Multifunctional Coatings and Nanotopographies: Toward Cell Instructive and Antibacterial Implants

Abstract

In biomaterials science, it is nowadays well accepted that improving the biointegration of dental and orthopedic implants with surrounding tissues is a major goal. However, implant surfaces that support osteointegration may also favor colonization of bacterial cells. Infection of biomaterials and subsequent biofilm formation can have devastating effects and reduce patient quality of life, representing an emerging concern in healthcare. Conversely, efforts toward inhibiting bacterial colonization may impair biomaterial–tissue integration. Therefore, to improve the long‐term success of medical implants, biomaterial surfaces should ideally discourage the attachment of bacteria without affecting eukaryotic cell functions. However, most current strategies seldom investigate a combined goal. This work reviews recent strategies of surface modification to simultaneously address implant biointegration while mitigating bacterial infections. To this end, two emerging solutions are considered, multifunctional chemical coatings and nanotopographical features.

High‐Aspect‐Ratio Nanostructured Surfaces as Biological Metamaterials

“…www.advmat.de www.advancedsciencenews.com the impact on cytoskeletal tension [104,236,258,392,[416][417][418] (for a comprehensive overview of this area, see the reviews of Dalby and co-workers). [9,10] Similar responses have subsequently been demonstrated using high-aspect-ratio titanium nanorods, [393] and polymer-based nano-and micropillars, [146,419] showing that both nanopits and nanostructures can trigger similar behaviors.…”

“…At the cell membrane, they can modulate the ability of cells to form focal adhesions, complex multi‐protein assemblies that span the membrane and provide a physical anchor between the cell and the outer environment . This effect may be particularly pertinent on substrates with nanoscale features (geometry or porosity) that are on a similar length scale to filopodia (nanoscale, environment‐sensing cell protrusions) or integrin receptors (transmembrane proteins that facilitate external binding) …”

“…Colonies of microorganisms form biofilms, a complex extracellular matrix of polymers and proteins. Biofilms can prevent the penetration of chemicals, rendering colonies highly resistant to antibiotic treatment . Integrating surface topography and chemical cues, by combining functional peptides with nanostructured surfaces, has been proposed as one solution to this problem .…”

“…[34,101,398] This effect may be particularly pertinent on substrates with nanoscale features (geometry or porosity) that are on a similar length scale to filopodia (nanoscale, environment-sensing cell protrusions) or integrin receptors (transmembrane proteins that facilitate external binding). [9,186,233,399] Silicon nanoneedles have been shown to directly reduce the formation of focal adhesions in human mesenchymal stem cells, and hence reduce cytoskeletal tension. [34] A similar reduction in focal adhesions has also been observed in human embryonic stem cells cultured on polymer nanotopographies.…”

“…[1] But irrespective of their use, all of these systems are ultimately governed and mediated by the fundamental biological mechanisms occurring at the cell membrane-nanostructure interface.We highlight results that have cross-field importance and where appropriate refer to a number of excellent perspectives and other reviews relevant to each field. [1][2][3][4][5][6][7][8][9][10][11] The wide range of application areas also come with an equally large variety of fabrication and characterization approaches. Hence, this review also Materials patterned with high-aspect-ratio nanostructures have features on similar length scales to cellular components.…”