Background: Collagenase and hyaluronidase are enzymes which degrade the extracellular matrix and increase the uptake and improve the distribution of therapeutic macromolecules in tumours. The purpose of the present work was to investigate whether collagenase or hyaluronidase had any effects on transient perfusion and/or changes in vascular areas.
Materials and methods: The effects were studied in human osteosarcomas in BALB/c nu/nu mice growing orthotopically around and infiltrating the femurs, and in dorsal skinfold chambers using confocal laser scanning microscopy.
Results: Both collagenase and hyaluronidase reduced the number of vessels that closed, but only collagenase increased the number of vessels which opened up, i.e. both enzymes improved the perfusion but collagenase to a greater extent than hyaluronidase.
Conclusion: Destroying the structural protein network seems to be more efficient than degrading the gel of hyaluronan with respect to increase perfusion.