Covalent layer‐by‐layer assembly of polyethyleneimine multilayer for antibacterial applications

Abstract

Polyelectrolyte multilayer film (PMF) is conventionally fabricated by the layer-by-layer (LBL) assembly of a pair of oppositely charged polyelectrolytes on a substrate through electrostatic attractions. However, the lack of long-term stability of PMF under physiological conditions limits its application as antimicrobial coating in medical devices. In this study, a stable PMF composed of only polyethyleneimine (PEI) was constructed by covalent LBL deposition. First, the specific buildup of PEI during covalent LBL assembly was validated by UV-Vis absorption spectroscopy and atomic force microscopy. Second, silver (Ag) nanoparticles were incorporated into PEI multilayers through in situ reduction of Ag(+) by the pre-absorption of NaBH(4). It was also shown that the mass of Ag nanoparticle can be controlled by varying multilayer thickness and loading cycles. Bacterial live/dead assay showed that the PEI multilayers effectively killed Staphylococcus aureus and Escherichia coli upon contact formation. The inclusion of Ag nanoparticles in (PEI) film not only enhanced the antimicrobial property against adherent bacteria but also led to the inhibition of the bacteria growth in suspended culture via the long-term release of Ag(+) into the liquid medium.

Enzyme-responsive polyion complex (PIC) nanoparticles for the targeted delivery of antimicrobial polymers

“…PEI has been reported as an efficient antimicrobial against both Gram positive and Gram negative bacteria. 30 , 31 Its antimicrobial activity can be tuned as a function of its degree of branching and molecular weight. Moreover, PEI has been extensively applied as a starting material for the preparation of polyelectrolyte complexes.…”

Carbon nanotube-based antimicrobial biomaterials formed via layer-by-layer assembly with polypeptides

“…A few studies used amphiphiles to disperse SWNT within Langmuir-Blodgett films [64][65][66], but ours appears to be the first application to LbL films. A few reports of LbL strategies toward antimicrobial films have appeared, with the antimicrobial effect based on cationic polymers [17], silver nanoparticles [67], and various antibiotics [68][69][70]. However, approaches involving SWNT as the antimicrobial agent within an LbL film are rather rare.…”

A silver nanocomposite biomaterial for blood‐contacting implants

“…Nanoparticles have a high surface area to volume ratio that confers mechanical and chemical properties superior to those of the original materials 23. Nanosilver (NS), clusters of silver atoms that range in diameter of 1–100 nm, possess potent antibacterial properties thus making them a leading candidate in medical applications for conferring antimicrobial properties to tissue engineering constructs and biomedical materials 24–31. Medical devices which have utilized Silver nanoparticles or NS include surface coatings for both central venous32 and neurosurgical catheters,33 in the treatment of burns,34 as an additive in bone cement,35 and also in wound dressings 36.…”