Multifunctional surfaces with biomimetic nanofibres and drug-eluting micro-patterns for infection control and bone tissue formation

Abstract

For long-term orthopaedic implants, the creation of a surface that is repulsive to bacteria while adhesive to tissue cells represents a promising strategy to control infection. To obtain such multifunctional surfaces, two possible approaches were explored to incorporate a model antibiotic, rifampicin (Rf), into the osteogenic polycaprolactone (PCL)/chitosan (CHS) biomimetic nanofibre meshes by (1) blending Rf into the electrospinning solutions and then electrospinning into nanofibres (i.e., Rf-incorporating fibres), or (2) depositing Rf-containing poly(D,L-lacticco-glycolic) acid (PLGA) micro-patterns onto the PCL/ chitosan nanofibre meshes via ink-jet printing (i.e., Rfeluting micro-pattern/fibre). Rapid release of Rf from both meshes was measured even though a relatively slower release rate was obtained from the Rf-eluting micro-pattern ones. Antibacterial assay with Staphylococcus epidermidis showed that both mesh surfaces could effectively kill bacteria and prevent biofilm formation. However, only Rf-eluting micro-pattern meshes favoured the attachment, spreading and metabolic activity of preosteoblasts in the cell culture study. Furthermore, the Rf-eluting micro-pattern meshes could better support the osteogenic differentiation of preosteoblasts by up-regulating the gene expression of bone markers (type I collagen and alkaline phosphatase). Clearly, compared to Rf-incorporating nanofibre meshes, Rf-eluting micro-patterns could effectively prevent biofilm formation without sacrificing the osteogenic properties of PCL/chitosan nanofibre surfaces. This finding provides an innovative avenue to design multifunctional surfaces for enhancing bone tissue formation while controlling infection.

Antibacterial activity of a new broad‐spectrum antibiotic covalently bound to titanium surfaces

“…Biomaterials have also been coated with antiseptics such as chlorhexidine and iodine, with promising results . In addition, the coating of implant surfaces with antibiotics has been explored . Although the latter coatings have proven their effectiveness, it remains important to develop coatings with new antibacterial agents, thereby lowering the risk of developing resistance.…”

Applications of nanomaterials in mechano-sensitive tissues

“…Rapid release of rifampicin from PCL / nanofibres meshes illustrated good antimicrobial resistance to Staphlycoccus epidermidis and prevented biofilm formation. The RF-incorporation nanofibre meshes did not sacrifice the osteogenic properties of the scaffolds showing up regulation of gene expression for preosteoblastic collagen type I and alkaline phosphatase (ALP) [70]. Strontium phosphate incorporation into nanofibres has also shown a potential material for bone tissue engineering.…”

Applications of nanparticle based drug delivery systems in bone tissue engineering

“…This drug-loaded nanofibre mesh not only prevented the biofilm formation, but also favoured the attachment, spreading and osteogenic differentiation of pre-osteoblasts by up-regulating the gene expression of bone markers. This drug-loaded nanofibre mesh provides a feasible multifunctional surface for enhancing bone tissue formation while controlling infection [60].…”