Methods: In this study, for making gelatin and hydroxyapatite microspheres, the method of emulsion (water in oil) was used. In this experiment, the aqueous solution was dispersed by mechanical stirrer, homogenizer, and ultrasonic homogenizer. Aqueous solution including polymer and ceramic was added dropwise into oil and was stirred. After 30 min, the solution temperature was lowered to 10°C with constant stirring. Then chilled acetone was added to stirring solution to solidify microspheres. After that, glutaraldehyde was added to the solution as crass linking agent. The microspheres were washed several times to remove residual oil. Their characteristics were followed by optical microscopy, scanning electron microscopy (SEM), and Fourier transform infrared spectroscopy (FTIR).
Results: The results showed that the use of ultrasonic homogenizer fabricated smaller and more uniform particles than the use of homogenizer, but the use of mechanical stirrer did not produce any microspheres. The FTIR result showed that several times washing microspheres removed residual oil and glutaraldehyde from microspheres.
Conclusions: This study showed that dispersion of the aqueous phase by different tools effects the size of particles. Since these particles are used as cell carrier, the size and distribution of microspheres is important. The methods which make smaller and more uniform microspheres are better than those for cell culture and cell carrier.