Optimal wound healing requires restoration of the damaged tissue by formation of new tissue and epithelialization. To support this process after injury, suitable wound dressings are required to prevent development of a chronic wound. In this article, we present two recently published in vivo studies dealing with the use of chitosan-silica hybrids for wound healing.
Skull Bone Regeneration Using Chitosan-Siloxane Porous Hybrids-Long-Term Implantation.
Shirosaki Y., Furuse M., Asano T., Kinoshita Y., Kuroiwa T. Pharmaceutics. 2018 Jun 8; 10(2). pii: E70. doi: 10.3390/pharmaceutics10020070.
In craniotomy, bore holes on the patient's head are required to perform neurosurgical brain surgery. In order to support the regeneration of the bone tissue after operation, the use of suitable scaffolds is important. Previous studies have shown the osteocompatibility of silica or silicates and a positive effect on bone formation. In a previous in vitro study, the authors from Japan found that a hybrid of chitosan-gamma-glycidoxypropyltrimethoxysilane (chitosan-GPTMS) induces cell migration and proliferation of human osteoblast bone marrow cells.
The present study investigates in vivo regeneration of the cranial bone after implantation of a porous hybrid of chitosan and siloxane after 2 and 3 years. Four 10 mm holes were created in 10 adult beagles and filled with hybrid material (with/without calcium or hydroxyapatite coating) or commercial bone cement as a control. The researchers used high molecular weight chitosan with a degree of deacetylation of 79%.
- Successful implantation of scaffolds, no wound infection
- Migration of cells and formation of tissue and blood vessels
- Bone formation from surrounding blood vessels, substitution of hybrid material
- Improved bone regeneration by adding calcium ions and coating with hydroyapatite
- Size reduction of burr holes or complete formation of bone tissue
- No change for holes filled with commercial bone cement 2 or 3 years after implantation
Conclusion: Chitosan-siloxane hybrids initiated the long-term regeneration of the bore holes in the skull bone, which not happend using the bone cement. The scaffolds were replaced with newly formed tissue and added calcium ions as well as coating with hydroxyapatite accelerated bone formation.
Acceleration of the healing process of full-thickness wounds using hydrophilic chitosan-silica hybrid sponge in a porcine model.
Park J.U., Jeong S.H., Song E.H., Song J., Kim H.E., Kim S. J Biomater Appl. 2018 Mar; 32(8):1011-1023. doi: 10.1177/0885328217751246. Epub 2018 Jan 22.
An optimal dressing is important for the proper care of burns, extensive skin defects or chronic wounds to prevent infection and to ensure functional integrity. The authors from Korea developed a hybrid membrane of chitosan and silica (volume ratio 90:10) and investigated their effect on wound healing using a porcine model. Nine Yorkshire pigs received 3x3 cm wounds under anesthesia, which were treated with gauze, commercial polyurethane foam (PUF), chitosan or chitosan-silica-hybrid.
- chemical coupling led to a condensed network of chitosan and silica, which was stable even when wet
- Wound healing in the porcine model was supported by the combination of chitosan and silica
- Improved wound closure by wound contraction and re-epithelialization (cell migration, neovascularization and granulation tissue formation) compared to pure chitosan or other dressings materials
Conclusion: The study found that the chitosan silica membrane interacts with the wound surface and provides the most efficient wound healing compared to the other dressing materials (including pure chitosan). The hybrid membrane induced the highest densities of collagen deposition and angiogenesis.