Core–Shell Structured Porous Calcium Phosphate Bioceramic Spheres for Enhanced Bone Regeneration

Abstract

Adequate new bone regeneration in bone defects has always been a challenge as it requires excellent and efficient osteogenesis. Calcium phosphate (CaP) bioceramics, including hydroxyapatite (HA) and biphasic calcium phosphates (BCPs), have been extensively used in clinical bone defect filling due to their good osteoinductivity and biodegradability. Here, for the first time, we designed and fabricated two porous CaP bioceramic granules with core−shell structures, named in accordance with their composition as BCP@HA and HA@BCP (core@shell). The spherical shape and the porous structure of these granules were achieved by the calcium alginate gel molding technology combined with a H 2 O 2 foaming process. These granules could be stacked to build a porous structure with a porosity of 65−70% and a micropore size distribution between 150 and 450 μm, which is reported to be good for new bone ingrowth. In vitro experiments confirmed that HA@BCP bioceramic granules could promote the proliferation and osteogenic ability when cocultured with bone marrow mesenchymal stem cells, while inhibiting the differentiation of RAW264.7 cells into osteoclasts. In vivo, 12 weeks of implantation in a critical-sized femoral bone defect animal model showed a higher bone volume fraction and bone mineral density in the HA@BCP group than in the BCP@HA or pure HA or BCP groups. From histological analysis, we discovered that the new bone tissue in the HA@BCP group was invading from the surface to the inside of the granules, and most of the bioceramic phase was replaced by the new bone. A higher degree of vascularization at the defect region repaired by HA@BCP was revealed by 3D microvascular perfusion angiography in terms of a higher vessel volume fraction. The current study demonstrated that the core−shell structured HA@BCP bioceramic granules could be a promising candidate for bone defect repair.

Engineered Cell‐Laden Armor Unit‐Mimicking Bioceramic Granules for Bone Regeneration

“…The formula is based on the previous study: weight loss (%) = (mass before soaking − mass after soaking)/mass before soaking × 100%. [50] Gene Expression: After 1, 4 and 7 days of coculture, the cells were isolated and centrifuged at 10 000 rpm at 4 °C for 5 min for RNA isolation and quantification. Briefly, total RNA was extracted using the RNeasy Mini Kit (Qiagen, Germany).…”

“…The formula is based on the previous study: weight loss (%) = (mass before soaking − mass after soaking)/mass before soaking × 100%. [ 50 ]…”

Effect of Hydroxyapatite on Alveolar Bone Regeneration in Various Dental Procedure: Systematic Review and Meta-Analysis

“…On the other hand, case reports, case series, and case control analyses were excluded, as well as studies lacking a control group or a comparison between the use of alloplastic material and other treatments. In vitro, animal, and non-clinical control studies were also excluded from the review (Vignesh et al, 2019;Wu et al, 2022).…”

Lineage-specific multifunctional double-layer scaffold accelerates the integrated regeneration of cartilage and subchondral bone

“…Additionally, a porous GelMA-based hydrogel containing calcium salt and thrombin was prepared to promote the rapid adsorption and coagulation of blood in the marrow cavity [ 18 ]. Moreover, calcium-containing hydrogels have been shown to stimulate the proliferation, differentiation and maturation of osteoblasts in vitro [ [23] , [24] , [25] ]. The haematoma formed can not only prevent later vascular invasion into the cartilage layer, which makes the cartilage unstable, but also accelerate bone survival.…”