Quantification of Adhesion Force of Bacteria on the Surface of Biomaterials: Techniques and Assays

Abstract

Biomaterials associated infection (BAI) has been identified as one of the leading causes of failure of bioimplants. A failed implant requires revision surgery, which is about 20 times costlier and more painful than primary surgery. Infection starts from initial attachment of bacteria onto the surface of biomaterials followed by colonization and biofilm formation. Once a biofilm is developed the bacteria become resistant toward antibiotics. On account of microbial cell development, their metabolic activity and viability are strongly affected by the adhesion. Hence a thorough investigation warrants an in-depth understanding of the interfacial adhesion. Several methods such as plate-and-wash assay, spinning–disc assay, centrifugation assay, step-pressure technique, optical tweezers, atomic force microscopy (AFM) and nanoindentation are used for the measurement of the bacterial adhesion. Most of the aforementioned techniques are nonquantitative and provide only approximate values of adhesion forces. Techniques such as AFM and nanoindentation can quantify a wide range of force 10 pN to 1 μN and 1 nN to 10 μN respectively, and hence they are particularly useful for exact quantification of the adhesion force as well as adhesion strength of bacterial cells on various surfaces of biomaterials. In this review, we present a comparative study of the techniques available to measure the bacterial adhesion force and strength, discuss the use of AFM in adhesion force quantification in detail and conclude by hypothesizing that the AFM technique has an edge over other techniques for quantification of bacterial adhesion force.

Modeling Bacterial Adhesion to Unconditioned Abiotic Surfaces

“…While both methods have essentially the same advantages in terms of precise force and position control, the latter places fewer demands on the system itself. Therefore, AFM-based force spectroscopy with individual bacterial probes, termed single cell force spectroscopy (SCFS), is the method of choice for many researchers investigating adhesion properties of bacteria (Berne et al, 2018;Alam et al, 2019). The cells are immobilized at an AFM cantilever and moved toward and then away from a surface.…”

Effect of Schwertmannite Surface Modification by Surfactants on Adhesion of Acidophilic Bacteria

“…Cell-surface interaction forces can be determined using atomic force microscopy (AFM). The adhesion forces between sulfide minerals and acidophilic bacteria have been measured previously [8,[15][16][17]. The adhesion force between the AFM tip and the bacteria surface was in the range of 3.9 to 4.3 nN [18].…”

“…This means that if the interfacial energy (γ BS ) of the bacteria (B) and the mineral surface (S) is smaller than a sum of bacteria and liquid (γ BL ) and the mineral surface and liquid interface (γ SL ), the adhesion of the bacterial cell will be favored [8,9]. In other words, the degree of bacterial cell adhesion will increase as the difference in surface energy between the bacterial cell and the mineral surface decreases [10].…”

On the strong connection between nanoscale adhesion of Yad fimbriae and macroscale attachment of Yad-decorated bacteria to glycosylated, hydrophobic and hydrophilic surfaces

“…We emphasize still the probability of interactions occurrence between galactosyl-, mannosyland lactosyl-grafted AFM-probes concerns less than 20% of total force curves, which is 4 to 5 The latter surface concentration corresponds to a fully covered surface if assuming that all adhered bacteria adopt a lying cylindrical configuration at the substrate surface. To the best of our knowledge, the influence of substrate surface chemistry on bacterial adhesion has been rarely addressed both at the macroscopic and molecular scales 69,70 and the experimental results detailed in this work highlight the intimate connection between the nanoscale adhesion features of the Yad fimbriae and the resulting bacterial adhesion behavior. They therefore support numerous theoretical studies about the dependence of bacterial adhesion on surface chemistry 71-…”