Surface Coating of ZIF-8 Nanoparticles with Polyacrylic Acid: A Facile Approach to Enhance Chemical Stability for Biomedical Applications.

Nanoparticles of zeolitic imidazole framework-8 (ZIF-8 NPs), which are the subclass of metal-organic frameworks consisting of Zn ion and 2-methylimidazole, have been identified as promising drug carriers since their large microporous structure is suited for encapsulating hydrophobic drug molecules. However, one of the limitations of ZIF-8 NPs is their low stability in physiological solutions, especially in the presence of water and phosphate anions. These molecules can interact with the coordinatively unsaturated Zn sites at the external surface to induce the degradation of ZIF-8 NPs.

Angpt1 binding to Tie1 regulates the signaling required for lymphatic vessel development in zebrafish.

Development of the vascular system is regulated by multiple signaling pathways mediated by receptor tyrosine kinases. Among them, angiopoietin (Ang)/Tie signaling regulates lymphatic and blood vessel development in mammals. Of the two Tie receptors, Tie2 is well known as a key mediator of Ang/Tie signaling, but, unexpectedly, recent studies have revealed that the Tie2 locus has been lost in many vertebrate species, whereas the Tie1 gene is more commonly present.

Controlled Dissociation of Polymeric Micelles in Response to Oxidative Stress.

Nanoparticle-based drug carriers that can respond to oxidative stress in tumor tissue have attracted attention for site-specific drug release. Taking advantage of the characteristic microenvironment in tumors, one of the attractive directions in drug delivery research is to design drug carriers that release drugs upon oxidation. A strategy to incorporate oxidation-sensitive thioether motifs such as thiomorpholine acrylamide (TMAM) to drug carriers has been often used to achieve oxidation-induced dissociation, thereby targeted drug release.

Manganese Porphyrin-Containing Polymeric Micelles: A Novel Approach for Intracellular Catalytic Formation of Per/Polysulfide Species from a Hydrogen Sulfide Donor.

Per/polysulfide species that are generated from endogenously produced hydrogen sulfide have critical regulatory roles in a wide range of cellular processes. However, the lack of delivery systems that enable controlled and sustained release of these unstable species in biological systems hinders the advancement of sulfide biology research, as well as the translation of knowledge to therapeutic applications. Here, a novel approach is developed to generate per/polysulfide species in cells by combining an H S donor and manganese porphyrin-containing polymeric micelles (MnPMCs) that catalyze oxidization of H S to per/polysulfide species.