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Sine J, Urban C, Thayer D, Charron H, Valim N, Tata DB, Schiff R, Blumenthal R, Joshi A, Puri A. Photo activation of HPPH encapsulated in "Pocket" liposomes triggers multiple drug release and tumor cell killing in mouse breast cancer xenografts. Int J Nanomedicine 2014; 10:125-45. [PMID: 25565809 PMCID: PMC4278788 DOI: 10.2147/ijn.s72143] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
We recently reported laser-triggered release of photosensitive compounds from liposomes containing dipalmitoylphosphatidylcholine (DPPC) and 1,2 bis(tricosa-10,12-diynoyl)-sn-glycero-3-phosphocholine (DC(8,9)PC). We hypothesized that the permeation of photoactivated compounds occurs through domains of enhanced fluidity in the liposome membrane and have thus called them "Pocket" liposomes. In this study we have encapsulated the red light activatable anticancer photodynamic therapy drug 2-(1-Hexyloxyethyl)-2-devinyl pyropheophorbide-a (HPPH) (Ex/Em410/670 nm) together with calcein (Ex/Em490/517 nm) as a marker for drug release in Pocket liposomes. A mole ratio of 7.6:1 lipid:HPPH was found to be optimal, with >80% of HPPH being included in the liposomes. Exposure of liposomes with a cw-diode 660 nm laser (90 mW, 0-5 minutes) resulted in calcein release only when HPPH was included in the liposomes. Further analysis of the quenching ratios of liposome-entrapped calcein in the laser treated samples indicated that the laser-triggered release occurred via the graded mechanism. In vitro studies with MDA-MB-231-LM2 breast cancer cell line showed significant cell killing upon treatment of cell-liposome suspensions with the laser. To assess in vivo efficacy, we implanted MDA-MB-231-LM2 cells containing the luciferase gene along the mammary fat pads on the ribcage of mice. For biodistribution experiments, trace amounts of a near infrared lipid probe DiR (Ex/Em745/840 nm) were included in the liposomes. Liposomes were injected intravenously and laser treatments (90 mW, 0.9 cm diameter, for an exposure duration ranging from 5-8 minutes) were done 4 hours postinjection (only one tumor per mouse was treated, keeping the second flank tumor as control). Calcein release occurred as indicated by an increase in calcein fluorescence from laser treated tumors only. The animals were observed for up to 15 days postinjection and tumor volume and luciferase expression was measured. A significant decrease in luciferase expression and reduction in tumor volume was observed only in laser treated animal groups injected with liposomes containing HPPH. Histopathological examination of tumor tissues indicated tumor necrosis resulting from laser treatment of the HPPH-encapsulated liposomes that were taken up into the tumor area.
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Affiliation(s)
- Jessica Sine
- Membrane Structure and Function Section, Basic Research Laboratory, Center for Cancer Research, National Cancer Institute - Frederick, Frederick, MD, USA
| | - Cordula Urban
- Department of Radiology, Baylor College of Medicine, Houston, TX, USA
| | - Derek Thayer
- Membrane Structure and Function Section, Basic Research Laboratory, Center for Cancer Research, National Cancer Institute - Frederick, Frederick, MD, USA
| | - Heather Charron
- Department of Radiology, Baylor College of Medicine, Houston, TX, USA
| | - Niksa Valim
- Department of Radiology, Baylor College of Medicine, Houston, TX, USA
| | - Darrell B Tata
- US Food and Drug Administration, CDRH/OSEL/Division of Physics, White Oak Campus, MD, USA
| | - Rachel Schiff
- Lester and Sue Smith Breast Center, Baylor College of Medicine, Houston, TX, USA
| | - Robert Blumenthal
- Membrane Structure and Function Section, Basic Research Laboratory, Center for Cancer Research, National Cancer Institute - Frederick, Frederick, MD, USA
| | - Amit Joshi
- Department of Radiology, Baylor College of Medicine, Houston, TX, USA
| | - Anu Puri
- Membrane Structure and Function Section, Basic Research Laboratory, Center for Cancer Research, National Cancer Institute - Frederick, Frederick, MD, USA
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Baba K, Pudavar HE, Roy I, Ohulchanskyy TY, Chen Y, Pandey R, Prasad PN. New method for delivering a hydrophobic drug for photodynamic therapy using pure nanocrystal form of the drug. Mol Pharm 2007; 4:289-97. [PMID: 17266331 PMCID: PMC2667689 DOI: 10.1021/mp060117f] [Citation(s) in RCA: 88] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A carrier-free method for delivery of a hydrophobic drug in its pure form, using nanocrystals (nanosized crystals), is proposed. To demonstrate this technique, nanocrystals of a hydrophobic photosensitizing anticancer drug, 2-devinyl-2-(1-hexyloxyethyl)pyropheophorbide (HPPH), have been synthesized using the reprecipitation method. The resulting drug nanocrystals were monodispersed and stable in aqueous dispersion, without the necessity of an additional stabilizer (surfactant). As shown by confocal microscopy, these pure drug nanocrystals were taken up by the cancer cells with high avidity. Though the fluorescence and photodynamic activity of the drug were substantially quenched in the form of nanocrystals in aqueous suspension, both these characteristics were recovered under in vitro and in vivo conditions. This recovery of drug activity and fluorescence is possibly due to the interaction of nanocrystals with serum albumin, resulting in conversion of the drug nanocrystals into the molecular form. This was confirmed by demonstrating similar recovery in presence of fetal bovine serum (FBS) or bovine serum albumin (BSA). Under similar treatment conditions, the HPPH in nanocrystal form or in 1% Tween-80/water formulation showed comparable in vitro and in vivo efficacy.
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Affiliation(s)
- Koichi Baba
- Institute for Lasers, Photonics and Biophotonics, SUNY at Buffalo, Buffalo, New York 14260
| | - Haridas E. Pudavar
- Institute for Lasers, Photonics and Biophotonics, SUNY at Buffalo, Buffalo, New York 14260
| | - Indrajit Roy
- Institute for Lasers, Photonics and Biophotonics, SUNY at Buffalo, Buffalo, New York 14260
| | - Tymish Y. Ohulchanskyy
- Institute for Lasers, Photonics and Biophotonics, SUNY at Buffalo, Buffalo, New York 14260
| | - Yihui Chen
- Photodynamic Therapy Center, Roswell Park Cancer Institute, Buffalo, New York 14263
| | - Ravindra Pandey
- Photodynamic Therapy Center, Roswell Park Cancer Institute, Buffalo, New York 14263
| | - Paras N. Prasad
- Institute for Lasers, Photonics and Biophotonics, SUNY at Buffalo, Buffalo, New York 14260
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