title: Photochemical internalization of tumor-targeted protein toxins.
abstract: Photochemical internalization (PCI) is a method for intracellular delivery of hydrophilic macromolecular drugs with intracellular targets as well as other drugs with limited ability to penetrate cellular membranes. Such drugs enter cells by means of endocytosis and are to a large extent degraded by hydrolytic enzymes in the lysosomes unless they possess a mechanism for cytosolic translocation. PCI is based on photodynamic therapy (PDT) specifically targeting the endosomes and lysosomes of the cells, so that the drugs in these vesicles can escape into the cytosol from where they can reach their targets. The preferential retention of the photosensitizer (PS) in tumor tissue in combination with controlled light delivery makes PCI relatively selective for cancer tissue. The tumor specificity of PCI can be further increased by delivery of drugs that selectively target the tumors. Indeed, this has been shown by PCI delivery of several targeted protein toxins. Targeted protein toxins may be regarded as ideal drugs for PCI delivery, and may represent the clinical future for the PCI technology.
authors: Department of Radiation Biology, Institute for Cancer Research, Norwegian Radium Hospital, Oslo University Hospital, Norway. anette.weyergang@rr-research.no
authors: Anette
authors: A
authors: Weyergang
authors: Pål K
authors: PK
authors: Selbo
authors: Maria E B
authors: ME
authors: Berstad
authors: Monica
authors: M
authors: Bostad
authors: Kristian
authors: K
authors: Berg
mesh_terms: D000970:Antineoplastic Agents / Q000008:administration & dosage* / Q000493:pharmacokinetics / Q000627:therapeutic use; D016503:Drug Delivery Systems; D011992:Endosomes / Q000187:drug effects; D006801:Humans; D000922:Immunotoxins / Q000008:administration & dosage* / Q000493:pharmacokinetics / Q000627:therapeutic use; D008247:Lysosomes / Q000187:drug effects; D046911:Macromolecular Substances / Q000008:administration & dosage / Q000493:pharmacokinetics / Q000627:therapeutic use; D058990:Molecular Targeted Therapy / Q000379:methods*; D009369:Neoplasms / Q000188:drug therapy*; D010778:Photochemotherapy; D017319:Photosensitizing Agents / Q000494:pharmacology
chemical_list: D000970:Antineoplastic Agents; D000922:Immunotoxins; D046911:Macromolecular Substances; D017319:Photosensitizing Agents