Fluorine-modified polymers reduce the adsorption of immune-reactive proteins to PEGylated gold nanoparticles

Figures & data

Figure 1. Characterization of polymer-coated gold nanoparticles.

(A) Synthesis of polymers and surface grafting of gold nanoparticles by fluorine polymers. (B) Transmission electron microscopy and histography of polymer-coated gold nanoparticles. (C) UV-VIS of polymer-coated gold nanoparticles from 400 to 800 nm. (D) Interfacial tension of polymer-coated gold nanoparticles at the water–air interface. ****p ≤ 0.0001; one-way analysis of variance, Dunnett's multiple comparisons test.

AuNP: Gold nanoparticle; FNP: Fluoro–gold nanoparticle; IFT: Interfacial tension; RAFT: Reversible addition fragmentation chain transfer.

Table 1. Experimental conditions and molecular weights of polymer, determined by gel permeation chromatography.

Polymers	Degrees of polymerization	Conversion	Fluorine content	Mn:GPC (kDa)^a	Mw:GPC (kDa)^a	Đ^a
Poly(OEGA)40	40	99%	0%	14.3	17.3	1.21
PFPE-Poly(OEGA)80	80	99%	3%	28.9	34.7	1.20
PFPE-Poly(OEGA)40	40	97%	6%	12.0	14.2	1.18
PFPE-Poly(OEGA)16	16	98%	15%	7.6	8.4	1.11
PFPE-Poly(OEGA)6	6	94%	30%	5.0	5.3	1.06

GPC: Gel permeation chromatography; OEGA: Oligo(ethylene glycol) methyl ether acrylate; PFPE: Perfluoropolyether.

Figure 2. Chemical synthesis of gold nanoparticles using the Turkevich method.

AuNP: Gold nanoparticle; FNP: Fluoro–gold nanoparticle.

Figure 3. Colloidal stability of fluoro–gold nanoparticles.

(A–C) Hydrodynamic size distribution of polymer-coated gold nanoparticles in H₂O, phospahte-buffered saline and DMEM, respectively.

DMEM: Dulbecco's modified eagle medium; FNP: Fluoro–gold nanoparticle; PBS: Phosphate-buffered saline.

Table 2. Hydrodynamic size of polymer-capped nanoparticles in physiologically relevant solutions.

Fluorine%	Hydrodynamic size in H2O	Hydrodynamic size in phosphate-buffered saline	Hydrodynamic size in DMEM
0%	59 nm	268 nm	267 nm
3%	59 nm	44 nm	51 nm
6%	51 nm	38 nm	32 nm
15%	43 nm	32 nm	38 nm
30%	32 nm	24 nm	38 nm

DMEM: Dulbecco's modified eagle medium.

Figure 4. Cytotoxicity of polymer-coated gold nanoparticles.

Cytotoxicity of polymer-coated gold nanoparticles on (A) CHO-A5, (B) HEK-293 and (C) MDA-MB-231 cell lines after 24 h incubation, n = 3 independent experiments.

FNP: Fluoro–gold nanoparticle.

Figure 5. Cellular uptake of polymer-coated gold nanoparticles.

(A) Dark field imaging of RAW 264.7 cells incubated with polymer-coated nanoparticles in OptiMem; red represents the gold content in cells (scale bar: 50 μm). (B) Quantitative analysis of polymer-coated nanoparticle uptake on RAW 264.7 cells using inductively coupled plasma optical emission spectroscopy. ****p ≤ 0.0001; ordinary one-way analysis of variance, Dunnett's multiple comparisons test, n = 3 independent experiments.

FNP: Fluoro–gold nanoparticle.

Figure 6. Protein adsorption determined by proteomic analysis.

(A) Heat map for protein absorption. (B) Complement protein absorption compared with 0% fluorine. ***p ≤ 0.001; ****p ≤ 0.0001; ordinary one-way analysis of variance (ANOVA), Dunnett's multiple comparisons test. (C) Ig protein absorption compared with 0% fluorine. *p ≤ 0.05; **p ≤ 0.01; ****p ≤ 0.0001; ordinary one-way ANOVA, Tukey's multiple comparisons test. (D) Platelet basic protein absorption compared with 0% fluorine. (E) Apolipoprotein absorption compared with 0% fluorine. ****p ≤ 0.0001; ordinary one-way ANOVA, Dunnett's multiple comparisons test. (F & G) CD209 and calreticulin absorption compared with 0% fluorine, respectively.*p ≤ 0.05; one sample t-test.

Ctrl: Control; FNP: Fluoro–gold nanoparticle.