دانلود رایگان مقاله ژل آلژینات با کلسیم و چندپار کیتوزان مخلوط به عنوان کراس لینکر

ABSTRACT

Alginates are polysaccharides that are widely used in relation to their ability to form gels. Recently we reported that alginates may also form gels with chitosan oligomers as crosslinkers (Khong, Aarstad, Skjåk-Bræk, Draget, & Vårum, 2013). The purpose of the present study was to characterize alginate gels crosslinked with calcium and chitosan oligomers. Using two different alginates of similar molecular weights but different chemical composition, i.e. guluronic acid content of 46 and 68%, we found that both alginates could form homogeneous gels with calcium and chitosan oligomers separately and without syneresis. Systematic combinations of calcium and chitosan oligomers as crosslinkers were tested, showing that up to 50% of the calcium could be substituted with chitosan oligomers without reduction in gel strength or increased syneresis for the alginate with the lowest guluronic acid content. Furthermore, the kinetics of the combined gels were different from pure calcium alginate gels.

4. Conclusions

Homogeneous alginate gels crosslinked with both calcium and chitosan oligomers can be prepared by internal gelling using a proton donor to simultaneously release calcium ions and protonate chitosan oligomers. Up to 50% of the calcium in alginate gels could be substituted with chitosan oligomers without loss in gel strength or change in syneresis, which means that the new gels have potential new applications for e.g. immobilization of calcium-sensitive cells.