Polymer-drug conjugates: recent advances and future perspectives

Polymer-drug conjugates (PDC) have exhibited clinical and commercial success in the field of drug delivery. A polymeric backbone, linker, targeting moiety, and drug constitute the building blocks of PDCs. Current attention is focusing on natural polymeric carriers, in particular the concept of graft copolymers, such as a combination of polymers and polysaccharides, to explore dual benefits such as combined vehicles and targeting moieties. Polymer heterogeneity, synthesis of PDCs, broad molecular weight distribution, conjugate variability, immunogenicity of polymers, safety, stability, and stringent regulatory approval are the major obstacles to the successful transition of PDCs to the clinic. In this review, we discuss natural and synthetic PDCs combined with computational modeling for diverse pharmaceutical and biomedical applications.