Incorporation of Nitroprusside on Silica Nanoparticles-A Strategy for Safer Use of This NO Donor in Therapy.

Silica-based nanoparticles have been developed as powerful platforms for drug delivery and might also prevent undesired side effects of drugs. Here, a fast method to synthesize positively charged mesoporous silica nanoparticles (ζ = 20 ± 0.5 mV, surface area = 678 m2 g-1, and 2.3 nm of porous size) was reported. This nanomaterial was employed to anchor sodium nitroprusside (SNP), a vasodilator drug with undesired cyanide release. A remarkable incorporation of 323.9 ± 7.55 µmol of SNP per gram of nanoparticle was achieved, and a series of studies of NO release were conducted, showing efficient release of NO along with major cyanide retention (ca. 64% bound to nanoparticle). Biological assays with mammalian cells showed only a slight drop in cell viability (13%) at the highest concentration (1000 µM), while SNP exhibited an LC50 of 228 µM. Moreover, pharmacological studies demonstrated similar efficacy for vasodilation and sGC-PKG-VASP pathway activation when compared to SNP alone. Altogether, this new SNP silica nanoparticle has great potential as an alternative for wider and safer use of SNP in medicine with lower cyanide toxicity.

Tablet-Based Hearing Screening Test.

INTRODUCTION: Hearing loss (HL) affects people worldwide, many of whom are children. Especially in developing countries, epidemiological data on the prevalence of HL are insufficient to implement effective health promotion programs. In this preliminary study with young adults, we describe and validate a tablet-based hearing screening test developed for interactive remote hearing screening and compare the performance of an audiometry screening tablet application with conventional audiometry. In addition, the sensitivity, specificity, and predictive values of the tablet-based method and the concordance between the two methods were analyzed. METHODS: Thirty volunteers participated in a double-blind study assessing two auditory threshold screening methods: tablet-based hearing screening and sweep audiometry. For both methods, a correct response to a minimum of two tones out of three emitted at 20 dBHL for the frequencies of 1, 2, and 4 kHz and 30 dBHL for 0.5 kHz in both ears, was considered a negative screening result (normal hearing), whereas hearing impairment was considered a positive screening result. RESULTS: According to both methods, 26 participants had normal hearing and four had HL. The Kappa coefficient indicated perfect concordance between methods. The tablet-based hearing screening method had a sensitivity of 100% (confidence interval [CI]: 30.5-100.0), a specificity of 100% (CI: 87.1-100.0), a positive predictive value of 100% (CI: 30.5-100.0), and a negative predictive value of 100% (CI: 87.1-100.0). CONCLUSIONS: The tablet-based hearing screening test was shown to be a reliable and an accurate method for hearing screening that can be used effectively in places with Internet access and where local audiologists are not available.