Light-emitting diode photomodulation of uterine adenocarcinoma cells inhibited angiogenesis capacity via the regulation of exosome biogenesis

This study was conducted to investigate the inhibitory effects of light-emitting diodes (LEDs) on exosome biogenesis and angiogenesis capacity in Ishikawa endometrial cancer cells. To this end, cells were exposed to different energy densities (fluences) of 4, 8, 16, 32, and 64 J/cm² for 5 days (once every 24 h), and cell viability was determined using an MTT assay. Based on data from the MTT panel, cells were exposed to 4 and 16 J/cm² for subsequent analyses. Exosome biogenesis was also monitored via monitoring the expression of CD63, ALIX, and Rab27a and b. The size and morphology of exosomes in the supernatant were measured using scanning electron microscopy (SEM), and dynamic light scattering (DLS). Using Transwell insert, the migration capacity of these cells was studied. The angiogenic effects of irradiated Ishikawa cell secretome at different fluences were monitored on human endothelial cells using in vitro tubulogenesis. Results indicated LED can reduce the viability of Ishikawa cells in a dose-dependent manner. According to our data, 4 and 64 J/cm² groups exhibited minimum and maximum cytotoxic effects compared to the control cells. Data revealed a close proportional relationship between the power of laser and exosome average size compared to the non-treated control cells (p < 0.05). Real-time PCR analysis showed the suppression of Rab27b and up-regulation of Rab27a in irradiated cells exposed to 4 and 16 J/cm² (p < 0.05). These effects were evident in the 16 J/cm² group. Likewise, LED can inhibit the migration of Ishikawa cells in a dose-dependent manner (p < 0.05). Tubulogenesis activity of endothelial cells was suppressed after incubation with the secretome of irradiated Ishikawa cells (p < 0.05). These data showed tumoricidal properties of LED irradiation on human adenocarcinoma Ishikawa cells via the inhibition of exosome biogenesis and suppression of angiogenesis capacity.

LED light sources improved the essential oil components and antioxidant activity of two genotypes of lemon balm (Melissa officinalis L.)

BACKGROUND

Nowadays, light-emitting diodes (LEDs) as a new lighting technology, have been emerged as an alternative source of light for plants due to their wavelength specificity, the narrow width of their bands, small size, solid structure, long lifetime, and low heat generation. Here we investigated the effect of different LED light sources on the essential oil components and antioxidant activity of Melissa officinalis. Two genotypes of lemon balm (Ilam and Isfahan) were subjected to four artificial light treatments, including white, red, blue, red + blue LEDs, and greenhouse light as natural lighting.

RESULTS

The LED lights significantly increased shoot fresh and dry weights and leaf number in the two genotypes as compared to greenhouse condition. The results showed that the content and composition of essential oil in the two genotypes were variable under different light treatments and the total amount of compounds in the Ilam genotype was higher than the other genotype. The results of analysis of the essential oil by GC/MS indicated that the highest amount of monoterpenes in the genotypes was related to citronellal under red + blue LED lamps (15.3 and 17.2% in Ilam and Isfahan genotypes, respectively) but blue, white, and greenhouse condition had the most effect on sesquiterpenes content in both genotypes. The results showed that the observed variation between the two genotypes in the essentials oil composition was related to the relative percentage of the constituents and not to the appearance or lack of a specific component. Red + blue lighting also provided the highest radical scavenging activity in both genotypes (80.77 and 82.09% for Ilam and Isfahan genotypes, respectively). Based on principal component analyses (PCA), three main groups were identified regarding genotypes and all light treatments.

CONCLUSIONS

Overall, results indicated that the essentials oil composition of two genotypes of lemon balm was affected both qualitatively and quantitatively by different LED light sources; hence, LED lights might be used to improve monoterpenes, sesquiterpenes, and antioxidant activity in the selected genotypes.

Improvement of Unsaturated Fatty Acid Production from Porphyridium cruentum Using a Two-Phase Culture System in a Photobioreactor with Light-Emitting Diodes (LEDs)

In this study, the culture conditions for Porphyridium cruentum were optimized to obtain the maximum biomass and lipid productions. The eicosapentaenoic acid content was increased by pH optimization. P. cruentum was cultured with modified F/2 medium in 14-L photobioreactors using a two-phase culture system, in which the green (520 nm) and red (625 nm) light-emitting diodes (LEDs) were used during the first and second phases for biomass production and lipid production, respectively. Various parameters, including aeration rate, light intensity, photoperiod, and pH were optimized. The maximum biomass concentration of 0.91 g dcw/l was obtained with an aeration rate of 0.75 vvm, a light intensity of 300 μmol m^-2s^-1, and a photoperiod of 24:0 h. The maximum lipid production of 51.8% (w/w) was obtained with a light intensity of 400 μmol m^-2s^-1 and a photoperiod of 18:6 h. Additionally, the eicosapentaenoic acid and unsaturated fatty acid contents reached 30.6% to 56.2% at pH 6.0.

Investigation of LED-based photodynamic therapy efficiency on breast cancer cells

Photodynamic therapy (PDT) is based on special light source, photosensitizer (PS), and in the presence of oxygen. Different light sources have been used for PDT applications. Recent studies have focused on LED light sources for PDT applications due to reducing the cost of laser-based PDT and providing easy access for research laboratory or clinic facilities. LED-mediated PDT applications have shown promising results for the treatment of different types of disease. However, few studies have determined the effects of LED-based PDT on cancer cells. For the first time, the aim of this study was to explore the therapeutic effects of 5-aminolevulinic acid (5-ALA)-mediated PDT after LED irradiation on two sub-types (a poorly aggressive MCF-7 and a highly aggressive MDA-MB-231) of breast cancer cell lines. The effectiveness of 5-ALA PDT treatment was evaluated by WST-1, annexin V, and acridine orange staining with different energy levels. The LED system was specially developed with optical power and wavelength stability techniques. The system consists of user interface and embedded LED controller with real-time optic power output calibration by photodiode feedback. Our results demonstrated that the cell viability of breast cancer cells was considerably decreased a LED dose-dependent manner (P < 0.05). Additionally, a significant increase in the percentage of apoptotic cells was detected in breast cancer cells after irradiation with LED at a density of 18 and 30 J/cm² energy. Consequently, the LED system could be effectively used for irradiation of 5-ALA in the treatment of breast cancer cells.

Evaluation of an ultraviolet LED trap for catching Anopheles and Culex mosquitoes in south-eastern Tanzania

BACKGROUND

Improved surveillance techniques are required to accelerate efforts against major arthropod-borne diseases such as malaria, dengue, filariasis, Zika and yellow-fever. Light-emitting diodes (LEDs) are increasingly used in mosquito traps because they improve energy efficiency and battery longevity relative to incandescent bulbs. This study evaluated the efficacy of a new ultraviolet LED trap (Mosclean) against standard mosquito collection methods.

METHODS

The study was conducted in controlled semi-field settings and in field conditions in rural south-eastern Tanzania. The Mosclean trap was compared to commonly used techniques, namely CDC-light traps, human landing catches (HLCs), BG-Sentinel traps and Suna traps.

RESULTS

When simultaneously placed inside the same semi-field chamber, the Mosclean trap caught twice as many Anopheles arabiensis as the CDC-light trap, and equal numbers to HLCs. Similar results were obtained when traps were tested individually in the chambers. Under field settings, Mosclean traps caught equal numbers of An. arabiensis and twice as many Culex mosquitoes as CDC-light traps. It was also better at trapping malaria vectors compared to both Suna and BG-Sentinel traps, and was more efficient in collecting mosquitoes indoors than outdoors. The majority of An. arabiensis females caught by Mosclean traps were parous (63.6%) and inseminated (89.8%). In comparison, the females caught by CDC-light traps were 43.9% parous and 92.8% inseminated.

CONCLUSIONS

The UV LED trap (Mosclean trap) was efficacious for sampling Anopheles and Culex mosquitoes. Its efficacy was comparable to and in some instances better than traps commonly used for vector surveillance. The Mosclean trap was more productive in sampling mosquitoes indoors compared to outdoors. The trap can be used indoors near human-occupied nets, or outdoors, in which case additional CO2 improves catches. We conclude that this trap may have potential for mosquito surveillance. However, we recommend additional field tests to validate these findings in multiple settings and to assess the potential of LEDs to attract non-target organisms, especially outdoors.

Enhancement of biomass, lipids, and polyunsaturated fatty acid (PUFA) production in Nannochloropsis oceanica with a combination of single wavelength light emitting diodes (LEDs) and low temperature in a three-phase culture system

A three-phase culture system combining blue (465 nm) light-emitting diode (LED) wavelength as the first phase, green (550 nm) as the second phase, and temperature stress as the third phase was applied to a Nannochloropsis oceanica culture in 14-L photobioreactors. Microalgal growth promotion parameters were optimized in the first phase, followed by green LED stress for lipid production in the second phase. Maximum biomass and lipid production values of 0.75 gdcw L^-1 and 57.6% (w/w) were obtained at an aeration rate of 0.50 vvm, with a light intensity of 250 µmol m^-2 s^-1 and 24:0 h light/dark cycle. Culture temperatures of 15, 10 and 5 °C were applied in the third phase, where temperature stress induced the production of monounsaturated and polyunsaturated fatty acid synthesis in N. oceanica. The production of α-linolenic acid, eicosapentaenoic acid and docosahexaenoic acid increased by 52% (w/w), 96% (w/w), and 77% (w/w), respectively, at 5 °C in the third phase.

Hybrid intracerebral probe with integrated bare LED chips for optogenetic studies

This article reports on the development, i.e., the design, fabrication, and validation of an implantable optical neural probes designed for in vivo experiments relying on optogenetics. The probes comprise an array of ten bare light-emitting diode (LED) chips emitting at a wavelength of 460 nm and integrated along a flexible polyimide-based substrate stiffened using a micromachined ladder-like silicon structure. The resulting mechanical stiffness of the slender, 250-μm-wide, 65-μm-thick, and 5- and 8-mm-long probe shank facilitates its implantation into neural tissue. The LEDs are encapsulated by a fluropolymer coating protecting the implant against the physiological conditions in the brain. The electrical interface to the external control unit is provided by 10-μm-thick, highly flexible polyimide cables making the probes suitable for both acute and chronic in vivo experiments. Optical and electrical properties of the probes are reported, as well as their in vivo validation in acute optogenetic studies in transgenic mice. The depth-dependent optical stimulation of both excitatory and inhibitory neurons is demonstrated by altering the brain activity in the cortex and the thalamus. Local network responses elicited by 20-ms-long light pulses of different optical power (20 μW and 1 mW), as well as local modulation of single unit neuronal activity to 1-s-long light pulses with low optical intensity (17 μW) are presented. The ability to modulate neural activity makes these devices suitable for a broad variety of optogenetic experiments.

Effect of red and blue light emitting diodes "CRB-LED" on in vitro organogenesis of date palm (Phoenix dactylifera L.) cv. Alshakr

The objective of the present study is to determine the effect of light source on enhancement of shoot multiplication, phytochemicals, as well as, antioxidant enzyme activities of in vitro cultures of date palm cv. Alshakr. In vitro-grown buds were cultured on Murashige and Skoog (MS) medium and incubated under a conventional white fluorescent light (control), and combinations of red + blue light emitting diode (18:2) (CRB-LED). Results revealed that the treatment of CRB-LED showed a significant increase in the number of shoots compared with the white florescent light. Total soluble carbohydrate "TSCH" (7.10 mg g(-1) DW.), starch (1.63 mg g(-1) DW.) and free amino acids (2.90 mg g(-1) DW.) were significantly higher in CRB-LED (p < 0.05). Additionally, CRB-LED induced a higher peroxidase activity (25.50 U ml(-1)) compared with the white fluorescent light treatment (19.74 U ml(-1)) as control treatment. Potassium, magnesium and sodium contents in (3.62, 13.99 and 2.76 mg g(-1) DW.) were increased in in vitro shoots under CRB-LED treatment in comparison with fluorescent light (p < 0.05). Protein profile showed the appearance of newly bands with the molecular weight of 38 and 60 kDa at the treatment CRB-LED compared with control treatment. Our results demonstrate the positive effects of CRB-LED light during the course of date palm tissue cultures.

Effects of light-emitting diodes (LEDs) on the accumulation of lipid content using a two-phase culture process with three microalgae

Conditions of light-emitting diode (LED) wavelength, light intensity, nitrate concentration, and time of exposure to green LED light stress in a two-phase culture were optimized for lipid production with three species of microalgae. Among the three microalgae, Nannochloropsis oculata showed the highest specific growth rate (μmax) of 0.037h(-1) and the lowest saturation constant (Ks) of 1.32mg/L. The highest lipid contents of the three microalgae in the second phase under green LED light stress were 52.0% (w/w) for Nannochloropsis salina at 2days, 53.0% (w/w) for Nannochloropsis oceanica at 2days, and 56.0% for N. oculata at 2days. Fatty acid analysis of the microalgae showed that 85-87% (w/w) of total fatty acids from N. salina, N. oceanica, and N. oculata consisted of palmitic acid (C16:0) and oleic acid (C18:1).