Scalable Surface Area Characterization by Electrokinetic Analysis of Complex Anion Adsorption

By means of the in situ electrokinetic assessment of aqueous particles in conjunction with the addition of anionic adsorbates, we develop and examine a new approach to the scalable characterization of the specific accessible surface area of particles in water. For alumina powders of differing morphology in mildly acidic aqueous suspensions, the effective surface charge was modified by carboxylate anion adsorption through the incremental addition of oxalic and citric acids. The observed zeta potential variation as a function of the proportional reagent additive was found to exhibit inverse hyperbolic sine-type behavior predicted to arise from monolayer adsorption following the Grahame–Langmuir model. Through parameter optimization by inverse problem solving, the zeta potential shift with relative adsorbate addition revealed a nearly linear correlation of a defined surface-area-dependent parameter with the conventionally measured surface area values of the powders, demonstrating that the proposed analytical framework is applicable for the in situ surface area characterization of aqueous particulate matter. The investigated methods have advantages over some conventional surface analysis techniques owing to their direct applicability in aqueous environments at ambient temperature and the ability to modify analysis scales by variation of the adsorption cross section

Triple Hit with Drug Carriers: pH- and Temperature-Responsive Theranostics for Multimodal Chemo- and Photothermal Therapy and Diagnostic Applications

Currently there is a strong need for new drug delivery systems, which enable targeted and controlled function in delivering drugs while satisfying highly sensitive imaging modality for early detection of the disease symptoms and damaged sites. To meet these criteria we develop a system that integrates therapeutic and diagnostic capabilities (theranostics). Importantly, therapeutic efficacy of the system is enhanced by exploiting synergies between nanoparticles, drug, and hyperthermia. At the core of our innovation is near-infrared (NIR) responsive gold nanorods (Au) coated with drug reservoirsmesoporous silica shell (mSi)that is capped with thermoresponsive polymer. Such design of theranostics allows the detection of the system using computed tomography (CT), while finely controlled release of the drug is achieved by external trigger, NIR light irradiationON/OFF switch. Doxorubicin (DOX) was loaded into mSi formed on the gold core (Au@mSi-DOX). Pores were then capped with the temperature-sensitive poly­(<i>N</i>-isopropylacrylamide)-based <i>N</i>-butyl imidazolium copolymer (poly­(NIPAAm-<i>co</i>-BVIm)) resulting in a hybrid systemAu@mSi-DOX@P. A 5 min exposure to NIR induces polymer transition, which triggers the drug release (pores opening), increases local temperature above 43 °C (hyperthermia), and upregulates particle uptake (polymer becomes hydrophilic). The DOX release is also triggered by drop in pH enabling localized drug release when particles are taken up by cancer cells. Importantly, the synergies between chemo- and photothermal therapy for DOX-loaded theranostics were confirmed. Furthermore, higher X-ray attenuation value of the theranostics was confirmed via X-ray CT test indicating that the nanoparticles act as contrast agent and can be detected by CT

TCAg1 supplementary information from A reversible fluorescent probe for monitoring Ag(I) ions

Supplementary figure

Additional file 1 of Advanced pathophysiology mimicking lung models for accelerated drug discovery

Additional file1: Table S1. Summary of primary and secondary antibodies used in IF staining for sectioned models