Anticancer Drug Doxorubicin Spontaneously Reacts with GTP and dGTP.

Here, we reported a spontaneous reaction between anticancer drug doxorubicin and GTP or dGTP. Incubation of doxorubicin with GTP or dGTP at 37 °C or above yields a covalent product: the doxorubicin-GTP or -dGTP conjugate where a covalent bond is formed between the C14 position of doxorubicin and the 2-amino group of guanine. Density functional theory calculations show the feasibility of this spontaneous reaction. Fluorescence imaging studies demonstrate that the doxorubicin-GTP and -dGTP conjugates cannot enter nuclei although they rapidly accumulate in human SK-OV-3 and NCI/ADR-RES cells. Consequently, the doxorubicin-GTP and -dGTP conjugates are less cytotoxic than doxorubicin. We also demonstrate that doxorubicin binds to ATP, GTP, and other nucleotides with a dissociation constant (Kd) in the sub-millimolar range. Since human cells contain millimolar levels of ATP and GTP, these results suggest that doxorubicin may target ATP and GTP, energy molecules that support essential processes in living organisms.

Radiomicrosphere Dosimetry: Principles and Current State of the Art.

Radiomicrosphere Therapy (RMT) refers to a liver-directed therapeutic modality based on the intrahepatic arterial administration of radiolabeled microspheres. There is a need for standardization of the terminology of RMT. A descriptive identifier should first name the radioisotope, then the chemical formulation of the microsphere, and lastly add the term RMT that indicates the therapeutic modality. At present, clinically available options include |Y-90| |Resin| |RMT|, |Y-90| |Glass| |RMT| and |Ho-166| |PLLA| |RMT|. The latter is available in Europe and is being considered for clearance by the FDA in the United States. Preclinical studies with |Re-188| |PLLA| |RMT| are underway. Dosimetric considerations are strongly tied to both the type of the radioisotope and the chemical composition of the microsphere type. This review will focus on Y-90 resin and glass RMT, the history, dosimetry, clinical use, and controversies.

Computational model of silica nanoparticle penetration into tumor spheroids: Effects of methoxy and carboxy PEG surface functionalization and hyperthermia.

Drug delivery to tumors suffers from poor solubility, specificity, diffusion through the tumor micro-environment and nonoptimal interactions with components of the extracellular matrix and cell surface receptors. Nanoparticles and drug-polymer complexes address many of these problems. However, large size exasperates the problem of slow diffusion through the tumor. Three-dimensional tumor spheroids are good models to evaluate approaches to mitigate these difficulties and aid in design strategies to improve the delivery of drugs to treat cancer effectively. Diffusion of drug carriers is highly dependent on cell uptake rate parameters (association/dissociation) and temperature. Hyperthermia increases molecular transport and is known to act synergistically with chemotherapy to improve treatment. This study presents a new inverse estimation approach based on Bayesian probability for estimating nanoparticle cell uptake rates from experiments. The parameters were combined with a finite element computational model of nanoparticle transport under hyperthermia conditions to explore its effect on tumor porosity, diffusion and particle binding (association and dissociation) at cell surfaces. Carboxy-PEG-silane (cPEGSi) nanoparticles showed higher cell uptake compared to methoxy-PEG-silane (mPEGSi) nanoparticles. Simulations were consistent with experimental results from Skov-3 ovarian cancer spheroids. Amorphous silica (cPEGSi) nanoparticles (58 nm) concentrated at the periphery of the tumor spheroids at 37°C but mild hyperthermia (43°C) increased nanoparticle penetration. Thus, hyperthermia may enhance cancer treatment by improving blood delivery to tumors, enhancing extravasation and penetration into tumors, trigger release of drug from the carrier at the tumor site and possibly lead to synergistic anti-cancer activity with the drug.

Perspectives on the Future of Nanomedicine to Impact Patients: An Analysis of US Federal Funding and Interventional Clinical Trials.

The US and governments around the world, and companies, have made a considerable investment in nanomedicine, and there have been important discoveries. Nevertheless, there has been considerable debate as to whether the investment, both in money and in time, has been worth it. That question is not yet definitively answerable. However, investigators (and investors) might also wonder if the efforts in nanomedicine are likely to continue at the same pace as over the past decade. For this paper, an analysis was done by searching Medline, RePORT, the DOD (CDMRP), the NSF, and ClinicalTrials.gov. The major findings from the analysis are as follows: (1) The number of journal articles on the subject of nanomedicine continues to steadily rise and the areas "Drug Carriers" and "Drug Delivery Systems" are experiencing particularly rapid growth. (2) The level of funding from the Department of Health and Human Services (NIH and others) for indications other than cancer has been greater than that for cancer. (3) Funding for applications in HIV/AIDS has been strong. (4) Most of the cancers are being impacted. (5) The number of clinical trials are more highly focused in breast, skin, metastatic, and ovarian cancers, though the noncancer indications of pain and infections are also highly represented. The trials are primarily in Phases I and II, suggesting a long horizon before translating to a high impact on patients. (6) The vast majority of the clinical trials are for the evaluation of established nanomedicine formulations (liposomes and nab-paclitaxel/Abraxane) in combination with other therapies. Nevertheless, the number of clinical trials with other nanomedicine formulations has been increasing since 2009. Relatively few of the trials are for micelles or dendrimers. Taken as a whole, the analysis provides a picture that nanomedicine continues to be highly funded and highly studied but with few recent breakthroughs. Nanomedicine has yet to provide the "silver bullet" for therapy in cancer or other diseases, and it remains unclear whether it ever will.

Recalcitrant Issues and New Frontiers in Nano-Pharmacology.

Packaging of old pharma drugs into new packaging "nanoparticles" is called nano-pharmacology and the products are called nano-based drugs. The inception of nano-pharmacology research and development (R&D) is marked by the approval of the first nano-based drug Doxil® in 1995 by the Food and Drug Administration. However, even after more than two decades, today, there are only ∼20 nano-based drugs in the market to treat cancers and brain diseases. In this article we share the perspectives of nanotechnology scientists, engineers, and clinicians on the roadblocks in nano-pharmacology R&D. Also, we share our opinion on new frontiers in the field of nano-pharmacology R&D that may allow rapid and efficient transfer of nano-pharma technologies from R&D to market.

90 Y SPECT/CT quantitative study and comparison of uptake with pretreatment 99 m Tc-MAA SPECT/CT in radiomicrosphere therapy.

INTRODUCTION: Yttrium-90 (90 Y) microsphere post-treatment imaging reflects the true distribution characteristics of microspheres in the tumor and liver compartments. However, due to its decay spectra profile lacking a pronounced photopeak, the bremsstrahlung imaging for 90 Y has inherent limitations. The absorbed dose calculations for 90 Y microspheres radiomicrosphere therapy (RMT) sustain a limitation due to the poor quality of 90 Y imaging. The aim of this study was to develop quantitative methods to improve the post-treatment 90 Y bremsstrahlung single photon emission tomography (SPECT)/computed tomography (CT) image analysis for dosimetric purposes and to perform a quantitative comparison with the 99m Tc-MAA SPECT/CT images, which is used for theranostics purposes for liver and tumor dosimetry. METHODS: Pre and post-treatment SPECT/CT data of patients who underwent RMT for primary or metastatic liver cancer were acquired. A Jasczak phantom with eight spherical inserts of various sizes was used to obtain optimal iteration number for the contrast recovery algorithm for improving 90 Y bremsstrahlung SPECT/CT images. Comparison of uptake on 99m Tc-MAA and 90 Y microsphere SPECT/CT images was assessed using tumor to healthy liver ratios (TLRs). The voxel dosimetry technique was used to estimate absorbed doses. Absorbed doses within the tumor and healthy part of the liver were also investigated for correlation with administered activity. RESULTS: Improvement in CNR and contrast recovery coefficients on patient and phantom 90 Y bremsstrahlung SPECT/CT images respectively were achieved. The 99m Tc-MAA and 90 Y microspheres SPECT/CT images showed significant uptake correlation (r = 0.9, P = 0.05) with mean TLR of 9.4 ± 9.2 and 5.0 ± 2.2, respectively. The correlation between the administered activity and tumor absorbed dose was weak (r = 0.5, P > 0.05), however, healthy liver absorbed dose increased with administered activity (r = 0.8, P = 0.0). CONCLUSIONS: This study demonstrated correlation in mean TLR between 99m Tc-MAA and 90 Y microsphere SPECT/CT.

Raman spectra of thiolated arsenicals with biological importance.

Surface enhanced Raman scattering (SERS) has great potential as an alternative tool for arsenic speciation in biological matrices. SERS measurements have advantages over other techniques due to its ability to maintain the integrity of arsenic species and its minimal requirements for sample preparation. Up to now, very few Raman spectra of arsenic compounds have been reported. This is particularly true for thiolated arsenicals, which have recently been found to be widely present in humans. The lack of data for Raman spectra in arsenic speciation hampers the development of new tools using SERS. Herein, we report the results of a study combining the analysis of experimental Raman spectra with that obtained from density functional calculations for some important arsenic metabolites. The results were obtained with a hybrid functional B3LYP approach using different basis sets to calculate Raman spectra of the selected arsenicals. By comparing experimental and calculated spectra of dimethylarsinic acid (DMAV), the basis set 6-311++G** was found to provide computational efficiency and precision in vibrational frequency prediction. The Raman frequencies for the rest of organoarsenicals were studied using this basis set, including monomethylarsonous acid (MMAIII), dimethylarsinous acid (DMAIII), dimethylmonothioarinic acid (DMMTAV), dimethyldithioarsinic acid (DMDTAV), S-(Dimethylarsenic) cysteine (DMAIII(Cys)) and dimethylarsinous glutathione (DMAIIIGS). The results were compared with fingerprint Raman frequencies from As─O, As─C, and As─S obtained under different chemical environments. These fingerprint vibrational frequencies should prove useful in future measurements of different species of arsenic using SERS.

Polyethylene glycol modified ORMOSIL theranostic nanoparticles for triggered doxorubicin release and deep drug delivery into ovarian cancer spheroids.

A novel pegylated multifunctional probe of Ormosil nanoparticles (PEGCDSIR820) loaded with Near Infrared dye (NIR; IR820) and a chemotherapeutic drug, Doxorubicin (DOX) was developed for cancer theranostic applications. PEGCDSIR820 nanoparticles had an average diameter of 58.2±3.1nm, zeta potential of -6.9±0.1mV in cell culture media and stability against aggregation in physiological buffers. The encapsulation efficiency of DOX was 65.0±3.0%, and that of IR820 was 76.0±2.1%. PEGCDSIR820 showed no cytotoxicity in ovarian cancer cells (Skov-3). The cytotoxicity markedly increased when Skov-3 cells incubated with PEGCDSIR820 particles were exposed to 808nm laser due to the combination of adjuvant hyperthermia (43°C) and enhanced DOX release. Exposure to laser enhanced the release of DOX, 45% of DOX release was observed in 3h compared to 23% without laser exposure. Confocal imaging in Skov-3 cells showed that the combination of hyperthermia due to NIR exposure and release of DOX caused cell necrosis. Furthermore, in spheroids exposed to NIR laser penetration of DOX was deeper compared to the absence of laser exposure. Skov-3 spheroids incubated with pegylated nanoparticles for 24h and exposed to laser showed 94% reduction in cell viability. Encapsulation of IR820 in PEGCDSIR820 increased the in-vivo elimination half-life to 41.0±7.2h from 30.5±0.5h of free IR820.

Multifunctional organically modified silica nanoparticles for chemotherapy, adjuvant hyperthermia and near infrared imaging.

We report a novel system of organically modified silica nanoparticles (Ormosil) capable of near infrared fluorescence and chemotherapy with adjuvant hyperthermia for image guided cancer therapy. Ormosil nanoparticles were loaded with a chemotherapeutic, Doxorubicin (DOX) and cyanine dye, IR820. Ormosil particles had a mean diameter of 51.2±2.4 nanometers and surface charge of -40.5±0.8mV. DOX was loaded onto Ormosil particles via physical adsorption (FDSIR820) or covalent linkage (CDSIR820) to the silanol groups on the Ormosil surface. Both formulations retained DOX and IR820 over a period of 2 days in aqueous buffer, though CDSIR820 retained more DOX (93.2%) compared to FDSIR820 (77.0%) nanoparticles. Exposure to near infrared laser triggered DOX release from CDSIR820. Uptake of nanoparticles was determined by deconvolution microscopy in ovarian carcinoma cells (Skov-3). CDSIR820 localized in the cell lysosomes whereas cells incubated with FDSIR820 showed DOX fluorescence from the nucleus indicating leakage of DOX from the nanoparticle matrix. FDSIR820 nanoparticles showed severe toxicity in Skov-3 cells whereas CDSIR820 particles had the same cytotoxicity profile as bare (No DOX and IR820) Ormosil particles. Furthermore, exposure of CDSIR820 nanoparticles to Near Infrared laser at 808 nanometers resulted in generation of heat (to 43°C from 37°C) and resulted in enhanced cell killing compared to Free DOX treatment. Bio-distribution studies showed that CDSIR820 nanoparticles were primarily present in the organs of Reticuloendothelial (RES) system.

18F-FLT Positron Emission Tomography/Computed Tomography Imaging in Pancreatic Cancer: Determination of Tumor Proliferative Activity and Comparison with Glycolytic Activity as Measured by 18F-FDG Positron Emission Tomography/Computed Tomography Imaging.

OBJECTIVE: This phase-I imaging study examined the imaging characteristic of 3'-deoxy-3'-(18F)-fluorothymidine (18F-FLT) positron emission tomography (PET) in patients with pancreatic cancer and comparisons were made with (18F)-fluorodeoxyglucose (18F-FDG). The ultimate aim was to develop a molecular imaging tool that could better define the biologic characteristics of pancreas cancer, and to identify the patients who could potentially benefit from surgical resection who were deemed inoperable by conventional means of staging. METHODS: Six patients with newly diagnosed pancreatic cancer underwent a combined FLT and FDG computed tomography (CT) PET/CT imaging protocol. The FLT PET/CT scan was performed within 1 week of FDG PET/CT imaging. Tumor uptake of a tracer was determined and compared using various techniques; statistical thresholding (z score=2.5), and fixed standardized uptake value (SUV) thresholds of 1.4 and 2.5, and applying a threshold of 40% of maximum SUV (SUVmax) and mean SUV (SUVmean). The correlation of functional tumor volumes (FTV) between 18F-FDG and 18F-FLT was assessed using linear regression analysis. RESULTS: It was found that there is a correlation in FTV due to metabolic and proliferation activity when using a threshold of SUV 2.5 for FDG and 1.4 for FLT (r=0.698, p=ns), but a better correlation was obtained when using SUV of 2.5 for both tracers (r=0.698, p=ns). The z score thresholding (z=2.5) method showed lower correlation between the FTVs (r=0.698, p=ns) of FDG and FLT PET. CONCLUSION: Different tumor segmentation techniques yielded varying degrees of correlation in FTV between FLT and FDG-PET images. FLT imaging may have a different meaning in determining tumor biology and prognosis.

Multifunctional Surface-Enhanced Raman Spectroscopy-Detectable Silver Nanoparticles Combined Photodynamic Therapy and pH-Triggered Chemotherapy.

This research paper reports the development of a multifunctional anti-cancer prodrug system based on silver nanoparticles. This prodrug system is composed of 70-nm sized nanoparticles and features photodynamic therapeutic properties and active, pH-triggered drug release. The silver nanoparticles are decorated with a folic acid (FA) targeting ligand via an amide bond, and also conjugated to the chemotherapeutic drug doxorubicin (DOX) via an acid-cleavable hydrazone bond. Both FA and DOX are attached to the silver nanoparticles through a polyethylene glycol (PEG) spacer. This prodrug system can preferentially enter cells that over-express folic acid receptors, with subsequent intracellular drug release triggered by reduced intracellular pH. Moreover, the silver nanoparticle carrier system exhibits photodynamic therapeutic (PDT) activity, so that the cell viability of cancer cells that overexpress folate receptors can be further reduced upon light irradiation. The dual effects of pH-triggered drug release and PDT increase the therapeutic efficacy of this system. The multifunctional nanoparticles can be probed intracellularly through Surface-Enhanced Raman Spectroscopy (SERS) and fluorescence spectroscopy. The current report explores the applicability of this multifunctional silver nanoparticle-based system for cancer theranostics.

Efficient intracellular delivery and improved biocompatibility of colloidal silver nanoparticles towards intracellular SERS immuno-sensing.

High throughput intracellular delivery strategies, electroporation, passive and TATHA2 facilitated diffusion of colloidal silver nanoparticles (AgNPs) are investigated for cellular toxicity and uptake using state-of-art analytical techniques. The TATHA2 facilitated approach efficiently delivered high payload with no toxicity, pre-requisites for intracellular applications of plasmonic metal nanoparticles (PMNPs) in sensing and therapeutics.

Covalent IR820-PEG-diamine nanoconjugates for theranostic applications in cancer.

Near-infrared dyes can be used as theranostic agents in cancer management, based on their optical imaging and localized hyperthermia capabilities. However, their clinical translatability is limited by issues such as photobleaching, short circulation times, and nonspecific biodistribution. Nanoconjugate formulations of cyanine dyes, such as IR820, may be able to overcome some of these limitations. We covalently conjugated IR820 with 6 kDa polyethylene glycol (PEG)-diamine to create a nanoconjugate (IRPDcov) with potential for in vivo applications. The conjugation process resulted in nearly spherical, uniformly distributed nanoparticles of approximately 150 nm diameter and zeta potential -0.4±0.3 mV. The IRPDcov formulation retained the ability to fluoresce and to cause hyperthermia-mediated cell-growth inhibition, with enhanced internalization and significantly enhanced cytotoxic hyperthermia effects in cancer cells compared with free dye. Additionally, IRPDcov demonstrated a significantly longer (P<0.05) plasma half-life, elimination half-life, and area under the curve (AUC) value compared with IR820, indicating larger overall exposure to the theranostic agent in mice. The IRPDcov conjugate had different organ localization than did free IR820, with potential reduced accumulation in the kidneys and significantly lower (P<0.05) accumulation in the lungs. Some potential advantages of IR820-PEG-diamine nanoconjugates may include passive targeting of tumor tissue through the enhanced permeability and retention effect, prolonged circulation times resulting in increased windows for combined diagnosis and therapy, and further opportunities for functionalization, targeting, and customization. The conjugation of PEG-diamine with a near-infrared dye provides a multifunctional delivery vector whose localization can be monitored with noninvasive techniques and that may also serve for guided hyperthermia cancer treatments.

Chemotherapy-induced changes in cardiac capillary permeability measured by fluorescent multiple indicator dilution.

Anthracyclines cause severe irreversible cardiac toxicity. The study of changes in cardiac permeability with chemotherapy could enhance the understanding of mechanisms behind cardiac damage, and provide useful information to evaluate anthracycline cardiotoxicity. Thirty-six rats (12 Sprague-Dawley, 12 Wistar, 12 Fischer-344) were randomly assigned to control (n = 21) or doxorubicin (n = 15), and injected i.p. with a cumulative dose of 18 mg/kg doxorubicin in saline (vehicle) or vehicle alone over 12 days. Echocardiography was performed at baseline and on day 11. An isolated heart experiment was done on day 12 to obtain perfused heart pressure values, and to measure cardiac capillary permeability using a Texas Red/sodium fluorescein multiple indicator dilution method. Control animals had significantly lower average permeability-surface-area-products (0.035 ± 0.013 cm(3)/s) than doxorubicin animals (0.066 ± 0.023 cm(3)/s), PSP ± SD, p < 0.001. These permeability changes correlated with significant functional changes. There was a significant decline in cardiac function with a deleterious effect of chemotherapy on fractional shortening (p < 0.001), left ventricular developed pressure (p < 0.001), contractility (p < 0.001), and relaxation (p = 0.02). Based on our results, cardiac capillary permeability changes can be detected after in vivo chemotherapy treatment using our fluorescent multiple indicator dilution technique, and may provide valuable information in evaluating cardiotoxicity of novel drugs.

A low-interaction automatic 3D liver segmentation method using computed tomography for selective internal radiation therapy.

This study introduces a novel liver segmentation approach for estimating anatomic liver volumes towards selective internal radiation treatment (SIRT). The algorithm requires minimal human interaction since the initialization process to segment the entire liver in 3D relied on a single computed tomography (CT) slice. The algorithm integrates a localized contouring algorithm with a modified k-means method. The modified k-means segments each slice into five distinct regions belonging to different structures. The liver region is further segmented using localized contouring. The novelty of the algorithm is in the design of the initialization masks for region contouring to minimize human intervention. Intensity based region growing together with novel volume of interest (VOI) based corrections is used to accomplish the single slice initialization. The performance of the algorithm is evaluated using 34 liver CT scans. Statistical experiments were performed to determine consistency of segmentation and to assess user dependency on the initialization process. Volume estimations are compared to the manual gold standard. Results show an average accuracy of 97.22% for volumetric calculation with an average Dice coefficient of 0.92. Statistical tests show that the algorithm is highly consistent (P = 0.55) and independent of user initialization (P = 0.20 and Fleiss' Kappa = 0.77 ± 0.06).

Thermal and pH Sensitive Multifunctional Polymer Nanoparticles for Cancer Imaging and Therapy.

In this study, we prepared novel poly(Glycerol malate co-dodecanedioate) (PGMD) NPs containing an imaging/hyperthermia agent (IR820) and a chemotherapeutic agent (doxorubicin, DOX). The PGMD polymer was prepared by thermal condensation. IR820 and DOX loaded PGMD NPs were prepared using the single oil emulsion technique. The size of the NPs measured was around 150 nm. Drug loading efficiency of DOX and IR820 was around 4% and 8%, respectively. An acidic environment (pH=5.0) induced higher DOX release as compared to pH=7.4. DOX release was also enhanced by exposure to laser, which increased the temperature to 42°C. Cytotoxicity of the drug loaded NPs was comparable in MES-SA but was higher in Dx5 cells compared to free drug (p<0.05). The combination of hyperthermia and chemotherapy improved cytotoxicity in both cell lines. The NP formulation significantly improved the plasma half-life of IR820 in mice after tail vein injection.

Targeted nanoparticles for simultaneous delivery of chemotherapeutic and hyperthermia agents--an in vitro study.

The purpose of this study was to prepare targeted Poly lactide-co-glycolide (PLGA) nanoparticles with simultaneous entrapment of indocyanine green (ICG) and doxorubicin (DOX) by surface decorating them with tumor specific monoclonal antibodies in order to achieve simultaneous therapy and imaging. ICG was chosen as an imaging and hyperthermia agent and DOX was used as a chemotherapeutic agent. ICG and DOX were incorporated into PLGA nanoparticles using the oil-in-water emulsion solvent evaporation technique. These nanoparticles were further surface decorated with antibodies against Human Epithelial Receptor-2 (HER-2) using carbodiimide chemistry. The uptake of antibody conjugated ICG-DOX-PLGA nanoparticles (AIDNP) was enhanced in SKOV-3 (HER-2 overexpressing cell lines) compared to their non-conjugated counterparts (ICG-DOX-PLGA nanoparticles (IDNP)). The uptake of antibody conjugated ICG-DOX-PLGA nanoparticles, however, was similar in MES-SA and MES-SA/Dx5 cancer cells (HER-2 negative cell lines), which were used as negative controls. The cytotoxicity results after laser treatment (808 nm, 6.7 W/cm(2)) showed an enhanced toxicity in treatment of SKOV-3. The negative controls exhibited comparable cytotoxicity with or without exposure to the laser. Thus, this study showed that these antibody conjugated ICG-DOX-PLGA nanoparticles have potential for combinatorial chemotherapy and hyperthermia.

Near-infrared dye loaded polymeric nanoparticles for cancer imaging and therapy and cellular response after laser-induced heating.

BACKGROUND: In the past decade, researchers have focused on developing new biomaterials for cancer therapy that combine imaging and therapeutic agents. In our study, we use a new biocompatible and biodegradable polymer, termed poly(glycerol malate co-dodecanedioate) (PGMD), for the synthesis of nanoparticles (NPs) and loading of near-infrared (NIR) dyes. IR820 was chosen for the purpose of imaging and hyperthermia (HT). HT is currently used in clinical trials for cancer therapy in combination with radiotherapy and chemotherapy. One of the potential problems of HT is that it can up-regulate hypoxia-inducible factor-1 (HIF-1) expression and enhance vascular endothelial growth factor (VEGF) secretion. RESULTS: We explored cellular response after rapid, short-term and low thermal dose laser-IR820-PGMD NPs (laser/NPs) induced-heating, and compared it to slow, long-term and high thermal dose heating by a cell incubator. The expression levels of the reactive oxygen species (ROS), HIF-1 and VEGF following the two different modes of heating. The cytotoxicity of NPs after laser/NP HT resulted in higher cell killing compared to incubator HT. The ROS level was highly elevated under incubator HT, but remained at the baseline level under the laser/NP HT. Our results show that elevated ROS expression inside the cells could result in the promotion of HIF-1 expression after incubator induced-HT. The VEGF secretion was also significantly enhanced compared to laser/NP HT, possibly due to the promotion of HIF-1. In vitro cell imaging and in vivo healthy mice imaging showed that IR820-PGMD NPs can be used for optical imaging. CONCLUSION: IR820-PGMD NPs were developed and used for both imaging and therapy purposes. Rapid and short-term laser/NP HT, with a low thermal dose, does not up-regulate HIF-1 and VEGF expression, whereas slow and long term incubator HT, with a high thermal dose, enhances the expression of both transcription factors.