Increased mobility and stem-cell proliferation rate in Dugesia tigrina induced by 880nm light emitting diode

The therapeutic effects elicited by photobiostimulation in the near infrared range may be associated with increased proliferation rate of particular cell-types. The present study utilized commercial light emitting diodes to investigate the effects of low-level near-infrared radiation on the proliferation rate of stem cells in amputated planarian. Whole and amputated animals were exposed to either ambient diurnal lighting, darkness, white light, red light, or near-infrared (880 nm) light. Irradiation was consistent for the duration of the experiments and was provided using commercial 5mm light emitting diodes (～1.0 mW/m(2) in power density and ～0.01 J/cm(2) in radiant exposure). Compared to other groups amputated planarian exposed to near-infrared displayed increased mobility by the 3rd day of exposure (F((4,26))=4.31, p<0.04, η(2)=41%). Higher densities of stem cells were measured in these worms 84 h post injury (F((4,72))=4.78, p<0.01, η(2)=21%). These findings suggest that non-coherent light sources with power-densities about 1000 times lower than contemporary low-power laser settings remain effective in generating photobiostimulation effects and warrants further investigation on stem-cell proliferation induced by near-infrared light emitting diodes.     

Phototherapeutic Effect of Low‐Level Laser on Thyroid Gland of Gamma‐Irradiated Rats

One inescapable feature of life on the earth is exposure to ionizing radiation. The thyroid gland is one of the most sensitive organs to gamma‐radiation and endocrine disrupters. Low‐level laser therapy (LLLT) has been used to stimulate tissue repair, and reduce inflammation. The aim of this study was to gauge the value of using Helium–Neon laser to repair the damaged tissues of thyroid gland after gamma‐irradiation. Albino rats were used in this study (144 rats), divided into control, gamma, laser, and gamma plus laser‐irradiated groups, each group was divided into six subgroups according to time of treatment (total six sessions). Rats were irradiated once with gamma radiation (6 Gy), and an external dose of laser (Wavelength 632.8 nm, 12 mW, CW, Illuminated area 5.73 cm², 2.1 mW cm^?2, 120 s, 1.4 J, 0.252 J cm^?2) twice weekly localized on thyroid region of the neck, for a total of six sessions. Animals were sacrificed after each session. Analysis included thyroid function, oxidative stress markers, liver function and blood picture. Results revealed improvement in thyroid function, liver function and antioxidant levels, and the blood cells count after LLLT.     

UV-ozone modification of plasma-polymerised acetonitrile films for enhanced cell attachment

Plasma polymerisation is of great interest for modifying the surface properties of biomedical devices in order to control, for example, protein adsorption and cell attachment. In this paper we present results for plasma-polymerised acetonitrile deposited onto silicon or polystyrene substrates. The chemistry of films deposited under a range of experimental conditions was studied by X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FTIR). XPS provided evidence that the elemental composition of the films varied with rf power to flow rate parameter (W/F) with films produced at higher W/F being deficient in nitrogen. FTIR revealed that the plasma deposited film contained a wide range of nitrogen functional groups including amine, imine and nitrile. Oxidation of the films by exposure to radiation from a low pressure mercury vapour lamp in an air ambient increased the surface oxygen levels from 3 to 17 at.% after 300 s exposure. XPS also revealed that the oxidation process proceeded via the formation of carbonyl groups at short exposure times (<60 s) while longer treatment times (>60 s) resulted in an increase in the concentration of carboxyl groups. To assess their potential to support cell growth, polystyrene culture dishes coated with plasma deposited films and UV-ozone oxidised films were seeded with 1BR.3.N human fibroblast cells and incubated for up to 72 h. Un-oxidised plasma-polymerised acetonitrile films were found to give comparable cell attachment densities as tissue culture polystyrene. The greatest cell attachment density was found with plasma polymer films which had been UV-ozone treated for the longest time (300 s). Enhanced attachment to this surface was attributed to the high level of carboxylic groups found on this substrate.     

Effect of laser modified surface microtopochemistry on endothelial cell growth

The introduction of microelectronics technology in the area of biological sciences has brought forth previously unforeseeable applications such as DNA or protein biochips, miniaturized, multiparametric biosensors for high performance multianalyte assays, DNA sequencing, biocomputers, and substrates for controlled cell growth (i.e. tissue engineering). We developed and investigated a new method using “cold” excimer laser beam technology combined with microlithographical techniques to create surfaces with well defined 3D microdomains in order to delineate critical microscopic surface features governing cell–material interactions. Microfabricated surfaces with microgrooves 30–3 μm deep, 10–1 μm wide spaced 30 μm apart were obtained with micron resolution, by “microsculpturing” polymer model surfaces using a computer controlled laser KrF excimer beam coupled with a microlithographic projection technique. The laser beam after exiting a mask was focused onto the polymer target surface via an optical setup allowing for a 10-fold reduction of the mask pattern. Various 3D micropatterned features were obtained at the micron level. Reproducible submicron features could also be obtained using this method. Subsequently, model human umbilical endothelial cells (HUVEC) were cultured on the laser microfabricated surfaces in order to study the effects of specific microscopic surface features on cell deposition and orientation. Cell deposition patterns were found to be microstructure dependant, and showed cell orientation dependency for features in the cell range dimension, a behaviour significantly different from that of a previously studied cell model (osteoprogenitor cell). This model may be a promising in so far as it is very rapid (a time frame less than a second per square centimeter of micropatterned surface) and provides further insights into the effects of surface microtopography on cell response with possible applications in the field of biosensors, biomedical and/or pharmaceutical engineering sciences.     

High Final Energy of Low‐Level Gallium Arsenide Laser Therapy Enhances Skeletal Muscle Recovery without a Positive Effect on Collagen Remodeling

The aim of this study was to evaluate the effects of a Gallium Arsenide (GaAs) laser, using a high final energy of 4.8 J, during muscle regeneration after cryoinjury. Thirty Wistar rats were divided into three groups: Control (C, n = 10); Injured (I, n = 10) and Injured and laser treated (Injured/LLLT, n = 10). The cryoinjury was induced in the central region of the tibialis anterior muscle (TA). The applications of the laser (904 nm, 50 mW average power) were initiated 24 h after injury, at energy density of 69 J cm^?1 for 48 s, for 5 days, to two points of the lesion. Twenty‐four hours after the final application, the TA muscle was removed and frozen in liquid nitrogen to assess the general muscle morphology and the gene expression of TNF‐α, TGF‐β, MyoD, and Myogenin. The Injured/LLLT group presented a higher number of regenerating fibers and fewer degenerating fibers (P < 0.05) without changes in the collagen remodeling. In addition, the Injured/LLLT group presented a significant decrease in the expression of TNF‐α and myogenin compared to the injured group (P < 0.05). The results suggest that the GaAs laser, using a high final energy after cryoinjury, promotes muscle recovery without changing the collagen remodeling in the muscle extracellular matrix.     

Integration exosomes with MOF-modified multifunctional scaffold for accelerating vascularized bone regeneration

Designing a multifunctional scaffold with osteogenic and angiogenic properties holds promise for ideal bone regeneration. Innovative scaffold was here constructed by immobilizing exosomes derived from human bone mesenchymal stem cells (hBMSCs) onto porous polymer meshes which developed by PLGA and Cu-based MOF (PLGA/CuBDC@Exo). The synthesized exosome-laden scaffold capable of providing a dual cooperative controllable release of bioactive copper ions and exosomes that promote osteogenesis and angiogenesis, thereby achieving cell-free bone regeneration. In vitro assay revealed the composite stent not only substantially upregulated the expression of osteogenic-related proteins (ALP, Runx2, Ocn) and VEGF in hBMSCs, but promoted the migration and tube formation of the human umbilical vein endothelial cells (HUVECs). In vivo evaluation further confirmed this scaffold dramatically stimulated bone regeneration and angiogenesis in critical-sized defects in rats. Altogether, this composite scaffold carrying therapeutic exosomes had an osteogenic-angiogenic coupling effect and offered a new idea for cell-free bone tissue engineering.     

Anomalous Lehmann Rotation of Achiral Nematic Liquid Crystal Droplets Trapped under Linearly Polarized Optical Tweezers

Continuous rotation of a cholesteric droplet under the heat gradient was observed by Lehmann in 1900. This phenomenon, the so-called Lehmann effect, consists of unidirectional rotation around the heat flux axis. We investigate this gradient heat effect using infrared laser optical tweezers. By applying single trap linearly polarized optical tweezers onto a radial achiral nematic liquid crystal droplet, trapping of the droplet was performed. However, under a linearly polarized optical trap, instead of stable trapping of the droplet with slightly deformed molecular directors along with a radial hedgehog defect, anomalous continuous rotation of the droplet was observed. Under low power laser trapping, the droplet appeared to rotate clockwise. By continuously increasing the laser power, a stable trap was observed, followed by reverse directional rotation in a higher intensity laser trap. Optical levitation of the droplet in the laser beam caused the heat gradient, and a breaking of the symmetry of the achiral nematic droplet. These two effects together led to the rotation of the droplet under linearly polarized laser trapping, with the sense of rotation depending on laser power.     

A Simple Design for Production of a Chopped Laser Output with a Reference Wave for a Lock-In Amplifier

Abstract

A chopper was constructed to modulate the output of an infrared Helium-Neon laser at 3.39 microns. The chopper was constructed to fit onto a previously constructed optical bench which houses the laser. The chopper also encompasses a number of inexpensive electrical components including an LED (the source) and a phototransistor (the detector) and the accompanying electronics to power the components and provides a reference wave of the characteristics required for the reference input of the PAR model 5101 Lock-In Amplifier.     

Laser Selection Significantly Affects Cell Viability Following Single-Cell Nanosurgery

This paper compares the viability of over 700 NG108 cells after membrane disruption either with a single 3 ns pulse at 337 nm or with a 5 ms train of 110 fs pulses (80 MHz) at 770 nm. Cell viability was monitored over a period of 12 h so as to understand the effect of laser ablation-induced cell apoptosis. The use of one-photon membrane disruption with the UV–laser resulted in ∼36% cell viability after 12 h while the use of two-photon ablation with the femtosecond laser resulted in a much higher viability of ∼79% after 12 h, which was the same within error of the ∼79% viability of cells in the control group. Changing the laser power to achieve a 90% probability of membrane disruption (PMD) from 50% PMD did not change the percentage of viable cells after 12 h, regardless of whether one- or two-photon ablation was employed. A systematic comparison between different methods of cellular ablation and their effect upon the viability of single cells has not been done before over such a long time frame. These results show the importance of laser choice when cell viability postsurgery is a concern.     

Nonlinear optical limiters of pulsed laser radiation based on carbon‐containing nanostructures in viscous and solid matrices

Results of the study of optical limiters of pulsed laser radiation based on nonlinear effects in carbon nanostructures placed into viscous and solid matrices are presented. A nonlinear optical limiting was studied by nanomaterials based on multi‐wall polyhedral carbon nanostructures (astralens) placed in a sol–gel matrix. Similar studies for single‐wall and multi‐wall carbon‐containing nanotubes placed in polymer matrices with various viscosities were performed. No additional mechanism of optical limiting due to electron structure of single‐wall carbon‐containing nanotubes at their introduction into viscous and solid composite media was found. An influence of polymer matrix composition containing carbon nanotubes (CNTs) on a threshold and ratio of attenuation of laser radiation was demonstrated. The best limiting characteristics were observed at placing CNT into polymethylsiloxane matrix. An effect of “self‐healing” of a medium after laser radiation passage through high viscous liquids was obtained. The high parameters of nonlinear optical limiting (the threshold of limiting 10^?5 J, ratio of attenuation 10³) achieved for the composite material CNT (HiPCO High‐Pressure Carbon Monoxide) and carbon nanofibers in high viscous and solid polymethylsiloxane media allow the design of protective filters for laser radiation operating in wide spectral range. Copyright © 2014 John Wiley & Sons, Ltd.     

Infrared Radiation Influence on Molt and Regeneration of Neohelice granulata Dana, 1851 (Grapsidae, Sesarminae)

This paper analyzes the influence of infrared radiation (IR) on regeneration, after autotomy of limb buds of Neohelice granulata and consequently the time molt. Eyestalks were ablated to synchronize the start of molt. Afterward, animals were autotomized of five pereopods and divided into control and irradiated groups. The irradiated group was treated for 30 min daily until molt. Limb buds from five animals of days 4, 16 and 20 were collected and histological sections were made from them. These sections were photographed and chitin and epithelium content measured. Another group was made, and after 15 days limb buds were extracted to analyze mitochondrial enzymatic activity from complex I and II. The irradiated group showed a significant reduction in molt time (19.38 ± 1.22 days) compared with the control group (32.69 ± 1.57 days) and also a significant increase in mitochondrial complex I (388.9 ± 27.94%) and II (175.63 ± 7.66%) in the irradiated group when compared with the control group (100 ± 17.90; 100 ± 7.82, respectively). However, these effects were not acompanied by histological alterations in relation to chitin and epithelium. This way, it was possible to demonstrate that IR increases complex I and II activity, reduces the time molt and consequently increases the appendage regeneration rate.     

An Injectable,Bifunctional Hydrogel with Photothermal Effects for Tumor Therapy and Bone Regeneration

Significant attention has been focused on bone tumor therapy recently. At present, the treatment in clinic typically requires surgical intervention. However, a few tumor cells remain around bone defects after surgery and subsequently proliferate within several days. Thus, fabrication of biomaterials with dual functions of tumor therapy and bone regeneration is significant. Herein, the injectable hydrogel containing cisplatin (DDP) and polydopamine‐decorated nano‐hydroxyapatite is prepared via Schiff base reaction between the aldehyde groups on oxidized sodium alginate and amino groups on chitosan. The hydrogel exhibits sustained release properties for DDP due to the immobilization of DDP via abundant functional groups on polydopamine (PDA). Additionally, given the intense absorption of PDA in the near‐infrared region, the hydrogel exhibits excellent photothermal effects when exposed to the NIR laser (808 nm). Based on the properties, the hydrogel effectively ablates tumor cells (4T1 cells) in vitro and suppresses tumor growth in vivo. Furthermore, the hydrogel promotes the adhesion and proliferation of bone mesenchymal stem cells in vitro due to the abundant functional groups on PDA and further induces bone regeneration in vivo. Therefore, the study extends research on novel biomaterials with dual functions of tumor therapy and bone regeneration.     

Development and Evaluation of Fiber Optic Probe-based Helium–Neon Low-level Laser Therapy System for Tissue Regeneration—An In Vivo Experimental Study

We report the design and development of an optical fiber probe-based Helium–Neon (He–Ne) low-level laser therapy system for tissue regeneration. Full thickness excision wounds on Swiss albino mice of diameter 15 mm were exposed to various laser doses of 1, 2, 3, 4, 6, 8 and 10 J cm⁻² of the system with appropriate controls, and 2 J cm⁻² showing optimum healing was selected. The treatment schedule for applying the selected laser dose was also standardized by irradiating the wounds at different postwounding times (0, 24 and 48 h). The tissue regeneration potential was evaluated by monitoring the progression of wound contraction and mean wound healing time along with the hydroxyproline and glucosamine estimation on wound ground tissues. The wounds exposed to 2 J cm⁻² immediately after wounding showed considerable contraction on days 5, 9, 12, 14, 16 and 19 of postirradiation compared with the controls and other treatment schedules, showing significant (P < 0.001) decrease in the healing time. A significant increase in hydroxyproline and glucosamine levels was observed for the 2 J cm⁻² irradiation group compared with the controls and other treatment groups. In conclusion, the wounds treated with 2 J cm⁻² immediately after the wounding show better healing compared with the controls.     

All-fiber-coupled laser-induced breakdown spectroscopy sensor for hazardous materials analysis

An all-fiber-coupled laser-induced breakdown spectroscopy (LIBS) sensor device is developed. A passively Q-switched Cr⁴⁺Nd³⁺:YAG microchip laser is amplified within an Yb fiber amplifier, thus generating high power laser pulses (pulse energy E_p = 0.8 mJ, wavelength λ = 1064 nm, repetition rate f_rep. = 5 kHz, pulse duration t_p = 1.2 ns). A passive (LMA) optical fiber is spliced to the active fiber of an Yb fiber amplifier for direct guiding of high power laser pulses to the sensor tip. In front of the sensor a plasma is generated on the surface to be analyzed. The plasma emission is collected by a set of optical fibers also integrated into the sensor tip. The spectrally resolved LIBS spectra are processed by application of principal component analysis (PCA) and analyzed together with the time-resolved spectra with neural networks. Such procedure allows accurate analysis of samples by LIBS even for materials with similar atomic composition. The system has been tested successfully during field measurements at the German Armed Forces test facility at Oberjettenberg.

The LIBS sensor is not restricted to anti-personnel mine detection but has also the potential to be suitable for analysis of bulk explosives and surface contaminations with explosives, e.g. for the detection of improvised explosive devices (IEDs).     

Induction of Lambda Prophage by 213 nm Laser Radiation: A Quantitative Comparison with 193 nm Excimer Radiation Using Image Analysis

Abstract— We compared the DNA damage produced by radiation from two UV laser wavelengths, 213 nm and 193 nm, with that produced by noncoherent 254 nm radiation. Following irradiation of Escherichia coli BR339, a bacteriophage lambda lysogen containing the lacZ gene, prophage induction was measured by assaying for β-galactosidase. Because of the limited penetration by UV laser wavelengths an agar overlay of the lysogen was used as the irradiation target. Irradiation of 254 nm was performed in buffer suspension followed by transfer of 5 μL spots onto assay plants. Computer image analysis was used to monitor the rate of product formation, observed as an increase in optical density of the irradiated zones on assay plates. We found that the rate of product formation was a more reproducible unit of comparison than the optical density present at the end of the reaction. Although the rate of product formation was not linearly related to enzyme concentration, the data could be fit to a simple logarithmic function. Using this method, we concluded that the DNA damaging ability of 213 nm radiation was 10 times more efficient than 193 nm radiation and about 100 times less efficient than 254 nm noncoherent radiation.     

Immunocytochemical Localization of XRCC1 and γH2AX Foci Induced by Tightly Focused Femtosecond Laser Radiation in Cultured Human Cells

To assess the prospects for using intense femtosecond laser radiation in biomedicine, it is necessary to understand the mechanisms of its action on biological macromolecules, especially on the informational macromolecule—DNA. The aim of this work was to study the immunocytochemical localization of DNA repair protein foci (XRCC1 and γH2AX) induced by tightly focused femtosecond laser radiation in human cancer A549 cells. The results showed that no XRCC1 or γH2AX foci tracks were observed 30 min after cell irradiation with femtosecond pulses of 10¹¹ W∙cm⁻² peak power density. An increase in the pulse power density to 2 × 10¹¹ W∙cm⁻² led to the formation of linear tracks consisting both of XRCC1 and γH2AX protein foci localized in the places where the laser beam passed through the cell nuclei. A further increase in the pulse power density to 4 × 10¹¹ W∙cm⁻² led to the appearance of nuclei with total immunocytochemical staining for XRCC1 and γH2AX on the path of the laser beam. Thus, femtosecond laser radiation can be considered as a tool for local ionization of biological material, and this ionization will lead to similar effects obtained using ionizing radiation.     

Laser saturation of optical transitions in a starch component: the amylose-iodine-iodide complex

Abstract— Saturation of optical absorption by an aqueous solution of the amylose-iodine-iodide complex was observed. Transmission of ruby laser radiation as a function of incident laser power density was measured and fitted to the steady-state solution of a double-absorption rate-equation model. This study gave an indirect determination of the lifetime of the first excited energy level. The material behaved as a passive Q-switch for a ruby laser.     

Analysis of photoinitiated polymerization in a membrane mimetic film using infrared spectroscopy and near-IR Raman microscopy

A method has been developed to investigate the extent of polymer cross-linking that results following in situ photopolymerization of an acrylate-functionalized phospholipid assembly adsorbed onto a stabilized, membrane-mimetic film produced from a polyelectrolyte multilayer (PEM) on polytetrafluoroethylene (PTFE) grafts. The acrylate phospholipid monomer was synthesized, prepared as a unilamellar vesicle, and fused onto closed-packed acyl chains that make up the PEM membrane-mimetic barrier on the PTFE graft. Both broad band white light and 514.5 nm laser radiation were used as excitation sources for photoinitiation; eosin Y was used as the photoinitiator. The use of 514.5 nm excitation reduced the time for maximum polymerization of the acrylate lipid from 60 min to 240 s. Infrared spectroscopy was successfully used to analyze the extent of photopolymerization in simplified model acrylate lipid systems; however, this method could not be used to analyze acrylate polymerization in heterogeneous, multicomponent PEM membrane-mimetic barriers on PTFE grafts. A near-infrared Raman microscopy method based on the ratio of the integrated areas of the CC and CN vibrations was shown to provide equivalent information to the IR method for analysis of the extent of polymerization efficiency in acrylate lipids. In addition, it proved feasible to extend this near-IR Raman method to the in situ analysis of the extent of polymerization in a stabilized acrylate lipid membrane on a PEM film in a PTFE vascular graft. This work describes a new approach for generating and analyzing the robustness of a membrane-mimetic coating on biomaterial surfaces, and may improve our ability to predict the long-term stability of polymeric membrane-mimetic films on implantable medical devices.     

Parasitological and Biochemical Efficacy of the Active Ingredients of Allium sativum and Curcuma longa in Schistosoma mansoni Infected Mice

The active ingredients allicin and curcumin have a wide range of actions against fungi, bacteria, and helminths. Therefore, the study was aimed to evaluate the efficacy of allicin (AL) and curcumin (CU) as antischistosomal drugs and their biochemical effects in normal and Schistosoma mansoni-infected mice. Praziquantel (PZQ) was administrated for two successive days while AL or CU was given for two weeks from the week 7th postinfection (PI). The possible effect of different regimens on Schistosoma worms was evaluated by measuring the percentage of the recovered worms, tissue egg load, and oogram pattern. Serum alanine transaminase activity and levels of triglycerides, cholesterol, and uric acid were measured. Liver tissue malondialdehyde and reduced glutathione levels besides, the activities of glutathione-S-transferase, superoxide dismutase and catalase were assessed for the oxidative/antioxidant condition. DNA electrophoresis of liver tissue was used to indicate the degree of fragmentation. There was a significant reduction in the recovered worms and egg load, with a marked change of oogram pattern in all treated groups with PZQ, AL, and CU in comparison with infected-untreated mice. PZQ, AL, and CU prevented most of the hematological and biochemical disorders, as well as significantly improved the antioxidant capacity and enhanced DNA fragmentation in the liver tissue of schistosomiasis mice compared to the infected-untreated group. These promising results suggest that AL and CU are efficient as antischistosomal drugs, and it would be beneficial to test their combination to understand the mechanism of action and the proper period of treatment leading to the best result.     

An EPR and Optical Spectroscopy Study of the Effect of Laser Radiation on Biological Tissues

The formation of radicals upon UV (248 nm) and IR (1.56 m) laser irradiation of some biological tissues (cartilage, bone tissue, fish scale) and their components (chondroitin sulfate, collagen) was studied by the EPR technique. The radical decay kinetics in bony tissue specimens after their irradiation with UV light were described. By the spin trapping technique, it was shown that radicals were not produced during IR (1.56 m) laser irradiation of cartilaginous tissue. A change in optical absorption spectra and the dynamics of optical density of cartilaginous tissue, fish scale, and a collagen film under exposure to laser radiation (248 nm) in an air, oxygen, and nitrogen atmosphere was studied.