Introduction. In the recent years, three-dimensional (3D) bioprinted hydrogels has been developed and tested for regenerative medicine due to their ability to mimic the anatomical structures [1,2]. Various bioinks that contain polymeric biomaterials, especially natural polymers have been prepared and tested due to their biocompatibility and favorable environment for cell attachment and proliferation. This paper presents the obtaining of 3D bioprinted scaffolds based on combinations between gelatin methacrylate (GelMa), chitosan methacrylate (CsMa), xanthan methacrylate (XMa) or dextran methacrylate (DMa). The scaffolds were obtained by extrusion bioprinting method, were characterized and compared to establish the optimal composition of the bioink and their applicability in soft tissue engineering.
Methodology. The polymers (gelatin, chitosan, xanthan, dextran) were methacrylated according to the protocol described by Camci-Unal , adding some changes to the method. Further, GelMa and the other functionalized polymeric (CsMa, XMa and DMa) solutions in PBS were mixed in different concentrations with a photoinitiator (Lap - Lithium phenyl-2,4,6-trimethylbenzoylphosphinate), homogenized, bioprinted and finally freeze-dried for characterization. Bioprinted scaffolds were characterized for their structure, morphology (SEM microscopy), swelling behavior in simulated physiological conditions, in vitro degradability, bioadhesion and in vitro citocompatibility.
Results.The polymers structure and the interactions between their chains were confirmed by FT-IR and NMR spectroscopy and indicate a 3D network with a high stability. Scanning electron microscopy indicated that GelMa reacted with CsMa, XMa and DMa, leading to 3D structures suitable for cells growth and proliferation. The data were supported by the degree of swelling and in vitro degradation tests. All materials were subjected to cytocompatibility and morphological analysis of cell culture. According to the obtained data it was obvious that the scaffolds does not have a cytotoxic effect on the biological elements.
Conclusions. The present paper aimed to obtain scaffolds by 3D printing of new bioinks based on gelatin methacrylate and chitosan methacrylate/xanthan methacrylate/dextran methacrylate. The bioprinted scaffolds have a porosity that support the diffusion of nutrients for cell development; their degradation rate can be controlled by composition and bioprinting conditions. The obtained scaffolds stimulate the cells attachment and proliferation.
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