Table 2.

Comparative analysis of single, dual, and multi-responsive hydrogels.

Type	Stimuli	Advantages	Limitations	Key biomedical applications	Ref.
Single-responsive	One (e.g., pH, temp, redox)	Simple, cost-effective, predictable response	Limited adaptability to complex biological environments	Topical drug delivery, wound healing	[[124], [125], [126]]
Dual-responsive	Two (e.g., pH + temp)	Improved specificity and control	Increased formulation complexity	Injectable DDS, inflammation targeting	[127]
Multi-responsive	≥3 (e.g., pH + temp + redox)	Highly tunable, suitable for complex conditions	Complex synthesis, regulatory barriers	Tumor therapy, TE scaffolds	[128]