A comprehensive review of conventional and stimuli-responsive delivery systems for bioactive peptides: from food to biomedical applications

Bioactive peptides have garnered significant attention for their health benefits and therapeutic potential across food and biomedical industries. However, their application is often limited by poor stability, low bioavailability, and susceptibility to degradation. This review provides a comprehensive overview of conventional and stimuli-responsive delivery systems designed to enhance their stability, bioavailability and efficacy via targeted delivery and controlled release in various applications. The conventional delivery systems, including emulsion-, nanoparticle,- liposome-, and hydrogel-based delivery systems, offer effective solutions for enhancing the stability and bioavailability of food-derived peptides during storage, processing, and absorption after ingestion. Their formulations and preparation techniques are crucial for the delivery systems to be tailored to the specific characteristics of peptides, optimizing their stability, encapsulation efficiency, and release profiles. Moreover, this review also discusses stimuli-responsive delivery systems for emerging biochemical applications of therapeutic peptides. For such applications, the carriers are engineered to respond dynamically to environmental triggers, including pH changes, temperature fluctuations, enzymatic activity, light exposure, ultrasound, and magnetic fields. These systems represent a significant advancement in peptide delivery, which is particularly beneficial for therapeutic applications requiring localized or targeted delivery, such as inflamed or cancerous tissues. Understanding and leveraging these responsive mechanisms enables the delivery systems to be further designed to enhance bioavailability and therapeutic efficacy while minimizing side effects. By integrating insights from these delivery systems, this review aims to guide the development of effective delivery strategies for addressing challenges and optimizing bioactive peptide utilization in food and biomedical fields. Graphical Abstract