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Evaluation of the Accessibility of Molecules in Hydrogels Using a Scale of Spin Probes

Authors :
Iulia Matei
Ana-Maria Ariciu
Elena Irina Popescu
Sorin Mocanu
Alexandru Vincentiu Florian Neculae
Florenta Savonea
Gabriela Ionita
Source :
Gels, Vol 8, Iss 7, p 428 (2022)
Publication Year :
2022
Publisher :
MDPI AG, 2022.

Abstract

In this work, we explored by means of electron paramagnetic resonance (EPR) spectroscopy the accessibility of a series of spin probes, covering a scale of molecular weights in the range of 200–60,000 Da, in a variety of hydrogels: covalent network, ionotropic, interpenetrating polymer network (IPN) and semi-IPN. The covalent gel network consists of polyethylene or polypropylene chains linked via isocyanate groups with cyclodextrin, and the ionotropic gel is generated by alginate in the presence of Ca2+ ions, whereas semi-IPN and IPN gel networks are generated in a solution of alginate and chitosan by adding crosslinking agents, Ca2+ for alginate and glutaraldehyde for chitosan. It was observed that the size of the diffusing species determines the ability of the gel to uptake them. Low molecular weight compounds can diffuse into the gel, but when the size of the probes increases, the gel cannot uptake them. Spin-labelled Pluronic F127 cannot be encapsulated by any covalent gel, whereas spin-labelled albumin can diffuse in alginate gels and in most of the IPN networks. The EPR spectra also evidenced the specific interactions of spin probes inside hydrogels. The results suggest that EPR spectroscopy can be an alternate method to evaluate the mesh size of gel systems and to provide information on local interactions inside gels.

Details

Language :
English
ISSN :
23102861
Volume :
8
Issue :
7
Database :
Directory of Open Access Journals
Journal :
Gels
Publication Type :
Academic Journal
Accession number :
edsdoj.9745360f64640aa86d49ec072b4cfc6
Document Type :
article
Full Text :
https://doi.org/10.3390/gels8070428