Smart polymers for peptide and protein parenteral sustained delivery

Smart polymers have revolutionized the field of polymeric drug delivery to achieve sustained and/or targeted delivery of protein therapeutics. These polymers exhibit a non-linear response to a small stimulus leading to a macroscopic alteration in their structure/properties. The stimulus is categorized as physical, chemical or biochemical and could be internal, external, single or a combination of two or more. A broad classification of smart polymers, their fabrication and refinement of release characteristics, advantages, limitations and applications have been highlighted in this review. Special emphasis has been placed on temperature and phase-sensitive polymers to deliver protein therapeutics.