**5. Conclusions**

Stimuli-responsive hydrogels from a wide variety of natural and synthetic polymers provide a significant contribution in biomedical area especially for drug delivery applications. Over the last 10 years, the potential applications of stimuliresponsive hydrogels in textiles are rapidly advancing. Functionalized textiles integrated with stimuli-responsive hydrogels show improved moisture/temperature management, esthetic appeal, soft display, and enhanced protection against extreme environmental conditions. Stimuli-responsive hydrogels used in textiles are mainly thermoresponsive, pH-responsive, and furthermore dual-responsive (temperature and pH) in nature, and specific drug-loaded stimuli-responsive hydrogels are being applied for textile-based transdermal therapy. The polymers used in thermoresponsive hydrogels vary from synthetic polymers to nature polymers, and often, composites are developed for better functionalities. pH-responsive hydrogels include natural to synthetic polymers, and depending on the charge of polymers, the charge of pH-responsive hydrogel varies. For site-specific delivery of drug by pH-responsive hydrogels, the charge of hydrogels plays a significant role. Dualresponsive hydrogel includes both thermoresponsive polymer and pH-responsive polymer to show response to external pH and temperature changes. With the rapid development of dual responsive (pH/temperature) hydrogels, and their applications in textiles as drug delivery systems will develop smart textiles in near future with more functionalities.

#### **Acknowledgements**

This study was supported by the block grant of the Faculty of Applied Science and Textiles, The Hong Kong Polytechnic University (ref: 1-ZVLM).

**19**

**Author details**

Hung Hom, Hong Kong

provided the original work is properly cited.

Sudipta Chatterjee and Patrick Chi-leung Hui\*

\*Address all correspondence to: tchuip@polyu.edu.hk

*Stimuli-Responsive Hydrogels: An Interdisciplinary Overview*

*DOI: http://dx.doi.org/10.5772/intechopen.80536*

© 2018 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/ by/3.0), which permits unrestricted use, distribution, and reproduction in any medium,

Institute of Textiles and Clothing, The Hong Kong Polytechnic University,

*Stimuli-Responsive Hydrogels: An Interdisciplinary Overview DOI: http://dx.doi.org/10.5772/intechopen.80536*

*Hydrogels - Smart Materials for Biomedical Applications*

**Chemical constituents of dual-responsive** 

p(NIPAAm-*co*-hydroxyethyl methacrylate) (*temperature*), poly(L-glutamic acid) (*pH*)

pNIPAAm (*temperature*), vinyl-capped

pNIPAAm (*temperature*), glycidyl methacrylated

Stimuli-responsive hydrogels from a wide variety of natural and synthetic polymers provide a significant contribution in biomedical area especially for drug delivery applications. Over the last 10 years, the potential applications of stimuliresponsive hydrogels in textiles are rapidly advancing. Functionalized textiles integrated with stimuli-responsive hydrogels show improved moisture/temperature management, esthetic appeal, soft display, and enhanced protection against extreme environmental conditions. Stimuli-responsive hydrogels used in textiles are mainly thermoresponsive, pH-responsive, and furthermore dual-responsive (temperature and pH) in nature, and specific drug-loaded stimuli-responsive hydrogels are being applied for textile-based transdermal therapy. The polymers used in thermoresponsive hydrogels vary from synthetic polymers to nature polymers, and often, composites are developed for better functionalities. pH-responsive hydrogels include natural to synthetic polymers, and depending on the charge of polymers, the charge of pH-responsive hydrogel varies. For site-specific delivery of drug by pH-responsive hydrogels, the charge of hydrogels plays a significant role. Dualresponsive hydrogel includes both thermoresponsive polymer and pH-responsive polymer to show response to external pH and temperature changes. With the rapid development of dual responsive (pH/temperature) hydrogels, and their applications in textiles as drug delivery systems will develop smart textiles in near future

*The chemical nature and biomedical applications of dual-responsive (pH and temperature) hydrogels.*

pNIPAAm (*temperature*), chitosan (*pH*) Drug delivery application [136]

pNIPAAm (*temperature*), PAA (*pH*) Drug delivery application [77, 140] pNIPAAm (*temperature*), PDMAEMA (*pH*) Drug delivery application [142, 143]

pNIPAAm (*temperature*), polyurethane (*pH*) Textile application [147]

pNIPAAm (*temperature*), chitosan (*pH*) Textile application (water and

**Biomedical application of dual-**

Drug delivery application [135]

Drug delivery application [144]

Drug delivery application [146]

**References**

[138, 139]

**responsive hydrogel**

moisture management)

This study was supported by the block grant of the Faculty of Applied Science

and Textiles, The Hong Kong Polytechnic University (ref: 1-ZVLM).

**18**

**5. Conclusions**

**Table 3.**

polyurethane (*pH*)

**hydrogel**

chitosan (*pH*)

with more functionalities.

**Acknowledgements**
