  The combination of cytotoxic therapies and anti-angiogenic agents is emerging
as a most promising strategy in the treatment of malignant tumors. However, the
timing and sequencing of these treatments seem to play essential roles in
achieving a synergic outcome. Using a mathematical modeling approach that is
grounded on available experimental data, we investigate the spatial and
temporal targeting of tumor cells and neovasculature with a nanoscale delivery
system. Our model suggests that the experimental success of the nanoscale
delivery system depends crucially on the trapping of chemotherapeutic agents
within the tumor tissue. The numerical results also indicate that substantial
further improvements in the efficiency of the nanoscale delivery system can be
achieved through an adjustment of the temporal targeting mechanism.
