Biocompatibility, biodegradability and stability are important properties for tissue matrices. At the same time, the material should promote cell attachment, proliferation, differentiation and migration. Besides polylactide, collagen or hyaluronic acid, chitosan can also be used as a biopolymer in tissue engineering. In the presented study, chitosan was functionalized with short peptide sequences as a scaffold for osteoblasts for bone tissue regeneration in order to improve the cellular properties.
HOW BIO-FUNCTIONALIZES CHITOSAN CAN CONTRIBUTE TO BONE TISSUE ENGINEERING
Bio-Functionalized Chitosan for Bone Tissue Engineering. Brun, P.; Zamuner, A.; Battocchio, C.; Cassari, L.; Todesco, M. ; Graziani, V.; Iucci, G.; Marsotto, M.; Tortora, L.; Secchi, V.; Dettin, M. International Journal of Molecular Sciences, 2021, 22, 5916. https://doi.org/ 10.3390/ijms22115916
Due to their natural biocompatibility, biodegradability and low toxicity, biopolymers such as chitosan are getting more and more attention in the field of tissue engineering. In addition, various studies have demonstrated a positive influence of chitosan on cell proliferation, adhesion and differentiation. The antimicrobial properties of chitosan are also beneficial to prevent biofilm formation on implants, for example.
To further functionalize chitosan for tissue engineering, especially in bone tissue, chitosan (Chitosan 70/1000, Heppe Medical Chitosan) was coupled with short amino acid sequences, HVP and RGD, in the described study. HVP is an adhesive peptide found in human vitronectin. It also supports osteoblast adhesion and differentiation during cell migration. RGD, on the other hand, is a tri-peptide that induces cell adhesion and migration of osteoblasts through interaction with integrin receptors.
Furthermore, the abilities of chitosan coupled with HVP (ChitHVP), chitosan coupled with RGD (ChitRGD), mixtures of functionalized chitosan and pure chitosan as scaffolds for osteoblast adhesion, growth and differentiation were investigated. In addition, the differences in antimicrobial properties were also compared.
- the bio-functionalization of chitosan increased adhesion and proliferation of human osteoblasts compared to pure chitosan
- the molecular structure of ChitHVP supported the biomimetic potential of chitosan better than ChitRGD
- only ChitHVP was able to increase the proliferation of osteoblasts - a critical process in bone tissue regeneration
- But: chitosan functionalization with biomimetic peptides decreased antimicrobial activity compared to pure chitosan
Conclusion: Overall, it was observed in this study that ChitHVP 100% was the best performing matrix for bone tissue application in comparison. However, a 1:1 mixture of ChitHVP and chitosan provided the best compromise between the antimicrobial activity of pure chitosan and the beneficial cellular properties of peptide-coupled chitosan. Link to article: https://www.mdpi.com/1422-0067/22/11/5916