Effect of biomineralization ability on push-out strength of proroot mineral trioxide aggregate, mineral trioxide aggregate branco, and calcium phosphate cement on dentin: An In vitro evaluation

The use of bone graft materials is required for the treatment of bone defects damaged beyond the critical defect; therefore, injectable calcium phosphate cement (CPC) is actively used after surgery. The application of various polymers to improve injectability, mechanical strength, and biological function of injection-type CPC is encouraged. We previously developed a chitosan–PEG conjugate (CS/PEG) by a sulfur (VI) fluoride exchange reaction, and the resulting chitosan derivative showed high solubility at a neutral pH. We have demonstrated the CPC incorporated with a poly (ethylene glycol) (PEG)-grafted chitosan (CS/PEG) and developed CS/PEG CPC. The characterization of CS/PEG CPC was conducted using Fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD). The initial properties of CS/PEG CPCs, such as the pH, porosity, mechanical strength, zeta potential, and in vitro biocompatibility using the WST-1 assay, were also investigated. Moreover, osteocompatibility of CS/PEG CPCs was carried out via Alizarin Red S staining, immunocytochemistry, and Western blot analysis. CS/PEG CPC has enhanced mechanical strength compared to CPC, and the cohesion test also demonstrated in vivo stability. Furthermore, we determined whether CS/PEG CPC is a suitable candidate for promoting the osteogenic ability of Dental Pulp Stem Cells (DPSC). The elution of CS/PEG CPC entraps more calcium ion than CPC, as confirmed through the zeta potential test. Accordingly, the ion trapping effect of CS/PEG is considered to have played a role in promoting osteogenic differentiation of DPSCs. The results strongly suggested that CS/PEG could be used as suitable additives for improving osteogenic induction of bone substitute materials.

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Fabrication and evaluation of calcium phosphate cement scaffold with controlled internal channel architecture and complex shape

Proceedings of the Institution of Mechanical Engineers Part H Journal of Engineering in Medicine ◽

10.1243/09544119jeim302 ◽

2007 ◽

Vol 221 (8) ◽

pp. 951-958 ◽

Cited By ~ 8

Author(s):

X Li ◽

D Li ◽

B Lu ◽

L Wang ◽

Z Wang

Keyword(s):

Tissue Engineering ◽

Calcium Phosphate ◽

Calcium Phosphate Cement ◽

Complex Shape ◽

X Ray Diffraction ◽

X Ray ◽

Precise Control ◽

Internal Channel ◽

Channel Architecture

The ability to have precise control over internal channel architecture, porosity, and external shape is essential for tissue engineering. The feasibility of using indirect stereo-lithography (SL) to produce scaffolds from calcium phosphate cement materials for bone tissue engineering has been investigated. The internal channel architecture of the scaffolds was created by removal of the negative resin moulds made with SL. Scanning electron microscopy (SEM) showed highly open, well-interconnected channel architecture. The X-ray diffraction examination revealed that the hydroxyapatite phase formed at room temperature in the cement was basically stable up to 850 °C. There was no phase decomposition of hydroxyapatite, although the crystallinity and grain size were different. The ability of resulting structure to support osteoblastic cells culture was tested in vitro. Cells were evenly distributed on exterior surfaces and grew into the internal channels of scaffolds. To exploit the ability of this technique, anatomically shaped femoral supracondylar scaffolds with 300-800 μm interconnected channels were produced and characterized.

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