Mohamed et al. developed nanoMIL-89 for targeted delivery of sildenafil, a vasodilator belonging to the phosphodiesterase type 5 (PDE5) inhibitor class, used in the treatment of pulmonary arterial hypertension (PAH), which is one of the most frequent complications in COPD patients [108]. Here, PDE5A is linked to pulmonary arterial hypertension.