Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 1.155
Filtrar
1.
J Refract Surg ; 37(9): 631-635, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34506235

RESUMO

PURPOSE: To evaluate corneal stiffening in porcine eyes induced by corneal cross-linking (CXL) using riboflavin dissolved in either aqueous dextran or hydroxypropyl methylcellulose (HPMC) solution. METHODS: Fifty-one porcine corneas were divided into three groups of 17 each. After deepithelialization, the first (Dresden) group was treated for 30 minutes with 0.1% riboflavin (riboflavin-5-monophosphate in 0.9% NaCl) dissolved in hypertonic 20% dextran and the second (HPMC) group for 30 minutes with isotonic solution containing 0.1% riboflavin and 1.1% HPMC. Thereafter, corneas of both groups were irradiated using 5.4 J/cm2 (irradiance of 9 mW/cm2 for 10 minutes; 10*9). After CXL, all corneas were kept in an isotonic 16% dextran bath for 2 hours to obtain an equal hydration state. The third group served as the control group. Stress-strain measurements were performed on 5-mm-wide strips. Corneal thickness was monitored throughout the entire course of the experiments. RESULTS: The required stress for a 10% strain was increased by 83% in the Dresden group and 35% in the HPMC group compared to the control group. Resultant Young's modulus (at 10% strain) was 2.53 ± 0.73, 1.87 ± 0.50, and 1.47 ± 0.44 Pa for the Dresden, HPMC, and control groups, respectively. The differences between the Dresden and HPMC groups (P = .006), the Dresden and control groups (P < .001), and the HPMC and control groups (P = .014) were statistically significant. Pachymetry measurements showed a significantly increased corneal thickness after application of HPMC compared with the Dresden group (P = .002) and control group (P = .041). CONCLUSIONS: The biomechanical stiffening of the cornea by CXL can be achieved using dextran- and HPMC-based riboflavin solutions in porcine corneas with an application time of 30 minutes. Dextran-based riboflavin solutions seem to induce a slightly stronger biomechanical response in this setting. HPMC solutions induce less thinning than dextran solutions. [J Refract Surg. 2021;37(9):631-635.].


Assuntos
Substância Própria , Dextranos , Animais , Fenômenos Biomecânicos , Colágeno , Córnea , Reagentes para Ligações Cruzadas , Derivados da Hipromelose , Fármacos Fotossensibilizantes , Riboflavina/farmacologia , Suínos , Raios Ultravioleta
2.
Transfusion ; 61 Suppl 1: S101-S110, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-34269459

RESUMO

BACKGROUND: There is a global increase in whole blood usage and at the same time, emerging pathogens give cause for pathogen reduction technology (PRT). The Mirasol PRT has shown promising results for plasma and platelet concentrate products. Treatment of whole blood with subsequent platelet survival and recovery analysis would be of global value. STUDY DESIGN AND METHODS: A two-arm, open-label laboratory study was performed with 40 whole blood collections in four groups: non-leukoreduced non-PRT-treated, non-leukoreduced PRT-treated, leukoreduced non-PRT-treated, and leukoreduced PRT-treated. Leukoreduction and/or PRT-treatment was performed on the day of collection, then all WB units were stored at room temperature for 24 h. Sampling was performed after hold-time and after 24-h storage in RT. If PRT-treatment or leukoreduction, samples were also taken subsequently after treatment. Thirteen healthy volunteer blood donors completed the in vivo study per protocol. All WB units were non-leukoreduced and PRT-treated. Radioactive labeling of platelets from RT-stored, PRT-treated whole blood, sampling of subjects, recovery, and survival calculations were performed according to the Biomedical Excellence for Safer Transfusion Collaborative protocol. RESULTS: In vitro characteristics show that PRT-treatment leads to increased levels of hemolysis, potassium, and lactate, while there are decreased levels of glucose, FVIII, and fibrinogen after 24 h of storage. All values are within requirements for WB. In vivo recovery and survival of platelets were 85.4% and 81.3% of untreated fresh control, respectively. CONCLUSIONS: PRT-treatment moderately reduces whole blood quality but is well within the limits of international guidelines. Recovery and survival of platelets are satisfactory after Mirasol treatment.


Assuntos
Plaquetas/efeitos dos fármacos , Plaquetas/efeitos da radiação , Segurança do Sangue , Fármacos Fotossensibilizantes/farmacologia , Riboflavina/farmacologia , Raios Ultravioleta , Plaquetas/citologia , Preservação de Sangue , Humanos , Testes de Função Plaquetária , Fatores de Tempo
3.
Biomed Pharmacother ; 141: 111823, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34147902

RESUMO

Here, we demonstrate that the two distinct formulations of our anti-sepsis drug candidate Rejuveinix (RJX), have a very favorable safety profile in Wistar Albino rats at dose levels comparable to the projected clinical dose levels. 14-day treatment with RJX-P (RJX PPP.18.1051) or RJX-B (RJX-B200702-CLN) similarly elevated the day 15 tissue levels of the antioxidant enzyme superoxide dismutase (SOD) as well as ascorbic acid in both the lungs and liver in a dose-dependent fashion. The activity of SOD and ascorbic acid levels were significantly higher in tissues of RJX-P or RJX-B treated rats than vehicle-treated control rats (p < 0.0001). There was no statistically significant difference between tissue SOD activity or ascorbic acid levels of rats treated with RJX-P vs. rats treated with RJX-B (p > 0.05). The observed elevations of the SOD and ascorbic acid levels were transient and were no longer detectable on day 28 following a 14-day recovery period. These results demonstrate that RJX-P and RJX-B are bioequivalent relative to their pharmacodynamic effects on tissue SOD and ascorbic acid levels. Furthermore, both formulations showed profound protective activity in a mouse model of sepsis. In agreement with the PD evaluations in rats and their proposed mechanism of action, both RJX-P and RJX-B exhibited near-identical potent and dose-dependent anti-oxidant and anti-inflammatory activity in the LPS-GalN model of ARDS and multi-organ failure in mice.


Assuntos
Ácido Ascórbico/química , Ácido Ascórbico/uso terapêutico , Sulfato de Magnésio/química , Sulfato de Magnésio/uso terapêutico , Niacinamida/química , Niacinamida/uso terapêutico , Ácido Pantotênico/química , Ácido Pantotênico/uso terapêutico , Piridoxina/química , Piridoxina/uso terapêutico , Riboflavina/química , Riboflavina/uso terapêutico , Sepse/tratamento farmacológico , Sepse/metabolismo , Tiamina/química , Tiamina/uso terapêutico , Animais , Anti-Inflamatórios/química , Anti-Inflamatórios/farmacologia , Anti-Inflamatórios/uso terapêutico , Antioxidantes/química , Antioxidantes/farmacologia , Antioxidantes/uso terapêutico , Ácido Ascórbico/farmacologia , Cães , Relação Dose-Resposta a Droga , Combinação de Medicamentos , Composição de Medicamentos , Feminino , Humanos , Lipopolissacarídeos/toxicidade , Sulfato de Magnésio/farmacologia , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Niacinamida/farmacologia , Estresse Oxidativo/efeitos dos fármacos , Estresse Oxidativo/fisiologia , Ácido Pantotênico/farmacologia , Piridoxina/farmacologia , Ratos , Ratos Sprague-Dawley , Ratos Wistar , Riboflavina/farmacologia , Sepse/patologia , Superóxido Dismutase/metabolismo , Tiamina/farmacologia
4.
Transl Vis Sci Technol ; 10(5): 3, 2021 04 29.
Artigo em Inglês | MEDLINE | ID: mdl-34003976

RESUMO

Purpose: Surgery is the standard treatment for floppy eyelid syndrome, but crosslinking (CXL) tarsus has recently been proposed as an alternative. To the best of our knowledge, this study is the first to use second-harmonic generation (SHG) microscopy to examine tarsal collagen ex vivo before and after photo-activated crosslinking. To quantify crosslinking, this study examined fluorescence recovery after photobleaching (FRAP), which indirectly measures tissue stiffness. Methods: Upper eyelid tarsal plates were dissected from 21 Sprague-Dawley rats (total of 42 tarsal plates). Six normal plates were sent for histopathology and SHG imaging; the remaining 36 were crosslinked with phosphate-buffered saline (PBS) alone or riboflavin in PBS (concentrations of 0.1%, 0.3%, and 0.5%). Tissues were irradiated with 365-nm ultraviolet A light (power, 0.45 mW/cm2) for 30 minutes and immediately underwent SHG microscopy. Stiffness was indirectly measured with FRAP using fluorescein isothiocyanate (FITC)-dextran. Results: SHG imaging of normal tarsus showed that the organization of collagen bundles is complex and varies greatly depending on location. After crosslinking with high-concentration riboflavin (0.5%), collagen fibers showed clear structural changes, becoming more densely packed and wavier compared to control. FRAP half-time to fluorescence recovery was significantly increased (P < 0.05), indirectly indicating increased tissue stiffness. No structural changes were observed after crosslinking with lower riboflavin concentrations of 0.1% and 0.3%. Conclusions: This is the first report of SHG microscopy used to image tarsus collagen before and after crosslinking. These results highlight collagen structural changes, with effects on tissue stiffness indirectly confirmed by FRAP. Translational Relevance: Collagen fibers in the tarsus may be a therapeutic target for crosslinking in order to treat symptomatic floppy eyelid syndrome.


Assuntos
Tornozelo , Riboflavina , Animais , Colágeno , Reagentes para Ligações Cruzadas , Ratos , Ratos Sprague-Dawley , Riboflavina/farmacologia
5.
Exp Eye Res ; 206: 108542, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33744258

RESUMO

The aim of the study was to investigate the effectiveness of exogenous recombinant human decoron and an accompanying penetration-enhancing solution in stiffening ex-vivo porcine corneas both transepithelially and after de-epithelialization. Eight porcine paired eyes were treated transepithelially: one eye with a pre-treatment solution (Pre-Tx), penetration enhancing solution (PE), and decoron while the fellow eye was treated by the same protocol but without decoron. A second group included 4 de-epithelialized pairs treated identically. The final group included 4 de-epithelialized pairs with one eye treated with Pre-Tx, PE, and decoron while the fellow eye was treated without PE. Uniaxial tensile testing was used to compare the corneal stiffness between the different treatment conditions. Residual tissue underwent immunohistochemistry analysis to evaluate the depth of penetration of decoron into the corneal stroma. There was no stiffening effect exhibited among corneas treated transepithelially with decoron compared to control (P > 0.05) and poor stromal penetration was exhibited on tissue analysis. Among de-epithelialized corneas, there was a significant stiffening effect seen in those treated with decoron at 3%, 4%, 5%, & 6% strain (P < 0.05) compared to control. Among de-epithelialized corneas there was also a significant stiffening effect seen in those treated with the PE and decoron at 4%, 5%, & 6% strain (P < 0.05) with improved stromal penetration confirmed by immunohistochemistry, versus without PE. De-epithelialization is necessary for effective stromal penetration of decoron. Depth of penetration and subsequent corneal stiffening may be improved with a penetration enhancing solution. Compared to riboflavin, decoron requires shorter treatment time and spares UV light exposure.


Assuntos
Colágeno/farmacologia , Substância Própria/efeitos dos fármacos , Reagentes para Ligações Cruzadas/farmacologia , Ceratocone/tratamento farmacológico , Riboflavina/farmacologia , Animais , Substância Própria/patologia , Substância Própria/fisiopatologia , Modelos Animais de Doenças , Elasticidade , Epitélio Corneano/efeitos dos fármacos , Epitélio Corneano/patologia , Epitélio Corneano/fisiopatologia , Ceratocone/patologia , Ceratocone/fisiopatologia , Fármacos Fotossensibilizantes/farmacologia , Suínos , Raios Ultravioleta
6.
Transfusion ; 61(4): 1235-1246, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33694171

RESUMO

BACKGROUND: The combination of pathogen reduction technologies (PRTs) and cryopreservation can contribute to building a safe and durable platelet (PLT) inventory. Information about cryopreserved riboflavin and UV light-treated PLTs is scarce. STUDY DESIGN AND METHODS: Twenty-four buffy coat (BC) PLT concentrates were grouped into 12 type-matched pairs, pooled, and divided into 12 non-PRT-treated control units and 12 riboflavin and UV light PRT-treated test units. Both were cryopreserved with 5% DMSO and stored at -80°C for 1 year. The cryopreservation method used was designed to avoid the formation of aggregates. PLT variables (PLT recovery, swirling, pH, MPV, and LDH) and hemostatic function measured by thromboelastography (TEG) were analyzed before cryopreservation (day 1) and post-cryopreservation at day 14 and months 3, 6, and 12 of storage at -80°C. The analyses were carried out within 1-h post-thaw. RESULTS: No aggregates were found in either PLT group at any time. Swirling was observed in both groups. MPV increased and mean pH values decreased over time (p < .001), but the mean pH value was never below 6.4 in either group after 12 months of storage at -80°C. PLT recovery was good and clotting time became significantly shorter over the storage period in both groups (p < .001). CONCLUSION: Our cryopreservation and thawing method prevented aggregate formation in cryopreserved riboflavin-UV-light-treated PLTs, which exhibited good recovery, swirling, pH > 6.4, and procoagulant potential, as evidenced by a reduced clotting time after 12 months of storage at -80°C. The clinical relevance of these findings should be further investigated in clinical trials.


Assuntos
Plaquetas/efeitos dos fármacos , Preservação de Sangue/métodos , Riboflavina/farmacologia , Raios Ultravioleta/efeitos adversos , Coagulação Sanguínea/fisiologia , Plaquetas/efeitos da radiação , Criopreservação , Hemostasia/fisiologia , Humanos , Fármacos Fotossensibilizantes/farmacologia , Tromboelastografia/métodos , Fatores de Tempo
7.
Transfusion ; 61(5): 1562-1569, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33687079

RESUMO

BACKGROUND: Bacterial contamination of platelet concentrates (PCs) is the predominant cause of infectious transfusion reactions. The Pathogen Inactivation Mirasol system was implemented at the King Faisal Specialist Hospital (Saudi Arabia) to reduce the risk of transfusing contaminated PCs. This pilot study evaluated the effectiveness of Mirasol against Klebsiella pneumoniae, a pathogen associated with transfusion reactions, in whole blood-derived PCs. STUDY DESIGN AND METHODS: Whole blood (WB) units inoculated with one of six K. pneumoniae strains (five clinical isolates and ATCC-700603) at a concentration of 3-38 CFU/unit, were processed using the platelet-rich plasma (PRP) method. Each spiked PC was pooled with four unspiked units. The pooled PC was split into three Mirasol storage bags: an untreated unit (control), and two units treated with Mirasol at 26 and 32 h post-WB collection, respectively. PC samples obtained before and after Mirasol treatment were used for BacT/ALERT cultures and determination of bacteria quantification. Each experiment was repeated three independent times. RESULTS: Five strains were detected prior to PC treatment (24 h post-WB spiking), while one clinical isolate was not detected. Mirasol treatment after 26 h of WB collection resulted in complete inactivation of all K. pneumoniae strains. However, treatment 32 h post-WB collection resulted in the breakthrough of one clinical isolate in two of the three replicates with ~7.8 log10 CFU/unit detected on day 5 of PC storage. CONCLUSION: Delayed Mirasol treatment from 26 to 32 h post-WB collection, resulted in one breakthrough. These results highlight the importance of minimizing the time between WB collection and PI treatment.


Assuntos
Plaquetas/microbiologia , Segurança do Sangue , Klebsiella pneumoniae/efeitos dos fármacos , Klebsiella pneumoniae/efeitos da radiação , Fármacos Fotossensibilizantes/farmacologia , Riboflavina/farmacologia , Plaquetas/efeitos dos fármacos , Plaquetas/efeitos da radiação , Preservação de Sangue , Humanos , Infecções por Klebsiella/microbiologia , Infecções por Klebsiella/prevenção & controle , Klebsiella pneumoniae/crescimento & desenvolvimento , Projetos Piloto , Transfusão de Plaquetas , Raios Ultravioleta
8.
Small ; 17(12): e2100139, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33656273

RESUMO

The novel coronavirus SARS-CoV-2 has prompted a worldwide pandemic and poses a great threat to public safety and global economies. Most present personal protective equipment (PPE) used to intercept pathogenic microorganisms is deficient in biocidal properties. Herein, we present green nanofibers with effective antibacterial and antiviral activities that can provide sustainable bioprotection by continuously producing reactive oxygen species (ROS). The superiority of the design is that the nanofibers can absorb and store visible light energy and maintain the activity under light or dark environment. Moreover, the nanofibers can uninterruptedly release ROS in the absence of an external hydrogen donor, acting as a biocide under all weather conditions. A facile spraying method is proposed to rapidly deploy the functional nanofibers to existing PPE, such as protective suits and masks. The modified PPE exhibit stable ROS production, excellent capacity for storing activity potential, long-term durability, and high bactericidal (>99.9%) and viricidal (>99.999%) efficacies.


Assuntos
Anti-Infecciosos/farmacologia , Hidrogênio/química , Luz , Nanofibras/química , Benzofenonas/química , Celulose/farmacologia , Nanofibras/ultraestrutura , Riboflavina/farmacologia
9.
Methods Mol Biol ; 2280: 3-14, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33751425

RESUMO

Riboflavin (vitamin B2) is a vitamin of the B group involved in essential biological pathways, including redox reactions and the electron transport chain. Some lactic acid bacteria (LAB) can synthesize riboflavin and this capability is strain-dependent. In the last years, a growing interest has focused on the selection of riboflavin-overproducing food-grade LAB for the vitamin biofortification of fermented foods, as well as for the formulation of innovative functional products.In this chapter we report fast and inexpensive techniques in order to (1) screen LAB isolates able to produce riboflavin from different matrices, (2) select spontaneous roseoflavin-resistant riboflavin overproducing strains, and (3) quantify vitamin B2 in culture media by fluorescence detection.These protocols could be useful to select new overproducing strains and/or species from different ecological niches, as well as to optimize the conditions for vitamin bioproduction.


Assuntos
Lactobacillales/crescimento & desenvolvimento , Riboflavina/análogos & derivados , Riboflavina/análise , Técnicas Bacteriológicas , Meios de Cultura/química , Farmacorresistência Bacteriana , Alimentos e Bebidas Fermentados/microbiologia , Fluorescência , Lactobacillales/metabolismo , Riboflavina/farmacologia
10.
Exp Eye Res ; 205: 108484, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33548255

RESUMO

The purpose of the study was to determine the decrease in pachymetry of very thin corneas with advanced keratoconus due to corneal compaction from the ultraviolet-A (UV-A) irradiation phase of transepithelial (epi-on) cross-linking. Twenty removed corneal buttons were obtained from patients who underwent penetrating keratoplasty for advanced keratoconus. Removed corneal buttons selected from among the post-surgical specimens for this study had intact epithelium, no scarring or surgical cautery, endothelial cell density >2500 cells/mm2, and average pachymetry over the measured points of below 400 µm. Corneas were mounted in a Franz chamber. Each epithelial surface was soaked in isotonic riboflavin and D-alpha-tocopheryl polyethylene glycol 1000 succinate (Ribocross® IROMED Group, Italy) for 15 min. Pachymetry was measured at three points over both the shielded and unshielded corneal halves for each corneal button. Surfaces were then washed in saline to remove the Ribocross®. Shields from UV-A irradiation over half of each cornea were then fixed to stand 5 mm above the test corneas. UV-A irradiation using the custom fast cross-linking (CF-CXL) protocol was then performed for the typical 10 ± 1.5 min, for a total energy of 1.08 ± 0.6 J/cm2 after which pachymetry was re-measured. The average percent change in pachymetry was -0.43% ± 0.38% (maximum -1.06%) in the shielded half. Pachymetry change was -6.2% ± 2.2% (maximum 12%) in the cross-linked halves. In conclusion, we estimate that the change in corneal thickness from corneal compaction due to the cross-linking reaction itself was -5.8% ± 2.2%. Scanning electron microscopy of cross-linked corneal segments showed stromal fiber contraction.


Assuntos
Substância Própria/efeitos dos fármacos , Reagentes para Ligações Cruzadas , Ceratocone/tratamento farmacológico , Fármacos Fotossensibilizantes/farmacologia , Riboflavina/farmacologia , Vitaminas/farmacologia , alfa-Tocoferol/farmacologia , Paquimetria Corneana , Substância Própria/patologia , Substância Própria/ultraestrutura , Humanos , Ceratocone/patologia , Microscopia Eletrônica de Varredura , Tamanho do Órgão , Raios Ultravioleta
11.
Exp Eye Res ; 205: 108498, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33600810

RESUMO

Diffusion is an important mechanism of transport for nutrients and drugs throughout the avascular corneal stroma. The purpose of this study was to investigate the depth- and direction-dependent changes in stromal transport properties and their relationship to changes in collagen structure following ultraviolet A (UVA)-riboflavin induced corneal collagen cross-linking (CXL). After cross-linking in ex vivo porcine eyes, fluorescence recovery after photobleaching (FRAP) was performed to measure fluorescein diffusion in the nasal-temporal (NT) and anterior-posterior (AP) directions at corneal depths of 100, 200, and 300 µm. Second harmonic generation (SHG) imaging was also performed at these three corneal depths to quantify fiber alignment. For additional confirmation, an electrical conductivity method was employed to quantify ion permeability in the AP direction in corneal buttons and immunohistochemistry (IHC) was used to image collagen structure. Cross-linked corneas were compared to a control treatment that received the riboflavin solution without UVA light (SHAM). The results of FRAP revealed that fluorescein diffusivity decreased from 23.39 ± 11.60 µm2/s in the SHAM group to 19.87 ± 10.10 µm2/s in the CXL group. This change was dependent on depth and direction: the decrease was more pronounced in the 100 µm depth (P = 0.0005) and AP direction (P = 0.001) when compared to the effect in deeper locations and in the NT direction, respectively. Conductivity experiments confirmed a decrease in solute transport in the AP direction (P < 0.0001). FRAP also detected diffusional anisotropy in the porcine cornea: the fluorescein diffusivity in the NT direction was higher than the diffusivity in the AP direction. This anisotropy was increased following CXL treatment. Both SHG and IHC revealed a qualitative decrease in collagen crimping following CXL. Analysis of SHG images revealed an increase in coherency in the anterior 200 µm of CXL treated corneas when compared to SHAM treated corneas (P < 0.01). In conclusion, CXL results in a decrease in stromal solute transport, and this decrease is concentrated in the most anterior region and AP direction. Solute transport in the porcine cornea is anisotropic, and an increase in anisotropy with CXL may be explained by a decrease in collagen crimping.


Assuntos
Substância Própria/efeitos dos fármacos , Reagentes para Ligações Cruzadas , Fluoresceína/metabolismo , Fármacos Fotossensibilizantes/farmacologia , Riboflavina/farmacologia , Animais , Transporte Biológico Ativo/fisiologia , Colágeno Tipo I/metabolismo , Substância Própria/metabolismo , Condutividade Elétrica , Imuno-Histoquímica , Transporte de Íons/fisiologia , Masculino , Fotoquimioterapia , Sus scrofa , Raios Ultravioleta
12.
Transfusion ; 61(5): 1551-1561, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33629371

RESUMO

BACKGROUND: Accelerated development of the platelet (PLT) storage lesion upon pathogen inactivation (PI) is associated with the release of proteins from granules and platelet microvesicles (PMVs). Whether PI treatments alter the interaction between PLT factors and the vessel endothelium is of interest in understanding the risk profile of these technologies. STUDY DESIGN AND METHODS: In a pool-and-split study, one platelet concentrate (PC) was treated with riboflavin/UV (RF/UV) light, while the other one was kept as an untreated control. Releasates and PMV-depleted releasates were prepared by differential centrifugation steps on days 0, 1, 5, and 7 of storage. Cytokine/chemokine release following PI treatment was analyzed by an antibody array, and results were verified by the enzyme-linked immunosorbent assay. PMVs were enumerated by CD41 labeling and flow cytometry. Wound scratch assays were performed using cultured Ea.hy926 cells exposed to the differently prepared releasates. Effects of releasates on the phosphorylation levels of kinases ERK and p38 expressed by endothelial cells were analyzed by immunoblot. RESULTS: Cytokine/chemokine assays identified a 2-fold increase in epidermal growth factor released from PCs treated with RF/UV light compared with control. PMV count increased ~100-fold following PI treatment. Unmodified releasates and PMV-depleted releasates displayed different contributions to the kinetics of endothelial cell wound closure. This observation was associated with an increased ERK versus unaltered p38 activation in the endothelial cells. CONCLUSION: This study identified an inhibitory impact of PMVs on endothelial cell migration/proliferation upon stimulation by released cytokines and PMVs from PLTs treated with RF/UV light for endothelial cell wound closure.


Assuntos
Plaquetas/efeitos dos fármacos , Plaquetas/efeitos da radiação , Micropartículas Derivadas de Células/metabolismo , Citocinas/metabolismo , Células Endoteliais/citologia , Plaquetas/metabolismo , Preservação de Sangue , Segurança do Sangue , Linhagem Celular , Movimento Celular , Proliferação de Células , Células Endoteliais/metabolismo , Células Endoteliais da Veia Umbilical Humana , Humanos , Riboflavina/farmacologia , Esterilização , Raios Ultravioleta
13.
Int J Mol Sci ; 22(4)2021 Feb 06.
Artigo em Inglês | MEDLINE | ID: mdl-33561941

RESUMO

Gelatin methacryloyl (GelMA) is a versatile biomaterial that has been used in various biomedical fields. UV light is commonly used to photocrosslink such materials; however, its use has raised several biosafety concerns. We investigated the mechanical and biological properties of a visible-wavelength (VW)-light-crosslinked gelatin-based hydrogel to evaluate its viability as a scaffold for bone regeneration in bone-destructive disease treatment. Irgacure2959 or riboflavin was added as a photoinitiator to create GelMA solutions. GelMA solutions were poured into a mold and exposed to either UV or VW light. KUSA-A1 cell-laden GelMA hydrogels were crosslinked and then cultured. Mechanical characterization revealed that the stiffness range of GelMA-RF hydrogel was suitable for osteoblast differentiation. KUSA-A1 cells encapsulated in GelMA hydrogels photopolymerized with VW light displayed significantly higher cell viability than cells encapsulated in hydrogels photopolymerized with UV light. We also show that the expression of osteogenesis-related genes at a late stage of osteoblast differentiation in osteoblasts encapsulated in GelMA-RF hydrogel was markedly increased under osteoblast differentiation-inducing conditions. The GelMA-RF hydrogel served as an excellent scaffold for the encapsulation of osteoblasts. GelMA-RF hydrogel-encapsulated osteoblasts have the potential not only to help regenerate bone mass but also to treat complex bone defects associated with bone-destructive diseases such as periodontitis.


Assuntos
Regeneração Óssea/efeitos dos fármacos , Gelatina/farmacologia , Metacrilatos/farmacologia , Osteogênese/fisiologia , Propano/análogos & derivados , Engenharia Tecidual/métodos , Animais , Materiais Biocompatíveis/farmacologia , Diferenciação Celular/efeitos dos fármacos , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Luzes de Cura Dentária , Gelatina/química , Hidrogéis/farmacologia , Luz , Camundongos , Periodontite/terapia , Fotoiniciadores Dentários/farmacologia , Propano/farmacologia , Riboflavina/farmacologia , Tecidos Suporte/química
14.
Poult Sci ; 100(4): 100973, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33588345

RESUMO

In a companion study, we found that inclusion of different doses of riboflavin affected growth performance of Ross 708 male broilers' responses to coccidial challenge (by 5 Eimeria spp on day 14 of age) and dietary Bacillus subtilis (B. subtilis) supplementation. The current study was conducted to further test whether supplementation of B. subtilis and riboflavin will reduce negative impact and inflammation caused by Eimeria spp proliferation and help proper function of internal organs. A total of 1,248 Ross × Ross 708 male broiler chicks were randomly placed in 96 floor pens (8 blocks, 12 treatments). Treatments were arranged in a 3 (riboflavin) × 2 (B. subtilis) × 2 (Coccidial challenge) factorial arrangement in a randomized complete block design. Coccidial challenge reduced the weight of sampled birds on day 27 and day 36 and increased the relative weights of the internal organs of proventriculus, duodenum, jejunum, ileum, and spleen to BW on day 27, which may be because of inflammation caused by proliferation of Eimeria spp. The increased relative weights of duodenum, jejunum, ileum, and spleen on coccidial challenged birds were lost on day 36. Correlation analysis also indicated that the jejunum weight was positively related to villus height, Eimeria acervulina, and Eimeria maxima on day 27 but was not on day 36. The loss of the positive relationships may be because of recovery of the birds from coccidiosis on day 36. Even though the coccidial challenge and riboflavin interactively affected feed conversion ratio and BW gain and supplementation of dietary B. subtilis reduced mortality from day 35 to 42 in the companion study, the same response of internal organs was not observed in the current study. Coccidial challenge compromised development of internal organs of Ross 708 male broilers at an early age, but the negative effects subsided with age of birds rather than supplementation of riboflavin and B. subtilis at current tested levels under our experimental set up.


Assuntos
Coccidiose , Doenças das Aves Domésticas , Ração Animal/análise , Animais , Bacillus subtilis , Galinhas , Coccidiose/veterinária , Dieta/veterinária , Suplementos Nutricionais , Masculino , Doenças das Aves Domésticas/tratamento farmacológico , Riboflavina/farmacologia
15.
Graefes Arch Clin Exp Ophthalmol ; 259(5): 1225-1234, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33443628

RESUMO

PURPOSE: To analyze the effect of riboflavin UV-A illumination on mRNA and protein expression of healthy (HCFs) and keratoconus human corneal fibroblasts (KC-HCFs), concerning the inflammatory markers NF-κB, iNOS, IL-6, and collagen 1 and 5 (Col 1/Col 5). METHODS: Keratocytes were isolated from healthy (n = 3) and keratoconus (KC) corneas (n = 3) and were cultivated in basal medium with 5% fetal calf serum, which resulted in their transformation into human corneal fibroblasts (HCFs/KC-HCFs). Cells underwent 0.1% riboflavin UV-A illumination for 250 s (CXL). NF-κB, iNOS, IL-6, Col 1, and Col 5 expression was investigated by qPCR and Western blot analysis. IL-6 concentration of the cell culture supernatant and cell lysate was determined by ELISA. RESULTS: In untreated KC-HCFs, NF-κB (p = 0.0002), iNOS (p = 0.0019), Col 1 (p = 0.0286), and Col 5 (p = 0.0054) mRNA expression was higher and IL-6 expression was lower (p = 0.0057), than in healthy controls. In HCFs, CXL led to an increased NF-κB (p = 0.0286) and IL-6 (p = 0.0057) mRNA expression. The IL-6 concentration in the cell culture supernatant was increased in HCFs (p = 0.0485) and KC-HCFs (p = 0.0485) after CXL. CXL increased intracellular IL-6 concentration only in KC-HCFs (p = 0.0357). In the HCF group (p = 0.0286), an increased Col 1 mRNA expression after CXL could be observed. CONCLUSION: Our study confirmed altered gene expression in untreated KC-HCFs compared to untreated HCFs. Riboflavin UV-A illumination affected gene expression only in HCFs. Increased IL-6 concentration in the cell culture supernatant and cell lysate indicate a secondary inflammatory response of HCFs and KC-HCFs to riboflavin UV-A illumination.


Assuntos
Ceratocone , Fotoquimioterapia , Colágeno/uso terapêutico , Córnea , Reagentes para Ligações Cruzadas/uso terapêutico , Fibroblastos , Humanos , Interleucina-6/genética , Ceratocone/tratamento farmacológico , Iluminação , Fármacos Fotossensibilizantes/farmacologia , Fármacos Fotossensibilizantes/uso terapêutico , Riboflavina/farmacologia , Riboflavina/uso terapêutico , Raios Ultravioleta
16.
Int J Biol Macromol ; 172: 231-240, 2021 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-33453253

RESUMO

Photodynamic inactivation (PDI) is a novel sterilization technology that has proven effective in medicine. This study focused on applying PDI to food packaging, where chitosan (CS) films containing photosensitizing riboflavin (RB) were prepared via solution casting. The CS-RB composite films exhibited good ultraviolet (UV)-barrier properties, and had a visually appealing highly transparent yellow appearance. Scanning electron microscopy (SEM) confirmed even dispersion of RB throughout the CS film. The addition of RB led to improved film characteristics, including the thickness, mechanical properties, solubility, and water barrier properties. The CS-RB5 composite films produced sufficient singlet oxygen under blue LED irradiation for 2 h to inactivate two food-borne pathogens (Listeria monocytogenes and Vibrio parahaemolyticus) and one spoilage bacteria (Shewanella baltica). The CS-RB composite films were assessed as a salmon packaging material, where inhibition of bacterial growth was observed. The film is biodegradable, and has the potential to alleviate the issues associated with the excessive use of petrochemical materials, such as environmental pollution and limited resources. The CS-RB composite films showed potential as a novel environmentally friendly packaging material for shelf-life extension of refrigerated food products.


Assuntos
Antibacterianos/química , Quitosana/química , Embalagem de Alimentos/métodos , Química Verde , Fármacos Fotossensibilizantes/química , Riboflavina/química , Antibacterianos/farmacologia , Antibacterianos/efeitos da radiação , Humanos , Luz , Listeria monocytogenes/efeitos dos fármacos , Listeria monocytogenes/crescimento & desenvolvimento , Membranas Artificiais , Viabilidade Microbiana/efeitos dos fármacos , Fármacos Fotossensibilizantes/farmacologia , Fármacos Fotossensibilizantes/efeitos da radiação , Riboflavina/farmacologia , Riboflavina/efeitos da radiação , Shewanella/efeitos dos fármacos , Shewanella/crescimento & desenvolvimento , Oxigênio Singlete/agonistas , Oxigênio Singlete/química , Solubilidade , Vibrio parahaemolyticus/efeitos dos fármacos , Vibrio parahaemolyticus/crescimento & desenvolvimento , Água/química
17.
J Agric Food Chem ; 69(3): 945-954, 2021 Jan 27.
Artigo em Inglês | MEDLINE | ID: mdl-33438400

RESUMO

A novel chemical conjugate between chitosan (CH) and riboflavin (RF) has been synthesized and characterized via Fourier transform infrared, NMR, and other spectroscopic methods. Photophysical and photochemical properties such as absorption spectra, fluorescence emission, fluorescence anisotropy, and singlet oxygen generation were characterized as well. This new biopolymer-based conjugate was designed to have an antifungal effect enhanced through antimicrobial photodynamic therapy. The antifungal effect of this conjugate (CH-RF) was compared with CH and RF against Penicillium digitatum in vitro. The conjugate showed the highest fungal growth inhibition of all systems tested at a dose of 0.5% w/v. This new biopolymer-based compound could be a promising alternative to fungicides used in citrus fruits postharvest.


Assuntos
Quitosana/química , Quitosana/farmacologia , Fungicidas Industriais/farmacologia , Penicillium/efeitos dos fármacos , Riboflavina/química , Riboflavina/farmacologia , Citrus/microbiologia , Fungicidas Industriais/síntese química , Fungicidas Industriais/química , Luz , Penicillium/crescimento & desenvolvimento , Doenças das Plantas/microbiologia
18.
Exp Eye Res ; 202: 108355, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33171194

RESUMO

Over the past 20 years, corneal crosslinking (CXL) has been used by surgeons to halt progression in eyes with keratoconus. We reviewed the literature regarding the mechanism of action of CXL, the role of each of its components the strong biologic reaction, and their effects on cell interaction, proteins involved, wound healing, and cytotoxic reaction. CXL surgery involves a photochemical response in which ultraviolet light at a given wavelength and riboflavin participate. The combination of irradiation with UVA light and riboflavin leads to an intense process of apoptosis of keratocytes in the anterior stroma. Differences in light irradiation, as well as the importance of riboflavin and its vehicle, were also detailed. The surgery creates additional chemical bonds between the amino terminals of the collagen side chains and the proteoglycans of the extracellular matrix. A photosensitization reaction catalyzed by riboflavin classically involves the production of singlet oxygen. Microstructure studies show changes in the size of the fibril and potentially in the interfibrillar space, that the most significant changes related to the stiffening effect of CXL occur in the anterior third of the cornea and that short irradiation times, especially below 5 min, may not have the same biological effect. Changes in the riboflavin vehicle, with the incorporation of Hydroxypropyl methylcellulose as a carrier, can lead to faster diffusion and a more intense photochemical reaction. These are findings that can impact the optimal adjustment of irradiation time according to the riboflavin (and its carrier) used. Many studies have suggested that CXL is safe and effective in the standard and accelerated protocols that have been used by surgeons. After the initial depletion of anterior keratocytes, keratocyte density seems to return to average 6-12 months after surgery when corneas are examined with the confocal microscope.


Assuntos
Colágeno/farmacologia , Substância Própria/ultraestrutura , Reagentes para Ligações Cruzadas/farmacologia , Ceratocone/tratamento farmacológico , Fotoquimioterapia/métodos , Riboflavina/farmacologia , Humanos , Ceratocone/diagnóstico , Microscopia Confocal , Microscopia Eletrônica de Transmissão , Fármacos Fotossensibilizantes/farmacologia , Raios Ultravioleta
19.
Photodiagnosis Photodyn Ther ; 33: 102145, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33359161

RESUMO

PURPOSE: To assess the micro-tensile bond strength (µ-TBS), degree of conversion, and antimicrobial capacity of modified dentin adhesive using riboflavin photoinitiators. MATERIALS AND METHODS: Three groups of adhesives (control; 0.1 % riboflavin-PDT and 0.5 % riboflavin PDT) were prepared and tested on 70 sound molar teeth. Fourier-transformed infrared spectroscopy (FTIR) was performed for riboflavin and riboflavin-modified adhesives to calculate the degree of conversion. Contact angle measurement was performed by dropping a 5 µL droplet of the adhesives onto polished dentin disk. For µ-TBS testing, the dentin beams were fixed on a micro-tensile tester and were loaded in tension at a cross-head speed of 1 mm per min until fracture. The viability of Streptococcus mutans biofilm was tested using MTT assay. RESULTS: The spectrum at 1728 cm-1 indicates CO stretching frequency of riboflavin. The groups control and 0.1 % riboflavin PDT showed the highest degree of conversion followed by lowest degree of conversion of 0.5 % riboflavin adhesive after PDT. The control adhesive exhibited the highest contact angle over the dentin surface compared to the riboflavin-modified adhesive groups (p < 0.05). The lowest contact angle was observed for 0.1 % riboflavin that showed increased permeability of the adhesive onto the dentin surface (p < 0.05). The variables of immediate bonding (F = 12.328, p = 0.000) and ageing in artificial saliva (F = 41.559, p = 0.000) significantly affected the bond strength. For aged µ-TBS testing, the scores for 0.1 % riboflavin PDT was significantly higher as compared to the 0.5 % riboflavin PDT samples. The MTT resulted in a lower S. mutans viability for 0.5 % riboflavin PDT compared to 0.1 % riboflavin PDT and control adhesive (p < 0.05), irrespective of any time point, that is, after 24 h and 30 days ageing. CONCLUSIONS: The addition of riboflavin as photosensitizer in dentin adhesive demonstrated higher bond strength, excellent antimicrobial capability, and degree of conversion following PDT. The addition of riboflavin in dentin adhesive for PDT could be used as a potential restorative material in adhesive dentistry.


Assuntos
Adesivos Dentinários , Fotoquimioterapia , Adesivos , Resinas Compostas , Dentina , Adesivos Dentinários/farmacologia , Teste de Materiais , Fotoquimioterapia/métodos , Fármacos Fotossensibilizantes/farmacologia , Cimentos de Resina , Riboflavina/farmacologia
20.
Food Chem ; 335: 127576, 2021 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-32739805

RESUMO

The main causes of food spoilage come from the process of oxidation and the contamination by microorganisms. For the purpose of increasing food shelf-life the industries employ different techniques, being the addition of preservatives, one of the most used. The aim of this contribution was to investigate the potential antioxidant properties of tyrosol (4-hydroxyphenethyl alcohol, 4-OH) and tyrosol derived isomers (2-hydroxyphenethyl alcohol, 2-OH and 3-hydroxyphenethyl alcohol, 3-OH) against reactive oxygen species (ROS) and the antimicrobial effect on Staphylococcus aureus and Escherichia coli. Furthermore, the type of antioxidant effect of substrates and commercial antioxidants mixtures was studied. Upon visible-light, the substrates interacted with the vitamin B2 and different ROS were generated. All the compounds deactivated O2(1Δg) and O2●-, whereas only 2-OH and 3-OH inhibited H2O2 and HO●. The substrates exhibited a synergistic antioxidant effect when combined with commercial antioxidants. 2-OH showed antimicrobial activity against strains tested.


Assuntos
Aditivos Alimentares/farmacologia , Álcool Feniletílico/análogos & derivados , Riboflavina/farmacologia , Anti-Infecciosos/química , Anti-Infecciosos/farmacologia , Antioxidantes/química , Antioxidantes/farmacologia , Sinergismo Farmacológico , Peróxido de Hidrogênio/química , Radical Hidroxila/química , Álcool Feniletílico/química , Álcool Feniletílico/farmacologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...