This review discusses the development and application of stimuli-responsive hydrogels based on natural polymers for breast cancer diagnosis and treatment. Breast cancer is the most common malignancy among women, and conventional therapies have limitations in efficacy and patient compliance. Stimuli-responsive hydrogels, which mimic the physicochemical properties of soft tissue, offer promising solutions for targeted drug delivery and enhanced therapeutic outcomes. Natural polymers, such as polysaccharides and polypeptides, are widely used due to their biocompatibility, biodegradability, and modifiable surface properties. These hydrogels can respond to various external stimuli, including pH, temperature, light, ultrasonic, enzyme activity, glucose levels, magnetic fields, redox conditions, and electric fields. This responsiveness allows for precise control over drug release and therapeutic agent delivery at specific sites, enhancing the efficacy of treatments while minimizing side effects. The review highlights several key aspects: 1. **Preliminary Introduction**: It provides an overview of breast cancer, its global impact, and the challenges of conventional treatments. 2. **Natural Polymer Hydrogels**: Discusses the types of natural polymers used, their advantages, and the factors affecting their formulation. 3. **Stimuli-Responsive Hydrogels**: - **pH-Responsive Hydrogels**: These hydrogels can respond to changes in pH, which is significant in breast cancer due to the acidic environment of tumors. - **Glucose-Responsive Hydrogels**: These hydrogels can detect and respond to glucose levels, which are higher in cancerous tissues. - **Redox-Responsive Hydrogels**: These hydrogels can respond to redox conditions, particularly the high levels of glutathione (GSH) in tumor cells. - **Enzyme-Responsive Hydrogels**: These hydrogels can be triggered by enzymes like hyaluronidase, which are highly expressed in tumor microenvironments. - **Temperature-Responsive Hydrogels**: These hydrogels can respond to temperature changes, which are typical in breast cancer due to the elevated temperatures in tumors. - **Light-Responsive Hydrogels**: These hydrogels can be triggered by light, particularly near-infrared (NIR) light, for precise and controlled drug release. - **Ultrasonic-Responsive Hydrogels**: These hydrogels can respond to ultrasound, allowing for localized and targeted drug delivery. - **Electric-Responsive Hydrogels**: These hydrogels can be triggered by electrical fields, providing precise control over drug release. The review also presents several case studies and in vitro/in vivo experiments demonstrating the effectiveness of these hydrogels in breast cancer treatment. Overall, stimuli-responsive hydrogels based on natural polymers show great potential in improving the diagnosis and treatment of breast cancer by providing targeted and controlled drug delivery, enhancing therapeutic efficacy, and reducing side effects.This review discusses the development and application of stimuli-responsive hydrogels based on natural polymers for breast cancer diagnosis and treatment. Breast cancer is the most common malignancy among women, and conventional therapies have limitations in efficacy and patient compliance. Stimuli-responsive hydrogels, which mimic the physicochemical properties of soft tissue, offer promising solutions for targeted drug delivery and enhanced therapeutic outcomes. Natural polymers, such as polysaccharides and polypeptides, are widely used due to their biocompatibility, biodegradability, and modifiable surface properties. These hydrogels can respond to various external stimuli, including pH, temperature, light, ultrasonic, enzyme activity, glucose levels, magnetic fields, redox conditions, and electric fields. This responsiveness allows for precise control over drug release and therapeutic agent delivery at specific sites, enhancing the efficacy of treatments while minimizing side effects. The review highlights several key aspects: 1. **Preliminary Introduction**: It provides an overview of breast cancer, its global impact, and the challenges of conventional treatments. 2. **Natural Polymer Hydrogels**: Discusses the types of natural polymers used, their advantages, and the factors affecting their formulation. 3. **Stimuli-Responsive Hydrogels**: - **pH-Responsive Hydrogels**: These hydrogels can respond to changes in pH, which is significant in breast cancer due to the acidic environment of tumors. - **Glucose-Responsive Hydrogels**: These hydrogels can detect and respond to glucose levels, which are higher in cancerous tissues. - **Redox-Responsive Hydrogels**: These hydrogels can respond to redox conditions, particularly the high levels of glutathione (GSH) in tumor cells. - **Enzyme-Responsive Hydrogels**: These hydrogels can be triggered by enzymes like hyaluronidase, which are highly expressed in tumor microenvironments. - **Temperature-Responsive Hydrogels**: These hydrogels can respond to temperature changes, which are typical in breast cancer due to the elevated temperatures in tumors. - **Light-Responsive Hydrogels**: These hydrogels can be triggered by light, particularly near-infrared (NIR) light, for precise and controlled drug release. - **Ultrasonic-Responsive Hydrogels**: These hydrogels can respond to ultrasound, allowing for localized and targeted drug delivery. - **Electric-Responsive Hydrogels**: These hydrogels can be triggered by electrical fields, providing precise control over drug release. The review also presents several case studies and in vitro/in vivo experiments demonstrating the effectiveness of these hydrogels in breast cancer treatment. Overall, stimuli-responsive hydrogels based on natural polymers show great potential in improving the diagnosis and treatment of breast cancer by providing targeted and controlled drug delivery, enhancing therapeutic efficacy, and reducing side effects.