Table 1 Physicochemical properties of nanoparticles.

Physicochemical characterization data represent the average of three independent experiments ± SD.

A
FormulationSize (nm)*PDIζ Potential
(mV)
PEG density
(no./100 nm2)§
PEG conformation
[Γ/Γ*]||
mAB density
(no. per particle)
KD (nM)#
PLGA-PEG1%-
ITEM41%
95.4 ± 5.30.14 ± 0.05−4.2 ± 0.39.22.06.13.2
PLGA-PEG5%-
ITEM41%
93.2 ± 7.20.12 ± 0.02−4.6 ± 0.310.32.36.42.4
PLGA-PEG10%-
ITEM40.1%
92.7 ± 5.40.10 ± 0.03−3.4 ± 0.213.42.11.726.5
PLGA-PEG10%-
ITEM41%
94.8 ± 8.70.09 ± 0.04−3.1 ± 0.114.13.26.31.9
PLGA-PEG10%-
ITEM410%
96.4 ± 5.60.12 ± 0.04−5.1 ± 0.413.72.921.82.6
B
FormulationSize (nm)*PDIζ Potential
(mV)
DL (%)**PEG density
(no./100 nm2)§
PEG
conformation
[Γ/Γ*]||
mAB density
(no. per
particle)
MSDwater/
MSDtumor††
PLGA66.9 ± 5.50.16 ± 0.02−4.3 ± 0.45.7 ± 1.2124
PLGA-PEG75.4 ± 5.10.03 ± 0.01−1.4 ± 0.57.7 ± 1.013.02.917
PLGA-PEG-IgG99.7 ± 12.80.18 ± 0.05−4.8 ± 0.48.2 ± 0.619.54.44.2
PLGA-PEG-
ITEM4
94.8 ± 8.70.09 ± 0.04−3.1 ± 0.18.7 ± 0.214.13.26.315
Abraxane143.1 ± 4.60.11 ± 0.01−13.5 ± 1.310

*Hydrodynamic diameter (number mean) measured by dynamic light scattering (DLS).

†PDI indicates the distribution of individual molecular masses in a batch of nanoparticles, measured by DLS.

‡Surface charge measured at 25°C in 15× diluted PBS with ~10 mM NaCl (pH 7.4).

§PEG surface density determined by NMR.

||PEG surface coverage/total surface area [a value <1 indicates mushroom coverage (low density), whereas a value >1 indicates brush regime (high density)].

¶Surface density reported from the LavaPep fluorescent protein assay.

#Equilibrium binding affinity (KD) values determined on a per-nanoparticle basis from fit of Fn14-bindng Biacore data.

**DL is the percentage of PTX encapsulated into nanoparticles (% w/w).

††Ratio indicates the extent to which diffusion of nanoparticles in breast tumor tissues is reduced compared to their diffusion in water.