Suture pullout strength and in vitro fibroblast and RAW 264.7 monocyte biocompatibility of genipin crosslinked nanofibrous chitosan mats for guided tissue regeneration
ABSTRACT Guided tissue regeneration (GTR) is a surgical technique used to direct the formation of bone in the graft space by protecting it with a barrier membrane used to exclude soft tissues during healing. Chitosan has been advocated for GTR applications because of its biocompatibility, degradability, wound healing, and osteogenic properties. In this study, electrospun chitosan membranes, crosslinked with 5 mM or 10 mM geinipin, a natural crosslinker extracted from the gardenia plant, were evaluated for suture pullout strength, crystallinity, and cytocompatibility with normal human dermal fibroblast and TIB 71(™) RAW 264.7 monocyte cells. Ultimate suture pullout strength was significantly lower (51-67%) than that of commercially available collagen membranes. Crystallinity of the electrospun chitosan mats decreased upon crosslinking by 14-17% (p = 0.013). The molecular weight of the chitosan polymer was decreased by 75% during the electrospinning process. Uncrosslinked and genipin-crosslinked chitosan mats were cytocompatible and supported fibroblast cell proliferation for 9 days. Uncrosslinked and genipin-crosslinked membranes did not activate monocytes to produce nitric oxide (NO) in vitro in the absence of lipopolysaccharide (LPS). Finally, chitosan membranes inhibited LPS-induced NO production of RAW 264.7 cells by 59-67% as compared to tissue culture plastic and collagen membrane. Improvements are needed in the tear strength of electrospun chitosan membranes for clinical application. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 100A:2890-2896, 2012.
SourceAvailable from: M. El Mehtedi
[Show abstract] [Hide abstract]
ABSTRACT: Chitosan nanofibers fabricated by electrospinning are contaminated by acidic anions from the acid spinning solution, leading to instability of the nanofibers in aqueous solutions, and the traditional fiber treatment method will also lead to the deterioration of the nanostructure. Here we demonstrate a novel approach to removing the acidic anions with full preservation of the nanofibrous structure. The as-spun nanofibers are first protected (stabilized) by reversible acylation. Second, contaminants are then eliminated by hydrolysis; finally, acylation is reversed. Chemical analysis showed the removal of the acidic anions and the graft and removal of acyl groups. Morphological analysis showed that the reversibly acylated fibers had diametersCellulose 08/2014; 21(4):2549-2556. DOI:10.1007/s10570-014-0306-3 · 3.03 Impact Factor
[Show abstract] [Hide abstract]
ABSTRACT: The present review article is intended to direct attention to the technological advances made in the 2010-2014 quinquennium for the isolation and manufacture of nanofibrillar chitin and chitosan. Otherwise called nanocrystals or whiskers, n-chitin and n-chitosan are obtained either by mechanical chitin disassembly and fibrillation optionally assisted by sonication, or by e-spinning of solutions of polysaccharides often accompanied by poly(ethylene oxide) or poly(caprolactone). The biomedical areas where n-chitin may find applications include hemostasis and wound healing, regeneration of tissues such as joints and bones, cell culture, antimicrobial agents, and dermal protection. The biomedical applications of n-chitosan include epithelial tissue regeneration, bone and dental tissue regeneration, as well as protection against bacteria, fungi and viruses. It has been found that the nano size enhances the performances of chitins and chitosans in all cases considered, with no exceptions. Biotechnological approaches will boost the applications of the said safe, eco-friendly and benign nanomaterials not only in these fields, but also for biosensors and in targeted drug delivery areas.Marine Drugs 11/2014; 12(11):5468-5502. DOI:10.3390/md12115468 · 3.51 Impact Factor