Recombinant spider silk coatings functionalized with enzymes targeting bacteria and biofilms

Abstract

Bacteria forming biofilms on surgical implants is a problem that might be alleviated by the use of antibacterial coatings. In this article, recombinant spider silk was functionalized with the peptidoglycan degrading endolysin SAL‐1 from the staphylococcal bacteriophage SAP‐1 and the biofilm‐matrix‐degrading enzyme Dispersin B from Aggregatibacter actinomycetemcomitans using direct genetic fusion and/or covalent protein–protein fusion catalyzed by Sortase A. Spider silk assembly and enzyme immobilization was monitored using quartz crystal microbalance analysis. Enzyme activity was investigated both with a biochemical assay using cleavage of fluorescent substrate analogues and bacterial assays for biofilm degradation and turbidity reduction. Spider silk coatings functionalized with SAL‐1 and Disperin B were found to exhibit bacteriolytic effect and inhibit biofilm formation, respectively. The strategy to immobilize antibacterial enzymes to spider silk presented herein show potential to be used as surface coatings of surgical implants and other medical equipment to avoid bacterial colonization.

Host Systems for the Production of Recombinant Spider Silk

“…Silicone implants coated with a recombinant spider silk protein were shown by Zeplin and co-workers to prompt a reduced inflammatory response in a preclinical study in rats, suggesting that coating medical implants in silk may enhance their biocompatibility [73]. More recently, recombinant spider silks functionalised with peptidoglycan degrading enzymes were reported to exhibit a bacteriolytic effect and prevent biofilm formation, further highlighting the materials potential as a coating for surgical implants [74]. Recombinant silk is also an effective biomaterial for use in drug delivery.…”

Targeting biofilms using phages and their enzymes

“…Manufacturing antimicrobial surfaces coated with endolysins and matrix-degrading enzymes is possible to obtain new materials, for example, bioengineered spider silk intended for drug-free sutures for reducing post-implantation infections [64]. All this evidence has led to propose phage lysins as novel antimicrobials to be used in the clinic, and as disinfectants for application in various branches of the economy such as the food industry [65].…”

Recent Progress of Spider-Silk-Inspired Adhesive Materials

“…This drug-free silk suture shows excellent antibacteria adhesion toward Gram-positive Staphylococcus aureus ( S. aureus ) and Gram-negative Escherichia coli ( E. coli ). Moreover, the recombinant spider silk protein could also be functionalized with the peptidoglycan degrading endolysin SAL-1 and the biofilm-matrix-degrading enzyme Dispersin B (DspB) to realize the bactericidal properties and inhibit biofilm formation, simultaneously In addition to the abilities to promote cell adhesion and differentiation, spider-silk-inspired adhesive materials were also used to achieve anticell or antimicroorganism adhesion. …”