Synergistic Combination of Antimicrobial Peptides and Cationic Polyitaconates in Multifunctional PLA Fibers

Combining different antimicrobial agents has emerged as a promising strategy to enhance efficacy and address resistance evolution. In this study, we investigated the synergistic antimicrobial effect of a cationic biobased polymer and the antimicrobial peptide (AMP) temporin L, with the goal of developing multifunctional electrospun fibers for potential biomedical applications, particularly in wound dressing. A clickable polymer with pendent alkyne groups was synthesized by using a biobased itaconic acid building block. Subsequently, the polymer was functionalized through click chemistry with thiazolium groups derived from vitamin B1 (PTTIQ), as well as a combination of thiazolium and AMP temporin L, resulting in a conjugate polymer-peptide (PTTIQ-AMP). The individual and combined effects of the cationic PTTIQ, Temporin L, and PTTIQ-AMP were evaluated against Gram-positive and Gram-negative bacteria as well as Candida species. The results demonstrated that most combinations exhibited an indifferent effect, whereas the covalently conjugated PTTIQ-AMP displayed an antagonistic effect, potentially attributed to the aggregation process. Both antimicrobial compounds, PTTIQ and temporin L, were incorporated into poly(lactic acid) electrospun fibers using the supercritical solvent impregnation method. This approach yielded fibers with improved antibacterial performance, as a result of the potent activity exerted by the AMP and the nonleaching nature of the cationic polymer, thereby enhancing long-term effectiveness.This work was funded by the MICINN (PID2019-104600RB- I00 and PID2021-123553OA-I00), the Agencia Estatal de Investigación (AEI, Spain), and Fondo Europeo de Desarrollo Regional (FEDER, EU) and by CSIC (LINKA20364). A. Chiloeches acknowledges MICIU for his FPU fellowship FPU18/01776. Cesar de la Fuente-Nunez holds a Presidential Professorship at the University of Pennsylvania and acknowl- edges funding from the Procter & Gamble Company, United Therapeutics, a BBRF Young Investigator Grant, the Nemirovsky Prize, Penn Health-Tech Accelerator Award, and the Dean’s Innovation Fund from the Perelman School of Medicine at the University of Pennsylvania. Research reported in this publication was supported by the Langer Prize (AIChE Foundation), the National Institute of General Medical Sciences of the National Institutes of Health under award number R35GM138201, and the Defense Threat Reduction Agency (DTRA; HDTRA11810041, HDTRA1-21-1-0014, and HDTRA1-23-1-0001). D. Placha and J. Zagora acknowledge the Doctoral grant competition VSB-Technical University of Ostrava (reg. no. CZ.02.2.69/0.0/0.0/19_073/0016945) with- in the Operational Programme Research, Development and Education, under project DGS/INDIVIDUAL/2020-001 “Development of antimicrobial biobased polymeric material using supercritical fluid technology”

Effect of glycounits on the antimicrobial properties and toxicity behavior of polymers based on quaternized DMAEMA

Polymers with quaternary ammonium groups such as quaternized poly(2-(dimethylamino)ethyl methacrylate) (PDMAEMAQ) have been used as antimicrobial agents because of their demonstrated good antimicrobial activities against a huge number and types of microbes, although their cytotoxicity is also well known. In this work block copolymers based on PDMAEMAQ were synthesized containing hydrophobic segments of poly(butyl methacrylate) to improve the antimicrobial activity and glycomonomer units with the aim of decreasing the cytotoxicity of the polymers. Hydrophobic butyl methacrylate (BMA) blocks were chain extended by statistical and block copolymers of DMAEMA and 2-{[(D-glucosamin-2-N-yl)carbonylethyl methacrylate (HEMAGl) glycomonomer of different compositions. In order to find the balance between antimicrobial activity and cytotoxicity, the selectivity index of each polymer was obtained from minimum inhibitory concentrations (MIC) and white and red blood cells toxicity measurements

Antibacterial and compostable polymers derived from biobased itaconic acid as environmentally friendly additives for biopolymers

In this work, a series of antibacterial cationic copolymers derived from bio-sourced itaconic acid was studied as potential biobased active components in biodegradable formulations based on poly(butylene adipate-co-terephthalate) (PBAT) for packaging applications. These copolymers were first characterized by testing their antimicrobial activity against resistant bacterial strains, their biodegradability in compost conditions, and their thermal properties by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The antibacterial properties showed potent activity against Methicillin-resistant Staphylococcus aureus (MRSA), with MIC values as low as 78 μg mL 1. Related to their biodegradability, the cationic polymers biodegraded fast under compost conditions and even a priming effect was observed in the compost. Thermal properties, characterized by DSC and TGA, showed that the copolymers thermally degraded at temperature relatively low; nevertheless, they are able to be processed at temperatures up to ~150 ◦C. Subsequently, these antibacterial polymers were successfully blended as minor active component (10 wt%) with PBAT by melt-extrusion and press-compression molding. The resulting biopolymeric films exhibit potent antibacterial activity, which confirm that the cationic polymers incorporated as active component are able to perverse this activity after the processing and impart antibacterial properties to PBAT bioplastic. Therefore, these antibacterial biobased polymers derived from itaconic acid seem to be good candidates for applications related to active food packaging or even for biomedical devices.MICINNAgencia Estatal de Investigación (AEI, Spain)Fondo Europeo de Desarrollo Regional (FEDER, EU)CSICDepto. de Química OrgánicaFac. de Ciencias QuímicasTRUEpu

Functional surfaces obtained from emulsion polymerization using antimicrobial glycosylated block copolymers as surfactants

In this work, antimicrobial glycosylated block copolymers were successfully immobilized onto polymeric surfaces by using them as surfactants in butyl methacrylate emulsion polymerization. In particular several amphiphilic block copolymers of various compositions were employed, all consisting of a poly(butyl methacrylate) hydrophobic segment and a statistical copolymer containing quaternized trimethylaminoethyl methacrylate and 2-(D-glucosamin-2-N-yl)carbonylethyl methacrylate glycomonomer as a hydrophilic block. The influence of the antimicrobial polymeric surfactant structure and solid content on the emulsion polymerization was investigated in detail. It was demonstrated that the efficiency of the surfactant is highly dependent on the hydrophilic/hydrophobic balance; in general the surface-active properties get worse with an excess of hydrophilicity. Monodisperse and stable latexes stabilized with an antimicrobial polymeric surfactant were successfully obtained and then employed to form active films. The film formation process under thermal treatments was followed and confirmed by AFM. The surface functionality of the films was tested by analyzing the interaction of glycounits of the surface with Concanavalin A lectin by fluorescence spectroscopy. In addition, the antimicrobial capability of these films against Gram-positive bacteria and yeast was demonstrated whereas the leaching of the surfactants to the media was discarded. Graphical abstract: Functional surfaces obtained from emulsion polymerization using antimicrobial glycosylated block copolymers as surfactant