Peptides which enhance transport across tissues and methods of identifying and using the same

A method of identifying a peptide which permits or facilitates the transport of an active agent through a human or animal tissue, comprising the steps of:

• (a) administering in vivo or in situ to the gastro-instestinal tract of an animal a predetermined amount of phage from a random phage library or a preselected phage library;
• (b) at a predetermined time harvesting phage which is transported to the portal circulatory system or to the systemic circulatory system of the animal to select transported phage;
• (c) amplifying the transported phage in a host;
• (d) repeating in order step (a) using the transported phage obtained in step (b) and amplified in step (c) and steps (b) and (c) a predetermined number of times to obtain a selected phage library containing phage which can be transported from the gastro-intestinal tract to the portal circulatory system or to the systemic circulatory system of the animal;
• and
• (e) determining the identity of at least one peptide coded by phage in the selected phage library to identify a peptide which permits or facilitates the transport of an active agent through a human or animal tissue.

A method of identifying a peptide which permits or facilitates the internalization of an active agent into human or animal tissue, comprising the steps of:

• (a) administering in vivo or in situ to a site adjacent a selected tissue in an animal a predetermined amount of phage from a random phage library or a preselected phage library;
• (b) at a predetermined time harvesting phage from the selected tissue to select tissue internalized phage, wherein the harvesting comprising the steps of:
• (i) homognizing the selected tissue to obtain a homogenate:
• and
• (ii) washing the homogenate;
• (c) amplifying the tissue internalized phage in a host;
• (d) determining the identity of at least one peptide coded by tissue internalized phage to identify a peptide which permits or facilitates the internalization of an active agent into a human or animal tissue or transport of the active agent through human or animal tissue.

A method of identifying a peptide which permits or facilitates the transport of an active agent through a human or animal tissue, comprising the steps of:

• (a) administering in vivo or in situ to a site adjacent a selected tissue in an animal a predetermined amount of phage from a random phage library or a preselected phage library;
• (b) at a predetermined time harvesting phage from the selected tissue to obtain tightly bound phage, wherein the harvesting comprises the steps of:
• (i) washing the selected tissue to obtain washed tissue;
• and
• (ii) homogenized the washed tissue
• (c) amplifying the tightly bound phage in a host;
• and
• (d) determining the identity of at least one peptide coded by tightly bound phage to identify a peptide which permits or facilitates the internalization of an active agent into a human or animal tissue.

A method of identifying a peptide which permits or facilitates the transport of an active agent through a human or animal tissue, comprising the steps of:

• (a) administering in vivo or in situ to the gastro-instestinal tract of an animal a predetermined amount of phage from a random phage library or a preselected phage library;
• (b) at a predetermined time harvesting phage which is transported to the brain tissue of the animal to select transported phage;
• (c) amplifying the transported phage in a host;
• (d) repeating in order step (a) using the transported phage obtained in step (b) and amplified in step (c) and steps (b) and (c) a predetermined number of times to obtain a selected phage library containing phage which can be transported from the gastro-intestinal tract to the brain tissue of the animal;
• and
• (e) determining the identity of at least one peptide coded by phage in the selected phage library to identify a peptide which permits or facilitates the transport of an active agent through a human or animal tissue.