They found that the water contact angle on the PHBHHx/SF was smaller than that on the pure PHBHHx scaffold, and the number of cells attached to the surface of PHBHHx/SF films was larger than on the control films, indicating an improvement in hydrophilicity and biocompatibility. Additionally, PHA family members may be blended with each other. Scaffolds made from PHBHHx and PHB at a ratio of 1:1 have a higher surface free energy and are more ffective for chondrocyte adhesion than scaffolds made of PHBHHx alone (19). In another study, adipose-derived mesenchymal stem cells inoculated on PHB/PHBHHxscaffolds and implanted into animals were found to generate cartilage-like tissues 14 days after implantation