Asymmetric bifunctional silyl (ABS) monomers comprising covalently linked pharmaceutical, chemical and biological agents are described. These agents can also be covalently bound via the silyl group to delivery vehicles for delivering the agents to desired targets or areas. Also described are delivery vehicles which contain ABS monomers comprising covalently linked agents and to vehicles that are covalently linked to the ABS monomers. The silyl modifications described herein can modify properties of the agents and vehicles, thereby providing desired solubility, stability, hydrophobicity and targeting.
