Macromolecular Bioscience

Cover: The cover features the first demonstration of interfacing the living yeast cells with graphene nanosheath. The versatile layer-by-layer assembly will allow the potential of integrating new physical and chemical functions for living cells while preserving their viability. Further details can be found in the article by S. H. Yang, T. Lee, E. Seo, E. H. Ko, I. S. Choi,* and B.-S. Kim* on page 61.

This issue of Macromolecular Bioscience contains articles of the Special Series “Advanced Polymers in Stem Cell Biology & Medicine”.

Cellular substrates containing well-defined mechanical properties, topographical features and micro-contacted printed adhesive regions are described and evaluated for pattern fidelity as a function of polymer formulation. The effect of substrate mechanical properties on contact guidance is explored.

TSDAIE is a dextran-based, biodegradable, temperature-sensitive polymer developed as a substrate for cell detachment to improve current stem cell culture techniques. At temperatures higher than its lower critical solution temperature (LCST), TSDAIE is hydrophobic and facilitates cell attachment. When TSDAIE is cooled to temperatures below its LCST, TSDAIE is hydrophilic and promotes cell detachment.

DNA and proteins use a variety of noncovalent interactions (e.g., electrostatics, π-π stacking, hydrogen bonding, hydrophobic interactions) to assemble into quaternary structures. Today, researchers not only incorporate DNA nucleobases into monomers/polymers, but utilize electrostatics and hydrogen bonding to orthogonally functionalize a polymer backbone.

Recent studies on the design and preparation of polymeric hybrid nanomaterials as attractive siRNA carrier systems are described, highlighting diverse conjugation and formulation strategies for the incorporation of siRNA and imaging agents. The optimal modification sites of the siRNA, the types of crosslinker, and several kinds of inorganic materials are evaluated for the preparation of proper nanomaterials.

With combination self-assembly between β-sheet block copolypeptides and CNTs, peptide-decorated bioactive carbon nanotubes or simple bioactive β-sheet peptide nanoribbons can be constructed, depending on the force balance processes between two classes of competing forces during self-assembly. This can be important in the fabrication of bioactive peptide/CNT hybrids and in the control of protein-misfolding diseases.

Semitelechelic (ST) poly[N-(2-hydroxypropyl)methacrylamide]–trastuzumab conjugates are synthesized and evaluated in vitro. When conjugated, the ST backbone shows favorable characteristics of a potential novel drug delivery system that actively targets human epidermal growth factor receptor type 2 overexpressing tumors. The conjugate exhibits prolonged anticancer activity compared to free TRZ.

Interfacing living yeast cells with graphene nanosheaths is achieved via versatile LbL assembly. Oppositely charged GO nanosheets are coated alternatingly onto the individual yeast cells, preserving the viability of the yeast cells and affording a means of interfacing graphene with living yeast cells. The method allows to provide new physical and chemical functions for living cells.

Polylaminin is a biomimetic polymer of the protein laminin that is shown to be temperature-resistant and stable in a cellular environment. When neuronal cells isolated from embryonic brain cortex are platted on polyLM they extend very long neurites (red), which grow interwoven with the mesh formed by the polymer (green).

Complexes of recombinant silk molecules with tumor-homing peptides and plasmid DNA are designed for use as non-cytotoxic and target-specific gene carriers. It is shown that these bioengineered silk systems can serve as versatile and useful new platforms for non-viral gene delivery or drug delivery.

Star-shaped poly(ε-caprolactone)-b-poly(ethylene oxide) (TAPP-PCL-mPEO) amphiphilic copolymer with a tetrakis-(4-aminophenyl)-terminated porphyrin core are synthesized and could self-assemble into micelles. The in vivo real-time fluorescent imaging revealed that the micelles could accumulate at tumor site via the blood circulation in tumor-bearing mice. In vivo antitumor efficacy examinations indicated that the PTX-loaded micelles had significantly superior efficacy than Taxol.

Coupling of a novel multitargeted sunitinib analogue to NH₂-PAMAM-G3 dendrimers via the platinum (II)-based ULS yields a conjugate with retained pharmacological activity. It accumulates rapidly in the kidneys and provides high intrarenal drug levels that last for several days, making such conjugates promising for the development of novel therapeutics for the treatment of renal diseases.

Microfibrous materials that decrease the adhesion of pathogenic bacteria and exhibit good antibacterial activity are obtained by attachment of quaternized chitosan derivatives with alkyl substituents of different chain lengths to electrospun mats from maleic anhydride copolymers. These new materials are promising for applications such as wound dressings and antimicrobial filters.

Heparin-like structured macromolecules are synthesized and directly blended with poly(ethersulfone) to prepare flat-sheet membranes through liquid/liquid phase separation. The synthesized polymeric material retards blood clotting and the modified membrane exhibits good anticoagulant ability and blood compatibility due to the existence of the important functional groups SO₃H, COOH and OH.

A new method to prepare PU surfaces with resistance to non-specific protein adsorption and a high capacity to bind plasminogen from plasma is reported. A poly(OEGMA-co-HEMA) random copolymer is grafted to the PU by surface-initiated radical polymerization. The OEGMA provides effective protein resistance and the HEMA provides a high density of OH groups for attachment of lysine.