A pH-stable, mucin based nanoparticle system for the co-delivery of hydrophobic and hydrophilic drugs

Biopolymer-based drug carriers are commonly used for the development of safe delivery systems. However, biopolymer-based systems are often highly sensitive to the acidic pH levels in the stomach and release most of their cargo before they have reached their point of destination. Such premature drug release combined with the resulting high dose requirements is not cost-efficient and comes with the risk of unwanted side effects on non-target tissues/organs. This problem can be mitigated by the mucin-based drug carriers developed here, which exhibit good stability at acidic pH levels as proven by dynamic light scattering and enzymatic degradation tests with pepsin. In addition, the mucin-based particles can deliver hydrophobic and hydrophilic drugs simultaneously, which is demonstrated both with experiments performed under in vitro sink conditions and with drug transport tests involving eukaryotic cells as targets. As photo-induced cross-links covalently stabilize those particles, they can release their payload over time in a sustained manner. The drug carrier system introduced here combines good stability with high drug encapsulation efficiency and very good biocompatibility and thus may be valuable for a broad spectrum of applications in biological settings.