Fe3O4/Polycaprolactone Microneedles with Controlled Drug Delivery and Magnetic Hyperthermia

In this study, we have developed biodegradable Fe3O4/polycaprolactone (Fe3O4/PCL) microneedles with controlled drug delivery and magnetic hyperthermia, which consist of biodegradable PCL and the encapsulated Fe3O4 nanoparticles, drugs and low-melting-point monomer (trimethylene carbonate, TMC). The structure, mechanical strength, magnetic heating ability and drug release behavior of the Fe3O4/PCL microneedles were characterized. Each microneedle patch shows well-structured microneedle arrays comprised of 100 (10 × 10) pyramidal needles with a tip-to-tip distance of 500 μm, and the microneedles have enough mechanical strength to penetrate skin. Interestingly, the Fe3O4/PCL microneedles could generate heat to increase the temperature under an alternating magnetic field. Also, the Fe3O4/PCL microneedles exhibit the temperature-controlled drug release behavior through adjusting the encapsulated TMC amount. Hence, the developed Fe3O4/PCL microneedles show potential synergistic chemotherapy and magnetic hyperthermia in skin cancer treatment.