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.

Genipin-crosslinked electrospun chitosan nanofibers: Determination of crosslinking conditions and evaluation of cytocompatibility

“…Moreover, the GP-crosslinked tissue had an impressive mechanical strength and resistance against in vitro enzymatic degradation compared to the GTA-crosslinked tissues (Sung, Huang, Huang, Tsai, & Chiu, 1998). However, although crosslinking CTS with GP has been proposed to be a better replacement for GTA to prepare CTS scaffolds with improved performance for some years (Mi, Tan, Liang, Huang, & Sung, 2001), this approach was attempted only recently for crosslinking CTS in the nanofibrous form (Austero, Donius, Wegst, & Schauer, 2012;Bavariya et al, 2014;Frohbergh et al, 2012;Norowski, Mishra, Adatrow, Haggard, & Bumgardner, 2012). With different crosslinking procedures performed, varied results were obtained with poor comparability.…”

“…To cater for tissue engineering uses, in situ crosslinking (Austero et al, 2012;Norowski et al, 2012) or post-electrospinning crosslinking treatment (Frohbergh et al, 2012) may be performed to inhibit solvability and improve mechanical properties of the as-electrospun CTS nanofibers. In this study, a post-electrospinning crosslinking with the naturally occurring crosslinker GP was proceeded to chemically crosslink the electrospun CTS nanofibers, and the commonly used crosslinker GTA was used as control.…”

“…Crosslinking is one of the most influential factors that can enhance the mechanical properties of the fibrous CTS mats (Norowski et al, 2012). Tensile properties of the electrospun CTS nanofibers crosslinked with a range of GP levels and 1% GTA were evaluated.…”

Effects of sodium acetate buffer on chitosan sponge properties andin vivodegradation in a rat intramuscular model

“…An injection volume of 50 mL and a specific refractive index increment (dn/dc) for chitosan of 0.163 mL/g were used. 22 Crystallinity X-ray diffraction (XRD) was used to characterize the crystal structure of the raw chitosan material, as well as neutral, 4.6 pH, and 5.6 pH buffered chitosan sponges. XRD patterns were determined using multiple scans from a Bruker AXS (Madison, WI) Advanced D8 X-ray diffractometer with Ka Cu radiation source at 40 kV and 40 mA over a 2h range from 5 to 40 with a step size of 0.05 and a time/step of 0.2 s.…”

Antimicrobial Activity of Minocycline-Loaded Genipin-Crosslinked Nano-Fibrous Chitosan Mats for Guided Tissue Regeneration

“…We have also demonstrated that the genipin crosslinked chitosan membranes were not cytotoxic to osteoblast or fibroblast cells, and did not cause monocyte activation. We have also shown the ability of genipin crosslinked electropun chitosan membranes to inhibit the LPS-induced release of nitric oxide (NO) from RAW 264.7 monocyte cells over a 3 day period [10]. NO expression is elevated in the periodontal and gingival tissues of patients with periodontitis and its inhibition is a potential therapeutic target [11,12].…”