Anti-cancer agents that are administered intravenously must pass through the wall of tumor vessels and the interstitial matrix to have access to tumor cells. In normal tissues the movement of macromolecules is facilitated by bulk flow, however, in the center of tumors because of the equilibrium in hydrostatic pressure between the microvascular and interstitial space convection is less significant (1). Thus diffusion becomes the main mode of interstitial transport in the center of tumors (2). The diffusion and penetration through the tumor interstitium of anti-cancer agents will depend on their physicochemical properties (size, charge, shape) and the composition and characteristics of the interstitial matrix. It is essential to identify the constituents of the tumor interstitial matrix that will hinder the diffusion and penetration of large anti-cancer agents (e.g. gene vectors, proteins) and thus limit their therapeutic efficacy.
展开▼
