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Introduction: Thrombogenesis, a major cause of implantable cardiovascular device failure, can be addressed through the use of biodegradable polymers modified with anticoagulating moieties. This study introduces a novel polyester urethane urea (PEUU) functionalized with various anti-platelet deposition molecules for enhanced antiplatelet performance in regenerative cardiovascular devices. Methods: PEUU, synthesized from poly-caprolactone, 1,4-diisocyanatobutane, and putrescine, was chemically oxidized to introduce carboxyl groups, creating PEUU-COOH. This polymer was functionalized in situ with polyethyleneimine, 4-arm polyethylene glycol, seleno-L-cystine, heparin sodium, and fondaparinux. Functionalization was confirmed using Fourier-transformed infrared spectroscopy and X-ray photoelectron spectroscopy. Bio-compatibility and hemocompatibility were validated through metabolic activity and hemolysis assays. The anti-thrombotic activity was assessed using platelet aggregation, lactate dehydrogenase activation assays, and scanning electron microscopy surface imaging. The whole-blood clotting time quantification assay was employed to evaluate anticoagulation properties. Results: Results demonstrated high biocompatibility and hemocompatibility, with the most potent anti-thrombotic activity observed on pegylated surfaces. However, seleno-L-cystine and fondaparinux exhibited no anti-platelet activity. Discussion: The findings highlight the importance of balancing various factors and addressing challenges associated with different approaches when developing innovative surface modifications for cardiovascular devices.
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In Costa Rica, two species of Psidium fruits, P. guajava and P. friedrichsthalianum, are widely consumed as food and used in folk medicine. Although studies have revealed the health effects of these fruits, there has been little research showing the antiplatelet activity of these species. This work evaluated the antiplatelet potential of aqueous extracts made from leaves and fruits of pink guava and Costa Rican guava. Platelet aggregation was induced by the platelet agonists ADP, TRAP-6, collagen and PMA. Platelet activation and secretion were studied using flow cytometry. The chemical profiles of the four extracts were characterized using UPLC-DAD-ESI-QTOF-MS. The studies revealed that the aqueous extracts of leaves and fruits of P. guajava and P. friedrichsthalianum inhibited platelet aggregation induced by ADP (4 µM), TRAP-6 (5 µM), collagen (1 µg mL-1) and PMA (100 nM), and the effect was dependent on the extract concentration. Extracts of leaves and fruits of pink guava and Costa Rican guava reduced secretion of P-selectin and activation of GP IIb/IIIa. The extracts of leaves and fruits of pink guava and Costa Rican guava proved to be a rich source of phenolic compounds, mainly quercetin aglycones and proanthocyanidins derived from (epi) catechin units. Other compounds such as ellagitannins, and benzophenones were also putatively identified. This research showed that P. guajava and P. friedrichsthalianum could potentially be used for the prevention of thrombotic events.
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Psidium , Costa Rica , Frutas , Extractos Vegetales/farmacología , Hojas de la Planta , Polifenoles/farmacologíaRESUMEN
This report describes a modified, simple, low-cost and more sensitive method to determine bleeding patterns and haemoglobin concentration in a tail-bleeding assay using BALB/c mice and tail tip amputation. The cut tail was immersed in Drabkin's reagent to promote erythrocyte lysis and haemoglobin release, which was monitored over 30 min. The operator was blinded to individual conditions of the mice, which were treated with either saline (NaCl 0.15m), DMSO (0.5%) or clinical anti-thrombotic drugs. Our experimental protocols showed good reproducibility and repeatability of results when using Drabkin's reagent than water. Thus, the use of Drabkin's reagent offered a simple and low-cost method to observe and quantify the bleeding and rebleeding episodes. We also observed the bleeding pattern and total haemoglobin loss using untreated animals or those under anti-coagulant therapy in order to validate the new Drabkin method and thus confirm that it is a useful protocol to quantify haemoglobin concentrations in tail-bleeding assay. This modified method provided a more accurate results for bleeding patterns in mice and for identifying new anti-thrombotic drugs.
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Fibrinolíticos/farmacología , Hemorragia/tratamiento farmacológico , Cola (estructura animal)/lesiones , Animales , Modelos Animales de Enfermedad , Femenino , Proteínas Ligadas a GPI , Proteína de la Hemocromatosis , Masculino , Proteínas de la Membrana/sangre , Ratones Endogámicos BALB C , Reproducibilidad de los ResultadosRESUMEN
Bromelain is a concoction of sulfhydryl proteolytic enzymes. Depending upon the site of extraction it can be regarded as either stem bromelain (SBM) (EC 3.4.22.32) or fruit bromelain (FBM) (EC 3.4.22.33). Bromelain remain enzymatic active over a broad spectrumand endure a range of pH (5.5 to 8.0) and temperature (35.5 to 71 ºC). It is one of the extensively investigated proteolytic enzyme owing to its astonishing applications in various industries. This necessitated employing a strategy that result in highest purified bromelain in less steps and lowest cost. Use of modernistic approach such as membrane filtration, reverse micellar systems, aqueous two phase extraction and chromatographic techniques have shown promise in this regard. Besides its industrial applications, bromelain has been widely utilized as a potential phytomedical compound. Some of its reported actions include inhibition of platelet aggregation, anti-edematous, anti-thrombotic, anti-inflammatory, modulation of cytokines and immunity, skin debridement and fibrinolytic activity. It also assist digestion, enhance absorption of other drugs and is a potential postoperatively agent that promote wound healing and reduce postsurgical discomfort and swelling.
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JUSTIFICATIVA E OBJETIVOS: O uso de heparina de baixo peso molecular (HBPM) na profilaxia ou terapêutica de diversas doenças ou síndromes é de grande importância na prática clínica. O objetivo deste estudo foi avaliar a segurança e a eficácia da enoxaparina sódica, teste (ENOX-T) comparada ao medicamento de referência (ENOX-R). MÉTODO: Foi realizado estudo prospectivo, aleatório, comparativo, unicêntrico e aberto envolvendo pacientes com indicação de profilaxia ou tratamento antitrombótico. Foram incluídos 100 pacientes divididos em 2 braços: profilático (n = 50) e terapêutico (n = 50) divididos em 2 grupos para cada braço (grupo 1: ENOX-R e grupo 2: ENOX-T). Analisou-se em cada segmento os dados clínicos e laboratoriais. A atividade do anti-fator Xa foi aferida em três momentos: basal (1ª avaliação); 1º ou 2º dia (2ª avaliação) e 5º a 7º dia (3ª avaliação). O ultra-som Doppler dos membros inferiores foi realizado na 2ª ou 3ª avaliação do braço profilático. RESULTADOS: Os resultados demonstraram homogeneidade dos grupos nos 2 braços (profilático e terapêutico) quanto a sexo, idade, índice de massa corpórea, creatinina sérica e Apache II. Os valores do anti-fator Xa nos braços profilático e terapêutico demonstraram eficácia adequada dos medicamentos, sem diferença clínica ou estatística entre ambos. A ocorrência de eventos adversos não mostrou diferença clínica ou estatística entre os medicamentos. No braço profilático o ultra-som de membros inferiores acrescentou informações úteis sobre a eficácia dos fármacos estudados. CONCLUSÕES: A enoxaparina sódica teste (ENOX-T) foi segura e eficaz nos pacientes analisados e equivalente ao medicamento de referência (ENOX-R).
BACKGROUND AND OBJECTIVES: Use of low molecular weight heparins (LMWH), either prophylactic or therapeutic, is of most importance in several syndromes and diseases in daily clinical practice. Our objective in this clinical trial was to evaluate safety and efficacy of test sodium enoxaparin (ENOX-T) compared to the reference drug (ENOX-R). METHODS: We conducted a prospective, randomized, comparative, unicentric and open-labeled trial including patients with either prophylactic or therapeutic anti-thrombotic indications. A total of 100 patients were enrolled in two branches: prophylactic (n=50) and therapeutic (n=50) and two groups for each branch (group 1: ENOX-R and group 2: ENOX-T). We analyzed clinical and laboratory data in each segment. Anti-factor Xa was measured in three different moments: baseline (1st evaluation); 1st or 2nd day (2nd evaluation) and 5th to 7th day (3rd evaluation). Doppler-sonography of inferior limbs was performed on all patients in prophylactic group on 2nd or 3rd evaluation. RESULTS: The data showed that both branches (prophylactic and therapeutic) were homogenous in regard of sex, age, body mass index (BMI), serum creatinine and APACHE II severity score at admission. Anti-factor Xa results, in both prophylactic and therapeutic branches, showed expected efficacy to both drugs, without any clinical or statistical difference between them. Adverse events incurred in both groups in a similar way, without any clinical or statistical difference between them. In prophylactic branch, Doppler-sonography of inferior limbs added useful information on drugs efficacy. CONCLUSIONS: We conclude that test sodium enoxaparin (ENOX-T) was effective and safe in our patient's cohort and equivalent to reference drug (ENOX-R).