Anticancer Efficacy of Photodynamic Therapy with Lung Cancer-Targeted Nanoparticles

Summary

Photodynamic therapy (PDT) is an alternative choice for lung cancer treatment. To increase the therapeutic effect of PDT, lung cancer-targeted nanoparticles combined with chemotherapy were developed. Both in vitro and in vivo anticancer efficacies of PDT with prepared nanoparticles were evaluated.

Abstract

Photodynamic therapy (PDT) is a non-invasive and non-surgical method representing an attractive alternative choice for lung cancer treatment. Photosensitizers selectively accumulate in tumor tissue and lead to tumor cell death in the presence of oxygen and the proper wavelength of light.

To increase the therapeutic effect of PDT, we developed both photosensitizer- and anticancer agent-loaded lung cancer-targeted nanoparticles. Both enhanced permeability and retention (EPR) effect-based passive targeting and hyaluronic-acid-CD44 interaction-based active targeting were applied. CD44 is a well-known hyaluronic acid receptor that is often introduced as a biomarker of non-small cell lung cancer.

In addition, a combination of PDT and chemotherapy is adopted in the present study. This combination concept may increase anticancer therapeutic effects and reduce adverse reactions.

We chose hypocrellin B (HB) as a novel photosensitizer in this study. It has been reported that HB causes higher anticancer efficacy of PDT compared to hematoporphyrin derivatives¹. Paclitaxel was selected as the anticancer drug since it has proven to be a potential treatment for lung cancer².

The antitumor efficacies of photosensitizer (HB) solution, photosensitizer encapsulated hyaluronic acid-ceramide nanoparticles (HB-NPs), and both photosensitizer- and anticancer agent (paclitaxel)-encapsulated hyaluronic acid-ceramide nanoparticles (HB-P-NPs) after PDT were compared both in vitro and in vivo. The in vitro phototoxicity in A549 (human lung adenocarcinoma) cells and the in vivo antitumor efficacy in A549 tumor-bearing mice were evaluated.

The HB-P-NP treatment group showed the most effective anticancer effect after PDT. In conclusion, the HB-P-NPs prepared in the present study represent a potential and novel photosensitizer delivery system in treating lung cancer with PDT.

Introduction

Photodynamic therapy (PDT) is composed of three major factors: photosensitizers, light, and oxygen. PDT is reported as a promising treatment for various cancers³. When the photosensitizers are administered into the cancer patient, they selectively accumulate in the tumor tissues. When the proper wavelength of light is applied, the highly reactive singlet oxygen and other free radicals lead to tumor cell damage⁴.

Lung cancer was introduced as one of the first applications for PDT in the early 1980s⁵. PDT provides several advantages in treating lung cancer. Since PDT is a non-invasive and non-surgical treatme....

Protocol

NOTE: All animal study protocols were approved by the Institutional Animal Care and Use Committee of Seoul National University Bundang Hospital (BA1308-134/072-01).

1. Synthesis of Hyaluronic Acid-Ceramide (HACE)

1. Solubilize 12.21 mmol of hyaluronic acid (HA) oligomer and 9.77 mmol of tetra-n-butylammonium hydroxide (TBA) in 60 ml of double-distilled water (DDW). Stir for 30 min.
2. To synthesize the DS-Y30 linker, dissolve 8.59 mmol of DS-Y30 ceramide and 9.45 mmol of triethylamine in 25 ml of tetrahydrofuran (THF). Mix with 8.59 mmol of 4-chloromethylbenzoyl chloride in THF. Stir for 6 hr at 60 °C.
3. Dissolve the synthe....

Results

We prepared both HB-NPs and HB-P-NPs with the techniques mentioned above. The mean diameters of HB-NPs and HB-P-NPs were 220.9 ± 3.2 nm and 211.9 ± 1.6 nm, respectively.

The cell viability of A549 cells after 4 hr of incubation with PBS, empty NPs, HB-NPs, and HB-P-NPs followed by light irradiation (0 to 16 J/cm²) is shown in Figure 1. Without light, the HB-NP treatment group showed no cytotoxicity at.......

Discussion

The most critical step in this study is selecting the proper laser conditions: wavelength, power, and irradiation time. The proper wavelength of light suitable for the specific photosensitizer is necessary for the PDT. We used a 630-nm laser that was appropriate for hypocrellin B. The output power was another important factor, which was set at 400 mW/cm² based on many pilot studies. Output powers exceeding 400 mW/cm² damaged the cells or the skin surface of the animals due to the irradiation itself,.......

Materials

List of materials used in this article

Name	Company	Catalog Number	Comments
oligo hyaluronic acid	Bioland Co., Ltd.	_
DS-Y30 (ceramide 3B; mainly N-oleoyl-phytosphingosine)	Doosan Biotech Co., Ltd.	_
adipic acid dihydrazide	Sigma Aldrich	A0638
N-(3-dimethylaminopropyl)-N′-ethylcarbodiimide	Sigma Aldrich	39391
4-(chloromethyl)benzoyl chloride	Sigma Aldrich	270784
Tween 80	Tokyo Chemical Industry Co., Ltd.	T0546
syringe filter	Sartorius Stedim Biotech GmbH	17762	15 mm, RC, PP, 0.45 µm
triethylamine	Sigma Aldrich	T0886
Mini-GeBAflex tubes	Gene Bio-Application Ltd.	D070-12-100
Paclitaxel	Taihua Corporations	_
RPMI-1640	Gibco Life Technologies, Inc.	11875
Penicillin–streptomycin	Gibco Life Technologies, Inc.	15070
Fetal bovine serum	Gibco Life Technologies, Inc.	16140071
Celite (Filter agent)	Sigma Aldrich	6858	See step 1.4