Abstract

Infantile hemangioma is a tumor of the microvasculature composed predominantly of proliferating endothelial cells. Pingyangmycin (bleomycin A5), a water-soluble glycopeptide produced by Streptomyces pingyangensisn, has been used as a sclerosing agent for the treatment of hemangioma. However, its utility is limited by adverse side effects, including significant pain, swelling, pulmonary fibrosis and life-threatening dyspnea. Therefore, further improvement of the efficacy and safety of pingyangmycin sclerotherapy is essential. Here, we proposed to use liposomes as a carrier that can modify pharmacological properties of encapsulated drugs and thereby reduce tissue toxicity. Taking advantage of the finding that hemangioma-derived endothelial cells constitutively overexpress vascular endothelial growth factor receptor 2 (VEGFR2), an endothelial cell-targeting delivery system was designed by coupling liposomes with vascular endothelial growth factor (VEGF) ligand. Due to the interaction between VEGF and VEGFR2, the liposomal formulation of pingyangmycin would be delivered to desired endothelial compartments of hemangioma lesions. In conclusion, we believe that the VEGF-mediated targeting delivery of liposomal pingyangmycin would improve therapeutic efficacy, minimize the related complications, and represent a promising treatment option for hemangioma.

Key words: Pingyangmycin, sclerotherapy, hemangioma, endothelial growth factor (VEGF).