Abstract: Retro-inverted forms of GIT targeting agents that target specific receptor sites in vivo and/or promote uptake of active agents and/or enhance active site delivery across the GIT into the systemic circulation are provided. These retro-inverted peptides and compositions containing these retro-inverted peptides can be used to deliver an active agent, such as a drug or a drug-containing nano- or microparticle for treatment of a condition in a subject in need of the drug, in vivo. Additionally, the invention provides antibodies which are capable of immunospecifically binding the retro-inverted peptides.

Abstract: Retro-inverted forms of GIT targeting agents that target specific receptor sites in vivo and/or promote uptake of active agents and/or enhance active agent delivery across the GIT into the systemic circulation are provided. These retro-inverted peptides and compositions containing these retro-inverted peptides can be used to deliver an active agent, such as a drug or a drug-containing nano- or microparticle for treatment of a condition in a subject in need of the drug, in vivo. Additionally, the invention provides antibodies which are capable of immunospecifically binding the retro-inverted peptides.

Abstract: The invention provides an antibody or antibody fragment specific to a domain of a GIT targeting agent, such as a polyclonal antibody, monoclonal antibody, chimeric antibody, single chain antibody, a Fab fragment or a Fab expression library. In particular, the invention provides an antibody or antibody fragment, wherein the GIT targeting agent is selected from the group consisting of ZElan033 (PAX2 15 mer), ZElan088 (HAX42-2 20 mer) or ZElan053 (P31 D-form 16 mer). Numerous methods using these GIT targeting agent specific antibodies are disclosed.

Abstract: The invention provides an antibody or antibody fragment specific to a domain of a GIT targeting agent, such as a polyclonal antibody, monoclonal antibody, chimeric antibody, single chain antibody, a Fab fragment or a Fab expression library. In particular, the invention provides an antibody or antibody fragment, wherein the GIT targeting agent is selected from the group consisting of ZElan033 (PAX2 15 mer), ZElan088 (HAX42-2 20 mer) or ZElan053 (P31 D-form 16 mer). Numerous methods using these GIT targeting agent specific antibodies are disclosed.

Abstract: A method of identifying a peptide which permits or facilitates the transport of an active agent through a human or animal tissue. A predetermined amount of phage from a random phage library or a preselected phage library is administered in vivo or in situ to a site in an animal, such as into the gastro-intestinal tract. At a predetermined time, the phage which is transported across a tissue barrier is harvested at a harvesting site, such as in portal or systemic blood or brain tissue, which is separated from the site of administration by the tissue barrier to select transported phage. This transported phage is amplified in a host. This cycle of events is repeated (using the transported phage produced in the most recent cycle) a predetermined number of times to obtain a selected phage library containing phage which can be transported from the site of administration to the harvesting site.

Abstract: A method of identifying a peptide which permits or facilitates the transport of an active agent through a human or animal tissue. A predetermined amount of phage from a random phage library or preselected phage library is plated unto or brought into contact with a first side, preferably the apical side, of a tissue sample or polarized tissue cell culture. At a predetermined time, the phage which is transported to a second side of the tissue opposite the first side, preferably the basolateral side, is harvested to select transported phage. This modified phage is amplified in a host. This cycle of events is repeated (using the transported phage produced in the most recent cycle) a predetermined number of times to obtain a selected phage library containing phage which can be transported from the first side to the second side.

Abstract: A method of identifying a peptide which permits or facilitates the transport of an active agent through a human or animal tissue. A predetermined amount of phage from a random phage library or preselected phage library is plated unto or brought into contact with a first side, preferably the apical side, of a tissue sample or polarized tissue cell culture. At a predetermined time, the phage which is transported to a second side of the tissue opposite the first side, preferably the basolateral side, is harvested to select transported phage. This modified phage is amplified in a host. This cycle of events is repeated (using the transported phage produced in the most recent cycle) a predetermined number of times to obtain a selected phage library containing phage which can be transported from the first side to the second side.

Abstract: A method of identifying a peptide which permits or facilitates the transport of an active agent through a human or animal tissue. A predetermined amount of phage from a random phage library or a preselected phage library is administered in vivo or in situ to a site in an animal, such as into the gastro-intestinal tract. At a predetermined time, the phage which is transported across a tissue barrier is harvested at a harvesting site, such as in portal or systemic blood or brain tissue, which is separated from the site of administration by the tissue barrier to select transported phage. This transported phage is amplified in a host. This cycle of events is repeated (using the transported phage produced in the most recent cycle) a predetermined number of times to obtain a selected phage library containing phage which can be transported from the site of administration to the harvesting site.

Abstract: A method of identifying a peptide which permits or facilitates the transport of an active agent through a human or animal tissue. A predetermined amount of phage from a random phage library or preselected phage library is plated unto or brought into contact with a first side, preferably the apical side, of a tissue sample or polarized tissue cell culture. At a predetermined time, the phage which is transported to a second side of the tissue opposite the first side, preferably the basolateral side, is harvested to select transported phage. This modified phage is amplified in a host. This cycle of events is repeated (using the transported phage produced in the most recent cycle) a predetermined number of times to obtain a selected phage library containing phage which can be transported from the first side to the second side.