well-established that the lectin and EGF domains are required to mediate interactions with ligands; however, the contributions of the other domains in mediating these interactions remain obscure. Using various E-selectin constructs produced in a newly developed silkworm-based expression system and several assays performed under both static and physiological flow conditions, including flow cytometry, glycan array analysis, surface plasmon resonance, and cell-rolling assays, we show here that a reduction in the number of SCR domains is correlated with a decline in functional E-selectin binding to hematopoietic cell E- and/or L-selectin ligand (HCELL) and P-selectin glycoprotein ligand-1 (PSGL-1). Moreover, the binding was significantly improved through E-selectin dimerization and by a substitution (A28H) that mimics an extended conformation of the lectin and EGF domains. Analyses of the association and dissociation rates indicated that the SCR domains, conformational extension, and dimerization collectively contribute to the association rate of E-selectin–ligand binding, whereas just the lectin and EGF domains contribute to the dissociation rate. These findings provide the first evidence of the critical role of the association rate in functional E-selectin–ligand interactions, and they highlight that the SCR domains have an important role that goes beyond the structural extension of the lectin and EGF domains.

Hematopoietic stem/progenitor cell (HSPC) and leukemic cell homing is an important biological phenomenon that occurs through key interactions between adhesion molecules. Tethering and rolling of the cells on endothelium, the crucial initial step of the adhesion cascade, is mediated by interactions between selectins expressed on endothelium to their ligands expressed on HSPCs/leukemic cells in flow. Although multiple factors that affect the rolling behavior of the cells have been identified, molecular mechanisms that enable the essential slow and stable cell rolling remain elusive. Here, using a microfluidics-based single-molecule live cell fluorescence imaging, we reveal that unique spatiotemporal dynamics of selectin ligands on the membrane tethers and slings, which are distinct from that on the cell body, play an essential role in the rolling of the cell. Our results suggest that the spatial confinement of the selectin ligands to the tethers and slings together with the rapid scanning of a large area by the selectin ligands, increases the efficiency of selectin-ligand interactions during cell rolling, resulting in slow and stable rolling of the cell on the selectins. Our findings provide novel insights and contribute significantly to the molecular-level understanding of the initial and essential step of the homing process.

Mycobacterium vaccae is a rapidly growing, nontuberculous Mycobacterium species that is generally not considered a human pathogen and is of major pharmaceutical interest as an immunotherapeutic agent. We report here the annotated genome sequence of the M. vaccae type strain, ATCC 25954.

Background/Objectives: Proton pump inhibitors (PPIs) are amongst the most commonly prescribed classes of medication. However, inappropriate PPI use can lead to several adverse drug reactions (ADRs). Limited data exist on factors contributing to the risk of ADRs associated with PPI prescribing patterns in the Eastern Region of Saudi Arabia. This retrospective, cross-sectional study aimed to assess the prevalence and the pattern of PPI use and to identify factors contributing to the risk of ADRs. Methods: Data were collected from electronic medical records of patients at Al-Qateef Central Hospital from January 2020 to December 2021. The inclusion criteria included patients aged ≥40 years attending an outpatient medical care clinic. PPI prescribing patterns were categorized based on their dosage intensity into low-dose, medium-dose (MD), and high-dose (HD) categories. Binary and multinominal logistic regression models were used to determine the relationship between PPI prescribing patterns and use, categorized by MD or HD, and patient characteristics, adjusted for significant covariates. Results are presented as adjusted odds ratio (OR) with corresponding 95% confidence intervals (95% CI). Results: The study included 41,084 patients. The prevalence of PPI prescribing was 31%. PPI users were more frequently found to be females than males (52% vs. 50%, p = 0.013); they were also likely to be prescribed more medications (7 vs. 6, p < 0.001), but less likely to have gastritis-related diseases (34% vs. 32%, p < 0.001) compared to non-users. PPI HD users were more likely male (56% vs. 43%, p < 0.001), older (53 vs. 52 years, p < 0.001), and prescribed more medications (11.8 vs. 2.8, p < 0.001) compared to MD users. PPI usage was associated with concurrent use of antiplatelet drugs (OR = 1.08, 95% CI 1.01–1.15). An increasing number of prescribed medications was associated with HD usage (OR = 1.13, 95% CI 1.12–1.14), but negatively associated with MD usage (OR = 0.7 95% CI 0.69–0.71). Female gender was negatively associated with HD usage (OR = 0.85, 95% CI 0.79–0.91). Conclusions: Our findings indicate that 31% of the included cohort were prescribed PPI. Inappropriate PPI prescribing related to the drug’s omission is a concern as PPI non-users presented with valid indications such as gastritis. Male gender and increasing NPM were the common factors contributing to increased risk of PPI ADR. This study points to the importance of re-evaluating PPI use to ensure effective therapy with minimum risks of ADR.