Physical properties
Chen et al. (2) suggest that the changing PHA compositions allow favorable mechanical properties, biocompatibility, and degradation times within desirable time frames under specific physiological conditions (Table 1). From this table, we find that the melting temperature (Tm) and glass-transition temperature (Tg) of PHBHHx are dependent on the content of 3-hydroxyhexanoate (HHx), i.e., the higher the proportion of HHx, the lower the Tm and Tg values. Crystallinity of PHBHHx also decreases with increase in the content of HHx. In the composite system of PHB/PHBHHx, similar findings are observed. Chen et al. (2) also revealed that PHB/PHBHHx blended at a ratio of 1:1 has the maximum surface free energy, a key parameter affecting adhesion, distribution, and differentiation of seeded cells (2,19).