Polysaccharide-based injectable hydrogels for targeted drug delivery: advances and challenges

Area of Science:

• Biomaterials Science
• Drug Delivery Systems
• Polymer Chemistry

Background:

• Precision medicine necessitates advanced drug delivery platforms.
• Injectable hydrogels derived from natural polysaccharides offer biocompatibility and biodegradability.
• Polysaccharides are versatile for developing targeted and controlled release systems.

Purpose of the Study:

• To systematically review natural polysaccharides for injectable hydrogel development.
• To evaluate structural features and design strategies for polysaccharide hydrogel injectability.
• To discuss targeting mechanisms and controlled release strategies for hydrogel-based therapies.

Main Methods:

• Review of five major polysaccharide classes: chitosan, hyaluronic acid, sodium alginate, cellulose, and oxidized dextran.
• Analysis of shear-thinning and in situ gelling strategies based on dynamic covalent crosslinking and physical interactions.
• Evaluation of hydrogel mechanical properties (storage moduli 10^2-10^4 Pa) for injectability.

Main Results:

• Polysaccharide hydrogels exhibit rapid gelation (seconds to minutes) and tunable mechanical strength.
• Mechanisms for passive and active targeting are discussed.
• Environment-responsive controlled release is a key feature of these hydrogels.

Conclusions:

• Polysaccharide-based injectable hydrogels provide a framework for rational design.
• These hydrogels show promise for tumor microenvironment therapy, chronic disease treatment, ocular drug delivery, and infection site targeting.
• The review facilitates the clinical translation of efficient and precise drug delivery platforms.