Ultrathin Films by LbL Self-assembly for Biomimetic Coatings of Implants

The number of arthroplasties is rapidly increasing, but the ability of current biomaterials to mimic the natural environment of human tissues is very limited. It would be desirable to fabricate implant surface nanocoatings which recreate the main features of the biological interactions between the implant and the host tissue. Osseointegration is influenced by mechanical stability and biological stability and surface modification of implants at nanoscale level is a recognized method to favor it. In this respect the major problem is the incidence of implant infections on implant integration in the bone.

The work described here is focused on promoting osseointegration and reducing bacterial infections incidence on implanted biomaterials. We have used the Layer-by-Layer (LbL) self-assembly of Collagen I (Col) and Hyaluronic Acid (HA) to functionalize planar supports. LbL is an easy, versatile and affordable technique able to modify in a controlled way different kind of surfaces using opposite charged polyelectrolytes. Titanium substrates have been coated obtaining higher homogeneity and smoother surfaces with respect to pristine titanium. These coatings can be regarded as a first step for the development of more complex structures to modulate osteogenesis and avoid implant infections.