Calcium-to-phosphorus releasing ratio affects osteoinductivity and osteoconductivity of calcium phosphate bioceramics in bone tissue engineering

Abstract

Calcium phosphate (Ca-P) bioceramics, including hydroxyapatite (HA), biphasic calcium phosphate (BCP), and beta-tricalcium phosphate (β-TCP), have been widely used in bone reconstruction. Many studies have focused on the osteoconductivity or osteoinductivity of Ca-P bioceramics, but the association between osteoconductivity and osteoinductivity is not well understood. In our study, the osteoconductivity of HA, BCP, and β-TCP was investigated based on the osteoblastic differentiation in vitro and in situ as well as calvarial defect repair in vivo, and osteoinductivity was evaluated by using pluripotent mesenchymal stem cells (MSCs) in vitro and heterotopic ossification in muscles in vivo. Our results showed that the cell viability, alkaline phosphatase activity, and expression of osteogenesis-related genes, including osteocalcin (Ocn), bone sialoprotein (Bsp), alpha-1 type I collagen (Col1a1), and runt-related transcription factor 2 (Runx2), of osteoblasts each ranked as BCP > β-TCP > HA, but the alkaline phosphatase activity and expression of osteogenic differentiation genes of MSCs each ranked as β-TCP > BCP > HA. Calvarial defect implantation of Ca-P bioceramics ranked as BCP > β-TCP ≥ HA, but intramuscular implantation ranked as β-TCP ≥ BCP > HA in vivo. Further investigation indicated that osteoconductivity and osteoinductivity are affected by the Ca/P ratio surrounding the Ca-P bioceramics. Thus, manipulating the appropriate calcium-to-phosphorus releasing ratio is a critical factor for determining the osteoinductivity of Ca-P bioceramics in bone tissue engineering.

Combination of a Synthetic Bioceramic Associated with a Polydioxanone-Based Membrane as an Alternative to Autogenous Bone Grafting

“…The expression of RUNX2 is present in pre-osteoblastic cells, which is a characteristic feature of the formation of new bone at the beginning of the inflammatory process since the differentiation and migration of osteoblastic cells to the bone repair region is underway [50][51][52][53][54]. The AUTOPT+PG group showed greater expression of this gene, with a statistical difference when compared to Plenum ® Osshp.…”

“…The expression of ALP is related to the beginning of the bone tissue mineralization process, so greater expression was observed in the control group when compared to the bioceramic graft [50]. Bone sialoprotein (IBSP) plays a fundamental role in the formation of bone tissue because, during the repair process, its expression influences the differentiation of stem cells into osteoblastic cells [50,61,62]. The group grafted with autogenous bone showed greater gene expression for new bone formation when likened to the PO+PG group.…”

Preparation of Ordered‐Porous Hydroxyapatite/ β‐Tricalcium Phosphate Composites and Assessment of Sustained Drug‐Release Performance

“…And achieve controlled release of drugs without affecting the pharmacological activity of drugs. [5] Therefore, the drug carrier was a major factor affecting efficacy. [6][7][8] A large number of biocompatibility experiments had proved that calcium phosphate-based bio-ceramics had attracted widespread attention as bone graft substitutes.Because their chem-ical and mineral composition closely resembles that of the mineral component of bone, they are potentially interesting candidates for bone repair surgery.…”

Preclinical evaluation of a new synthetic carbonate apatite bone substitute on periodontal regeneration in intrabony defects

“…Hydroxyapatite is well known for its stability, whereas β-tricalcium phosphate has a rather fast resorption rate. 26,27 Very recently, a novel synthetic carbonate apatite bone substitute has been introduced to the dental marked. [28][29][30][31][32] Preclinical data suggested that the carbonate apatite is only resorbed by osteoclasts, whereas hydroxyapatite is just very minimally resorbed and β-tricalcium phosphate is fast resorbed even in the absence of osteoclasts.…”

“…Synthetic biomaterials made of hydroxyapatite or β‐tricalcium phosphate are frequently used in the dental field. Hydroxyapatite is well known for its stability, whereas β‐tricalcium phosphate has a rather fast resorption rate 26,27 . Very recently, a novel synthetic carbonate apatite bone substitute has been introduced to the dental marked 28–32 .…”