Chitosan aerogel for bone regeneration

Bone tissue regeneration using artificial scaffolds on which bone cells, such as osteoblasts, can grow is a relatively new approach to repair bone fractures or bone decomposition due to disease. In the work presented, a simple method is introduced to make aerogels from chitosan. These could be suitable as scaffolds for bone cells.

 

Preparation of chitosan aerogels in ethanol without crosslinkers as scaffolds for bone-forming cells

Milica Pantić, Uroš Maver, Jan Rožanc, Boštjan Vihar, Darija Cör Andrejč, Željko Knez, Zoran Novak, Evaluation of ethanol-induced chitosan aerogels with human osteoblast cells, International Journal of Biological Macromolecules, Volume 253, Part 2, 2023, 126694, ISSN 0141-8130, https://doi.org/10.1016/j.ijbiomac.2023.126694.

Aerogels are highly porous solids used in various fields, from construction to aerospace, due to their high stability combined with low weight and excellent insulating properties. In artificial tissues, aerogels can serve as scaffolds. The pores provide enough space for the cells to grow, while the mechanically stable aerogels temporarily serve as bone substitutes. Once the bone cells have grown back sufficiently, the scaffold decomposes. The good biodegradability of chitosan makes it particularly interesting for such applications. However, highly toxic cross-linkers are usually used for the production of chitosan aerogels. The use of less harmful alternatives often leads to poorer biodegradability of chitosan, which is essential for tissue regeneration. Usually, aerogels are produced by preparing a gel in aqueous medium and subsequent drying. However, since evaporation of the liquid could damage the highly porous structure, supercritical drying with carbon dioxide is usually chosen. However, this first requires time-consuming replacement of the water with a solvent in which carbon dioxide dissolves. In the study presented here, a chitosan aerogel will be prepared in ethanol as a scaffold for bone regeneration. Preparation of the gel in ethanol eliminates both the use of toxic crosslinkers and the need for costly solvent exchange. A chitosan with a degree of deacetylation of ≥ 75% and a molecular weight of 190 to 310 kDa was used here. You can find similar products in our shop.

Results

• high stability typical for aerogels
• slightly growth-promoting for bone-forming cells (osteoblasts) in vitro
• relatively slow degradation of the aerogel when investigated in vitro
• pore diameter slightly smaller than optimal size for cell growth inexpensive, time-saving and non-hazardous method for the production of chitosan aerogels

Conclusion: Chitosan aerogels formed in ethanol may be suitable for bone regeneration, although the pore size still needs to be optimized.

Link to article: Evaluation of ethanol-induced chitosan aerogels with human osteoblast cells - ScienceDirect