Small molecule drugs often exhibit poor solubility, inefficient cellular uptake, and rapid clearance from the body, limiting their therapeutic efficacy. Additionally, these drugs typically lack the ability to selectively target diseased tissues, leading to undesirable side effects. Stimuli-responsive nanocarriers, particularly those based on biodegradable and biocompatible biopolymers, offer a promising solution to overcome these challenges in drug delivery. Biopolymer-based nanocomposites can be engineered to exhibit multi-stimuli responsiveness and tunable properties, enabling prolonged circulation, targeted accumulation, enhanced penetration, and controlled drug release at the site of disease. While endogenous stimuli, such as changes in pH, redox potential, or enzyme activity, provide some benefits, the variability between patients and limited tissue penetration can be limiting. Leveraging the combined effects of exogenous and endogenous stimuli through multi-stimuli-responsive carriers presents a more effective approach for precise drug delivery and improved therapeutic outcomes. This can be achieved through the design of biopolymer-based nanocomposites that respond to external triggers, such as light, temperature, or magnetic fields, in addition to internal physiological cues. Furthermore, the integration of stimuli-responsive biopolymer-based nanocomposites with 4D printing technology opens up new possibilities for advanced medical devices. 4D printing refers to the fabrication of smart materials that can change shape, properties, or function over time in response to environmental stimuli. By incorporating stimuli-responsive biopolymer-based nanocomposites into 4D-printed medical devices, it becomes possible to create customized, dynamic, and adaptive structures that can interact with the body and deliver therapeutics in a spatiotemporally controlled manner. This approach has the potential to revolutionize the field of personalized medicine and targeted drug delivery. This chapter provides a comprehensive overview of the use of stimuli-responsive biopolymer-based nanocomposites in medicine and their potential applications in areas such as 4D printing for advanced medical devices. The discussion includes the design principles, fabrication methods, and specific examples of how these smart materials can be leveraged to improve drug delivery and therapeutic outcomes.