Polymeric Materials with Antibacterial Activity: A Review

Abstract

Infections caused by bacteria are one of the main causes of mortality in hospitals all over the world. Bacteria can grow on many different surfaces and when this occurs, and bacteria colonize a surface, biofilms are formed. In this context, one of the main concerns is biofilm formation on medical devices such as urinary catheters, cardiac valves, pacemakers or prothesis. The development of bacteria also occurs on materials used for food packaging, wearable electronics or the textile industry. In all these applications polymeric materials are usually present. Research and development of polymer-based antibacterial materials is crucial to avoid the proliferation of bacteria. In this paper, we present a review about polymeric materials with antibacterial materials. The main strategies to produce materials with antibacterial properties are presented, for instance, the incorporation of inorganic particles, micro or nanostructuration of the surfaces and antifouling strategies are considered. The antibacterial mechanism exerted in each case is discussed. Methods of materials preparation are examined, presenting the main advantages or disadvantages of each one based on their potential uses. Finally, a review of the main characterization techniques and methods used to study polymer based antibacterial materials is carried out, including the use of single force cell spectroscopy, contact angle measurements and surface roughness to evaluate the role of the physicochemical properties and the micro or nanostructure in antibacterial behavior of the materials.

Keywords: antibacterial; biomedicine; food science; nanoparticles; polymers.

Figure 1

Scheme illustrating some areas of application of polymer antibacterial materials.

Figure 2

Illustration of the main antifouling strategies, as described by Kamperman et al. (Figure reproduced with permission from Reference [19]).

Figure 3

(Top) Schematic view of biofilm formation in different regions of a venous catheter. Microbial contamination may come from the catheter hub, the patient’s skin, due to the lack of skin antisepsis or from the bloodstream. (Bottom): Biofilm development and dispersal of bacteria or microcolonies.

Figure 4

Illustration on three approaches to endow a surface with antifouling properties: (1) modification of surface chemistry; (2) Surface topography; and (3) the architecture of the coating (Figure adapted with permission from Kamperman et al. [19]).

Figure 5

Jelly-inspired injectable hydrogel composite materials for guided tissue regeneration strategies. Before suture, under blue light excitation, sodium alginate hydrogel composite (CTP-SA) was activated to produce ROS to kill bacteria, achieving early debridement. After suture, under NIR irradiation, the photothermal effect of CTP-SA via the ROS recycle promote the osteogenesis (Reprinted with permission from Yingying Xu, Siyu Zhao, Zhenzhen Weng, Wei Zhang, Xinyi Wan, Tongcan Cui, Jing Ye, Lan Liao, and Xiaolei Wang ACS Applied Materials and Interfaces 2020 12 (49), 54497–54506 DOI: 10.1021/acsami.0c18070. Copyright 2020) [45].

Figure 6

Examples of 3D printed antibacterial prosthetic material with a commercial filament of PLA with 1–3% copper nanoparticles, PLACTIVE^TM (Image reproduced with permission from [54]).

Figure 7

Scheme summarizing the different kinds of packaging: conventional, active and smart or intelligent packaging.

Figure 8

(Top): Examples of sensors used to measure wrist pulse, finger bending and arm bending. (Bottom): Block diagram of the wireless bodily motion detection system (this figure was adapted with permission from the authors in Reference [82]).

Figure 9

Figure illustrating the mechanism of photoactivable polymers with visible light combined with QDs + CV.

Figure 10

Illustration of AgNPs loaded cotton fibers via a three-step method. The leaching out with water leads to a decrease in the number of particles due to poor binding (Reproduced with permission from Reference [113]).

Figure 11

Illustration of the main bactericidal mechanisms of nanopatterns, as described in Reference [150]. While the commonly believed theory is that bacterial cell wall is ruptured by penetration of high aspect ratio nanopatterns, a few studies suggest that EPS plays a key role. It has been shown that the strong attachment of EPS to the nanopatterns and the attempts of bacteria to move away from the unfavorable surface leads to cell membrane damage. Moreover, mechanotransduction pathways in which the mechanical forces affect the metabolomics, and the genomics of bacteria could be possible mechanisms of bacteria death on the surface. (Figure and Figure caption reproduced with permission from Reference [150]).

Figure 12

(a) Photographs associated to bacterial suspensions of a media containing an E-Coli strain co-cultured with chitin-silver nanoparticles, Ag-CNH. (b) Results of the evaluation of antibacterial activity obtained after measuring the optical density of the solutions at 600 nm. (Figure reproduced with permission from Reference [154].

Figure 13

(Top row) CLSM micrographs. Images show the results of the Live/dead assay on the uncoated silicone PDMS surface and surfaces coated with thiol, 2.4k V, and 2.4 k-S for E. Coli culture after 1 day. The surfaces were imaged under confocal laser scanning microscopy (green denotes live cells; red denotes dead cells; Scale bar = 20 µm). (Bottom row) FE-SEM images of E. coli after 1 day of incubation on uncoated and coated PDMS surfaces. Size of the scale bar: 10 μm. (Reproduced with permission from Reference [31]).

Figure 14

Schematic representation of bacterial nanomechanics experiments for (a) nanoindentation and (b), and (c) single-cell force spectroscopy (SCFS). In nanoindentation Table 2015. NanoTable 26. 062,001 [161].

Figure 15

Representative retraction force curves of S. epidermidis, S. xylosus, P. fluorescens, and E. coli single-cell probes and control probes (Cell-Tak-coated cantilevers) on three surfaces after contact for 10 s (Figure reproduced with permission from Langmuir 2014, 30, 14, 4019–4025 [162]).

Figure 16

Monitoring S. aureus cell division via AFM-IR. (A–D) AFM images of S. aureus cell showing the formation of septum preceding cell division. Size of imaged area: 2 × 2 µm. The images were selected from a larger series (12 images recorded every 20 min) and represent data recorded every 40 min. (E,F) AFM height and deflection image recorded at the end of cell septum formation with marked points of collection of AFM-IR spectra. Size of the imaged area 1.17 × 1.15 µm. The height of the newly formed structure is 45 nm. (G) AFM-IR spectra recorded from cell area (black) and septum area (red) (marked in (F)), in the range 1400–900 cm⁻¹. Both spectra were normalized to the amide I band and demonstrate an increase in the relative intensity of cell wall components from the septum. This figure is reproduced with permission from Kochan, K., Peleg, A. Y., Heraud, P., Wood, B. R. Atomic Force Microscopy Combined with Infrared Spectroscopy as a Tool to Probe Single Bacterium Chemistry. J. Vis. Exp. (163), e61728, doi:10.3791/61728 (2020) [163].

Figure 17

Scheme illustrating the different models used to interpret wettability behavior Young, Wenzel and Cassie-Baxter.