Patent ID: 8440623

Claim:
A method of delivering a peptide into the brain of a mammalian subject, comprising: administering into the bloodstream of a mammalian subject a hydrophilic polymer-peptide conjugate consisting of a peptide that is either biphalin or [D-Pen 2 ,D-Pen 5 ]enkephalin (DPDPE) covalently linked to one or more water-soluble polymer chains having a molecular weight from about 2,000 daltons to about 100,000 daltons and selected from polyethylene glycol and a copolymer of polyethylene glycol and polypropylene glycol, to thereby transport the conjugate across the blood-brain barrier of the subject, wherein the one or more water-soluble polymer chains optionally comprises an imaging, diagnostic, or neuroactive agent covalently attached thereto.