Y.-W. Wang, Q. Wu, and G.-Q. Chen
Department of Biological Science and Bioengineering, Tsinghua University, Beijing, China
Keywords: PHBHHx, biodegradability, biocompatibility, mechanical property
Random copolyesters consisting of 3-hydroxybutyrate and 3-hydroxyhexanoate (PHBHHx) is a member of PHA family. Previous studies have showed that PHBHHx had good biocompatibility for osteoblast [1] and owned good biodegradability in phosphate buffer saline (PBS) containing lipase [2]. PHBHHx varying different content of hydroxyhexanoate (HHx) all showed good biocompatibility for osteoblast and fibroblast though cell responses had a little variance corresponding to HHx content due to different surface properties [3].
To meet the need of different tissues in the body, hydroxyapatite (HAP) and gelatin were incorporated into PHBHHx to vary its mechanical properties and biodegradabilities respectively. Phase separation was observed during HAP incorporation, which resulted in decreases of compressive modulus of PHBHHx scaffold. When increasing the evaporation temperature of chloroform solvent, phase separation was reduced which made increases of compressive modulus of PHBHHx scaffold. Gelatin was found miscible to PHBHHx. After blending, degradation was accelerated which may be contributed from its higher porosity and lower crystallinity besides fast degradation of gelatin.
All these indicated that PHBHHx may be developed to a series of biomaterials which could meet different requirement on degradabilities, mechanical properties and biocompatibilities.
[1] Wang et al., 2004. Biomaterials 25, 669-75.
[2] Wang, et al. Polymer Degradation and Stability (in press).
[3] Wang et al., Biomaterials (in press).
[4] Wang et al., Biomaterials (in press).
