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1.
Braz. J. Pharm. Sci. (Online) ; 58: e18719, 2022. tab, graf
Article in English | LILACS | ID: biblio-1364412

ABSTRACT

Abstract The aim of present study was calculate the Minimum inhibitory concentrations (MICs) of silver nanoparticles and clotrimazole for Candida species and their interaction by the adaptation of standarized methods. The MICs values of clotrimazole were 9 E-04-3 E-03 ug/ml, 0.1-0.6 ug/ml, 3 E-03- 0.1 ug/ml and 3 E-03-0.3 ug/ml for Candida albicans susceptible to fluconazole, Candida albicans resistance to fluconazole, Candida krusei and Candida parapsilosis respectively. The MICs values of silver nanoparticles were 26.50- 53 ug/ml; 26.50-106 ug/ml; 106-212 ug/ ml and 26.50- 53 ug/ml for Candida albicans susceptible to fluconazole, Candida albicans resistance to fluconazole, Candida krusei and Candida parapsilosis respectively. Synergism between clotrimazole and silver nanoparticles was measured by checkerboard BMD (broth microdilution) test and shown only for C. albicans susceptible to fluconazole because the fractional inhibitory concentrations (FICs) values were 0.07 - 0.15 ug/ml. Indifference was shown for the other species tested because the FICs values were between 0.5 - 2- 3.06 ug/ml. The results suggest synergistic activity depending on the fungus species analysed, however we recommend the incorporation of others measurement methodologies to confirm our results. As for measurement methodologies of MICs of silver nanoparticles and clotrimazole international normative were respected to guarantee reproducible and comparable results.


Subject(s)
Candida/classification , Clotrimazole/analogs & derivatives , Nanoparticles/administration & dosage , Antifungal Agents/adverse effects , Microbial Sensitivity Tests/instrumentation , Fungi
2.
Braz. J. Pharm. Sci. (Online) ; 58: e18800, 2022. tab, graf, ilus
Article in English | LILACS | ID: biblio-1364431

ABSTRACT

Abstract Efavirenz is one of the most commonly used drugs in HIV therapy. However the low water solubility tends to result in low bioavailability. Drug nanocrystals, should enhance the dissolution and consequently bioavailability. The aim of the present study was to obtain EFV nanocrystals prepared by an antisolvent technique and to further observe possible effect, on the resulting material, due to altering crystallization parameters. A solution containing EFV and a suitable solvent was added to an aqueous solution of particle stabilizers, under high shear agitation. Experimental conditions such as solvent/antisolvent ratio; drug load; solvent supersaturation; change of stabilizer; addition of milling step and solvents of different polarities were evaluated. Suspensions were characterized by particle size and zeta potential. After freeze- dried and the resulting powder was characterized by PXRD, infrared spectroscopy and SEM. Also dissolution profiles were obtained. Many alterations were not effective for enhancing EFV dissolution; some changes did not even produced nanosuspensions while other generated a different solid phase from the polymorph of raw material. Nevertheless reducing EFV load produced enhancement on dissolution profile. The most important modification was adding a milling step after precipitation. The resulting suspension was more uniform and the powder presented grater enhancement of dissolution efficacy.


Subject(s)
Efficacy/classification , HIV/pathogenicity , Crystallization/instrumentation , Dissolution/methods , Particle Size , Solubility , Pharmaceutical Preparations/administration & dosage , Excipients/pharmacology , Dissolution/classification , Nanoparticles/administration & dosage , Methods
3.
Electron. j. biotechnol ; 52: 21-29, July. 2021. ilus, tab, graf
Article in English | LILACS | ID: biblio-1283484

ABSTRACT

BACKGROUND: Super-paramagnetic iron oxide nanoparticles (SPION) contain a chemotherapeutic drug and are regarded as a promising technique for improving targeted delivery into cancer cells. RESULTS: In this study, the fabrication of 5-fluorouracil (5-FU) was investigated with loaded Dextran (DEXSPION) using the co-precipitation technique and conjugated by folate (FA). These nanoparticles (NPs) were employed as carriers and anticancer compounds against liver cancer cells in vitro. Structural, magnetic, morphological characterization, size, and drug loading activities of the obtained FA-DEX-5-FUSPION NPs were checked using FTIR, VSM, FESEM, TEM, DLS, and zeta potential techniques. The cellular toxicity effect of FA-DEX-5-FU-SPION NPs was evaluated using the MTT test on liver cancer (SNU-423) and healthy cells (LO2). Furthermore, the apoptosis measurement and the expression levels of NF-1, Her-2/neu, c-Raf-1, and Wnt-1 genes were evaluated post-treatment using flow cytometry and RT-PCR, respectively. The obtained NPs were spherical with a suitable dispersity without noticeable aggregation. The size of the NPs, polydispersity, and zeta were 74 ± 13 nm, 0.080 and 45 mV, respectively. The results of the encapsulation efficiency of the nano-compound showed highly colloidal stability and proper drug maintenance. The results indicated that FA-DEX-5-FU-SPION demonstrated a sustained release profile of 5-FU in both phosphate and citrate buffer solutions separately, with higher cytotoxicity against SNU-423 cells than against other cells types. These findings suggest that FA-DEX-SPION NPs exert synergistic effects for targeting intracellular delivery of 5-FU, apoptosis induction, and gene expression stimulation. CONCLUSIONS: The findings proved that FA-DEX-5-FU-SPION presented remarkable antitumor properties; no adverse subsequences were revealed against normal cells.


Subject(s)
Humans , Carcinoma, Hepatocellular/drug therapy , Fluorouracil/administration & dosage , Liver Neoplasms/drug therapy , Polymers , Gene Expression/drug effects , Drug Delivery Systems , Apoptosis/drug effects , Reverse Transcriptase Polymerase Chain Reaction , Delayed-Action Preparations , Nanoparticles/administration & dosage , Magnetite Nanoparticles , Flow Cytometry
4.
Braz. arch. biol. technol ; 63: e20190427, 2020. tab, graf
Article in English | LILACS | ID: biblio-1132174

ABSTRACT

Abstract Acne Vulgaris is a common skin disease caused by Propionibacterium acnes, an anaerobic microbiota of human skin that plays a vital role in the pathology of acne. The aim of this study was to prepare nanoparticles containing an acne recombinant protein and determine its ability as an oral acne vaccine in mice. The recombinant Sialidase-CAMP gene was expressed and purified in a prokaryotic host. The chitosan nanoparticles containing the recombinant protein were prepared, encapsulated, and administered by both oral and subcutaneous routes to Balb/c mice. Sera IgA and IgG and stool IgA titers were measured by ELISA, and the immunized mice were challenged against P. acnes. A 65 kDa recombinant protein was confirmed by SDS-PAGE and western blot. The size and zeta potential of nanoparticles were 80 nm and +18 mV, respectively. After oral immunization, the serum IgG and IgA titers were 1:3200 and 1:16, respectively, and the stool IgA titer was 1:8. In the subcutaneous route, the serum IgG titer was 1:51200. Immunized mice showed no inflammation in the ear of challenged mice. It is the first study that examines a chitosan-nanoparticulated acne fusion protein as an applicable acne vaccine candidate with appropriate immunogenicity potential. Further studies are required to validate the clinical usefulness of this vaccine candidate.


Subject(s)
Animals , Female , Mice , Propionibacterium acnes/drug effects , Acne Vulgaris/prevention & control , Chitosan/administration & dosage , Nanoparticles/administration & dosage , Recombinant Proteins , Enzyme-Linked Immunosorbent Assay , Blotting, Western , Immunization/methods , Disease Models, Animal , Electrophoresis, Polyacrylamide Gel , Mice, Inbred BALB C , Neuraminidase
5.
Electron. j. biotechnol ; 32: 13-18, Mar. 2018. ilus, graf
Article in English | LILACS | ID: biblio-1022495

ABSTRACT

Background: The suppression of cancer cell growth and invasion has become a challenging clinical issue. In this study, we used nanotechnology to create a new drug delivery system to enhance the efficacy of existing drugs. We developed layered double hydroxide by combing Au nanosol (LDH@Au) and characterized the compound to prove its function as a drug delivery agent. The anti-cancer drug Doxorubicin was loaded into the new drug carrier to assess its quality. We used a combination of apoptosis assays, cell cycle assays, tissue distribution studies, cell endocytosis, transwell invasion assays, and immunoblotting to evaluate the characteristics of LDH@Au as a drug delivery system. Results: Our results show that the LDH@Au-Dox treatment significantly increased cancer cell apoptosis and inhibited cell invasion compared to the control Dox group. Additionally, our data indicate that LDH@Au-Dox has a better target efficiency at the tumor site and improved the following: cellular uptake, anti-angiogenesis action, changes in the cell cycle, and increased caspase pathway activation. Conclusions: Our findings suggest the nano drug is a promising anti-cancer agent and has potential clinical applications.


Subject(s)
Stomach Neoplasms/drug therapy , Doxorubicin/administration & dosage , Apoptosis/drug effects , Nanoparticles/administration & dosage , Antibiotics, Antineoplastic/administration & dosage , Doxorubicin/pharmacology , Cell Cycle/drug effects , Blotting, Western , Drug Delivery Systems , Nanotechnology , Cell Line, Tumor , Microscopy, Electron, Transmission , Cell Proliferation/drug effects , Endocytosis/drug effects , Hydroxides , Antibiotics, Antineoplastic/pharmacology , Neoplasm Invasiveness/prevention & control
6.
Rev. Assoc. Med. Bras. (1992) ; 64(1): 22-31, Jan. 2018. tab, graf
Article in English | LILACS | ID: biblio-896419

ABSTRACT

Summary Objective: Ovarian torsion must be diagnosed and treated as early as possible. The aim of the present study was to investigate the effects of intraperitoneal administration of nanocurcumin on ischemia-reperfusion injury in ovaries. Method: Thirty-five (35) healthy female Wistar rats weighing approximately 250 g were randomized into seven experimental groups (n=5): Group SSG - The rats underwent only laparotomy. Group I: A 3-hour ischemia only. Group I/R: A 3-hour ischemia and 3-hour reperfusion. Group I/C: A 3-hour ischemia only, and 1 mg/kg intraperitoneal administration of curcumin 2.5 hours after induction of ischemia. Group I/R/C: A 3-hour ischemia, 3-hour reperfusion, and 1 mg/kg intraperitoneal administration of curcumin 2.5 hours after induction of ischemia. Group I/NC: A 3-hour ischemia only and 1 mg/kg intraperitoneal administration of nanocurcumin 2.5 hours after induction of ischemia. Group I/R/C: A 3-hour ischemia, 3-hour reperfusion and 1 mg/kg intraperitoneal administration of nanocurcumin 2.5 hours after induction of ischemia. Results: Nanocurcumin-treated animals showed significantly improved development of ischemia and reperfusion tissue injury compared to those in the other groups (p<0.05). Significant higher values of SOD, tGSH, GPO, GSHRd and GST were observed in I/R/NC animals compared to those in the other groups (p<0.05). The damage indicators (NOS, MDA, MPO and DNA damage level) were significantly lower in I/R/NC animal compared to those of other groups (p<0.05). Conclusion: Intraperitoneal administration of nanocurcumin can be helpful in minimizing ischemia-reperfusion injury in ovarian tissue exposed to ischemia.


Subject(s)
Humans , Animals , Female , Rats , Ovary/blood supply , Reperfusion Injury/drug therapy , Curcumin/administration & dosage , Nanoparticles/administration & dosage , Ischemia/drug therapy , Antioxidants/administration & dosage , Administration, Cutaneous , Reperfusion Injury/pathology , Rats, Wistar , Disease Models, Animal , Injections, Intraperitoneal , Ischemia/pathology
7.
Braz. j. med. biol. res ; 51(3): 7090, 2018. tab, graf
Article in English | LILACS | ID: biblio-889042

ABSTRACT

Particles are usually polydispersed and size is an important feature for lipid-based drug delivery systems in order to optimize cell-particle interactions as to pharmacologic action and toxicity. Lipid nanoparticles (LDE) with composition similar to that of low-density lipoprotein carrying paclitaxel were shown to markedly reduce atherosclerosis lesions induced in rabbits by cholesterol feeding. The aim of this study was to test whether two LDE fractions, one with small (20-60 nm) and the other with large (60-100 nm) particles, had different actions on the atherosclerotic lesions. The two LDE-paclitaxel fractions, prepared by microfluidization, were separated by density gradient ultracentrifugation and injected (4 mg/body weight, intravenously once a week) into two groups of rabbits previously fed cholesterol for 4 weeks. A group of cholesterol-fed animals injected with saline solution was used as control to assess lesion reduction with treatment. After the treatment period, the animals were euthanized for analysis. After treatment, both the small and large nanoparticle preparations of LDE-paclitaxel had equally strong anti-atherosclerosis action. Both reduced lesion extension in the aorta by roughly 50%, decreased the intima width by 75% and the macrophage presence in the intima by 50%. The two preparations also showed similar toxicity profile. In conclusion, within the 20-100 nm range, size is apparently not an important feature regarding the LDE nanoparticle system and perhaps other solid lipid-based systems.


Subject(s)
Animals , Male , Rabbits , Paclitaxel/administration & dosage , Atherosclerosis/drug therapy , Tubulin Modulators/administration & dosage , Nanoparticles/administration & dosage , Lipids/administration & dosage , Lipoproteins, LDL/drug effects , Particle Size , Drug Therapy, Combination
8.
Acta cir. bras ; 32(1): 22-27, Jan. 2017. graf
Article in English | LILACS | ID: biblio-837669

ABSTRACT

Abstract Purpose: To assess the effectiveness of heparin, platelet-rich plasma (PRP), and silver nanoparticles on prevention of postoperative adhesion in animal models. Methods: Sixty males Albino Wistar rats aged 5 to 6 weeks were classified into five groups receiving none, heparin, PRP, silver nanoparticles, PRP plus silver nanoparticles intraperitoneally. After 2 weeks, the animals underwent laparotomy and the damaged site was assessed for peritoneal adhesions severity. Results: The mean severity scores were 2.5 ± 0.9, 2.16 ± 0.7, 1.5 ± 0.5, 2.66 ± 0.88, and 2.25 ± 0.62 in the control, heparin, PRP, silver and PRP plus silver groups, respectively with significant intergroup difference (p = 0.004). The highest effective material for preventing adhesion formation was PRP followed by heparin and PRP plus silver. Moreover, compared to the controls, only use of PRP was significantly effective, in terms of adhesion severity (p = 0.01) . Conclusion: Platelet-rich plasma alone may have the highest efficacy for preventing postoperative peritoneal adhesions in comparison with heparin, silver nanoparticles and PRP plus silver nanoparticles.


Subject(s)
Animals , Male , Rats , Peritoneal Diseases/prevention & control , Postoperative Complications/prevention & control , Silver/administration & dosage , Heparin/administration & dosage , Tissue Adhesions/prevention & control , Platelet-Rich Plasma , Nanoparticles/administration & dosage , Metal Nanoparticles/administration & dosage , Severity of Illness Index , Rats, Wistar , Laparotomy
9.
Braz. j. med. biol. res ; 50(10): e6225, 2017. tab, graf
Article in English | LILACS | ID: biblio-888940

ABSTRACT

Coronary allograft vasculopathy is an inflammatory-proliferative process that compromises the long-term success of heart transplantation and has no effective treatment. A lipid nanoemulsion (LDE) can carry chemotherapeutic agents in the circulation and concentrates them in the heart graft. The aim of the study was to investigate the effects of methotrexate (MTX) associated to LDE. Rabbits fed a 0.5% cholesterol diet and submitted to heterotopic heart transplantation were treated with cyclosporine A (10 mg·kg-1·day-1 orally) and allocated to treatment with intravenous LDE-MTX (4 mg/kg, weekly, n=10) or with weekly intravenous saline solution (control group, n=10), beginning on the day of surgery. Animals were euthanized 6 weeks later. Compared to controls, grafts of LDE-MTX treated rabbits showed 20% reduction of coronary stenosis, with a four-fold increase in vessel lumen and 80% reduction of macrophage staining in grafts. Necrosis was attenuated by LDE-MTX. Native hearts of both LDE-MTX and Control groups were apparently normal. Gene expression of lipoprotein receptors was significantly greater in grafts compared to native hearts. In LDE-MTX group, gene expression of the pro-inflammatory factors tumor necrosis factor-α, monocyte chemoattractant protein-1, interleukin-18, vascular cell adhesion molecule-1, and matrix metalloproteinase-12 was strongly diminished whereas expression of anti-inflammatory interleukin-10 increased. LDE-MTX promoted improvement of the cardiac allograft vasculopathy and diminished inflammation in heart grafts.


Subject(s)
Animals , Rabbits , Graft Rejection/prevention & control , Heart Transplantation/adverse effects , Immunosuppressive Agents/administration & dosage , Lipids/administration & dosage , Methotrexate/administration & dosage , Nanoparticles/administration & dosage , Allografts , Immunosuppressive Agents/pharmacology , Methotrexate/pharmacology , Nanoparticles/chemistry
10.
Indian J Exp Biol ; 2013 Dec; 51(12): 1055-1062
Article in English | IMSEAR | ID: sea-150292

ABSTRACT

yielded an average particle size of 120 nm with 70% encapsulation-efficiency. In vitro release profile of NP-OP showed sustained release of OP for 21 days. In vivo anti-fertility studies were conducted in marmosets. Results indicated that control animals conceived in the same cycle while two of three treated animals failed to conceive in treatment cycle. The in vivo studies thus corroborate with in vitro release of OP, demonstrating its anti-fertility activity in 66% of animals.


Subject(s)
Animals , Callithrix/physiology , Carrier Proteins/administration & dosage , Carrier Proteins/chemistry , Contraception , Female , Humans , Nanoparticles/administration & dosage , Nanoparticles/chemistry , Ovarian Follicle/chemistry , Particle Size , Peptide Fragments/administration & dosage , Peptide Fragments/chemistry , Polymers/administration & dosage , Polymers/chemistry
11.
Biol. Res ; 46(4): 407-419, 2013.
Article in English | LILACS | ID: lil-700403

ABSTRACT

Aquaculture has become an important economic sector worldwide, but is faced with an ongoing threat from infectious diseases. Vaccination plays a critical role in protecting commercially raised fish from bacterial, viral and parasitic diseases. However, the production of effective vaccines is limited by the scarcity of knowledge about the immune system of fish. Improving vaccines implies using antigens, adjuvants and employing methods of administration that are more effective and less harmful to the fish. In this context, in recent year there have studies of methods of encapsulating antigens in matrices of different types to apply in fish vaccines. This work reviews the new methods to improve fish vaccines by encapsulating them in polymers and polysaccharides.


Subject(s)
Animals , Antigens/administration & dosage , Fish Diseases/prevention & control , Polymers/administration & dosage , Polysaccharides/administration & dosage , Vaccines/administration & dosage , Antigens/immunology , Aquaculture , Biotechnology , Fish Diseases/immunology , Nanoparticles/administration & dosage
12.
Caracas; s.n; oct. 2012. ^c30 cmilus, tab, graf.
Thesis in Spanish | LIVECS, LILACS | ID: biblio-1150986

ABSTRACT

La inyección intravítrea ha sido la vía de administración más eficaz para el tratamiento de enfermedades vitreorretinianas. Su práctica continua, no es agradable para los pacientes y a su vez podría causar complicaciones indeseadas. El presente trabajo tuvo como objetivo desarrollar un nanosistema de liberación polímero-terapéutico (conjugado)/nanopartícula, utilizando Dextrano y Quitosano como polímeros transportadores biodegradables, hidrosolubles y compatibles a nivel ocular así como Hemisuccinato de Metilprednisolona como fármaco modelo. Primeramente, el fármaco fue capaz de unirse covalentemente a dos Dextranos de pesos moleculares 10 y 70 kDa. En función del contenido del componente activo y perfil de liberación, se seleccionó el Hemisuccinato de Metilprednisolona-Dextrano 10 kDa para elaborar las nanopartículas de Quitosano por el método de gelificación iónica empleando tripolifosfato sódico como agente entrecruzante. Por último, las nanopartículas fueron cubiertas con lactosa aplicando el secado por atomización. Se evaluó morfología, distribución de tamaño de las partículas, carga superficial, contenido y eficacia de captura del fármaco. Las partículas esféricas presentaron superficies lisas y uniformes. El pH tuvo influencia en el tamaño de las partículas observándose una distribución bimodal a pHs ≈ pKa del Quitosano y unimodal con un rango entre 130 - 170 nm a pHs < pKa. La variación de los potenciales Zeta entre los compuestos involucrados en la reacción, indicaron la posible ocurrencia de la misma. Al comparar la liberación del conjugado con las Nanopartículas a pH fisiológico, se observó que la encapsulación retrasó la liberación del fármaco alrededor de un 50%. Las nanopartículas recubiertas formaron micropartículas de 1.780 ± 0,5 nm, lo que favoreció su dispersibilidad en agua. Este nuevo nanosistema, evidenció su posible potencial en el desarrollo de formulaciones de liberación intravítrea, que reduzca la frecuencia de administración, ofreciendo una excelente alternativa que proporcione un mayor grado de satisfacción y mejore la calidad de vida del paciente.


Subject(s)
Humans , Retinal Diseases/drug therapy , Nanotechnology/organization & administration , Drug Liberation/drug effects , Polymers/pharmacology , Quality of Life , Retinal Diseases/complications , Methylprednisolone/therapeutic use , Chromatography, Liquid/methods , Dextrans/therapeutic use , Epiretinal Membrane/drug therapy , Delayed-Action Preparations/pharmacology , Chitosan/therapeutic use , Drug Compounding/methods , Particulate Matter/therapeutic use , Nanoparticles/administration & dosage , Intravitreal Injections/adverse effects
13.
Int. j. morphol ; 29(2): 403-408, June 2011. ilus
Article in English | LILACS | ID: lil-597465

ABSTRACT

The administration of microencapsulated drug in a matrix acid poly(lactic-co-glycolic acid) (PLGA) by intramuscular (IM) in humans has been approved by the FDA for various applications though it is not clear what effect they have on the morphological parameters of muscle tissue. The aim of this study was to analyze the morphological changes in the skeletal muscle tissue with their use. We used 12 adult female Sprague Dawley rats (Rattus novergicus) that were injected into their right gastrocnemius muscle belly with: sterile vehicle solution (G1, n = 4), 0.5 mg PLGA microparticle (G2, n = 4) and 0.75 mg PLGA microparticle (G3, n = 4), both dissolved in a sterile vehicle solution. At 14 days post injection the number and diameter of muscle fibers, the level of inflammation and histology appearance in terms of organization of muscle fibers, cellular distribution, tissue morphology and the presence of polymer waste were determined and the results between the groups compared. The administration of the compound in a single dose did not alter the morphometric parameters (number and diameter of muscle fibers) despite generating a mild inflammation in the tissue associated with the presence of polymeric residues, suggesting that the PLGA microparticles were well tolerated by the muscle tissue at concentrations tested (0.5 and 0.75 mg).


La administración de fármacos encapsulados en micropartículas de ácido poli-láctico/glicólico (PLGA) por vía intramuscular (IM) ha sido aprobada por FDA para su uso en seres humanos con variadas aplicaciones, no estando claro el efecto que tienen sobre los parámetros morfológicos del tejido muscular. El objetivo de este estudio fue analizar los cambios morfológicos en el tejido muscular esquelético. Se utilizaron 12 ratas (Rattus novergicus) hembras de la cepa Sprague Dawley, las cuales fueron inyectadas en el vientre del músculo gastrocnemio derecho con: solución vehículo estéril (G1, n=4) y con micropartículas 0,5 mg (G2, n=4) y 0,75 mg de PLGA (G3, n=4) ambas disueltas en solución vehículo estéril. A los 14 días post inyección se determinó el número y diámetro de fibras musculares, el nivel de inflamación y el aspecto histológico en términos de organización de fibras musculares, así como la distribución y morfología celular del tejido conjuntivo y presencia de residuos poliméricos, comparándose los resultados entre los grupos de estudio. La administración del compuesto en una sola dosis no modificó los parámetros morfométricos (número y diámetro de las fibras musculares), a pesar de generar una inflamación leve en el tejido, asociado a la presencia de residuos poliméricos, lo que sugiere que microesferas de PLGA son bien toleradas por el tejido muscular en las concentraciones probadas (0,5 and 0,75 mg).


Subject(s)
Animals , Female , Rats , Muscle, Skeletal/drug effects , Nanoparticles/administration & dosage , Polylactic Acid-Polyglycolic Acid Copolymer/administration & dosage , Polyglycolic Acid/administration & dosage , Drug Delivery Systems , Rats, Sprague-Dawley , Lactic Acid , Injections
14.
Int. j. morphol ; 28(4): 1263-1271, dic. 2010. ilus
Article in English | LILACS | ID: lil-582921

ABSTRACT

Engineered nanoparticles are designed to perform specific functions and therefore have specific properties that could potentially be harmful. Nanoparticles such as titanium dioxide have the potential to become transparent and are therefore widely used in cosmetic products and sunscreen. Research on the toxicity of nanoparticles is of utmost importance and numerous in vitro studies have shown that some of these particles could have adverse health effects. The current study aimed to investigate the in vivo effects of two different titanium nanoparticles at two different concentrations after inhalation by experimental BALB/c mice. This was done to determine whether these particles will cause an inflammatory reaction, visible as alterations in platelet and fibrin ultrastructure. Mice were divided into five experimental groups comprising of a control group, high and low concentration groups exposed to the spherical-shaped particles, as well as high and low concentration groups exposed to the rod-shaped particles. The ultrastructure of the fibrin networks and platelet aggregates of these experimental groups were investigated and compared to that of controls. Results indicated that the fibrin networks of the exposed animals have a net-like covering over the major fibres, typical to that found in animals with inflammation. It can therefore be concluded that the nanoparticles used in this study may have the potential to cause an inflammatory reaction, affecting the haemostatic physiology.


Las nanopartículas han sido diseñadas para realizar funciones específicas, y por lo tanto, tienen propiedades específicas que podrían ser perjudiciales. Las nanopartículas, como el dióxido de titanio tienen el potencial de llegar a ser transparentes, pudiendo ser ampliamente utilizadas en productos cosméticos y protectores solares. La investigación sobre la toxicidad de las nanopartículas es de suma importancia y numerosos estudios in vitro han demostrado que algunas de estas partículas, podrían tener efectos adversos para la salud. El presente estudio tuvo como objetivo investigar los efectos in vivo de dos nanopartículas de titanio diferentes en dos concentraciones después de la inhalación experimental de ratones BALB/c. Esto se realizó para determinar si las partículas provocan una reacción inflamatoria, visible como alteraciones en la ultraestructura de plaquetas y fibrina. Los ratones se dividieron en cinco grupos experimentales, que comprende un grupo control y grupos expuestos a nanopartículas de forma esférica de alta y baja concentración, así como grupos expuestos a nanopartículas en forma de barra de alta y baja concentración. Fueron investigadas la ultraestructura de las redes de fibrina y agregados plaquetarios de estos grupos experimentales y se comparó con la de los controles. Los resultados indicaron que en los animales expuestos se observó una red de fibrina que recubría las fibras más grandes, típicas de las que se encuentran en los animales con inflamación. Por lo tanto, puede concluirse que las nanopartículas utilizadas en este estudio pueden tener el potencial de causar una reacción inflamatoria, afectando a la fisiología hemostática.


Subject(s)
Animals , Mice , Fibrin/ultrastructure , Nanoparticles/toxicity , Blood Platelets/ultrastructure , Titanium/toxicity , Disease Models, Animal , Fibrin , Inhalation Exposure , Mice, Inbred BALB C , Nanoparticles/administration & dosage , Blood Platelets , Toxicity Tests , Titanium/administration & dosage
15.
Clinics ; 65(1): 23-27, 2010. tab, graf
Article in English | LILACS | ID: lil-538603

ABSTRACT

Introduction: Obesity increases triglyceride levels and decreases high-density lipoprotein concentrations in plasma. Artificial emulsions resembling lipidic plasma lipoprotein structures have been used to evaluate low-density lipoprotein metabolism. In grade III obesity, low density lipoprotein metabolism is poorly understood. Objective: To evaluate the kinetics with which a cholesterol-rich emulsion (called a low-density emulsion) binds to low-density lipoprotein receptors in a group of patients with grade III obesity by the fractional clearance rate. Methods: A low-density emulsion was labeled with [14C]-cholesterol ester and [³H]-triglycerides and injected intravenously into ten normolipidemic non-diabetic patients with grade III obesity [body mass index higher than 40 kg/m²] and into ten non-obese healthy controls. Blood samples were collected over 24 hours to determine the plasma decay curve and to calculate the fractional clearance rate. Results: There was no difference regarding plasma levels of total cholesterol or low-density lipoprotein cholesterol between the two groups. The fractional clearance rate of triglycerides was 0.086 ± 0.044 in the obese group and 0.122 ± 0.026 in the controls (p = 0.040), and the fractional clearance rate of cholesterol ester (h-1) was 0.052 ± 0.021 in the obese subjects and 0.058 ± 0.015 (p = 0.971) in the controls. Conclusion: Grade III obese subjects exhibited normal low-density lipoprotein removal from plasma as tested by the nanoemulsion method, but triglyceride removal was slower.


Subject(s)
Adult , Female , Humans , Male , Middle Aged , Cholesterol, LDL/pharmacokinetics , Fat Emulsions, Intravenous/pharmacokinetics , Nanoparticles , Obesity/blood , Case-Control Studies , Fat Emulsions, Intravenous/administration & dosage , Fat Emulsions, Intravenous/chemistry , Nanoparticles/administration & dosage
16.
Arq. bras. endocrinol. metab ; 53(1): 95-101, fev. 2009. tab
Article in Portuguese | LILACS | ID: lil-509871

ABSTRACT

INTRODUÇÃO: Os portadores de diabetes melito tipo 1 (DM1) possuem aumentado risco de doença cardiovascular e, ainda assim, podem apresentar perfil lipídico normal. Para esclarecer se os níveis normais de HDL podem ocultar defeitos na função, foram estudados a transferência de lípides para a HDL em DM1. MÉTODOS: Vinte e uma mulheres jovens portadoras de DM1 foram comparadas com 21 mulheres não-diabéticas. Nanoemulsões foram usadas como doadoras de lípides para HDL: uma marcada com ³H-triglicérides e 14C-colesterol livre e outra com ³H-éster de colesterol e 14C-fosfolípides. Após 1 hora de incubação com amostras de plasma, seguida por precipitação química, o sobrenadante, contendo HDL, teve a radioatividade contada. RESULTADOS: Nenhuma diferença foi encontrada nas transferências dos ésteres de colesterol, triglicérides, colesterol livre e fosfolípides para as HDL. CONCLUSÃO: A transferência de lípides para a HDL não está afetada em portadoras de DM1. Isso sugere que a doença não altera a composição de lipoproteínas e a ação de proteínas de transferência.


INTRODUCTION: People with type 1 diabetes mellitus (T1DM) have an increased risk of cardiovascular disease and may still have a normal lipid profile. In order to clarify whether normal HDL cholesterol levels may conceal defects in HDL function, we have studied the transfer of lipids to HDL in T1DM. METHODS: Twenty-one young women with T1DM were compared with 21 non-diabetic women. Nanoemulsion preparations were used as lipid donor to HDL: one labeled with ³H-triglycerides and 14C-free cholesterol and the other with ³H-cholesteryl esters and 14C-phospholipids. These preparations were incubated with plasma samples for 1h. After chemical precipitation, the supernatant containing HDL was counted for radioactivity. RESULTS: No difference in transfer was observed to nanoemulsion HDL from cholesteryl esters, triglycerides, free cholesterol and phospholipids. CONCLUSION: Simultaneous lipid transfer to HDL was not affected in T1DM patients. This suggests that the disease does not alter lipoprotein composition and transfer protein action in such way as to disturb HDL metabolism.


Subject(s)
Adult , Female , Humans , Young Adult , Carrier Proteins/metabolism , Diabetes Mellitus, Type 1/metabolism , Lipids/administration & dosage , Lipoproteins, HDL/ultrastructure , Nanoparticles/administration & dosage , Biological Transport/physiology , Case-Control Studies , Cholesterol Esters/administration & dosage , Cholesterol Esters/blood , Cholesterol Esters/pharmacokinetics , Lipids/blood , Lipids/pharmacokinetics , Lipoproteins, HDL/chemistry , Lipoproteins, HDL/metabolism , Phospholipids/administration & dosage , Phospholipids/blood , Phospholipids/pharmacokinetics , Statistics, Nonparametric , Triglycerides/administration & dosage , Triglycerides/blood , Triglycerides/pharmacokinetics , Young Adult
17.
Journal of Veterinary Science ; : 321-326, 2006.
Article in English | WPRIM | ID: wpr-197261

ABSTRACT

Biocompatible silica-overcoated magnetic nanoparticles containing an organic fluorescence dye, rhodamine B isothiocyanate (RITC), within a silica shell [50 nm size, MNP@SiO2(RITC)s] were synthesized. For future application of the MNP@SiO2(RITC)s into diverse areas of research such as drug or gene delivery, bioimaging, and biosensors, detailed information of the cellular uptake process of the nanoparticles is essential. Thus, this study was performed to elucidate the precise mechanism by which the lung cancer cells uptake the magnetic nanoparticles. Lung cells were chosen for this study because inhalation is the most likely route of exposure and lung cancer cells were also found to uptake magnetic nanoparticles rapidly in preliminary experiments. The lung cells were pretreated with different metabolic inhibitors. Our results revealed that low temperature disturbed the uptake of magnetic nanoparticles into the cells. Metabolic inhibitors also prevented the delivery of the materials into cells. Use of TEM clearly demonstrated that uptake of the nanoparticles was mediated through endosomes. Taken together, our results demonstrate that magnetic nanoparticles can be internalized into the cells through an energy-dependent endosomal-lysosomal mechanism.


Subject(s)
Humans , Biocompatible Materials/pharmacokinetics , Cell Line, Tumor , Drug Delivery Systems/methods , Endocytosis/physiology , Endosomes/physiology , Lung Neoplasms/drug therapy , Macrolides/pharmacology , Microscopy, Confocal , Microscopy, Electron, Transmission , Nanoparticles/administration & dosage , Sodium Azide/pharmacology , Sucrose/pharmacology , Temperature
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