This research is funded by an operating grant from the Canadian Institutes of Health Research (CIHR) to C.A. and D.A.J. The authors acknowledge the Canadian Foundation for Innovation and Princess Margaret Cancer Foundation for funding the STTARR research facility that enables the imaging and therapy research components of this work.

1. Liposome Preparation
<ol>
	<li>Dissolve the lipids 1,2-Dipalmitoyl-sn-glycero-3-phosphocholine (DPPC), 1-stearoyl-2-hydroxy-sn-glycero-3-phosphatidylcholine (MSPC or S-lyso-PC) and N-(carbonyl-methoxypolyethyleneglycol 2000)-1,2-distearoyl-sn-glycero-3-phosphoethanolamine (mPEG2000-DSPE) in chloroform. For example, for preparation of 10 ml of HTLC, weigh out 314.4 mg DPPC, 39.4 mg MSPC, and 83.9 mg mPEG2000-DSPE into an amber glass vial. Then, dissolve the l...

<ol>
	<li>Maeda, H., Wu, J., Sawa, T., Matsumura, Y., Hori, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Tumor+vascular+permeability+and+the+EPR+effect+in+macromolecular+therapeutics:+a+review.">Tumor vascular permeability and the EPR effect in macromolecular therapeutics: a review.</a> J Control Releas. 65 (1-2), 271-284 (2000).</li><li>Simard, P., Leroux, J. C., Allen, C., Meyer, O. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Liposomes+for+Drug+Delivery.">Liposomes for Drug Delivery.</a> Nanoparticles for Pharmaceutical Application. , (2007).</li><li>O'Brien, M. E. R., 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=Reduced+cardiotoxicity+and+comparable+efficacy+in+a+phase+III+trial+of+pegylated+liposomal+doxorubicin+HCl+(CAELYX+(TM)/Doxil+(R))+versus+conventional+doxorubicin+for+first-line+treatment+of+metastatic+breast+cancer.">Reduced cardiotoxicity and comparable efficacy in a phase III trial of pegylated liposomal doxorubicin HCl (CAELYX (TM)/Doxil (R)) versus conventional doxorubicin for first-line treatment of metastatic breast cancer.</a> Ann Onco. 15 (3), 440-449 (2004).</li><li>White, S. 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=Phase+II+study+of+SPI-77+(sterically+stabilised+liposomal+cisplatin)+in+advanced+non-small-cell+lung+cancer.">Phase II study of SPI-77 (sterically stabilised liposomal cisplatin) in advanced non-small-cell lung cancer.</a> Br J Cancer. 95 (7), 822-828 (2006).</li><li>Laginha, K. M., Verwoert, S., Charrois, G. J. R., Allen, T. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Determination+of+doxorubicin+levels+in+whole+tumor+and+tumor+nuclei+in+murine+breast+cancer+tumors.">Determination of doxorubicin levels in whole tumor and tumor nuclei in murine breast cancer tumors.</a> Clin Cancer Res. 11 (19), 6944-6949 (2005).</li><li>Baronzio, G. F., Hager, E. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Hyperthermia in cancer treatment: a primer. , (2006).</li><li>Landon, C. D., Park, J. Y., Needham, D., Dewhirst, M. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Nanoscale+Drug+Delivery+and+Hyperthermia:+The+Materials+Design+and+Preclinical+and+Clinical+Testing+of+Low+Temperature-Sensitive+Liposomes+Used+in+Combination+with+Mild+Hyperthermia+in+the+Treatment+of+Local+Cancer.">Nanoscale Drug Delivery and Hyperthermia: The Materials Design and Preclinical and Clinical Testing of Low Temperature-Sensitive Liposomes Used in Combination with Mild Hyperthermia in the Treatment of Local Cancer.</a> Open Nanomed. 3, 38-64 (2011).</li><li>Koning, G. A., Eggermont, A. M., Lindner, L. H., ten Hagen, T. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Hyperthermia+and+thermosensitive+liposomes+for+improved+delivery+of+chemotherapeutic+drugs+to+solid+tumors.">Hyperthermia and thermosensitive liposomes for improved delivery of chemotherapeutic drugs to solid tumors.</a> Pharm Res. 27 (8), 1750-1754 (2010).</li><li>Viglianti, B. 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=In+vivo+monitoring+of+tissue+pharmacokinetics+of+liposome/drug+using+MRI:+illustration+of+targeted+delivery.">In vivo monitoring of tissue pharmacokinetics of liposome/drug using MRI: illustration of targeted delivery.</a> Magn Reson Me. 51 (6), 1153-1162 (2004).</li><li>Ponce, A. 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=Magnetic+resonance+imaging+of+temperature-sensitive+liposome+release:+drug+dose+painting+and+antitumor+effects.">Magnetic resonance imaging of temperature-sensitive liposome release: drug dose painting and antitumor effects.</a> J Natl Cancer Ins. 99 (1), 53-63 (2007).</li><li>Kong, 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=Efficacy+of+liposomes+and+hyperthermia+in+a+human+tumor+xenograft+model:+importance+of+triggered+drug+release.">Efficacy of liposomes and hyperthermia in a human tumor xenograft model: importance of triggered drug release.</a> Cancer Res. 60 (24), 6950-6957 (2000).</li><li>Yarmolenko, P. 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=Comparative+effects+of+thermosensitive+doxorubicin-containing+liposomes+and+hyperthermia+in+human+and+murine+tumours.">Comparative effects of thermosensitive doxorubicin-containing liposomes and hyperthermia in human and murine tumours.</a> Int J Hyperthermia. 26 (5), 485-498 (2010).</li><li>Wang, L. H., Jacques, S. L., Zheng, L. Q. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=MCML-Monte+Carlo+modeling+of+photon+transport+in+multi-layered+tissues.">MCML-Monte Carlo modeling of photon transport in multi-layered tissues.</a> Comput Meth Prog Bio. 47, 131-146 (1995).</li><li>Rieke, V., Butts Pauly, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=MR+thermometry.">MR thermometry.</a> J Magn Reson Imaging. 27 (2), 376-390 (2008).</li><li>Dou, Y. N., 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=Heat-activated+thermosensitive+liposomal+cisplatin+(HTLC)+results+in+effective+growth+delay+of+cervical+carcinoma+in+mice.">Heat-activated thermosensitive liposomal cisplatin (HTLC) results in effective growth delay of cervical carcinoma in mice.</a> J Control Release. 178, 69-78 (2014).</li><li>Lammers, T., Kiessling, F., Hennink, W. E., Storm, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Nanotheranostics+and+image-guided+drug+delivery:+current+concepts+and+future+directions.">Nanotheranostics and image-guided drug delivery: current concepts and future directions.</a> Mol Pharm. 7 (6), 1899-1912 (2010).</li><li>Lee, 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=A+novel+64Cu-liposomal+PET+agent+(MM-DX-929)+predicts+response+to+liposomal+chemotherapeutics+in+preclinical+breast+cancer+models.">A novel 64Cu-liposomal PET agent (MM-DX-929) predicts response to liposomal chemotherapeutics in preclinical breast cancer models.</a> Thirty-Fifth Annual CTRC-AACR San Antonio Breast Cancer Symposium. , (2012).</li></ol>

Liposomes were first developed in the 1960s as drug delivery vehicles that carry hydrophilic drugs in their internal aqueous volume and hydrophobic drugs within their lipid bilayer2. In addition to use in therapeutic applications, liposomes have been explored for diagnostic applications when labeled with radionuclides or loaded with imaging contrast agents17. In recent years, theranostics and therapeutic-diagnostic pairs have been pursued to provide opportunities for image-guided patient stratificat...

The pathophysiology of solid tumors results in the enhanced permeability and retention (EPR) of nanoscale systems. This has led to the development of many drug delivery systems that take advantage of this effect to target the tumor tissue while minimizing systemic side effects1. Liposomal delivery technologies have been widely investigated for drug or imaging probes2. Although liposomes have significantly reduced the systemic toxicity compared to conventional chemotherapy, there have been few improvements in clinical efficacy3,4. Studies have shown that the limited efficacy is due to a lack of drug release from the carrier4,5. As a result, development of liposomes that are activated to release the encapsulated drug in response to external stimuli has attracted considerable attention. Hyperthermia has been employed for decades as a relatively safe treatment modality for cancer patients6. Therefore the development of thermosensitive liposomes with heat as an external trigger has been a logical combination with significant potential for clinical translation. Indeed, the lysolipid-containing thermosensitive liposome formulation of doxorubicin, known as LTSL-DOX, has now reached clinical evaluation7.
Recent clinical data with LTSL-DOX has shown that the protocol for heat delivery is a critical factor that can heavily influence patient outcomes8. In humans, radiofrequency, microwave, laser and ultrasound transducers are used to apply hyperthermia locally at tumor sites9. In preclinical studies requiring heating of subcutaneous tumors, heating catheters10,11 and water baths12,13 are most often employed. In this manuscript, we introduce a new method for heating subcutaneous tumors using a custom designed laser-based heating setup, which enables more conformal heating of the tumor volume.&#160;Using MR compatible materials, the setup is small enough to fit within the bore of a small animal MR imager, allowing real time monitoring of changes in tissue temperature during the laser heating.
The MR contrast agent, gadoteridol (Gd-HP-DO3A), was co-encapsulated with CDDP into a thermosensitive liposome formulation of CDDP (HTLC), known as Gd-HTLC, for real-time MR image-guided monitoring and assessment of heat-activated drug release and validation of the heating protocol. Our results demonstrate that the laser-based heating apparatus efficiently activated the release of encapsulated agents from the Gd-HTLC formulation while being monitored through MR imaging.

<table border="0" cellpadding="0" cellspacing="0">
	<tbody>
		<tr>
			<td>Rotary evaporator</td>
			<td>Heidolph Instruments GmbH &#38; Co.KG</td>
			<td>Laborota 4000</td>
			<td></td>
		</tr>
		<tr>
			<td>High pressure extruder</td>
			<td>Northern Lipids Inc.</td>
			<td>T.001</td>
			<td>10 mL thermobarrel</td>
		</tr>
		<tr>
			<td>Heating circulator</td>
			<td>VWR International LLC.</td>
			<td>11305</td>
			<td>Connected to extruder</td>
		</tr>
		<tr>
			<td>Polycarbonate membrane filter</td>
			<td>Whatman</td>
			<td>110605;110606</td>
			<td></td>
		</tr>
		<tr>
			<td>Differential scanning calorimeter (DSC)</td>
			<td>TA Instruments</td>
			<td>Q100</td>
			<td></td>
		</tr>
		<tr>
			<td>Inductively coupled plasma-atomic emission spectrometer (ICP-AES)</td>
			<td>PerkinElmer</td>
			<td>Optima 7300DV</td>
			<td></td>
		</tr>
		<tr>
			<td>Zetasizer</td>
			<td>Malvern Instruments Ltd.</td>
			<td>Nano-ZS</td>
			<td></td>
		</tr>
		<tr>
			<td>Cell incubator</td>
			<td>NuAire Inc.</td>
			<td>NU-5800</td>
			<td></td>
		</tr>
		<tr>
			<td>Autoclip wound clip applier</td>
			<td>Becton Dickinson</td>
			<td>427630</td>
			<td></td>
		</tr>
		<tr>
			<td>Autoclip wound clip remover</td>
			<td>Becton Dickinson</td>
			<td>427637</td>
			<td></td>
		</tr>
		<tr>
			<td>Wound clips</td>
			<td>Becton Dickinson</td>
			<td>427631</td>
			<td>9 mm</td>
		</tr>
		<tr>
			<td>763 nm Laser device</td>
			<td>Biolitec</td>
			<td>Ceralas CD 403 laser</td>
			<td></td>
		</tr>
		<tr>
			<td>Laser probe</td>
			<td>Thorlabs Inc.</td>
			<td>FT400EMT</td>
			<td>With SMA and flat cleave connectors</td>
		</tr>
		<tr>
			<td>Spectralon (illuminator)</td>
			<td>Labsphere Inc.</td>
			<td>FAST-SL-5CMX5CM</td>
			<td></td>
		</tr>
		<tr>
			<td></td>
			<td></td>
			<td>CSTM-SL-5CMX5CM</td>
			<td></td>
		</tr>
		<tr>
			<td>7 Tesla prelinical magnetic resonance (MR) imaging system</td>
			<td>Bruker Corporation</td>
			<td>Biospec 70/30</td>
			<td></td>
		</tr>
		<tr>
			<td>Fiber optic temperature sensor</td>
			<td>LumaSense Technologies Inc.</td>
			<td>Luxtron FOT Lab Kit</td>
			<td></td>
		</tr>
		<tr>
			<td>Integrating sphere</td>
			<td>Newport Corporation</td>
			<td>819C</td>
			<td></td>
		</tr>
		<tr>
			<td>Optical power meter</td>
			<td>Newport Corporation</td>
			<td>1830-R</td>
			<td></td>
		</tr>
	</tbody>
</table>

custom-designed laser-based heating apparatus for triggered release of cisplatin from thermosensitive liposomes with magnetic resonance image guidance

Liposomes have been employed as drug delivery systems to target solid tumors through exploitation of the enhanced permeability and retention (EPR) effect resulting in significant reductions in systemic toxicity. Nonetheless, insufficient release of encapsulated drug from liposomes has limited their clinical efficacy. Temperature-sensitive liposomes have been engineered to provide site-specific release of drug in order to overcome the problem of limited tumor drug bioavailability. Our lab has designed and developed a heat-activated thermosensitive liposome formulation of cisplatin (CDDP), known as HTLC, to provide triggered release of CDDP at solid tumors. Heat-activated delivery in vivo was achieved in murine models using a custom-built laser-based heating apparatus that provides a conformal heating pattern at the tumor site as confirmed by MR thermometry (MRT). A fiber optic temperature monitoring device was used to measure the temperature in real-time during the entire heating period with online adjustment of heat delivery by alternating the laser power. Drug delivery was optimized under magnetic resonance (MR) image guidance by co-encapsulation of an MR contrast agent (i.e.,&#160;gadoteridol) along with CDDP into the thermosensitive liposomes as a means to validate the heating protocol and to assess tumor accumulation. The heating protocol consisted of a preheating period of 5 min prior to administration of HTLC and 20 min heating post-injection. This heating protocol resulted in effective release of the encapsulated agents with the highest MR signal change observed in the heated tumor in comparison to the unheated tumor and muscle. This study demonstrated the successful application of the laser-based heating apparatus for preclinical thermosensitive liposome development and the importance of MR-guided validation of the heating protocol for optimization of drug delivery.

The HTLC liposomes are manufactured using common methods, including lipid film formation, hydration, extrusion and dialysis. During steps involving CDDP, caution should be taken not to expose CDDP to any aluminum material, as CDDP will be deactivated through the formation of a black deposit. An illustration of HTLC is shown in Figure 3. The physico-chemical properties of HTLC were summarized in a manuscript recently published in the Journal of Controlled Release16. The gadolinium and ...

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Custom-designed Laser-based Heating Apparatus for Triggered Release of Cisplatin from Thermosensitive Liposomes with Magnetic Resonance Image Guidance

AN MRI-compatible&#160;custom-designed laser-based heating apparatus has been developed to provide local heating of subcutaneous tumors in order to activate release of agents from thermosensitive liposomes specifically at the tumor region.

Liposomes have been employed as drug delivery systems to target solid tumors through exploitation of the enhanced permeability and retention (EPR) effect ...

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Bioengineering

8.9K 조회수.  University of Toronto.  MRI 호환 주문 설계된 레이저 기반의 가열 장치는 특히 종양 영역에서 감온 리포좀 제제로부터의 방출을 활성화하기 위해 피하 종양 국소 가열을 제공하기 위해 개발되었다. 

비디오: Custom-designed Laser-based Heating Apparatus for Triggered Release of Cisplatin from Thermosensitive Liposomes with Magnetic Resonance Image Guidance