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Method Article

Photodynamic Therapy with Blended Conducting Polymer/Fullerene Nanoparticle Photosensitizers

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DOI:

10.3791/53038

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October 28th, 2015

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1NanoScience Technology Center, University of Central Florida, 2Department of Chemistry, University of Central Florida, 3Department of Materials Science and Engineering, University of Central Florida, 4CREOL, The College of Optics and Photonics, University of Central Florida

In This Article

Summary

This protocol describes a method for the fabrication of conducting polymer nanoparticles blended with fullerene. These nanoparticles were investigated for their potential use as a next generation photosensitizers for Photodynamic Therapy (PDT).

Abstract

In this article a method for the fabrication and reproducible in-vitro evaluation of conducting polymer nanoparticles blended with fullerene as the next generation photosensitizers for Photodynamic Therapy (PDT) is reported. The nanoparticles are formed by hydrophobic interaction of the semiconducting polymer MEH-PPV (poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene]) with the fullerene PCBM (phenyl-C61-butyric acid methyl ester) in the presence of a non-compatible solvent. MEH-PPV has a high extinction coefficient that leads to high rates of triplet formation, and efficient charge and energy transfer to the fullerene PCBM. The latter processes enhance the efficiency of the PDT system through fullerene assisted triplet and radical formation, and ultrafast deactivation of MEH-PPV excited stated. The results reported here show that this nanoparticle PDT sensitizing system is highly effective and shows unexpected specificity to cancer cell lines.

Introduction

In Photodynamic Therapy (PDT) photosensitizers are administered to target tissue, and upon exposure to light the photosensitizer generates Reactive Oxygen Species (ROS). ROS species such as singlet oxygen and superoxide can induce oxidative stress and subsequent structural damage to cells and tissue1-4. Due to its ease of application this method has been actively investigated and clinical trials have taken place5,6. However, significant issues such as dark toxicity of the sensitizers, patient sensitivity to light (due to non-selective distribution of the sensitizer), and hydrophobicity of the sensitizers (which leads to reduced bioavailability and potential acute toxicity) remain.

Here we report a method for the fabrication and in-vitro evaluation of conducting polymer nanoparticles blended with fullerene as the next generation photosensitizers for PDT. The nanoparticles are formed by self-aggregation of the semiconducting polymer MEH-PPV (poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene]) with the fullerene PCBM (phenyl-C61-butyric acid methyl ester) when these materials dissolved in a compatible solvent are rapidly injected into a non-compatible solvent (Figure 1A). The choice of MEH-PPV as the host polymer is motivated by its high extinction coefficient that leads to high rates of triplet formation, and both efficient and ultrafast charge and energy transfer to the fullerene PCBM7. These properties are ideal for sensitization of singlet oxygen and superoxide formation in PDT.

Fullerene has in fact been applied in PDT in both molecular and nanoparticle form8-13. However, severe cytotoxicity has hampered further development12. Here we show that encapsulating the fullerene in a host matrix of MEH-PPV to yield composite MEH-PPV/PCBM nanoparticles results in a PDT sensitizing material that is not intrinsically cytotoxic, shows specificity towards cancer cells due to nanoparticle size and surface charge, and yields highly effective PDT treatment at low light doses due to the aforementioned photophysical properties.

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Protocol

1. Culturing Cell Lines

  1. Thaw TE 71 (Mouse thymic epithelial cells), MDA-MB-231 (Human breast cancer cells), A549 (Human lung cancer cells) and OVCAR3 (Human ovarian tumor cells) by holding the cryogen vials in warm water for less than 2 min. Add 10 ml DMEM media supplemented with 10% FBS to each cell line and centrifuge for 6 min at 106 x g.
  2. Aspirate the suspension and add 3ml media to the pellet. Mix the cells properly by pipetting several times. Add this cell solution to pre-warmed 7 ml DMEM media supplemented with 10% FBS in T75 flasks and keep the flasks in humidified atmosphere of 95% air/ 5% CO2 at 37 °C. Label this flask as Passage 0.
  3. When the confluency of the cells reaches 80%, harvest the cells by incubating them with 0.05% trypsin for 10 min. Neutralize the trypsin by adding equal amount of media. Centrifuge this solution for 6 min at 106 x g. Remove the suspension and add 3 ml fresh media to it. Mix well and transfer small amount (100 µl) to a culture flask containing 7 ml media. Incubate the culture flask in incubator. Label the flask as Passage 1.
  4. Culture the cell lines until passage 11 or 12.

2. Fabrication of Nanoparticles

  1. Preparation of ~10-6 M (adjusted) undiluted MEH-PPV stock solution
    1. In a vial add 1mg Poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene] (MEH-PPV) with molecular weight (average Mn) 150,000-250,000 g/mol and 3 ml tetrahydrofuran (THF). Stir the mixture for 2 hr while heating at 80 °C on a hot plate.
    2. Filter the above solution in a new vial using a 0.2 µm syringe filter. Label this solution as ‘undiluted MEH-PPV stock solution’. This solution will be involved in nanoparticle preparation after fine tuning of the concentration as described in steps 2.1.3 and 2.1.4.
    3. Add 50 µl of the undiluted MEH-PPV stock solution into 3 ml THF. Label this solution as ‘diluted MEH-PPV stock solution’. Transfer to a 1 cm quartz cuvette and measure the absorbance at 495 nm by UV-vis spectroscopy.
    4. If the absorbance of the diluted MEH-PPV stock solution is higher than 0.17, dilute the undiluted MEH-PPV stock solution by adding more THF 1 ml at a time, and repeat step 2.1.3 until the measured absorbance at 495 nm is in the range 0.13-0.17.
    5. Calculate the molarity of the diluted MEH-PPV stock solution by using Lambert-Beer law as shown below. Here 0.15 absorbance is used as an example for the remainder of the protocol (i.e., adjust all following calculations based on observed absorbance), the MEH-PPV extinction coefficient used is 107 M-1 cm-1 and the path length used is 1 cm.
      A = ε x b x c (Eqn 1)
      (ε - the molar extinction coefficient, A – absorbance, b – path length, c – concentration of the solution)
      0.15 = 107 M-1 cm-1 x 1 cm x c (Eqn 2)
      c = 1.5 x 10-8 M (Eqn 3)
      Use this concentration to find the concentration of the undiluted MEH-PPV stock solution as follows:
      M1V1 = M2V2 (Eqn 4)
      0.15 x 10-7 M x 3050 µl = M2 x 50 µl (Eqn 5)
      M2 = 9.15 x 10-7 M (Eqn 6)
      This is the concentration of the ‘adjusted undiluted MEH-PPV stock solution’.
  2. Calculating mass of MEH-PPV in the adjusted undiluted MEH-PPV stock solution
    1. Calculate the mass of MEH-PPV in 1 ml of the adjusted undiluted stock solution as shown below using the molarity obtained in section 2.1.4 and the molecular weight (Mw) of MEH-PPV, which is 106 g/mol.
      M = n/V (n – no. of moles, V – volume in L) (Eqn 7)
      Thus, the mass of MEH-PPV in 1 ml of adjusted undiluted stock solution is 9.15 x 10-4 g.
  3. Blending PCBM in MEH-PPV
    1. Calculate the mass of Phenyl-C61-butyric acid methyl ester (PCBM) to be added into the stock MEH-PPV solution to make 50 wt% PCBM doped MEH-PPV solution, where 50 wt% PCBM is defined with respect to the mass of MEH-PPV (i.e., half the mass of MEH-PPV). By using the weight of MEH-PPV obtained in section 2.2.
      Mass of PCBM/9.15 x 10-4 g of MEH-PPV x 100% = 50 wt% PCBM (Eqn 8)
      Mass of PCBM = 4.57 x 10-4 g (Eqn 9)
    2. Weigh 1 mg PCBM in a vial and add 500 µl THF. Calculate the concentration of PCBM in this solution using the molecular weight of PCBM as 910.88 g/mol
      Molarity of PCBM solution = 0.001 g/(910.88 g/mol * 500 µl)(Eqn 10)
      Molarity of PCBM solution = 2.19 x 10-9 mol/µl(Eqn 11)
    3. Calculate the volume of PCBM solution needed to add to the adjusted undiluted MEH-PPV stock solution to obtain the 50 wt% PCBM doped MEH-PPV solution in THF by using the molarity calculated in step 2.3.2
      4.57 x 10-4 g of PCBM x 1 mol/910.88 g x 1 µl/2.19 x 10-9 mol = 229 µl (Eqn 12)
      Add 229 µl of the PCBM solution into 1 ml of adjusted undiluted MEH-PPV stock solution and mix well.
  4. Preparation of nanoparticles by reprecipitation method
    1. Transfer 1 ml of the blended MEH-PPV/PCBM solution into the 1 ml syringe with the needle attached to it.
    2. Rapidly inject 1 ml of the blended MEH-PPV/PCBM solution into 4 ml of DI water stirring at 1,200 rpm. Stop stirring immediately after injection. Use these nanoparticles without further processing.

3. Incubation of Cell Lines with Nanoparticles for Imaging

NOTE: All the imaging experiments were completed in 35 mm petri dishes

  1. Uptake of nanoparticles in cell lines
    1. Culture cell lines up to the 12th passage. At the 12th passage culture cells in 35 mm Petri dishes. Adjust concentration of cells added to the 35 mm Petri dishes such that after 24 hr the cells are 40% confluent.
    2. At this stage remove the DMEM media supplemented with 10% FBS from the petri dishes, wash the cells with 1x DPBS twice, and add 100 µl of the nanoparticles suspension into 2 ml DMEM to the Petri dishes.
    3. After 24 hr remove the DMEM/nanoparticles suspension from the petri dishes and wash the cells with 1x DPBS 3 times. Then fix the cells by incubating with 4% paraformaldehyde for 10 min. Wash twice with DPBS. Stain the cells with 300 nM DAPI by incubating with the dye for 2 min. Wash twice with DPBS. Then keep the cells in DPBS for imaging.
  2. Detection of ROS
    1. Culture A549 and OVCAR3 cell lines in Petri dishes, 6 per cell line, as explained in section 3.1.1. Label the Petri dishes as shown in the Table 1.
    2. Add 100 µl of the nanoparticle suspension into 2 ml DMEM to three of the petri dishes as shown in the Table 1 and incubate for 24 hr. For the Petri dishes that will receive light doses, wash the cells after 24 hr and suspend the cells in HBSS (Hank’s Balanced Salt Solution) dye free media.
    3. Warm up the lamp of the solar simulator for 15 min. Place UV filter in front of the lamp to filter out UV light. Calibrate the lamp with a reference solar cell by adjusting the lamp power to obtain 0.5 sun (50 mW/cm2) intensity at the surface of the petri dish. In this particular setup that condition was achieved with 218 W power supplied to the lamp.
    4. Place the petri dishes under the lamp (lid open) for 60 min, which results in a light dosage of 180 J/cm2 as shown in the calculations below:
      50 mW/cm2 x 3,600 sec/1,000 = 180 J/cm2
    5. Remove HBSS and without washing further add 2 ml DMEM media supplemented with 10% FBS to the petri dishes. Incubate the cells for another 2 hr.
    6. For the positive control incubate the cells with 100 µM hydrogen peroxide (H2O2) for 30 min.
    7. Stain the cells in all the petri dishes with a final concentration of 5 µM of the ROS detecting reagent by incubating the cells with the dye for 30 min at 37 °C.
    8. Fix the cells by incubating with 4% paraformaldehyde for 10 min. Wash twice with DPBS. Stain the cells with 300 nM DAPI by incubating with the dye for 2 min. Wash twice with DPBS. Then keep the cells in DPBS for imaging.
  3. Apoptosis and necrosis by PI and annexin V FITC
    1. Culture each cell line in 5 Petri dishes. Three of these Petri dishes will be for experiment while the remaining 2 petri dishes will be control samples. Incubate the 3 Petri dishes for experiment with nanoparticles as explained in section 3.1.2. The control samples are not incubated with nanoparticles.
    2. After 24 hr incubation follow the step 3.2.3.
    3. Place the 3 experimental petri dishes under the lamp (lid open) and remove one at 20 min, one at 40 min and one at 60 min. This yields three samples that were exposed to light doses of 60, 120 and 180 J/cm2, respectively (calculation in section 3.2.4). Next, administer a 180 J/cm2 light dosage to one of the control petri dishes. This is the control with light dose applied in the absence of nanoparticles. Do not apply light dose to the remaining control sample (no nanoparticles and no light dose applied).
    4. Replace the HBSS with DMEM media supplemented with 10% FBS and keep the petri dishes in the incubator for 4 hr.
    5. Stain the cells in the experimental and the control petri dishes with 20 µl of annexin V FITC by incubating the cells with the dye for 15 min. Wash twice with DPBS. Stain the cells with 300 nM DAPI as well as 300 nM PI (propidium iodide) by incubating with the dyes for 2 min. Wash twice with DPBS. Then keep the cells in DPBS for imaging.

4. Intrinsic Cytotoxicity of Nanoparticles

  1. Counting cells and culturing in 96-well plates
    1. Harvest the cells from culture flasks by removing media and washing the cells twice with DPBS followed by incubation of the cells with 0.05% trypsin for 10 min. Add 2 ml DMEM media supplemented with 10% FBS to the resulting cell solution. Mix the solution properly to separate cell clusters into singlets.
    2. Take 100 µl of the cell suspension and add to 900 µl DMEM media supplemented with 10% FBS. Mix well. Place 10 µl of this suspension onto a hemocytometer. Count the cells using the hemocytometer and adjust the concentration of the cell suspension in 4.1.1 to 5 x 104 cells/ml.
    3. Take 5 96-well plates labeled as 0 hr, 24 hr, 48 hr, 72 hr and 96 hr. Add 50 µl of the 5 x 104 cells/ml cell solutions (TE 71 and A549) into the wells as shown in Table 2, thus seeding 2,500 cells/well. Do the same procedure for OVCAR3 and MDA-MB-231 cell lines.
    4. After 24 hr wash the wells with 1x DPBS and add 50 µl of increasing concentrations of nanoparticles into the wells as shown in Table 2. Prepare different nanoparticle concentrations by adding 20, 100, and 180 µl of nanoparticle suspension from 2.4.2 to DMEM to obtain a final volume of 2 ml, which yields nanoparticle concentrations of 0.4 x 10-4 mg/ml, 2.0 x 10-4 mg/ml, and 3.6 x 10-4 mg/ml, respectively. Each cell line has triplicates for each concentration of nanoparticles.
  2. Measuring the cell viability in dark
    1. Add 10 µl MTT to the 0 hr plate immediately after adding nanoparticles. Incubate the plate for 4 hr for formazan crystals to form. Add 50 µl solubilization solution into the wells. Incubate the plate for 6 hr to dissolve the formazan crystals.
    2. Measure the cell viability of the 0 hr plate by recording the absorbance at 570 nm with microplate reader.
    3. For 24 hr plate, wash the cells with 1x DPBS and add 50 µl media in each well after 24 hr incubation with nanoparticles. Add MTT and read the plate as explained in 4.2.1 and 4.2.2.
    4. For 48 hr, 72 hr, and 96 hr plates, wash the cells with 1x DPBS and add 50 µl media into the wells after 24 hr incubation with nanoparticles. Incubate the cells for the remaining time periods.
    5. 4.2.5) Measure the cell viability at the particular time points as explained in 4.2.1 and 4.2.2.
    6. Repeat the complete experiment for 3 times (n = 3)

5. Measuring Cell Viability After PDT

  1. Counting cells and culturing in 96-well plates.
    1. Label a set of 96-well plates as shown in Table 3, both for the TE 71 + A549 plates and OVCAR3 + MDA-MB-231 plates. The layout of the plates will be the same as shown in 4.1.3.
    2. Seed the 96-well plates as explained in section 4.1 with the same layout as shown in Table 2 in section 4.1.2.
    3. After 24 hr add nanoparticles to the plates as explained in 4.1.4.
    4. 24 hr after addition of nanoparticles wash the cells with 1x DPBS and add 50 µl HBSS to each well.
    5. Irradiate the plates with the respective light doses as explained in 3.2.3.
    6. Replace the HBSS with 50 µl DMEM media supplemented with 10% FBS and incubate the plates for the respective time periods after PDT.
    7. After each time period measure the cell viability as explained in 4.2.1 and 4.2.2.

6. Fluorescence Microscopy

  1. Uptake of nanoparticles
    1. Turn on the lamps of the microscope and the laser 30 min before imaging. Put the petri dish containing the fixed cells (as explained in section 3.1) on the stage of the microscope.
    2. Collect the fluorescence from nanoparticles and DAPI by using filters as shown in Table 4. Overlay the phase contrast, nanoparticle and DAPI images in ImageJ software.
  2. Detection of ROS
    1. Turn on the lamps of the microscope 30 min before imaging. Put the petri dish containing the cells (as explained in section 3.2) on the stage of the microscope.
    2. Collect the fluorescence from nanoparticles, DAPI, and the ROS detecting reagent by using filters as shown in Table 4. Overlay the phase contrast, nanoparticle, DAPI and ROS detecting reagent images in ImageJ software.
  3. Apoptosis and necrosis by PI and annexin V FITC
    1. Turn on the lamps of the microscope 30 min before imaging. Put the Petri dish containing the cells (as explained in section 3.3) on the stage of the microscope.
    2. Collect the fluorescence from nanoparticles, DAPI, PI, and Annexin V FITC by using filters as shown in Table 4. Overlay the phase contrast, nanoparticle, DAPI, PI and Annexin V FITC images in ImageJ software.

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Results

Uptake and intrinsic cytotoxicity of nanoparticles

The 50 wt% blended MEH-PPV/PCBM nanoparticles were incubated with TE 71, MDA-MB-231, A549 and OVCAR3 cell lines. The PCBM blending level was chosen as 50 wt% PCBM, which has been shown to provide ideal charge and energy transfer properties between conjugated polymers and fullerenes14. Fluorescence images of nanoparticle uptake are shown in Figure 1B. Cells were incubated for 24 hr with nanoparticles to ensure nanopa...

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Discussion

To achieve nanoparticle uptake it was necessary to maintain some critical measures while fabricating the nanoparticles. A 10-6 M MEH-PPV solution (blended with 50 wt% PCBM) in THF was prepared to inject into DI water, as it was observed that the concentration of this solution plays an important role in determining the size of nanoparticles being formed. Concentration was checked by UV-vis spectroscopy. Note that in protocol step 2.1.3 it was necessary to dilute the initially prepared MEH-PPV solution (undilute...

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Disclosures

The authors have nothing to disclose.

Acknowledgements

The authors gratefully acknowledge the National Science Foundation (NSF) for financial support of this work through a CAREER award (CBET-0746210) and through award CBET-1159500. We would like to thank Dr. Turkson (Univ. of Hawaii Cancer Center) and Dr. Altomare (Univ. of Central Florida College of Medicine) for assistance with cell culture.

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Materials

List of materials used in this article
NameCompanyCatalog NumberComments
Poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene] (MEH-PPV)Sigma Aidrich536512-1Gaverage Mn 150,000-250,000
[6,6]-Phenyl C61 butyric acid methyl ester (PCBM)Sigma Aidrich684449-500MG>99.5%
Tetrahydrofuran (THF)EMDTX0284-6Drisolv
1 ml syringeNational Scientific Company37510-1For filtration of MEH-PPV solution
Syringe filterVWR28145-49525 mm, 0.2 µm, PTFE
1 ml syringeHamilton Company81320For injection of MEH-PPV solution into water to make nanoparticles
Dulbecco's Modification of Eagle's Medium/Ham's F-12 50/50 Mix (DMEM)Corning (VWR)45000-350
Hank's Balanced Salt Solution without phenol red (HBSS)Quality Biological (VWR)10128-740
Dulbecco's Phosphate-Buffered Saline, 1x without calcium and magnesium (DPBS)Corning (VWR)45000-436
Fetal Bovine Serum, Regular (Heat Inactivated) (FBS)Corning (VWR)45000-736
Trypsin EDTA 1x 0.25%Corning (VWR)45000-664Trypsin/2.21 mM EDTA in HBSS without sodium bicarbonate, calcium and magnesium Porcine Parvovirus Tested
16% ParaformaldehydeElectron Microscopy Sciences 1571016% paraformaldehyde is diluted to 4% by adding PBS
DAPI Biotium VWR89139-054Nuclear stain
5 ml pipettesVWR82050-478
75 cm2 culture flaskVWR82050-856for culturing cells
96-well platesVWR82050-771for MTT assays
Tissue Culture Dishes with VentsGreiner Bio-One (VWR)82050-538
Propidium iodideMolecular probesP3566
Annexin V FITCInvitrogenA13199dye for apoptosis
Celltiter 96 non-R 1000 assaysPromega (VWR)PAG4000MTT
CellROX Green Reagent, for oxidative stress detectionInvitrogenC10444For ROS detection
UV-vis spectrometerAgilent 8453
Fluorescence spectrometerNanoLog HoribaJobin Yvon
Dynamic light scatteringPD2000DLS, Precision detector
IncubatorNuAir DH Autoflow
Confocal microscopeZeiss Axioskop263X oil immersion objective lens
Epiluminescence microscopeOlympus IX7160X water immersion objective lens, Andor Zyla sCMOS camera
Solar SimulatorNewport 67005 Oriel Instruments
Reference solar cellOriel VLSI Standards Incorporated
Microplate readerBioTek Ex808
HemocytometerHausser Scientific Partnership3200For counting cells

References

  1. Dolmans, D., Fukumura, D., Jain, R. K. Photodynamic therapy for cancer. Nat Rev Cancer. 3 (5), 380-387 (2003).
  2. Dougherty, T. J., et al. Photodynamic therapy. J Natl Cancer Inst. 90 (12), 889-905 (1998).
  3. Ferrari, M. Cancer nanotechnology: Opportunities and challenges. Nat Rev Cancer. 5 (3), 161-171 (2005).
  4. Oleinick, N. L., Morris, R. L., Belichenko, T. The role of apoptosis in response to photodynamic therapy: what, where, why, and how. Photochem Photobiol Sci. 1 (1), 1-21 (2002).
  5. Ormond, A., Freeman, H. Dye Sensitizers for Photodynamic Therapy. Materials. 6 (3), 817-840 (2013).
  6. Pass, H. I. Photodynamic Therapy in Oncology - Mechanisms and Clinical Use. J Natl Cancer Inst. 85 (6), 443-456 (1993).
  7. Sariciftci, N. S., Smilowitz, L., Heeger, A. J., Wudl, F. Photoinduced electron transfer from a conducting polymer to buckminsterfullerene. Science. 258 (5087), 1474-1476 (1992).
  8. Sperandio, F. F., et al. Photoinduced electron-transfer mechanisms for radical-enhanced photodynamic therapy mediated by water-soluble decacationic C-70 and C84O2 Fullerene Derivatives. Nanomed-Nanotechnol. 9 (4), 570-579 (2013).
  9. Fan, J. Q., Fang, G., Zeng, F., Wang, X. D., Wu, S. Z. Water-Dispersible Fullerene Aggregates as a Targeted Anticancer Prodrug with both Chemo- and Photodynamic Therapeutic Actions. Small. 9 (4), 613-621 (2013).
  10. Grynyuk, I., et al. Photoexcited fullerene C-60 disturbs prooxidant-antioxidant balance in leukemic L1210 cells. Materialwiss Werkstofftech. 44 (2-3), 139-143 (2013).
  11. Liu, X. M., et al. Separately doped upconversion-C-60 nanoplatform for NIR imaging-guided photodynamic therapy of cancer cells. Chem Commun. 49 (31), 3224-3226 (2013).
  12. Trpkovic, A., Todorovic-Markovic, B., Trajkovic, V. Toxicity of pristine versus functionalized fullerenes: mechanisms of cell damage and the role of oxidative stress. Arch Toxicol. 86 (12), 1809-1827 (2012).
  13. Chen, Z. Y., MA, L. J., Liu, Y., Chen, C. Y. Applications of Functionalized Fullerenes in Tumor Theranostics. Theranostics. 2 (3), 238-250 (2012).
  14. Park, S. H., et al. Bulk heterojunction solar cells with internal quantum efficiency approaching 100%. Nat Photonics. 3 (5), 297-302 (2009).

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Conducting Polymer NanoparticlesFullerene PCBMNanoparticle FabricationPrecipitation MethodCell Uptake AnalysisROS DetectionMTT AssayFluorescence ImagingSolar Simulator
Photodynamic Therapy with Blended Conducting Polymer/Fullerene Nanoparticle Photosensitizers
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