Preparation of MSNs@Keratin as pH/GSH dual responsive drug delivery system.

Designing a drug delivery system that is responsive in a tumor microenvironment is important to potentiate the efficacy and reduce the side effects of antitumor drugs. In this study, the surface of mesoporous silica nanoparticles (MSNs) were aminated with 3-aminopropyl triethoxysilane (APTES) and then coupled with keratin, as a gatekeeper, to afford MSNs-NH2@Keratin. The average sizes and morphologies of MSNs and MSNs-NH2@Keratin were characterized with dynamic light scattering and transmission electron microscopy, respectively. The loading content and encapsulation efficiency of doxorubicin (DOX) were calculated to be 17.1 ± 1.7% and 71.3 ± 2.1%. Drug-loaded MSNs-NH2@Keratin exhibited pH and glutathione (GSH) dual responsiveness under tumor microenvironment. The nanoparticles could be uptaken by tumor cells to effectively inhibit tumor cell growth. Moreover, the sizes of nanoparticle were stable in the serum. Collectively, our findings demonstrated the potential of DOX-loaded MSNs-NH2@Keratin in the treatment of cancer.

Association between life-course cigarette smoking and metabolic syndrome: a discovery-replication strategy.

BACKGROUND: The relation between cigarette smoking and metabolic syndrome (MetS) remains unclear, and previous studies focusing on MetS are limited in sample size. We investigated the association between life-course smoking and MetS with independent discovery and replication samples. METHODS: Preliminary analysis utilized data from an annual cross-sectional survey of 15,222 participants aged ≥ 60 years in Tianjin, China. Suggestive associations were followed-up in 8565 adults from the China Health and Nutrition Survey. MetS was identified according to the criteria of the Chinese Diabetes Society in 2013. Life-course smoking was assessed by a comprehensive smoking index (CSI), based on information on smoking intensity, duration, and time since cessation across life-course, collected through standard questionnaires. Participants were divided into four groups: non-smokers; and the tertiles of CSI in ever smokers. Multivariable logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs) for the association between life-course smoking and MetS. RESULTS: In the discovery sample, ORs of MetS were 2.01 (95%CI: 1.64-2.47) and 1.76 (95%CI: 1.44-2.16) for smokers in the highest and second tertile of CSI compared with never smokers. Potential interaction was shown for age, with increased ORs for MetS associated with smoking limited to individuals who aged < 70 years (Pinteraction = 0.015). We were able to replicate the association between cigarette smoking and MetS in an independent adult sample (second tertile vs. never: OR = 1.30, 95%CI: 1.04-1.63). The interaction of smoking with age was also replicated. CONCLUSIONS: Life-course cigarette smoking is associated with an increased odds of MetS, especially among individuals who aged < 70 years.