Au-NPs Functionalizaed Microneedles as Intelligent Components for Portable Devices

Nowadays the direct healthcare cost represent an enormous part of the government welfare system and it is still increasing worldwide. The development of minimally invasive devices could unload the pressure of the welfare system and at the same time could support patients in-home therapy avoiding hospitalization and all the emotional commitment related to it (anxiety, stress, panic attack, fear). If we add that it is estimated that 5.4 million cases of carcinoma are diagnosed annually in the United States among 3.3 million people (sometimes more than 1 nonmelanoma skin cancer per person), with a rate increased up to 77% in the last years, it appears still more evident the urgency to design innovative and portable systems. Despite all the conventional, and debilitating radiotherapies/chemotherapy, photo-thermal therapy (PTT) is arising as a promising solution for cancer management, predominantly when mediated by gold nanoparticles (Au NPs) for their intrinsic ability to convert a monochromatic (resonant) light into thermal energy [2]–[4]. However, the weakness of current therapy by light is that light cannot penetrate the skin deeply because of the skin properties (a complex heterogeneous medium with various optical characteristics) and consequent tissue's absorption, reflection, and refraction. Creating a light-through channel from outside the skin to the cells to target could be an excellent tool for realizing minimally invasive and in-situ PTT. Here we discuss about the fabrication of advanced functionalized microneedles (MNs) as micro photonic structures. Gold nanoparticles (Au NPs) are selected as nanofiller components for transdermal drug delivery properties because of their intrinsic ability to convert a monochromatic (resonant) light into thermal energy (photo-thermal effect). We propose a nano in micro strategy by embedding (Au NPs) in a microarray of polymeric microneedles. The various methods proposed and used for micro-needle fabrication usually require long-lasting procedures, high cost, and restriction in drug contents. We describe a new electro-drawing approach for the mold-free and contact-free fabrication of conic microstructures. The functionalized microstructures could be employed to locally deliver Au NPs with high absorption and elevate photo-thermal efficiency in the skin layer. Moreover the same functionalization could be used as a bio sensing element for a portable device. The proof of concept of the innovative MNs proposed would represent a useful strategy for realizing innovative patient-tailored therapy with particular attention to long-term space exploration missions.