Table 1.

Highlights of emerging biomaterial-based strategies for immunoengineering in arthritis.

	Biomaterial	Immunoengineering strategy	Cellular Target	Model	Reference
Synthetic
	Poly (lactic-co-glycolic acid)	Microsphere; triamcinolone acetonide	Macrophage	OA, clinical	[62]
	(Poly)glycolic (PEG)	Nanoparticle; release of TNF-α or IL-1 blocking antibodies	Fibroblast-like synoviocytes	RA, in vitro	[63]
		Nanoparticle, paclitaxel	No specific target	In vitro, rats	[64]
		Scaffold; delivery of bound IL-4	Macrophage	RA, mouse	[65]
		Hydrogel; dexamethasone	Cartilage, osteophyte	PTOA, mouse	[66]
	PEG-PCL	Nanoparticle; release of Methotrexate	Synovial macrophages	RA, rats	[67]
Natural
	Chitosan	Scaffold	Neutrophils and macrophages	OA, rabbit; OA, clinical	[68, 69]
		Nanosphere; kartogenin and diclofenac	Chondrocytes and macrophage	OA, rats	[70]
	Elastin-like polypeptides	Biopolymer; non-aggregating and aggregating ELP	Whole joint	Knee (OA), rat	[71]
		Biopolymer, sTNFRII or -IL1Ra	Fibrochondrocytes, thymocytes, and lymphocytes	Intervertebral disc, in vitro	[72]
		Biopolymer; loaded with IL-1Ra or sTNFRII	Whole joint	PTA (articular fracture), mouse	[37]
	Type II collagen	Scaffold; squid type II collagen	Macrophage	OA, rat	[73]
	Albumin/ melittin	Nanoparticle; delivery of siRNA for NF-κB inhibition	Innate and adaptive immune cells	RA and PTOA, in vivo	[74–77]
	Lipids	Nanoparticle; delivery of siRNA for Indian Hedgehog	Whole joint	OA, rat	[78]
	Agarose	Hydrogel	Monocyte	OA	[79]
	Silk fibroin	Scaffold	MSC/T cell	OA, rabbit	[80]
	Hyaluronic acid/silk fibroin	Hydrogel; vanillic acid or epimedin C	Chondrocytes	Cartilage engineering	[81]
Combined
	Heparan/PEG	Microparticles; tumor necrosis factor-alpha stimulated gene-6	Leukocytes, neutrophils, macrophages, MSCs	In vitro; OA, rat	[82]
	Gellan gum/silk fibroin	Hydrogel; betamethasone	Chondrocyte	RA, in vitro	[83]