Table 2.

Few examples of therapeutic nanoparticles/microparticles that have experimentally (in vitro, in vivo, and ex vivo conditions) used in the treatment of IBD.

Nanoparticles	Therapeutic Agent	Characteristics
Cationic Polymethacrylate (Eudragit RL) NPs	Clodronate	Decreased MPO activity in TNBS- and OXA-induced-colitis compared to free clodronate [175]
Polymeric (poly 1,4-phenyl acetone dimethylene-thioketal) NPs complexed with DOTAP	TNF-$\alpha$ small interfering ribonucleic acid (siRNA)	Thioketal NPs degrade in response to ROS, and DOTAP enhances mucosal transport. Protects UC by decreasing TNF-$\alpha$ level [182]
Nitroxide-radical NPs comprising of block copolymer methoxy-poly(ethylene glycol)-b-poly(4-(2,26,6-tetramethyl-piperidine-1-oxyl)oxymethylstyrene (MeO-PEG-b-PMOT)	TEMPOL	Reduction in colitis with successful scavenging of ROS [183]
Poly(lactic-co-glycolic acid) (PLGA) NPs encapsulated inside Eudragit P4135F microspheres	Tacrolimus	Provided protection to the drug at acidic pH [189]
PLGA/Eudragit NPs	Budesonide (BSD)	Sustained release of BSD at colonic pH and improved therapeutic effects of BSD against TNBS-induced colitis [192]
PLGA/Eudragit S100 NPs	Curcumin	Reduced TNF-$\alpha$ secretion in LPS-activated macrophages. Reduced neutrophil infiltration in a DSS-colitis model [187]
Pectin coated-chitosan-hydroxide biohybrid beads	5-ASA	Protection to NPs to transport through gastric juices in upper GIT and sustained release of the drugs at 7.4 [193]
PLGA-coated Eudragit S100 nanospheres	Cyclosporine	Sustained release at 7.4 and used in UC therapy [194]
Eudragit S100/ethyl cellulose nanofibers	Budesonide (BSD)	Sustained release of drug at a pH of 7.4 [195]
Chitosan and alginate coated with Eudragit S100 microcrystals	Dexamethasone	Release of drug in colonic pH and alleviate inflammation in DSS-colitis model [197]
Chitosan and alginate hydrogel/PLA NPs	Anti-inflammatory tripeptide Lys–Pro–Val (KPV)	Reduced MPO activity and colitis symptoms [202]
Cross-linked pectin microspheres	Indomethacin	Increased colon-specific delivery at a pH of 7.4 [206]
Calcium pectin–silica gel beads	Mesalazine	Controlled release of mesalazine at the simulated upper GIT condition and increased mesalazine release in the simulated colonic fluid [207]
Grapefruit-derived nanovesicles	Methotrexate	Downregulation of IL-1$\beta$ and TNF-$\alpha$ by upregulating release of heme-oxygenase I and induced anti-inflammatory properties against DSS-IBD [211]
Ginger-derived NPs	Ginger	Elevated anti-inflammatory cytokines and downregulated concertation’s of pro-inflammatory cytokines TNF-$\alpha$, IL-1$\beta$, and IL-6 [212]
PEI NPs	Anti-cluster of differentiation (CD)98 siRNA	Reduction of CD98 expression in DSS-induced colitis [215]
Mannosylated bio-reducible cationic polymeric NPs	TNF-$\alpha$ siRNA	Reduction in TNF-$\alpha$ expression in DSS-induced colitis [218]
Galactosylated trimethyl chitosan cysteine NPs	Mitogen-Activated Protein Kinase Kinase Kinase Kinase (Map4k4) siRNA	Blocks the TNF-$\alpha$ production in DSS-induced UC [219]
Peanut and wheat germ-lecithin decorated NPs	Betamethasone	Specificity towards inflamed tissues having high expression of lecithin [222]
PLA-PEG (poly (lactic acid) poly (ethylene glycol) block copolymer) grafted with the Fab’ portion of F4/F80 Ab	TNF-$\alpha$	Enhanced macrophage-targeting and endocytosis of NPs. Oral administration led to attention in DSS-induced colitis [229]
Folic acid-conjugated PLGA NPs	Resveratrol	Oral delivery reduced colitis in TNBS-induced rat model [223]
Chitosan microparticle	Quercetin	Oral administration reduced colitis in an acetic acid-induced rabbit model compared to free quercetin [210]

Abbreviations used: MPO: myeloperoxidase; TNBS: 2,4,6-trinitrobenzene sulfonic acid; OXA: oxazolone; DOTAP: 1,2-dioleoyl-3-trimethylammonium-propan; TNF-$\alpha$: tumor necrosis factor; IL: interleukins; ROS: reactive oxygen species; UC: ulcerative colitis; TEMPOL: 4-hydroxy-2,2,6,6-tetramethylpiperidin-1-oxyl; LPS: lipopolysaccharide; DSS: dextran sulfate sodium; 5-ASA: aminosalicylic acid; GIT: gastrointestinal tract; NP: nanoparticle; PEI: polyethyleneimine.