Dataset Information

Tumor vascular microenvironment determines responsiveness to photodynamic therapy.

ABSTRACT: The efficacy of photodynamic therapy (PDT) depends upon the delivery of both photosensitizing drug and oxygen. In this study, we hypothesized that local vascular microenvironment is a determinant of tumor response to PDT. Tumor vascularization and its basement membrane (collagen) were studied as a function of supplementation with basement membrane matrix (Matrigel) at the time of tumor cell inoculation. Effects on vascular composition with consequences to tumor hypoxia, photosensitizer uptake, and PDT response were measured. Matrigel-supplemented tumors developed more normalized vasculature, composed of smaller and more uniformly spaced blood vessels than their unsupplemented counterparts, but these changes did not affect tumor oxygenation or PDT-mediated direct cytotoxicity. However, PDT-induced vascular damage increased in Matrigel-supplemented tumors, following an affinity of the photosensitizer Photofrin for collagen-containing vascular basement membrane coupled with increased collagen content in these tumors. The more highly collagenated tumors showed more vascular congestion and ischemia after PDT, along with a higher probability of curative outcome that was collagen dependent. In the presence of photosensitizer-collagen localization, PDT effects on collagen were evidenced by a decrease in its association with vessels. Together, our findings show that photosensitizer localization to collagen increases vascular damage and improves treatment efficacy in tumors with greater collagen content. The vascular basement membrane is thus identified to be a determinant of therapeutic outcome in PDT of tumors.

SUBMITTER: Maas AL

PROVIDER: S-EPMC3328659 | biostudies-literature | 2012 Apr

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Tumor vascular microenvironment determines responsiveness to photodynamic therapy.

Maas Amanda L AL Carter Shirron L SL Wileyto E Paul EP Miller Joann J Yuan Min M Yu Guoqiang G Durham Amy C AC Busch Theresa M TM

Cancer research 20120228 8

The efficacy of photodynamic therapy (PDT) depends upon the delivery of both photosensitizing drug and oxygen. In this study, we hypothesized that local vascular microenvironment is a determinant of tumor response to PDT. Tumor vascularization and its basement membrane (collagen) were studied as a function of supplementation with basement membrane matrix (Matrigel) at the time of tumor cell inoculation. Effects on vascular composition with consequences to tumor hypoxia, photosensitizer uptake, a ...[more]

PMID: 22374982

Similar Datasets

Project description:Background: To investigate the efficacy of a PLGA-based nanobody complex in photodynamic therapy (PDT) and NIR-II imaging in A549 tumor hypoxic model.Method: IR1048-MZ was firstly synthesized by conjugating a nitro imidazole group to IR1048. IR1048-MZ and Cat were then encapsulated in PLGA-SH solution. Anti-EGFR-Nanobody was also expressed and purified, and finally Anti-EGFR-Nanobody@PLGA-IR1048MZ-Cat (Nb@IC-NPs) nanobody complex was obtained based on the formation of desulfide bond between PLGA-SH and Anti-EGFR-Nanobody. Size distribution and morphology were characterized by TEM and DLS. Spectrum of Nb@IC-NPs towards NTR was measured by UV and fluorescence, while the particle's selective response was studied using fluorescence. The uptake of Nb@IC-NPs in A549 cells was observed by flow cytometry and CLSM. In the meantime, its' catalytic ability that decomposes H2O2 both extra-and intra-cellular was observed by fluorescence and CLSM. In vitro photodynamic toxicity of Nb@IC-NPs was examined by MTT, Live/Dead Cell Staining, Flow Cytometry and Apoptosis Assay. Tumor-bearing model was constructed to observe a semi-quantitative fluorescent distribution and the possibility of NIR-II fluorescence/photoacoustic (PA) imaging. Effect of Nb@IC-NPs on enhancing A549 tumor hypoxia and expression profile of HIF-1? was investigated in the presence of NIR. An A549 tumor metastasis model was also constructed to confirm the complex' potential to destroy primary tumor, inhibit lung metastasis, and prolong mice' survival. Lastly, impact of Nb@IC-NPs on mice' main organs and blood indices was observed.Results: Nb@IC-NPs was successfully fabricated with good homogeneity. The fluorescent absorbance of Nb@IC-NPs showed a linear relationship with the concentration of NTR, and a higher concentration of NTR corresponded to a stronger photoacoustic signal. In addition, Nb@IC-NPs showed a stable selectivity toward NTR. Our results also suggested a high efficient uptake of Nb@IC-NPs in A549 cells, which was more efficient than IC-NPs and IR1048-MZ alone. In vitro assays confirmed the effects of Nb@IC-NPs on catalytic O2 generation even in hypoxic cells. The cell viability was upregulated with the nanocomplex at the absence of the laser, whereas it was dramatically declined with laser treatment that excited at 980 nm. Nb@IC-NPs achieved tumor hypoxia NIR-II/PA imaging through assisting A549 gathering. When NIR was applied, Nb@IC-NPs can significantly relieve A549 cellular/tumor hypoxia by generating more reactive oxygen species (ROS), which in turn helps lower the expression level of HIF-1?. In summary, Nb@IC-NPs based PDT can efficiently decimate A549 primary tumor, inhibit metastatic lung cancer, and prolong the lifespan of the mice under tolerable dosage. At last, in vivo toxicity tests of the nanocomplex showed its biosafety to the main organs and normal blood indices values.Conclusion: Nb@IC-NPs improves tumor hypoxia through catalytic reaction and lowers the expression level of HIF-1?. It achieves tumor PA imaging through intensified NIR-II fluorescence signal that caused by response of the complex to the lesion's nitroreductase (NTR). Nb@IC-NPs based PDT can efficiently kill A549 primary tumor, inhibit a lung metastasis, as well as prolong mice' survival cycle.

Project description:The low tissue penetration depth of external excitation light severely hinders the sensitivity of fluorescence imaging (FL) and the efficacy of photodynamic therapy (PDT) in vivo; thus, rational theranostic platforms that overcome the light penetration depth limit are urgently needed. To overcome this crucial problem, we designed a self-luminescing nanosystem (denoted POCL) with near-infrared (NIR) light emission and singlet oxygen (1O2) generation abilities utilizing an intraparticle relayed resonance energy transfer strategy. Methods: Bis[3,4,6-trichloro-2-(pentyloxycarbonyl) phenyl] oxalate (CPPO) as a chemical energy source with high reactivity toward H2O2, poly[(9,9'-dioctyl-2,7-divinylene-fluorenylene)-alt-2-methoxy- 5-(2-ethyl-hexyloxy)-1,4-phenylene] (PFPV) as a highly efficient chemiluminescence converter, and tetraphenylporphyrin (TPP) as a photosensitizer with NIR emission and 1O2 generation abilities were coencapsulated by self-assembly with poly(ethyleneglycol)-co-poly(caprolactone) (PEG-PCL) and folate-PEG-cholesterol to form the POCL nanoreactor, with folate as the targeting group. A series of in vitro and in vivo analyses, including physical and chemical characterizations, tumor targeting ability, tumor microenvironment activated imaging and photodynamic therapy, as well as biosafety, were systematically investigated to characterize the POCL. Results: The POCL displayed excellent NIR luminescence and 1O2 generation abilities in response to H2O2. Therefore, it could serve as a specific H2O2 probe to identify tumors through chemiluminescence imaging and as a chemiluminescence-driven PDT agent for inducing tumor cell apoptosis to inhibit tumor growth due to the abnormal overproduction of H2O2 in the tumor microenvironment. Moreover, the folate ligand on the POCL surface can further improve the accumulation at the tumor site via a receptor-mediated mechanism, thus enhancing tumor imaging and the therapeutic effects both in vitro and in vivo but without any observable systemic toxicity. Conclusion: The nanosystem reported here might serve as a targeted, smart, precise, and noninvasive strategy triggered by the tumor microenvironment rather than by an outside light source for cancer NIR imaging and PDT treatment without limitations on penetration depth.

Dataset Information

Tumor vascular microenvironment determines responsiveness to photodynamic therapy.

Publications

Tumor vascular microenvironment determines responsiveness to photodynamic therapy.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure