Non-passivated manganese-based carbonaceous nanoparticles selectively target kidney outer medulla, exhibiting renal clearance, high T1-weighted MRI contrast, subtle citotoxicity and low opsonization level.

Nanoparticle passivation by molecular recognition moieties (small molecules, aptamers, antibodies) imputes unique characteristics to nanoparticles (NPs) and unlocks their fascinating selectivity to targeting disease sites. Although non-passivated nanomaterials may archive selective targeting by exploring NP features and their interaction with biofluids proteins, such studies are scarce in the literature. Here, we report spherical manganese-based carbonaceous NPs (MnCQD), which specifically target mice kidneys after intravenous injection, even without direct surface chemical modification. Also, the NPs provide high image contrast in T1 magnetic resonance imaging (MRI) with subtle toxicological effects. The unexpected selectivity of MnCQD to the kidney has been examined based on their determined intrinsic properties and their interaction with two blood proteins: Bovine Serum Albumin (BSA), and Human Transferrin (HTF). More particularly, aspects such as size, composition, superficial charge, spectroscopic features, interaction mechanism, affinities, thermodynamic, and protein structural changes have been investigated. All these results highlight the excellent potential of MnCQD as a low toxic T1-MRI contrast agent and open the prospect of using non-functionalized NPs as a selective agent to target specific organs.

The Effect of Two-Stage Acid Treatment on Surface Behavior and Improvement of Bioactivity of Nitinol Alloy

Surface properties, including morphology, submicron morphology, and surface chemistry, are essential factors that affect the quality and manner of biological responses at the site of tissue contact with the implant, affecting the bone healing process. In this in vitro study, morphology and biocompatibility of nitinol (NiTi) memory alloy surfaces mechanically polished and modified with a chemical solution consisting of three types of acid (HCl-HF-H3PO4) and then chemical operations in solution (HNO3 and HCl) with a Volumetric scale of 1:1 and examined at ambient temperature. 75 samples were used for surface chemical modification, biological evaluations, and surface roughness, and also 9 samples as control. Scanning electron microscopy (SEM), atomic force microscopy (AFM), and nitinol alloy (NiTi) surface roughness measurements were performed to analyze the surfaces. Besides, MG-63 cells were cultured on different nitinol alloy levels to evaluate adhesion and cell growth and proliferation. Data were analyzed using t-test and one-way analysis of variance. The results show that the chemical surface modification operation with two-stage acid solution had a higher roughness compared to the unmodified surfaces and the surface chemical modification operation with the acidic solution with an only solution consisting of (HCl-HF-H3PO4). Cell culture evaluations also showed that the two-stage modified nitinol levels showed significant cell adhesion and significant growth and proliferation compared to the tertiary acid-modified and unmodified levels. The surface chemical modification method for nitinol alloy can change the surface chemistry and change the surface morphology and create sub-micron scale roughness. This can increase the connectivity of the implant tissue and reduce the toxic effect of nickel.

Chemically robust succinimide-group-assisted irreversible bonding of poly(dimethylsiloxane)–thermoplastic microfluidic devices at room temperature

This study investigates surface chemical modification using anhydride silane and amino silane reagents at room temperature (RT) to realize bonding between silicon-based PDMS and non-silicon thermoplastics.

Improvement of Dielectric Breakdown Performance by Surface Modification in Polyethylene/TiO2 Nanocomposites

Dielectric breakdown is a significant property for the insulation system in high voltage power equipment. This paper is dedicated to the improvement of dielectric breakdown by surface-functionalized nanoparticles in low-density polyethylene (LDPE). Prior to the preparation of LDPE/TiO2 nanocomposites, the nanoparticles were surface modified by the silane coupling followed by the chemical reaction process. Results of Fourier transform infrared spectroscopy (FTIR) indicated that some polar groups and chemical bonding were introduced on the surface of TiO2 nanoparticles. A reduction of dielectric permittivity was observed at low nanoparticle loading (<2 wt%) samples, which responded to the restriction of the molecular chain in the interface region. High nanoparticle loadings (2 wt%, 5 wt%, 10 wt%) introduced an obvious relaxation polarization. The trap parameters detected by the thermally stimulated current (TSC) method indicated that the deep traps were introduced by small amounts of nanoparticles (≤2 wt%), while more shallow traps occurred in high loading (5 wt%, 10 wt%) samples. Meanwhile, the increase of breakdown strength at low loading samples were closely related to the deep traps, which was ascribed to the interface region by surface chemical modification.