One-step vapor deposition of fluorinated polycationic coating to fabricate antifouling and anti-infective textile against drug-resistant bacteria and viruses

Abstract

The ongoing pandemic caused by the novel coronavirus has turned out to be one of the biggest threats to the world, and the increase of drug-resistant bacterial strains also threatens the human health. Hence, there is an urgent need to develop novel anti-infective materials with broad-spectrum anti-pathogenic activity. In the present study, a fluorinated polycationic coating was synthesized on a hydrophilic and negatively charged polyester textile via one-step initiated chemical vapor deposition of poly(dimethyl amino methyl styrene-co-1H,1H,2H,2H-perfluorodecyl acrylate) (P(DMAMS-co-PFDA), PDP). The surface characterization results of SEM, FTIR, and EDX demonstrated the successful synthesis of PDP coating. Contact angle analysis revealed that PDP coating endowed the polyester textile with the hydrophobicity against the attachment of different aqueous foulants such as blood, coffee, and milk, as well as the oleophobicity against paraffin oil. Zeta potential analysis demonstrated that the PDP coating enabled a transformation of negative charge to positive charge on the surface of polyester textile. The PDP coating exhibited excellent contact-killing activity against both gram-negative Escherichia coli and gram-positive methicillin-resistant Staphylococcus aureus, with the killing efficiency of approximate 99.9%. In addition, the antiviral capacity of PDP was determined by a green fluorescence protein (GFP) expression-based method using lentivirus-EGFP as a virus model. The PDP coating inactivated the negatively charged lentivirus-EGFP effectively. Moreover, the coating showed good biocompatibility toward mouse NIH 3T3 fibroblast cells. All the above properties demonstrated that PDP would be a promising anti-pathogenic polymeric coating with wide applications in medicine, hygiene, hospital, etc., to control the bacterial and viral transmission and infection.

Keywords: Antibacterial; Antifouling; Antiviral; Fluorinated hydrophobic polymer; Initiated chemical vapor deposition (iCVD); Polycationic coating.

Graphical abstract

Fig. 1

The one-step iCVD of the cationic and fluorinated P(DMAMS-co-PFDA) (PDP) coating on the surface of hydrophilic polyester textile. Compared with the pristine textile, the coating endowed the textile with hydrophobicity, oleophobicity, and thus antifouling ability; the coating was positively charged and inactivated the negatively charged bacteria and viruses on contact. The facile iCVD process can apply the potent antifouling, antibacterial, and antiviral coating to the anti-infective field.

Fig. 2

A schematic diagram of an iCVD system.

Fig. 3

Procedure for antiviral testing based on lentivirus-EGFP infection assay.

Fig. 4

(a) SEM images of the cross section of pristine textile fiber and PDP coating on the textile fiber. (b) FTIR spectra of PPFDA, PDP, and PDMAMS on the reference silicon wafer surface. (c) EDX elemental mapping of pristine textile and PDP coated textile.

Fig. 5

(a) PDP coating repels the adhesion of liquid drops including (1) blood, (2) paraffin oil, (3) honey, pH calibration buffer solutions at (4) pH 4.00, (5) pH 6.86, (6) pH 9.18, (7) coffee, and (8) milk, while the pristine polyester textile absorbs most liquids. (b) Contact angles of water and paraffin oil on the pristine textile, PPFDA and PDP coated textiles, demonstrating that PDP coating endowed polyester textile surface with hydrophobicity and oleophobicity.

Fig. 6

Zeta potentials of the pristine polyester textile, PPFDA and PDP coated textiles, gram-negative E. coli, gram-positive MRSA, and lentivirus-EGFP. The pristine polyester and PPFDA coated textiles were negatively charged. PDP coated textile was positively charged with the surface potential of + 23.2 mV. On the other hand, the zeta potentials of the bacteria and virus are negative.

Fig. 7

(a) Antibacterial behavior of pristine polyester textile, PPFDA and PDP coated textiles against gram-positive MRSA and gram-negative E. coli. (b) Log reduction of bacterial CFU on contact with PPFDA and PDP coatings (n = 3). (c) Inhibition zones of povidone-iodine (PVP-I) soaked textile as a release-killing control, pristine textile, PPFDA and PDP coated textiles against MRSA. There is no inhibition zone appearing in the PDP group, indicating the PDP coating kills bacteria on contact. (d) Morphology of MRSA and E. coli bacterial cells on the surfaces of pristine textile (left, intact bacterial cell envelopes) and PDP coating (right, damaged bacterial cell envelopes) observed by SEM.

Fig. 8

Antiviral activity of PPFDA and PDP coated textiles against lentivirus-EGFP. The virus-infected cells are in green fluorescence, indicating sample cannot inactivate viruses; the cells without green fluorescence demonstrating an excellent virucidal activity of PDP coated textile. The total cells are observed in bright field for comparison.

Fig. 9

In vitro biocompatibility toward mouse fibroblast NIH3T3 cells. LIVE/DEAD fluorescent images of cells in three groups: (a) TCPS control, (b) pristine textile, and (c) PDP coated textile. (d) Cell proliferation in three groups determined by Alamar Blue assay.