Imidazolium-Based Main-Chain Copolymers With Alternating Sequences for Broad-Spectrum Bactericidal Activity and Eradication of Bacterial Biofilms.

In response to the escalating challenge of bacterial drug resistance, the imperative to counteract planktonic cell proliferation and eliminate entrenched biofilms underscores the necessity for cationic polymeric antibacterials. However, limited efficacy and cytotoxicity challenge their practical use. Here, novel imidazolium-based main-chain copolymers with imidazolium (PIm+) as the cationic component are introduced. By adjusting precursor molecules, hydrophobicity and cationic density of each unit are fine-tuned, resulting in broad-spectrum bactericidal activity against clinically relevant pathogens. PIm+1 stands out for its potent antibacterial performance, with a minimum inhibitory concentration of 32 µg mL-1 against Methicillin-resistant Staphylococcus aureus (MRSA), and substantial biofilm reduction in Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) biofilms. The bactericidal mechanism involves disrupting the outer and cytoplasmic membranes, depolarizing the cytoplasmic membrane, and triggering intracellular reactive oxygen species (ROS) generation. Collectively, this study postulates the potential of imidazolium-based main-chain copolymers, systematically tailored in their sequences, to serve as a promising candidate in combatting drug-resistant bacterial infections.

Association between Social Participation and Remaining Teeth and Urban-Rural Difference among Older Adults in China.

Oral health is an important part of older adults' general health. The study examined the association between social participation (formal and informal) and remaining teeth and the urban-rural difference based on a national survey of older adults in China. The data of older adults were extracted from the Chinese Longitudinal Healthy Longevity Survey (CLHLS) and analyzed. A total of 11,948 respondents were ultimately involved, including 6836 urban respondents and 5112 rural respondents. Informal social participation and formal social participation were used to assess social participation. The number of remaining natural teeth was measured. Social participation was significantly associated with remaining teeth among older adults, after adjusting for confounders, a one-level increase in the informal social participation was associated with a decrease in natural teeth by 0.152 (95% CI = -0.274; -0.030) and a one-level increase in the formal social participation was associated with a decrease in natural teeth by 0.370 (95% CI = -0.585; -0.156). In addition, the association between social participation (formal and informal) and remaining teeth was observed among urban older adults, but not rural older adults. A high level of social participation may effectively decrease the risk of oral-health problems for the Chinese older adults. The findings suggest recommendations for an older adults-targeted policy and the practice of oral-health promotion. However, the urban-rural difference should be taken into full consideration in social-participation-driven oral-health promotion interventions.