Biocompatibility Of Poly(3-hydroxybutyrate-co-4-hydroxybutyrate-co-3-hydroxyhexanoate) And Poly(3-hydroxybutyrate-co-3-hydroxyvalerate-co-3-hydroxyhexanoate)

As new members of polyhydroxyalkanoate (PHA) family, poly (3-hydroxybutyr- ate-co-4-hydroxybutyrate-co-3-hydroxyhexanoate) (P(3HB- 4HB- 3HHx)) was prod- uced by recombinant Aeromonas hydrophila 4AK4 harboring phaPCJ genes and poly (3-hydroxybutyrate-co-3-hydroxyvalerate-co-3-hydroxyhenanote) (PHBVHHx) was produced by recombinant Aeromonas hydrophila 4AK4 harboring phaAB genes. They were used for the first time to test their biocompatibility. It was shown that P(3HB- 4HB-3HHx) and PHBVHHx had higher hydrophobicity, surface energy and rougher surface than the well-studied polyers poly(l-lactic acid) (PLA) and poly (3-hydroxyb- utyrate-co-3-hydroxyhexanoate) (PHBHHx). Human mesenchymal stem cells (MSCs) attached better on P(3HB-4HB-3HHx) film and PHBVHHx film than on tissue cul- ture plates (TCPs), PLA film and PHBHHx film. MSCs proliferation on P(3HB-4HB -3HHx) film was 126% higher than that on tissue culture plates (TCPs), 84% higher than that on PHBHHx film and 312% higher than that on PLA film (p<0.01). And MSCs proliferation on PHBVHHx film was 115% higher than that on tissue culture plates (TCPs), 66% higher than that on PHBHHx film and 263% higher than that on PLA film (p<0.01). P(3HB-4HB-3HHx) and PHBVHHx also supported osteogenic differentiation of MSCs. Previous studies found that all PHA materials tested were ei- ther less than, or equal to TCPs for supporting cell growth. Among all PHA materials tested, P(3HB-4HB-3HHx) and PHBVHHx were the only two PHA materials to sig- nificantly promote cell proliferation compared with TCPs. These data demonstrated that P(3HB-4HB-3HHx) and PHBVHHx could be promising biomaterials for bone ti- ssue engineering.