Olena Kudina

Highly Efficient Phase Boundary Biocatalysis with Enzymogel Nanoparticles

The enzymogel nanoparticle made of a magnetic core and polymer brush shell demonstrates a novel type of remote controlled phase-boundary biocatalysis that involves remotely directed binding to and engulfing insoluble substrates, high mobility, and stability of the catalytic centers. The mobile enzymes reside in the polymer brush scaffold and shuttle between the enzymogel interior and surface of the engulfed substrate in the bioconversion process. Biocatalytic activity of the mobile enzymes is preserved in the enzymogel while the brush-like architecture favors the efficient interfacial interaction when the enzymogel spreads over the substrate and extends substantially the reaction area as compared with rigid particles.

Invertible micellar polymer nanoassemblies target bone tumor cells but not normal osteoblast cells

Aim: To demonstrate the capability of the invertible micellar polymer nanoassemblies (IMAs) to deliver and release curcumin using the recently discovered mechanism of macromolecular inversion to treat bone tumor cells. Materials & Methods: The effect of IMA-mediated delivery of curcumin on osteosarcoma cell survival was investigated using MTS assays. To assess the effect of IMAs-delivered curcumin on osteosarcoma cell growth, fluorescence-activated cell sorting was performed. The uptake of micellar nanoassemblies was followed using confocal microscopy. Results & Discussion: IMAs-delivered curcumin is effective in blocking osteosarcoma cell growth. It decreases cell viability in human osteosarcoma (MG63, KHOS, and LM7) cells while having no effect on normal human osteoblast cells. It indicates that curcumin-loaded IMAs provide a unique delivery system targeted to osteosarcoma cells.

Host-guest interactions between a nonmicellized amphiphilic invertible polymer and insoluble cyclohexasilane in acetonitrile.

Host-guest interactions between cyclohexasilane (Si(6)H(12)) and amphiphilic invertible macromolecules based on PEG and sebacic acid in acetonitrile (neither a solvent for cyclohexasilane nor a support for the micellization of amphiphilic invertible macromolecules) have been investigated. Despite the extended conformation of the macromolecules and the absence of self-assembled polymeric domains, a macromolecular amphiphilicity itself contributes to localizing Si(6)H(12) by AIP and thus enables Lewis acid-base interactions between Si(6)H(12) and the AIP carbonyl groups. The obtained results demonstrate an interesting phenomenon in that insoluble Si(6)H(12) can be localized by AIP macromolecules in a medium that does not support the formation of polymeric domains.