RESUMO

The aim of this work was to evaluate in vitro the tromboresistence, hemolysis tendency, platelet adhesion, cytotoxicity, physicochemical properties, and stability of open-heart tubing coated with fractionated heparin-benzalkonium chloride and/or lipid dipalmitoyl L-alpha-phosphatidylcholine (DPPC). The tendency for clot formation and platelet adhesion was greater in noncoated and lipid-coated tubing than in heparin-coated tubing. There were no significant differences between the hemolytic potentials of coated and noncoated tubing. The coatings were stable during the time of the experiment. The coatings did not present cytotoxicity and physicochemical alterations.

Assuntos

Anticoagulantes , Procedimentos Cirúrgicos Cardíacos/instrumentação , Materiais Revestidos Biocompatíveis , Circulação Extracorpórea/instrumentação , Fibrinolíticos , Heparina , Lipídeos , 1,2-Dipalmitoilfosfatidilcolina , Animais , Anticoagulantes/farmacologia , Compostos de Benzalcônio , Sobrevivência Celular/efeitos dos fármacos , Fenômenos Químicos , Físico-Química , Materiais Revestidos Biocompatíveis/farmacologia , Estabilidade de Medicamentos , Estudos de Avaliação como Assunto , Fibrinolíticos/farmacologia , Fibroblastos/efeitos dos fármacos , Hemólise/efeitos dos fármacos , Heparina/farmacologia , Intubação/instrumentação , Lipídeos/farmacologia , Adesividade Plaquetária/efeitos dos fármacos , Cloreto de Polivinila , Conservantes Farmacêuticos , Coelhos , Propriedades de Superfície , Tensoativos , Trombose/prevenção & controle

RESUMO

Cardiopulmonary surgeries need connectors for extracorporeal circulation. The patient's blood in contact with the tube surfaces modifies its plasmatic proteins, promotes platelet aggregation, and activates the complement system, unleashing thrombus formation. Thus, it becomes necessary for an anticoagulant to keep the circuit free from these events. Heparin is the anticoagulant used even after reports about its disadvantages. Platelet adherence seems to be very dependent on the quality from the surfaces that can promote cellular proliferation, aggregation, and thrombosis. In this study, we compare the quality of the heparin-coated and uncoated surfaces. We used a blood cell culture and scanning electron microscopy (SEM) to visualize the platelet aggregation. It was concluded that there are groove areas that permit platelet adherence, and if they are not coated totally by the heparin, aggregation still occurs although in lower scale than on the uncoated tubes.

Assuntos

Anticoagulantes/química , Biopolímeros/química , Heparina/química , Anticoagulantes/farmacologia , Plaquetas/efeitos dos fármacos , Plaquetas/ultraestrutura , Proteínas Sanguíneas/química , Divisão Celular/efeitos dos fármacos , Células Cultivadas , Materiais Revestidos Biocompatíveis/química , Ativação do Complemento/efeitos dos fármacos , Circulação Extracorpórea/instrumentação , Heparina/farmacologia , Humanos , Microscopia Eletrônica de Varredura , Adesividade Plaquetária/efeitos dos fármacos , Agregação Plaquetária/efeitos dos fármacos , Propriedades de Superfície , Trombose/prevenção & controle

RESUMO

The aim of this study was to compare qualitative and quantitative methods for coating characterization on internal surfaces of polyvinyl chloride (PVC) tubing used in procedures of extracorporeal circulation. The methods of characterization included optical microscopy (OM) after dyeing with toluidine blue, scanning electron microscopy (SEM), atomic force microscopy (AFM) and energy dispersive spectrometry (EDS). OM after sample dyeing was excellent in allowing early detection of any absence or irregularities of coatings among the used methods. SEM was the most effective in observing the structure and thickness either in heparin coatings or in lipid coatings. AFM provided a good evaluation of the surface topography. A conjunction of all methods is recommended for complete characterization. The quantification methods based on colorimetric tests were efficient in determining the concentrations of heparin and lipid on internal surface tubes, the coating stability and the reproducibility of the results.