TY - JOUR
T1 - A pH-Indicating colorimetric tough hydrogel patch towards applications in a substrate for smart wound dressings
AU - Liu, Li
AU - Li, Xinda
AU - Nagao, Masanori
AU - Elias, Anastasia L.
AU - Narain, Ravin
AU - Chung, Hyun Joong
N1 - Funding Information:
Acknowledgments: We would like to thank CIHR/NSERC (Collaborative Health Research Projects; Chung) for funding and Canada Foundation for Innovation (CFI) Leader’s Opportunity Fund (Elias) for the use of Instron tensile tester. We thank J.M. Rieger (Institute for Reconstructive Sciences in Medicine (iRSM)) for inspirational discussions, A. de Klerk (U. Alberta) for equipment use of a rotary evaporator, and D. Sauvageau (U. Alberta) for equipment use of an isothermal incubator.
Publisher Copyright:
© 2017 by the authors.
PY - 2017/10/26
Y1 - 2017/10/26
N2 - The physiological milieu of healthy skin is slightly acidic, with a pH value between 4 and 6, whereas for skin with chronic or infected wounds, the pH value is above 7.3. As testing pH value is an effective way to monitor the status of wounds, a novel smart hydrogel wound patch incorporating modified pH indicator dyes was developed in this study. Phenol red (PR), the dye molecule, was successfully modified with methacrylate (MA) to allow a copolymerization with the alginate/polyacrylamide (PAAm) hydrogel matrix. This covalent attachment prevented the dye from leaching out of the matrix. The prepared pH-responsive hydrogel patch exhibited a porous internal structure, excellent mechanical property, and high swelling ratio, as well as an appropriate water vapour transmission rate. Mechanical responses of alginate/P(AAm-MAPR) hydrogel patches under different calcium and water contents were also investigated to consider the case of exudate accumulation into hydrogels. Results showed that increased calcium amount and reduced water content significantly improved the Young's modulus and elongation at break of the hydrogels. These characteristics indicated the suitability of hydrogels as wound dressing materials. When pH increased, the color of the hydrogel patches underwent a transition from yellow (pH 5, 6 and 7) to orange (7.4 and 8), and finally to red (pH 9). This range of color change matches the clinically-meaningful pH range of chronic or infected wounds. Therefore, our developed hydrogels could be applied as promising wound dressing materials to monitor the wound healing process by a simple colorimetric display, thus providing a desirable substrate for printed electronics for smart wound dressing.
AB - The physiological milieu of healthy skin is slightly acidic, with a pH value between 4 and 6, whereas for skin with chronic or infected wounds, the pH value is above 7.3. As testing pH value is an effective way to monitor the status of wounds, a novel smart hydrogel wound patch incorporating modified pH indicator dyes was developed in this study. Phenol red (PR), the dye molecule, was successfully modified with methacrylate (MA) to allow a copolymerization with the alginate/polyacrylamide (PAAm) hydrogel matrix. This covalent attachment prevented the dye from leaching out of the matrix. The prepared pH-responsive hydrogel patch exhibited a porous internal structure, excellent mechanical property, and high swelling ratio, as well as an appropriate water vapour transmission rate. Mechanical responses of alginate/P(AAm-MAPR) hydrogel patches under different calcium and water contents were also investigated to consider the case of exudate accumulation into hydrogels. Results showed that increased calcium amount and reduced water content significantly improved the Young's modulus and elongation at break of the hydrogels. These characteristics indicated the suitability of hydrogels as wound dressing materials. When pH increased, the color of the hydrogel patches underwent a transition from yellow (pH 5, 6 and 7) to orange (7.4 and 8), and finally to red (pH 9). This range of color change matches the clinically-meaningful pH range of chronic or infected wounds. Therefore, our developed hydrogels could be applied as promising wound dressing materials to monitor the wound healing process by a simple colorimetric display, thus providing a desirable substrate for printed electronics for smart wound dressing.
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U2 - 10.3390/polym9110558
DO - 10.3390/polym9110558
M3 - Article
AN - SCOPUS:85033377968
SN - 2073-4360
VL - 9
JO - Polymers
JF - Polymers
IS - 11
M1 - 558
ER -