Research Progress on Injectable Hydrogels and Their Biomedical Applications

Hydrogels are a class of materials with a three-dimensional network structure formed by the crosslinking of hydrophilic polymer chains in water, possessing a wide range of tunable physical and chemical properties. Hydrogels, as intelligent and versatile materials, have demonstrated significant potential in various biomedical applications, including drug delivery, tissue engineering, and regenerative medicine. However, traditional hydrogels often face limitations in formulation and application methods. Injectable hydrogels have attracted extensive attention due to their unique advantages, typically formed through rapid sol-gel phase transitions or in situ chemical polymerization. Additionally, these hydrogels can be implanted minimally invasively via a simple syringe, allowing the direct injection of bioactive molecules or cells to the target site, thereby enabling controlled drug release, minimally invasive administration, and precise delivery. This review summarizes the latest research progress of injectable hydrogels in biomedical applications and discusses their potential and limitations in future biomedical fields.