Biological Barriers to Protein Delivery

I. Cellular Barriers.- 1 The Paracellular Pathway: A Small Version of the Kidney Nephron.- 2 Ectopeptidases.- 3 Endosomal and Lysosomal Hydrolases.- 4 Protein Uptake and Cytoplasmic Access in Animal Cells.- II. Epithelial Barriers.- 5 Transepithelial Transport of Proteins by Intestinal Epithelial Cells.- 6 Intraoral Peptide Absorption.- 7 Macromolecular Transport across Nasal and Respiratory Epithelia.- 8 Dermal Absorption of Peptides and Proteins.- 9 Rectal and Vaginal Absorption of Peptides and Proteins.- III. Vascular Barriers.- 10 Vascular Endothelial Barrier and Its Regulation.- 11 Transcytosis of Macromolecules through the Blood—Brain Fluid Barriers in Vivo.- IV. Elimination Barriers.- 12 Renal Uptake and Disposal of Proteins and Peptides.- 13 Mechanisms for the Hepatic Clearance of Oligopeptides and Proteins: Implications for Rate of Elimination, Bioavailability, and Cell-Specific Drug Delivery to the Liver.- 14 The Immune System as a Barrier to Delivery of Protein Therapeutics.- V. Tissue Barriers.- 15 Extravasation and Interstitial Transport in Tumors.- 16 Tissue Barriers: Diffusion, Bulk Flow, and Volume Transmission of Proteins and Peptides within the Brain.