Hypoxia is a condition occurring in several disorders resulting in lower levels (1-5%) of molecular oxygen (O2) compared to the normoxic conditions of healthy physiological environment, where the O2 tension is typically between 10 and 21%. This status is mainly induced by the poor vascularization or impaired blood flow characterizing potentially fatal illnesses like solid tumors, microbial and fungal infections and biofilms, cerebral and myocardial ischemia, etc. The harshness of hypoxia resides in its ability to annihilate the efficacy of current drug-based therapies as it boosts drug resistance and to reduce the effects of radiotherapy and photodynamic therapy (PDT) as well.