Papers by Annelise Barron
bioRxiv (Cold Spring Harbor Laboratory), Oct 29, 2023
The rise of drug resistance has become a global crisis, with >1 million deaths due to resistant b... more The rise of drug resistance has become a global crisis, with >1 million deaths due to resistant bacterial infections each year. Pseudomonas aeruginosa, in particular, remains a serious problem with limited solutions due to complex resistance mechanisms that now lead to more than 32,000 multidrug-resistant (MDR) infections and over 2,000 deaths annually. While the emergence of resistant bacteria has become concerningly common, identification of useful new drug classes has been limited over the past 40+ years. We found that a potential novel therapeutic, the peptide-mimetic TM5, is effective at killing P. aeruginosa and displays sufficiently low toxicity for mammalian cells to allow for use in treatment of infections. Interestingly, TM5 kills P. aeruginosa more rapidly than traditional antibiotics, within 30-60 minutes in vitro, and is effective against a range of clinical isolates. In vivo, TM5 significantly reduced bacterial load in the lungs within 24 hours compared to untreated mice and demonstrated few adverse effects. Taken together, these observations suggest that TM5 shows promise as an alternative therapy for MDR P. aeruginosa respiratory infections.
Nature Communications, May 19, 2022
A major challenge in coronavirus vaccination and treatment is to counteract rapid viral evolution... more A major challenge in coronavirus vaccination and treatment is to counteract rapid viral evolution and mutations. Here we demonstrate that CRISPR-Cas13d offers a broad-spectrum antiviral (BSA) to inhibit many SARS-CoV-2 variants and diverse human coronavirus strains with >99% reduction of the viral titer. We show that Cas13d-mediated coronavirus inhibition is dependent on the crRNA cellular spatial colocalization with Cas13d and target viral RNA. Cas13d can significantly enhance the therapeutic effects of diverse small molecule drugs against coronaviruses for prophylaxis or treatment purposes, and the best combination reduced viral titer by over four orders of magnitude. Using lipid nanoparticle-mediated RNA delivery, we demonstrate that the Cas13d system can effectively treat infection from multiple variants of coronavirus, including Omicron SARS-CoV-2, in human primary airway epithelium air-liquid interface (ALI) cultures. Our study establishes CRISPR-Cas13 as a BSA which is highly complementary to existing vaccination and antiviral treatment strategies.
05AIChE: 2005 AIChE Annual Meeting and Fall Showcase, Dec 1, 2005
한국생물공학회 학술대회, Oct 1, 2004
Biointerphases, May 21, 2009
Numerous strategies exist to prevent biological fouling of surfaces in physiological environments... more Numerous strategies exist to prevent biological fouling of surfaces in physiological environments; the authors' strategy focuses on the modification of surfaces with poly-N-substituted glycine oligomers ͑polypeptoids͒. The authors previously reported the synthesis and characterization of three novel polypeptoid polymers that can be used to modify titanium oxide surfaces, rendering the surfaces resistant to adsorption of proteins, to adhesion of mammalian and bacterial cells, and to degradation by common protease enzymes. In this study, they investigated the effect of polypeptoid chain length on the antifouling properties of the modified surfaces. For these experiments, they used poly͑N-methoxyethyl͒ glycines with lengths between 10 and 50 repeat units and determined the influence of chain length on coating thickness and density as well as resistance to protein adsorption and cellular adhesion. Short-term protein resistance remained low for all polymers, as measured by optical waveguide light mode spectroscopy, while fibroblast adhesion after several weeks indicated reduced fouling resistance for the polypeptoid-modified surfaces with the shortest chain length polymer. Experimental observations were compared to predictions obtained from a molecular theory of polymer and protein adsorption. Good agreement was found between experiment and theory for the chain length dependence of peptoid grafting density and for protein adsorption as a function of peptoid grafting density. The theoretical predictions provide specific guidelines for the surface coverage for each molecular weight for optimal antifouling. The predictions show the relationship between polymer layer structure and fouling.
Microbiology spectrum, Jun 29, 2022
Staphylococcus aureus is one of the most common pathogens associated with infection in wounds. Th... more Staphylococcus aureus is one of the most common pathogens associated with infection in wounds. The current standard of care uses a combination of disinfection and drainage followed by conventional antibiotics such as methicillin. Methicillin and vancomycin resistance has rendered these treatments ineffective, often causing the reemergence of infection. This study examines the use of antimicrobial peptoids (sequence-specific poly-N-substituted glycines) designed to mimic naturally occurring cationic, amphipathic host defense peptides, as an alternative to conventional antibiotics. These peptoids also show efficient and fast (,30 min) killing of methicillin-susceptible S. aureus (MSSA) and methicillin-resistant S. aureus (MRSA) at low micromolar concentrations without having apparent cytotoxic side effects in vivo. Additionally, these novel peptoids show excellent efficacy against biofilm formation and detachment for both MSSA and MRSA. In comparison, conventional antibiotics were unable to detach or prevent formation of biofilms. One cationic 12mer, Peptoid 1, shows great promise, as it could prevent formation of and detach biofilms at concentrations as low as 1.6 mM. The use of a bioluminescent S. aureus murine incision wound model demonstrated clearance of infection in peptoid-treated mice within 8 days, conveying another advantage these peptoids have over conventional antibiotics. These results provide clear evidence of the potential for antimicrobial peptoids for the treatment of S. aureus wound infections. IMPORTANCE Staphylococcus aureus resistance is a consistent problem with a large impact on the health care system. Infections with resistant S. aureus can cause serious adverse effects and can result in death. These antimicrobial peptoids show efficient killing of bacteria both as a biofilm and as free bacteria, often doing so in less than 30 min. As such, these antimicrobials have the potential to alleviate the burden that Staphylococcus infections have on the health care system and cause better outcomes for infected patients.
Colloids and Surfaces B: Biointerfaces, May 1, 2007
A crucial aspect of developing a functional, biomimetic lung surfactant (LS) replacement is the s... more A crucial aspect of developing a functional, biomimetic lung surfactant (LS) replacement is the selection of the synthetic lipid mixture and surfactant proteins (SPs) or suitable mimics thereof. Studies elucidating the roles of different lipids and surfactant proteins in natural LS have provided critical information necessary for the development of synthetic LS replacements that offer performance comparable to the natural material. In this study, the in vitro surface-active behaviors of peptide-and peptoid-based mimics of the lung surfactant proteins, SP-B and SP-C, were investigated using three different lipid formulations. The lipid mixtures were chosen from among those commonly used for the testing and characterization of SP mimics-(1) dipalmitoyl phosphatidylcholine:palmitoyloleoyl phosphatidylglycerol 7:3 (w/w) (PCPG), (2) dipalmitoyl phosphatidylcholine:palmitoyloleoyl phosphatidylglycerol:palmitic acid 68:22:9 (w/w) (TL), and (3) dipalmitoyl phosphatidylcholine:palmitoyloleoyl phosphatidylcholine:palmitoyloleoyl phosphatidylglycerol:palmitoyloleoyl phosphatidylethanolamine:palmitoyloleoyl phosphatidylserine:cholesterol 16:10:3:1:3:2 (w/w) (IL). The lipid mixtures and lipid/peptide or lipid/peptoid formulations were characterized in vitro using a Langmuir-Wilhelmy surface balance, fluorescent microscopic imaging of surface film morphology, and a pulsating bubble surfactometer. Results show that the three lipid formulations exhibit significantly different surface-active behaviors, both in the presence and absence of SP mimics, with desirable in vitro biomimetic behaviors being greatest for the TL formulation. Specifically, the TL formulation is able to reach low-surface tensions at physiological temperature as determined by dynamic PBS and LWSB studies, and dynamic PBS studies show this to occur with a minimal amount of compression, similar to natural LS.
Biomacromolecules, Apr 10, 2009
Monodisperse protein polymers engineered by biosynthetic techniques are well suited to serve as a... more Monodisperse protein polymers engineered by biosynthetic techniques are well suited to serve as a basis for creating comb-like polymer architectures for biomaterial applications. We have developed a new class of linear, cationic, random-coil protein polymers designed to act as scaffolds for multivalent display. These polymers contain evenly spaced lysine residues that allow for chemical or enzymatic conjugation of pendant functional groups. Circular dichroism (CD) spectroscopy and turbidity experiments have confirmed that these proteins have a random coil structure and are soluble up to at least 65 °C. Cell viability assays suggest these constructs are non-toxic in solution up to a concentration of 100 μM. We have successfully attached a small bioactive peptide, a peptoid-peptide hybrid, a poly(ethylene glycol) (PEG) polymer, and a fluorophore to the protein polymers by chemical or enzymatic coupling, demonstrating their suitability to serve as multivalent scaffolds in solutions or as gels.
Advanced Science, Jun 21, 2023
Antimicrobial peptides (AMPs) are promising therapeutics in the fight against multidrug‐resistant... more Antimicrobial peptides (AMPs) are promising therapeutics in the fight against multidrug‐resistant bacteria. As a mimic of AMPs, peptoids with N‐substituted glycine backbone have been utilized for antimicrobials with resistance against proteolytic degradation. Antimicrobial peptoids are known to kill bacteria by membrane disruption; however, the nonspecific aggregation of intracellular contents is also suggested as an important bactericidal mechanism. Here,structure‐activity relationship (SAR) of a library of indole side chain‐containing peptoids resulting in peptoid 29 as a hit compound is investigated. Then, quantitative morphological analyses of live bacteria treated with AMPs and peptoid 29 in a label‐free manner using optical diffraction tomography (ODT) are performed. It is unambiguously demonstrated that both membrane disruption and intracellular biomass flocculation are primary mechanisms of bacterial killing by monitoring real‐time morphological changes of bacteria. These multitarget mechanisms and rapid action can be a merit for the discovery of a resistance‐breaking novel antibiotic drug.
OSTI OAI (U.S. Department of Energy Office of Scientific and Technical Information), Apr 20, 2004
The FASEB Journal, Apr 1, 2011
Journal of Orthopaedic Research, May 24, 2018
Periprosthetic joint infection (PJI) is a common complication after total joint arthroplasty lead... more Periprosthetic joint infection (PJI) is a common complication after total joint arthroplasty leading to severe morbidity and mortality. With an aging population and increasing prevalence of total joint replacement procedures, the burden of PJI will be felt not only by individual patients, but in increased healthcare costs. Current treatment of PJI is inadequate resulting in incredibly high failure rates. This is believed to be largely mediated by the presence of bacterial biofilms. These polymicrobial bacterial colonies form within secreted extracellular matrices, adhering to the implant surface and local tissue. The biofilm architecture is believed to play a complex and critical role in a variety of bacterial processes including nutrient supplementation, metabolism, waste management, and antibiotic and immune resistance. The establishment of these biofilms relies heavily on the quorum sensing communication systems utilized by bacteria. Early stage research into disrupting bacterial communication by targeting quorum sensing show promise for future clinical applications. However, prevention of the biofilm formation via early forced induction of the biofilm forming process remains yet unexplored.
Amino Acids, 2014
We identified six novel, genetically encoded peptides: four from pit vipers, collectively named v... more We identified six novel, genetically encoded peptides: four from pit vipers, collectively named vipericidins, and two from the elapid. These new venom-derived cathelicidins exhibited potent killing activity against a number of bacterial strains (S. pyogenes, A. baumannii, E. faecalis, S. aureus, E. coli, K. pneumoniae, and P. aeruginosa), mostly with relatively less potent hemolysis, indicating their possible usefulness as lead structures for the development of new anti-infective agents. It is worth noting that these South American snake venom peptides are comparable in cytotoxicity (e.g., hemolysis) to human cathelicidin LL-37, and much lower than other membrane-active peptides such as mastoparan 7 and melittin from bee venom. Overall, the excellent bactericidal profile of vipericidins suggests they are a promising template for the development of broadspectrum peptide antibiotics.
This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY
Springer eBooks, 2001
A novel, replaceable polymer matrix based on a new N-substituted acrylamide monomer Duramide™ has... more A novel, replaceable polymer matrix based on a new N-substituted acrylamide monomer Duramide™ has been synthesized for application in DNA separations by microchannel electrophoresis. The monomer was found to be more hydrophilic than both acrylamide and N, N-dimethylacrylamide (DMA). Polymers were synthesized by free radical polymerization in aqueous solution and characterized by tandem gel permeation chromatography — multi-angle laser light scattering. PolyDuramide™ exhibits good capillary-coating ability via adsorption from aqueous solution, efficiently suppressing electroosmotic flow (EOF) in a manner comparable to that of poly-N,N-dimethylacrylamide (PDMA). Under DNA sequencing conditions, adsorptive polyDuramide™ coatings proved to be stable and to maintain negligible EOF for over 600 hours of electrophoresis. Resolution of DNA sequencing fragments, particularly fragments > 500 bases, in the novel matrix generally improves with increasing polymer concentration and decreasing electric field strength. Using polyDuramide both as a separation matrix and as a dynamic coating in bare fused silica capillaries, the matrix can resolve over 620 bases of contiguous DNA sequence within about 3 hours. Within a glass chip, the same results could likely be achieved in ∼30 minutes. These results demonstrate the potential of the novel matrix for use in DNA separation, as well as proteins, by microchannel electrophoresis.
Electrophoresis, Sep 1, 2005
Effect of polymer matrix and glycerol on rapid single-strand conformation polymorphism analysis b... more Effect of polymer matrix and glycerol on rapid single-strand conformation polymorphism analysis by capillary and microchip electrophoresis for detection of mutations in K-ras gene We present the rapid single-strand conformation polymorphism (SSCP) analysis by capillary and microchip electrophoresis to detect the mutations in K-ras gene. Parameters that might affect the analysis of mutation in K-ras gene, such as the polymer and the additive in the sieving matrix, have been studied systematically. Under the optimal conditions, the analysis of seven mutants of K-ras gene could be finished within 10 min by capillary electrophoresis (CE). Furthermore, with the wild-type gene as the inner standard, the analysis accuracy of mutations could be improved. In addition, by studying the properties of polymer solutions, the matrix suitable for microchip electrophoresis was found, and the detection of mutations in K-ras gene could be further shortened to 1 min.
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Papers by Annelise Barron