Smart materials are engineered materials that have one or more properties that are introduced in a controlled fashion by surrounding stimuli. Engineering of biomacromolecules like proteins into a smart material call for meticulous artistry. Peptides have grabbed notable attention as a preferred source for smart materials in the medicinal field, promoted by their versatile chemical and biophysical attributes of biocompatibility, and biodegradability. Recent advances in the synthesis of multifunctional peptides have proliferated their application in diverse domains: agriculture, nanotechnology, medicines, biosensors, therapeutics, and soft robotics. Stimuli such as pH, temperature, light, metal ions, and enzymes have vitalized physicochemical properties of peptides by augmented sensitivity, stability, and selectivity. This review elucidates recent (2018−2021) advances in the design and synthesis of smart materials, from stimuliresponsive peptides followed by their biomedical and therapeutic applications.

In the past few years, bioactive peptides obtained from natural resources have been seeking more attention due to their ability to prevent the risk of dreadful conditions such as hypertension, cancers, cholesterols, cardiovascular diseases, etc. Also, bioactive peptides offer much potential as nutraceuticals or functional food components. Proteins from food, plants, animals, dairy products, etc. are chemically or enzymatically hydrolyzed or fermented in the presence of microbes to produce bioactive peptides. They are antioxidant, antihypertensive, anti-inflammatory, antiproliferative, antibacterial, anticancer, antimicrobial, and some also show multiple bioactivities. This paper reviews recent progress (2020-2022) on bioactive peptides derived from food, animals, plants, and dairy products. Emphasis is given to their production, purification, and potential use for health promotions and medicinal applications.