Amino Functionality Enables Aqueous Synthesis of Carboxylic Acid-Based MOFs at Room Temperature by Biomimetic Crystallization.

Enzyme immobilization within metal-organic frameworks (MOFs) is a promising solution to avoid denaturation and thereby utilize the desirable properties of enzymes outside of their native environments. The biomimetic mineralization strategy employs biomacromolecules as nucleation agents to promote the crystallization of MOFs in water at room temperature, thus overcoming pore size limitations presented by traditional postassembly encapsulation. Most biomimetic crystallization studies reported to date have employed zeolitic imidazole frameworks (ZIFs). Herein, we expand the library of MOFs suitable for biomimetic mineralization to include zinc(II) MOFs incorporating functionalized terephthalic acid linkers and study the catalytic performance of the enzyme@MOFs. Amine functionalization of terephthalic acids is shown to accelerate the formation of crystalline MOFs enabling new enzyme@MOFs to be synthesized. The structure and morphology of the enzyme@MOFs were characterized by PXRD, FTIR, and SEM-EDX, and the catalytic potential was evaluated. Increasing the linker length while retaining the amino moiety gave rise to a family of linkers; however, MOFs generated with the 2,2'-aminoterephthalic acid linker displayed the best catalytic performance. Our data also illustrate that the pH of the reaction mixture affects the crystal structure of the MOF and that this structural transformation impacts the catalytic performance of the enzyme@MOF.

Drug encapsulating polysaccharide-loaded metal nanoparticles: A perspective drug delivery system.

The anticancer and antimicrobial drugs customarily suffer a functional inefficacy due to a limited delivery to the target site, active cellular efflux, in addition to the inadequacy of carrier system. Metal nanoparticles possess unique physicochemical properties as drug delivery vehicles, for delivering the drugs susceptible to cellular efflux pumps. However, a direct physiological exposure of nanoparticle surface after releasing the carrier drug poses serious concerns. The polysaccharides with enhanced biotolerance used for encapsulating the cargo drug molecules, when loaded on the nanoparticle surface presents a perspective drug delivery system combining the physiological benevolence of the former and theranostic/efflux pump evading features of the latter. The present commentary highlight the importance of metal nanoparticle-loaded polysaccharides as perspective drug delivery system.