Dicarboxylate-Substituted Octacalcium Phosphates for Hydrogel Filling and Fabrication of Resorbable Ceramics

• Published in: Inorganic materials : applied research 2021-03, Vol.12 (2), p.421-432
• Main Authors: Tikhonov, A. A., Klimashina, E. S., Evdokimov, P. V., Kukueva, E. V., Biryukov, A. S., Putlayev, V. I., Scherbackov, I. M., Dubrov, V. E.
• Format: Article
• Language: English
• Subjects: Apatite; Buffer solutions; Calcium phosphates; Ceramics; Chemistry; Chemistry and Materials Science; Decomposition; Formability; Hydrogels; Hydroxyapatite; Industrial Chemistry/Chemical Engineering; Inorganic Chemistry; Materials for Human Life Support and Environmental Protection; Materials Science; Polyethylene glycol; Substitutes; Synthesis; Three dimensional printing
• ISSN: 2075-1133; 2075-115X
• DOI: 10.1134/S2075113321020441

The main features of the synthesis of carboxylate-substituted analogs of octacalcium phosphate Ca 8 (HPO 4 ) 2 (PO 4 ) 4 ·5H 2 O (OCP) by hydrolysis of brushite (CaHPO 4 ⋅2H 2 O) and tricalcium phosphate α‑Са 3 (РО 4 ) 2 (α-TCP) in buffer solutions based on the salts of succinic, adipic, and citric acids are summarized. The synthesis of succinate-substituted (Suc@OCP) and adipate-substituted (Adi@OCP) OCPs gives the powders with Ca 8 (HPO 4 ) 2 – x А x (PO 4 ) 4 ⋅ z H 2 O (А = Suc, Аdi) composition. Thermolysis of substituted OCPs results in a mixture of β-Са 3 (РО 4 ) 2 (β-TCP) and hydroxyapatite Са 10 (РО 4 ) 6 (ОН) 2 (HA). Thermolysis features include the absence of an apatite-like decomposition product of pure OCP and higher decomposition temperatures compared to the pure OCP. Suc@OCP and Adi@OCP powders were used for the filling of hydrogels based on polyethylene glycol diacrylate (PEGDA) for the creation of a deformable composite implant by a stereolithographic 3D printing method and for fabrication of biphasic TCP/HAp ceramics.