PLGA-Coated Drug-Loaded Nanotubes Anodically Grown on Nitinol

This study evaluates the use of nanotubes (NTs) as a matrix for local drug delivery modified by a biodegradable polymeric coating on medical-grade nitinol (NiTi alloy) surfaces. For this purpose, NiTi was anodized within parameters that promote the formation of NTs, ultrasonicated, annealed and impregnated with vancomycin hydrochloride. To improve bioperformance, poly(lactic-co-glycolic acid) (PLGA) was also deposited on the drug-loaded NTs. The samples were characterized in terms of structure, wettability, drug delivery, corrosion and cytocompatibility. Scanning electron microscopy and water contact angle measurements signify the formation of open-top homogeneous NTs of 600– 700 nm in length and ~30 nm in diameter with improved hydrophilicity. The bare antibiotic-impregnated NTs exhibit a burst release of about 49% of the loaded drug in the first 6 h of soaking in a physiological medium, followed by the entire drug diffusing out before 96 h. The PLGA coating effectively controls the burst release of vancomycin to 26% and retains almost 50% of the loaded drug beyond 7 days. The kinetics of the different vancomycin-release stages is also correlated to several well-established models. As a comparative criterion of metallic ions leaching kinetics, the corrosion resistance of nitinol is found to be reduced by the formation of the NTs, while the PLGA coating enhances this electrochemical feature. Due to the alteration of the drug delivery and corrosion protection, the PLGA-coated vancomycin-impregnated sample presents a higher dental pulp stem cell viability in comparison to both the bare drug-loaded and non-loaded NTs. In conclusion, PLGA-coated vancomycin-loaded NT-covered NiTi can be effectively used as a controlled drug-delivery device, while having a drug-release dosage within the therapeutic window and a minimal negative effect on biocompatibility

Probabilistic metric of infrastructure resilience considering time-dependent and time-independent covariates

The lifetime estimation for power semiconductors individually is a mature technology, and many empirical lifetime estimation models have been develo-ped based on abundant test data by several projects, such as LESIT project (Held et al., 1997) and the German project, RAPSDRA (Bayerer et al., 2008). These approaches analytically estimate the lifetime of a device module in terms of the number of cycles to failure Nf considering variable factors such as cyclic junction temperature variations ∆Tj, medium junction temperature, frequency and wire-bond current. These descriptive models are purely statistical analyses and have proven to be unsatisfactory since the aging effects due to the amplitude of junction temperature variations ∆Tj are not well considered (Lai et al., 2015), thus these approaches are not yet suitable in power fluctuation condition

Emerging Antineoplastic Gold Nanomaterials for Cervical Cancer Therapeutics: A Systematic Review

Cervical cancer, a malignant neoplasm arising from cervix cells, remains one of the leading global cause of women cancer-related deaths. The present study was aimed to conduct a comprehensive systematic review to show the anticancer activity of biological mediated gold nanoparticles (AuNPs) against cervical cancer cells. To identify the articles, a systematic search was performed through the electronic databases including Web of Science, PubMed, Scopus, Science Direct, ProQuest, Embase, and Cochrane for the articles published up to 31 August 2019. Thirty-three articles met our eligibility criteria and were entered into the present systematic review. Our finding showed that twenty-eight articles stated the biogenic AuNPs-induced cytotoxicity against cervical cancer cells, whereas five reports said no cytotoxicity. In this study, the proposed molecular mechanisms of biogenic AuNPs-induced cytotoxicity were discussed. In total, the studies suggested the induction of apoptosis and overgeneration of intracellular reactive oxygen species (ROS) through the AuNPs-treated cervical cells. The information of this study may help the researchers for translation laboratory setting studies to clinical researches. Future investigations are required to represent the efficacy of biogenic AuNPs through in vivo models alone or combination with other anticancer drugs. © 2019, Springer Science+Business Media, LLC, part of Springer Nature