A Rationally Designed Micellar Nanocarrier for the Delivery of Hydrophilic Methotrexate in Psoriasis Treatment.

Methotrexate (MTX) is broadly applied in the clinic for the treatments of cancers and autoimmune diseases. Targeted delivery of MTX is attractive to improve its efficacy and reduce off-target toxicity. However, MTX encapsulation in nanoparticle is challenging due to its high water solubility. We rationally designed a well-defined telodendrimer (TD) nanocarrier based on MTX structure to sequester it in nanoparticles. Riboflavin (Rf) and positive charges groups were precisely conjugated on TD to form multivalent hydrogen bonds, π-π stacking and electrostatic interactions with MTX. A reverse micelle approach was developed to preset MTX and TD interactions in the core of micelles, which ensures the effective MTX loading upon dispersion into aqueous solution. As results, MTX loading capacity reaches over 20% (w/w) in the optimized nanocarrier with the particle size of 20-30 nm. The nanoformulations sustain the release of MTX in a controlled manner and exhibit excellent hemocompatibility. The cellular uptake of MTX was significantly improved by the nanoformulations. The potency of MTX nanoformulations is comparable to the free MTX in cytotoxicity. A psoriasis-like skin inflammation model was induced in mouse by imiquimod (IMQ) stimulation. MTX nanoformulations improved the psoriasis targeting and exhibited a superior long-lasting efficacy in reducing skin inflammation compared with the free MTX in psoriasis treatment.