Related Experiment Videos
Multicellular membranes as an in vitro model for extravascular diffusion in tumours
D S Cowan1, K O Hicks, W R Wilson
1Pathology Department, University of Auckland, New Zealand.
The British Journal of Cancer. Supplement
|July 1, 1996
Summary
Efficient extravascular diffusion is key for drugs targeting hypoxic tumors. This study shows simple nitroimidazoles diffuse well, but DNA-intercalating agents face challenges, impacting their tumor penetration.
Area of Science:
- Pharmacology
- Tumor Microenvironment
- Drug Delivery
Background:
- Efficient extravascular diffusion is crucial for drugs targeting hypoxic tumor cells.
- Hypoxic cell radiosensitisers, bioreductive drugs, and markers require unimpeded movement through tumor tissue.
Purpose of the Study:
- To investigate the extravascular diffusion of various nitroimidazoles using a novel multicellular membrane (MM) model.
- To compare the diffusion characteristics of neutral, basic, and DNA-intercalating nitroimidazoles in a tumor-like environment.
Main Methods:
- Utilized multicellular membranes (MMs) as an in vitro model for the tumor's extravascular compartment.
- Employed mathematical modeling to determine diffusion coefficients (DMM) from flux kinetics.
- Investigated diffusion of misonidazole, pimonidazole, NLA-1, and 2-NLP-3.
Main Results:
- Misonidazole diffusion was concentration-independent and significantly slower in MMs (DMM = 5.5 x 10(-7) cm2 s-1) compared to culture medium.
- Hypoxia minimally affected misonidazole diffusion over 200 microns.
- DNA-intercalating nitroimidazoles (2-NLP-3, NLA-1) exhibited lower diffusion coefficients than simple nitroimidazoles, with NLA-1 showing more severe compromise.
Conclusions:
- Multicellular membranes effectively model extravascular drug diffusion.
- Simple nitroimidazoles demonstrate adequate diffusion, while DNA-intercalating agents face diffusion limitations.
- The study highlights potential challenges in delivering DNA-intercalating nitroimidazoles to deep tumor regions.