In this work, an
injectable composite
hydrogel was synthesized via a unique way of crosslinking
glycol chitosan (GC) with
silica nano-particles (SiNP) through non-chemical interactions, and was then applied as a kind of
wound dressing. Gelation was achieved through the incorporation of SiNPs with the GC segments in aqueous
solution, therefore strictly confining the movement of the solubilized
polymer chains. Rheology tests showed that the
sol-gel transition and the moduli of the
hydrogel were influenced by the composition of the two components, the size of the nano-particles and the conformation of the
polymers. Using such a strategy,
tissue adhesion properties of GC were well-preserved in the GC/SiNP
hydrogel and therefore it gains gluey properties toward biological tissues as demonstrated through the adhesion of two pieces of mouse skin, obtaining a lap-shear stretching force of ca. 90 kPa. This characteristic, together with the injectability, allowed the
hydrogel to be administrated directly on the
wound site and to fill the
wound area. Meanwhile, the
hydrogel also works as a carrier of
protein and cells. The in situ encapsulation of fibroblasts enabled the promising properties of the GC/SiNP
hydrogel to be used for treating full-thickness skin defects in a mouse model, resulting in the favorable growth of hair follicles and microvessels, hence reducing the risk of
scar formation.