The brain functional connectivity alterations in traumatic patients with olfactory disorder after low-level laser therapy demonstrated by fMRI.

BACKGROUND: Low-level laser therapy (LLLT) has been clinically accepted to accelerate the nerve regeneration process after a nerve injury or transection. We aimed to investigate the neuronal basis and the influence of LLLT on brain functional networks in traumatic patients with olfactory dysfunction. METHODS: Twenty-four Patients with traumatic anosmia/hyposmia were exposed to pleasant olfactory stimuli during a block-designed fMRI session. After a 10-week period, patients as control group and patients who had completed the sessions of LLLT were invited for follow-up testing using the same fMRI protocol. Two-sample t-tests were conducted to explore group differences in activation responding to odorants (p-FDR-corrected <0.05). Differences of functional connectivity were compared between the two groups and the topological features of the olfactory network were calculated. Correlation analysis was performed between graph parameters and TDI score. RESULTS: Compared to controls, laser-treated patients showed increased activation in the cingulate, rectus gyrus, and some parts of the frontal gyrus. Shorter pathlength (p = 0.047) and increased local efficiency (p = 0.043) within the olfactory network, as well as decreased inter-network connectivity within the whole brain were observed in patients after laser surgery. Moreover, higher clustering and local efficiency were related to higher TDI score, as manifested in increased sensitivity to identify odors. CONCLUSIONS: The results support that low-level laser induces neural reorganization process and make new connections in the olfactory structures. Furthermore, the connectivity parameters may serve as potential biomarkers for traumatic anosmia or hyposmia by revealing the underlying neural mechanisms of LLLT.

Simulation and In Vitro Experimental Studies on Targeted Photothermal Therapy of Cancer using Folate-PEG-Gold Nanorods.

BACKGROUND: Selective targeting of malignant cells is the ultimate goal of anticancer studies around the world. There are some modalities for cancer therapy devastating tumor size and growth rate, meanwhile attacking normal cells. Utilizing appropriate ligands, like folate, allow the delivery of therapeutic molecules to cancer cells selectively. There are a variety of photosensitizers, like gold nanorods (GNRs), capable of absorbing the energy of light and converting it to heat, evidently build a photothermal procedure for cancer therapy. OBJECTIVE: To develop a one-step approach for calculating the temperature distribution by solving the heat transfer equation with multiple heat sources originating from NIR laser-exposed GNRs. MATERIAL AND METHODS: In this experimental study, we simulated NIR laser heating process in a single cancer cell, with and without incubation with folate conjugated PEG-GNRs. This simulation was based on a real TEM image from an experiment with the same setup. An in vitro experiment based on aforesaid scenario was performed to validate the simulated model in practice. RESULTS: According to the simplifications due to computational resource limits, the resulting outcome of simulation showed significant compatibility to the supporting experiment. Both simulation and experimental studies showed a similar trend for heating and cooling of the cells incubated with GNRs and irradiated by NIR laser (5 min, 1.8 W/cm2). It was observed that temperature of the cells in microplate reached 53.6 °C when irradiated by laser. CONCLUSION: This new method can be of great application in developing a planning technique for treating tumors utilizing GNP-mediated thermal therapy.

A multimodal MR-compatible olfactometer with real-time controlling capability.

Design of an MR-compatible and computer-controlled odour stimuli system is essential in the studies of human olfactory function. Olfactometers are used to deliver odours to the subjects in an objective manner. We present a portable, computer-controlled eight channels olfactometer able to stimulate olfaction by employing liquid odorant stimuli. We used a high-pressure pump to generate medical grade airflow. After passing through solenoid valve-controlled odour reservoirs, odorant stimulus is conveyed to the nasal mask. The odour delivery delay of the device was measured using photo-ionisation detectors. To assess the application of the designed olfactometer, an fMRI experiment was done with 9 healthy subjects. Two odour stimuli (Vanillin and Rose) were presented to each subject in an alternating block design task of odour and non-odour conditions. The response time of each subject was gathered using the response box. Group analysis revealed a significant BOLD signal change in some regions of olfactory and trigeminal networks including the orbitofrontal cortex, insula, inferior frontal gyrus, hippocampus, cingulate gyrus and piriform cortex. The odour delivery delay measured by photo-ionisation detector was 190 ms, and the subjects' response showed 205 ms for the Vanillin and 243 ms for the Rose odour stimuli. Our portable MR-compatible olfactometer as a stimulation device is capable of creating adequate stimulation suitable for olfactory fMRI experiments.

Real-time mapping of heat generation and distribution in a laser irradiated agar phantom loaded with gold nanoparticles using MR temperature imaging.

Gold nanoparticles (AuNPs) have shown potential strength in photothermal therapy of cancer. Several techniques have been developed to investigate local heat generation by AuNPs. However, a sensitive thermal imaging technology with high temporal resolution, minimum invasiveness and high spatial resolution is still lacking. In this research study, by using magnetic resonance thermal imaging (MRTI), we reported a technique for monitoring of heat generation and distribution in an AuNPs loaded agar phantom irradiated by laser. Three different agar phantoms with various AuNPs concentrations (0, 8 and 16 µg/ml) were produced and studied. The phantoms were exposed to an external laser [532 nm; 4 min] under MRTI. For real-time temperature monitoring, we employed the theory of proton resonance frequency (PRF) shift. Infrared (IR) camera was employed to measure the actual temperature of each point on the surface of irradiated agar gel. Finally, the correlation between the temperatures obtained by IR camera and MRTI was evaluated. We observed that temperature of the gels loaded by AuNPs at concentration of 0, 8 and 16 µg/ml reached 27.2, 37.8, 45 °C with a total area of heat distribution of 94.98, 452.16, and 907.34 mm2 (from the point of irradiation). During the process of laser irradiation, we observed: (i) a significant rise in temperature, (ii) a dependency between the rate of temperature rise and concentration of AuNPs, and (iii) a direct correlation between temperature change and MR image phase. In addition, statistical analysis showed that the variation of temperatures measured by IR camera and temperatures computed by MRTI had acceptable correlation (R > 0.9). In conclusion, MRTI has a good sensitivity and precision that can be employed for nano-photothermal therapy planning and may be considered for real-time mapping of heat generation and distribution in a laser irradiated tissue loaded by AuNPs.

Multimodal cancer cell therapy using Au@Fe2O3 core-shell nanoparticles in combination with photo-thermo-radiotherapy.

In this study, gold coated iron oxide nanoparticle (Au@Fe2O3 NP) was synthesized in a core-shell structure. Photothermal and radiosensitization effects of Au@Fe2O3 NPs were investigated on KB human mouth epidermal carcinoma cell line. Cell death and apoptosis were measured to study the effects of nanoparticles in combination with both radiotherapy (RT) and photothermal therapy (PTT). The KB cells were treated with Au@Fe2O3 NPs (20 µg/ml; 4 h) and then received different treatment regimens of PTT and/or RT using laser (808 nm, 6 W/cm2, 10 min) and/or 6 MV X-ray (single dose of 2 Gy). Following the various treatments, MTT assay was performed to evaluate the cell survival rate. Also, the mode of cell death was determined by flow cytometry using an annexinV-fluorescein isothiocyanate/propidium iodide apoptosis detection kit. No significant cell death was observed due to laser irradiation. The viability of the cells firstly incubated with NPs and then exposed to the laser was significantly decreased. Additionally, our results demonstrated that Au@Fe2O3 NP is a good radiosensitizer at megavoltage energies of X-ray. When nanoparticles loaded KB cells were received both laser and X-ray, the cell viability substantially decreased. Following such a combinatorial treatment, flow cytometry determined that the majority of cell death relates to apoptosis. In conclusion, Au@Fe2O3 NP has a great potential to be applied as a photo-thermo-radiotherapy sensitizer for treatment of head and neck tumors.

Selective apoptosis induction in cancer cells using folate-conjugated gold nanoparticles and controlling the laser irradiation conditions.

In this study, we explained in detail a targeted nano-photo-thermal therapy (NPTT) method to induce selective apoptosis in cancer cells. Folate-conjugated gold nanoparticles (F-AuNPs) were synthesized by tailoring the surface of AuNPs with folic acid to enhance the specificity of NPTT. KB cancer cells, as a folate receptor over-expressing cell line, and L929 normal cells with low level of folate receptors were incubated with the synthesized F-AuNPs and then irradiated with various laser intensities and exposure durations. Following various regimes of NPTT, we assessed the level of cell viability and the ratio of apoptosis/necrosis. No significant cytotoxicity was observed for both cell lines at concentrations up to 40 µM of F-AuNPs. Moreover, no significant cell lethality occurred for various laser irradiation conditions. The viability of KB and L929 cells incubated with F-AuNPs (40 µM; 6 h) and then irradiated by laser (1 W/cm2; 2 min) was 57 and 83%, respectively. It was also demonstrated that the majority of cancer cell death is related to apoptosis (41% apoptosis of 43% overall cell death). In this process of F-AuNPs based NPTT, it may be concluded that the main factor determining whether a cell dies due to apoptosis or necrosis depends on laser irradiation conditions. In this study, we explained in detail a targeted nano-photo-thermal therapy (NPTT) method to induce selective apoptosis in cancer cells.

Folic acid conjugated PEG coated gold-iron oxide core-shell nanocomplex as a potential agent for targeted photothermal therapy of cancer.

This study reports the synthesis and characterization of poly(ethylene glycol) coated gold@iron oxide core-shell nanoparticles conjugated with folic acid (FA-PEG-Au@IONP). Also, targeted therapeutic properties of such a nanocomplex were studied on human nasopharyngeal carcinoma cell line KB and human breast adenocarcinoma cell line MCF-7 in vitro. The synthesized nanocomplex was characterized by transmission electron microscopy (TEM), dynamic light scattering (DLS), UV-Vis spectroscopy, vibrating sample magnetometry (VSM), and Fourier transform infrared (FTIR) spectroscopy. The photothermal effects of nanocomplex on both KB and MCF-7 cell lines were studied. Cell death and apoptosis were evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and flow cytometry using an annexin V-fluorescein isothiocyanate/propidiumiodide apoptosis detection kit. It was found that nanocomplex is spherical in shape and its size is approximately 60 nm. UV-vis spectrum showed that nanocomplex has appropriate absorption near infrared region. FTIR spectra obtained from nanocomplex before and after conjugation with FA confirmed the formation of folate conjugated nanocomplex. Significant cell lethality was observed for KB (∼62%) and MCF-7 (∼33%) cells following photothermal therapy. Also, it was found that majority of the cell deaths were related to apoptosis process. It can be concluded that, the synthesized nanocomplex is an effective and promising multifunctional nanoplatform for targeted photothermal therapy of cancer.

Photothermal therapy using folate conjugated gold nanoparticles enhances the effects of 6MV X-ray on mouth epidermal carcinoma cells.

The aim of this study was to develop an optimized method for preparation of folate conjugated gold nanoparticles (F-AuNPs) and to investigate its cytotoxic effects and cell apoptosis in combination with photothermal therapy (PTT) and radiotherapy (RT) for the treatment of mouth epidermal carcinoma cells KB. For this purpose, cells were treated with synthesized F-AuNPs at different concentrations for 6h and then irradiated them with laser beam (532nm, 0.5W/cm2, 15min). After photothermal therapy, the cells were exposed to 6MV X-ray with a single dose of 2Gy. MTT assay were performed to evaluate the cell survival rate and apoptosis was determined by flow cytometry using an annexin V-fluorescein isothiocyanate/propidium iodide apoptosis detection kit. No significant cell damage or cell apoptosis from the individual treatment of laser light or F-AuNPs was observed, while viability of cells incubated with F-AuNPs and then exposed to the laser was significantly decreased. Additionally, our results demonstrated that F-AuNPs is good radiosensitizers even at a low concentration such as 20µM when megavoltage X-ray is used. Also, when KB cells were treated with F-AuNPs under both laser and X-ray irradiation, the cell viability substantially decreased more than F-AuNPs-enhanced PTT alone or F-AuNPs-enhanced RT alone. Flow cytometry assay clearly indicated that F-AuNPs-mediated photo-thermo-radio therapy significantly induced apoptosis. These results confirm that F-AuNPs is a promising and research-worthy nanoconjugate in the field of targeted photo-thermo-radiotherapy of cancer.

A scientific paradigm for targeted nanophotothermolysis; the potential for nanosurgery of cancer.

The application of gold nanoparticles (AuNPs) in nanophotothermolysis as a great photosensitizer is expanding, and this subject is a challenging area for cancer therapy. Recent technological advances in nanoscale manufacturing and synthesis promise the development of highly beneficial and innovative methods for the targeting of cancer. However, there is an obstacle to conducting effective laser-based nanosurgery because AuNPs are activated by visible or near infrared wavelengths, and the penetration of a laser beam inside the body is limited by some absorbents, such as melanin, water, and blood molecules. Considering everything stated above, we have suggested the application of a folate-conjugated AuNP as an effective agent for targeted nanophotothermolysis and the application of an optical fiber to transport the laser light from the source to the target tissue inside the body. Thus, a new method of nanosurgery in which a surgeon is able to perform surgery at the cellular or even at the subcellular level may be possible.

Evaluation of diagnostic values of photodynamic diagnosis in identifying the dermal and mucosal squamous cell carcinoma.

OBJECTIVES: We conducted a study to determine and compare the efficacy of pathology and photodynamic studies in establishing diagnosis of malignant dermal and mucosal lesions. METHODS AND PATIENTS: This descriptive cross-sectional study was performed on 40 patients suspected of SCC (squamous cell carcinoma). First, in PDD (photodynamic diagnosis) photosensitizing agent was applied to the lesion, and after 4-5h the fluorescence spectrum was detected by laser radiation. Based on fluorescence intensity, normal area was differentiated from malignant area. Also, biopsy samples from these suspected areas were sent to pathology simultaneously. Data were analyzed with SPSS v.16. The distribution of nominal variables was compared using the Chi-square test. Diagnostic index for photodynamic diagnosis were calculated. A two-sided p-value<0.05 was considered to be statistically significant. RESULTS: In 27 cases (90%), results of pathology and photodynamic studies similarly showed malignancy. In 8 cases (80%), results of pathology and photodynamic studies similarly showed non-malignant lesion. But in five cases (12.5%) the results of pathology and photodynamic studies were not the same. This difference was not statistically significant showed by the Chi-square test analysis (p-value>0.05). A sensitivity of 90%, specificity of 80%, accuracy of 87.5%, positive predictive value (PPV) of 93%, negative predictive value (NPV) of 72%, positive likelihood ratio (PLR) of 4.5, negative likelihood ratio(NLR) of 0.125 were found in diagnosing SCC for photodynamic studies. CONCLUSION: Photodynamic diagnosis is a useful non-invasive initial step in the diagnostic work-up of patients with suspected malignant lesions (SCC). In this work we have studied 40 SCC suspicious patients using PDD method and successfully carried out 27 cases as malignant all of which were matching with pathologic results. This outcome can prove both accuracy and reliability of PDD method for detecting SCC lesions on head and neck regions. Also PDD can fully demarcate the lesion peripheries less invasively as well as preserving much more time and effort. Although PDD method is a bit more expensive that biopsy and pathology but great advantages can easily cover this issue. We recommend PDD as a useful easy technique to visualize and detect the extension of the tumor preoperatively.

The efficacy of photodynamic therapy in treatment of recurrent squamous cell and basal cell carcinoma.

OBJECTIVES: A number of investigations have already been carried out to assess the effect of photodynamic therapy (PDT) on primary basal cell carcinoma (BCC) and squamous cell carcinoma (SCC) lesions, but lack of investigations on recurrent lesions or lesions with treatment failure, prompted the authors to carry out this study. The aim of the present study was to evaluate the efficacy of photodynamic therapy on recurrent BCC and SCC lesions on head and neck skin. PATIENTS AND METHODS: A total of 30 patients, including 16 men and 14 women, were selected from patients with recurrent SCC and BCC who referred to Iran university ENT research center Rasool-e-Akram Hospital, Tehran-Iran, met the criteria and entered the study. This is a longitudinal study of 30 patients with 43 histologically verified head and neck skin tumors, candidate for photodynamic therapy. RESULTS: To cite the results obtained in this study, it is worth mention that five cases expressed disagreement with this treatment modality after the first session of illumination; the treatment was stopped because of pain or burning. In a three-month evaluation, complete treatment response rates were obtained in 72% of patients (18 cases); in SCC cases it was 71.4% (10 cases) and in BCC it was 72.7% (eight cases). The final result of complete response rate in three years of follow up, demonstrated that 16 (64%) patients out of 25 were disease-free from recurrent BCC and SCC (Table 1). In BCC cases the final three-year response rate was seven (63.6%) and in SCC cases it was nine (64.2%). Hence, there was no statistical difference between SCC and BCC cases to treatment (P = 0.34). DISCUSSION: The obtained data from the current study is supportive of the recommended treatment method of PDT as an effective, tolerable and less invasive treatment in patients with recurrent BCC and SCC carcinomas, particularly when cosmetic effects are an important consideration. However, more research is needed to establish this.