Electrosprayed tricalcium phosphate spherical microcups and antibiotic drug delivery

Here we prepared tricalcium phosphate (TCP) spherical cups of a few micrometers in size (average = 2.74 μm) by applying the electrospraying method. The sol–gel precursor containing calcium and phosphate (Ca/P = 1.5) was mixed with Polyvinylpyrrolidone in ethanol at varying concentrations, and then sprayed under a controlled electrostatic field. The jets from the sol–gel solution changed from a complete fibrous mesh into a formation of microbeads connected with fibers and then further into a complete formation of microbeads as the solution viscosity became decreased. After the thermal treatment (800–1100 °C), individual microbeads remained, to form the shape of a spherical cup and retained the phase of β-TCP. The drug delivery potential of the TCP micro-cups, as assessed by using an antibiotic drug ampicillin, demonstrated a dose dependent loading capacity and almost a linear release profile over a day.