Microwave-assisted fabrication of chitosan-hydroxyapatite superporous hydrogel composites as bone scaffolds

Abstract

In this study, a novel scaffold fabrication method was developed by combining microwave irradiation and gas foaming. Chitosan superporous hydrogels (SPHs) and chitosan-hydroxyapatite (HA) superporous hydrogel composites (SPHCs) were prepared by using this method in the presence of crosslinking agent, glyoxal, and a gas-blowing agent, NaHCO3. In order to examine the effect of HA on composite structure and cellular behaviour, two types of HA particles, i.e. spherical beads in 45-80 µm diameter and powder form, were used. While rapid heating with microwave irradiation enhances gas blowing, pH increment, which is accelerated by NaHCO3 decomposition, provides better crosslinking. Thus, interconnected and well-established macroporous hydrogels/hydrogel composites were produced easily and rapidly (~1 min). Cell culture studies, which were carried out under static and dynamic conditions with MC3T3-E1 pre-osteoblastic cells, indicated that chitosan-HA bead SPHCs supported cellular proliferation and osteoblastic differentiation better than chitosan SPHs and chitosan-HA powder SPHCs. In conclusion, simultaneous gas foaming and microwave crosslinking can be evaluated for the preparation of composite scaffolds which have superior properties for bone tissue engineering.

Sustained Release of 17β-Estradiol Stimulates Osteogenic Differentiation of Adipose Tissue-Derived Mesenchymal Stem Cells on Chitosan-Hydroxyapatite Scaffolds

“…During new bone formation, as a first stage, cell proliferation was achieved and collagen type I was secreted by cells [Mygind et al, 2007;Akman et al, 2010;Beşkardeş et al, 2012]. Although the collagen type I expression levels decreased on the 21st day of culture in all scaffolds, the highest value was obtained for chitosan-HA-Np scaffolds.…”

“…On the 21st day of incubation, the ALP activity of all groups decreased. This behavior may indicate that mineralization occurred since the ALP expression was downregulated just before mineralization occurred [Beşkardeş et al, 2012].…”

“…In this study, chitosan-HA scaffolds were prepared according to the combined method of microwave irradiation and gas-foaming previously described by our group [Beşkardeş et al, 2012]. In brief, a chitosan solution of 2% (w/v) was prepared by dissolving chitosan flakes in 0.1 M acetic acid overnight by stirring.…”

“…Chitosan-HA composite scaffolds were prepared via a simultaneous gas-foaming and microwave cross-linking method previously developed by our group [Beşkardeş et al, 2012]. In brief, a chitosan solution containing HA powder and the cross-linking agent glyoxal was mixed and then the foaming agent NaHCO 3 was added.…”

Chitosan Hydrogels for Regenerative Engineering

“…The hydrogel supported osteogenic differentiation of adipose-derived mesenchymal stem cells (ADMSCs) along with neovascularization [94]. Similarly, glyoxal-crosslinked superporous chitosan and its composite hydrogels have shown to enhance bone regeneration [95]. In addition, physically crosslinked thermosensitive hydrogels have also been investigated as matrices to support bone regeneration.…”