Browsing by Subject "Biomedical materials."

Now showing 1 - 3 of 3

Open Access
Applications of biomaterials in cancer diagnosis and treatment
(2013) Gözen, Damla
Cancer remains to be a major burden of disease worldwide, despite the significant increase in the number of studies that focus on the development of novel diagnostic and treatment strategies. Recently, important part of these studies use biomaterials and their biomedical applications have been investigated extensively, due to their biocompatibility. Among these biomaterials two of them, carbon nanotubes (CNT) and polymer hydrogels have gained great importance due to their unique physical and chemical properties. The current study proposes new approaches that take advantage of these two biomaterials which could be used in the treatment and diagnosis of hepatocellular carcinoma (HCC). We first proposed the usage of CNTs as novel diagnostic tools for the determination of the aggressiveness of HCC. Two cell lines with different epithelial-to-mesenchymal (EMT) status, HUH7 and Snu182 were used and their attachment features on patterned CNT surfaces were compared. Our SEM images and MTT results revealed that the cells with epithelial phenotype (HUH7) attach and proliferate more on CNTs than the cells with mesenchymal phenotype (Snu182) which makes these surfaces promising diagnostic tools to differentiate HCC according to their aggressiveness. Secondly, polymer hydrogels with Dox release were suggested to be promising therapeutics to cure HCC. Our cell viability and cytotoxicity tests showed the inhibition of the proliferation of HCC line, SNU398 in the presence of drug-releasing hydrogels. This suggests the usage of hydrogels as drug delivery vehicles to have enhanced therapeutic efficacies in the HCC therapies.
Open Access
Design, synthesis and characterization of bioinspired nanomaterials for engineering and biomedicine
(2014) Ceylan, Hakan
Nature is an inspirational school for materials scientists. Natural selection process puts a massive pressure on biological organisms giving rise to effective strategies for fabricating materials, which generally outperform their man-made counterparts. Mimicking physical and chemical features of biological materials can greatly aid in overcoming existing design constraints of engineering and medicine. In this dissertation, a reductionist, bottom-up approach is demonstrated to recapitulate biological functionalities in fully-synthetic hybrid constructs. For material design, the potential of short, rationally-designed peptides for programmed organization into nanostructured materials is explored. The resulting nano-ordered materials exhibit multifunctional and adaptive properties, which can be tailored by the information within monomeric peptide sequences as well as the emerging properties upon their self-assembly. In light of these, design, synthesis and characterization of the prototypes of nanostructured functional materials are described in the context of regenerative medicine and biomineralization.
Open Access
Peptide nanofibers for engineering tissues and immune system
(2014) Mammadov, Rashad
Interdisciplinary work at the interface of biology and materials science is important for finding cures to complex diseases. Achievements in materials science allow us to control materials at nanoscale and design them according to specific therapeutic purposes. This includes incorporating biophysical and biochemical signals into materials to make them biologically functional. These signals are sensed by cells in normal or pathological cases and influence their decision-making process, which eventually alters cellular behavior. However, cellular environment is so complex in terms of these signals that recapitulating it with synthetic materials is unattainable considering our limited resources. Therefore, we need to distinguish those signals that are structurally simple, but at the same time biologically critical, that would drive cellular behavior to desired outcome. In this thesis, I will describe peptide nanofiber systems for tissue engineering and vaccinology applications. First system is inspired from heparan sulfate (HS) – a natural polymer in extracellular matrix – that bind to growth factors and regulate their functioning, therefore central for induction of various physiological processes. Peptide nanofibers with right composition of bioactive chemical functional groups from HS showed specific interaction with growth factors and induced endothelial cells to form blood vessels similar to natural matrices carrying HS. Considering mentioned features, these peptide nanofibers could be useful for effective regeneration of tissues. Secondly, the peptide nanofiber system carrying pathogenic DNA motives, which is an infection signal, was developed. While non-immunogenic by itself, these nanofibers shifted immune response against pathogenic DNA towards a context that is useful for fighting intracellular pathogens and cancer. Overall, this thesis demonstrates that structurally simple but appropriate biophysical and biochemical signals could be synergistic for inducing desired biological processes at the nanoscale.