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.

1. Culturing Cell Lines
<ol>
	<li>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.</li>
	<li>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...

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

The authors have nothing to disclose.

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...

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.

<table border="0" cellpadding="0" cellspacing="0">
	<tbody>
		<tr>
			<td>Poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene] (MEH-PPV)</td>
			<td>Sigma Aidrich</td>
			<td>536512-1G</td>
			<td>average Mn&#160;150,000-250,000</td>
		</tr>
		<tr>
			<td>[6,6]-Phenyl C61&#160;butyric acid methyl ester (PCBM)</td>
			<td>Sigma Aidrich</td>
			<td>684449-500MG</td>
			<td>&#62; 99.5%</td>
		</tr>
		<tr>
			<td>Tetrahydrofuran (THF)</td>
			<td>EMD</td>
			<td>TX0284-6</td>
			<td>Drisolv</td>
		</tr>
		<tr>
			<td>1 ml syringe</td>
			<td>National Scientific Company</td>
			<td>37510-1</td>
			<td>For filtration of MEH-PPV solution</td>
		</tr>
		<tr>
			<td>Syringe filter</td>
			<td>VWR</td>
			<td>28145-495</td>
			<td>25 mm, 0.2 &#181;m, PTFE</td>
		</tr>
		<tr>
			<td>1 ml syringe</td>
			<td>Hamilton Company</td>
			<td>81320</td>
			<td>For injection of MEH-PPV solution into water to make nanoparticles</td>
		</tr>
		<tr>
			<td>Dulbecco&#39;s Modification of Eagle&#39;s Medium/Ham&#39;s F-12 50/50 Mix (DMEM)</td>
			<td>Corning (VWR)</td>
			<td>45000-350</td>
			<td></td>
		</tr>
		<tr>
			<td>Hank&#39;s Balanced Salt Solution without phenol red (HBSS)</td>
			<td>Quality Biological (VWR)</td>
			<td>10128-740</td>
			<td></td>
		</tr>
		<tr>
			<td>Dulbecco&#39;s Phosphate-Buffered Saline, 1X without calcium and magnesium (DPBS)</td>
			<td>Corning (VWR)</td>
			<td>45000-436</td>
			<td></td>
		</tr>
		<tr>
			<td>Fetal Bovine Serum, Regular (Heat Inactivated) (FBS)</td>
			<td>Corning (VWR)</td>
			<td>45000-736</td>
			<td></td>
		</tr>
		<tr>
			<td>Trypsin EDTA 1X 0.25%</td>
			<td>Corning (VWR)</td>
			<td>45000-664</td>
			<td>Trypsin/2.21 mM EDTA in HBSS without sodium bicarbonate, calcium and magnesium Porcine Parvovirus Tested</td>
		</tr>
		<tr>
			<td>16% Paraformaldehyde</td>
			<td>Electron Microscopy Sciences&#160;</td>
			<td>15710</td>
			<td>16% paraformaldehyde is diluted to 4% by adding PBS</td>
		</tr>
		<tr>
			<td>DAPI</td>
			<td>&#160;Biotium VWR</td>
			<td>89139-054</td>
			<td>Nuclear stain</td>
		</tr>
		<tr>
			<td>5 ml pipettes</td>
			<td>VWR</td>
			<td>82050-478</td>
			<td></td>
		</tr>
		<tr>
			<td>75 cm2 culture flask</td>
			<td>VWR</td>
			<td>82050-856</td>
			<td>for culturing cells</td>
		</tr>
		<tr>
			<td>96-well plates</td>
			<td>VWR</td>
			<td>82050-771</td>
			<td>for MTT assays</td>
		</tr>
		<tr>
			<td>Tissue Culture Dishes with Vents</td>
			<td>Greiner Bio-One (VWR)</td>
			<td>82050-538</td>
			<td></td>
		</tr>
		<tr>
			<td>Propidium iodide</td>
			<td>Molecular probes</td>
			<td>P3566</td>
			<td></td>
		</tr>
		<tr>
			<td>Annexin V FITC</td>
			<td>Invitrogen</td>
			<td>A13199</td>
			<td>dye for apoptosis</td>
		</tr>
		<tr>
			<td>Celltiter 96 non-R 1000 assays</td>
			<td>Promega (VWR)</td>
			<td><a href="https://www.vwrsp.com/catalog/product/index.cgi?catalog_number=PAG4000">PAG4000</a></td>
			<td>MTT</td>
		</tr>
		<tr>
			<td>CellROX Green Reagent, for oxidative stress detection</td>
			<td>Invitrogen</td>
			<td>C10444</td>
			<td>For ROS detection</td>
		</tr>
		<tr>
			<td>UV-vis spectrometer</td>
			<td>Agilent 8453</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Fluorescence spectrometer</td>
			<td>NanoLog HoribaJobin Yvon</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Dynamic light scattering</td>
			<td>PD2000DLS, Precision detector</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Incubator</td>
			<td>NuAir DH Autoflow</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Confocal microscope</td>
			<td>Zeiss Axioskop2</td>
			<td></td>
			<td>63X oil immersion objective lens</td>
		</tr>
		<tr>
			<td>Epiluminescence microscope</td>
			<td>Olympus IX71</td>
			<td></td>
			<td>60X water immersion objective lens, Andor Zyla sCMOS camera</td>
		</tr>
		<tr>
			<td>Solar Simulator</td>
			<td>Newport 67005 Oriel Instruments</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Reference solar cell</td>
			<td>Oriel&#160;</td>
			<td></td>
			<td>VLSI Standards Incorporated</td>
		</tr>
		<tr>
			<td>Microplate reader</td>
			<td>BioTek Ex808</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Hemocytometer</td>
			<td>Hausser Scientific Partnership</td>
			<td>3200</td>
			<td>For counting cells</td>
		</tr>
	</tbody>
</table>

photodynamic therapy with blended conducting polymer/fullerene nanoparticle photosensitizers

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.

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...

Watch this Scientific Journal Video about Photodynamic Therapy with Blended Conducting Polymer/Fullerene Nanoparticle Photosensitizers at JoVE.com

Photodynamic Therapy with Blended Conducting Polymer/Fullerene Nanoparticle Photosensitizers

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).

In this article a method for the fabrication and reproducible in-vitro evaluation of conducting polymer nanoparticles blended with fullerene as the next ...

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8.4K visualizações.  University of Central Florida. 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). 