Targeted Nanocarriers for Systemic Delivery of IRAK4 Inhibitors to Inflamed Tissues.

Persistent and uncontrolled inflammation is the root cause of various debilitating diseases. Given that interleukin-1 receptor-associated kinase 4 (IRAK4) is a critical modulator of inflammation, inhibition of its activity with selective drug molecules (IRAK4 inhibitors) represents a promising therapeutic strategy for inflammatory disorders. To exploit the full potential of this treatment approach, drug carriers for efficient delivery of IRAK4 inhibitors to inflamed tissues are essential. Herein, the first nanoparticle-based platform for the targeted systemic delivery of a clinically tested IRAK4 inhibitor, PF-06650833, with limited aqueous solubility (57 µg mL -1 ) is presented. The developed nanocarriers increase the intrinsic aqueous dispersibility of this IRAK4 inhibitor by 40 times. A targeting peptide on the surface of nanocarriers significantly enhances their accumulation after intravenous injection in inflamed tissues of mice with induced paw edema and ulcerative colitis when compared to non-targeted counterparts. The delivered IRAK4 inhibitor markedly abates inflammation and dramatically suppresses paw edema, mitigates colitis symptoms, and reduces proinflammatory cytokine levels in the affected tissues. Importantly, repeated injections of IRAK4 inhibitor-loaded nanocarriers have no acute toxic effect on major organs of mice. Therefore, the developed nanocarriers have the potential to significantly improve the therapeutic efficacy of IRAK4 inhibitors for different inflammatory diseases.