A5062245193- Antimicrobial agents and applications
- Antimicrobial Peptides and Activities
- Polydiacetylene-based materials and applications
- Bacterial biofilms and quorum sensing
- Conducting polymers and applications
- Advanced Polymer Synthesis and Characterization
- Organic Electronics and Photovoltaics
- Polymer crystallization and properties
- Synthetic Organic Chemistry Methods
- Polymer Foaming and Composites
- Marine Biology and Environmental Chemistry
- Click Chemistry and Applications
- Photochromic and Fluorescence Chemistry
- Carbon dioxide utilization in catalysis
- Chemical Synthesis and Analysis
- Advanced Fluorescence Microscopy Techniques
- Analytical Chemistry and Sensors
- Fullerene Chemistry and Applications
- Polymer Surface Interaction Studies
- Graphene and Nanomaterials Applications
- biodegradable polymer synthesis and properties
- Phase Equilibria and Thermodynamics
- Analytical chemistry methods development
- Curcumin's Biomedical Applications
- Advanced biosensing and bioanalysis techniques
Rensselaer Polytechnic Institute
2017-2025
University of Michigan
2009-2017
Ann Arbor Center for Independent Living
2015
Institute of Mathematical Sciences
2013
Seoul National University
2010
University of California, Irvine
2009
University of Massachusetts Amherst
2009
James Cook University
2005
Cornell University
2005
Stony Brook University
2005
A library of amphiphilic random copolymers containing cationic and hydrophobic side chains were prepared by copolymerization amine-functionalized methacrylate monomers with various ratios an alkyl methacrylate. Primary or tertiary amine groups, quaternary ammonium utilized as the source charge in each copolymer series. The antimicrobial hemolytic activities these are reported, enabling a systematic assessment effect different groups exert on biological activity polymers. It was shown that...
The increasing prevalence of antibiotic-resistant bacterial infections, coupled with the decline in number new antibiotic drug approvals, has created a therapeutic gap that portends an emergent public health crisis.
Spin and valley degrees of freedom in materials without inversion symmetry promise previously unknown device functionalities, such as spin-valleytronics. Control material with electric fields (ferroelectricity), while breaking additional symmetries, including mirror symmetry, could yield phenomena where chirality, spin, valley, crystal potential are strongly coupled. Here we report the synthesis a halide perovskite semiconductor that is simultaneously photoferroelectricity switchable chiral....
Low molecular weight random copolymers bearing protonated primary amine groups and hydrophobic alkyl in the side chains were synthesized their activities against E. coli , S. aureus human red blood cells, epithelial carcinoma cells (HEp-2) quantified. The mole fraction of (f(alkyl)) length major determinants activities. Against activity was diminished as f(alkyl) increased from 0 to about 0.2, but then enhanced dramatically further. Activity continually with increasing f(alkyl). cytotoxicity...
Antimicrobial and hemolytic activities of amphiphilic random copolymers were modulated by the structure cationic side chain spacer arms, including 2-aminoethylene, 4-aminobutylene, 6-aminohexylene groups. Cationic with ethyl methacrylate (EMA) comonomer prepared a range fractions, library was screened for antimicrobial activities. Copolymers 4-aminobutylene chains showed an order magnitude enhancement in their activity relative to those 2-aminoethylene without causing adverse hemolysis. When...
Cationic, amphiphilic polymers are currently being used as antimicrobial agents that disrupt biomembranes, although their mechanisms remain poorly understood. Herein, membrane association and disruption by bearing primary, tertiary, or quaternary ammonium salt groups reveal the role of cationic group structure in polymer−membrane interaction. The dissociation constants to liposomes POPC were obtained a fluorometric assay, exploiting environmental sensitivity dansyl moieties polymer end...
Nickel-catalyzed chain-growth copolymerizations of thiophene and selenophene derivatives afforded well-defined π-conjugated copolymers with narrow molecular weight distributions, defined end-groups, specific sequences. In particular, a copolymer novel linear gradient sequence was prepared. Compared to the analogous block random copolymers, displayed unique optical thermal properties as well thin-film morphology. Moreover, exhibited an intermediate extent phase separation into thiophene-rich...
There is an urgent need for new antibiotics which are effective against drug‐resistant bacteria without contributing to resistance development. We have designed and developed antimicrobial copolymers with cationic amphiphilic structures based on the mimicry of naturally occurring peptides. These exhibit potent activity a broad spectrum including methicillin‐resistant Staphylococcus aureus no adverse hemolytic activity. Notably, these polymers also did not result in any measurable development...
The purpose of this Viewpoint is to discuss the molecular design principles that guide development synthetic antimicrobial polymers, especially those intended mimic structure host defense peptides (HDPs). In particular, we focus on principle "amphiphilic balance" as it relates some recently developed polyphosphoniums with somewhat atypical structure. We find fundamental concept amphiphilic balance still applicable these new but method achieve such unique. then briefly outline future...
Self-degradable antimicrobial copolymers bearing cationic side chains and main-chain ester linkages were synthesized using the simultaneous chain- step-growth radical polymerization of t-butyl acrylate 3-butenyl 2-chloropropionate, followed by transformation groups into primary ammonium salts. We prepared a series with different structural features in terms molecular weight, monomer composition, amine functionality, chain structures to examine effect polymer properties on their hemolytic...
Hemolysis induced by antimicrobial polymers was examined to gain an understanding of the mechanism polymer toxicity human cells. A series cationic amphiphilic methacrylate random copolymers containing primary ammonium groups as functionality and either butyl or methyl hydrophobic side chains have been prepared radical copolymerization. Polymers with 0−47 mol % in chains, relative total number monomeric units, showed activity but no hemolysis. The 65 27 displayed both hemolytic activity....
Cationic amphiphilic polymethacrylate derivatives (PMAs) have shown potential as a novel class of synthetic antimicrobials. A panel PMAs with varied ratios hydrophobic and cationic side chains were synthesized tested for antimicrobial activity mechanism action. The are to be active against pathogenic bacteria, including drug-resistant Staphylococcus aureus, compared the natural peptide magainin which did not display any same strain. selected 47–63% methyl groups in showed minimum inhibitory...
Polymeric synthetic mimics of antimicrobial peptides (SMAMPs) have recently demonstrated similar activity as natural (AMPs) from innate immunity. This is surprising, since polymeric SMAMPs are heterogeneous in terms chemical structure (random sequence) and conformation coil), contrast to defined amino acid sequence intrinsic secondary structure. To understand this better, we compare AMPs with a "minimal" mimic, well-characterized family polydisperse cationic methacrylate-based random...
We synthesized a combinatorial library of dendrons that display cluster cationic charges juxtaposed with hydrophobic alkyl chain, using the so-called "molecular umbrella" design approach. Systematically tuning generation number and chain length enabled detailed study structure–activity relationships in terms both content charges. These discrete, unimolecular compounds rapid broad-spectrum bactericidal activity comparable to antibacterial peptides. Micellization was examined by pyrene...
N95 respirator face masks serve as effective physical barriers against airborne virus transmission, especially in a hospital setting. However, conventional filtration materials, such nonwoven polypropylene fibers, have no inherent virucidal activity, and thus, the risk of surface contamination increases with wear time. The ability to protect infection can be likely improved by incorporating components that deactivate viruses on contact. We present facile method for covalently attaching...
Self-immolative polymers (SIMPs) are macromolecules that spontaneously undergo depolymerization into small molecules when triggered by specific external stimuli. We report here the first examples of antimicrobial SIMPs with potent, rapid, and broad-spectrum bactericidal activity. Their antibacterial hemolytic activities were examined as a function cationic functionality. Polymers bearing primary ammonium groups showed more potent activity against Escherichia coli, relative to tertiary...
A library of functionalized oligo(thiophene)s with precisely controlled chain length, regioregularity, sequence, and pendant moieties in the side chains was prepared by iterative convergent/divergent organometallic couplings. The cationic facially amphiphilic structures were designed to mimic salient physiochemical features host defense peptides (HDPs) while concurrently exerting a photodynamic mechanism antibacterial activity. In dark, oligothiophenes exert broad-spectrum rapid bactericidal...
Gradient sequence copolymers of 3-hexylthiophene (90 mol%) and 3-(6-bromohexyl)thiophene (10 were synthesized by catalyst transfer polycondensation. Post-polymerization conversion the side-chain bromides into azides subsequent Cu-catalyzed azide–alkyne cycloaddition installed C60-functional groups. Comparing blends poly(3-hexylthiophene) (P3HT) phenyl-C61-butyric acid methyl ester (PCBM) with without gradient copolymer additive revealed that, when was present, micron-scale phase separation...
Self-immolative polymers, which exert potent antibacterial activity with low hemolytic toxicity to red blood cells, are triggered unzip into small molecules by a chemical stimulus.
Intracortical microelectrodes are used with brain-computer interfaces to restore lost limb function following nervous system injury. While promising, recording ability of intracortical diminishes over time due, in part, neuroinflammation. As curcumin has demonstrated neuroprotection through anti-inflammatory activity, we fabricated a 300 nm-thick microelectrode coating consisting polyurethane copolymer and polyethylene glycol (PEG), denoted as poly(curcumin-PEG
A gradient sequence copolymer containing 3-hexylthiophene (3HT) and 3-(6-bromohexyl)thiophene (3BrHT) with a linear change in comonomer composition was synthesized via controlled, chain-growth semi-batch method. For comparison, random block copolymers the same molecular weight ratio (1 : 1) were prepared. All three exhibited similar (Mn ∼ 32 kDa), low dispersity (Đ < 1.2) high regioregularity (>99%), suggesting that any differences among can be attributed to different sequences. The optical...
Abstract The purpose of this Viewpoint is to discuss the molecular design principles that guide development synthetic antimicrobial polymers, especially those intended mimic structure host defense peptides (HDPs). In particular, we focus on principle “amphiphilic balance” as it relates some recently developed polyphosphoniums with somewhat atypical structure. We find fundamental concept amphiphilic balance still applicable these new but method achieve such unique. then briefly outline future...
Curcumin is a natural polyphenol that exhibits remarkable antioxidant and anti-inflammatory activities; however, its clinical application limited in part by physiological instability. Here, we report the synthesis of curcumin-derived polyesters release curcumin upon hydrolytic degradation to improve stability solubility conditions. was incorporated polymer backbone one-pot condensation polymerization presence sebacoyl chloride polyethylene glycol (PEG, Mn = 1 kDa). The thermal mechanical...