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Cancer Therapy

Photodynamic Therapy

Tumor Targeted Photosensitizers

Long Wavelength Photosensitizers

Imaging & Therapy

PET / Fluorescence

Fluorescence

Nanotechnology

Nanotechnology

 

Related Publications

Target-Specific Photosensitizers for PET / Fluorescence Imaging
with an Option of PDT

The avß3 integrin receptor plays an important role in human metastasis and tumor-induced angiogenesis. Cyclic Arg-Gly-Asp (cRGD) peptide represents a selective avß3 integrin ligand that has been extensively used for research, therapy, and diagnosis of neoangiogenesis. For developing photosensitizers (PS) with enhanced photodynamic therapy (PDT) efficacy, Photolitec has synthesized a series of bifunctional agents in which the PS, a chlorophyll-based photosensitizer, was conjugated to cRGD and the related analogues.

The cell uptake and in vitro PDT efficacy of these PL-agents were studied in avß3 integrin over expressing U87 and 4T1 cell lines, whereas the in vivo PDT efficacy and fluorescence-imaging potential of the conjugates were compared with the corresponding nonconjugated photosensitizer in 4T1 tumors. Compared to HPPH, the HPPH_cRGD conjugate in which the arginine and aspartic acid moieties were available for binding to two subunits of avß3 integrin showed faster clearance, enhanced tumor imaging and enhanced PDT efficacy at 24 h postinjection. Molecular modeling studies also confirmed that the presence of the HPPH moiety in HPPH_cRGD conjugate does not interfere with specific recognition of cRGD by avß3 integrin. Compared to U87 and 4T1 cells, the HPPH_cRGD showed significantly low photosensitizing efficacy in A431 (avß3 negative) tumor cells, suggesting possible target specificity of the conjugate.


Photolitec ventured into a new approach to optimize PDT and successfully develop agents which are capable of targeting certain tumors and demonstrated that these agents can function as an imaging and/or therapeutic agent. These products have shown significant target specificity for brain and breast cancers, known for over-expression of avß3 integrin.

 

Related Publications

Comparative Positron-Emission Tomography (PET) Imaging and Phototherapeutic Potential of 124I- Labeled Methyl- 3-(1--iodobenzyloxyethyl)pyropheophorbide-a vs the Corresponding Glucose and Galactose Conjugates
Suresh K. Pandey, Munawwar Sajjad, Yihui Chen, Xiang Zheng, Rutao Yao, Joseph R. Missert, Carrie Batt, Hani A. Nabi, Allan R. Oseroff, and Ravindra K. Pandey
J. Med. Chem. 2009, 52, 445–455
View Abstract - View Publication

Conjugation of cRGD Peptide to Chlorophyll a Based Photosensitizer (HPPH) Alters Its Pharmacokinetics with Enhanced Tumor-Imaging and Photosensitizing (PDT) Efficacy
Avinash Srivatsan, Manivannan Ethirajan, Suresh K. Pandey, Shipra Dubey, Xiang Zheng, Ting-Hsiu Liu, Masayuki Shibata, Joseph Missert, Janet Morgan, and Ravindra K. Pandey
Molecular Pharmaceutics, 2011, 8, 1186–1197
View Abstract - View Publication