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1.
BMC Ophthalmol ; 23(1): 471, 2023 Nov 20.
Artículo en Inglés | MEDLINE | ID: mdl-37985976

RESUMEN

BACKGROUND: Transepithelial corneal crosslinking (CXL) is a novel surgical approach for the treatment of keratoconus, which is a bilateral asymmetrical ophthalmological disease accompanied by progressive corneal ectasia. Silicon hydrogel (SiH) contact lenses have been extensively used in clinical ophthalmologic medicine, as a postoperative ophthalmological intervention. However, the ideal lens application duration after transepithelial CXL remains uncertain. Here, we aimed to investigate the effects and comfort of immediate corneal contact lens use after transepithelial CXL for keratoconus. METHODS: In this prospective study, 60 patients with keratoconus who underwent transepithelial CXL treatment were enrolled from September 2021 to January 2023 with a male:female ratio of 39:21, and an average age of 25.42 ± 5.47 years. The patients were divided randomly into two groups: group A contained 30 patients wearing silicone hydrogel contact lenses for 7 days postoperatively, and group B contained 30 patients wearing the same contact lenses for 3 days. Ten subjective ophthalmologic symptoms were surveyed by the patients, including pain, photophobia, foreign body sensation, tearing, burning, blurred vision, dry eyes, difficulty opening the eyes, astringency, and stinging. Ophthalmologic signs, including corneal edema and conjunctival congestion, were recorded by a single clinician on postoperative days 1, 3, and 7. RESULTS: Each surgical procedure was readily performed without complications, and both groups postoperative day 7 (P = 0.04), where group B scored (0.01 ± 0.41) lesser than group A (0.12 ± 0.29), whilst corneal edema in both groups recorded significantly different on postoperative days 5 and 7 (group A demonstrated the result of 0.17 ± 0.14 and 0.08 ± 0.11 for the respective days, whereas group B indicated 0.10 ± 0.13 and 0.03 ± 0.07 at the corresponding times). CONCLUSIONS: Immediate use of silicone hydrogel corneal lenses after transepithelial CXL effectively alleviates postoperative ocular distress, particularly with a three-day use period as the ideal duration.


Asunto(s)
Lentes de Contacto , Edema Corneal , Queratocono , Humanos , Masculino , Femenino , Adulto Joven , Adulto , Queratocono/tratamiento farmacológico , Queratocono/diagnóstico , Silicio/uso terapéutico , Estudios Prospectivos , Reticulación Corneal , Hidrogeles/uso terapéutico , Córnea , Siliconas/uso terapéutico , Reactivos de Enlaces Cruzados/uso terapéutico , Fármacos Fotosensibilizantes/uso terapéutico , Riboflavina/uso terapéutico , Rayos Ultravioleta , Topografía de la Córnea
2.
Biochem Biophys Res Commun ; 533(4): 698-703, 2020 12 17.
Artículo en Inglés | MEDLINE | ID: mdl-33131768

RESUMEN

Chronic renal failure is exacerbated by oxidative stress, and this condition is difficult to treat in advanced stages. Because of the lack of effective treatments, the disease is a global public health concern. We developed a Si-based agent that continuously generates hydrogen for more than 24 h by reacting with water under conditions similar to those in the gastrointestinal tract. Given the efficacy of hydrogen in the treatment of conditions associated with oxidative stress, we examined whether the Si-based agent had beneficial effects on the development of renal failure. The Si-based agent was orally administered to rats that were developing renal failure. Rats underwent 5/6 nephrectomy to establish a remnant kidney model. Specifically, on day -7, rats underwent right 2/3 nephrectomy, followed by light nephrectomy on day 0. Starting on day -3, the rats were administered a control or Si-based agent-containing diet for 8 weeks. Compared with the findings in control rats, the Si-based agent greatly suppressed the increases of both serum creatinine and urinary protein levels. All analyzed parameters of oxidative stress were significantly suppressed in the Si-based agent groups. Histopathological examination illustrated that glomerular hypertrophy was suppressed by the treatment. Quantitative real-time reverse transcription-polymerase chain reaction revealed that sirtuin 1 and heme oxygenase-1 expression was increased in the Si-based agent groups, suggesting improved antioxidant activity and reduced hypoxia. In addition, caspase-3 and interleukin-6 expression was suppressed in the Si-based agent groups, indicating the alleviation of apoptosis and inflammation. In conclusion, oral administration of a Si-based agent resulted in renoprotective effects, presumably by suppressing oxidative stress via hydrogen generation.


Asunto(s)
Antioxidantes/farmacología , Creatinina/sangre , Hidrógeno/farmacología , Fallo Renal Crónico/tratamiento farmacológico , Riñón/efectos de los fármacos , Estrés Oxidativo/efectos de los fármacos , Silicio/farmacología , Administración Oral , Animales , Caspasa 3/genética , Caspasa 3/metabolismo , Hipoxia de la Célula , Modelos Animales de Enfermedad , Regulación hacia Abajo , Hemo-Oxigenasa 1/genética , Hemo-Oxigenasa 1/metabolismo , Hidrógeno/uso terapéutico , Interleucina-6/genética , Interleucina-6/metabolismo , Riñón/citología , Riñón/metabolismo , Riñón/patología , Fallo Renal Crónico/patología , Masculino , Nefrectomía , Ratas , Ratas Sprague-Dawley , Silicio/química , Silicio/uso terapéutico , Sirtuina 1/genética , Sirtuina 1/metabolismo , Regulación hacia Arriba
3.
J Emerg Med ; 56(3): 298-300, 2019 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-30661820

RESUMEN

BACKGROUND: Superficial skin abscesses are commonly encountered in emergency medicine practice. Standard treatment includes incision, drainage, and often packing with a gauze strip. The packing component of the procedure has several negative potential outcomes, is painful, and necessitates a return visit for removal. DISCUSSION: Here we report the first case in which a novel silicon packing device was utilized. The patient presented with a facial abscess, which was incised and drained. The novel device was inserted, and removed by the patient independently, without complication. Both patient and provider reported satisfaction with the novel procedure, and noted low pain scores. CONCLUSIONS: This device has the potential to replace traditional packing, and will require further study through a controlled trial to assess for safety and efficacy.


Asunto(s)
Absceso/cirugía , Silicio/uso terapéutico , Cuidados de la Piel/instrumentación , Adulto , Vendajes/normas , Humanos , Maxilares/efectos de los fármacos , Maxilares/lesiones , Masculino , Silicio/farmacología , Cuidados de la Piel/métodos , Cuidados de la Piel/tendencias , Herida Quirúrgica , Cicatrización de Heridas/efectos de los fármacos
4.
Croat Med J ; 60(6): 503-507, 2019 Dec 31.
Artículo en Inglés | MEDLINE | ID: mdl-31894915

RESUMEN

AIM: To establish whether covering the tympanic membrane perforation after war blast injury with silicon foil can enhance the ear drum healing rate and to determine the appropriate timing of silicon patching. METHODS: We retrospectively analyzed the charts of 210 patients wounded during the Homeland War in Croatia 1991-1995, with 315 blast tympanic membrane perforations. In 44 patients (61 perforations), the eardrum perforation was covered by silicon foil, whereas in 166 patients (254 perforations) it was left to heal spontaneously. The patients who underwent the patching procedure were divided in two groups according to the time period between the blast injury and the procedure: 38 perforations were treated within 3 days and 23 perforations were treated 4 to 6 days after the blast injury. RESULTS: The rate of tympanic membrane healing in the silicon foil patching group was significantly higher (91.8%) than that in the group of perforations left to heal spontaneously (79.9%, P=0.029). The healing rate was significantly higher in the group treated within 3 days after the blast injury (97.4%) than in the group treated 4 to 6 days after the injury (82.6%, P=0.042). CONCLUSION: Covering the perforation after the war blast injury with silicon foil significantly improves the rate of tympanic membrane healing. To obtain the best healing outcome, the procedure should be performed within the first 72 hours after the trauma.


Asunto(s)
Traumatismos por Explosión/cirugía , Silicio/uso terapéutico , Perforación de la Membrana Timpánica/cirugía , Cicatrización de Heridas , Adulto , Croacia , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Factores de Tiempo , Resultado del Tratamiento , Membrana Timpánica/lesiones , Membrana Timpánica/cirugía , Perforación de la Membrana Timpánica/etiología , Adulto Joven
5.
J Prosthodont ; 28(1): e431-e433, 2019 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-28387982

RESUMEN

Precise orientation and transfer of the selected path of insertion and removal is a critical step in cast removable partial denture prosthesis design. An easy technique for registering the same is described using addition silicon putty and a used diamond disk.


Asunto(s)
Diseño de Dentadura/métodos , Dentadura Parcial Removible , Técnica de Colado Dental , Materiales Dentales/uso terapéutico , Diseño de Dentadura/instrumentación , Humanos , Silicio/uso terapéutico
6.
J Plant Res ; 131(6): 1015-1028, 2018 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-29357048

RESUMEN

Boron (B) toxicity often limits crop yield and the quality of production in agricultural areas. Here, we investigated the effects of calcium (Ca), silicon (Si) and salicylic acid (SA) on development of B toxicity, B allocation in canola (Brassica napus cultivar Sarw 4) and its role in non-enzymatic antioxidants in relation to yield of this cultivar under B toxicity. Canola seedlings were subjected to four B levels induced by boric acid in the absence or presence of Ca, Si and SA. The results showed that Ca, Si and SA addition ameliorated the inhibition in canola growth, water content (WC), and improved siliqua number, siliqua weight and seed index. The B content in shoots and roots and total B accumulation in the whole plant were increased in control plants under B-toxicity-stress, and these parameters were significantly decreased by addition of Ca, Si and SA. The shoot ascorbate pool (ascorbate, AsA, and dehydroascorbate, DHA), α-tocopherol and phenolics (free and bound) were increased under B toxicity, and were significantly decreased in most cases by addition of Ca, Si and SA, except α-tocopherol, which increased at low B levels (0, 25 and 50 mg kg soil-1). The glutathione content did not obviously change by B stress, while added Ca, Si and SA inhibited its accumulation under B stress. In addition, B toxicity reduced the shoot flavonoids content; however, this reduction was not alleviated by the use of Ca, Si and SA treatments. It could be concluded that growth and yield of canola plants grown under high B concentration improved after external application of Ca, Si or SA.


Asunto(s)
Boro/toxicidad , Brassica napus/efectos de los fármacos , Calcio/uso terapéutico , Ácido Salicílico/uso terapéutico , Silicio/uso terapéutico , Estrés Fisiológico/efectos de los fármacos , Brassica napus/crecimiento & desarrollo , Brassica napus/metabolismo , Glutatión/metabolismo , Raíces de Plantas/efectos de los fármacos , Brotes de la Planta/efectos de los fármacos , Vitamina E/metabolismo
7.
J Nutr ; 147(6): 1104-1112, 2017 06.
Artículo en Inglés | MEDLINE | ID: mdl-28446627

RESUMEN

Background: Lipoapoptosis has been identified as a key event in the progression of nonalcoholic fatty liver disease (NAFLD), and hence, antiapoptotic agents have been recommended as a possible effective treatment for nonalcoholic steatohepatitis (NASH). Silicon, included in meat as a functional ingredient, improves lipoprotein profiles and liver antioxidant defenses in aged rats fed a high-saturated fat, high-cholesterol diet (HSHCD). However, to our knowledge, the antiapoptotic effect of this potential functional meat on the liver has never been tested.Objective: This study was designed to evaluate the effect of silicon on NASH development and the potential antiapoptotic properties of silicon in aged rats.Methods: One-year-old male Wistar rats weighing ∼500 g were fed 3 experimental diets containing restructured pork (RP) for 8 wk: 1) a high-saturated fat diet, as an NAFLD control, with 16.9% total fat, 0.14 g cholesterol/kg diet, and 46.8 mg SiO2/kg (control); 2) the HSHCD as a model of NASH, with 16.6% total fat, 16.3 g cholesterol/kg diet, and 46.8 mg SiO2/kg [high-cholesterol diet (Chol-C)]; and 3) the HSHCD with silicon-supplemented RP with amounts of fat and cholesterol identical to those in the Chol-C diet, but with 750 mg SiO2/kg (Chol-Si). Detailed histopathological assessments were performed, and the NAFLD activity score (NAS) was calculated. Liver apoptosis and damage markers were evaluated by Western blotting and immunohistochemical staining.Results: Chol-C rats had a higher mean NAS (7.4) than did control rats (1.9; P < 0.001). The score in Chol-Si rats (5.4) was intermediate and different from that in both other groups (P < 0.05). Several liver apoptosis markers-including hepatocyte terminal deoxynucleotidyl transferase 2'-deoxyuridine 5'-triphosphate (dUTP) nick end labeling, cytosolic cytochrome c, apoptosis-inducing factor, caspases 9 and 3, and the mitochondrial Bcl-2-associated X protein (BAX)-to-B-cell lymphoma 2 (BCL2) ratio-were 9-45% lower in Chol-Si than in Chol-C rats (P < 0.05) and did not differ from values in the control group.Conclusions: Supplemental silicon substantially affects NASH development in aged male Wistar rats fed an HSHCD by partially blocking apoptosis. These results suggest that silicon-enriched RP could be used as an effective nutritional strategy in preventing NASH.


Asunto(s)
Apoptosis/efectos de los fármacos , Colesterol en la Dieta/administración & dosificación , Dieta Alta en Grasa , Hígado/efectos de los fármacos , Enfermedad del Hígado Graso no Alcohólico/prevención & control , Carne Roja , Silicio/uso terapéutico , Animales , Biomarcadores/metabolismo , Colesterol en la Dieta/metabolismo , Hígado/metabolismo , Hígado/patología , Masculino , Enfermedad del Hígado Graso no Alcohólico/etiología , Enfermedad del Hígado Graso no Alcohólico/metabolismo , Enfermedad del Hígado Graso no Alcohólico/patología , Ratas Wistar , Silicio/farmacología , Dióxido de Silicio/farmacología , Dióxido de Silicio/uso terapéutico , Porcinos , Oligoelementos/farmacología , Oligoelementos/uso terapéutico
8.
J Nanosci Nanotechnol ; 16(2): 1375-8, 2016 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-27433589

RESUMEN

In present society, the technology in various field has been sharply developed and advanced. In medical technology, especially, photothermal therapy and photodynamic therapy have had limelight for curing cancers and diseases. The study investigates the photothermal therapy that reduces side effects of existing cancer treatment, is applied to only cancer cells, and dose not harm any other normal cells. The photothermal properties of porous silicon for therapy are analyzed in order to destroy cancer cells that are more weak at heat than normal ones. For improving performance of porous silicon, it also analyzes the properties when irradiating the near infrared by heterologously junction TiO2 and TiO2NW, photocatalysts that are very stable and harmless to the environment and the human body, to porous silicon. Each sample of Si, PSi, TiO2/Psi, and TiO2NW/PSi was irradiated with 808 nm near-IR of 300, 500, and 700 mW/cm2 light intensity, where the maximum heating temperature was 43.8, 61.6, 67.9, and 61.9 degrees C at 300 mW/cm2; 54.1, 64.3, 78.8, and 68.9 degrees C at 500 mW/cm2; and 97.3, 102.8, 102.5, and 95 0C at 700 mW/cm2. The time required to reach the maximum temperature was less than 10 min for every case. The results indicate that TiO2/PSi thin film irradiated with a single near-infrared wavelength of 808 nm, which is known to have the best human permeability, offers the potential of being the most successful photothermal cancer therapy agent. It maximizes the photo-thermal characteristics within the shortest time, and minimizes the adverse effects on the human body.


Asunto(s)
Silicio/química , Titanio/química , Humanos , Rayos Infrarrojos/uso terapéutico , Fototerapia/métodos , Porosidad , Silicio/uso terapéutico , Neoplasias Cutáneas/terapia , Titanio/uso terapéutico
9.
Biochem Biophys Res Commun ; 434(2): 217-22, 2013 May 03.
Artículo en Inglés | MEDLINE | ID: mdl-23535374

RESUMEN

The applicability of ultrasmall uncapped and aminosilanized oxidized silicon nanoparticles (SiNPs and NH2-SiNPs) as radiosensitizer was studied by internalizing these nanoparticles into human breast cancer (MCF-7) and mouse fibroblast cells (3T3) that were exposed to X-rays at a single dose of 3 Gy. While SiNPs did not increase the production of reactive oxygen species (ROS) in X-ray treated cells, the NH2-SiNPs significantly enhanced the ROS formation. This is due to the amino functionality as providing positive surface charges in aqueous environment. The NH2-SiNPs were observed to penetrate into the mitochondrial membrane, wherein these nanoparticles provoked oxidative stress. The NH2-SiNPs induced mitochondrial ROS production was confirmed by the determination of an increased malondialdehyde level as representing a gauge for the extent of membrane lipid peroxidation. X-ray exposure of NH2-SiNPs incubated MCF-7 and 3T3 cells increased the ROS concentration for 180%, and 120%, respectively. Complementary cytotoxicity studies demonstrate that these silicon nanoparticles are more cytotoxic for MCF-7 than for 3T3 cells.


Asunto(s)
Nanopartículas/uso terapéutico , Fármacos Sensibilizantes a Radiaciones/uso terapéutico , Silicio/uso terapéutico , Células 3T3 , Animales , Antineoplásicos/uso terapéutico , Supervivencia Celular/efectos de los fármacos , Citosol/química , Ensayos de Selección de Medicamentos Antitumorales/métodos , Humanos , Células MCF-7 , Ratones , Microscopía Electrónica de Transmisión , Mitocondrias/química , Mitocondrias/efectos de los fármacos , Membranas Mitocondriales/química , Membranas Mitocondriales/efectos de los fármacos , Nanopartículas/química , Nanotecnología/métodos , Neoplasias/tratamiento farmacológico , Neoplasias/patología , Neoplasias/radioterapia , Oxidación-Reducción , Estrés Oxidativo , Tamaño de la Partícula , Fármacos Sensibilizantes a Radiaciones/química , Especies Reactivas de Oxígeno/química , Silicio/química , Rayos X
10.
Sci Rep ; 13(1): 5707, 2023 04 07.
Artículo en Inglés | MEDLINE | ID: mdl-37029197

RESUMEN

Interstitial pneumonia (IP) is a collective term for diseases whose main lesion is fibrosis of the pulmonary interstitium, and the prognosis associated with acute exacerbation of these conditions is often poor. Therapeutic agents are limited to steroids, immunosuppressants, and antifibrotic drugs, which and have many side effects; therefore, the development of new therapeutic agents is required. Because oxidative stress contributes to lung fibrosis in IP, optimal antioxidants may be effective for the treatment of IP. Silicon (Si)-based agents, when administered orally, can continuously generate a large amount of antioxidant hydrogen in the intestinal tract. In this study, we investigated the effect of our Si-based agent on methotrexate-induced IP, using the IP mouse models. Pathological analysis revealed that interstitial hypertrophy was more significantly alleviated in the Si-based agent-treated group than in the untreated group (decreased by about 22%; P < 0.01). Moreover, additional morphological analysis demonstrated that infiltration of immune cells and fibrosis in the lungs were significantly inhibited by treatment with the Si-based agent. Furthermore, Si-based agent reduced oxidative stress associated with IP by increasing blood antioxidant activity. (increased by about 43%; P < 0.001). Taken together, these results suggest that Si-based agents can be effective therapeutic agents for IP.


Asunto(s)
Enfermedades Pulmonares Intersticiales , Fibrosis Pulmonar , Ratones , Animales , Silicio/uso terapéutico , Enfermedades Pulmonares Intersticiales/diagnóstico , Pulmón/patología , Fibrosis Pulmonar/patología , Pronóstico
11.
ACS Nano ; 17(21): 21539-21552, 2023 Nov 14.
Artículo en Inglés | MEDLINE | ID: mdl-37843009

RESUMEN

The occurrence and development of inflammatory bowel diseases (IBDs) are inextricably linked to the excessive production of reactive oxygen species (ROS). Thus, there is an urgent need to develop innovative tactics to combat IBDs and scavenge excess ROS from affected areas. Herein, silicon hydrogen nanoparticles (SiH NPs) with ROS-scavenging ability were prepared by etching Si nanowires (NWs) with hydrogen fluoride (HF) to alleviate the symptoms associated with IBD by orally targeting the inflamed colonic sites. The strong reductive Si-H bonds showed excellent stability in the gastric and intestinal fluids, which exhibited efficient ROS-scavenging effects to protect cells from high oxidative stress-induced death. After oral delivery, the negatively charged SiH NPs were specifically adsorbed to the positively charged inflammatory epithelial tissues of the colon for an extended period via electrostatic interactions to prolong the colonic residence time. SiH NPs exhibited significant preventive and therapeutic effects in dextran sodium sulfate-induced prophylactic and therapeutic mouse models by inhibiting colonic shortening, reducing the secretion of pro-inflammatory cytokines, regulating macrophage polarization, and protecting the colonic barrier. As determined using 16S rDNA high-throughput sequencing, the oral administration of SiH NPs treatment led to changes in the abundance of the intestinal microbiome, which improved the bacterial diversity and restored the relative abundance of beneficial bacteria after the inflamed colon. Overall, our findings highlight the broad application of SiH-based anti-inflammatory drugs in the treatment of IBD and other inflammatory diseases.


Asunto(s)
Enfermedades Inflamatorias del Intestino , Nanoestructuras , Silicio , Animales , Ratones , Antiinflamatorios/uso terapéutico , Bacterias , Colon , Modelos Animales de Enfermedad , Enfermedades Inflamatorias del Intestino/tratamiento farmacológico , Especies Reactivas de Oxígeno , Silicio/farmacología , Silicio/uso terapéutico
12.
ACS Appl Mater Interfaces ; 15(47): 54221-54233, 2023 Nov 29.
Artículo en Inglés | MEDLINE | ID: mdl-37962427

RESUMEN

The redox-active metal ions, especially Cu2+, are highly correlated to Alzheimer's disease (AD) by causing metal ion-mediated oxidative stress and toxic metal-bound ß-amyloid (Aß) aggregates. Numerous pieces of evidence have revealed that the regulation of metal homeostasis could be an effective therapeutic strategy for AD. Herein, in virtue of the interaction of both amino-containing silane and ethylenediaminetetraacetic acid disodium salt for Cu2+, the silicon-carbon dots (SiCDs) are deliberately prepared using these two raw materials as the cocarbon source; meanwhile, to realize the local enrichment of SiCDs and further maximize the chelating ability to Cu2+, the SiCDs are feasibly loaded to the biocompatible mesoporous silica nanoparticles (mSiO2) with the interaction between residual silane groups on SiCDs and silanol groups of mSiO2. Thus-obtained nanocomposites (i.e., mSiO2@SiCDs) could serve as an efficient Cu2+ chelator with satisfactory metal selectivity and further modulate the enzymic activity of free Cu2+ and the Aß42-Cu2+ complex to alleviate the pathological oxidative stress with an anti-inflammatory effect. Besides, mSiO2@SiCDs show an inspiring inhibitory effect on Cu2+-mediated Aß aggregation and further protect the neural cells against the toxic Aß42-Cu2+ complex. Moreover, the transgenic Caenorhabditis elegans CL2120 assay demonstrates the protective efficacy of mSiO2@SiCDs on Cu2+-mediated Aß toxicity in vivo, indicating its potential for AD treatment.


Asunto(s)
Enfermedad de Alzheimer , Humanos , Enfermedad de Alzheimer/tratamiento farmacológico , Enfermedad de Alzheimer/patología , Silicio/uso terapéutico , Silanos , Dióxido de Silicio/uso terapéutico , Carbono/uso terapéutico , Cobre/farmacología , Péptidos beta-Amiloides/metabolismo , Estrés Oxidativo , Metales , Quelantes/farmacología
13.
Acc Chem Res ; 44(10): 979-89, 2011 Oct 18.
Artículo en Inglés | MEDLINE | ID: mdl-21902173

RESUMEN

Over the last few decades a great variety of nanotechnology based platforms have been synthesized and fabricated to improve the delivery of active compounds to a disease site. Nanoparticles currently used in the clinic, and the majority of nanotherapeutics/nanodiagnostics under investigation, accommodate single- or multiple- functionalities on the same entity. Because many heterogeneous biological barriers can prevent therapeutic and imaging agents from reaching their intended targets in sufficient concentrations, there is an emerging requirement to develop a multimodular nanoassembly, in which different components with individual specific functions act in a synergistic manner. The multistage nanovectors (MSVs) were introduced in 2008 as the first system of this type. It comprises several nanocomponents or "stages", each of which is designed to negotiate one or more biological barriers. Stage 1 mesoporous silicon particles (S1MPs) were rationally designed and fabricated in a nonspherical geometry to enable superior blood margination and to increase cell surface adhesion. The main task of S1MPs is to efficiently transport nanoparticles that are loaded into their porous structure and to protect them during transport from the administration site to the disease lesion. Semiconductor fabrication techniques including photolithography and electrochemical etching allow for the exquisite control and precise reproducibility of S1MP physical characteristics such as geometry and porosity. Furthermore, S1MPs can be chemically modified with negatively/positively charged groups, PEG and other polymers, fluorescent probes, contrast agents, and biologically active targeting moieties including antibodies, peptides, aptamers, and phage. The payload nanoparticles, termed stage 2 nanoparticles (S2NPs), can be any currently available nanoparticles such as liposomes, micelles, inorganic/metallic nanoparticles, dendrimers, and carbon structures, within the approximate size range of 5-100 nm in diameter. Depending upon the physicochemical features of the S1MP (geometry, porosity, and surface modifications), a variety of S2NPs or nanoparticle "cocktails" can be loaded and efficiently delivered to the disease site. As demonstrated in the studies reviewed here, once the S2NPs are loaded into the S1MPs, a variety of novel properties emerge, which enable the design of new and improved imaging contrast agents and therapeutics. For example, the loading of the MRI Gd-based contrast agents onto hemispherical and discoidal S1MPs significantly increased the longitudal relaxivity (r1) to values of up to 50 times larger than those of clinically available gadolinium-based agents (~4 mM(-1) s(-1)/Gd(3+) ion). Furthermore, administration of a single dose of MSVs loaded with neutral nanoliposomes containing small interfering RNA (siRNA) targeted against the EphA2 oncoprotein enabled sustained EphA2 gene silencing for at least 21 days. As a result, the tumor burden was reduced in an orthotopic mouse model of ovarian cancer. We envision that the versatility of the MSV platform and its emerging properties will enable the creation of personalized solutions with broad clinical implications within and beyond the realm of cancer theranostics.


Asunto(s)
Medios de Contraste/uso terapéutico , Diagnóstico por Imagen/métodos , Nanoestructuras/uso terapéutico , Terapéutica/métodos , Animales , Medios de Contraste/química , Medios de Contraste/metabolismo , Humanos , Espacio Intracelular/metabolismo , Nanoestructuras/química , Silicio/química , Silicio/metabolismo , Silicio/uso terapéutico
14.
Phys Chem Chem Phys ; 14(40): 13890-902, 2012 Oct 28.
Artículo en Inglés | MEDLINE | ID: mdl-22968392

RESUMEN

Although porous silicon (pSi) was first obtained in the mid-20th century, considerable interest in this material arose much later, due to the discovery of its room-temperature photoluminescence (PL). In the 1990s, most studies on pSi were focused on the analysis and explanation of its photoluminescent and electroluminescent characteristics and their potential practical applications. The latest advances in pSi research are related to its biocompatibility and biomedical applications. The discovery of singlet oxygen generation by pSi through nonradiative transfer of photoexcitation energy has opened new prospects for photodynamic therapy in vivo, and the discovery of laser desorption/ionization on pSi has paved the way for advanced approaches in mass-spectrometry. In this study, the main photophysical properties of pSi are reviewed, and a wide range of photo-processes characteristic of pSi and their practical implications are analyzed in terms of the general principles of energy and charge transfer. Special attention is paid to the possible applications of pSi and pSi-based nanocomposites in photonics, biophysics, medicine, and analytical chemistry.


Asunto(s)
Materiales Biocompatibles/química , Materiales Biocompatibles/uso terapéutico , Nanocompuestos/química , Silicio/química , Silicio/uso terapéutico , Animales , Transferencia de Energía , Humanos , Porosidad
16.
Med Phys ; 49(6): 4056-4070, 2022 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-35315526

RESUMEN

PURPOSE: Silicon diodes are often the detector of choice for relative dose measurements, particularly in the context of radiotherapy involving small photon beams. However, a major drawback lies in their dose-rate dependency. Although ionization chambers are often too large for small field output factor (OF) measurements, they are valuable instruments to provide reliable percent-depth dose (PDD) curves in reference beams. The aim of this work is to propose a practical and accurate method for the characterization of silicon diode dose-rate dependence correction factors using ionization chamber measurements as a reference. METHODS: The robustness of ionization chambers for PDD measurements is used to quantify the dose-rate dependency of a diode detector. A mathematical formalism, which exploits the error induced in percent-depth ionization (PDI) curves for diodes by their dose-rate dependency, is developed to derive a dose-rate correction factor applicable to diode relative measurements. The method is based on the definition of the recombination correction factor given in the addendum to TG 51 and is applied to experimental measurements performed on a CyberKnife M6 radiotherapy unit using a PTW 60012 diode detector. A measurement-based validation is provided by comparing corrected PDI curves to measurements performed with a PTW 60019 diamond detector, which does not exhibit dose-rate dependence. RESULTS: Results of dose-rate correction factors for PDI curves, off-axis ratios (OARs), tissue-phantom ratios, and small field OFs are coherent with the expected behavior of silicon diode detectors. For all considered setups and field sizes, the maximum correction and the maximum impact of the uncertainties induced by the correction are obtained for OARs for the 60 mm collimator, with a correction of 2.5% and an uncertainty of 0.34%. For OFs, corrections range from 0.33% to 0.82% for all field sizes considered, and increase with the reduction of the field size. Comparison of PDI curves corrected for dose-rate and for in-depth beam quality variations illustrates excellent agreement with measurements performed using the diamond detector. CONCLUSION: The proposed method allows the efficient and precise correction of the dose-rate dependence of silicon diode detectors in the context of clinical relative dosimetry.


Asunto(s)
Radiometría , Silicio , Diamante , Fantasmas de Imagen , Radiometría/métodos , Dosificación Radioterapéutica , Silicio/química , Silicio/uso terapéutico , Incertidumbre
17.
ACS Appl Bio Mater ; 5(8): 3936-3950, 2022 08 15.
Artículo en Inglés | MEDLINE | ID: mdl-35802827

RESUMEN

Colorectal cancer ranks as the third most lethal cancer worldwide, resulting in over 1 million cases and 900 000 deaths per year. According to population-based studies, administration of long-term non-steroidal anti-inflammatory drugs (NSAIDs) was proven to reduce the risk of a subject developing colorectal cancer. In the present study, the anti-cancer activity of two different NSAIDs, sulindac- (Pc-1) or diclofenac-substituted (Pc-2) asymmetric silicon phthalocyanine derivatives, was evaluated in four different colorectal cancer cell lines bearing various carcinogenic mutations. In this context, the IC50 values of each compound after 24 and 48 h were determined on HCT116, SW480, LoVo, and HT29 cell lines, and the effects of the compounds on programmed cell death pathways apoptosis and autophagy, their impact on cell cycle progression, and the effect of NSAID moieties they bear on COX-1 and COX-2 proteins were analyzed. In addition, the photophysical and photochemical properties of a synthesized Pc derivative bearing axial diclofenac and triethylene glycol groups (Pc-2) have been investigated, and the compound has been characterized by using different analytical techniques. Our results indicated that both compounds inhibit COX protein expression levels, activate apoptosis in all cell lines, and lead to cell cycle arrest in the G2/M phase, depending on the COX expression profiles of the cell lines, indicating that NSAIDs can be coupled with Pc's to achieve increased anti-cancer activity, especially on cancer cells known to have high COX activity.


Asunto(s)
Neoplasias Colorrectales , Inhibidores de la Ciclooxigenasa , Antiinflamatorios no Esteroideos/farmacología , Neoplasias Colorrectales/tratamiento farmacológico , Inhibidores de la Ciclooxigenasa/farmacología , Diclofenaco/farmacología , Células HT29 , Humanos , Indoles , Compuestos de Organosilicio , Silicio/uso terapéutico
18.
ACS Biomater Sci Eng ; 8(10): 4163-4174, 2022 10 10.
Artículo en Inglés | MEDLINE | ID: mdl-34196517

RESUMEN

Glioblastoma multiforme (GBM) is the most aggressive malignant tumor. It is difficult to regulate GBM using conventional chemotherapy-based methods due to its anatomical structure specificity, low drug targeting ability, and limited penetration depth capability to reach the tumor interior. Numerous approaches have been proposed to overcome such issues, including nanoparticle-based drug delivery system (DDS) with the development of GBM site targeting and penetration depth enhancing moieties (e.g., peptides, sugars, proteins, etc.). In this study, we prepared four different types of nanoparticles, which are based on porous silicon nanoparticles (pSiNPs) incorporating polyethylene glycol (PEG), iRGD peptide (well-known cancer targeting peptide), and SIWV tetra-peptide (a recently disclosed GBM-targeting peptide), and analyzed their deep-tumor penetration abilities in cell spheroids, in GBM patient-derived tumoroids, and in GBM xenograft mice. We found that SIWV tetra-peptide significantly enhanced the penetration depth of pSiNPs, and its therapeutic formulation (temozolomide-loaded/SIWV-functionalized pSiNPs) showed a higher anticancer efficacy compared with other formulations. These findings hold great promise for the development of nanotherapeutics and peptide-conjugated drugs for GBM.


Asunto(s)
Glioblastoma , Animales , Línea Celular Tumoral , Glioblastoma/tratamiento farmacológico , Glioblastoma/metabolismo , Glioblastoma/patología , Humanos , Ratones , Péptidos/química , Péptidos/farmacología , Péptidos/uso terapéutico , Polietilenglicoles/química , Polietilenglicoles/uso terapéutico , Silicio/química , Silicio/uso terapéutico , Azúcares/uso terapéutico , Temozolomida/uso terapéutico
19.
Andrology ; 9(1): 376-383, 2021 01.
Artículo en Inglés | MEDLINE | ID: mdl-32799427

RESUMEN

BACKGROUND: Varicocoele-induced male infertility potentially involves oxidative stress. Although varicocoelectomy is recommended for varicocoele patients presenting abnormal semen findings, no pharmacotherapeutic methods currently exist. We have recently developed a silicon-based agent that produces hydrogen by the reaction with water. OBJECTIVES: This study aimed to investigate the therapeutic effects of oral administration of a Si-based agent on varicocoele rat. MATERIALS AND METHODS: Twenty-one rats were divided into four groups: varicocoele + normal diet (n = 5), varicocoele + Si-based agent-supplemented diet (n = 6), sham + normal diet (n = 5), and sham + Si-based agent-supplemented diet (n = 5). All rats were euthanized four weeks after surgery. RESULTS: The mean left epididymal sperm motility was 74.4% in the sham group, 72.3% in the sham + Si group, 57.6% in the varicocoele group, and 66.9% in the varicocoele + Si group. Epididymal sperm motility was significantly lower in the varicocoele group, but was significantly higher upon Si-based agent ingestion (P < .01). The mean left testicular weight, Johnsen's score, and left epididymal sperm concentration did not differ significantly between groups. The 8-OHdG concentration and DNA fragmentation rate were significantly increased in the varicocoele group, but were significantly decreased in the Si-based agent intake group (P < .01). Additionally, the IVF rate was significantly lower in the varicocoele group (26.3%) compared with the sham group (73.4%; P < .01), and was significantly higher in the varicocoele + Si group (51.8%) compared with the varicocoele group (P < .05), indicating that the Si-based agent improves IVF rates. DISCUSSION AND CONCLUSION: Oral intake of the silicon-based agent improves epididymal sperm motility and in vitro fertilization rates through hydrogen production and subsequent reduction of oxidative stress. Considering the lack of effective noninvasive methods, this Si-based agent is potentially applicable for treating varicocoele-induced abnormal semen parameters.


Asunto(s)
Fertilización In Vitro/estadística & datos numéricos , Hidrógeno/uso terapéutico , Silicio/uso terapéutico , Varicocele/dietoterapia , Animales , Suplementos Dietéticos , Masculino , Estrés Oxidativo , Ratas Sprague-Dawley , Motilidad Espermática
20.
Viruses ; 13(11)2021 10 26.
Artículo en Inglés | MEDLINE | ID: mdl-34834964

RESUMEN

A transmissible gastroenteritis virus (TGEV) is a porcine enteropathogenic coronavirus, causing acute swine enteric disease especially in suckling piglets. Mesoporous silica nanoparticles (MSNs) are safe vaccine adjuvant, which could enhance immune responses. Our previous research confirmed that nano silicon had immune-enhancing effects with inactivated TGEV vaccine. In this study, we further clarified the immune-enhancing mechanism of the inactivated TGEV vaccine with MSNs on porcine dendritic cells (DCs). Our results indicated that the inactivated TGEV vaccine with MSNs strongly enhanced the activation of the DCs. Expressions of TLR3, TLR5, TLR7, TLR9, and TLR10, cytokines IFN-α, IL-1ß, IL-6, IL-12, and TNF-α, cytokine receptor CCR-7 of immature DCs were characterized and showed themselves to be significantly higher in the inactivated TGEV vaccine with the MSN group. In summary, the inactivated TGEV vaccine with MSNs has effects on the phenotype and function of porcine DCs, which helps to better understand the immune-enhancing mechanism.


Asunto(s)
Citocinas/metabolismo , Células Dendríticas/inmunología , Gastroenteritis Porcina Transmisible/inmunología , Gastroenteritis Porcina Transmisible/prevención & control , Receptores Toll-Like/metabolismo , Virus de la Gastroenteritis Transmisible/inmunología , Vacunas de Productos Inactivados/inmunología , Adyuvantes de Vacunas/uso terapéutico , Animales , Citocinas/inmunología , Células Dendríticas/citología , Femenino , Inmunidad Innata , Nanopartículas/uso terapéutico , Fenotipo , Silicio/uso terapéutico , Porcinos , Receptores Toll-Like/inmunología , Vacunas de Productos Inactivados/uso terapéutico
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