engleski

The role of chitin in the biomineralization of mollusks and its integration in a PVP-CMC hydrogel scaffolds as a bone tissue regeneration biomaterial

Functionalized hydrogels have a great potential as biomaterials for bone tissue reparation. They can be used as matrices for bone tissue ingrowth, as therapeutics (by increasing disk hydrations) or/and as drug delivery systems. The challenge is to develop hydrogel scaffolds that are highly porous, but strong enough to withstand diverse mechanical strains, while mimicking the natural extracellular matrix (ECM) structure. Integration of ECM as a part of a biomaterial provides simple and efficient way to obtain scaffolds with enhanced framework structure. In this sense, marine organisms attract special attention as ECM sources (1). Their extracellular organic matrix is rich with diverse proteins and chitinous fibers. Potential of chitin is already known in the biomimetics (1, 2), but most research is conducted on the chitin isolated from arthropods, i.e. on α- chitin. In comparison, β-chitin is more suitable to serve as a biomaterial since it has better water retention possibilities, but it is also more difficult to extract from highly mineralized mollusk shells (3). Therefore, the incorporation feasibility of chitin, a bioactive, antibacterial and biodegradable material (1, 2), was examined in order to test its ability to enhance properties of the perspective mineralized PVP-CMC hydrogel scaffold (4, 5). Chitin based PVP-CMC hydrogels were prepared and characterized both as non- mineralized and mineralized form of hydrogel scaffolds. Both α-chitin (commercially bought) and β-chitin (isolated from the Sepia officinalis cuttlebone) were individually tested. Structure – function relationships of organic matrix and hydrogel scaffold structures were examined from morphological and structural perspective with the use of Fourier transmission spectroscopy (FTIR), atomic force microscopy (AFM), field emission scanning electron microscopy (FESEM) and rheometry. It was observed that at 1% strain all hydrogel scaffolds have linear trend, with highly pronounced elastic properties in comparison to viscous ones. Incorporation of β-chitin increased storage modulus of all mineralized samples, making it interesting biomaterial for further research on its utilization as a scaffold for bone tissue reparation. Acknowledgements: This research was partially supported by the Croatian Science Foundation under the projects 2504 (NanoMin) and 5055 (Bio-Mat-Form) and Ministry of Education, Youth and Sports of the Czech Republic, Program NPU I (LO1504). The work was performed according to the work plan of COST Action MP1301, New Generation Biomimetic and Customized Implants for Bone Engineering “NEWGEN”. The first author is thankful to COST Action MP1301 for providing financial support of 5th call of STSM 2016. References: 1. Čadež et al. JCIS 508 (2017) 95- 104. 2. R. Jayakumar, et al., Int. J. Mol. Sci. 12 (2011) 1876–1887. 3. I. Younes, M. Rinaudo., Mar. Drugs 13 (2015) 1133–1174. 4. R. Shah et al., Int. J. Polym. Mater. Polym. Biomater. 65 (2016) 619–628. 5. Čadež et al. AIP Conf. Proc. 1843 (2017), 050009/1-050009/7.

biomaterials ; bone tissue engineering ; hydrogels ; biomineralization ; chitin

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