Nanaoparticle loaded hydrogels

Biofunctionality and biocompatibility are important when supporting or replacing tissues or organs with a polymer-based material. Hydrogels consisting of cross-linked hydrophilic polymer chains with high water content have transformed from classical materials to smart materials sensitive to stimuli in recent years. In the first part of this thesis, which set out to design smart gels, biocompatible SM-x networks with self-healing and shape memory properties were prepared based on stearyl methacrylate (SM) and vinylpyrrolidone (VP). The mole ratios were gradually changed from hydrophilic to hydrophobic units from 10% to 90% to obtain gels meeting the requirements in various potential bioapplications. Besides having a time-dependent viscoelastic character of the obtained gels, the mechanical properties of the gels were controlled by the amount of SM introduced into the reaction medium. While the gels with low SM content could not fully return to the initial modulus values, it was observed that the gels obtained at ≥60% concentrations were completely reversible due to dynamic hydrophobic interactions, which also had an effect on the self-healing behavior. In addition, it was revealed that all networks have shape memory feature by fully recalling their permanent shapes in seconds. Closely related to the angle of contact with water, the viability of human skin fibroblast cells seeded on SM x hydrogels was found to be over 82% at all x values. As a result of the findings, the wide range of properties of SM-x gel samples revealed that it has significant potential to meet the needs in various biomedical applications. In the second part of the thesis, nanocomposite hydrogels were developed by incorporating metallic nanoparticles of different geometries and structures into SM-x hydrogel networks whose properties were optimized. This is an innovative combination and structural variation of two completely different material types. Advanced functional materials have been created thanks to the fact that nanoparticles are less agglomerated and show synergistic properties against mechanical power and stimuli. Gold nanospheres (AuNS) and silver nanocubes (AgNC) particles were included in different proportions to increase smart material properties in the network structures of temperature-sensitive SM-VP hydrogels. The obtained nanocomposites have a photothermal effect in the presence of gels (Nc) nanoparticles. This prope rty made Ncs into both light- and heat-sensitive gels. The synthesized Nc gels exhibited different properties with the tests specific to the area to be applied. For example, the self-healing property under light source gave the best results in AgNc-0.08 gels, while the result showed a significant difference in AgNc-0.02 gels in terms of shape memory roperty. Thanks to the nanoparticles in the matrix, AgNc-0.08 gels showed a self healing feature under temperature compared to the SM-x version, while AgNc-0.02 gels showed a significant difference in shape memory properties. The viability of human skin fibroblast cells seeded on Nc-x hydrogels was found to be over 80% at all x values. Within the scope of this thesis, it has been shown that nanoparticle-loaded hydrogels can be potential candidates for applications in various fields, from soft robotics to 4D systems, from biomaterials to medicine, by showing changes in response to stimuli.