Patent ID: 7713737

Claim:
An isolated delivery construct, comprising: a)—a receptor binding domain, b)—a transcytosis domain, c)—a peptide, polypeptide, or protein to be delivered to a subject, and d)—a cleavable linker, wherein upon transcytosis of said delivery construct across a normal, polarized epithelial cell in said subject, said cleavable linker is cleaved at a basal-lateral membrane of the polarized epithelial cell or in the plasma in said subject, and said peptide, polypeptide, or protein is separated from the receptor binding domain and the transcytosis domain, by an enzyme that i) exhibits greater activity at a basal-lateral membrane of a normal, polarized epithelial cell in said subject than at an apical membrane of the polarized epithelial cell, or ii) exhibits greater activity in the plasma in said subject than at an apical membrane of the polarized epithelial cell in the subject.