This PDF file contains the front matter associated with SPIE Proceedings Volume 10417, including the Title Page, Copyright information, Table of Contents, and Conference Committee listing

Photobiomodulation (PBM) triggers proliferation of many type of cell, including fibroblasts. Although PBM has positive effects on modulation of ample biological processes, significant contradictions in underlying process has been waiting for gathering and clarifying. This preliminary study evaluated the efficacy of correct combination between different energy densities and intensities of 635 nm laser light. This study aimed to investigate and identify the compatible match of energy and power density to proliferate L929 cell line. Cells were plated at a cell density of 20,000cells per well on 96-well polystyrene plates. The plates were incubated for 24 h and then, the wells were irradiated using power densities of 30 mW/cm², 50 mW/cm², 125 mW/cm², and 200 mW/cm². Energy densities used in this study were 1 J/cm², 3 J/cm², and 5 J/cm². 1 J/cm² laser energy density stimulated significantly the proliferation of L929 cells at 30 mW/cm², 50 mW/cm², 125 mW/cm². However, the proliferation at 3 J/cm² was significantly (p ≤ 0.05) higher than the proliferation at 1 J/cm² when 200 mW/cm² of laser power density was used. In conclusion, the results show that the stimulatory effect of PBM depends on both energy density and power density. Thus, the combination of laser energy density and intensity may change the treatment response.

In this present study we investigate the Radachlorin photosensitizer accumulation in K562 cells and Hela cells and determined the cell viability after PDT. Using the macroscopic singlet oxygen modeling and cellular photosensitizer concentration the singlet oxygen threshold doses for K562 cells and Hela cells were calculated.

Photodynamic Therapy is a selective optical tumor destruction technique with practically no secondary effects. Monitoring by fluorescence photosensitizer emission is essential for an adequate treatment dosimetry, which avoids recurrence.

Prostate cancer is the second most frequently diagnosed cancer among men worldwide and a novel treatment for the disease is required. Replication-deficient virus particles, hemagglutinating virus of Japan envelope (HVJ-E), has cytotoxicity to cancer cells. To enhance the therapeutic effect of HVJ-E by photodynamic therapy (PDT) as a trigger of HVJ-E’s anti-tumor effect, talaporfin sodium (Laserphyrin) used for PDT was encapsulated into HVJ-E to produce a novel photosensitizing drug, named Laserphyrin ®-HVJ-E, and its therapeutic effect for prostate cancer cells (PC-3) was evaluated. As the results, direct cytotoxicities of HVJ-E and Laserphyrin ®-HVJ-E for PC-3 after an administration time of 48 h were almost the same. Cell survival rates of PC-3, which were irradiated 2 h after administration of Laserphyrin ®-HVJ-E, were about 7.8%. Although further study is needed to find an optimal PDT condition, these results suggest that Laserphyrin ®-HVJ-E is useful for treatment of prostate cancer due to the combination of cytotoxicities of HVJ-E and PDT.

A faster healing process was observed in superficial skin wounds after irradiation with a blue LED (EmoLED) photocoagulator. EmoLED is a compact handheld device, used to induce a thermal effect and thus coagulation in superficial abrasions. We present the results of an in vivo study, conducted in different mouse model, to analyze the induced wound healing. Two superficial abrasions were produced on the back of the mice: one area was treated with EmoLED (1.4 W/cm2, 30 s treatment time), while the other one was left naturally recovering. During the treatment, a temperature around 40-45°C was induced on the abrasion surface. Mice back healthy skin was used as a control. We compared the treatment in black mice, healthy albino mice, diabetic albino mice and albino mice with coagulation problem. The animals underwent a follow up study and were sacrificed at 0, 3, 6, 9, 18, 24 hours p.o.. Samples from the two abraded areas were harvested and examined by histopathological and immunofluorescence analysis, SHG imaging and confocal microscopy. The aim of the study was to compare the effects in the different target groups and to investigate the early phase of the wound healing process. Our results show that the effects are comparable in all the treated groups and that the healing process appears to be faster in respect to the naturally recovered wounds. This study confirms the previous results obtained in a study on a rat model an in a study on healthy albino mice: the selective photothermal effect we used for inducing immediate coagulation in superficial wounds seems to be associated to a faster and improved healing process.

Several in vitro and in vivo studies have been performed to investigate the potential of Photothermal Therapy (PTT) as a cancer treatment strategy. However, there are still open questions concerning the optimal parameters for generating cavitation bubbles and acoustic shockwaves for increasing the damage to malignant cells, and the primary mechanism for cell damage in PTT is still a matter of debate. This study investigates PTT based on shockwaves from cavitation induced far from the cells, due to laser absorption by gold nanorods (GNR) colloidal solutions in vitro. The effects of laser energy and distance from the cavitation on cell viability is investigated in PC3 prostate cancer cells, and Escherichia coli (E. coli) cells, respectively.

The conductivity of layers (thickness 0.5 ÷ 50 μm) of composite nanomaterials consisting of bovine serum albumin (BSA) with single-walled carbon nanotubes (SWCNTs) has been studied. The aqueous dispersion of BSA / SWCNT was deposited on different substrates using the silk screening method. Conductivity was increased (30 ÷ 700) % by laser irradiation of the layers when they were in the liquid state. The investigated layers are promising for use in medical practice.

The luminescence spectra of a polymer film with embedded upconversion nanoparticles (UCNPs) were measured through 0.1-0.3 mm adipose tissue layer at heating in a wide temperature range. Heating and application of optical clearing agents improved intensity of UCNP fluorescence significantly.

Samples of liquid dispersions of gold nanorods and nanostars with different size and shape were synthesized and studied based on dynamic light scattering, polarization measurements, electrophoretic light scattering.

Gold nanoparticle mediated laser stimulation of neuronal cells allows for cell activation on a single-cell level. It could therefore be considered an alternative to classical electric neurostimulation. The physiological impact of this new approach has not been intensively studied so far. Here, we investigate the targeted cell’s reaction to a laser stimulus based on its calcium response. A complex cellular reaction involving multiple sources has been revealed.

Optical coherence tomography (OCT) is currently actively introduced into clinical practice. Besides diagnostics, it can be efficiently employed for treatment monitoring allowing for timely correction of the treatment procedure. In monitoring of photodynamic therapy (PDT) traditionally employed fluorescence imaging (FI) can benefit from complementary use of OCT. Additional diagnostic efficiency can be derived from numerical processing of optical diagnostics data providing more information compared to visual evaluation. In this paper we report on application of OCT together with numerical processing for clinical diagnostic in gynecology and otolaryngology, for monitoring of PDT in otolaryngology and on OCT and FI applications in clinical and aesthetic dermatology. Image numerical processing and quantification provides increase in diagnostic accuracy. Keywords: optical coherence tomography, fluorescence imaging, photod

Some of the key optical properties of a new water soluble chlorine (YLG-1) were evaluated. The sensitizer has a strong absorption at 398 nm and 655 nm in DMSO. A strong red fluorescence is detected under the excitation of 398 nm. The fluorescence life time is approximately 5 ns and fluorescence quantum yield 20%. The sensitizer does not accumulate in normal skin after topical use or IV injection. Preliminary in vivo results suggest that this novel chlorine causes little cutaneous phototoxicity. Its potentials in photodynamic therapy (PDT) deserve further study.

The luminescence spectrum of aqueous solution of Radachlorin photosensitizer in the near IR spectral range (950-1350 nm) has been determined at the excitation in both the Soret and Q absorption bands. Major sources of the recorded luminescence were analyzed. Kinetics of photosensitizer and singlet oxygen phosphorescence signals were studied by means of time-resolved spectroscopy. The corresponding characteristic lifetimes were determined.

A new method for non-ablative correction of cornea shape is based on thermo-mechanical effect of laser radiation with ring-shaped laser beam. The results obtained demonstrated that the new method for correction of eye refraction yields a significant alteration in the eye refraction and the ring-shaped laser beam with various ring diameters for correction of the eye refraction allows obtaining controllable alterations of the eye refraction with axial symmetry without any pathological changes in central part of cornea.

We demonstrate a total bacterial inactivation technique by ultrashort pulse direct-laser irradiation that does not require any external agent. Near-infrared fs laser pulses at 89 MHz repetition rate were used to irradiate solutions of distilled water with >10⁷ cell/ml of wild strain of E. coli, showing they can be inactivated with fluences per pulse as low as ~1mJ/cm².

Bacterial infection of cranial implants remains a major cause of implant failure, and often requires surgical intervention to remove and replace the fouled implant. Novel transparent implants may allow for mitigation of infection using optical therapies, without the need for invasive surgeries. In this study, we investigate a combined treatment with ZnO nanoparticles and femtosecond laser pulses to inhibit the growth of Escherichia coli (E. Coli) in vitro. The combined effect has shown a substantial reduction in the number of CFU/mL after incubation compared with no treatment.

Increase the weld strength is main directions of development of laser welding technology. Laser solders are used to increase tensile strength of welds and reduce of tissue temperature necrosis. Soldering components interaction effect the solder tensile strength characteristics of laser welds. Tensile strengths for welds obtained using of solder various concentration BSA and SWCNT was measured. Dimensions laser solder aggregates were measured. The dependence between the dimensions of the aggregates of laser solder and the tensile strength of the weld has been revealed.

We describe a novel method of optical diagnostics of tissues with ballistic photons. They are selected by detecting them in an interferometric setup, further using heterodyning to increase the signal size. Three strategically placed apertures select the beam diameter for spatial resolution in scanning, and the angle within which the partially scattered photons might be collected. We model inclusion inside a bone-like object as a treelayer tissue that includes the skin, the muscle, and the bone. We calculate the size of detected inclusion as a function of limiting signal to noise ratio.

Spectroscopic setup for measuring anisotropy factor g spectrum of biological tissues was constructed. g of chicken liver tissue was lower than chicken breast tissue. High absorption of hemoglobin can have an influence on g spectrum.

A high power pulsed laser with millisecond pulse was used to interact with a bone and muscle of porcine, initiating an acoustic wave. We start to describe principle of laser ablation follows by the acoustic wave generation. Then, we present the characterization of these wave features for laser surgery applications.

Subcritical calvarial defects are important to study bone regeneration during healing. In this study 1mm calvarial defects were created using trephine in the parietal bones of Sprague-Dawley rats (n=7) that served as in vivo defects. Subjects were sacrificed after 7 days and the additional defects were created on the harvested skull with the same method to serve as control defects. Raman spectroscopy is established to investigate mineral/matrix ratio, carbonate/phosphate ratio and crystallinity of three different surfaces; in vivo defects, control defects and normal surface. Results show 21% and 23% decrease in mineral/matrix after 7 days of healing from surface to in vivo and control to in vivo defects, respectively. Carbonate to phosphate ratio was found to be increased by 39% while crystallinity decreased by 26% in both surface to in vivo and control to in vivo defects. This model allows to study the regenerated bone without mechanically perturbing healing surface.

Dental caries in sliced samples are investigated using terahertz pulsed imaging. Frequency domain terahertz response of these structures consistent with X-ray imaging results show the potential of this technique in the detection of early caries.

Repeated pathologies of the tympanic membrane (TM) decrease its tension inducing conductive hearing loss and adhesive processes up to cholesteatoma. Our results regarding the development of a laser based noninvasive procedure to strengthen the structure of the TM are herein presented.

We show that partial solubility of a photosensitizer is not necessarily a bad property when dealing with microbiological control. The presence of curcumin aggregates in solution may present advantages with respect the photoand chemical stability.

The stability of Indocyanine Green was observed in water, DMSO and PBS. We concluded that after a time in PBS at 37°C, ICG forms aggregates with red-shifted absorption.

Sepsis is a potentially fatal condition that occurs when an infectious agent, such as bacteria, gets in a person's bloodstream. The infection affects the immune system, which then triggers a reaction that can cause uncontrolled inflammation in the body¹ . All blood components may present the contamination. Once inoculated bacteria in a blood component, it can proliferate rapidly reaching high levels within few hours and, in a short period, it may lead to several basal changes in the individual and even death² . Studies have shown an increase in the incidence of sepsis over the years, and it is mainly due to the growing resistance of microorganisms to antibiotics since these drugs are still sold and used improperly³ . The photodynamic inactivation (PDI) has been one of the most promising alternatives for microbiological control and other diseases. Its principle of action is based on a photosensitizer (PS) activated by light at the correct wavelength to oxidize organic substrates, resulting in cytotoxic effects^4,5. The technique is being applied to a large variety of microorganisms and decontaminating blood. Some studies have investigated the action of PDI in blood^6–9, and even then, there is a need to understand better what happens when we apply PS and light in blood in an attempt to eliminate the microorganisms. Photogem is a hematoporphyrin derivative that has been used with success in many clinical cases such as skin cancer and inactivation of bacteria^10,11. Previous studies have shown that PDI using Photogem as a photosensitizing molecule is a good alternative for blood decontamination^12,13. In the previous studies were observed hemolysis when red blood cells (RBCs) were submitted to PS concentration and light dose tested. This study has been conducted to further understand through absorption spectroscopy and fluorescence confocal microscope the PS-blood interaction. This is important because the PDI damage needs to be restricted to the bacteria and the blood functions should be preserved.

We developed a longitudinally excited CO₂ laser with a long optical cavity and investigated the drilling characteristics of dental hard tissue. The CO₂ laser was very simple and consisted of a 45-cm-long alumina ceramic pipe with an inner diameter of 13 mm, a pulse power supply, a step-up transformer, a storage capacitance, a spark gap, and a long optical cavity with a cavity length of 175 cm. The CO₂ laser produced a short pulse that had a spike pulse with the width of 337 ns and the energy of 1.9 mJ, a pulse tail with the length of 180 μs and the energy of 37.6 mJ, and a doughnut-like beam. In the investigation, a sample was a natural drying human tooth (enamel and dentine). In a processing system, a ZnSe focusing lens with the focal length of 50 mm was used and the location of the focal plane was that of the sample surface. In 1 pulse irradiation, the drilling characteristics depended on the fluence was investigated. In the enamel and dentin drilling, the drilling depth increased with the fluence. The 1 pulse irradiation with the fluence of 21.5 J/cm² produced the depth of 79.3 μm in the enamel drilling, and the depth of 152.7 μm in the dentin drilling. The short-pulse CO₂ laser produced a deeper drilling depth at a lower fluence than long-pulse CO₂ lasers in dental hard tissue processing.

Amplitude modulation of backscattered light caused by blood volume fluctuations was studied in Laser Doppler Flowmetry. It was shown that the amplitude-modulated signal significantly contributes to the power spectral density of photocurrent and calculated perfusion.

In this paper we present an evaluation of six ciprofloxacin drugs from different laboratories using the Raman spectroscopy technique. We conclude that this technique can be applied as a potential tool in drug quality control.