With the rapid development of implantable biomaterials, the rising risk of bacterial infections has drawn widespread concern. Due to the high recurrence rate of bacterial infections and the issue of antibiotic resistance, the common treatments of peri-implant infections cannot meet the demand. In this context, stimuli-responsive biomaterials have attracted attention because of their great potential to spontaneously modulate the drug releasing rate. Numerous smart bacteria-responsive drug delivery systems (DDSs) have, therefore, been designed to temporally and spatially release antibacterial agents from the implants in an autonomous manner at the infected sites. In this review, we summarized recent advances in bacteria-responsive DDSs used for combating bacterial infections, mainly according to the different trigger modes, including physical stimuli-responsive, virulence-factor-responsive, host-immune-response responsive and their combinations. It is believed that the smart bacteria-responsive DDSs will become the next generation of mainstream antibacterial therapies.
Neutrophils, as first-line immune cells, typically lose their edge within the diabetic wounds accompanied by methicillin-resistant Staphylococcus aureus (MRSA) infections (the D/M setting), playing the role of "more foe than friend" during the healing process. Specifically, reduced influx of calcium ions (Ca2+) and impaired calcium homeostasis yield the dysfunction of neutrophil sequential behaviors in pathogen killing and wound healing, manifesting as suppressed chemotaxis, decreased intracellular reactive oxygen species (ROS) generation, prolonged apoptosis, and retention of neutrophil extracellular traps (NETs). To address this challenge, this study fabricated potassium (K)-doped manganese dioxide nanoparticles (MnO2 NPs), which activated transmembrane Ca2+ channels by inducing neutrophil depolarization via electron transfer. Subsequently, this contributed to the initial Ca2+ influx and reprogrammed Ca2+-dependent behaviors of impaired neutrophils. Also, the potential antimicrobial capacity of K-MnO2 NPs created a favorable extracellular environment that restored calcium homeostasis, enabling apoptotic neutrophils to be removed timely. Therefore, the wounds treated with K-MnO2 NPs in the D/M setting exhibited potent resistance to MRSA and rapid healing, which could be attributed to the synergistic effects of K-MnO2 NPs in leveraging Ca2+ influx and maintaining calcium homeostasis. In brief, K-MnO2 NPs constitute an effective strategy to resist MRSA and rapid wound healing in the D/M setting.
Background: In recent decades, the global life expectancy has risen notably to approximately 73.5 years worldwide, coinciding with a rapid growth in the older adult population, which presents a significant public health challenge in promoting healthy aging and longevity. Objective: This study aimed to prospectively investigate the link between edentulousness and the likelihood of reaching centenarian status among individuals aged 80 years and older. Methods: Data from the Chinese Longitudinal Healthy Longevity Survey were analyzed. Logistic regression models were used to assess the relationship between edentulousness and the likelihood of becoming a centenarian. Demographic characteristics, lifestyle habits, and disease histories were adjusted as confounding factors. Several sensitivity analyses, including propensity score matching and 2-year lag analyses, were conducted to further assess the association between edentulousness and the likelihood of becoming a centenarian. The correlation between the number of natural teeth as a continuous variable and the likelihood of becoming a centenarian was evaluated as well. Results: The study included 4239 participants aged 80-100 years. After adjusting for all covariates, the likelihood for becoming a centenarian increased in the nonedentulous group compared to the edentulous group (odds ratio [OR] 1.384, 95% CI 1.093‐1.751). The relationship persisted after propensity score matching analysis (OR 1.272, 95% CI 1.037‐1.561). The association remained statistically significant after excluding participants with a follow-up duration of less than 2 years (OR 1.522, 95% CI 1.083‐2.140; P=.02). Furthermore, a significant positive association between the number of natural teeth and the likelihood of becoming a centenarian was found after adjusting for all covariates (OR 1.022, 95% CI 1.002‐1.042; P=.03), which aligned with the main results of the study. Conclusions: The findings revealed that the presence of natural teeth was linked to an increased probability of becoming a centenarian, underscoring the importance of maintaining oral health even in advanced age.