Supramolecular nanoparticles generated by the self-assembly of polyrotaxanes for antitumor drug delivery

Figures & data

Figure 1 The ¹H NMR spectra of cinnamic-acid-modified PEG (A), α-CD (B), and polyrotaxanes (C).

Abbreviations: PEG, poly(ethylene glycol); α-CD, α-cyclodextrin.

Figure 2 The XRD spectra of α-cyclodextrin (A), cinnamic-acid-modified PEG (B), and polyrotaxane (C).

Abbreviations: XRD, X-ray diffractometry; PEG, poly(ethylene glycol).

Figure 3 Size distributions and morphologies of blank and drug-loaded polyrotaxane nanoparticles. (A) DLS of blank nanoparticles; (B) DLS of drug-loaded nanoparticles; (C) TEM photograph of blank nanoparticles; (D) AFM image of blank nanoparticles; (E) TEM photograph of drug-loaded nanoparticles; (F) AFM image of drug-loaded nanoparticles.

Abbreviations: DLS, dynamic light scattering; TEM, transmission electron microscopy; AFM, atomic force microscopy.

Figure 4 The illustrated formation of drug-loaded polyrotaxane nanoparticles.

Abbreviations: PEG, poly(ethylene glycol); DOX, doxorubicin.

Table 1 The drug-loading content and encapsulation efficiency of polyrotaxane nanoparticles

Sample	EG/CDa	Mean diameter (nm)		DLC (%)	EE (%)
		Beforeb	Afterc
α-CDs/Cin-PEG	2.8	57 ± 8	107 ± 12	18.4 ± 0.7	78.1

Notes:

a Calculated from ¹H NMR spectrum;

b before drug-loading;

c after drug-loading.

Abbreviations: EG, ethylene glycol; CD, cyclodextrin; DLC, drug-loading content; EE, encapsulation efficiency; α-CDs, α-cyclodextrins; Cin-PEG, cinnamic-acid-modified poly(ethylene glycol).

Figure 5 Release profiles of doxorubicin hydrochloride (A) and drug-loaded polyrotaxane nanoparticles (B).

Figure 6 The cytotoxicity of blank polyrotaxane nanoparticles.

Figure 7 The in vitro inhibition effect of drug-loaded polyrotaxane nanoparticles on 4T1 breast cancer cells.

Note: The concentration of doxorubicin was 10 μg/mL.

Figure 8 Confocal microscopy photographs of doxorubicin and drug-loaded nanoparticles incubated with 4T1 breast cancer cells. (A) doxorubicin hydrochloride and (B) doxorubicin-loaded nanoparticles incubated for 3 hours; (C) doxorubicin hydrochloride and (D) doxorubicin-loaded nanoparticles incubated for 13 hours.

Note: The photographs from left to right (numbered 1 to 4) are the overlapped photos of bright field and doxorubicin stained nuclei.

Figure 9 The in vivo inhibition effect of doxorubicin-loaded polyrotaxane nanoparticles on tumor growth in mice via venous injection.

Figure 10 The inhibition rate of drug-loaded nanoparticles to breast cancer in mouse models.

Figure 11 Histological photographs of mice cardiac muscles administrated with doxorubicin hydrochloride (A) and drug-loaded polyrotaxane nanoparticles (B).

Note: The arrows show the inflammation.