Cytokine induction of sol–gel-derived TiO₂ and SiO₂ coatings on metallic substrates after implantation to rat femur

Abstract

Material surface is a key determinant of host response on implanted biomaterial. Therefore, modification of the implant surface may optimize implant–tissue reactions. Inflammatory reaction is inevitable after biomaterial implantation, but prolonged inflammation may lead to adverse reactions and subsequent implant failure. Proinflammatory activities of cytokines like interleukin (IL)-1, IL-6, and tumor necrosis factor-alpha (TNF-α) are attractive indicators of these processes and ultimately characterize biocompatibility. The objective of the study was to evaluate local cytokine production after implantation of stainless steel 316L (SS) and titanium alloy (Ti6Al4V) biomaterials coated with titanium dioxide (TiO 2 ) and silica (SiO 2 ) coatings prepared by sol–gel method. Biomaterials were implanted into rat femur and after 12 weeks, bones were harvested. Bone–implant tissue interface was evaluated; immunohistochemical staining was performed to identify IL-6, TNF-α, and Caspase-1. Histomorphometry (AxioVision Rel. 4.6.3 software) of tissue samples was performed in order to quantify the cytokine levels. Both the oxide coatings on SS and Ti6Al4V significantly reduced cytokine production. However, the lowest cytokine levels were observed in TiO 2 groups. Cytokine content in uncoated groups was lower in Ti6Al4V than in SS, although coating of either metal reduced cytokine production to similar levels. Sol–gel TiO 2 or SiO 2 coatings reduced significantly the production of proinflammatory cytokines by local tissues, irrespective of the material used as a substrate, that is, either Ti6Al4V or SS. This suggests lower inflammatory response, which directly points out improvement of materials’ biocompatibility.

Enhanced cytocompatibility and osteoinductive properties of sol–gel-derived silica/zirconium dioxide coatings by metformin functionalization

“…30,31 Non-toxic effect of silica and zirconia layers was established using both in vitro and in vivo models. [32][33][34] Moreover, silica and zirconia sol-gel coatings were also recognized as biocompatible with osteoinductive potential. 34,35 In addition, we previously showed that hybrid sol-gel coating SiO 2 /ZrO 2 ameliorates the osteogenic differentiation of multipotent mesenchymal cells (MSCs) of both bone marrow and adipose tissue origin.…”

“…[32][33][34] Moreover, silica and zirconia sol-gel coatings were also recognized as biocompatible with osteoinductive potential. 34,35 In addition, we previously showed that hybrid sol-gel coating SiO 2 /ZrO 2 ameliorates the osteogenic differentiation of multipotent mesenchymal cells (MSCs) of both bone marrow and adipose tissue origin. 11 Combination of progenitor cells, capable of functional differentiation toward bone forming cells with osteoinductive SS316L matrices provides a promising strategy for bone tissue engineering and cellular delivery, thus opens range of new perspective of clinical applications in bone regeneration.…”

Precision-guided long-acting analgesia by hydrogel-immobilized bupivacaine-loaded microsphere

“…The expression of cytokines not only reflects the presence and intensity of the inflammation reaction, but also plays an important role in tissue damage and chronic pain. Therefore, these cytokines are attractive markers to estimate the tissue responses to the sustained release formulations 64 .…”

Biofunctional Elements Incorporated Nano/Microstructured Coatings on Titanium Implants with Enhanced Osteogenic and Antibacterial Performance

“…[53] Recently, Sr, Cu, and Si also have been incorporated on the Ti implants in the form of 3D or mesoporous structures using sol-gel route. [55][56][57][58][59]…”

“…[24,157] Moreover, the inflammatory response is demonstrated to reduce on the SiO 2 coatings. [57] Wang et al have reported that Si-incorporated NTs coating prepared by anodization and EBE methods improve spreading, osteogenesis, and differentiation of MC3T3-E1 cells. In particular, the sample with the largest amount of Si (5.93% Si) shows the best ALP activity, osteogenesis-related gene expression, and mineralization (Figure 11).…”