Molecularly imprinted polymers for enhanced impregnation and controlled release of L-tyrosine

• Type: Article in International Scientific Journal
• Date: 2018

Authors

Ferreira, VRA (Author) Other; Manuel Azenha (Author) FCUP; Carlos M Pereira (Author) FCUP; Silva, F (Author) FCUP

Journal

Title: Reactive and Functional Polymers

Vol. 131

Pages: 283-292

ISSN: 1381-5148

Publisher: Elsevier

Indexing

ISI Web of Knowledge - 8 Citations

Scopus - 9 Citations

Other information

Authenticus ID: P-00P-HQN

DOI: 10.1016/j.reactfunctpolym.2018.07.017

Abstract (EN): L-tyrosine controlled release systems, based on imprinted polymers radically polymerized in modified organic solvents (dimethyl sulfoxide and methanol) were developed. A set of copolymers synthesized with different functional monomers and the crosslinker ethylene glycol dimethylacrylate were evaluated regarding both the imprinting and controlled release features. Those prepared in modified-DMSO were mesoporous (surface area ranging 370-690 m(2)/g) but not the ones prepared in modified methanol with the exception of the imprinted polymer prepared with the monomer vinylbenzoic acid (209 m(2)/g). The swelling degree ranged 32 to 64% and appeared to be mostly dependent on the functional group employed in the synthesis of the polymers. When tested in dynamic mode a clear imprinting effect has been observed in some of the imprinted polymers. However, selectivity for L-Tyr against similar compounds could not be found in these conditions. Selectivity could be observed when carrying out the isothermal analysis, with selectivity factors up to 2.7. A few polymers exhibited also other remarkable features such as high L-Tyr load capacity (up to 253 mg L-Tyr/g) and large binding strength (up to 55 L(m)mg((1-m)))/g). Therefore, imprinted polymers capable of a selective sorption of L-Tyr upon equilibration, containing stronger binding sites for L-Tyr, appeared promising vehicles for its controlled release. In fact, the release assays with L-Tyr impregnation by adsorption, showed profiles corresponding to controlled release systems, with high yield (40-50%) and continuous release (up to at least 7 h). In addition, release mechanisms recommended for controlled release systems were deduced from kinetic data fitting to the Korsmeyer and Order 0 models.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 10