TABLE 1.

Summary of the research work of nanotechnology in the treatment of osteoarthritis.

	NPs	Advantages	Example	References
Drug delivery system	Chitosan	Rich in amino groups	Chitosan	Kang et al. (2014)
		Promote cartilage formation	Polycationic chitosan
	Aliphatic polyesters	Biocompatibility and biodegradability	Polylactic acid	Salama et al. (2020)
			Polyglycolide
	Targeting NPs	Active targeting	HA-NPs	Kang et al. (2021), Rey-Rico et al. (2017), Geiger et al. (2018)
		Resistance to hyaluronidase digestion	IL-1RA
			Dendrimers
	Stimulate reactive NPs	Heat response	Hollow dextran/poly (N-isopropylacrylamide) NPs	Song et al. (2021), Lachowicz et al. (2020), Deloney et al. (2020), Kang et al. (2016), Zhao Y. et al. (2019)
		Large drug load	Chitosan-modified molybdenum disulfide nanosheets
		Double release	pNIPAm
		Vitro control
	Micelles and liposomes	Amphiphilic	Hydrogen peroxide-sensitive nanomicelle	Wu et al. (2021), Lan et al. (2020); Bhatia et al. (2020)
		Good plasticity	Liposomal gel
Gene delivery system	Exosomes	Penetrate and target cartilage	Exosomes derived from synovial mesenchymal stem cells	Tao et al. (2021)
	Cytolytic peptide	The pore-forming ability is reduced, and the ability to insert bilayer film is retained	Modified peptide	Yan et al. (2020)
	siNP-μPLs	Long-term retention	siMMP13-μPLs	Bedingfield et al. (2021)
	Yeast cell wall particle	Oral administration	Yeast cell wall particle-mediated nanotube-RNA delivery system	Zhang et al. (2020)
Scaffold	Bionic scaffold	Good mechanical property and biocompatibility	HA cross-linked three-dimensional scaffold	Wei and Dai, (2021)
	Nanofiber scaffolds	simulate the extracellular matrix	Chitosan/polyvinyl alcohol nanofiber scaffolds	Nour-Eldeen et al. (2020)
Lubricant	Additive NPs	Improve the lubricating property of the lubricant	GNP	Omrani et al. (2021)
	Nanoscale polymer particle	High-water solubility	Mega HPG	Anilkumar et al. (2020)
		Low intrinsic viscosity
		Compactness
		Specific viscosity and hydration