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

Abstract

3D printing technologies are a promising approach to treat intra-oral bone defects, especially those with poor regenerative potential. However, there is a lack of evidence regarding the impact of internal design specifications on the bone regenerative potential. Here, an in silico approach to optimize the internal design of calcium phosphate-based scaffolds for bone regeneration is proposed. Based on an in silico model of neotissue formation, a gyroid 3D-printed scaffold is designed and manufactured using UV stereolithography of bioceramic materials. An orthogonal lattice structure 3D-printed scaffold and a particulate xenograft are used as control groups. The scaffolds are implanted subperiosteally under a shell on rat calvarium for 4 or 8 weeks and bone neoformation performances are investigated by nanofocus computed tomography and decalcified histology. After 8 weeks, the gyroid group is associated with a higher ingrowth potential of the bone and is characterized by signs of osteoinduction (newly formed bone islands). The bone to material contact is similar between the gyroid and the particulate groups. The present results reinforce this in silico modeling strategy to design calcium phosphate-based 3D scaffolds and the gyroid experimental internal architecture seems to be highly promising for intra-oral bone regeneration applications.

Multifunctional Hydroxyapatite Composites for Orthopedic Applications: A Review

“…The tissueengineered bone was observed to repair in situ mandibular bone defects in dogs, and Zhang et al 160 were able to reduce the compositing time for these scaffolds from 8 days to 2 days without affecting the in vivo osteogenesis. Using an in silico model, the growth of neotissue was simulated by Van Hede et al 161 for various lattice structures of a 3D-printed HAp scaffold; from this, it was optimized that an internal microporous structure with a pore size of 700 μm and a wall thickness of 200 μm showcased enhanced bone neoformation in a calvarial rat model. By taking into account these dimensions, a gyroid 3Dprinted HAp scaffold was designed and fabricated by UV stereolithography.…”

A review on the ceramic additive manufacturing technologies and availability of equipment and materials

“…The raw materials are costly because they depend on high-priced photosensitive materials [15]. Efforts have been made to reduce feedstock [200][201][202][203] Bone repair/tissue engineering Hydroxyapatite [204][205][206][207][208][209][210][211][212][213][214][215][216], TCP [217][218][219][220][221][222][223][224][225][226][227][228], Al 2 O 3 [229], biosilicate [230], baghdadite [231][232][233], wollastonite-diopside [234], Mgsubstituted wollastonite [235,236], hydroxyapatite+TCP [237][238][239][240][241][242], hydroxyapatite+akermanite [243], calcium phosphate+bioglass [54,…”

3D-Printing for Critical Sized Bone Defects: Current Concepts and Future Directions

“…In vitro assessments of SLA biocompatibility indicate that these scaffolds provide an environment conducive to osteogenic differentiation and proliferation of several different cell types, including human periosteal-derived stem cells [ 77 ], human mesenchymal stem cells [ 78 , 79 , 80 ], and human embryonic stem cells ( Table 1 ) [ 94 ]. In vivo, SLA-generated scaffolds have shown great success in promoting de novo bone formation, angiogenesis, and osseointegration of the scaffold into murine and rabbit calvarial defects [ 78 , 95 , 96 ]. Using a combination of poly(propylene fumarate) and diethyl fumarate (DEF) as starting materials for the SLA scaffold, Lee et al demonstrated that the addition of microspheres containing BMP-2 into the scaffold resulted in effective bone formation in murine calvarial defects [ 97 ].…”