A Novel Delivery System of RGD-HSA Loaded GEM/CUR Nanoparticles for the Treatment of Pancreatic Cancer Therapy

Abstract

Introduction: Pancreatic cancer is one of the most common malignant tumors and is characterized by high malignancy, occult incidence and poor prognosis. Traditional chemotherapy drugs have limited efficacy and strong side effects. Therefore, there is an urgent need for a better treatment of the malignancy.

Methods: The prepared arginine glycine peptide (RGD)-human serum albumin (HSA)-Gemcitabine (GEM)/Curcumin (CUR) nanoparticles (NPs) were characterized for physicochemical properties, stability and in vitro release. Comparisons of HSA-GEM/CUR NPs and RGD-HSA-GEM/CUR NPs regarding tissue distributions and pharmacodynamics were also carried out using mice as the animal models.

Results: Transmission electron micrographs showed that RGD peptide-conjugated HSA-NPs had an irregular surface, good dispersion (PDI=0.139±0.03) and a uniform size distribution (Mean PS=115.6±5.7 nm). The ζ-potential was -17.3 mV. As regards in vitro release, non RGD modified NPs showed a faster release rate in 24 hours, yielding a release amount of 75% for GEM and 72% for CUR. RGD-HSA-GEM/CUR NPs exhibited 67% of accumulated release of GEM (63% for CUR) in 24 hours. This may be due to the HSA chain covering the surface of NPs, which hindered the drug release. The cytotoxicity of GEM/CUR co-loaded NPs was significantly higher than that of single-drug NPs (P < 0.05). In vivo study results indicated that RGD-HSA-GEM/CUR NPs had notable targeting effect on subcutaneous tumors, with a potential to actively deliver drugs to tumor tissues.

Conclusion: In this study, we prepared RGD-HSA-GEM/CUR NPs that had both good water solubility and tumor-targeting property. The results also showed that the RGD modified NPs had advantages in increasing GEM/CUR concentration at tumor sites and reducing its distribution in peripheral organs.

Keywords: Gemcitabine/Curcumin; arginine glycine peptide; human serum albumin; nanoparticles; pancreatic cancer.

Figure 1

Transmission electron microscope of HSA-GEM/CUR NPs (A); RGD-HSA-GEM/CUR NPs (B); RGD-HSA-GEM/CUR NPs after 6 months (C).

Figure 2

The release profile of drug in NPs in PBS (containing 0.1% Tween 80, pH 7.4) (n=6).

Figure 3

Confocal images of cellular uptake of Blank NPs (A); free GEM/CUR (B), HSA-GEM/CUR NPs (C) and RGD-HSA-GEM/CUR NPs (D) by SW1990 cells. Incubation time was 2 hours. (E) was the quantitative results. Bar=50 µm. (^ap <0.05, RGD-HSA-GEM/CUR NPs vs Blank NPs; ^bp <0.05, RGD-HSA-GEM/CUR NPs vs free GEM/CUR, ^cp <0.05, RGD-HSA-GEM/CUR NPs vs HSA-GEM/CUR NPs).

Figure 4

In vitro viability of different NPs formulations in SW1990 cells. Data represents mean ± SD (n = 3). A Cell viability cultured with Blank NPs; free GEM/CUR, HSA-GEM/CUR NPs and RGD-HSA-GEM/CUR NPs at various concentrations of GEM/CUR after 24 h. (^ap <0.05, RGD-HSA-GEM/CUR NPs vs Blank NPs; ^bp <0.05, RGD-HSA-GEM/CUR NPs vs free GEM/CUR, ^cp <0.05, RGD-HSA-GEM/CUR NPs vs HSA-GEM/CUR NPs).

Figure 5

In vivo biodistribution study of modified and non-modified GEM/CUR NPs (n=8). (A) tumor, (B) heart, (C) liver, (D) spleen, (E) lung, (F)kidney and (G) plasma. (^ap <0.05, RGD-HSA-GEM/CUR NPs vs free GEM/CUR, ^bp <0.05, RGD-HSA-GEM/CUR NPs vs HSA-GEM/CUR NPs).

Figure 6

The in vivo imaging of DiR-loaded Blank NPs; free GEM/CUR, HSA-GEM/CUR NPs and RGD-HSA-GEM/CUR NPs in tumor bearing nude mice at 12 h (n=3).

Figure 7

(A) The growth curves of SW1990 tumors in mice. (B) The changes in the body weight of SW1990 tumor-bearing mice. (^ap <0.05, RGD-HSA-GEM/CUR NPs vs Blank NPs; ^bp <0.05, RGD-HSA-GEM/CUR NPs vs free GEM/CUR, ^cp <0.05, RGD-HSA-GEM/CUR NPs vs HSA-GEM/CUR NPs).

Figure 8

Analysis of apoptotic pathway proteins. Western Blot result of apoptotic protein expression (A) and expression of actin (B) on SW1990 cells after incubated with free GEM/CUR, HSA-GEM/CUR NPs and RGD-HSA-GEM/CUR NPs for 24 h (GEM/CUR 0.5 μM). (^ap <0.05, RGD-HSA-GEM/CUR NPs vs Control; ^bp <0.05, RGD-HSA-GEM/CUR NPs vs free GEM/CUR).