Syntheses and Evaluation of Copolymer 6-Aminohexanoic Acid and 4R-Hydroxy-L-Proline for Bone Repair

Abstract

A novel synthetic copolymer (PAA) for bone repair was prepared by melt condensation polymerization with 6-aminohexanoic acid (He) and 4R-hydroxy-L-proline (Hyp). The structure and thermal property were characterized by infrared spectrometer (IR), nuclear magnetic resonance (H1NMR) and differential scanning calorimeter (DSC). The results indicated that the PAA had amide linkages in their polymer chains. The Tg of PAA was 57.56°C and significantly higher than that of nylon6, 50.46°C. Meanwhile, the intrinsic viscosity and mechanical properties were investigated at different He/Hyp ratios. It revealed that appropriate introduction of Hyp group could control the degree of polycondensation and adjusted mechanical properties of PAA obviously close to natural bone. The prepared polymers had about 2.12~18.21 % weight loss after 8-week soaking in PBS, showed degradable properties which was essentials to new bone growth. The copolymer of He and Hyp with ratios of 90/10 had 6.57 % weight loss and maintained the yield compressive strengths with about 67.51 MPa after 8 weeks, which exhibited a compatible mechanical properties and degradation speed for bone repair.

Preparation and properties of BSA-loaded microspheres based on multi-(amino acid) copolymer for protein delivery

“…MAC had two crystalline peaks at 2θ=19.9° and 2θ=23.5°, which agreed with previous studies. 14,15 The intensity of the two peaks in the MAC microspheres and BSA-loaded microspheres decreased significantly compared to the MAC raw material. The results suggest that crystallinity of the microspheres decreased throughout the double-emulsion solvent extraction process after the formation of microspheres because the solvent evaporated rapidly in a short time, and the copolymer crystallized and had loose structure in the inner water phase.…”

The Importance of 6-Aminohexanoic Acid as a Hydrophobic, Flexible Structural Element

“…Copolyamino acids based on 6-aminohexanoic acid and protein amino acid structures have been investigated as potential biodegradable polymers [93,94] that can be used for biomedical purposes and as biodegradable packing materials. For example, copolymers of 6-aminohexanoic acid and hydroxyproline have been investigated as potential bone repair materials [95].…”