Hydrogels, a type of hydrophilic three-dimensional crosslinking network, have shown the potential to repair injured tissue, as they provide a scaffold for cell attachment, differentiation, and proliferation. However, the low mechanical strength and limited functions of traditional hydrogels have greatly limited their application in tissue engineering.

Nanocomposite strategies promise to enhance the stiffness and regulate the viscoelasticity of hydrogels via nanoparticle-polymer interactions. Moreover, nanoparticles can endow the hydrogel with new properties, such as electrical conductivity, antibacterial effects, antioxidation, and magnetic responsiveness, extending their use to broader applications. In addition, therapeutic drugs can be released more smartly from nanocomposite hydrogels when they are encapsulated in or linked to stimuli-responsive nanoparticles, which increases the precision of the control of tissue repair.

This Special Issue, therefore, aims to create more approaches by using different nanoparticles in hydrogel fabrication and to further understand the importance of nanocomposite strategies for hydrogels in tissue engineering. We invite global authors working on nanocomposite hydrogels to share their experience, and both original research and review articles are welcome.

Potential topics include but are not limited to the following:

• Mechanisms of the interactions between different nanoparticles and polymers
• Viscoelastic nanocomposite hydrogels for three-dimensional bioprinting
• Effects of alterations in the viscoelasticity of nanocomposite hydrogels on cell behavior
• Emerging functions of nanocomposite hydrogels, including such as electrical conductivity, antibacterial and antioxidation effects, and magnetic responsiveness for biomedical applications
• Nanoparticle cargos in hydrogels for the smart release of drugs in response to light, heat, or pH