Stimuli-responsive peptide-based biomaterials as drug delivery systems

Stimuli-responsive proteins have gained a wide spread interest as functional biomaterials in drug delivery area. However, particular attention has been diverted to peptide-based materials due to their adaptability and reliable practical utility in biomedical applications under a range of physiological situations. Peptides exhibit a high degree of chemical and biophysical versatility, biocompatibility, and biodegradability compared to other responsive systems. Several peptide motifs have been identified to undergo significant changes in conformation as a result of their response to both internal and external stimuli including light, pH, temperature, enzymes, ionic species and redox reactions. Understanding the structure and functions of peptides both at micro and macro levels is necessary before they can be used as nano devices, as biosensors, in regenerative tissue engineering and in drug delivery. The present review provides an overview of the peptide-based stimuli responsive materials, their design and discussion of their potential setbacks and opportunities for further exploration in drug delivery applications. The design of peptide-based materials of desired architectures, their properties and potential applications will be discussed covering the literature of the past decade, with a focus on their responsiveness to external and internal stimuli.