Liver-specific drug delivery platforms: Applications for the treatment of alcohol-associated liver disease

Table 2 Summary of studies employing a liver-specific drug delivery platform in animal models of alcohol-associated liver disease

Ref.	EtOH feeding model	Platform, route of administration (targeting strategy)	Cargo, paradigm (prevention or treatment)	Physical characterization			Empty particle control	Results	Mechanisms
				Size (nm)	Charge (mV)	EE%			In vitro	In vivo
Liposomes
Ponnappa et al[24], 2005	Rat chronic (8-10 wk), males	Liposomes, i.v. (passive)	S-ODN, prevention	N/P	N/P	10%-14%	Yes	↓ Liver injury (ALT)	-	↓ Serum and liver TNFα
Rodriguez et al[28], 2019	Mouse acute-on-chronic, males	Fusogenic liposomes, i.p. (passive)	Rolipram, treatment	N/P	N/P	N/P	No	↓ Liver injury (ALT and AST); ↓ Steatosis; ↓ Oxidative stress; ↓ ER Stress; ↓ Liver cell apoptosis	-	↑ Hepatic cAMP; ↑ Sod1 and Sod2; ↓ ATF3, Atf4, CHOP, and Gadd34; ↑ Bcl-xl; ↓ Caspase activation
Zhao et al[32], 2016	Mouse chronic (8 wk), males	Liposomes, i.v. (passive)	Puerarin, Prevention	Approximately 182	Approximately -29.4	93.6% ± 1.7%	Yes	↓ Liver injury (ALT and AST)	-	-
Wu et al[35], 2019	Mouse EtOH binge (3 wk), males	Liposomes, i.p. or oral (passive)	Astaxanthin, prevention	225.0 ± 58.3	N/P	98%	Yes	↓ Liver injury (ALT and AST); ↓ Liver fibrosis	-	-
Kumar et al[36], 2019	Rat chronic (4 wk via 2 × daily gavage), males	Liposomes, oral (passive)	Silymarin, treatment	Approximately 146.9	Approximately -47.4	50.50%	No	↓ Liver injury (ALT and AST); ↑ Liver function (albumin); ↓ Oxidative stress; ↓ Liver inflammation	↓ Apoptosis in Chang cells	↑ SOD, GSH, catalase; ↓ TBARS; ↓ IL-6, MPO, nitrite
Yu et al[37], 2021	Mouse acute-on-chronic, males	Liposomes, oral (passive)	Saikosaponin D, prevention	61.66 ± 3.89	-37.18 ± 2.89	92.28% ± 0.84%	Yes	↓ Liver injury (ALT and AST); ↓ Steatosis; ↓ Oxidative stress; ↓ Liver inflammation	-	↓ MDA; ↑ GPx, SOD; ↓ Liver TNFα
Jain et al[38], 2013	Rat chronic (8 wk), males and females	Liposomes, oral (passive)	Mangiferin, prevention	980 ± 230	N/P	N/A	No	↓ Oxidative stress	-	↓ MDA; ↑ SOD, GSH, catalase
Exosomes
Gu et al[50], 2021	Mouse acute-on-chronic, males	Exosomes, from LGG, oral (passive)	Endogenous cargo, treatment	75 ± 12.7	N/P	N/A	N/A	↓ Liver injury (ALT and AST); ↓ Steatosis	↓ TNFα, Il-6, IL-1β, Mcp1 in RAW264.7 cells; ↑ AhR activity in gut leukocytes; ↑ ZO-1, occludin, claudin-1, Nrf2 in Caco-2 cells	↓ Tnf and Il-1β; ↑ Cyp1a1, IL-22, Reg3b, Reg3g; ↓ Hepatic bacteria; ↓ Liver endotoxin; ↑ Nrf2
Zhuang et al[57], 2015	Mouse acute-on-chronic, males	Exosomes from ginger, oral (passive)	Endogenous cargo, prevention	Approximately 340.4	Approximately -27.2	N/P	N/A	↓ Liver injury (ALT and AST); ↓ Steatosis	-	↑ Nrf2 activation
Polymeric nanoparticles
Nag et al[64], 2020	Mouse chronic drinking water (16 wk), males	Poly(lactic-co-glycolic acid) nanoparticles, i.p. (passive)	Tannic acid/ vitamin e, treatment	127.5 ± 1.6	-21.2 ± 0.39	Tannic acid: 69.7% ± 2.6%; Vitamin E: 63.7% ± 3.2%	No	↓ Liver injury (ALT, AST, ALP); ↓ Steatosis; ↓ Liver fibrosis; ↓ Oxidative stress; ↓ Liver cell apoptosis; ↓ Liver inflammation; ↑ Cell survival	-	↑ HDL ↓ LDL; ↓ ROS; ↑ Catalase, GPx, Nrf2; ↓ Bax, bad, cytochrome C, caspase activation; ↑ Bcl2; ↓ TFGβ, IL-6, TNFα, IL-1β, iNOS, COX2; ↓ EGF, EGFR, AKT, PI3K, and mTOR
Natarajan et al[68], 2019	Mouse chronic (4 wk), males	Poly l-lysine-polyethylene glycol copolymer nanoparticles, i.p. (passive)	Superoxide dismutase, treatment	Approximately 44	N/P	N/P	No	↓ Steatosis; ↓ Liver inflammation	↑ SOD1 and ↓ DCF in E47 Hepatoma cells	↓ SREBP1; ↑ ADH1; ↓ Cd68, Ccl2, Mmp12, MCP1, and CCR2; ↑ P-AMPKα
Gopal et al[73], 2020	Mouse chronic (4 wk), males	Poly l-lysine-polyethylene glycol copolymer nanoparticles, i.p. (passive)	Superoxide dismutase 1, treatment	Approximately 44	N/P	N/P	No	↓ Liver injury (ALT); ↓ Steatosis	-	↓ Plasma and liver MCP-1; ↑ Pparα, Acox1, and Acot1; ↑ Mt2; ↑ SOD1 activity
Zhang et al[75], 2022	Mouse chronic (3 wk) + CCL4, females	Chol-PCX nanoparticles, i.v. (passive)	PCX and anti-miR-155, Treatment	Approximately 70	Approximately 25	N/P	No	↓ Liver injury (ALT); ↓ Liver fibrosis; ↓ Liver inflammation	↓ LPS-induced miR-155 expression in RAW264.7 cells; ↑ CXCR4 antagonism in U20S cells	↓ Col1a1, MMPs, TIMPs, HSC activation; ↓ F480+ cells
Wang et al[76], 2020	Mouse EtOH binge (4 d), females	Angelica sinensis amphipathic cholesteryl hemisuccinate conjugate nanoparticles, i.v. (passive)	Curcumin, prevention	Approximately 208.4	Approximately -20	54.7%-86.1%	Yes	↓ Liver injury (ALT and AST); ↓ Oxidative stress	-	↑ GSH; ↓ ROS (DHE and MDA)
Bacteria and viruses
Hendrikx et al[83], 2019	Mouse acute-on-chronic, male and females	L. reuteri, oral (intestine-targeted)	IL-22, prevention	N/A	N/A	N/A	Yes (regular L. reuteri)	↓ Liver injury (ALT); ↓ Steatosis (ORO and TG); ↓ Liver inflammation; ↑ Intestinal barrier defense	-	↓ Cxcl1, Cxcl2; ↑ Small intestine Reg3g; ↓ Hepatic bacteria
Satishchandran et al[93], 2018	Mouse chronic (5 wk), females	AAV8, i.v. (active)	pri-MiR122, treatment	N/A	N/A	N/A	Yes (scrambled miRNA)	↓ Liver injury (ALT); ↓ Steatosis (TG, ORO); ↓ Liver inflammation; ↓ Liver fibrosis (Sirius red)	-	↓ MCP1, IL-1β; ↓ Col1a1

Passive targeting denotes a strategy wherein the physical properties of a particle are modified to target the liver, and active targeting denotes a strategy wherein a particle targets the liver through a ligand/receptor interaction. Treatment paradigm denotes models wherein the drug is administered after liver injury has been established (e.g., half-way through the model, at the end of the model, etc.), whereas prevention paradigm denotes models wherein the drug is administered for the entire duration of the model. Changes in results/mechanisms columns are in liver unless otherwise stated. AAV8: Adeno-associated Virus Serotype 8; ADH1: Alcohol dehydrogenase 1; AhR: Aryl hydrocarbon receptor; AKT: Protein kinase B; ALP: Alkaline phosphatase; ALT: Alanine aminotransferase; AST: Aspartate aminotransferase; ATF3: Activating transcription factor 3; cAMP: Cyclic adenosine monophosphate; CCl4: Carbon tetrachloride; CCR2: C-C motif chemokine receptor 2; CHOP: C/EBP homologous protein; COX2: Cyclooxygenase 2; DCF: Dichlorodihydrofluorescein; DHE: Dihydroethidium; EE%: Encapsulation efficiency percent; EGF: Epidermal growth factor; EGFR: Epidermal growth factor receptor; ER: Endoplasmic reticulum; GPx: Glutathione peroxidase; GSH: Glutathione; HDL: High density lipoprotein; HSC: Hepatic stellate cell; i.p.: Intraperitoneal injection; i.v.: Intravenous injection; IL: Interleukin ; iNOS: Inducible nitric oxide synthase; LDL: Low density lipoprotein; LGG: Lactobacillus rhamnosus GG; LPS: Lipopolysaccharide; MCP1: Monocyte chemoattractant protein 1; MDA: Malondialdehyde; miR: Micro-RNA; MMPs: Matrix metalloproteinases; MPO: Myeloperoxidase; mTOR: Mechanistic target of rapamycin; N/A: Not applicable; N/P: Not provided; NRF2: Nuclear factor erythroid 2-related factor 2; ORO: Oil red O; P-AMPKα: Phospho-AMP-activated protein kinase alpha; PCX: Polycationic CXCR4 antagonists; PEG: Polyethylene glycol; PG: Propylene glycol; PI3K: Phosphoinositide 3-kinase; RoA: Route of administration; ROS: Reactive oxygen species; SOD: Superoxide dismutase; S-ODN: Antisense phosphorothioate oligodeoxynucleotide; TBARS: Thiobarbituric acid reactive substances; TG: Triglycerides; TGFβ: Transforming growth factor beta; TIMPs: Tissue inhibitors of metalloproteinases; TNFα: Tumor necrosis factor alpha; ZO1: Zonal occludin 1.