Electrospray Mediated Localized and Targeted Chemotherapy in a Mouse Model of Lung Cancer

Abstract

Background: An advanced stage, centrally localized invasive tumor is a major cause of sudden death in lung cancer patients. Currently, chemotherapy, radiotherapy, laser ablation, or surgical resection if possible are the available state-of-the-art treatments but none of these guarantee remedy or long-term relief and are often associated with fatal complications. Allowing localized chemotherapy, by direct and confined drug delivery only at the tumor site, could be a promising option for preoperative down staging or palliative therapy. Here we report the localized and targeted application of intra tumor delivery of chemotherapeutics using a novel device based on the principle of electrospray. Methods: C57BL/6J mice were injected with Lewis lung carcinoma cells subcutaneously. After 15 days, the animals were anesthetized and the tumors were exposed by skin incision. Tumors were electrosprayed with 100 µg cisplatin on days 0 and 2, and tumor volumes were measured daily. Animals were sacrificed on day 7 after the first electrospray and tumors were analyzed by immunohistochemistry. Results: In this proof-of-concept study, we report that the tumor volume was reduced by 81.2% (22.46 ± 12.14 mm³) after two electrospray mediated Cisplatin deliveries, while the control tumor growth, at the same time point, increased by 200% (514.30 ± 104.50 mm³). Moreover, tunnel and Caspase-3 positive cells were increased after Cisplatin electrospray compared to other experimental groups of animals. Conclusion: Targeted drug delivery by electrospray is efficient in the subcutaneous mouse model of lung cancer and offers a promising opportunity for further development toward its clinical application.

Keywords: coulomb repulsion; electrospray; localized and targeted therapy; localized tumor treatment; novel cancer treatment.

FIGURE 1

MS/MS spectra obtained by collision-induced dissociation of the triply charged platinated hexadeoxynucleotide precursor ions (m/z 669), which basically show the identical fragment ions and give evidence for adduct formation (= unchanged drug activity). Adduct formation and DNA binding sites by naïve Cisplatin (A) Cisplatin after electrospray (B).

FIGURE 2

Intracellular uptake of Cisplatin; percentage of delivered Cisplatin that entered the cells (A) and amount of intracellular Cisplatin (B) after electrospray mediated Cisplatin delivery in vitro. Data presented as mean ± SEM, p < 0.05*, p < 0.001 **, p < 0.0001 ***.

FIGURE 3

Effect of Cisplatin alone and electrospray Cisplatin delivery on cell viability (A), necrosis (B) and apoptosis (C). Graph showing Flow cytometry gating strategy for Annexin V/PI. Data presented as mean ± SEM, p < 0.05*, p < 0.001**, p < 0.0001***.

FIGURE 4

Gating strategy for annexin V/PI staining for invitro experiment. Control cells (A), Cispatin treatment (B), electrospray only (C), electrospray mediated Cisplatin (D).

FIGURE 5

Tumor volume measured in different experimental groups (A). Tumor volume of the three treated groups for better visualization of data (B).

FIGURE 6

Histological images of caspase 3 staining, and the quantification of caspase 3 positive cells (A). Scale bar 100 µm. Images of tunnel positive cells and quantification of tunnel positive cells (B), scale bar 2,000 µm (entire tumor) and 100 µm for inset images, data is presented as number of cells high power field. Data presented as mean ± SEM, p < 0.05*, p < 0.001**, p < 0.0001 ***.