Highlights the characteristics and applications of nanocomposite hydrogels based on the type of their nanoparticles: carbon-based, polymeric-based, inorganic-based, and metallic-based hydrogels.

Category	Nanoparticle types	Characteristics	Applications
Carbon-based nanocomposite hydrogels	Carbon nanotubes (CNTs), graphene, graphene oxide	Exceptional mechanical, electrical, and thermal properties	Tissue engineering scaffolds
		Improved strength, conductivity, and thermal stability	Flexible electronics sensors
Polymeric-based nanocomposite hydrogels	Nanofibers, micelles, dendrimers	Structural support, enhanced drug encapsulation, regulated release kinetics	Drug delivery
			Wound healing
			Tissue regeneration
Inorganic-based nanocomposite hydrogels	Silica nanoparticles, hydroxyapatite, metal oxides	Modulated mechanical strength, improved bioactivity, controlled ion release	Bone tissue engineering
			Dental materials
			Controlled drug delivery
			Antimicrobial agent
Metallic-based nanocomposite hydrogels	Gold nanoparticles, silver nanoparticles	Distinct optical, antimicrobial, photothermal, and catalytic properties	Wound dressings
		Enhanced antimicrobial activity, localized drug release	Cancer therapy
			Antibacterial applications