Fundamental concepts of injectable hydrogel based on natural polymer for malignant solid tumor: Types and characterization – Review

Cancer is a disease that affects a large number of people worldwide, and its treatment remains a key area of study. Current therapies often generate side effects that significantly impact patients' well-being; for this reason, it is essential to explore new methods, such as localized therapy, to reduce unwanted effects. In this context, injectable hydrogels based on natural polymers have emerged as an alternative drug delivery system for local cancer therapy. Natural polymers are particularly valuable due to their excellent biocompatibility, biodegradability, and ability to be functionalized, making them ideal candidates for designing hydrogels that can deliver drugs specifically to the tumor site while minimizing systemic toxicity. One of the key features of these systems is their sensitivity to stimuli like temperature, pH, or light; this allows them to transition from a solution state to a gel (sol-gel) in response to environmental changes, which can also promote the controlled release of anticancer drugs In addition to these advantages, the combination of hydrogels with nanoparticles leads to hybrid systems, which can further enhance the performance of drug delivery by overcoming the limitations of each component. This review provides an overview of injectable hydrogels based on natural polymers and their use in localized cancer therapy. It covers materials, advantages and disadvantages, sensitivity to stimuli, self-healing hydrogels, characterization techniques, and hybrid drug delivery systems. [Display omitted]