Topography‐Supported Nanoarchitectonics of Hybrid Scaffold for Systematically Modulated Bone Regeneration and Remodeling

Abstract

Orthopedic implants should have sufficient strength and promote bone tissue regeneration. However, most conventional implants are optimized for use either under high mechanical load or for active osseointegration. To achieve the dual target of mechanical durability and biocompatibility, polyether ether ketone (PEEK) filaments reinforced with internal titanium dioxide (TiO2) nanoparticles via dopamine‐induced polymerization are additively manufactured into an orthopedic implant through material extrusion (ME). The exterior of the PEEK/TiO2 composite is coated with hydroxyapatite (HA) using radiofrequency (RF) magnetron sputtering to increase both the strength and biocompatibility provided by homogeneous ceramic–ceramic interactions and the protuberant nanoscale topography between the internal TiO2 nanoparticle reinforcement and external HA coating. The hardness, tensile, and compression, and scratch test results demonstrate a considerable enhancement in the mechanical strength of the hierarchical PEEK/TiO2/HA hybrid composite structure compared to that of the conventional 3D‐printed PEEK. Furthermore, PEEK with internal TiO2 reinforcement improves the proliferation and differentiation of bone cells in vitro, whereas the external HA coating leads to a more prevalent osteoblast absorption. Micro‐computed tomography and histological analyses confirm new bone formation and a high bone‐to‐implant contact ratio on the HA‐coated PEEK structure reinforced with TiO2 nanoparticles.

Chestnut-Inspired Hollow Hydroxyapatite 3D Printing Scaffolds Accelerate Bone Regeneration by Recruiting Calcium Ions and Regulating Inflammation

“…This mechanism prevents stress from passing through hydroxyapatite crystals, inhibiting crack propagation and ultimately enhancing the mechanical properties of the scaffold. 32,33 The results show that optimal osteoinductivity is achieved when the scaffold's pore size is controlled within the range of 200−500 μm, 34 and the porosity is maintained at 50−70%. 35 The hHAP/CS scaffolds with different concentration gradients, having pore sizes between 400 and 500 μm and porosity levels ranging from 50 to 80%, display favorable conditions.…”

Understanding the consolidation mechanism of selective laser sintering/powder bed selective laser process of ceramics: Hydroxyapatite case

“…Hydroxyapatite (HA) is an important ceramic material for biomedical applications (Grossin, 2021; Jang, 2022; Ahn, 2021). The production of calcium phosphate scaffolds through SLS has been largely studied (Grossin, 2021) for orthopedic implants.…”

A volatile microemulsion method of preparing water-soluble photo-absorbers for 3D printing of high-resolution, high-water-content hydrogel structures

“…14 Among all the 3D printing techniques, direct ink writing (DIW) is the most widely used technique for 3D printing hydrogels. 15–17 Different from DIW-based 3D printing that generates 3D structures by directly extruding viscous inks from printing nozzles, digital light processing (DLP)-based 3D printing fabricates 3D structures by projecting digitalized ultraviolet (UV) patterns to trigger localized photopolymerization that converts a liquid polymer resin to a solid 3D structure. 18,19 Due to the capability of manufacturing hydrogel structures with extremely high geometric resolution and complexity, DLP-based 3D printing has been successfully used in biomedical applications such as tissue engineering, 20 central nervous system regeneration, 21 cell-seeding scaffolds 22 and others.…”