Browsing by Subject "drug delivery"
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Item Open Access Item Open Access Microneedle technology as a new standpoint in agriculture: treatment and sensing(Elsevier, 2023-09) Ece, Emre; Eş, İsmail; İnci, FatihPreventing plant loss and improving their health status are essential for agricultural industry. Correspondingly, the deprivation of plants severely impacts our ecological system. As such, global efforts have been intensely made to promote the development of advanced sensing and treatment platforms to forestall plant loss. Existing technologies mainly encounter a number of challenges in providing results in a non-invasive, rapid turnaround, and affordable fashions. Accordingly, notable progressions in innovative approaches—particularly biosensing and delivery platforms, are vastly required for agriculture realm. In this regard, microneedles have emerged as a pivotal technological tool that plays multifaceted roles in biosensing and delivery systems, with attention of growing towards agriculture. Simply put, microneedles offer several advantages over conventional methods for being less invasive, rapid, and highly precise. In this review, recent advancements in microneedle technologies including their implementations in agriculture are highlighted coherently. In particular, extracting DNA from plant leaves and expressing transient genes using microneedles are elaborated in details. Microneedle-based sensing platforms for detecting essential compounds and secondary metabolites are discussed as well. Recent advances focusing the delivery of agrochemicals and nanotherapeutics via microneedles are elaborated. By this means, this review aims to bridge the existing gaps between microneedles and agriculture precisely.Item Open Access Peptide nanofibers for engineering tissues and immune system(2014) Mammadov, RashadInterdisciplinary 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.Item Open Access Slow release and delivery of antisense oligonucleotide drug by self-assembled peptide amphiphile nanofibers(2012) Bulut, SelmaAntisense oligonucleotides are short single stranded DNA sequences and they are suggested to be used for treatment of several disorders including cancer. They could enter the cell and specifically inhibit the target gene, however chemical stability, controlled release and intracellular delivery are areas that has to be focused on to increase their efficacy. Gels composed of nanofibrous peptide network have been previously suggested as carriers for controlled delivery of drugs to improve stability and to provide controlled release, but have not been used for oligonucleotide delivery. In this work, a self-assembled peptide nanofibrous system is formed by mixing a cationic peptide amphiphile (PA) with Bcl-2 antisense oligodeoxynucleotide (ODN), G3139, through electrostatic interactions. The self-assembly of PA-ODN gel was characterized by circular dichroism, rheology, atomic force microscopy (AFM) and scanning electron microscopy (SEM). AFM and SEM images revealed establishment of the nanofibrous PA-ODN network. Due to the electrostatic interactions between PA and ODN, ODN release can be controlled by changing PA and ODN concentrations in the PA-ODN gel. Cellular delivery of the ODN by PA-ODN nanofiber complex was observed by fluorescently labeled ODN molecule. Cells incubated with PA-ODN complex had enhanced cellular uptake compared to cells incubated with naked ODN. Furthermore, Bcl-2 mRNA amounts were lower in MCF-7 human breast cancer cells in the presence of PA-ODN complex compared to naked ODN and mismatch ODN evidenced by quantitative RT-PCR studies. These results suggest that PA molecules can control ODN release, enhance cellular uptake and present a novel efficient approach for gene therapy studies and oligonucleotide based drug delivery. In follow-up studies, increase in the internalization efficacy of ODN by incorporation of bioactive sequences, RGDS, to peptide sequence was also shown.