The latest advances in drug delivery systems are aimed at delivering drugs in a controlled fashion both temporally and spatially. Polymers have recently been employed in these approaches for drug delivery, tissue engineering, cell encapsulation, the fabrication of medical devices, and a diversity of other biomedical applications. These recent successful applications have demonstrated the superior potential of such polymeric drug-delivery systems in biomedicine.

This Special Issue aims to provide an updated account of recent advances in the synthesis, characterization, engineering, and use of polymers, being synthetic or natural, for drug delivery and sustained drug release. We thank all authors for reporting developed novel polymer-based carriers in therapeutics and diagnoses that overcome the limitations associated with drug administration and enhance patients' quality of life.