Application Of Polyhydroxyalkanoates 3D Porous Microsphere Scaffold As Cell Carrier In Tissue Engineering

In this study, we generated a novel biopolymer porous microsphere scaffold as cell carrier using polyhydroxyalkanoates (PHAs), and evaluated its biocompatibility. Porous microsphere scaffolds were prepared using a typical water-in-oil-in-water (W1/O/W2) double emulsion method with ammonium bicarbonate in the inner (W1) droplets as a gas foaming agent. Poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBHHx), which is block polymer of HB and HHx in PHAs family with a good biocompatibility, was chosen in this study. Seven factors influencing the preparation of the scafold, including organic solvent, ammonium bicarbonate content as inner water phase (W1) , PVA content as outer water phase (W2), ratio of PHBHHx/organic solvent as oil phase, ratio of W1/O, homogenizer speed of primary emulsion and temperature, were optmized in this study. Finally, PHBHHx porous microsphere scaffolds with a diameter of 415.31μm,mean diameters of surface pores of 22.71μm and mean water uptake ratio of 31.65 were generated. L929 and NIH/3T3 cells were seeded into PHBHHx porous microsphere scaffolds described above to study its biocompatibility. Using laser scanning confocal microscope and scanning electron microscope, we observed that cells adhered onto surface of microsphere scaffolds after 24 h of seeding, and some cells moved into interior of scaffold after 96 h. The number of cells increased in the process of culture. The morphology of cells on surface was different from those inside. It is concluded that PHBHHx porous microsphere scaffold is a novel cell carrier with good biocompatibilities in tissue engineering.