Preformed Biodegradable Zwitterionic Nanoparticles as Tunable Excipients for the Formulation of Therapeutics Directly at the Point of Care

Polyester-based nanoparticles (NPs) are among the most adopted drug delivery systems developed so far. This is mainly due to their ability to increase the bioavailability of the loaded therapeutics, to prevent the adverse effects often associated with their use, and to eliminate the toxic excipients necessary to formulate them. In addition, these NPs are biodegradable under physiological conditions thus avoiding the polymer accumulation in the body. However, the complexity in the formulation and storage hampers the cost-effective use of these formulations reducing their availability among the patient population. In addition, the manifold drugs available on the market, characterized by different chemical structures and charges, impose the continuous optimization of different delivery systems for their efficient formulation. Therefore, tunable NPs able to encapsulate different drugs with high loading efficiencies and to modulate their release after administration are urgently needed. In this work, a method to formulate different drugs directly at the point of care using only a syringe and starting from preformed NPs has been developed. Highly tunable zwitterionic NPs have been synthesized via the combination of ring opening polymerization and reversible addition-fragmentation chain transfer emulsion polymerization and then used to load paclitaxel, doxorubicin, or ibuprofen with high efficiency. The controlled release of such therapeutics has been achieved by tuning the characteristics of the NPs, in particular by the addition of charged groups.