An increase in hyaluronan (HA) synthesis, cellular uptake, and metabolism occurs during the remodeling of tissue microenvironments following injury and during disease processes such as cancer. We hypothesized that multimodality HA-based probes selectively target and detectably accumulate at sites of high HA metabolism, thus providing a flexible imaging strategy for monitoring disease and repair processes. Kinetic analyses confirmed favorable available serum levels of the probe following intravenous (i.v.) or subcutaneous (s.c.) injection. Nuclear (technetium-HA, Tc-99m-HA, and iodine-HA, I-125-HA), optical (fluorescent Texas Red-HA, TR-HA), and magnetic resonance (gadolinium-HA, Gd-HA) probes imaged liver (Tc-99m-HA), breast cancer. cells/xenografts (TR-HA, Gd-HA), and vascular injury (I-125-HA, TR-HA). Targeting of HA probes to these sites. appeared to result from selective HA receptor-dependent localization. Our results suggest that HA-based probes, which do not require, polysaccharide backbone modification to achieve favorable half-life and distribution, can detect elevated HA metabolism in homeostatic, injured, and diseased tissues.
2012. Vol. 13, no 1, 12-22 p.