Los autores desean agradecer a biolitec Research GmbH (Jena, Alemania) por la amabilidad de darnos la formulación liposomal mTHPC, con un agradecimiento especial a Susanna Gräfe y Arno Wiehe por su ayuda y conocimientos técnicos. También nos gustaría dar las gracias a Kerstin Reidy, que genera una gran parte de los resultados y fue corresponsable de su publicación 11. Este trabajo fue apoyado por becas de la Schweizerischer Verein Balgrist, la Universidad de Zurich, el Krebsliga Zurich, así como por una beca de la Walter L. y Johanna Fundación Wolf, Zurich, Suiza, y una beca de EuroNanoMed ERA-NET / SNF suizo Fundación Nacional para la Ciencia 31NM30-131004/1. Este trabajo también fue apoyado por el programa (de Alta Especialidad de Medicina) para musculoesqueléticos Oncología del Cantón de Zurich HSM.

1. La comparación de la captación de mTHPC en los respectivos baja y altamente metastásico HOS y Líneas Celulares 143B OS <ol><li> Preparar el medio de cultivo celular que contenía DMEM, Jamón F12, y suero fetal inactivado por calor ternera en un 4.5:4.5:1 relación. Nota: La formulación liposomal de la PS mTHPC se disolvió en agua a una concentración final de 1,5 mg / ml mTHPC. </li><li> Plate 0,2 x 10 6 células HOS y 143B / pocillo en placas de 6 pocillos (triplica para cada condición) y dejar que las células se adhieran durante la noche. Nota: el número tiene que ser ajustado a las líneas de células individuales. Una confluencia de 80-90% es el más adecuado en el momento del experimento. </li><li> Al día siguiente, incubar las células con una concentración fija de mTHPC para diferentes períodos de tiempo (de absorción dependiente del tiempo), o con concentraciones crecientes de mTHPC durante un período de tiempo fijo (dosis dependiente de la captación). </li><li> Se incuban las células con mTHPC de tiempo específico para points o concentraciones de mTHPC. Nota: En este estudio, tanto el HOS y líneas de células 143B se incubaron con 0,6 g / ml mTHPC de 0, 2,5, 5, o 10 horas, o con 0, 0,6, 2,5, y 10 g / ml mTHPC durante 5 h. Los períodos de tiempo y las dosis aplicadas pueden variar dependiendo de la línea celular que se utiliza. </li><li> Recuerde que debe trabajar siempre en la oscuridad o en condiciones de luz tenue para evitar exposición a la luz directa de las células. </li><li> Después de la incubación de las células en las condiciones indicadas, aspirar el medio y lavar las células tres veces con PBS. A continuación, separar las células con 0,5 ml de tripsina / EDTA y contar las células. </li><li> Después de la separación, centrifugar las células a 400 xg durante 5 min, aspirar el medio y volver a suspender las células en PBS a una densidad final de 200.000 células / ml. </li><li> Pipetear 100 l de la suspensión celular obtenida (es decir, 20.000 células) en una placa de 96 pocillos y medir la fluorescencia de estas células en un espectrofotómetro de fluorescencia. El ajustes para mediciones de fluorescencia mTHPC son: 417 nm para la excitación y 652 nm para la emisión. </li><li> Con el fin de calcular la cantidad de mTHPC internalizada por célula, normalizar la unidad de fluorescencia relativa (RFU) para el número de células y el volumen celular de la siguiente manera: </li><li> Preparar una curva estándar utilizando diferentes concentraciones de mTHPC en PBS de 0-4 g / ml (medidas uso por triplicado). Pipetear 100 l de cada dilución en una placa de 96 pocillos y medir la fluorescencia de los pozos utilizando los ajustes que se describen en el paso 1.6. </li><li> Divida la RFU (obtenido de 20.000 células) por la pendiente de la curva estándar lineal de mTHPC, que muestra la concentración de mTHPC (en g / ml) en el pozo. </li><li> Divida esta concentración mTHPC por 10 para obtener la cantidad total de mTHPC en un pocillo (en microgramos, lo que representa 100 l de suspensión celular) y dividir este valor por el volumen de 20.000 células. </li><li> Calcular el volumen con la fórmula para una esfera: (4/3 x π) xr 3. Obtener el radio r midiendo el diámetro de 20 células tratadas con tripsina bajo un microscopio, y dividiendo este valor por 2. </li><li> Finalmente, normalizar todos los valores a los obtenidos para las células HOS después de 10 horas de incubación (dosis absorción dependiente) o tratados con 10 mg / ml mTHPC (absorción dependiente del tiempo), que se establece en 100%. </li></ol> 2. Medición de la fototoxicidad in vitro de PS <ol><li> Seed 3000 células / pocillo en una placa de 96 pocillos (por triplicado para cada concentración de mTHPC utilizados) y dejar que ellos se adhieran noche a la mañana. Del mismo modo preparar una placa de 96 pozos adicionales y tratar las células como se describe a continuación, pero a continuación, poner a un lado para obtener imágenes de contraste de fase. Nota: el número tiene que ser ajustado para cada línea celular individual. Una confluencia del 50-60% en el momento del experimento es ideal. <ol><li> Tenga en cuenta que añadir el correspondiente control de toxicidad en la oscuridad de las células de cada una de las concentraciones mTHPC. LaSE son células que se incubaron en ausencia o presencia de concentraciones seleccionadas de mTHPC, pero no se ilumina. </li></ol></li><li> Al día siguiente, incubar las células con diferentes concentraciones de mTHPC (0, 0,0001, 0,001, 0,01, 0,03, 0,075, 0,15, 0,3, 0,6, 1,25, 2,5, 5, y 10 g / ml) en función de las líneas celulares y mantenerlos en la oscuridad durante 5 horas. <ol><li> Consulte la Sección 1.3.2 Nota: El tiempo de incubación antes de la iluminación depende de la línea celular y en la PS se utiliza, por lo tanto, es aconsejable para probar diferentes concentraciones y diferentes puntos de tiempo en experimentos separados. </li></ol></li><li> Después de la incubación para el período de tiempo indicado, se lavan las células dos veces con PBS y añadir medio fresco sin mTHPC. </li><li> Iluminar las células con un láser de diodo de 652 nm, específico para el espectro de absorción mTHPC (véase la Figura 1). <ol><li> Ajuste el láser para 21.88 mW / cm Potencia de 2 a una altura de 13,5 cm distaNCE de las células, con el fin de obtener una dosis de energía de 5 J / cm 2. Ilumine las células durante 230 seg. No iluminar las células de control de toxicidad oscuros (con y sin mTHPC). Nota: Siempre use gafas para proteger los ojos de la luz láser que se utiliza para la excitación del PS. </li></ol></li><li> Después de la iluminación, mantener las células en la oscuridad a 37 º C durante 24 horas. Posteriormente, se añade agua tetrazolio soluble (WST-1) reactivo (10 μl/100 l de medio). </li><li> Tres horas después de la adición del reactivo WST-1, medir la absorbancia de los pocillos individuales de la placa de 96 pocillos a 415 nm. </li><li> Con el fin de calcular el porcentaje de células supervivientes, establecer la media de los valores obtenidos para las células no tratadas mTHPC para cada condición a 100% (es decir, sistema de iluminación, sin mTHPC y nonilluminated, sin mTHPC). </li></ol> 3. Estimación del número de células por Recuento celular <ol><li> Se siembran las células 20000 / nosotrosll en una placa de 24 pocillos y dejar que ellos se adhieran noche a la mañana. </li><li> Se incuban las células durante 5 h con mTHPC (0,001, 0,003, 0,15, 0,6, y 1,25 g / ml) e iluminar ellos como se describe anteriormente. </li><li> Recoger el medio, se lavan las células una vez con PBS, trypsinize ellos y recogerlas por centrifugación a 400 xg durante 5 min. </li><li> Después de la centrifugación, aspirar el medio y volver a suspender las células en 200 l de medio fresco. </li><li> Contar las células en una cámara de Neubauer. </li></ol>

<ol>
	<li>Juarranz, A., Jaen, P., Sanz-Rodriguez, F., Cuevas, J., Gonzalez, S. <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+of+cancer.+Basic+principles+and+applications.">Photodynamic therapy of cancer. Basic principles and applications.</a> Clin. Transl. Oncol. 10, 148-154 (2008).</li><li>Agostinis, P., 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+of+cancer:+an+update.">Photodynamic therapy of cancer: an update.</a> CA Cancer. 61, 250-281 (2011).</li><li>D'Adamo, D. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Appraising+the+current+role+of+chemotherapy+for+the+treatment+of+sarcoma.">Appraising the current role of chemotherapy for the treatment of sarcoma.</a> Semin. Oncol. 38 Suppl 3, 19-29 (2011).</li><li>Allison, D. C., 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=A+meta-analysis+of+osteosarcoma+outcomes+in+the+modern+medical+era.">A meta-analysis of osteosarcoma outcomes in the modern medical era.</a> Sarcoma. , (2012).</li><li>Anninga, J. K., 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=Chemotherapeutic+adjuvant+treatment+for+osteosarcoma:+where+do+we+stand.">Chemotherapeutic adjuvant treatment for osteosarcoma: where do we stand.</a> Eur. J. Cancer. 47, 2431-2445 (2011).</li><li>Bacci, G., 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=Pattern+of+relapse+in+patients+with+osteosarcoma+of+the+extremities+treated+with+neoadjuvant+chemotherapy.">Pattern of relapse in patients with osteosarcoma of the extremities treated with neoadjuvant chemotherapy.</a> Eur. J. Cancer. 37, 32-38 (2001).</li><li>Briccoli, A., 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=Resection+of+recurrent+pulmonary+metastases+in+patients+with+osteosarcoma.">Resection of recurrent pulmonary metastases in patients with osteosarcoma.</a> Cancer. 104, 1721-1725 (2005).</li><li>Milla Sanabria, L., 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=Direct+and+indirect+photodynamic+therapy+effects+on+the+cellular+and+molecular+components+of+the+tumor+microenvironment.">Direct and indirect photodynamic therapy effects on the cellular and molecular components of the tumor microenvironment.</a> Biochim. Biophys. Acta. 1835, 36-45 (2013).</li><li>Mitra, S., Foster, T. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Photophysical+parameters,+photosensitizer+retention+and+tissue+optical+properties+completely+account+for+the+higher+photodynamic+efficacy+of+meso-tetra-hydroxyphenyl-chlorin+vs+Photofrin.">Photophysical parameters, photosensitizer retention and tissue optical properties completely account for the higher photodynamic efficacy of meso-tetra-hydroxyphenyl-chlorin vs Photofrin.</a> Photochem. Photobiol. 81, 849-859 (2005).</li><li>Ma, L., Moan, J., Berg, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Evaluation+of+a+new+photosensitizer,+meso-tetra-hydroxyphenyl-chlorin,+for+use+in+photodynamic+therapy:+a+comparison+of+its+photobiological+properties+with+those+of+two+other+photosensitizers.">Evaluation of a new photosensitizer, meso-tetra-hydroxyphenyl-chlorin, for use in photodynamic therapy: a comparison of its photobiological properties with those of two other photosensitizers.</a> Int. J. Cancer. 57, 883-888 (1994).</li><li>Reidy, K., Campanile, C., Muff, R., Born, W., Fuchs, B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=mTHPC-mediated+photodynamic+therapy+is+effective+in+the+metastatic+human+143B+osteosarcoma+cells.">mTHPC-mediated photodynamic therapy is effective in the metastatic human 143B osteosarcoma cells.</a> Photochem. Photobiol. 88, 721-727 (2012).</li><li>Triesscheijn, M., Ruevekamp, M., Aalders, M., Baas, P., Stewart, F. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Comparative+sensitivity+of+microvascular+endothelial+cells,+fibroblasts+and+tumor+cells+after+in+vitro+photodynamic+therapy+with+meso-tetra-hydroxyphenyl-chlorin.">Comparative sensitivity of microvascular endothelial cells, fibroblasts and tumor cells after in vitro photodynamic therapy with meso-tetra-hydroxyphenyl-chlorin.</a> Photochem. Photobiol. 80, 236-241 (2004).</li><li>Triesscheijn, M., Baas, P., Schellens, J. H., Stewart, F. A. <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.">Photodynamic therapy in oncology.</a> Oncologist. 11, 1034-1044 (2006).</li><li>Burch, S., 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=Treatment+of+canine+osseous+tumors+with+photodynamic+therapy:+a+pilot+study.">Treatment of canine osseous tumors with photodynamic therapy: a pilot study.</a> Clin. Orthop. Relat. Res. 467, 1028-1034 (2009).</li></ol>

Los autores declaran no tener intereses financieros en competencia o conflictos de intereses.

Para lograr citotoxicidad óptimo en respuesta a PDT, es fundamental para elegir los ajustes de luz láser adecuados y los tiempos de incubación. Los procedimientos aquí descritos son consistentes y eficientes para determinar la absorción de PS y cuantificar la citotoxicidad inducida por la TFD in vitro. El uso de las longitudes de onda de absorción específica de la PS mTHPC, la absorción de PS celular se puede determinar de una manera directa, y la PS se puede activar para generar especies de oxígeno re...

Estado actual del tratamiento del arte del osteosarcoma (OS), un tumor óseo primario, abarca una combinación de quimioterapia adyuvante neo y la cirugía. Este régimen de tratamiento reveló un aumento en la tasa de supervivencia de los pacientes con enfermedad localizada de aproximadamente 20% antes del uso de la quimioterapia, a actualmente entre 60-70% 3, 4. Sin embargo, en las últimas dos décadas, la supervivencia global de los pacientes OS con enfermedad local se ha estancado 4, 5. Por otra parte, el 30-40% de los pacientes recae dentro de 3 años después del diagnóstico y los pacientes con enfermedad metastásica siguen teniendo una baja supervivencia de 20-30% 4, 6, 7. Para mejorar el resultado de estos pacientes, las nuevas estrategias terapéuticas deben ser desarrollados. Terapia fotodinámica (PDT), en lugar de una nueva terapia contra el cáncer, utiliza la luz de una longitud de onda específica para la excitación de un fotosensibleTizer (PS), que se acumula en las células tumorales después de su inyección en el torrente sanguíneo. La luz del láser de excitación de la PS genera radicales de oxígeno en la presencia de oxígeno, que inducen reacción citotóxica en las células tumorales y la muerte celular. Además de este mecanismo primaria, dos adicionales PDT evocados procesos biológicos contribuyen al crecimiento del tumor reducida: PDT causa vasoconstricción y la formación de trombos de la microvasculatura del tumor y, por consiguiente, la hipoxia local y la anoxia el interior del tumor, lo que lleva a un infarto del tumor. Por último, PDT lesiona y mueren las células tumorales activan una respuesta inmune local, una característica muy especial de la TFD. Esto implica el sistema del complemento y la activación de células presentadoras de antígeno dendríticas 8. Por lo tanto, se crean condiciones para la presentación de antígenos tumorales con la posterior activación de las células linfoides, que conduce a la inmunidad específica de tumor. Hasta ahora, la TFD se ha usado para tratar varios tipos de tumores de tejidos blandos y hyperplasia de, como queratosis actínica, el esófago de Barrett, los tumores endobronquiales, cáncer de vejiga, carcinomas de células basales y el tratamiento paliativo del cáncer de cabeza y cuello 2. El tratamiento se sabe que inducen, la necrosis local a gran escala con sólo pocos efectos secundarios, y por lo tanto tiene el potencial para erradicar selectivamente el tejido tumoral. A pesar de estas ventajas, la aplicación de la TFD sigue siendo técnicamente más exigente que la administración de fármacos quimioterapéuticos. Con el fin de lograr la máxima eficacia, la concentración de PS, el tiempo de exposición a la luz y la transferencia total de energía de la luz necesita ser optimizado. Esto se puede hacer en experimentos in vivo, pero, debido a la gran número relativo de parámetros que necesitan ser optimizados, es más eficiente para determinar inicialmente las condiciones óptimas in vitro. En los experimentos que se describen a continuación, hemos probado la eficacia in vitro de la TFD con una EP 5,10,15,20-tetrakis (meta-hidroxifenil) chlorin, abreviado mTHPC (Figura 1A). mTHPC es la sustancia activa en el producto medicinal Foscan, que se utiliza actualmente en la clínica para el tratamiento paliativo del cáncer de cabeza y cuello. Es uno de los PS más potente, la inducción de daño celular masiva ya a bajas concentraciones, y se demostró que es superior a otra PS en términos de penetración en el tejido 9, 10. Su espectro de absorción de la luz (Figura 1B) muestra dos picos prominentes, uno a 417 nm y un segundo a 652 nm, que se utilizan para la localización de tejido de acumulación de PS y para PDT de inducción, respectivamente. En la actualidad, una formulación liposomal de mTHPC está en desarrollo. A continuación, describimos los procedimientos para cuantificar la absorción de esta formulación liposomal, y para llevar a cabo la TFD en dos líneas celulares humanas OS, el bajo HOS metastásico y las células metastásicas 143B altos. Algunos de los datos que aquí se presentan han sido reportados anteriormente 11. Thenfoque E descrito aquí nos permite estudiar el efecto de un fenotipo metastásico en la eficacia de la TFD. 143B células ortotópicamente, inyectados en las extremidades traseras de los ratones SCID inmunodeficientes causan intratibial tumores primarios en metástasis, un modelo que imita estrechamente la enfermedad metástasis humana. Por lo tanto, los experimentos in vitro propuestas son perfectamente adecuados para evaluar los ajustes óptimos PDT que se utilizarán posteriormente en experimentos in vivo.

<table border="0" cellpadding="0" cellspacing="0" width="955">
	<colgroup>
		<col />
		<col />
		<col />
		<col />
	</colgroup>
	<tbody>
		<tr height="21">
			<td height="21" style="height:21px;width:291px;">DMEM</td>
			<td style="width:251px;">PAA GmbH, Freiburg, Germany</td>
			<td style="width:127px;">E15-883</td>
			<td style="width:287px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:291px;">HAM F12</td>
			<td>PAA GmbH, Freiburg, Germany</td>
			<td style="width:127px;">E15-817</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:291px;">heat-inactivated fetal calf serum</td>
			<td>GIBCO, Basel, Switzerland</td>
			<td style="width:127px;">10500-064</td>
			<td></td>
		</tr>
		<tr height="147">
			<td height="147" style="height:147px;width:291px;">mTHPC</td>
			<td style="width:251px;">biolitec research GmbH, Jena, Germany</td>
			<td style="width:127px;"></td>
			<td style="width:287px;">As this liposomal formulation is originating from R &#38; D 
			no catalogue number is available at the moment. Stock: 1.5mg/ml; provided in a 9:1 mixture of dipalmitoylphosphatidylcholine (DPPC) and dipalmitoylphosphatidylglycerol (DPPG; &#62;99% purity)</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Spectramax Gemini XS plate reader</td>
			<td style="width:251px;">Molecular Devices, Sunnyvale, CA</td>
			<td style="width:127px;">ID# 861</td>
			<td></td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:291px;">Microscope Zeiss Observer.Z1</td>
			<td style="width:251px;">Axio Observer, Axio Vision Release 4.6.3 SP1, Jena Germany</td>
			<td style="width:127px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:291px;">Ceralas PDT 652 nm Laser</td>
			<td style="width:251px;">Biolitec AG, Jena, Germany</td>
			<td style="width:127px;">LD652nm2W400u</td>
			<td></td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:291px;">Water-soluble tetrazolium (WST) reagent</td>
			<td style="width:251px;">Roche Diagnostics AG, Rotkreuz, Switzerland</td>
			<td style="width:127px;">1644807</td>
			<td></td>
		</tr>
	</tbody>
</table>

cytotoxic efficacy of photodynamic therapy in osteosarcoma cells in vitro

En los últimos años, ha sido la dificultad en la búsqueda de terapias más eficaces contra el cáncer con menos efectos secundarios sistémicos. Por lo tanto la terapia fotodinámica es un nuevo enfoque para el tratamiento selectivo del tumor más. Terapia fotodinámica (PDT) que hace uso de un fotosensibilizador no tóxico (PS), que, tras la activación con luz de una longitud de onda específica en la presencia de oxígeno, genera radicales de oxígeno que provocan una respuesta citotóxica 1. A pesar de su aprobación hace casi veinte años por la FDA, PDT es hoy en día sólo se utiliza para tratar un número limitado de tipos de cáncer (de piel, de la vejiga) y las enfermedades no oncológico (psoriasis, queratosis actínica) 2. La principal ventaja de la utilización de la PDT es la capacidad de realizar un tratamiento local, lo que evita efectos secundarios sistémicos. Además, permite el tratamiento de tumores en sitios delicados (por ejemplo, alrededor de los nervios o vasos sanguíneos). Aquí, un intraoperative aplicación de la TFD se considera en el osteosarcoma (OS), un tumor de la médula, para apuntar los satélites de tumor primario queda atrás en el tumor de tejido circundante después de la resección quirúrgica del tumor. El tratamiento tiene como objetivo disminuir el número de recurrencias y a reducir el riesgo de (postoperatoria) la metástasis. En el presente estudio, se presentan en los procedimientos in vitro PDT para establecer la configuración de PDT óptimas para el tratamiento eficaz de las líneas celulares usadas ampliamente OS que se utilizan para reproducir la enfermedad humana en modelos de ratón OS intratibial bien establecidos. La absorción de la PS mTHPC se examinó con un espectrofotómetro y fototoxicidad se provocaron con la luz láser de excitación de mTHPC a 652 nm para inducir la muerte celular evaluada con un ensayo de WST-1 y por el recuento de células supervivientes. Las técnicas establecidas nos permiten definir los ajustes óptimos PDT para futuros estudios en modelos animales. Son una herramienta fácil y rápida para la evaluación de la eficacia de la terapia fotodinámica <em&gt; In vitro antes de una aplicación in vivo.

Con las técnicas aquí reportados, se investigó PDT basada en mTHPC en OS células humanas. En primer lugar, el tiempo y la dosis de absorción depende de mTHPC se investigó en la baja HOS metastásico y en las líneas de células 143B OS altamente metastásicas. mTHPC absorción se puede evaluar mediante la medición de la fluorescencia de mTHPC con un espectrofotómetro de fluorescencia (Figura 2, reproducido con permiso de Reidy et al. 11). Figura 2A ilustra la...

Watch this Scientific Journal Video about Cytotoxic Efficacy of Photodynamic Therapy in Osteosarcoma Cells In Vitro at JoVE.com

Cytotoxic Efficacy of Photodynamic Therapy in Osteosarcoma Cells In Vitro

El protocolo informado aquí permite la evaluación de la eficacia de la terapia fotodinámica (PDT) en líneas de células y la optimización de la configuración de PDT antes de aplicar la terapia en modelos animales.

Citotóxica eficacia de la terapia fotodinámica en células de osteosarcoma<em&gt; In Vitro</em

In recent years, there has been the difficulty in finding more effective therapies against cancer with less systemic side effects. Therefore Photodynamic ...

cytotoxic-efficacy-photodynamic-therapy-osteosarcoma-cells

Research

JoVE Journal

Medicine

Cytotoxic Efficacy of Photodynamic Therapy in Osteosarcoma Cells In Vitro

12.7K vistas.  Balgrist University Hospital, Zurich, Switzerland.  El protocolo informado aquí permite la evaluación de la eficacia de la terapia fotodinámica (PDT) en líneas de células y la optimización de la configuración de PDT antes de aplicar la terapia en modelos animales. 

Video: Cytotoxic Efficacy of Photodynamic Therapy in Osteosarcoma Cells In Vitro

Subretinal Injection of Gene Therapy Vectors and Stem Cells in the Perinatal Mouse Eye

The loss of sight affects approximately 3.4 million people in the United States and is expected to increase in the upcoming years.1 Recently, gene therapy and stem cell transplantations have become key therapeutic tools for treating blindness resulting from retinal degenerative diseases. Several forms of autologous transplantation for age-related macular degeneration (AMD), such as iris pigment epithelial cell transplantation, have generated encouraging results, and human clinical trials have begun for other forms of gene and stem cell therapies.2 These include RPE65 gene replacement therapy in patients with Leber's congenital amaurosis and an RPE cell transplantation using human embryonic stem (ES) cells in Stargardt's disease.3-4 Now that there are gene therapy vectors and stem cells available for treating patients with retinal diseases, it is important to verify these potential therapies in animal models before applying them in human studies. The mouse has become an important scientific model for testing the therapeutic efficacy of gene therapy vectors and stem cell transplantation in the eye.5-8 In this video article, we present a technique to inject gene therapy vectors or stem cells into the subretinal space of the mouse eye while minimizing damage to the surrounding tissue.

This surgical technique illustrates the injection of gene therapy vectors and stem cells into the subretinal space of the mouse eye.

Inyección subretiniana de vectores de terapia génica y células madre en el ojo del ratón

The loss of sight affects approximately 3.4 million people in the United States and is expected to increase in the upcoming years.1 Recently, gene therapy ...

Investigación

Medicina

In vitro Enrichment of Ovarian Cancer Tumor-initiating Cells

Evidence suggests that small subpopulations of tumor cells maintain a unique self-renewing and differentiation capacity and may be responsible for tumor initiation and/or relapse. Clarifying the mechanisms by which these tumor-initiating cells (TICs) support tumor formation and progression could lead to the development of clinically favorable therapies. Ovarian cancer is a heterogeneous and highly recurrent disease. Recent studies suggest TICs may play an important role in disease biology. We have identified culture conditions that enrich for TICs from ovarian cancer cell lines. Growing either adherent cells or non-adherent &#8216;floater&#8217; cells in a low attachment plate with serum free media in the presence of growth factors supports the propagation of ovarian cancer TICs with stem cell markers (CD133 and ALDH activity) and increased tumorigenicity without the need to physically separate the TICs from other cell types within the culture. Although the presence of floater cells is not common for all cell lines, this population of cells with innate low adherence may have high tumorigenic potential.Compared to adherent cells grown in the presence of serum, TICs readily form spheres, are significantly more tumorigenic in mice, and express putative stem cell markers. The conditions are easy to establish in a timely manner and can be used to study signaling pathways important for maintaining stem characteristics, and to identify drugs or combinations of drugs targeting TICs. The culture conditions described herein are applicable for a variety of ovarian cancer cells of epithelial origin and will be critical in providing new information about the role of TICs in tumor initiation, progression, and relapse.

In vitro Enrichment of Ovarian Cancer Tumor-initiating Cells

Tumor-initiating cells (TICs) may represent a viable therapeutic target for the treatment of ovarian cancer, a highly recurrent and fatal disease. We present a protocol for culture conditions that enrich for this highly tumorigenic population of cells.

En Enriquecimiento vitro de células iniciadoras del tumor del cáncer de ovario

Evidence suggests that small subpopulations of tumor cells maintain a unique self-renewing and differentiation capacity and may be responsible for tumor ...

Studying Pancreatic Cancer Stem Cell Characteristics for Developing New Treatment Strategies

Pancreatic ductal adenocarcinoma (PDAC) contains a subset of exclusively tumorigenic cancer stem cells (CSCs) which have been shown to drive tumor initiation, metastasis and resistance to radio- and chemotherapy. Here we describe a specific methodology for culturing primary human pancreatic CSCs as tumor spheres in anchorage-independent conditions. Cells are grown in serum-free, non-adherent conditions in order to enrich for CSCs while their more differentiated progenies do not survive and proliferate during the initial phase following seeding of single cells. This assay can be used to estimate the percentage of CSCs present in a population of tumor cells. Both size (which can range from 35 to 250 micrometers) and number of tumor spheres formed represents CSC activity harbored in either bulk populations of cultured cancer cells or freshly harvested and digested tumors 1,2. Using this assay, we recently found that metformin selectively ablates pancreatic CSCs; a finding that was subsequently further corroborated by demonstrating diminished expression of pluripotency-associated genes/surface markers and reduced in vivo tumorigenicity of metformin-treated cells. As the final step for preclinical development we treated mice bearing established tumors with metformin and found significantly prolonged survival. Clinical studies testing the use of metformin in patients with PDAC are currently underway (e.g., NCT01210911, NCT01167738, and NCT01488552). Mechanistically, we found that metformin induces a fatal energy crisis in CSCs by enhancing reactive oxygen species (ROS) production and reducing mitochondrial transmembrane potential. In contrast, non-CSCs were not eliminated by metformin treatment, but rather underwent reversible cell cycle arrest. Therefore, our study serves as a successful example for the potential of in vitro sphere formation as a screening tool to identify compounds that potentially target CSCs, but this technique will require further in vitro and in vivo validation to eliminate false discoveries.

Pancreatic cancer stem cells (CSCs) can be expanded in vitro using the anchorage-independent sphere culture technique, which represents a powerful tool to study CSC biology and can serve as the first step to develop novel CSC-targeting therapies. Here the methodology for expanding, analyzing and targeting of pancreatic CSCs is provided.

El estudio de cáncer de páncreas Tallo Características de las células para el desarrollo de nuevas estrategias de tratamiento

Pancreatic ductal adenocarcinoma (PDAC) contains a subset of exclusively tumorigenic cancer stem cells (CSCs) which have been shown to drive tumor ...

Depletion of Mouse Cells from Human Tumor Xenografts Significantly Improves Downstream Analysis of Target Cells

The use of in vitro cell line models for cancer research has been a useful tool. However, it has been shown that these models fail to reliably mimic patient tumors in different assays1. Human tumor xenografts represent the gold standard with respect to tumor biology, drug discovery, and metastasis research 2-4. Tumor xenografts can be derived from different types of material like tumor cell lines, tumor tissue from primary patient tumors4 or serially transplanted tumors. When propagated in vivo, xenografted tissue is infiltrated and vascularized by cells of mouse origin. Multiple factors such as the tumor entity, the origin of xenografted material, growth rate and region of transplantation influence the composition and the amount of mouse cells present in tumor xenografts. However, even when these factors are kept constant, the degree of mouse cell contamination is highly variable.
Contaminating mouse cells significantly impair downstream analyses of human tumor xenografts. As mouse fibroblasts show high plating efficacies and proliferation rates, they tend to overgrow cultures of human tumor cells, especially slowly proliferating subpopulations. Mouse cell derived DNA, mRNA, and protein components can bias downstream gene expression analysis, next-generation sequencing, as well as proteome analysis 5. To overcome these limitations, we have developed a fast and easy method to isolate untouched human tumor cells from xenografted tumor tissue. This procedure is based on the comprehensive depletion of cells of mouse origin by combining automated tissue dissociation with the benchtop tissue dissociator and magnetic cell sorting. Here, we demonstrate that human target cells can be can be obtained with purities higher than 96% within less than 20 min independent of the tumor type.

Human tumor xenografts are vascularized and infiltrated by cells of mouse origin during the growth phase in vivo. To circumvent the bias caused by these contaminating cells during downstream analysis, we developed a method allowing for comprehensive depletion of all mouse cells by magnetic cell sorting.

El agotamiento de las células de ratón a partir de xenoinjertos de tumores humanos mejora significativamente análisis de aguas abajo de las células diana

The use of in vitro cell line models for cancer research has been a useful tool. However, it has been shown that these models fail to reliably mimic ...

Forskolin-induced Swelling in Intestinal Organoids: An In Vitro Assay for Assessing Drug Response in Cystic Fibrosis Patients

Recently-developed cystic fibrosis transmembrane conductance regulator (CFTR)-modulating drugs correct surface expression and/or function of the mutant CFTR channel in subjects with cystic fibrosis (CF). Identification of subjects that may benefit from these drugs is challenging because of the extensive heterogeneity of CFTR mutations, as well as other unknown factors that contribute to individual drug efficacy. Here, we describe a simple and relatively rapid assay for measuring individual CFTR function and response to CFTR modulators in vitro. Three dimensional (3D) epithelial organoids are grown from rectal biopsies in standard organoid medium. Once established, the organoids can be bio-banked for future analysis. For the assay, 30-80 organoids are seeded in 96-well plates in basement membrane matrix and are then exposed to drugs. One day later, the organoids are stained with calcein green, and forskolin-induced swelling is monitored by confocal live cell microscopy at 37 &#176;C. Forskolin-induced swelling is fully CFTR-dependent and is sufficiently sensitive and precise to allow for discrimination between the drug responses of individuals with different and even identical CFTR mutations. In vitro swell responses correlate with the clinical response to therapy. This assay provides a cost-effective approach for the identification of drug-responsive individuals, independent of their CFTR mutations. It may also be instrumental in the development of future CFTR modulators.

Forskolin-induced Swelling in Intestinal Organoids: An In Vitro Assay for Assessing Drug Response in Cystic Fibrosis Patients

This protocol describes an assay for measuring CFTR function and CFTR modulator responses in cultured tissue from subjects with cystic fibrosis (CF). Biopsy-derived intestinal organoids swell in a cAMP-driven fashion, a response that is defective (or strongly reduced) in CF organoids and can be restored by exposure to CFTR modulators.

Inducida por la forskolina Hinchazón en organoides intestinal: Una<em&gt; In Vitro</em&gt; Ensayo para evaluar la respuesta de drogas en pacientes con fibrosis quística

Recently-developed cystic fibrosis transmembrane conductance regulator (CFTR)-modulating drugs correct surface expression and/or function of the mutant ...

Preparation and In Vitro Characterization of Magnetized miR-modified Endothelial Cells

To date, the available surgical and pharmacological treatments for cardiovascular diseases (CVD) are limited and often palliative. At the same time, gene and cell therapies are highly promising alternative approaches for CVD treatment. However, the broad clinical application of gene therapy is greatly limited by the lack of suitable gene delivery systems. The development of appropriate gene delivery vectors can provide a solution to current challenges in cell therapy. In particular, existing drawbacks, such as limited efficiency and low cell retention in the injured organ, could be overcome by appropriate cell engineering (i.e., genetic) prior to transplantation. The presented protocol describes the efficient and safe transient modification of endothelial cells using a polyethyleneimine superparamagnetic magnetic nanoparticle (PEI/MNP)-based delivery vector. Also, the algorithm and methods for cell characterization are defined. The successful intracellular delivery of microRNA (miR) into human umbilical vein endothelial cells (HUVECs) has been achieved without affecting cell viability, functionality, or intercellular communication. Moreover, this approach was proven to cause a strong functional effect in introduced exogenous miR. Importantly, the application of this MNP-based vector ensures cell magnetization, with accompanying possibilities of magnetic targeting and non-invasive MRI tracing. This may provide a basis for magnetically guided, genetically engineered cell therapeutics that can be monitored non-invasively with MRI.

Preparation and In Vitro Characterization of Magnetized miR-modified Endothelial Cells

This manuscript describes the efficient, non-viral delivery of miR to endothelial cells by a PEI/MNP vector and their magnetization. Thus, in addition to genetic modification, this approach allows for magnetic cell guidance and MRI detectability. The technique can be used to improve the characteristics of therapeutic cell products.

Preparación y<em&gt; In Vitro</em&gt; Caracterización de Magnetized miR-modificado células endoteliales

To date, the available surgical and pharmacological treatments for cardiovascular diseases (CVD) are limited and often palliative. At the same time, gene ...

A Method for Quantifying Upper Limb Performance in Daily Life Using Accelerometers

A key reason for referral to rehabilitation services after stroke and other neurological conditions is to improve one's ability to function in daily life. It has become important to measure a person's activities in daily life, and not just measure their capacity for activity in the structured environment of a clinic or laboratory. A wearable sensor that is now enabling measurement of daily movement is the accelerometer. Accelerometers are commercially-available devices resembling large wrist watches that can be worn throughout the day. Data from accelerometers can quantify how the limbs are engaged to perform activities in peoples' homes and communities. This report describes a methodology to collect accelerometry data and turn it into clinically-relevant information. First, data are collected by having the participant wear two accelerometers (one on each wrist) for 24 h or longer. The accelerometry data are then downloaded and processed to produce four different variables that describe key aspects of upper limb activity in daily life: hours of use, use ratio, magnitude ratio, and the bilateral magnitude. Density plots can be constructed that visually represent the data from the 24 h wearing period. The variables and their resultant density plots are highly consistent in neurologically-intact, community-dwelling adults. This striking consistency makes them a useful tool for determining if upper limb daily performance is different from normal. This methodology is appropriate for research studies investigating upper limb dysfunction and interventions designed to improve upper limb performance in daily life in people with stroke and other patient populations. Because of its relative simplicity, it may not be long before it is also incorporated in clinical neurorehabilitation practice.

This protocol describes a method to quantify upper limb performance in daily life using wrist-worn accelerometers.

Un método para cuantificar Rendimiento de las extremidades superiores en la Vida Diaria El uso de acelerómetros

A key reason for referral to rehabilitation services after stroke and other neurological conditions is to improve one's ability to function in daily life. ...

An In Vitro Approach to Photodynamic Therapy

Photodynamic therapy (PDT) is a medical procedure that involves incubation of an exogenously applied photosensitizer (PS) followed by visible light photoactivation to induce cell apoptosis. The Federal Drug Administration has approved PDT for the treatment of actinic keratosis, and clinical guidelines recommend PDT as a treatment for certain non-melanoma skin cancers and acne vulgaris. PDT is an advantageous therapeutic modality as it is low cost, non-invasive, and associated with minimal adverse events and scaring. In the first step of PDT, a PS is applied and allowed to accumulate intracellularly. Subsequent light irradiation induces reactive oxygen species formation, which may ultimately lead to cell apoptosis, membrane disruption, mitochondrial damage, immune modulation, keratinocyte proliferation, and collagen turnover. Herein, we present an in vitro method to study PDT in an adherent cell line. This treatment protocol is designed to simulate PDT and may be adjusted to studying the use of PDT with various cell lines, photosensitizers, incubation temperatures, or photoactivation wavelengths. Squamous cell carcinoma cells were incubated with 0, 0.5, 1.0, and 2 mM 5-aminolevulinic acid (5-ALA) for 30 min and photoactivated with 417 nm blue light for 1,000 s. The primary outcome measure was apoptosis and necrosis, as measured by annexin-V and 7-aminoactinomycin D flow cytometry. There was a dose-dependent increase in cell apoptosis following thirty-minute incubation of 5-ALA. To achieve high inter-test validity, it is important to maintain consistent incubation and light parameters when performing in vitro PDT experiments. PDT is a useful clinical procedure and in vitro research may allow for the development of novel PSs, optimization of protocols, and new indications for PDT.

An In Vitro Approach to Photodynamic Therapy

Photodynamic therapy (PDT) is a medical procedure that involves incubation of an exogenously applied photosensitizer (PS) followed by visible light photoactivation to induce apoptosis. We present an in vitro PDT protocol designed to simulate PDT that may be used to study differences in PS incubation and light treatment parameters.

Un enfoque In Vitro de la terapia fotodinámica

Photodynamic therapy (PDT) is a medical procedure that involves incubation of an exogenously applied photosensitizer (PS) followed by visible light ...

Preparation Of Gushukang (GSK) Granules for In Vivo and In Vitro Experiments

Traditional Chinese herbal medicine plays a role as an alternative method in treating many diseases, such as postmenopausal osteoporosis (POP). Gushukang (GSK) granules, a marketed prescription in China, have bone-protective effects in treating POP. Before administration to the body, one standard preparation procedure is commonly required, which aims to promote the release of active constituents from raw herbs and enhance the pharmacological effects as well as therapeutic outcomes. This study proposes a detailed protocol for using GSK granules in in vivo and in vitro experimental assays. The authors first provide a detailed protocol to calculate the animal-appropriate dosages of granules for in vivo investigation: weighing, dissolving, storage, and administration. Second, this article describes protocols for micro-CT scanning and the measurement of bone parameters. Sample preparation, protocols for running the micro-CT machine and quantification of bone parameters were evaluated. Third, serum-containing GSK granules are prepared, and drug-containing serum is extracted for in vitro osteoclastogenesis and osteoblastogenesis. GSK granules were intragastrically administered twice per day to rats for three consecutive days. Blood was then collected, centrifuged, inactivated, and filtered. Finally, serum was diluted and used for performing osteoclastogenesis and osteoblastogenesis. The protocol described here can be considered a reference for pharmacological investigations of herbal prescription medicines, such as granules.

Preparation Of Gushukang GSK Granules for In Vivo and In Vitro Experiments

This article provides a detailed protocol for preparing a working solution of Gushukang granules for animal studies and GSK granule containing serum for in vitro experiments. This protocol can be applied to pharmacological investigations of herbal medicines as well as prescriptions for both in vivo and in vitro experiments.

Preparación de gránulos Gushukang (GSK) para experimentos in Vivo e In Vitro

Traditional Chinese herbal medicine plays a role as an alternative method in treating many diseases, such as postmenopausal osteoporosis (POP). Gushukang ...

Large Animal Model for Evaluating the Efficacy of the Gene Therapy in Ischemic Heart

Coronary artery disease is one of the significant causes of mortality and morbidity worldwide. Despite the progression of current therapeutics, a considerable proportion of coronary artery disease patients remain symptomatic. Gene therapy-mediated therapeutic angiogenesis offers a novel therapeutic method for improving myocardial perfusion and relieving symptoms. Gene therapy with different angiogenic factors has been studied in few clinical trials. Due to the novelty of the method, the progress of myocardial gene therapy is a continuous path from bench to bedside. Therefore, large animal models are needed for evaluating the safety and efficacy. The more the large animal model identifies the original disease and the endpoints used in clinics, the more predictable outcomes are from clinical trials. Here, we introduce a large animal model for evaluating the efficacy of the gene therapy in the ischemic porcine heart. We use clinically relevant imaging methods such as ultrasound imaging and 15H2O-PET. For targeting the gene transfers into the desired area, electroanatomical mapping is used. The aim of this method is: (1) to mimic chronic coronary artery disease, (2) to induce therapeutic angiogenesis at hypoxic areas of the heart, and (3) to evaluate the safety and efficacy of the gene therapy by using relevant endpoints.

Myocardial gene therapy for ischemic heart disease holds great promise for future therapeutics. Here, we introduce a large animal model for evaluating the efficacy of gene therapy in the ischemic heart.