Delivery of Multipurpose Prevention Drug Combinations from Electrospun Nanofibers Using Composite Microarchitectures

Background: Electrospun drug-eluting fabrics have enormous potential for the delivery of physicochemically diverse drugs in combination by controlling the underlying material chemistry and fabric microarchitecture. However, the rationale for formulating drugs at high drug loading in the same or separate fibers is unknown but has important implications for product development and clinical applications.

Methods: Using a production-scale free-surface electrospinning instrument, we produced electrospun nanofibers with different microscale geometries for the co-delivery of tenofovir (TFV) and levonorgestrel (LNG) - two lead drug candidates for multipurpose prevention of HIV acquisition and unintended pregnancy. We investigated the in vitro drug release of TFV and LNG combinations from composites that deliver the two drugs from the same fiber (combined fibers) or from separate fibers in a stacked or interwoven architecture. For stacked composites, we also examined the role that fabric thickness has on drug-release kinetics. We also measured the cytotoxicity and antiviral activity of the drugs delivered alone and in combination.

Results: Herein, we report on the solution and processing parameters for the free-surface electrospinning of medical fabrics with controlled microarchitecture and high drug loading (up to 20 wt%). We observed that in vitro release of the highly water-soluble TFV, but not the water-insoluble LNG, was affected by composite microarchitecture, fabric thickness, and drug content. Finally, we showed that the drug-loaded nanofibers are noncytotoxic and that the antiviral activity of TFV is preserved through the electrospinning process and when combined with LNG.

Conclusion: Electrospun fabrics with high drug loading create multicomponent systems that benefit from the independent control of the nanofibrous microarchitecture. Our findings are significant because they will inform the design and production of composite electrospun fabrics for the co-delivery of physicochemically diverse drugs that may be useful for multipurpose prevention.