Polyelectrolyte Substrate Coating for Controlling Biofilm Growth at Solid–Air Interface

Abstract

consequences on human health [1,2] and industrial processes [3,4] as well as antibiotics resistance. [5] Various approaches to inhibition of biofilm formation and their eradication were developed. [6] Biofilm formation at an interface is determined by several pheno mena, e.g., the initial adhesion of single bacteria to the surface and the further biofilm growth and spreading due to cell proliferation and biopolymer production. [7] Therefore, surface energy and electrostatic interactions with the substrate are two key determinants of biofilm formation. On this basis, a common strategy to fight bacterial colonization is the functionalization of surfaces that are prone to biofilm fouling. [6,8] For instance, surface hydrophilization [9] and low surface energy strategies [10] were considered. Surface topology was also modified to influence bacterial colonization, as recently reviewed in detail. [11] Polyelectrolyte coatings allow changing the surface energy, charge, and mechanical characteristics of various substrates easily. [12,13] Therefore, polyelectrolyte assemblies are often considered for possible application as antibacterial coatings. However, understanding the fundamental principles of bacteria-surface interactions remains of high importance. [14][15][16] Due to the negative charges found on their external membrane, bacteria tend to tightly attach to positively charged surfaces. [17] It was demonstrated that biofilm spreading rate was decreasing with increasing strength of adhesion. [17] One possible explanation is that bacteria elongation preceding cell division is obstructed by strong electrostatic binding to the surface. [18] Besides this, it is also known that positively charged molecules (and poly cations to a greater extent) exhibit antibacterial properties due to their ability to disrupt membranes of bacterial cells. [19] In contrast, negatively charged surfaces provide less stable bacterial cell contact with the surface, [18] so that the initial adhesion step is difficult but further biofilm spreading meets less obstacle.In addition to help preventing healthcare and industryrelated issues, investigating biofilm formation is beneficial to understand the development of biological tissues, [20] cell adaptability, [21] and communication [22] since some morphogenesis principles are common with higher organisms' tissues. Furthermore, colonies and biofilms of non-pathogenic microorganisms are considered to be promising to design hybrid living materials [23][24][25][26][27] challenging to get synthetically. Revealing

Adaptation of Escherichia coli Biofilm Growth, Morphology, and Mechanical Properties to Substrate Water Content

“…Interestingly, enhanced buckling of E. coli AR3110 biofilms due to confined growth has recently been obtained independently of substrate stiffness by coating the agar surface with positively charged polyelectrolytes. 28 In this context, interfacial friction was proposed to result from physicochemical interactions between negatively charged bacteria and positively charged coatings.…”

“…Note that substrates with high water content have a higher compliance to the deformations induced by biofilm growth (Figure B and Figure S1), but these are likely screened by the reduced adhesion and friction forces resulting from the abundance of water at the surface, as suggested by the few but large delaminated buckles (Figure D). Interestingly, enhanced buckling of E. coli AR3110 biofilms due to confined growth has recently been obtained independently of substrate stiffness by coating the agar surface with positively charged polyelectrolytes . In this context, interfacial friction was proposed to result from physicochemical interactions between negatively charged bacteria and positively charged coatings.…”

A rotating bioreactor for the production of biofilms at the solid–air interface

“…Depending on the selected microorganism, however, another membrane variant might turn out to be even more efficient. Also, it is possible that applying a macromolecular coating to the membrane can further boost the biomass production of certain microbes by promoting their attachment to the membrane layer (Ryzhkov et al, 2021; Sarjit et al, 2015), but such modifications certainly would need to be optimized for each targeted microorganism.…”

Separation of motions and vibrational separation of fractions for biocide brass

“…Moreover, a very promising way to bacterial growth control is the usage of materials with gradient functions. Our scientific group previously suggested several model systems to programable material to control biological systems [14] , [35] , [36] , [37] . The critical factor is to find a material with dynamic properties that can be easily managed in situ to new-way materials [38] .…”