Fabrication of patterned three-dimensional micron scaled core-sheath architectures for drug patches.

Recent advances in selective integration of micro and nano-scaled features towards material design have paved way to enhance desirable properties or functions of biomaterials. For drug delivery applications these include improved active component encapsulation, controlled drug release and managed interaction with the intended host environment. Electrohydrodynamic (EHD) direct-printing technique is a one-step on demand fiber deposition method which enables precise micron-scaled topographic and structural enhancement during material fabrication. In this study, core-sheath composite fibers comprising polycaprolactone, polyvinyl pyrrolidone and the drug tetracycline hydrochloride were prepared using the coaxial format of EHD direct-printing. Once positioned and aligned; multi-stacked fibers gave rise to patches. Coaxial fiber (diameter range ~13-25 μm) optimization (deposition and integrity) involved parameter-structure (e.g. collector speed, flow rate, working distance and applied voltage) impact analysis. Water contact angle measurements, tensile testing and Fourier transform infrared spectroscopy were used to analyze core-sheath integrated patches. In-vitro drug release studies clearly elude to the impact of core-shell and patterned architectures; demonstrating their viability and the forming method as emerging tools for advanced drug delivery system design and fabrication.