RESUMO
A molecularly imprinted polymer (MIP) capable of detecting bilirubin was successfully synthesized. Bilirubin template was imprinted in poly(methacrylic acid-co-ethylene glycol dimethylacrylate) [poly(MAA-co-EGDMA)]. MAA and EGDMA were used as the monomer and the cross-linker, respectively. The optimal solvent conditions to maintain its stability were discussed. Solvent system based on ethylenediamine tetraacetic acid (EDTA) and ascorbic acid was compared with respect to the stability of bilirubin. pH and bilirubin concentration were both investigated for the bilirubin stability. Blue light as well as aeration was applied to inspect the regarding effects. The cross-linking effect was further confirmed by the thermogravimetric analysis (TGA). The effect of salts, such as NaCl and KCl on the binding capacity of the molecularly imprinted polymer was also discussed. Further, the rat serum and bile samples were applied and the binding of the MIPs for bilirubin was thus confirmed.
Assuntos
Bilirrubina/química , Etilenoglicol/química , Metacrilatos/química , Polímeros/química , Adsorção/efeitos dos fármacos , Animais , Bile/química , Bilirrubina/análise , Calibragem , Reagentes de Ligações Cruzadas/química , Relação Dose-Resposta a Droga , Estabilidade de Medicamentos , Luz , Estrutura Molecular , Polímeros/síntese química , Cloreto de Potássio/farmacologia , Ratos , Reprodutibilidade dos Testes , Soro/química , Cloreto de Sódio/farmacologiaRESUMO
alpha-Bilirubin is an important index to determine the liver's functions. Poly(methacrylic acid-co-ethylene glycol dimethylacrylate) (poly(MAA-co-EGDMA)) imprinted with alpha-bilirubin was proposed and shown to be able to bind alpha-bilirubin specifically. The extraction condition was also discussed. Polymers prepared by imprinting bilirubin in poly(MAA-co-EGDMA) and in poly(beta-cyclodextrin-co-EGDMA) were compared. In this work, binding specificity of molecularly imprinted polymer (MIP) toward the target template, alpha-bilirubin, is discussed. Adsorption profile of alpha-bilirubin by bilirubin-imprinted poly(MAA-co-EGDMA) was measured as a function of time, from where the equilibrium could be determined. Two hours was determined to be the proper time for adsorption. Biliverdin as a rather similar analog compound of bilirubin was chosen for comparison of binding specificity in this study. Progesterone as well as testosterone was also chosen for study because they both co-exist in serum with bilirubin and might interfere with binding capacity of imprinted poly(MAA-co-EGDMA) toward alpha-bilirubin. Specificity of this polymer for bilirubin was thus confirmed by tasks carried out in mixture solutions comprised of compounds above. It is true that biliverdin contained in the binary mixture did affect the binding capacity of bilirubin. Nevertheless, polymer's binding specificity for bilirubin was essentially sufficient for recognition of alpha-bilirubin in the presence of other compounds. How MIP identified the target template molecule, alpha-bilirubin, is also elucidated.
