Tokyo University of Science develops a highly functional wound treatment gel developed using seaweed and carbonated water

A research group led by Graduate Student Ryota Teshima of the Department of Chemistry at the Graduate School of Science at Tokyo University of Science succeeded in developing a low-adhesion and low-swelling wound treatment hydrogel using a convenient synthesis method of adding carbonated water to a solution of alginate (a seaweed component) and calcium carbonate (CaCO₃). The developed hydrogel exhibited high efficacy in wound healing and prevented transient dilation of the wound site, which is often observed with conventional gels. The results are expected to lead to clinical applications of environmentally friendly and highly functional therapeutic gels. The study results were published in the International Journal of Biological Macromolecules, an international scientific publication, on November 8.

Hydrogels are 3-dimensional (3D) mesh structures made up of a cross-linked polymer, within which a substantial amount of water is incorporated. Such gels have potential clinical application as a medical material.

Previously, adhesiveness (to allow stretching with the skin movement) and swelling (to facilitate the absorption of body fluid) were considered critical properties in the design of a wound healing gel. However, if the hydrogel attached to the skin absorbs wound exudate and swells, it may pull on the wound site, creating a risk of wound site dilation.

In the current study, three types of alginate gels with different CaCO₃ concentrations were formed by adding carbonated water to mixed solutions of potassium alginate and CaCO₃. For all three alginate gels, the scanning electron microscopy and gel strength measurement results showed the formation of a 3D mesh structure resistant to change. The results also revealed that an increase in the CaCO₃ concentration leads to a reduction in gelation time as well as decreases the levels of gel transparency and cross-linking.

Next, the biocompatibility and cell adhesiveness of the alginate gels were assessed using normal human dermal fibroblasts (NHDF). The results showed that the NHDF survival rate was nearly 100% in all of the alginate gels. NHDF cells cultured polystyrene culture-cell plates were elongated and adherent, whereas NHDF cells cultured on alginate gel formed a three-dimensional aggregate structure called a spheroid. This indicated that cell adhesion was low on the alginate gel surface. The developed gel was further compared with a clinically used hydrogel wound dressing (Viewgel), and its low-adhesion and low-swelling properties were confirmed.

The developed hydrogel and Viewgel were respectively applied to a mouse wound model to compare their wound treatment effects through observations and measurements over time. No significant difference in healing effects was found between the two hydrogels, indicating the high treatment efficacy of the newly developed material. Importantly, the area of the wound site covered with Viewgel dilated transiently because of the high-adhesion and high-swelling properties of the gel, whereas suppression of dilation was observed in the wound site covered with the alginate-based gel.

Teshima remarked, "I worked on the current study based on experiments I had conducted since I was a junior high-school student. As this highly functional wound treatment gel was successfully fabricated using waste materials, this development may contribute to environmental issues and sustainable development goals. Because of the simplicity of this hydrogel preparation method, the ability to tailor the material to individual needs in different clinical settings may be possible. With an aim for clinical application, we will further advance our research in collaboration with the Department of Pharmacy at our university and with companies."

Journal Information
Publication: International Journal of Biological Macromolecules
Title: Low-adhesion and low-swelling hydrogel based on alginate and carbonated water to prevent temporary dilation of wound sites
DOI: 10.1016/j.ijbiomac.2023.127928