Chitosan Gel as an In Situ–Forming Scaffold for Rat Bone Marrow Mesenchymal Stem Cells In Vivo

Abstract

We herein formulated and characterized an in situ-forming chitosan gel consisting of chitosan and glycerol phosphate (GP) disodium salt, and examined its use as an in vivo scaffold for rat bone marrow mesenchymal stem cells (rBMSCs). First, the phase transition behaviors of chitosan solutions formulated with and without GP were characterized as a function of temperature. Chitosan solutions containing > 20 wt % GP became a gel at 37 degrees C and maintained this form for 28 days in vitro and in vivo. Next, we examined whether the chitosan gel could act as a suitable biocompatible substrate for the attachment and proliferation of rBMSCs. Immunohistochemistry clearly demonstrated that rBMSCs survived well on the scaffold created by in situ-forming chitosan gel in rats. Injection of chitosan gel alone induced macrophage accumulation in the host tissue and at the edge of the chitosan, whereas injection of chitosan gel containing rBMSCs was associated with decreased macrophage accumulation, indicating immunosuppression by the transplanted rBMSCs. Our results collectively show for the first time that chitosan gel could serve as an in situ-forming gel scaffold for entrapped rBMSCs in vivo.

<i>In vivo</i> evaluation of chitosan-glycerol gel scaffolds seeded with stem cells for full-thickness mandibular bone regeneration

“…Recent studies have shown that the addition of glycerol phosphate disodium salt (GP) to CTS makes it possible to obtain a liquid solution at room temperature (RT). By means of the body temperature, this injectable solution undergoes a phase transition and becomes a gel (28,29). This behavior was observed to be related to electrostatic interactions between positively charged amine groups of CTS and phosphate anions of GP (29).…”

“…Chitosan scaffolds preparation CTS scaffolds were prepared as described elsewhere (28,29). In brief, a CTS solution was obtained by dissolving the polymer in 0.1 M acetic acid solution prepared in deionized water (DW) at a final concentration of 2.2% w/v (polymer/solvent) and sterilized by autoclave.…”

“…The surgical strategy used in this phase followed previous published protocols (28). In detail, 2 weeks after the removal of adipose tissue, surgery was performed in both groups of animals.…”

In vivo bone regeneration with injectable chitosan/hydroxyapatite/collagen composites and mesenchymal stem cells

“…A chitosan/glycerophosphate salt formulation was prepared as a biocompatible injectable vehicle for mesenchymal stem cells (MSCs) delivery [4]. Chitosan (CS) is a promising biocompatible and biodegradable natural biomaterial, while glycerophosphate salts are well-known biocompatible agents; the formulations based on chitosan combinations can be held liquid at room temperature for encapsulating living cells and turn into hydrogel in situ at body temperature [5].…”

Preparation and characterization of chitosan/β-GP membranes for guided bone regeneration

“…Interestingly, CS solutions containingβ-GP can remain in solution at low temperature and become a networked, structural solid at physiological pH and body temperature in the form of injectable, thermosensitive hydrogel [14][15][16] . CS/β-GP thermosensitive hydrogel also has biocompatiblity and biodegradability, and could stimulate the proliferation of MSCs where drugs, growth factors, and cells can be incorporated into the hydrogel before solidification in situ [17][18][19][20] .…”