Rapid and Efficient Collection of Platinum from Karstedt’s Catalyst Solution via Ligands-Exchange-Induced Assembly

Reported herein is a novel strategy for the rapid and efficient collection of platinum from Karstedt’s catalyst solution. By taking advantage of a ligand-exchange reaction between alkynols and the 1,3-divinyltetramethyldisiloxane ligand (M^ViM^Vi) that coordinated with platinum (Pt(0)), the Karstedt’s catalyst particles with a size of approximately 2.5 ± 0.7 nm could be reconstructed and assembled into larger particles with a size of 150 ± 35 nm due to the hydrogen bonding between the hydroxyl groups of the alkynol. In addition, because the silicone-soluble M^ViM^Vi ligand of the Karstedt’s catalyst was replaced by water-soluble alkynol ligands, the resultant large particles were readily dispersed in water, resulting in rapid, efficient, and complete collection of platinum from the Karstedt’s catalyst solutions with platinum concentrations in the range from ∼20 000 to 0.05 ppm. Our current strategy not only was used for the rapid and efficient collection of platinum from the Karstedt’s catalyst solutions, but it also enabled the precise evaluation of the platinum content in the Karstedt’s catalysts, even if this platinum content was extremely low (i.e., 0.05 ppm). Moreover, these platinum specimens that were efficiently collected from the Karstedt’s catalyst solutions could be directly used for the evaluation of platinum without the need for pretreatment processes, such as calcination and digestion with hydrofluoric acid, that were traditionally used prior to testing via inductively coupled plasma mass spectrometry in conventional methods

Simultaneous Diagnosis and Gene Therapy of Immuno-Rejection in Rat Allogeneic Heart Transplantation Model Using a T‑Cell-Targeted Theranostic Nanosystem

As the final life-saving treatment option for patients with terminal organ failure, organ transplantation is far from an ideal solution. The concomitant allograft rejection, which is hardly detectable especially in the early acute rejection (AR) period characterized by an intense cellular and humoral attack on donor tissue, greatly affects the graft survival and results in rapid graft loss. Based on a magnetic resonance imaging (MRI)-visible and T-cell-targeted multifunctional polymeric nanocarrier developed in our lab, effective co-delivery of pDNA and superparamagnetic iron oxide nanoparticles into primary T cells expressing CD3 molecular biomarker was confirmed <i>in vitro</i>. In the heart transplanted rat model, this multifunctional nanocarrier showed not only a high efficiency in detecting post-transplantation acute rejection but also a great ability to mediate gene transfection in T cells. Upon intravenous injection of this MRI-visible polyplex of nanocarrier and pDNA, T-cell gathering was detected at the endocardium of the transplanted heart as linear strongly hypointense areas on the MRI <i>T</i>₂*-weighted images on the third day after cardiac transplantation. Systematic histological and molecular biology studies demonstrated that the immune response in heart transplanted rats was significantly suppressed upon gene therapy using the polyplex bearing the DGKα gene. More excitingly, the therapeutic efficacy was readily monitored by noninvasive MRI during the treatment process. Our results revealed the great potential of the multifunctional nanocarrier as a highly effective imaging tool for real-time and noninvasive monitoring and a powerful nanomedicine platform for gene therapy of AR with high efficiency

Robust Superamphiphobic Coatings Based on Silica Particles Bearing Bifunctional Random Copolymers

Reported herein is the growth of bifunctional random copolymer chains from silica particles through a “grafting from” approach and the use of these copolymer-bearing particles to fabricate superamphiphobic coatings. The silica particles had a diameter of 90 ± 7 nm and were prepared through a modified Stöber process before atom transfer radical polymerization (ATRP) initiators were introduced onto their surfaces. Bifunctional copolymer chains bearing low-surface-free-energy fluorinated units and sol–gel-forming units were then grafted from these silica particles by surface-initiated ATRP. Perfluorooctyl ethyl acrylate (FOEA) and 3-(triisopropyloxy)­silylpropyl methacrylate (IPSMA) were respectively used as fluorinated and sol–gel-forming monomers in this reaction. Hydrolyzing the IPSMA units in the presence of an acid catalyst yielded silica particles that were adorned with silanol-bearing copolymer chains. Coatings were prepared by spraying these hydrolyzed silica particles onto glass and cotton substrates. A series of four different copolymer-functionalized silica particles samples bearing copolymers with similar FOEA molar fractions (<i>f</i>_F) of ∼80% but with different copolymer grafting mass ratios (<i>g</i>_m) that ranged between 12.3 wt % and 58.8 wt %, relative to silica, were prepared by varying the polymerization protocols. These copolymer-bearing silica particles with a <i>g</i>_m exceeding 34.1 wt % were used to coat glass and cotton substrates, yielding superamphiphobic surfaces. More importantly, these particulate-based coatings were robust and resistant to solvent extraction and NaOH etching thanks to the self-cross-linking of the copolymer chains and their covalent attachment to the substrates

Superparamagnetic-Oil-Filled Nanocapsules of a Ternary Graft Copolymer

Stearic and oleic acid-coated Fe₃O₄ nanoparticles were dispersed in decahydronaphthalene (DN). This oil phase was dispersed in water using ternary graft copolymer poly­(glycidyl methacrylate)-<i>graft</i>-[polystyrene-<i>ran</i>-(methoxy polyethylene glycol)-<i>ran</i>-poly­(2-cinnamoyloxyethyl methacrylate)] or PGMA-<i>g</i>-(PS-<i>r</i>-MPEG-<i>r</i>-PCEMA) to yield capsules. The walls of these capsules were composed of PCEMA chains that were soluble in neither water nor DN, and the DN-soluble PS chains stretched into the droplet phase and the water-soluble MPEG chains extended into the aqueous phase. Structurally stable capsules were prepared by photolyzing the capsules with UV light to cross-link the PCEMA layer. Both the magnetite particles and the magnetite-containing capsules were superparamagnetic. The sizes of the capsules increased as they were loaded with more magnetite nanoparticles, reaching a maximal loading of ∼0.5 mg of ligated magnetite nanoparticles per mg of copolymer. But the radii of the capsules were always <100 nm. Thus, a novel nanomaterialsuperparamagnetic-oil-filled polymer nanocapsuleswas prepared. The more heavily loaded capsules were readily captured by a magnet and could be redispersed via shaking. Although the cross-linked capsules survived this capturing and redispersing treatment many times, the un-cross-linked capsules ruptured after four cycles. These results suggest the potential to tailor-make capsules with tunable wall stability for magnetically controlled release applications