Preface Free

Without doubt, smart hydrogels and their application in the medical and biomedical domains have increasingly taken a central position in the last few years. This is because of their three-dimensional (3D) crosslinked network structure, hydrophilicity, and ability to imbibe a significant amount of water and mimic the extracellular matrix (ECM). They are a unique group of biocompatible, often biodegradable, and non-toxic substances, which can act as scaffolds and can mimic the properties of various tissues of the body. Hydrogels can be applied using minimally invasive procedures, and their adaptive behavior following injection makes them appealing for use in reparative and regenerative therapy. These attributes allow the development and introduction of innovative treatment possibilities, which have been very limited in the past. The use of smart hydrogels will help regenerate lost tissues and organs, and address the problem of shortage in tissues and organs available for transplantation.

Scientists have been working to engineer smart hydrogels by modifying the physical and chemical properties of the hydrogel-forming polymers, and the terms “intelligent” and “smart” hydrogels have been introduced. Smart hydrogels can respond to local or external stimuli, such as changes in pH, temperature, enzymatic environment, ionic strength, light, or magnetic and electric fields. In addition, smart hydrogels exhibited great potential for use in remotely controllable therapy, including targeted drug delivery, tissue engineering, regenerative medicine, and development of artificial organs. The responsiveness of smart hydrogels allowed their application in fields such as trigger-induced drug delivery and disease-responsive therapies. Recently, in the quest for such essential intelligent materials, various types of hydrogels that include self-healing, conductive, shape-memory, environmentally-responsive, self-assembling and supramolecular hydrogels have been developed and their features have been investigated for a wide range of applications.

This book is timely and essential for those working in the field of biomaterials and their biomedical applications. We did our best to make it as comprehensive as possible. In addition to covering important aspects of basic science related to biomaterials from which smart hydrogels are made, the book also provides a succinct discussion of the various strategies for leveraging properties specific to smart injectable hydrogels and their applications.

Chapter 1 deals with the introduction of the book, and the preparation and applications of smart hydrogels. Chapter 2 emphasizes the physical, chemical and biological characteristics of injectable smart hydrogels and Chapter 3 surveys various techniques, commonly employed in the characterization of injectable hydrogels. Chapter 4 dwells on the emerging trends in the development and prospects of injectable hydrogels. The crosslinking strategies often employed for the design of these smart hydrogels are thoroughly reviewed in Chapter 5, and click chemistry-based injectable hydrogels are well reported in Chapter 6. Chapters 7 and 8 focus on naturally-derived smart hydrogels such as polysaccharide- and protein-based injectable smart hydrogels for biomedical applications. Chapters 9–18 deal with the application of smart hydrogels in different biomedical fields. These include the treatment of infections, wound management, ophthalmology, regeneration of bone and cartilage, regeneration of craniomaxillofacial bone, treatment of osteoarthritis, myocardial infarction therapy, spinal cord regeneration and localized cancer therapy. The concluding Chapter 19 highlights the current and possible future prospects of smart hydrogels.

The book will provide an essential resource to academics, industry, regulators and clinicians to develop new innovative injectable smart hydrogels and translate them into clinical solutions.

Jagan Mohan Dodda, Nureddin Ashammakhi and Rotimi Sadiku