RESUMO
The success of microfluidic immunocapture based on magnetic beads depends primarily on a sophisticated microscale separation system and on the quality of the magnetic immunosorbent. A microfluidic chip containing a magnetically stabilized fluidized bed (µMSFB), developed for the capture and on-chip amplification of bacteria, was recently described by Pereiro et al.. The present work shows the thorough development of anti-Salmonella magnetic immunosorbents with the optimal capture efficiency and selectivity. Based on the corresponding ISO standards, these parameters have to be high enough to capture even a few cells of bacteria in a proper aliquot of sample, e.g. milk. The selection of specific anti-Salmonella IgG molecules and the conditions for covalent bonding were the key steps in preparing an immunosorbent of the desired quality. The protocol for immunocapturing was first thoroughly optimized and studied in a batchwise arrangement, and then the carrier was integrated into the µMSFB chip. The combination of the unique design of the chip (guaranteeing the collision of cells with magnetic beads) with the advanced immunosorbent led to a Salmonella cell capture efficiency of up to 99%. These high values were achieved repeatedly even in samples of milk differing in fat content. The rate of nonspecific capture of Escherichia coli (i.e. the negative control) was only 2%.
Assuntos
Separação Imunomagnética/métodos , Leite/química , Salmonella/isolamento & purificação , Animais , Escherichia coli/isolamento & purificação , Imunoglobulina G/química , Separação Imunomagnética/instrumentação , Dispositivos Lab-On-A-Chip , Técnicas Analíticas Microfluídicas/instrumentação , Técnicas Analíticas Microfluídicas/métodos , Microesferas , Salmonella/citologia , Salmonella/imunologiaRESUMO
Screen-printed platinum electrodes as transducer and magnetic beads as solid phase were combined to develop a particle-based electrochemical immunosensor for monitoring the serious food allergen ovalbumin. The standard arrangement of enzyme-linked immunosorbent assay became the basis for designing the immunosensor. A sandwich-type immunocomplex was formed between magnetic particles functionalized with specific anti-ovalbumin immunoglobulin G and captured ovalbumin molecules, and secondary anti-ovalbumin antibodies conjugated with the enzyme horseradish peroxidase were subsequently added as label tag. The electrochemical signal proportional to the enzymatic reaction of horseradish peroxidase during the reduction of hydrogen peroxide with thionine as electron mediator was measured by linear sweep voltammetry. The newly established method of ovalbumin detection exhibits high sensitivity suitable for quantification in the range of 11 to 222nM and a detection limit of 5nM. Magnetic beads-based assay format using external magnets for rapid and simple separation has been proven to be an excellent basis for electrochemical detection and quantification of food allergens in highly complex sample matrices.
Assuntos
Técnicas Biossensoriais/métodos , Hipersensibilidade Alimentar/metabolismo , Imunoensaio/métodos , Imãs/química , Microesferas , Ovalbumina/análise , Animais , Anticorpos Imobilizados/química , Anticorpos Imobilizados/imunologia , Técnicas Biossensoriais/instrumentação , Condutividade Elétrica , Eletroquímica , Eletrodos , Transporte de Elétrons , Imunoensaio/instrumentação , Limite de Detecção , Ovalbumina/efeitos adversos , Platina/químicaRESUMO
PRCIS: Deep sclerectomy (DS) with fibrin adhesive can constitute a safe alternative to the classic procedure using sutures, providing nonallergenic, nontoxic, and secure adhesion with no sign of aqueous humor outflow obstruction postoperatively. OBJECTIVE: To evaluate short and medium-term postoperative results of DS with a fibrin sealant. PATIENTS AND METHODS: This prospective, noncomparative, interventional case series involves 12 eyes of 12 patients with uncontrolled open angle glaucoma who underwent DS with Esnoper (Clip or V2000) implant between February 2021 and March 2022. A novel method of wound closure (sclera, Tenon fascia, and conjunctiva) employing fibrin glue was used instead of classic sutures. Surgical outcomes assessed include: intraocular pressure and glaucoma therapy reduction, best-corrected visual acuity changes, and number of complications registered peri and postoperatively. All measurements were performed preoperatively, as well as at 1 day, at 1 and 2 weeks, and at 1, 2, 3, 6, 9, and 12 months after surgery. RESULTS: The mean intraocular pressure decreased from 24.0 ± 9.1 mm Hg to 13.8 ± 6.3 mm Hg at 1 year postoperatively ( P < 0.001). Kaplan-Meier survival analysis revealed complete and qualified success rates of 83.3% and 91.7%. The mean glaucoma therapy decreased from 3.2 ± 1.1 to 0.8 ± 1.3 drugs 12 months after surgery ( P < 0.001). Nd:YAG goniopunture was performed in 2 eyes at 1 and 12 months postoperatively. No significant best-corrected visual acuity changes were registered. Perioperatively, we noted a trabeculo-descemet microperforation in 1 eye, transient hypotony in 5 eyes, and mild hyphema in 2 eyes. CONCLUSIONS: Fibrin adhesive provided an effective closure in sutureless DS in the patients included in our study. This modification of classical DS may simplify the surgical technique, ensure secure wound adaptation, optimize healing, and lower the risk of inflammation and fibrosis postoperatively.
Assuntos
Adesivo Tecidual de Fibrina , Glaucoma de Ângulo Aberto , Pressão Intraocular , Esclera , Esclerostomia , Procedimentos Cirúrgicos sem Sutura , Adesivos Teciduais , Acuidade Visual , Humanos , Adesivo Tecidual de Fibrina/uso terapêutico , Pressão Intraocular/fisiologia , Masculino , Estudos Prospectivos , Feminino , Esclerostomia/métodos , Glaucoma de Ângulo Aberto/cirurgia , Glaucoma de Ângulo Aberto/fisiopatologia , Idoso , Acuidade Visual/fisiologia , Esclera/cirurgia , Procedimentos Cirúrgicos sem Sutura/métodos , Adesivos Teciduais/uso terapêutico , Pessoa de Meia-Idade , Resultado do Tratamento , Implantes para Drenagem de Glaucoma , Idoso de 80 Anos ou mais , Seguimentos , Tonometria OcularRESUMO
Carbonyl-reducing enzymes are important in both metabolism of endogenous substances and biotransformation of xenobiotics. Because sufficient amounts of native enzymes must be obtained to study their roles in metabolism, an efficient purification strategy is very important. Oracin (6-[2-(2-hydroxyethyl)aminoethyl]-5,11-dioxo-5,6-dihydro-11H-indeno[1,2-c] isoquinoline) is a prospective anticancer drug and one of the xenobiotic substrates for carbonyl-reducing enzymes. A new purification strategy based on molecular recognition of carbonyl-reducing enzymes with oracin as a ligand is reported here. The type of covalent bond, ligand molecules orientation, and their distance from the backbone of the solid matrix for good stearic accessibility were taken into account during the designing of the carrier. The carriers based on magnetically active microparticles were tested by recombinant enzymes AKR1C3 and CBR1. The SiMAG-COOH magnetic microparticles with N-alkylated oracin and BAPA as spacer arm provide required parameters: proper selectivity and specificity enabling to isolate the target enzyme in sufficient quantity, purity, and activity.
Assuntos
Oxirredutases do Álcool/isolamento & purificação , Antineoplásicos/química , Ensaios Enzimáticos/métodos , Enzimas/isolamento & purificação , Etanolaminas/química , Isoquinolinas/química , Magnetismo , Bioensaio , Cromatografia de Afinidade , Cromatografia Líquida de Alta Pressão , Eletroforese em Gel de Poliacrilamida , Ligantes , Microesferas , Estrutura Molecular , Bases de Schiff/químicaRESUMO
PRCIS: Deep sclerectomy (DS) with the Esnoper Clip drainage implant in patients with uncontrolled primary open angle glaucoma (POAG) achieved a complete success rate of 87.2% at the 1-year follow-up. PURPOSE: To investigate the efficacy and safety of DS followed by Esnoper Clip implantation in patients with uncontrolled POAG. MATERIALS AND METHODS: In a prospective, consecutive, interventional study, we investigated 39 eyes of 35 patients with uncontrolled POAG who underwent DS with Esnoper Clip implantation. Complete ophthalmologic examinations including corrected visual acuity and intraocular pressure (IOP), were performed preoperatively, and at 1 day, at 1 week as well as at 1, 3, 6, 9, and 12 months postoperatively. Moreover, any goniopunctures and glaucoma medications required postoperatively were noted. RESULTS: The mean preoperative IOP was 20.8±5.2 mm Hg and it decreased to 13.9±3.1 mm Hg at 1 year postoperatively ( P <0.001). The number of glaucoma medications decreased from 2.9±0.7 preoperatively to 0.3±0.8 after 1 year ( P <0.001). The complete success rate (IOP≤21 mm Hg without glaucoma medication) and the qualified success rate (IOP ≤21 mm Hg with or without glaucoma medication) were 87.2% and 94.9%, respectively. Goniopuncture was performed in 33.3% of cases. No significant corrected visual acuity changes were registered at the final follow-up. Perioperative complications consisted of 3 micro-perforations of the trabeculo-descemet membrane. Postoperative complications included: hyphema (6 eyes), hypotony (6 eyes), shallow anterior chamber (3 eyes), choroidal detachment (4 eyes)-all of which were resolved without surgical intervention during the first postoperative month-and conjunctival dehiscence, which required resuture (2 eyes). CONCLUSION: Deep sclerectomy with the Esnoper Clip implant was safe and effectively lowered IOP in patients with uncontrolled POAG.
Assuntos
Glaucoma de Ângulo Aberto , Esclerostomia , Humanos , Estudos Prospectivos , Pressão Intraocular , Glaucoma de Ângulo Aberto/cirurgia , Instrumentos Cirúrgicos , Resultado do TratamentoRESUMO
Hyaluronic acid (HA) is known to serve as a dynamic mediator intervening in many physiological functions. Its specific effect has been repeatedly confirmed to be strongly influenced by the molecular size of hyaluronan fragments. However common technological approaches of HA fragments production have their limitations. In many cases, the final products do not meet the strict pharmaceutical requirements, specifically due to size polydispersity and reaction contaminants. We present novel methodology based on combination of unique incidental ability of the plant-derived protease papain to split the glycosidic bonds and an indispensable advantages of biocompatible macroporous material with incorporated ferrous ions serving as carrier for covalent papain fixation. This atypical and yet unpublished highly efficient multiparametric approach allows enhanced HA fragmentation for easily and safely producing molar-mass-defined HA fragments with narrow size distribution. Native polyacrylamide gel electrophoresis (PAGE) and size exclusion chromatography/multi-angle light scattering (SEC-MALS) confirmed the effectiveness of our multiparametric approach.
Assuntos
Ácido Hialurônico/química , Celulose/química , Cromatografia em Gel , Enzimas Imobilizadas/química , Hialuronoglucosaminidase/química , Ferro/química , Fenômenos Magnéticos , Peso Molecular , Eletroforese em Gel de Poliacrilamida Nativa , Papaína/química , Espalhamento de Radiação , ViscosidadeRESUMO
Iron oxide based particles functionalized by bioactive molecules have been utilized extensively in biotechnology and biomedicine. Despite their already proven advantages, instability under changing reaction conditions, non-specific sorption of biomolecules on the particles' surfaces, and iron oxide leakage from the naked particles can greatly limit their application. As confirmed many times, surface treatment with an appropriate stabilizer helps to minimize these disadvantages. In this work, we describe enhanced post-synthetic surface modification of superparamagnetic microparticles varying in materials and size using hyaluronic acid (HA) in various chain lengths. Scanning electron microscopy, atomic force microscopy, phase analysis light scattering and laser diffraction are the methods used for characterization of HA-coated particles. The zeta potential and thickness of HA-layer of HA-coated Dynabeads M270 Amine were -50 mV and 85 nm, respectively, and of HA-coated p(GMA-MOEAA)-NH2 were -38 mV and 140 nm, respectively. The electrochemical analysis confirmed the zero leakage of magnetic material and no reactivity of particles with hydrogen peroxide. The rate of non-specific sorption of bovine serum albumin was reduced up to 50% of the naked ones. The coating efficiency and suitability of biopolymer-based microparticles for magnetically active microfluidic devices were confirmed.