Silica-gelatin hybrid sol-gel coatings: A proteomic study with biocompatibility implications

Abstract

Osseointegration, including the foreign body reaction to biomaterials, is an immune-modulated, multifactorial, and complex healing process in which various cells and mediators are involved. The buildup of the osseointegration process is immunological and inflammation-driven, often triggered by the adsorption of proteins on the surfaces of the biomaterials and complement activation. New strategies for improving osseointegration use coatings as vehicles for osteogenic biomolecules delivery from implants. Natural polymers, such as gelatin, can mimic Collagen I and enhance the biocompatibility of a material. In this experimental study, two different base sol-gel formulations and their combination with gelatin were applied as coatings on sandblasted, acid-etched titanium substrates, and their biological potential as osteogenic biomaterials was tested. We examined the proteins adsorbed onto each surface and their in vitro and in vivo effects. In vitro results showed an improvement in cell proliferation and mineralization in gelatin-containing samples. In vivo testing showed the presence of a looser connective tissue layer in those coatings with substantially more complement activation proteins adsorbed, especially those containing gelatin. Vitronectin and FETUA, proteins associated with mineralization process, were significantly more adsorbed in gelatin coatings.

Proteomic Analysis of Mesenchymal Stem Cells and Monocyte Co-Cultures Exposed to a Bioactive Silica-Based Sol–Gel Coating

“…In vivo, it has been shown MT increases the formation of new bone trabeculae with higher relative length and density than Ti. 26,27 However, as described by Araujo-Gomes et al, 17,28 MT does not induce changes ALP activity when compared to Ti, even though it increases the expression of IL-6 and osteocalcin (OCN) expression. In co-cultures, mainly collagens (CO5A1, CO3A1, CO6A1, CO6A2, CO1A2, CO1A1, CO6A3) were down-Table 4.…”

“…Martínez-Ibáñez et al characterized MT in vitro with human adipose tissue-derived mesenchymal stem cells (AMSCs) showing that the material increased calcium-rich deposit formation. In vivo, it has been shown MT increases the formation of new bone trabeculae with higher relative length and density than Ti. , However, as described by Araújo-Gomes et al, , MT does not induce changes ALP activity when compared to Ti, even though it increases the expression of IL-6 and osteocalcin (OCN) expression. In co-cultures, mainly collagens (CO5A1, CO3A1, CO6A1, CO6A2, CO1A2, CO1A1, CO6A3) were downregulated, while ALP was lower at 14 days.…”

Intrasurgical Protein Layer on Titanium Arthroplasty Explants: From the Big Twelve to the Implant Proteome

“…Although many publications describe how proteins condition bone healing, a deeper and detailed knowledge of cellular function including inflammation and osteointegration remains unclear for some of the identified proteins. Especially there are only a few studies trying to understand how defined types of biomaterials can influence the protein adsorption onto surfaces …”

Role of the Complement System in the Response to Orthopedic Biomaterials

“…The data imply that complement proteins, including C1, factor H, and C4b-binding protein, which were found to be enriched on the surface, crucially contributed to the fibrous capsule formation observed [ 84 ]. In contrast, the same group demonstrated that in case of an in vivo rabbit tibia implant, high levels of adsorbed complement proteins (C1q and factor D) to the coated titanium surface did not negatively affect osseointegration [ 85 ]. These studies show that detailed analysis of the implant-bound proteome and “complementome” might allow a prediction of the material’s behavior in vivo, which could be superior to current in vitro tests that do not sufficiently reflect the in vivo situation [ 86 ].…”