A magnetic hydrogel for the efficient retrieval of kidney stone fragments during ureteroscopy.

Only 60-75% of conventional kidney stone surgeries achieve complete stone-free status. Up to 30% of patients with residual fragments <2 mm in size experience subsequent stone-related complications. Here we demonstrate a stone retrieval technology in which fragments are rendered magnetizable with a magnetic hydrogel so that they can be easily retrieved with a simple magnetic tool. The magnetic hydrogel facilitates robust in vitro capture of stone fragments of clinically relevant sizes and compositions. The hydrogel components exhibit no cytotoxicity in cell culture and only superficial effects on ex vivo human urothelium and in vivo mouse bladders. Furthermore, the hydrogel demonstrates antimicrobial activity against common uropathogens on par with that of common antibiotics. By enabling the efficient retrieval of kidney stone fragments, our method can lead to improved stone-free rates and patient outcomes.

Multifunctional Hybrid Nanocomposite Hydrogel Releasing Different Biomolecular Species Triggered with Different Biochemical Signals Processed by Orthogonal Biocatalytic Reactions.

A micro/nanoshaped system composed of alginate microspheres (microgels) decorated with silica oxide nanoparticles functionalized with nitroavidin was used for on-demand biomolecule release stimulated by different input signals. Enzymes preloaded in the microgels processed the applied signals producing either basic pH locally near the microspheres or generating H2O2 inside the hydrogel, or both simultaneously. The pH increase resulted in cleavage of the affinity bonds between nitroavidin and biotin, then releasing the latter. The H2O2 produced resulted in oxidative cleavage of cross-linking bonds in the alginate matrix, then opening pores and releasing a loaded model protein (bovine serum albumin).

UV-Cured Green Polymers for Biosensorics: Correlation of Operational Parameters of Highly Sensitive Biosensors with Nano-Volumes and Adsorption Properties.

The investigated polymeric matrixes consisted of epoxidized linseed oil (ELO), acrylated epoxidized soybean oil (AESO), trimethylolpropane triglycidyl ether (RD1), vanillin dimethacrylate (VDM), triarylsulfonium hexafluorophosphate salts (PI), and 2,2-dimethoxy-2-phenylacetophenone (DMPA). Linseed oil-based (ELO/PI, ELO/10RD1/PI) and soybean oil-based (AESO/VDM, AESO/VDM/DMPA) polymers were obtained by cationic and radical photopolymerization reactions, respectively. In order to improve the cross-linking density of the resulting polymers, 10 mol.% of RD1 was used as a reactive diluent in the cationic photopolymerization of ELO. In parallel, VDM was used as a plasticizer in AESO radical photopolymerization reactions. Positron annihilation lifetime spectroscopy (PALS) was used to characterize vegetable oil-based UV-cured polymers regarding their structural stability in a wide range of temperatures (120-320 K) and humidity. The polymers were used as laccase immobilization matrixes for the construction of amperometric biosensors. A direct dependence of the main operational parameters of the biosensors and microscopical characteristics of polymer matrixes (mostly on the size of free volumes and water content) was established. The biosensors are intended for the detection of trace water pollution with xenobiotics, carcinogenic substances with a very negative impact on human health. These findings will allow better predictions for novel polymers as immobilization matrixes for biosensing or biotechnology applications.

Nanozyme-Triggered DNA Release from Alginate Films.

Alginate hydrogel thin films of different compositions were electrochemically produced at an electrode surface, and their interfacial reactions were studied for biomolecule release. Nanozyme catalytic species represented by Au nanoparticles were used to trigger biomolecule release from an Fe3+-cross-linked alginate hydrogel film upon receiving a glucose signal. The oxidase-mimicking reaction catalyzed by Au nanoparticles resulted in the production of H2O2, which yielded free radicals through a Fenton-type reaction in the presence of iron cations. The generated free radicals resulted in degradation/dissolution of the alginate matrix and stimulated the release of entrapped DNA molecules. The systematic study addressed the issues of the uncontrolled leakage of the DNA molecules from alginate hydrogel and demonstrated the signal-triggered DNA release in systems with various configurations, ranging from a simple addition of H2O2 to the bulk solution to the in situ production of H2O2 by the nanozyme coentrapped in the alginate film. The present study adds an additional feature to the multioperational functions of nanozymes, representing their use in signal-controlled biomolecule-releasing systems.