The preparation and application of calcium phosphate biomedical composites in filling of weight-bearing bone defects

Abstract

Nowadays, artificial bone materials have been widely applied in the filling of non-weight bearing bone defects, but scarcely ever in weight-bearing bone defects. This study aims to develop an artificial bone with excellent mechanical properties and good osteogenic capability. Firstly, the collagen-thermosensitive hydrogel-calcium phosphate (CTC) composites were prepared as follows: dissolving thermosensitive hydrogel at 4 °C, then mixing with type I collagen as well as tricalcium phosphate (CaP) powder, and moulding the composites at 37 °C. Next, the CTC composites were subjected to evaluate for their chemical composition, micro morphology, pore size, Shore durometer, porosity and water absorption ability. Following this, the CTC composites were implanted into the muscle of mice while the 70% hydroxyapatite/30% β-tricalcium phosphate (HA/TCP) biomaterials were set as the control group; 8 weeks later, the osteoinductive abilities of biomaterials were detected by histological staining. Finally, the CTC and HA/TCP biomaterials were used to fill the large segments of tibia defects in mice. The bone repairing and load-bearing abilities of materials were evaluated by histological staining, X-ray and micro-CT at week 8. Both the CTC and HA/TCP biomaterials could induce ectopic bone formation in mice; however, the CTC composites tended to produce larger areas of bone and bone marrow tissues than HA/TCP. Simultaneously, bone-repairing experiments showed that HA/TCP biomaterials were easily crushed or pushed out by new bone growth as the material has a poor hardness. In comparison, the CTC composites could be replaced gradually by newly formed bone and repair larger segments of bone defects. The CTC composites trialled in this study have better mechanical properties, osteoinductivity and weight-bearing capacity than HA/TCP. The CTC composites provide an experimental foundation for the synthesis of artificial bone and a new option for orthopedic patients.

Identification of Small-Molecule Inhibitors for Osteosarcoma Targeted Therapy: Synchronizing In Silico, In Vitro, and In Vivo Analyses

“…Through the micro-CT, we observed the more trabecular and cortical bone formation and restoration of basic structure in the area of bone defects compared to the control group. In addition, BV/TV has been used to measure tumor-induced osteolysis ( Ohba et al, 2014 ), we can also find that the value in Table 2 demonstrates decreased trabecular osteolysis and increased BMD in the experimental group, which showed that the material degraded in mice and induced tibial healing, and the bone repairing effects were consistent with our previous study ( Cheng et al, 2021 ), which indicated that our CTC composites and small-molecule inhibitors have good effects for the treatment of mouse osteosarcoma.…”

“…In addition, it can also be inferred that the properties of CTC composites are stable and have no side effects in mice since there was no significant immune response and inflammatory reaction in the heart, liver, spleen, lung, kidney, and the muscle tissues adjacent to cancer tissues. Micro-CT scanning is an effective way to evaluate the effect of bone repair (Kim et al, 2021;Oliviero In addition, BV/TV has been used to measure tumorinduced osteolysis (Ohba et al, 2014), we can also find that the value in Table 2 demonstrates decreased trabecular osteolysis and increased BMD in the experimental group, which showed that the material degraded in mice and induced tibial healing, and the bone repairing effects were consistent with our previous study (Cheng et al, 2021), which indicated that our CTC composites and small-molecule inhibitors have good effects for the treatment of mouse osteosarcoma. Therefore, the CTC bio-composites were used to fill the defects caused by amputation, and the results showed the new bone tissues induced by the biomaterials repaired the bone defects very well.…”

“…Our previous experiments have proved that collagen-thermosensitive hydrogel–calcium phosphate (CTC) bio-composites have excellent osteoinductivity, osteoconductivity, and biological activity, which could be used for load-bearing bone repair. Furthermore, we also have previously demonstrated that the osteogenic ability of CTC is stronger than that of traditional calcium phosphate biomaterials, such as hydroxyapatite/tricalcium phosphate (HA/TCP) ( Cheng et al, 2021 ). Keeping these points in view, in this study, we explored a new approach of targeted therapy by combining surgery, biomaterials with small-molecule inhibitors by database screening, which could treat the mouse osteosarcoma constructed with 4-hydroxyaminoquinoline 1-oxide (4-HAQO).…”

Bone Tissue Engineering through 3D Bioprinting of Bioceramic Scaffolds: A Review and Update

“…Natural polymer materials include chitosan, alginate, and collagen, which have the advantages of good biocompatibility, no immunogenicity, and non-toxic degradation products ( Table 1 ). However, the mechanical properties of natural high molecular polymers are poor, and the degradation rate is too fast, so they are rarely used in the preparation of a single scaffold [ 24 , 25 , 26 ]. Artificial synthetic materials include polylactic acid, polylactic acid, and polycaprolactone (PCL).…”

Current Application of Beta-Tricalcium Phosphate in Bone Repair and Its Mechanism to Regulate Osteogenesis

“…Moreover, the BCP scaffolds presented a steady and moderate degradation rate with a compressive strength of 0.5 MPa in the presence of an acidic buffer solution (pH 5.5), which was demonstrated to be more beneficial for hMSCs adhesion, proliferation, and bone metabolism activity (Stastny et al, 2019). Furthermore, Cheng et al fabricated 25% collagen-15% thermosensitive hydrogel-60% β-TCP (CTC) composite scaffolds, which were showed to have better mechanical properties, osteoinductivity and weightbearing capacity than 70% HA/30% β-TCP composite scaffolds when implanted into tibia defect in mice (Cheng et al, 2021).…”