Site-Targeted Drug Delivery Systems: Polymeric Carriers

Polymeric carriers enhance site-targeted drug delivery, increasing efficacy while minimizing off-target effects.

They consist of a biodegradable polymeric backbone, a homing device for targeting, functional chains that enhance physicochemical properties, and a cleavable spacer for controlled drug release.

Common polymers include polyethyleneimine, polylysine, chitosan, dextran, and PEG. These are employed to deliver proteins and peptides and in gene therapies.

The homing device is a molecular recognition component, such as monoclonal antibodies or sugar moieties, that enables selective binding to target tissues.

Adding solubilizers improves physicochemical properties, such as aqueous solubility, enhancing drug transport and cellular uptake.

A spacer covalently links the drug to the carrier, facilitating controlled release through various mechanisms.

Micro- and nanoparticles improve drug stability and controlled release; smaller nanoparticles penetrate deeper into tissues.

Advances in polymeric drug delivery improve cancer and gene therapy treatments and controlled-release formulations.