Degradable biocomposite of nano calcium- deficient hydroxyapatite-multi(amino acid) copolymer

Abstract

Background and methods:A nano calcium-deficient hydroxyapatite (n-CDHA)-multi(amino acid) copolymer (MAC) composite bone substitute biomaterial was prepared using an in situ polymerization method. The composition, structure, and compressive strength of the composite was characterized, and the in vitro degradability in phosphate-buffered solution and preliminary cell responses to the composite were investigated. Results: The composite comprised n-CDHA and an amide linkage copolymer. The compressive strength of the composite was in the range of 88-129 MPa, varying with the amount of n-CDHA in the MAC (ranging from 10 wt% to 50 wt%). Weight loss from the composite increased (from 32.2 wt% to 44.3 wt%) with increasing n-CDHA content (from 10 wt% to 40 wt%) in the MAC after the composite was soaked in phosphate-buffered solution for 12 weeks. The pH of the soaking medium varied from 6.9 to 7.5. MG-63 cells with an osteogenic phenotype were well adhered and spread on the composite surface. Viability and differentiation increased with time, indicating that the composite had no negative effects on MG-63 cells. Conclusion:The n-CDHA-MAC composite had good cytocompatibility and has potential to be used as a bone substitute.

Effects of mechanical loading on the degradability and mechanical properties of the nanocalcium-deficient hydroxyapatite–multi(amino acid) copolymer composite membrane tube for guided bone regeneration

“…In previous research, 9 it was found that the compressive strength of this n-CDHA-MAC composite was about 127 MPa, which is similar to that of natural cortical bones of humans. 16 In our study, the n-CDHA-MAC composites were processed into a tubular shape, thus preserving the continuity of the diaphysis for the repair of large diaphyseal bone defects.…”

“…9,19 The femur length and thickness were measured in six fresh femurs of 2-year-old goats (of either sex and either side of femur) to make the 30 mm-segment bone defects and measure the diameter of proximal and distal ends. Femur length from the intertrochanteric fossa to the midpoint of the medial and lateral condyle were measured as the standard length.…”

“…[6][7][8] Recently, a nanocalcium-deficient hydroxyapatitemulti(amino acid) copolymer (n-CDHA-MAC) composite was developed. 9 This n-CDHA-MAC is a novel degradable composite with good mechanical strength and suitable degradation rate, in which compressive strength is close to natural human cortical bone. 9 Therefore, the membrane tube of the n-CDHA-MAC has great potential to keep enough tube volume in GBR.…”

“…9 This n-CDHA-MAC is a novel degradable composite with good mechanical strength and suitable degradation rate, in which compressive strength is close to natural human cortical bone. 9 Therefore, the membrane tube of the n-CDHA-MAC has great potential to keep enough tube volume in GBR. Biomaterials under mechanical load showed a more rapid degradation rate compared with biomaterials under static conditions.…”

“…Consequently, it is necessary to investigate the degradation behavior of the n-CDHA-MAC membrane tube under mechanical loading. 9 Goats' limb bones are the most similar ones to humans', and this study is based on large segmental defects of goats.…”