A Modular Coassembly Approach to All-In-One Multifunctional Nanoplatform for Synergistic Codelivery of Doxorubicin and Curcumin

Abstract

Synergistic combination therapy by integrating chemotherapeutics and chemosensitizers into nanoparticles has demonstrated great potential to reduce side effects, overcome multidrug resistance (MDR), and thus improve therapeutic efficacy. However, with regard to the nanocarriers for multidrug codelivery, it remains a strong challenge to maintain design simplicity, while incorporating the desirable multifunctionalities, such as coloaded high payloads, targeted delivery, hemodynamic stability, and also to ensure low drug leakage before reaching the tumor site, but simultaneously the corelease of drugs in the same cancer cell. Herein, we developed a facile modular coassembly approach to construct an all-in-one multifunctional multidrug delivery system for the synergistic codelivery of doxorubicin (DOX, chemotherapeutic agent) and curcumin (CUR, MDR modulator). The acid-cleavable PEGylated polymeric prodrug (DOX-h-PCEC), tumor cell-specific targeting peptide (CRGDK-PEG-PCL), and natural chemosensitizer (CUR) were ratiometrically assembled into in one single nanocarrier (CUR/DOX-h-PCEC@CRGDK NPs). The resulting CUR/DOX-h-PCEC@CRGDK NPs exhibited several desirable characteristics, such as efficient and ratiometric drug loading, high hemodynamic stability and low drug leakage, tumor intracellular acid-triggered cleavage, and subsequent intracellular simultaneous drug corelease, which are expected to maximize a synergistic effect of chemotherapy and chemosensitization. Collectively, the multifunctional nanocarrier is feasible for the creation of a robust nanoplatform for targeted multidrug codelivery and efficient MDR modulation.

Keywords: biocompatibility; modular coassemble; polymeric prodrug; stimulisensitive release; synergistic codelivery.

Scheme 1

Schematic illustrations of the modular coassembly to construct an all-in-one multifunctional multidrug delivery system (curcumin (CUR)/ acid-cleavable PEGylated polymeric prodrug (DOX-h-PCEC) @Cys−Arg−Gly−Asp−Lys (CRGDK) nanoparticles (NPs)) with the capability of efficient encapsulation, targeted delivery, and intracellular controlled corelease.

Scheme 2

Synthetic route of DOX-h-PCEC.

Figure 1

Characterization of DOX-h-PCEC. (A) ¹HNMR spectra of PCEC in CDCl₃ (I), NPC-activated PCEC in CDCl₃ (II), Hydrazide-functionalized PCEC in CDCl₃ (III) and DOX-h-PCEC in DMSO-d₆ (IV); (B) UV spectra of PCEC (0.3 mg/mL), DOX (50 μg/mL), and DOX-h-PCEC (0.3 mg/mL) in DMSO.

Figure 2

Characterization of CRGDK-PEG-PCL. (A) ¹HNMR spectra of Mal-PEG (I), Mal-PEG-PCL (II) and CRGDK-PEG-PCL (III) in DMSO-d₆; (B) gel permeation chromatography (GPC) curves of Mal-PEG-PCL and CRGDK-PEG-PCL in DMF.

Figure 3

Characterizations of CUR/DOX-h-PCEC@CRGDK NPs. (A) TEM image; (B) size histogram; (C) Zeta potential at pH 7.4; (D) Hemodynamic stability in pH 7.4 PBS containing 5% BSA at 37 °C; (E) Size changes of NPs incubated in PBS of pH 7.4 and pH 5.0; (F) CUR leakage from CUR/DOX-h-PCEC@CRGDK NPs (solid line) and CUR loaded CRGDK-PEG-PCL NPs (dashed line) incubated in PBS of pH 7.4 and pH 5.0 containing 10% methanol as solubilizer; The leaked CUR samples were diluted 10 times by same incubation solution.

Figure 4

In vitro drug release profiles. (A) DOX release from CUR/DOX coloaded PCEC NPs; (B) DOX release from CUR/DOX-h-PCEC@CRGDK NPs; (C) CUR release from CUR/DOX coloaded PCEC NPs; (D) CUR release from CUR/DOX-h-PCEC@CRGDK NPs;.

Figure 5

Selective cellular uptake. (A) Representative fluorescence microscopy images of Neuropilin-1 overexpressed human umbilical vein endothelial cells (HUVEC) cells incubated with free DOX, DOX-h-PCEC NPs, and CUR/DOX-h-PCEC@CRGDK NPs at equivalent DOX concentration of 10 μg/mL for 4 h; (B) Average gray value as a criterion to compare the red fluorescent intensity in different images.

Figure 6

Intracellular synergistic corelease and cytotoxicity. (A) Representative fluorescence microscopy images of Adriamycin resistant MCF-7/ADR cells with free DOX, free CUR, physical mixture of DOX and CUR (1.0:1.0, w/w), and CUR/DOX-h-PCEC@CRGDK NPs at equivalent DOX concentration of 10 μg/mL for 4 h; (B) Cytotoxicity of free DOX, physical mixture of DOX and CUR (1.0:1.0, w/w), and CUR/DOX-h-PCEC@CRGDK NPs to MCF-7/ADR cells.