Nanoparticle-based systems for liver therapy: Overcoming fibrosis and enhancing drug efficacy

Table 2 Overview of drug delivery nanoparticles, including representative surface ligands, typical drug-payload capacity, and predominant internalization mechanisms

Nanoparticle	Representative surface ligands	Typical drug-payload capacity	Predominant cellular internalization pathway
Gold nanoparticles	PEG, folic-acid, RGD peptide, anti-HER2 Ab	5-10 wt% (approximately 80-150 doxorubicin molecules per 20 nm gold NP)	Receptor-mediated clathrin-dependent endocytosis
Silica nanoparticles	PEG, folic-acid, iRGD peptide	25-30 wt% (paclitaxel approximately 250 mg/g MSNP)4	Clathrin-mediated endocytosis; caveolae contribution reported
Carbon nanotubes	PEG, transferrin, RGD peptide	approximately 20 wt% (doxorubicin 2.5 mg/mg carbon nanotube)	Energy-dependent endocytosis and direct membrane penetration
Fullerenes (C60 derivatives)	PEG-C60, malonic-acid-C60, amino-C60	5-15 wt% for hydrophobic drugs	Caveolae-mediated endocytosis and passive diffusion
Liposomes	DSPE-PEG, antibody fragments, folic-acid	10-15 wt% (Doxil® approximately 14 wt% doxorubicin)	Endocytosis/membrane fusion; phagocytosis by macrophages
Solid lipid nanoparticles	PEG, polysorbate 80, lactoferrin	5-12 wt% (curcumin 85 mg/g solid lipid NP)	Clathrin- & caveolae-mediated endocytosis
Polymeric Nanoparticles (PLGA, PLA)	PEG, folic-acid, aptamers, anti-EGFR Ab	5-20 wt% (paclitaxel 120 mg/g PLGA NP)	Receptor-mediated endocytosis (clathrin & caveolae)
Nanomicelles	PEG-PLA or PEG-PCL cores with folate or RGD	10-30 wt% hydrophobics (docetaxel 250 mg/g)	Clathrin-mediated endocytosis; macropinocytosis

AB: Antibody; DSPE: 1,2-Distearoyl-sn-glycero-3-phosphoethanolamine; EGFR: Epidermal growth factor receptor; HER2: Human epidermal growth factor receptor 2; iRGD: Integrin RGD; MSNP: Mesoporous silica nanoparticle; NP: Nanoparticle; PCL: Polycaprolactone; PEG: Polyethylene glycol; PLA: Polylactic acid; RGD; Arginine-glycine-aspartic acid; wt%: Weight percentage.