Polymeric Smart Coating Strategy for Titanium Implants

Abstract

Hyaluronan based hydrogel coatings can mimic extracellular matrix components and incorporate growth factors that can be released during a progressive degradation while new tissue regenerates. This paper describes a structural characterization of a hydrogel coating made of modified hyaluronan polymers and how these coatings interact with bone morphogenetic protein-2 (BMP-2). Quartz crystal microbalance and neutron reflectivity measurements were used for in-situ, real-time measurements of the adsorption properties of polymers and proteins on smooth titanium oxide surfaces that mimic implant products in orthopedics. The adsorption of BMP-2 on a bare titanium oxide surface is compared to that on titanium oxide coated with different chemically modified hyaluronan, the most important being hyaluronan with bisphosphonate groups (HA-BP). The subsequent release of the BMP-2 from these hydrogel coatings could be triggered by calcium ions. The amount of adsorbed protein on the surfaces as well as the amount of released protein both depend on the type of hyaluronan coating. We conclude that HA-BP coated titanium oxide surfaces provide an excellent material for growth factor delivery in-vivo.

Self‐Healing Silk Fibroin‐Based Hydrogel for Bone Regeneration: Dynamic Metal‐Ligand Self‐Assembly Approach

“…Although pure SF biomaterials demonstrated limited osteoconductivity, [65][66][67] coating of mSF with bone conductive CaP and subsequent in situ assembly of the biomineralized microfibers with Am-HA-BP binder into an injectable hybrid hydrogel provided an implant that showed enhanced osteogenesis in vivo. Moreover, as it was reported previously, [68,69] BP groups linked to hydrogel networks impart adhesiveness of the material to both CaP and titanium surfaces, which is very promising in orthopedic applications. Especially, it corresponds to non-loadbearing bone regeneration applications with orthopedic cavities that can be easily filled with moldable and biodegradable biomaterials.…”

Aurore: new software for neutron reflectivity data analysis

“…between different regions of the modeled sample as described in the example given in x5.2. Methods based on the use of different layer representations (numerical distributions or analytical functions) are extremely important and efficient in the study of well defined systems (Schneck et al, 2013;Berts et al, 2014;Belička et al, 2015). However, these models are very difficult to generalize since they are usually built for a particular class of systems.…”

Additively Manufactured Semiflexible Titanium Lattices as Hydrogel Reinforcement for Biomedical Implants

“…Furthermore, the hydrogel layer surrounding the implant may provide a smoother transition between the metallic implant and the surrounding biological tissues, and by integrating growth factors or molecules they can enhance the implant integration with surrounding tissues. [46,53] This study demonstrates, for the first time, the possibility of combining the compressive strength of titanium lattices and the viscoelastic properties of soft hydrogels, generating a hybrid construct capable of supporting higher loads compared to pure hydrogel constructs while still maintaining viscoelastic properties.…”

“…Current efforts to reduce the stiffness of metallic lattice structures for biomedical implants are directed toward changing the material, the unit cell type, the porosity, [ 40 ] and the pore interconnectivity [ 45 ] to ensure osseointegration and to reduce the possibility of implant loosening. To improve tissue integration, biomedical implants have previously been coated with hydrogels [ 46 ] to provide better adhesion to surrounding tissues [ 47 ] and antibacterial protection. [ 48 ] Until now, embedding of titanium implants with hydrogels has only been reported with the manufacture of stiff, macroporous structures to be used for bone implants, [ 49,50 ] but the generation of hybrid structures composed of bulk hydrogels and thin L‐PBF‐manufactured reinforcement implants has not been reported in the literature yet.…”

“…Furthermore, the hydrogel layer surrounding the implant may provide a smoother transition between the metallic implant and the surrounding biological tissues, and by integrating growth factors or molecules they can enhance the implant integration with surrounding tissues. [ 46,53 ]…”