Original scientific paper
https://doi.org/10.15255/KUI.2022.018
Boric Acid Modified Chitosan Scaffolds Chemically Crosslinked by Genipin
Luka Dornjak
; University of Zagreb, Faculty of Chemical Engineering and Technology, Trg Marka Marulića 19, 10 000 Zagreb, Croatia
Karla Ostojić
; University of Zagreb, Faculty of Science, Horvatovac 102a, 10 000 Zagreb, Croatia
Teodoro Klaser
; University of Zagreb, Faculty of Science, Bijenička 32 10 000 Zagreb, Croatia
Inga Urlić
orcid.org/0000-0001-7321-2192
; University of Zagreb, Faculty of Science, Horvatovac 102a, 10 000 Zagreb, Croatia
Anamarija Rogina
orcid.org/0000-0003-3967-331X
; University of Zagreb, Faculty of Chemical Engineering and Technology, Trg Marka Marulića 19, 10 000 Zagreb, Croatia
Abstract
Chitosan scaffolds are an effective biologically active material with versatile application in chemistry and medicine. Chitosan is a linear polysaccharide, a derivative of chitin, with great biocompatibility due to the possession of functional groups such as −OH and −NH2, which allow for biodegradability and antibacterial function. Chitosan has a polycation nature allowing complex formation with metal ions and many biomolecules such as DNA, proteins and lipids, while its specific structure and functional groups are responsible for antibacterial, hemostatic, and analgesic properties. To improve its angiogenic and antimicrobial potential, chitosan can be modified by boron (borate ions). The aim of this work was to prepare boric acid modified chitosan scaffolds, using boric acid as a boron precursor, as potential bioactive scaffolds for tissue regeneration. Borate ions tend to form complexes with hydroxyl groups, however, such physical interactions between boron and chitosan functional groups result in poor encapsulation efficiency. To ensure higher boron incorporation, chitosan scaffolds were cross-linked by genipin, a cross linker with lower cytotoxicity in contrast to glutaraldehyde commonly used to prepare stable chitosan-based materials. The degree of deacetylation (DD) and concentration of chitosan solution as well as the concentration of a solvent are important parameters that affect the crosslinking process. Moreover, the addition of boric acid could interfere with the crosslinking process by occupying chitosan functional groups. Here, chitosan scaffolds were modified with different concentrations of boric acid, while the concentrations of chitosan solution (1.2 w/v), genipin (2 % w/w), and acetic acid (0.5 % v/v) were kept constant. Obtained scaffolds were characterised by scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), differential scanning calorimetry (DSC), Fourier transformation infrared spectroscopy (FTIR), while cytotoxicity was evaluated as a function of materials concentration and exposure time. The results indicated successful incorporation of boron into cross-linked chitosan scaffolds with highly porous structure and low cytotoxicity.
Keywords
chitosan; boron; scaffolds; genipin; cytotoxicity
Hrčak ID:
285688
URI
Publication date:
14.11.2022.
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