Ultrathin, flexible, and transparent polymer multilayer composites for the protection of silver surfaces

Synthesis of multivalent fatty acid-conjugated antisense oligonucleotides: Cell internalization, physical properties, and in vitro and in vivo activities

Herein, we describe the design and synthesis of multi-conjugatable fatty acid monomer phosphoramidites and their conjugation to antisense oligonucleotides (ASOs). Multivalent long-chain fatty acid conjugation improved the cellular uptake of ASOs but decreased in vitro activity due to alterations in physical properties and cellular localization. In addition, multivalently fatty acid-conjugated ASOs showed different organ specificity compared with that of unconjugated ASO in in vivo experiment. Although optimization of the linker structure between the fatty acid moiety and the ASO may be required, divalent long-chain fatty acid conjugation provides a new approach to increase endocytosis, thereby potentially improving the activity of therapeutic ASOs.

Covalent layer-by-layer films: chemistry, design, and multidisciplinary applications

Covalent layer-by-layer (LbL) assembly is a powerful method used to construct functional ultrathin films that enables nanoscopic structural precision, componential diversity, and flexible design. Compared with conventional LbL films built using multiple noncovalent interactions, LbL films prepared using covalent crosslinking offer the following distinctive characteristics: (i) enhanced film endurance or rigidity; (ii) improved componential diversity when uncharged species or small molecules are stably built into the films by forming covalent bonds; and (iii) increased structural diversity when covalent crosslinking is employed in componential, spacial, or temporal (labile bonds) selective manners. In this review, we document the chemical methods used to build covalent LbL films as well as the film properties and applications achievable using various film design strategies. We expect to translate the achievement in the discipline of chemistry (film-building methods) into readily available techniques for materials engineers and thus provide diverse functional material design protocols to address the energy, biomedical, and environmental challenges faced by the entire scientific community.

Controlled Interfacial Permeation, Nanostructure Formation, Catalytic Efficiency, Signal Enhancement Capability, and Cell Spreading by Adjusting Photochemical Cross-Linking Degrees of Layer-by-Layer Films

Interfacial properties including permeation, catalytic efficiency, Raman signal enhancement capabilities, and cell spreading efficiencies are important features that determine material functionality and applications. Here, we propose a facile method to adjust the above-mentioned properties by controlling the cross-linking degrees of multilayer using a photoactive molecule. After treating the cross-linked films in basic solutions, films with different cross-linking degrees presented varying residue thicknesses and film morphologies. As a result, these different films possessed distinct molecular loading and release characteristics. In addition, gold nanoparticles (AuNPs) of different morphological traits were generated by redox reactions coupled with diffusion within these films. The AuNP-polyelectrolyte obtained from the polyelectrolyte films of the medium cross-linking degrees displayed the highest catalytic efficiency and signal enhancement capabilities. Furthermore, cells responded to the variation of film cross-linking degrees, and on the films with the highest cross-linking degree, cells adhered with the highest speed. We expect this report to provide a general interfacial material engineering strategy for material designs.

Layer-by-layer deposition of antifouling coatings on stainless steel via catechol-amine reaction

The PEI/P(DMA-co-PEGMEMA) multiple bilayer-coated surfaces can effectively reduce microfouling and macrofouling.