Grafting of architecture controlled poly(styrene sodium sulfonate) onto titanium surfaces using bio-adhesive molecules: Surface characterization and biological properties

Abstract

This contribution reports on grafting of bioactive polymers such as poly(sodium styrene sulfonate) (polyNaSS) onto titanium (Ti) surfaces. This grafting process uses a modified dopamine as an anchor molecule to link polyNaSS to the Ti surface. The grafting process combines reversible addition-fragmentation chain transfer polymerization, postpolymerization modification, and thiol-ene chemistry. The first step in the process is to synthetize architecture controlled polyNaSS with a thiol end group. The second step is the adhesion of the dopamine acrylamide (DA) anchor onto the Ti surfaces. The last step is grafting polyNaSS to the DA-modified Ti surfaces. The modified dopamine anchor group with its bioadhesive properties is essential to link bioactive polymers to the Ti surface. The polymers are characterized by conventional methods (nuclear magnetic resonance, size exclusion chromatography, and attenuated total reflection-Fourier-transformed infrared), and the grafting is characterized by x-ray photoelectron spectroscopy, time-of-flight secondary ion mass spectrometry, and quartz crystal microbalance with dissipation monitoring. To illustrate the biocompatibility of the grafted Ti-DA-polyNaSS surfaces, their interactions with proteins (albumin and fibronectin) and cells are investigated. Both albumin and fibronectin are readily adsorbed onto Ti-DA-polyNaSS surfaces. The biocompatibility of modified Ti-DA-polyNaSS and control ungrafted Ti surfaces is tested using human bone cells (Saos-2) in cell culture for cell adhesion, proliferation, differentiation, and mineralization. This study presents a new, simple way to graft bioactive polymers onto Ti surfaces using a catechol intermediary with the aim of demonstrating the biocompatibility of these size controlled polyNaSS grafted surfaces.

Review of titanium surface modification techniques and coatings for antibacterial applications

“…The "grafting to" strategy permits an indirect grafting thanks to anchor molecules (silane [114][115][116][117], catechol [118][119][120][121], phosphate [122][123][124][125]). It enables titanium functionalization with various molecules in order to confer customized properties (Scheme 2).…”

“…The first one is the direct polymerization from the substrate surface by using an initiator bringing a catechol group. Another approach is to functionalize a polymer with a molecule loading a catechol group and subsequently anchor the polymer onto the desired surface as used by Chouirfa et al [118] In a third type of approach, catechol is first anchored to the surface of TiO 2 , then, by click-reaction with a functionalized polymer, the latter is grafted onto the titanium surface [118]. Recently, Chouirfa [119] grafted polyNaSS (polyanion) onto titanium surfaces via a dopamine anchor and showed a positive response against S. aureus.…”

Additive manufacturing of Ti6Al4V alloy via electron beam melting for the development of implants for the biomedical industry

“… Functional polymers: poly (sodium styrene sulfonate (polyNaSS) [ 322 , 323 , 324 , 325 , 326 , 327 , 328 , 329 ] Grafting copolymerization (“grafting to”) In “grafting to,” the aim is to obtain an indirect graft on titanium surfaces (functionalization) with anchor molecules such as silanes, catechols, or phosphates. Silane [ 330 , 331 , 332 , 333 ] Catechol [ 334 , 335 , 336 , 337 ] Phosphates [ 338 , 339 , 340 , 341 ] Silanization: silane anchor Metal biomaterials are functionalized with biomolecules by means of a suitable chemical reaction with crosslinking agents. This allows the covalent attachment of peptides, proteins, and polymers using molecules such as alkoxysilane.…”

“…The catechol is anchored on the surface of the TiO 2 film, and then the functionalized polymer is grafted. PolyNaSS (polyanion) [ 334 ], [ 335 ] Dopamine with carboxymethyl chitosan or hyaluronic acid catechol [ 336 ] Antimicrobial peptide, Magainin I (Mag) [ 337 ] Phosphor-based anchor Phosphonates are covalently bonded on the substrates of metal oxides such as titanium dioxide and used as cross-linking agents. They are more stable than other agents (e.g., silanes).…”

Copolymerization of a Catechol and a Diamine as a Versatile Polydopamine-Like Platform for Surface Functionalization: The Case of a Hydrophobic Coating

“…Nonetheless, stable SAMs can only be obtained on certain substrates where the interaction between catechol and surface is strong enough for achieving a proper stabilization of the molecular monolayer. This is the case of some metal oxides, where a coordination bond is established [32,33,34]. If only weak interactions come into play, such as hydrogen bonding, electrostatic forces or π–π stacking, cooperativity between catechol moieties is essential for generating a stable thin film on the surface.…”