Rose Bengal Solution Research Articles

Effects of Different Scleral Photo-Crosslinking Modalities on Scleral Stiffness and Hydration.

The purpose of this study was to evaluate the biomechanical and hydration differences in scleral tissue after two modalities of collagen cross-linking. Scleral tissue from 40 adult white rabbit eyes was crosslinked by application of 0.1% Rose Bengal solution followed by 80 J/cm2 green light irradiation (RGX) or by application of 0.1% riboflavin solution followed by 5.4 J/cm2 ultraviolet A irradiation (UVX). Posterior scleral strips were excised from treated and untreated sclera for tensile and hydration-tensile tests. For tensile tests, the strips were subjected to uniaxial extension after excision. For hydration-tensile tests, the strips were dehydrated, rehydrated, and then tested. Young's modulus at 8% strain and swelling rate were estimated. ANOVAs were used to test treated-induced differences in scleral biomechanical and hydration properties. Photo-crosslinked sclera tissue was stiffer (Young's modulus at 8% strain: 10.7 ± 4.5 MPa, on average across treatments) than untreated scleral tissue (7.1 ± 4.0 MPa). Scleral stiffness increased 132% after RGX and 90% after UVX compared to untreated sclera. Scleral swelling rate was reduced by 11% after RGX and by 13% after UVX. The stiffness of the treated sclera was also associated with the tissue hydration level. The lower the swelling, the higher the Young's modulus of RGX (-3.8% swelling/MPa) and UVX (-3.5% swelling/MPa) treated sclera. Cross-linking with RGX and UVX impacted the stiffness and hydration of rabbit posterior sclera. The Rose Bengal with green light irradiation may be an alternative method to determine the efficacy and suitability of inducing scleral tissue stiffening in the treatment of myopia.

Encapsulated Rose Bengal Enhances the Photodynamic Treatment of Triple-Negative Breast Cancer Cells.

Among breast cancer subtypes, triple-negative breast cancer stands out as the most aggressive, with patients facing a 40% mortality rate within the initial five years. The limited treatment options and unfavourable prognosis for triple-negative patients necessitate the development of novel therapeutic strategies. Photodynamic therapy (PDT) is an alternative treatment that can effectively target triple-negative neoplastic cells such as MDA-MB-231. In this in vitro study, we conducted a comparative analysis of the PDT killing rate of unbound Rose Bengal (RB) in solution versus RB-encapsulated chitosan nanoparticles to determine the most effective approach for inducing cytotoxicity at low laser powers (90 mW, 50 mW, 25 mW and 10 mW) and RB concentrations (50 µg/mL, 25 µg/mL, 10 µg/mL and 5 µg/mL). Intracellular singlet oxygen production and cell uptake were also determined for both treatment modalities. Dark toxicity was also assessed for normal breast cells. Despite the low laser power and concentration of nanoparticles (10 mW and 5 µg/mL), MDA-MB-231 cells experienced a substantial reduction in viability (8 ± 1%) compared to those treated with RB solution (38 ± 10%). RB nanoparticles demonstrated higher singlet oxygen production and greater uptake by cancer cells than RB solutions. Moreover, RB nanoparticles display strong cytocompatibility with normal breast cells (MCF-10A). The low activation threshold may be a crucial advantage for specifically targeting malignant cells in deep tissues.

Diversity and species composition of microbiota associated with dengue mosquito breeding habitats: A cross-sectional study from selected areas in Udapalatha MOH division, Sri Lanka

Objective: To determine the diversity of microbiota associated with different breeding habitats of dengue vector mosquitoes Aedes (Ae.) aegypti. and Ae. albopictus and to identify any parasitic, epibiont, pathogenic, competitive or predatory species. Methods: Sampling was performed from a variety of breeding habitats using dipping, pipetting and siphoning techniques. Microbiota in water samples were preserved using Rose Bengal solution and Lugol's iodine, and were identified. Live samples of microbiota were kept under laboratory conditions to observe any pathogenic or parasitic microbiota interacting with larvae. Results: A total of eleven microbiota species (Canthocamptus staphylinus, Canthocamptus microstaphylinus, Parastenocaris brevipes, Lepadella ovalis, Lepadella patella, Rotatoria rotatoria, Rotatoria macrura, Asplanchna brightwelli, Trichocerca rattus, Euglena variabilis, and Flagilaria capucina) belonging to four (4) phyla (Arthropoda, Rotifera, Euglenozoa, and Ochrophyta) and 8 microbiota species belonged to four phyla (Arthropoda, Rotifera, Euglenozoa, and Ochrophyta) were identified from Ae. aegypti and Ae. albopictus breeding habitats respectively. There was a higher percentage (54.54%) of larval habitats positive for the secondary vector Ae. albopictus than through the primary vector Ae. aegypti in the Gampola urban area indicating higher possibility of transmitting the dengue virus through the secondary vector. However, no pathogenic or parasitic ciliates on mosquito larvae were encountered in the present study. Those findings may be due to sampling maingly from temporary container-type breeding habitats. Conclusions: The relative distribution of microbiota associated with mosquito species differed significantly among Ae. aegypti and Ae. albopictus. The overall findings of this study could help in implementing novel eco-friendly vector-control strategies in the study area.

Synthesis of efficient light harvesting Cr, N Co-doped TiO2 nanoparticles for enhanced visible light photocatalytic degradation of xanthene dyes; eosin yellow and rose bengal.

To solve the problem of water pollution, using environment friendly and cost effective method in short time is the need of hour. In this work, chromium (Cr) and nitrogen (N) co-doped TiO2 nanoparticles were synthesized and were used for the photocatalytic degradation of dyes under visible light. The synergistic effect of metal and non-metal co-dopants added would result in appropriate reduction of band gap {from 3.2 eVof TiO2 to 2.67eV}, decrease in recombination rate of charge carriers by trapping electrons and holes, and in better light harvesting capacity. Nanoparticles were synthesized by sol-gel method and characterized using ultraviolet-visible (UV-VIS) spectroscopy, fourier transform infrared (FTIR) spectroscopy, atomic force microscopy (AFM), zeta potential, X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET)analysis, field emission scanning electron microscopy (FE-SEM), and RAMAN spectroscopy. Eosin yellow (EY) and rose bengal (RB) were subjected to photocatalytic degradation under solar light to check the photocatalytic activity of the synthesized nanoparticles. Effects of dye concentration, the concentration of nanoparticles, time, and pH were investigated to optimize the parameters. The results obtained were remarkable for 20ppm EY solution took 10min using 1 gL-1 NPs at pH 3 and 10ppm RB solution took 5min using 0.75 gL-1 NPs at pH 5.78 (original pH) for complete degradation. Kinetics studies were also performed and both dyes followed pseudo-second-order kinetics with R2 values 0.99312 and 0.99712 for EY and RB, respectively. The study of degraded products was conducted using high-performance liquid chromatography (HPLC) hyphenated with electron spray ionization mass spectroscopy (ESI-MS) (LC-MS) and possible degradation pathways were made for both dyes. A reusability test was also performed showing the efficiency of the particles was up to 88% after 3 cycles of use. These notable results can be attributed to the efficient removal of organic pollutants using the proposed dopants in this study.

Covalent Organic Framework as a Metal-Free Photocatalyst for Dye Degradation and Radioactive Iodine Adsorption.

Exploring a covalent organic framework (COF) material as an efficient metal-free photocatalyst and as an adsorbent for the removal of pollutants from contaminated water is very challenging in the context of sustainable chemistry. Herein, we report a new porous crystalline COF, C6-TRZ-TPA COF, via segregation of donor-acceptor moieties through the extended Schiff base condensation between tris(4-formylphenyl)amine and 4,4',4″-(1,3,5-triazine-2,4,6-triyl)trianiline. This COF displayed a Brunauer-Emmett-Teller (BET) surface area of 1058 m2 g-1 with a pore volume of 0.73 cc g-1. Again, extended π-conjugation, the presence of heteroatoms throughout the framework, and a narrow band gap of 2.2 eV, all these features collectively work for the environmental remediation in two different perspectives: it could harness solar energy for environmental clean-up, where the COF has been explored as a robust metal-free photocatalyst for wastewater treatment and as an adsorbent for iodine capture. In our endeavor of wastewater treatment, we have conducted the photodegradation of rose bengal (RB) and methylene blue (MB) as model pollutants since these are extremely toxic, are health hazard, and bioaccumulative in nature. The catalyst C6-TRZ-TPA COF showed a very high catalytic efficiency of 99% towards the degradation of 250 parts per million (ppm) of RB solution in 80 min under visible light irradiation with the rate constant of 0.05 min-1. Further, C6-TRZ-TPA COF is found to be an excellent adsorbent as it efficiently adsorbed radioactive iodine from its solution as well as from the vapor phase. The material exhibits a very rapid iodine capturing tendency with an outstanding iodine vapor uptake capacity of 4832 mg g-1.

Lagena Inferocostata – An Opportunistic Index Species of Hydrocarbon Pollutants in Gokana and Khana Local Government Areas of River State, Nigeria

Thirty shallow cores ranging from 0.0 – 1.0m and composited into upper and lower section, was studied to determine relationship between petroleum hydrocarbon pollutants and benthic foraminiferal species in order to determine an index for environmental monitoring in the study area. The core samples were taken from Gokana and Khana Local Government Areas of Rivers State, Nigeria. The cores were treated with Rose Bengal solution to distinguish between then acoenose and biocoenosis benthonic foraminiferal. The cores were analyzed for sedimentology, petroleum hydrocarbon concentrations and micropaleontology. Sedimentological descriptions of the cores indicated inhibited free flow of fluids based on the rock textures which mostly consists of clays and peaty clays. Petroleum hydrocarbons analysis consisted of Total Petroleum Hydrocarbon (TPH) and Polycyclic Aromatic Hydrocarbon (PAH). The results in concentrations of the petroleum hydrocarbons indicated higher concentrations in the upper composited sections. Total Petroleum Hydrocarbon (TPH) and Polycyclic Aromatic Hydrocarbon (PAH) ranged between (20612mg/kg – 37.09mg/kg and 9.55mg/kg – <0.01mg/kg respectively) in the upper composited section and between (14731mg/kg – 14.67mg/kg and 5.71mg/kg – <0.01mg/kg respectively) in the lower composited section. Occurrence of benthonic foraminiferal in the study samples is very low to barren among very low diversity. Three benthonic foraminiferal diversities were identified in the study samples and included Lagenainferocostata, Anomalinoidesspp and Ammodiscus spp. Benthonic foraminifera showed negative correlation with TPH/PAH in the presence of carcinogenic Polycyclic Aromatic Hydrocarbon (PAH) congeners except for Lagenainferocostata which increased consistently and significantly with increasing TPH/PAH in the two composited sections. This suggested Lagenainferocostata as an Index opportunistic species for the hydrocarbon polluted study area.

An Analysis of the Effects of In Vitro Photodynamic Therapy on Prostate Cancer Tissue by Histopathological Examination and Magnetic Resonance Imaging.

Prostate cancer can significantly shorten the lifetime of a patient, even if he is diagnosed at an early stage. The development of minimally-invasive focal therapies such as photodynamic therapy to reduce the number of neoplastic cells while sparing delicate structures is extremely advantageous for treating prostate cancer. This study investigates the effect of photodynamic therapy performed in prostate tissue samples in vitro, using quantitative magnetic resonance imaging and histopathological analysis. Prostate tissue samples were treated with oxygenated solutions of Rose Bengal (RB) or protoporphyrin IX disodium salt (PpIX), illuminated with visible light, and then analyzed for changes in morphology by microscopy and by measurement of spin–lattice and spin–spin relaxation times at 1.5 Tesla. In the treated prostate tissue samples, histopathological images revealed chromatin condensation and swelling of the stroma, and in some cases, thrombotic necrosis and swelling of the stroma accompanied by pyknotic nuclei occurred. Several samples had protein fragments in the stroma. Magnetic resonance imaging of the treated prostate tissue samples revealed differences in the spin–lattice and spin–spin relaxation times prior to and post photodynamic action.

The Impact of Different Rose Bengal Formulations on Corneal Thickness and the Efficacy of Rose Bengal/Green Light Corneal Cross-linking in the Rabbit Eye.

To examine central corneal thickness (CCT) changes during in vivo rose bengal-green light corneal cross-linking (RG-CXL) and compare the CXL efficacy of different rose bengal formulations. After epithelium removal, the right eyes of rabbits were immersed in rose bengal solution prepared by different solvents (water, phosphate buffered saline, dextran, and hydroxypropyl methylcellulos [HPMC]) for 2 or 20 minutes, then the rose bengal distribution in the corneal stroma was analyzed by confocal fluorescence detection. During the RG-CXL process, the CCT was measured at seven time points. The left eyes served as the untreated control group. Corneal enzymatic resistance and corneal biomechanics were tested to compare the RG-CXL efficacy. The rose bengal infiltration depths were 120 and 200 µm for the 2- and 20-minute groups, respectively. CCT increased significantly after infiltration, then decreased significantly in the first 200 seconds of irradiation and decreased slowly for the next 400 seconds. The CCT of the 20-minute groups was significantly thicker than that of the 2-minute groups (P < .0001). All RG-CXL treatments improved the corneal enzymatic resistance and corneal biomechanics, with the effects being greater in the 20-minute groups. The inclusion of 1.1% HPMC in the rose bengal formulation helped to maintain CCT during irradiation while not affecting either the infiltration of rose bengal or the efficacy of RG-CXL. Within the range studied, RG-CXL efficacy increased with infiltration time. The incorporation of a 20-minute infiltration of 0.1% rose bengal-1.1% HPMC into the RG-CXL procedure may further improve the safety of the treatment and its prospects for clinical use. [J Refract Surg. 2022;38(7):450-458.].

Assemblages of Benthic Foraminifera in Pujada Island, Davao Oriental, Philippines

The present study investigated the composition, density, abundance, and diversity of benthic foraminifera, and their relationship with various physico-chemical parameters such as pH, salinity, temperature, and sediment grain size. Foraminifera were collected from the intertidal zone using sediment cores and extracted from the sediments through sieving. The extracted foraminifera were stained with Rose bengal solution and preserved with buffered formalin. A total of 9,459 individuals of foraminifera were identified, consisting of 39 species classified into four orders, 16 families, and 21 genera. The top three most abundant genera were Calcarina, Baculogypsina, and Amphistegina. The comparison (ANOVA) of the abundance of foraminifera among the six stations revealed highly significant differences (P= 0.000; df= 38). Station 1 exhibited the highest diversity of foraminifera on Pujada Island, as indicated by an H’ value of 3.06. Conversely, station 6 displayed the lowest diversity, with an H’ value of 1.59. The pH, salinity, and temperature values are all within acceptable limits for seawater. The decreased diversity observed in some stations are attributed by various factors, like site disturbance (accessibility to many tourists and availability of beach resorts) and the variation in sediment grain size composition. The findings suggest that generally, Pujada Island remains an undisturbed coastal area. As a result, this study provides a baseline for future monitoring of the impacts of natural and human-induced activities in the region, thereby recommending the use of foraminifera's as bioindicators for marine health.&#x0D;

MP49-19 TIME COURSE CHANGES IN VOIDING INTERVAL IN RATS WITH FOCAL CEREBRAL INFARCTION INDUCED BY PHOTOCHEMICALLY-INDUCED THROMBOSIS

You have accessJournal of UrologyCME1 May 2022MP49-19 TIME COURSE CHANGES IN VOIDING INTERVAL IN RATS WITH FOCAL CEREBRAL INFARCTION INDUCED BY PHOTOCHEMICALLY-INDUCED THROMBOSIS Yuya Ota, Yasue Kubota, Yuji Hotta, Mami Matsumoto, Nayuka Matsuyama, Taiki Kato, Takashi Hamakawa, Tomoya Kataoka, Kazunori Kimura, Kazunobu Sawamoto, and Takahiro Yasui Yuya OtaYuya Ota More articles by this author , Yasue KubotaYasue Kubota More articles by this author , Yuji HottaYuji Hotta More articles by this author , Mami MatsumotoMami Matsumoto More articles by this author , Nayuka MatsuyamaNayuka Matsuyama More articles by this author , Taiki KatoTaiki Kato More articles by this author , Takashi HamakawaTakashi Hamakawa More articles by this author , Tomoya KataokaTomoya Kataoka More articles by this author , Kazunori KimuraKazunori Kimura More articles by this author , Kazunobu SawamotoKazunobu Sawamoto More articles by this author , and Takahiro YasuiTakahiro Yasui More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000002624.19AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: The Photochemically-induced thrombosis (photothrombosis), which is easy to implement and minimally invasive, can create focal cerebral infarcts in the superficial layers of the cerebrum. Using this, we aimed to establish a new rat model of increases in urinary frequency after focal cerebral infarction, characterized by its simplicity, nonlethal nature, and high reproducibility. METHODS: A total of 90 11-week-old female Wistar-ST rats were assigned to the sham or photothrombosis-treated (PT) group. Photothrombosis was used to induce focal infarcts in the prefrontal and anterior cingulate cortices, which are involved in lower urinary tract control. A fiber optic cable delivering a light source was placed stereotactically onto the skull 1 mm anterior to the bregma on the midline. Rose Bengal solution (30 mg/mL/kg) was injected into the tail vein, and the skull was irradiated. Neurological, cystometric, and immunohistochemical evaluation of the brain were performed preoperatively and on postoperative days 1, 7, 14, and 28. RESULTS: Cystometric analysis indicated that micturition intervals significantly shortened in photothrombosis-treated rats compared with that in the sham group on Days 1 and 7 (P < 0.01), and prolonged after 14 days, with no difference between the groups (Figure A). Baseline pressure, micturition threshold pressure, and maximum intravesical pressure did not differ between the groups. Neurological evaluation revealed that only motor disturbances in the hind limbs improved with time in the PT group. Immunopathological evaluation revealed an accumulation of activated microglia, and subsequent increase in reactive astrocytes, at the peri-infarct zone after photothrombotic stroke. Throughout the study, all postphotothrombosis rats showed cerebral infarction in the prefrontal cortex and anterior cingulate cortex; no rats showed fatal cerebral infarction. CONCLUSIONS: This novel photothrombosis model, combining non-lethality and high reproducibility, observed changes in micturition status. This photothrombosis method may be able to contribute to the understanding of neural control of urinary function by regulating the number and volume of the infarcted areas. Source of Funding: GSK Japan Research Grant 2019 © 2022 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 207Issue Supplement 5May 2022Page: e861 Advertisement Copyright & Permissions© 2022 by American Urological Association Education and Research, Inc.MetricsAuthor Information Yuya Ota More articles by this author Yasue Kubota More articles by this author Yuji Hotta More articles by this author Mami Matsumoto More articles by this author Nayuka Matsuyama More articles by this author Taiki Kato More articles by this author Takashi Hamakawa More articles by this author Tomoya Kataoka More articles by this author Kazunori Kimura More articles by this author Kazunobu Sawamoto More articles by this author Takahiro Yasui More articles by this author Expand All Advertisement PDF DownloadLoading ...

Photonic Crystal-Enhanced Photodynamic Antibacterial Therapy

Photonic Crystal-Enhanced Photodynamic Antibacterial Therapy

Enhanced synergistic catalysis by a light-harvesting binary organic dyes system based on FRET for cross-dehydrogenative-coupling reaction

Rose bengal (RB) showed photocatalytic performance for cross dehydrogenative-coupling (CDC) reaction. However, single organic dye only absorbs light of specific wavelength which results a lower light utilization efficiency. In this paper, we proposed a simple and effective approach based on Förster resonance energy transfer (FRET), to improve the performance of RB through the incorporation of rhodamine 6G (Rh6G) into RB solution and constructing a binary dyes system rhodamine 6G-rose bengal (Rh6G-RB). The energy transfer efficiency and antenna effect of Rh6G-RB were up to 58% and 10.8, respectively. The synergistic effect of RB and Rh6G exhibited excellent catalytic performance under low concentration (10−5 M). The catalytic rate constant (kd) for Rh6G-RB reached 0.026 mol/(L·min) at 35 °C for aza-Henry reaction of tertiary amines with nitromethane, which was 2.03 and 5.52 times higher than that of single RB and Rh6G respectively. Moreover, the synergy of Rh6G and RB was also observed in Mannich reaction of N-tertiary amine derivatives with acetone, which all afforded the coupling products with good to excellent conversions. Finally, the Rh6G-RB system was also demonstrated an efficient visible light photoredox catalyst in continuous flow fashion. The research opened a new avenue and convenient for developing of binary or ternary organic dyes systems based on FRET and advance the application of these dye systems in photocatalytic organic synthesis.

Extraction of radium and actinium with Pb resin and Rose Bengal

The extraction of radium and actinium with Eichrom Pb resin and Rose Bengal has been studied. Radium and actinium both show a strong affinity (k’ > 10,000) for the resin at intermediate pHs (~ 5–7) from solutions with Rose Bengal. The pH range and magnitude of uptake for both radium and actinium is significantly increased by the presence of Rose Bengal compared to basic solutions without this counter ion. Radium uptake is extremely fast from basic solutions with and without Rose Bengal; actinium uptake is slower, particularly in solutions without Rose Bengal. Column studies show that despite the similar behavior of actinium and radium in this system, separations of these two elements with Pb resin and Rose Bengal solutions are possible with reasonable yields due to the differences in uptake kinetics.

Detection of singlet oxygen luminescence for experimental corneal rose bengal photodynamic antimicrobial therapy.

Rose bengal photodynamic antimicrobial therapy (RB-PDAT) treats corneal infection by activating rose bengal (RB) with green light to produce singlet oxygen (1O2). Singlet oxygen dosimetry can help optimize treatment parameters. We present a 1O2 dosimeter for detection of 1O2 generated during experimental RB-PDAT. The system uses a 520 nm laser and an InGaAs photoreceiver with bandpass filters to detect 1O2 luminescence during irradiation. The system was validated in RB solutions and ex vivo in human donor eyes. The results demonstrate the feasibility of 1O2 dosimetry in an experimental model of RB-PDAT in the cornea.

Noninvasive Photochemical Sealing for Achilles Tendon Rupture by Combination of Upconversion Nanoparticles and Photochemical Tissue Bonding Technology.

Photochemical tissue bonding (PTB), based on photosensitizer rose bengal (RB) and green light, has been regarded as an effective alternative to surgical suture and has been reported to provide benefits for Achilles tendon repair. Limited to the poor penetration of green light, secondary damage still exists while applying PTB for closed Achilles tendon rupture. This study is aimed at exploring the effects of noninvasive photochemical sealing on Achilles tendon rupture by the combination of PTB and upconversion nanoparticles (UCNPs). The rare-earth UCNPs of NaYF4 : Yb/Er (Y : Yb : Er = 78 : 20 : 2) were fabricated and then loaded into Chitosan/β-GP hydrogel containing RB to prepare UCNPs@RB/Chitosan/β-GP hydrogel. The properties of UCNPs and UCNP/Chitosan/β-GP hydrogel were characterized by TEM, SEM, DLS, and FTIR analysis. The effects of UCNP and PTB combination were evaluated in an Achilles tendon rupture rat model using histological analysis. Bioluminescence imaging of ROS was performed to explore the potential mechanism. UCNPs had a uniform shape with a diameter of 29.7 ± 2.6 nm. The UCNPs@RB/Chitosan/β-GP hydrogel could upconvert the near-infrared light into green light. The results of histological assessment showed that compared with traditional suture repair, the rats injected with UCNPs@RB/Chitosan/β-GP hydrogel followed by irradiating with near-infrared light and the rats treated with RB solution followed by irradiating with green light had better effects on Achilles tendon repair. The benefits might be related to the generation of ROS in the PTB process. These findings indicated that the combination of PTB and UCNPs@RB/Chitosan/β-GP hydrogel could be used as a noninvasive photochemical sealing for Achilles tendon rupture.

Rose bengal photodynamic antimicrobial therapy to inhibit Pseudomonas aeruginosa keratitis isolates.

To evaluate the in vitro efficacy of rose bengal and riboflavin photodynamic antimicrobial therapy for inhibition the growth of four Pseudomonas aeruginosa (P. aeruginosa) isolates. Four different clinical P. aeruginosa isolates were collected from patients with confirmed keratitis. Each strain was mixed with either sterile water, 0.1% riboflavin solution, or 0.1% rose bengal solution to yield a final bacteria concentration of 1.5 × 107CFU/mL. Aliquots from each suspension were plated onto nutrient agar in triplicate. Plates were separated into two groups: (1) no irradiation and (2) 5.4J/cm2 of radiant exposure with custom-made LED irradiation sources. Separate irradiation sources were used for each photosensitizer. The riboflavin groups used a UV-A light source (375nm) and rose bengal groups used a green light source (525nm). Plates were photographed at 72h and custom software measured bacterial growth inhibition. Growth inhibition to riboflavin and rose bengal PDAT showed strain-dependent variability. All four strains of P. aeruginosa showed greatest growth inhibition (89-99%) in the green irradiated-rose bengal group. The UV-A-irradiated riboflavin showed inhibition of 24-44%. UV-A irradiation only showed minimal inhibition (7-14%). There was little inhibitory effect in the non-irradiated photosensitizer groups. Rose bengal PDAT had the greatest inhibitory effect on all four P. aeruginosa isolates. In the UV-A-irradiated riboflavin group, there was moderate inhibition within the irradiation zone; however, there was no inhibition in the non-irradiated groups. These results suggest that rose bengal PDAT may be an effective alternative treatment for Pseudomonas aeruginosa infections.

Development of mixed matrix ZIF-8/polyvinylidene fluoride membrane with improved performance in solvent resistant nanofiltration

In the present study, the incorporation of zeolitic imidazolate framework 8 (ZIF-8) as an inorganic additive in the matrix of polyvinylidene fluoride (PVDF) membranes was investigated. The ZIF-8/PVDF mixed matrix membranes were prepared with 5, 10. 15, 20, and 25 wt% ZIF-8 and characterized using SEM, EDX, and AFM analyses. The fabricated membranes then were utilized in solvent resistant nanofiltration (SRNF) process for removal of Rose Bengal (RB) from ethanol and isopropanol (IPA). The modified mixed matrix membranes (MMMs) containing 25 wt% of ZIF-8 represented a rejection of 99.5% for RB solution in the IPA, which is 15% more than the bare PVDF membrane. 4.1% flux reduction was observed for blended membranes with 25 wt% of ZIF-8 during filtration of RB solution in the IPA, whereas this reduction was 16.1% for the bare PVDF membrane. The results of swelling studies revealed that the ZIF-8 modified membranes had a lower swelling degree in both ethanol and IPA solvents compared with bare PVDF due to the reduced available space for the diffusion of large molecules.

Morphological and morphometric characterization of domestic cat epididymal sperm.

Sperm morphometry is the tool that confers objectivity to the morphological evaluation by accurately measuring the dimensions of the gamete and its structures. Thus, the aim of the study was to perform a morphometric characterization of the domestic cat sperm. Therefore, sperm samples were collected from twenty pairs of epididymis in a TRIS extender at 37ºC. An aliquot of the sample was used to make a smear with Rose Bengal solution, and afterwards, the morphology and morphometry were analysed. In the morphology, were quantified the percentage of normal sperm cells, morphological changes of head, midpiece and tail. In morphometry, each normal sperm cell was measured for length, width, area and perimeter of head and midpiece, tail length and total length. The parameters ellipticity, elongation, regularity and rugosity were also determined. The percentage of normal sperm was 67.21%. Of the abnormalities, the curled/folded tail, followed by the curved midpiece, abnormal shaped head and detached head were the most quantified. The sperm head presented 5.56±0.01μm and 3.10±0.01μm of length and width, respectively. The head area was 16.94±0.05μm2 , while the perimeter was 16.16±0.03μm. In the derived parameters, the values were as follows: ellipticity of 1.81±0.00; elongation of 21.39±0.12; regularity of 0.81±0.00; and rugosity of 0.14±0.00. The midpiece presented length and width of 7.96±0.01μm and 0.76±0.01μm, respectively. The mean length of the sperm tail was 45.12±0.06μm, and the total cell size was 58.67±0.06μm. Thus, it was concluded that the cat sperm is an elongated cell, with high rugosity and regularity. The spermatic tail represents more than ¾ of the total length of the cell and the midpiece exceeds the length of the head.

Macroinvertebrates’ Pollution Tolerance Index in Calabar River, Cross River State, Nigeria

A study was undertaken to determine the macroinvertebrates pollution tolerance index (PTI) in Calabar River, Cross River state, Nigeria. Five sampling stations were chosen along the river course: Ikot Okon Abasi, Tinapa, Unicem, Marina resort and Nsidung beach which were labeled stations 1, 2, 3, 4 and 5 respectively. Physico-chemical parameters; surface water temperature, pH, dissolved oxygen (DO), biochemical oxygen demand (BOD), total dissolved solids (TDS) and total suspended solids (TSS) were measured using their respective meters while macroinvertebrates were sampled using a Van Veen grab, stained with Rose Bengal solution and identified under microscope. Macroinvertebrates pollution tolerance index was obtained using online software designed by Northern Kentucky Univeristy and Leaf Pack Network Biotic and Water Quality Calculator. The results obtained for physicochemical parameters showed the highest temperature as 29.90C in station five while the lowest was 26.40C in station one. pH was highest (6.60) in station five and lowest (5.52) in station one. DO was highest (4.4mg/L) in station four and lowest (3.0 mg/L) in station five while BOD was highest (3.2 mg/L) in station three and lowest (0.3 mg/L) in station one. An average total of 5366 macroinvertebrate individuals were encountered belonging to nine families and eleven species. Tubificidae had the lowest occurrence with 18 individuals which made up 0.3% of the total macroinvertebrates while Penaeidae had the highest occurrence with 2,455 individuals constituting 45.8% of the total count. Pollution tolerance index was highest (21) in station five and lowest (9) in station four with the water quality being generally poor. Hence, it is suggested that anthropogenic activities should be regulated and continuous monitoring of the river course should be carried out.

Cellular and molecular assessment of rose bengal photodynamic antimicrobial therapy on keratocytes, corneal endothelium and limbal stem cell niche

Rose Bengal Photodynamic Antimicrobial Therapy (RB-PDAT) is a novel potential treatment for progressive infectious keratitis. The principle behind this therapy is using Rose Bengal as a photosensitizer that can be activated by green light and results in the production of oxygen free radicals which in turn eradicate the microorganism. Given RB-PDAT's mechanism of action and the potential cytotoxic effects, concerns regarding the safety of this technique have arisen. The purpose of this study was to evaluate the effect of RB-PDAT on keratocytes, while focusing on the safety profile that the photo-chemical reaction has on the limbal stem cell (LSC) niche and endothelial cell layer of the treated cornea. To perform RB-PDAT, Rose Bengal solution (0.1% RB in BSS) was applied to the right cornea of rabbits for 30 min and then irradiated by a custom-made green LED light source (525 nm, 6 mW/cm2) for 15 min (5.4 J/cm2). Three rabbits were sacrificed and enucleated after 24 h for evaluation. TUNEL assay and immunohistochemistry for endothelium and limbal stem cell viability were performed on whole mounts and frozen sections in treated and control eyes. LSC of both eyes were isolated and cultured to perform MTT viability and proliferation, and scratch wound healing assays under time-lapse microscopy. Interestingly, while Rose Bengal dye penetration was superficial, yet associated cellular apoptosis was evidenced in up to 1/3 of the stromal thickness on frozen sections. TUNEL assay on whole mounts showed no endothelial cell death following treatment. Immunohistochemistry on frozen sections of LSC displayed no structural difference between treated and non-treated eyes. There was no difference in LSC proliferation rates and scratch wound healing assay demonstrated adequate cell migration from treated and non-treated eyes. The current study suggests that even though penetration of the RB dye has been shown to be limited, oxidative stress produced by RB-PDAT can reach deeper into the corneal stroma. Nevertheless, our results show that performing RB-PDAT is safe on the corneal endothelium and has no effect on LSC viability or function.