PLGA thin films were prepared onto implantable devices by the electrospray and pressurized spray method. Thin films with structural gradients were obtained by controlling four parameters consisting of solution concentration, applied voltage, air pressure, and deposition time. The surface morphologies of the deposited films were observed using scanning electron microscopy (SEM). The image analysis revealed the control factors on the preparation of PLGA thin films. The beaded structure is easily formed with a decrease in polymer concentration while the fibrous structure is easily formed with an increase in polymer concentration. With the increase in applied voltage, the surface morphologies changed continuously from a small amount of fibrous shape to a large fibrous one: a small amount of fibrous shape at 10 kV, more fibers with non-uniform diameter at 20 kV, and most fibers with uniform diameter at 30 kV. Low air pressure (0.1 MPa) corresponded to round particles while high air pressure (0.3 MPa) corresponded to flat particles. The change in thickness from 5.34 to 10.1 μm was a result of deposition time increasing from 5 to 10 s. From our above work, films of the bead or fiber structures can be obtained by changing electrical parameters to improve the biocompatibility of the film.
展开▼
