Antibacterial coatings are rapidly emerging as a primary component of the global mitigation strategy of bacterial pathogens. Thanks to recent concurrent advances in materials science and ...biotechnology methodologies, and a growing understanding of environmental microbiology, an extensive variety of options are now available to design surfaces with antibacterial properties. However, progress towards a more widespread use in clinical settings crucially depends on addressing the key outstanding issues. We review release-based antibacterial coatings and focus on the challenges and opportunities presented by the latest generation of these materials. In particular, we highlight recent approaches aimed at controlling the release of antibacterial agents, imparting multi-functionality, and enhancing long-term stability.
To tackle antimicrobial resistance, a global threat identified by the United Nations, is a common cause of healthcare-associated infections (HAI) and is responsible for significant costs on ...healthcare systems, a substantial amount of research has been devoted to developing polysaccharide-based strategies that prevent bacterial attachment and biofilm formation on surfaces. Polysaccharides are essential building blocks for life and an abundant renewable resource that have attracted much attention due to their intrinsic remarkable biological potential antibacterial activities. If converted into efficient antibacterial coatings that could be applied to a broad range of surfaces and applications, polysaccharide-based coatings could have a significant potential global impact. However, the ultimate success of polysaccharide-based antibacterial materials will be determined by their potential for use in manufacturing processes that are scalable, versatile, and affordable. Therefore, in this review we focus on recent advances in polysaccharide-based antibacterial coatings from the perspective of fabrication methods. We first provide an overview of strategies for designing polysaccharide-based antimicrobial formulations and methods to assess the antibacterial properties of coatings. Recent advances on manufacturing polysaccharide-based coatings using some of the most common polysaccharides and fabrication methods are then detailed, followed by a critical comparative overview of associated challenges and opportunities for future developments.
Our review presents a timely perspective by being the first review in the field to focus on advances on polysaccharide-based antibacterial coatings from the perspective of fabrication methods along with an overview of strategies for designing polysaccharide-based antimicrobial formulations, methods to assess the antibacterial properties of coatings as well as a critical comparative overview of associated challenges and opportunities for future developments.
Meanwhile this work is specifically targeted at an audience focused on featuring critical information and guidelines for developing polysaccharide-based coatings. Including such a complementary work in the journal could lead to further developments on polysaccharide antibacterial applications.
Display omitted
Antibacterial coatings that eliminate initial bacterial attachment and prevent subsequent biofilm formation are essential in a number of applications, especially implanted medical devices. Although ...various approaches, including bacteria‐repelling and bacteria‐killing mechanisms, have been developed, none of them have been entirely successful due to their inherent drawbacks. In recent years, antibacterial coatings that are responsive to the bacterial microenvironment, that possess two or more killing mechanisms, or that have triggered‐cleaning capability have emerged as promising solutions for bacterial infection and contamination problems. This review focuses on recent progress on three types of such responsive and synergistic antibacterial coatings, including i) self‐defensive antibacterial coatings, which can “turn on” biocidal activity in response to a bacteria‐containing microenvironment; ii) synergistic antibacterial coatings, which possess two or more killing mechanisms that interact synergistically to reinforce each other; and iii) smart “kill‐and‐release” antibacterial coatings, which can switch functionality between bacteria killing and bacteria releasing under a proper stimulus. The design principles and potential applications of these coatings are discussed and a brief perspective on remaining challenges and future research directions is presented.
Responsive and synergistic antibacterial coatings that are responsive to the bacterial microenvironment, that possess two or more killing mechanisms that interact synergistically, or that have triggered‐cleaning capability have emerged as promising solutions for bacterial infection and contamination problems. The recent development of such coatings is summarized in this review.
Concrete biogenic corrosion (bio-corrosion) in wastewater pipes occurs mainly because of the diffusion of aggressive solutions and in situ production of sulfuric acid by sulfur-oxidizing ...microorganisms. The prevention of concrete bio-corrosion usually requires modification of the concrete mix or the application of a corrosion-resistant, chemical/antimicrobial-coating layer on the inner surface of the pipe to inhibit biological activity and provide a protective layer between the concrete surface and corrosive solution. However, the short bio-resistant lifetime due to undesired leaching of biocides to the surrounding environment coupled with the coating's poor acid-resistant properties have increased the requisite for safe, more efficient, environmentally friendly and long-lasting alternatives.
In this paper, three broad families of coating materials were investigated. These comprised Portland cement-based, geopolymer-based and geopolymer magnesium phosphate-based coatings. These three coatings carried in separate formulations, intermixed Zinc particle and Zinc-doped clay particles. These were in turn compared with ordinary cement-based coatings without Zinc or Zinc-doped clay. For the Zinc-doped clay particles, sodium-bentonite were impregnated with zinc ions to create a biocide-loaded carrier. The coatings’ chemical stability and resistance to biogenic corrosion were investigated by testing samples in an accelerated bio-corrosion chamber designed and developed by the authors. Variations in flexural strength were studied to evaluate the properties and performance of the coated samples after corrosion. Results show that the developed coating materials have significantly superior resistance to biogenic corrosion compared to ordinary cement-based coatings.
Illness as the result of ingesting bacterially contaminated foodstuffs represents a significant annual loss of human quality of life and economic impact globally. Significant research investment has ...recently been made in developing new materials that can be used to construct food contacting tools and surfaces that might minimize the risk of cross‐contamination of bacteria from one food item to another. This is done to mitigate the spread of bacterial contamination and resultant foodborne illness. Internet‐based literature search tools such as Web of Science, Google Scholar, and Scopus were utilized to investigate publishing trends within the last 10 years related to the development of antimicrobial and antifouling surfaces with potential use in food processing applications. Technologies investigated were categorized into four major groups: antimicrobial agent–releasing coatings, contact‐based antimicrobial coatings, superhydrophobic antifouling coatings, and repulsion‐based antifouling coatings. The advantages for each group and technical challenges remaining before wide‐scale implementation were compared. A diverse array of emerging antimicrobial and antifouling technologies were identified, designed to suit a wide range of food contact applications. Although each poses distinct and promising advantages, significant further research investment will likely be required to reliably produce effective materials economically and safely enough to equip large‐scale operations such as farms, food processing facilities, and kitchens.
Display omitted
•A novel blackberry-shape cationic copolymer particles (BsCCP) was applied to efficient antibacterial coating materials.•BsCCP, a typical blackberry-shape particle, was facilely ...synthesized via free-soap emulsion polymerization.•The quaternary ammonium salt was introduced into acrylate copolymer emulsion by covalent bonding method.•BsCCP could be used for rapidly and effectively resisting to the bacterial propagation.
The antibacterial materials are rapidly emerging as a primary component in mitigation of bacterial pathogens, and functional polymers play a vital role for the preparation of antibacterial coatings. In this study, using one-pot soap-free emulsion polymerization, we synthesized blackberry-shape cationic copolymer particles (BsCCP) with broad-spectrum antibacterial activity, and the BsCCP emulsion was added to the coating of the interior walls, which afforded BsCCP-based coating (BsCCP-C). The effects of surfactants, initiators, temperature, and monomer ratio on the synthesis of BsCCP were investigated. Besides, BsCCP was characterized by Fourier Transform infrared spectra (FT-IR), scanning electron microscope (SEM) and X-ray photoelectron spectroscopy (XPS). The antibacterial activities of BsCCP and BsCCP-C against Escherichia coli and Staphylococcus aureus were evaluated. BsCCP showed positive charge, high specific surface area and rough surface, which presented strong bactericidal activity. Its antibacterial mechanism was also discussed and demonstrated. To sum up, the BsCCP and BsCCP-C with high antibacterial activity showed great potential and was expected to be a candidate of antibacterial coating materials, which are able to use for rapidly and effectively resisting to the bacterial propagation.
We report on highly efficient, bioresponsive, controlled-release antibacterial coatings constructed by direct assembly of tannic acid (TA) with one of several cationic antibiotics (tobromycin, ...gentamicin, and polymyxin B) using the layer-by-layer (LbL) technique. These films exhibit a distinct “self-defense” behavior triggered by acidification of the immediate environment by pathogenic bacteria, such as Staphylococcus epidermidis (S. epidermidis) or Escherichia coli (E. coli). Films assembled using spin-assisted and dip-assisted techniques show drastically different morphology, thickness and pH-/bacteria-triggered antibiotic release characteristics. While dip-deposited films have rough surfaces with island-like, granular structures regardless of the film thickness, spin-assisted LbL assemblies demonstrate a transition from linear deposition of uniform 2D films to a highly developed 3D morphology for films thicker than ∼45 nm. Ellipsometry, UV–vis and mass spectrometry confirm that all coatings do not release antibiotics in phosphate buffered saline at pH 7.4 for as long as one month in the absence of bacteria and therefore do not contribute to the development of antibiotic resistance. These films do, however, release antibiotics upon pH lowering. The rate of triggered release can be controlled through the choice of assembled antibiotic and the assembly technique (spin- vs dip-deposition) and by the spinning rate used during deposition, which all affect the strength of TA–antibiotic binding. TA/antibiotic coatings as thin as 40 nm strongly inhibit S. epidermidis and E. coli bacterial growth both at surfaces and in surrounding medium, but support adhesion and proliferation of murine osteoblast cells. These coatings thus present a promising way to incorporate antibacterial agents at surfaces to prevent bacterial colonization of implanted biomedical devices.
Bacterial contamination in implanted biomedical devices is a critical daily concern. The most used material for permanent implant in biomedical field is Ti6Al4V alloy due to its beneficial mechanical ...properties and high biocompatibility. Accordingly, in this work different polymeric antibacterial coatings poly(N-vinyl pyrrolidone) (PVP), hyaluronic acid (HA) and chitosan (CHI) were developed and comparatively analysed for Ti6Al4V surface covering. The adhesion of these coatings to Ti6Al4V substrates were carried out after the conjugation of these polymers with the so well-known bioadhesive properties of catechol (CA) anchor group. These surface modifications were characterized by X-ray photoelectronic spectroscopy, contact angle measurements and atomic force microscopy. In addition, the stability of CA-conjugated polymeric coatings was compared with the coatings formed with unconjugated polymers. Finally, the cytocompatibility and antibacterial properties against gram-positive and gram-negative strains on coated Ti6Al4V substrates were assessed confirming the effectiveness of these polymeric coatings against bacterial infections for future applications in protecting biomedical implants.
•PVP-CA, HA-CA and CHI-CA conjugates were synthetized to coat Ti6Al4V surfaces.•Coatings proved high stability during bacteria adhesion and proliferation crucial period.•Cytocompatibility and antibacterial properties of the polymeric coatings were demonstrated.
Abstract The therapeutic applications of silver nanoparticles (AgNPs) against biomedical device-associated infections (BAI), by local delivery, are encountered with risks of detachment, instability ...and nanotoxicity in physiological milieus . To firmly anchor AgNPs onto modified biomaterial surfaces through tight physicochemical interactions would potentially relieve these concerns. Herein, we present a strategy for hierarchical TiO2 /Ag coating, in an attempt to endow medical titanium (Ti) with anticorrosion and antibacterial properties whilst maintaining normal biological functions. In brief, by harnessing the adhesion and reactivity of bioinspired polydopamine, silver nanoparticles were easily immobilized onto peripheral surface and incorporated into interior cavity of a micro/nanoporous TiO2 ceramic coating in situ grown from template Ti. The resulting coating protected the substrate well from corrosion and gave a sustained release of Ag+ up to 28 d. An interesting germicidal effect, termed “trap-killing”, was observed against Staphylococcus aureus strain. The multiple osteoblast responses, i.e. adherence, spreading, proliferation, and differentiation, were retained normal or promoted, via a putative surface-initiated self-regulation mechanism. After subcutaneous implantation for a month, the coated specimens elicited minimal, comparable inflammatory responses relative to the control. Moreover, this simple and safe functionalization strategy manifested a good degree of flexibility towards three-dimensional sophisticated objects. Expectedly, it can become a prospective bench to bedside solution to current challenges facing orthopedics.
Display omitted
•Chitosan/moringa coating deposited on Mg substrate via electrophoretic deposition.•FTIR confirmed the presence of chitosan and moringa in the coatings.•Chitosan/moringa coating ...inhibited the growth of Gram-positive and Gram-negative bacterial.•Chitosan/moringa coating improve the corrosion resistance of bare Mg.
Moringa loaded chitosan coatings (coating thickness ∼10 µm) were deposited on Mg substrate via electrophoretic deposition (applied electric field = 15 V/cm and deposition time = 20 min). Scanning electron microscopy images of chitosan/moringa coatings confirmed that the deposited coatings are densely packed and uniform. The presence of chitosan and moringa in the coating was confirmed by Fourier transform infrared spectroscopy. The corrosion studies revealed that the degradation rate of bare Mg decreased ∼7 order of magnitude upon coating deposition. Furthermore, the potential release of moringa from coatings inhibited the growth of Staphylococcus aureus and Escherichia coli. The moringa loaded chitosan coatings presented suitable morphology, electrochemical properties, and antibacterial properties for potential application in orthopedic devices.
PDF
