Lipit Bazlı Organik Nanoyapıların Hidrojellerin Adezyonunda Kullanılma Potansiyelinin İncelenmesi
Özet
Nanomaterials have been drawing much attention in the last years since they can be used as adhesives both in industrial and in medical applications. Nanomaterials that are metallic, lipid or polymeric can be synthesized by utilizing a variety of constituents in inorganic or organic chemistry. The nanomaterials to be used in the adhesion mechanism are required to have favorable surface properties, size distributions and strong adsorption properties on the surfaces. In the literature, nanomaterials that act as adhesives between hydrogels or tissue surfaces tend to adsorb to the network chains on the surface of the hydrogel matrix or to the protein chains on the surface of the tissue. Nanomaterials that make network or protein chains to be bridges between the hydrogel surfaces or tissue surfaces act as connectors between the gel-chains or protein-chains. In recent years, various inorganic nanomaterials such as metal oxide, silica, zinc oxide, titanium oxide nanoparticles or carbon nanotubes have come into use as adhesives on surfaces. In this study, it is aimed to use lipid organic nanomaterials as adhesive materials for first time in the literature. Lipid nanomaterials gains more attention than the other nanomaterials, especially in medical applications due to their advantages such as biocompatibility and encapsulation ability of various materials. In the first part of this study, poly(N, N-dimethylacrylamide) (PDMA) hydrogel is chosen as the commonly used model material since it can mimic physical properties of several polymeric materials and biological tissues. The hydrogel is synthesized by the using free-radical polymerization method. The swelling behavior, diffusion mechanism type and kinetics of the PDMA hydrogels were investigated under physiological conditions. At the same time, structural characterizations of PDMA hydrogels were performed by using Fourier Transform Infrared Spectroscopy (FTIR) and methods that can analyze the network structure properties. In the second part of the study, the synthesis of various organic and inorganic nanomaterials were done by using different methods in order to examine the adhesive strengths of them on different surfaces. Surface charges of nanomaterials were obtained from zeta potential measurements, and the sizes and shapes of SiO2, solid lipid nanoparticles and Aqua nanotubes are determined with Atomic Force Microscopy (AFM), Transmission Electron Microscopy (TEM) (for magnetic nanoparticles) and Dynamic Light Scattering (DLS). In the last part of the study, the effectiveness of the nanomaterial dispersions were investigated using mechanical tensile tests. For this part, the overlap surface area was determined upon the optimization studies. The effect of concentrations of Aqua nanotube dispersions on the adhesion mechanism was also investigated. Aqua nanotubes which have a diameter of 150±56 nm, length range of 4-9 μm and zeta potential of -23,7±0,2 mV exhibited a successful adhesive property in comparison with different nanomaterials. At the same time, apart from the model PDMA hydrogel, the adhesiveness of Aqua nanotubes was investigated on different material surfaces such as gelatin and calf liver tissue which was a biological tissue sample. Additionally, the use of nanomaterials at powder form were evaluated for the adhesion of liver tissue surfaces to each other. As a result, Aqua nanotubes have exhibited very strong adhesion properties on different material surfaces due to its size, favorable surface properties, negative surface charge and tubular structure. Model active ingredient encapsulation/release study of Aqua nanotubes have been evaluated in order to benefit from their internal cavities. One of The advantages of lipid nanotubes is that their inner and outer surfaces can be functionalized differently. Because of the effective role of the external surface properties in the adhesion mechanism, the encapsulation functionality of the internal surfaces has been shown to be simply by using sugar, which is a water soluble model molecule. In this study, the advantages of the system that is obtained by using Aqua nanotubes have been evaluated and adhesive property and encapsulation/release property of Aqua nanotubes were presented.
