Enhancing Separation and Mechanical Performance of Hybrid Membranes through Nanoparticle Surface Modification.

Membranes with selective gas transport properties and good mechanical integrity are increasingly desired to replace current energy intensive approaches to gas separation. Here, we report on the dual enhancement of transport and mechanical properties of hybrid cross-linked poly(ethylene glycol) membranes with aminopropyl-modified silica nanoparticles. CO permeability in hybrid membranes exceeds what can be predicted by Maxwell's equation and surpasses values of the pure polymer.

Surface Structure and Hydration of Sequence-Specific Amphiphilic Polypeptoids for Antifouling/Fouling Release Applications.

Amphiphilic polypeptoids can be designed with specific sequences of hydrophilic and hydrophobic units, which determine their surface properties for antifouling/fouling release purposes. Although the sequence-dependent surface structures of polypeptoids have been extensively investigated, e.g.

Sequence of Hydrophobic and Hydrophilic Residues in Amphiphilic Polymer Coatings Affects Surface Structure and Marine Antifouling/Fouling Release Properties.

Amphiphilic polymers, specifically combinations of hydrophilic and hydrophobic residues, have been shown to be effective as antifouling materials against the algae and diatoms. Here we use the inherent sequence specificity of polypeptoids made by solid-phase synthesis to show that the sequence of hydrophilic (methoxy) and hydrophobic (fluorinated) moieties affects both antifouling and fouling release of . The platform used to test these sequences was a polystyrene--poly(ethylene oxide--allyl glycidyl ether) (PS--P(EO--AGE)) scaffold, where the polypeptoids are attached to the scaffold using thiol-ene click chemistry.

Crosslinked linear polyethylenimine enhances delivery of DNA to the cytoplasm.

Crosslinked polyethylenimines (PEIs) have been frequently examined over the past decade since they can maintain the transfection efficiency of commercially available, 25k branched PEI, but exhibit less cytotoxicity. The argument is often made that the degradability of such polymers, generally synthesized with either disulfide or hydrolytically degradable crosslinkers, is critical to the high efficiency and low toxicity of the system. In this work, we present a crosslinked linear PEI (xLPEI) system in which either disulfide-responsive or non-degradable linkages are incorporated.

Effects of side group functionality and molecular weight on the activity of synthetic antimicrobial polypeptides.

The rapid emergence of antibiotic-resistant bacteria along with increasing difficulty in biofilm treatment has caused an immediate need for the development of new classes of antimicrobial therapeutics. We have developed a library of antimicrobial polypeptides, prepared by the ring-opening polymerization of γ-propargyl-L-glutamate N-carboxyanhydride and the alkyne-azide cycloaddition click reaction, which mimic the favorable characteristics of naturally occurring antimicrobial peptides (AmPs). AmPs are known not to cause drug resistance as well as prevent bacteria attachment on surfaces.