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

Abstract

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

3D bioactive composite scaffolds for bone tissue engineering

“…Dicalcium phosphate (DCP) has been used much less frequently than HA within BTE, due to weak, brittle mechanical properties and a high in vivo resorption rate [115] . Although DCP/synthetic polymer composites have been produced resulting in improved mechanical properties, success has been limited in comparison to HA and tricalcium phosphate based scaffolds with degradation rates difficult to control [130] , [131] , [132] .…”

“…Unfortunately, infiltration of microvessels often lacks depth of penetration, limiting the size of viable bone construct that can be implanted [366] , [367] . Achieving precise control over scaffold degradation [132] , [251] , [440] . If a scaffold degrades too quickly, mechanical failure can occur.…”

“…Achieving precise control over scaffold degradation [132] , [251] , [440] . If a scaffold degrades too quickly, mechanical failure can occur.…”

Preparation, Characterization and In Vitro Biological Evaluation of a Novel Pearl Powder/Poly-Amino Acid Composite as a Potential Substitute for Bone Repair and Reconstruction

“…The degradation of the P/PAA composites can be divided into three parts: the dissolution of small molecules and oligomers in the composites, the hydrolysis of the PAA and the dissolution of pearl powder. The hydrolysis of the PAA is mainly due to the hydrolysis of amide bond (–CO–NH–), and the slightly acidic environment could accelerate the hydrolysis of PAA [35,36]. The formation of apatite on the surface of the composites might be the one reason for the reduced degradation.…”

Simonkolleite Coating on Poly(Amino Acids) to Improve Osteogenesis and Suppress Osteoclast Formation in Vitro

“…In addition, as reported, simonkolleite can be precipitated from zinc chloride solution [18,19,20], so that immersing the substrate materials with basic groups into a zinc chloride solution to allow the simonkolleite to precipitate on a solid surface might be a simple and effective way to prepare simonkolleite coating. Poly(amino acids) (PAA), fabricated by an in-situ melting method, are currently used as an organic phase in composites for bone reconstruction [21], exhibiting not only suitable mechanical properties but also tailorable degradation rates for bone regeneration [22]. Though it has excellent properties in terms of being a non-toxic, low-cost, simple synthetic process with easy processing [23], it is biologically inert, which may induce fibrous encapsulation, hindering the osteogenesis process [24].…”