Figure 2.

Major elements of the intraperitoneal drug delivery. Nanovehicles > 100 nm are rejected (1), but smaller NP can pass from the peritoneal cavity and through the mesothelium into the peritoneal interstitium (2). (1′) represents a delivery to mesotheliomas. (2′) denotes interstitial uptake (by abdominal tumors and ascites). The peritoneal membrane is an idealized partition barrier with heterogeneous sieving characteristics. By diffusion and convection, NP can enter discrete blood (3) and lymph capillaries (4) within the interstitium. Macromolecules and nanovehicles could also diffuse from the blood compartment to the lymphatic (5) or interstitial (6) compartments. Interstitium (peritoneal tissue) is dense network composed of collagenous, glycoprotein, and proteoglycan material. Adapted from Flessner.³⁵