Effects of Programmed Local Delivery from a Micro/Nano‐Hierarchical Surface on Titanium Implant on Infection Clearance and Osteogenic Induction in an Infected Bone Defect

Abstract

The two major causes for implant failure are postoperative infection and poor osteogenesis. Initial period of osteointegration is regulated by immunocytes and osteogenic‐related cells resulting in inflammatory response and tissue healing. The healing phase can be influenced by various environmental factors and biological cascade effect. To synthetically orchestrate bone‐promoting factors on biomaterial surface, built is a dual delivery system coated on a titanium surface (abbreviated as AH‐Sr‐AgNPs). The results show that this programmed delivery system can release Ag+ and Sr2+ in a temporal‐spatial manner to clear pathogens and activate preosteoblast differentiation partially through manipulating the polarization of macrophages. Both in vitro and in vivo assays show that AH‐Sr‐AgNPs‐modified surface renders a microenvironment adverse for bacterial survival and favorable for macrophage polarization (M2), which further promotes the differentiation of preosteoblasts. Infected New Zealand rabbit femoral metaphysis defect model is used to confirm the osteogenic property of AH‐Sr‐AgNPs implants through micro‐CT, histological, and histomorphometric analyses. These findings demonstrate that the programmed surface with dual delivery of Sr2+ and Ag+ has the potential of achieving an enhanced osteogenic outcome through favorable immunoregulation.

Synergistic antibacterial activity of physical-chemical multi-mechanism by TiO2 nanorod arrays for safe biofilm eradication on implant

“…Fabrication of such surfaces fall into two categories, chemical methods based on the release of antimicrobial agents such as inorganic metal ions (Ag + , Cu 2+ , Zn 2+ , Mg 2+ , etc.) and organic antimicrobial agents and antibiotics [ [3] , [4] , [5] , [6] , [7] ] as well as physical approaches that produce special surface structures [ [8] , [9] , [10] , [11] ] that resist bacteria colonization but support cell adhesion and proliferation. Both techniques have advantages and drawbacks.…”

Modifying a 3D-Printed Ti6Al4V Implant with Polydopamine Coating to Improve BMSCs Growth, Osteogenic Differentiation, and In Situ Osseointegration In Vivo

“…As presented in Figure 1F , the water contact angle of 3D-PDA was obviously lower than that of the 3D group, which suggested that the surface of the 3D-PDA group had better hydrophilicity and higher SFE. Previous research finds that PDA contains many amino and hydroxyl aqueous functional groups, which can provide a hydrophobic surface with a hydrophilic group to improve the hydrophilicity of the biological materials ( Ku et al, 2010 ; Li et al, 2019 ). The hydrophilic surface is beneficial to the adhesion of extracellular matrix proteins and more RGD (R-arginine, G-glycine, D-aspartic acid) sequence sitesexposure, which has an essential role in osteoblast adhesion, propagation, and differentiation.…”

Strontium Functionalization of Biomaterials for Bone Tissue Engineering Purposes: A Biological Point of View

“…In vivo test on infected New Zealand rabbit femoral metaphysis defects demonstrated osteogenic property of AH-Sr-AgNPs implants. In conclusion, the dual delivery of Sr and Ag has the potential of achieving an enhanced osteogenic outcome through favorable immunoregulation [ 158 ].…”