Use of Core-Cross-Linked Polymeric Micelles Induced by the Selective Detection of Cu(II) Ions for the Sustained Release of a Model Drug

Fabricating Polymeric Micelles with Enrichment and Cavity Effect for In Situ Enzyme Imobilization from Natural Biosystems

Metal-organic frameworks and hydrogen-organic frameworks (MOFs and HOFs) are attractive hosts for enzyme immobilization, but they are limited to immobilizing the purified enzymes, making industrial upscaling unattractive. Herein, aptamer-modified dual thermoresponsive polymeric micelles with switchable self-assembly and core-shell structure are constructed, which enable selective immobilization of trypsin directly from complex biological systems through a cascade operation of separation and immobilization. Their steric self-assembly provides a large amount of adsorption sites on the soluble micellar shell, resulting in high adsorption capacity and excellent selectivity. Meanwhile, their aptamer affinity ligand and cavity maintain the native conformations of trypsin and offer protective effects even in harsh conditions. The maximum adsorption capacity of the polymeric micelles for trypsin was determined to be 197 mg/g at 60 min, superior to those of MOFs and HOFs. 67.2 and 86.6% of its original activity was retained for trypsin immobilized in the cavity under strong alkaline and acidic conditions, respectively.

Phenylthiosemicarbazide-functionalized UiO-66-NH2 as highly efficient adsorbent for the selective removal of lead from aqueous solutions

A novel metal-organic framework (UiO-66-PTC) for efficient removal of Pb²⁺ ions from wastewater has been prepared by using 4-phenyl-3-thiosemicarbazide as the modifier. Various characterizations showed that UiO-66-PTC was successfully synthesized. The absorption results showed that the maximum adsorption capacity of Pb(II) is 200.17 mg/g at 303 K and optimal pH 5. The adsorption kinetic follows the pseudo-second-order model and the adsorption isotherms fit the Langmuir model. This shows that Pb(II) is a single-layer adsorption on the surface of the adsorbent and the rate-controlling step is chemical adsorption. The thermodynamic results show that the adsorption process can proceed spontaneously, belong to the exothermic reaction. The adsorbent can selectively uptake lead ions from wastewater containing multiple interfering ions. After four adsorption and desorption cycles, the adsorption efficiency is still high. The adsorption mechanism of Pb(II) on the adsorbent is mainly through the chelation of Pb(II) with N and S atoms. These results indicate that UiO-66-PTC is an effective material for efficiently and selectivity removal of Pb(II) from solution, which is of practical significance.

Supramolecular Drug-Drug Complex Vesicles Enable Sequential Drug Release for Enhanced Combination Therapy

Drug-drug self-delivery systems serving as both carriers and cargos have been explored as advanced combination chemotherapy strategies to overcome the limitations of the traditional single-drug chemotherapy. However, most known drug-drug self-delivery systems may cause a rapid increase in drug concentration when the single covalent bond is broken, thus leading to high toxicity to organs and low therapeutic efficiency against tumors. To address the above problem, in this study, a novel supramolecular drug-drug complex (SDDC) simultaneously containing both covalent and noncovalent bonds was proposed to realize the sequential release of two drugs in tumor cells for enhanced combination therapy. The SDDC could self-assemble into uniform bilayer supramolecular vesicles (SVs) with a remarkable drug loading capacity and stable drug transport. Notably, the SVs with controlled sequential release ability in tumor cells exhibited a superior synergistic effect and significantly improved therapeutic efficiency with reduced toxicity in in vivo antitumor activity and histological analyses in comparison to either individual free drugs or a mixture of two free drugs. Therefore, by combining the advantages of noncovalent interactions with the dynamic nature and stable covalent bonds, this study opens a new way for cancer therapy.