In vitro and in vivo biocompatibility of calcium‐phosphate scaffolds three‐dimensional printed by stereolithography for bone regeneration

Abstract

Stereolithography (SLA) is an interesting manufacturing technology to overcome limitations of commercially available particulated biomaterials dedicated to intra-oral bone regeneration applications. The purpose of this study was to evaluate the in vitro and in vivo biocompatibility and osteoinductive properties of two calcium-phosphate (CaP)-based scaffolds manufactured by SLA three-dimensional (3D) printing. Pellets and macro-porous scaffolds were manufactured in pure hydroxyapatite (HA) and in biphasic CaP (HA:60-TCP:40). Physico-chemical characterization was performed using micro X-ray fluorescence, scanning electron microscopy (SEM), optical interferometry, and microtomography (μCT) analyses. Osteoblast-like MG-63 cells were used to evaluate the biocompatibility of the pellets in vitro with MTS assay and the cell morphology and growth characterized by SEM and DAPI-actin staining showed similar early behavior. For in vivo biocompatibility, newly formed bone and biodegradability of the experimental scaffolds were evaluated in a subperiosteal cranial rat model using μCT and descriptive histology. The histological analysis has not indicated evidences of inflammation but highlighted close contacts between newly formed bone and the experimental biomaterials revealing an excellent scaffold osseointegration. This study emphasizes the relevance of SLA 3D printing of CaP-based biomaterials for intra-oral bone regeneration even if manufacturing accuracy has to be improved and further experiments using biomimetic scaffolds should be conducted. K E Y W O R D Sbone regeneration, bone scaffold, histology, microtomography, stereolithography

3D‐Printed Synthetic Hydroxyapatite Scaffold With In Silico Optimized Macrostructure Enhances Bone Formation In Vivo

“…[40] The relatively low sintering temperature used in the present study allowed to produce experimental scaffolds with a surface topography rather close to the natural bone surface characteristics favourable for cell adhesion, anchoring and proliferation. [34,41,42] In vivo results obtained from the Nano-CT analysis highlighted the superior bone regenerative potential of the gyroid design with more newly formed bone inside the scaffold, especially in the highest parts of the scaffolds. This result emphasized, besides the pore size parameter, the critical role of the pore geometry and orientation when designing 3D scaffolds for bone regeneration applications.…”

Multi‐Dimensional Printing for Bone Tissue Engineering

“…• PTMC/nano HA [37] • PPF [38] • PEG [39] • HA/BCP/polyfunctional acrylic resins [40] • Bioactive glass/rigid resin/1,6-hexanediol diacrylate [41] • Mild conditions benefit the loading of biomolecules and cells • High fabrication accuracy • Can obtain complex internal structures • Photopolymer is needed • Defective biodegradation rates and biocompatibility…”

3D Printing of Micro- and Nanoscale Bone Substitutes: A Review on Technical and Translational Perspectives

“…To explore the feasibility of in-situ 3D printing for the treatment of diseases, such as bone and cartilage defects, Li et al 53 used SLA to print alginate gel scaffolds for the defects of humerus injury and found a strong osteogenic effect. Furthermore, Le Guéhennec et al 54 used SLA technology to print scaffolds to evaluate the biocompatibility and osteoinductive properties of hydroxyapatite (HA) and hydroxyapatite-tri calcium phosphate (HA-TCP) scaffolds in vivo and in vitro. The materials used for printing were mixtures of bioceramics and organic components (polyfunctional acrylic resin and photoinitiator) and the scaffolds were printed in the form of pellets.…”