Self-assembled hyaluronic acid nanoparticles for controlled release of agrochemicals and diosgenin
Sprache des Titels:
Commercial sodium hyaluronate (HA) and synthetic hydrazide-modified HA were functionalized withdiosgenin and two agrochemicals (brassinosteroids DI31 and S7) with degree of substitution rangingfrom 5.6 to 13.1%. The HA-steroid conjugates were studied with FTIR,1H NMR and differential scanningcalorimetry. Dynamic light scattering revealed self-assembly of the HA-steroid conjugates into stablenegatively charged nanoparticles of around 159 nm?441 nm in water, which after drying appeared as140 nm?370 nm spherically shaped nanoparticles according to transmission electron microscopy. Thesenanoparticles exhibited almost constant release rates of steroids for the first 8 h, demonstrating sus-tained steroids delivery for 72 h in acidic medium. The nanoparticles formed from HA-steroid conjugateswere not cytotoxic to human microvascular endothelial cells (HMVEC), while the HA- brassinosteroidnanoparticles showed in vitro agrochemical activity that was superior to the activity observed for theparent brassinosteroids DI31 and S7 at 10?5to 10?7mg mL?1.