PRHs	pH-responsive hydrogels
MNs	Stainless steel microneedles
ROS	Reactive oxygen species
DEX	Dexamethasone
PEG	Poly(ethylene glycol)
SEM	Scanning electron microscopy
Ti	Titanium
IB	Ibuprofen
MSNs	Mesoporous silica nanoparticles
TRHs	Temperature-responsive hydrogels
LCST	Lower critical solution temperature
UCST	Upper critical solution temperature
PDEAM	Poly(N,N-diethyl acrylamide)
PNIPAM	Poly (N-isopropylacrylamide)
PMVE	Poly(methylvinylether)
PVC	Poly(N-vinylcaprolactam)
β-CD	β-cyclodextrin
Ad-PEG	Adamantyl-terminated poly(ethylene glycol)
α-CD	α-cyclodextrin
DOX	Doxorubicin
HMPC	Hydroxypropyl methylcellulose
CS	Chitosan
Gly	Glycerin
CGHH	Hydroxypropyl methylcellulose/Chitosan/Glycerin composite
NT	Nanotube
BMP	Bone morphogenetic protein
G′	Storage modulus
G″	Loss modulus
ERHs	Electrically responsive hydrogels
CP	Chitosan-graft-polyaniline
OD	Oxidized dextran
MRHs	Magnetically responsive hydrogels
SPIONs	Superparamagnetic iron oxide nanoparticles
LRHs	Light-responsive hydrogels
NIR	Near-infrared radiation
BPNSs	Black phosphorus nanosheets
GRHs	Glucose-responsive hydrogels
IVDD	Intervertebral disc degeneration
HA	Hyaluronic acid
Met	Metformin
ERHs	Enzyme-responsive hydrogels
HAase	Hyaluronidases
β-GUS	β-glucuronidase
CMS	Chymotrypsin
V8	Glutamyl endonuclease
PDOP	Polydopamine
Ag NPs	Silver nanoparticles
PAH	Polyallylamine hydrochloride
PG	Poly(L-glutamic acid)
LBL	Layer by layer
PAR	Poly(arginine)
VEGFA	Vascular endothelial growth factor A
FDA	Food and Drug Administration
ERC	European Research Council