| 摘要 |
<p>Methods and compositions for transporting drugs and macromolecules across biological membranes are disclosed. In one embodiment, the invention includes a method for enhancing transport of a selected compound across a biological membrane, wherein a biological membrane is contacted with a conjugate containing a biologically active agent that is covalently attached to a transport polymer. In one embodiment, the polymer consists of from 6 to 25 subunits, at least 50% of which contain a guanidino or amidino sidechain moiety. The polymer is effective to impart to the attached agent a rate of trans-membrane transport across a biological membrane that is greater than the rate of trans-membrane transport of the agent in non-conjugate form. The transport-enhancing polymers are exemplified, in a preferred embodiment, by peptides in which arginine residues constitute the subunits. Such a polyarginine peptide may be composed of either all D-, all L- or mixed D- and L-arginines, and may include additional amino acids. More preferably, at least one, and preferably all of the subunits are D-arginine residues, to enhance biological stability of the polymer during transit of the conjugate to its biological target.</p> |
