Figure 7.

Formulation and mechanism of action of porphyrin metallacages nanoparticles containing hyaluronidase against hypoxic tumors reported by Jiao et al. [154]. The nanocarrier was prepared by combining a porphyrin metallacage, in which cavities are concentrated with triplet molecular oxygen, and the enzyme hyaluronidase, coated with 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-(methoxy-polyethylene glycol)-2000 (DSPE-PEG₂₀₀₀). Hyaluronidase allowed the degradation of the extracellular matrix, resulting in greater formulation accumulation inside tumor cells. Molecular oxygen release from metallacages combined with hypoxia relieved by angiogenesis suppresses the expression of hypoxia-inducible factor-1α (HIF-1α) and consequent tumor growth inhibition. Irradiation with a laser emitting at 660 nm activates porphyrin, which, once activated, produces singlet oxygen, culminating in cell death.