KAIST develops 5x stronger adhesive hydrogel for wound care
Last update on Jun 12, 2026
Formulators and product developers working on bio-based adhesives, sealants, or adhesive wound dressings have new performance data to evaluate. A KAIST research team led by Professor Haeshin Lee has demonstrated that introducing tannic acid, a natural polyphenol, into κ-Carrageenan hydrogel systems significantly increases mechanical strength, enhances surface adhesion, and allows degradation rate to be tuned. The findings were published on April 21st in Biomimetics (DOI: 10.3390/biomimetics11040290).
What the research addresses
κ-Carrageenan is a natural polymer derived from red seaweed, already in use as a food-grade thickening and gelling agent. As an adhesive or sealant base material, its performance has been limited by the sulfate groups within its molecular structure: these generate intermolecular repulsion that prevents the formation of a dense, mechanically robust network.
The KAIST team investigated whether tannic acid, a polyphenol with multiple galloyl binding sites, could interact with those sulfate groups to bridge molecules, reinforce the network, and modify surface adhesion behavior. According to the study, the sulfate groups that previously constrained performance became the primary binding sites once tannic acid was introduced.
Reported performance figures
The research team reports the following outcomes:
- Storage modulus reached approximately 1,632 Pa in the tannic acid–reinforced formulation, versus approximately 294 Pa for the pure κ-Carrageenan control, a more than fivefold increase in gel firmness and elasticity.
- The reinforced hydrogel demonstrated strong adhesion to both skin surfaces and rough surfaces in experimental conditions.
- Degradation rate was adjustable: in simulated gastrointestinal environment testing, the system showed accelerated degradation alongside maintained adhesion, suggesting the balance between bonding strength and end-of-life degradability can be designed into the formulation.
- The reinforcement effect was consistent regardless of when tannic acid was introduced relative to gel formation, indicating stable multi-point crosslinking across the network.
The research team notes that these outcomes were achieved using only food-grade natural ingredients, without complex chemical synthesis. According to Professor Haeshin Lee, "The mechanical strength, adhesiveness, and degradation behavior of hydrogel can be designed together using only naturally derived materials."
According to the publication, the design approach may be relevant to:
- Bio-based adhesives and sealant coatings requiring surface adhesion to varied substrates
- Wound healing dressings with adhesion and controlled degradation requirements
- Transdermal drug delivery patches
- Tissue engineering scaffolds
- Food encapsulation and cosmetic skin-adhering formulations