Controlling the degradation of dicalcium phosphate/calcium sulfate/poly(amino acid) biocomposites for bone regeneration

Ternary biocomposites of dicalcium phosphate (DCP), calcium sulfate (CS), and poly(amino acid) copolymer (PAA) could be used as a promising degradable biomimic bone substitute. Using an in vitro degradation model, we evaluated the influence of polymerization conditions, initial amino acids, and (DCP + CS)/PAA ratio on the degradation of the resulting materials. PAA degradation was affected by both the polymerization conditions and the initial amino acids, and the degradation of the DCP/CS/PAA composites was affected by the (DCP + CS)/PAA ratio. Using a certain initial amino acids (75% ε‐aminohexanoic acid, 19% γ‐aminobutanoic acid, 4% l‐proline, and 2% l‐lysine) and polymerization conditions (i.e., 210°C for 2.5 h) as the polymeric phase, (DCP + CS)/PAA biocomposites were prepared with 70%, 60%, and 40% PAA. All of the biocomposites were degradable, which resulted in the release of ions/amino acids and a slight pH fluctuation of 6.76 to 7.20. In addition, these biocomposites were biocompatible based on the proliferation of L929 but varied with the degradation rates. These results suggest the potential to control the degradation rates of (DCP + CS)/PAA biocomposites for bone regeneration. POLYM. COMPOS., 39:E122–E131, 2018. © 2016 Society of Plastics Engineers