Publications by authors named "Didem Karaman"

Toxoplasma gondii is an obligate intracellular parasite that can infect a variety of mammals including humans and causes toxoplasmosis. Unfortunately, a protective and safe vaccine against toxoplasmosis hasn't been developed yet. In this study, we developed a DNA vaccine encoding the SRS13 protein and immunized BALB/c mice thrice with pVAX1-SRS13 through the intramuscular route (IM) or intradermally using an electroporation device (ID + EP).

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Nanofibers (NF) and nanoparticles are attractive for drug delivery to improve the drug bioavailability and administration. Easy manipulation of NF as macroscopic bulk material give rise to potential usages as implantable local drug delivery systems (LLDS) to overcome the failures of systemic drug delivery systems such as unmet personalized needs, side effects, suboptimal dosage. In this study, poly(ethylene glycol) polyethyleneimine (mPEG:PEI) copolymer blended poly-caprolactone NFs, NFaccommodating mesoporous silica nanoparticles (MSN) as the implantable LLDS was achieved by employing spin coating and cold atmospheric plasma (CAP) as the post-process for accommodation on NF.

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The recalcitrant nature of biofilms makes biofilm-associated infections difficult to treat in modern medicine. Biofilms have a high vulnerability to antibiotics and a limited repertoire of antibiotics could act on matured biofilms. This issue has resulted in a gradual paradigm shift in drug discovery and therapy, with anti-biofilm compounds being sought alongside new drug carriers.

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Due to its modular and flexible design options, mesoporous silica provides ample opportunities when developing new strategies for combinatory antibacterial treatments. In this study, antibacterial ceria (CeO) nanoparticles (NP) were used as core material, and were further coated with a mesoporous silica shell (mSiO) to obtain a core@shell structured nanocomposite (CeO@mSiO). The porous silica shell was utilized as drug reservoir, whereby CeO@mSiO was loaded with the antimicrobial agent capsaicin (CeO@mSiO/Cap).

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Public awareness of infectious diseases has increased in recent months, not only due to the current COVID-19 outbreak but also because of antimicrobial resistance (AMR) being declared a top-10 global health threat by the World Health Organization (WHO) in 2019. These global issues have spiked the realization that new and more efficient methods and approaches are urgently required to efficiently combat and overcome the failures in the diagnosis and therapy of infectious disease. This holds true not only for current diseases, but we should also have enough readiness to fight the unforeseen diseases so as to avoid future pandemics.

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Integrating multiple materials with different functionalities in a single nanostructure enables advances in many scientific and technological applications. However, such highly sophisticated nanomaterials usually require complex synthesis processes that complicate their preparation in a sustainable and industrially feasible manner. Herein, we designed a simple general method to grow a mesoporous silica shell onto any combination of hydrophilic nanoparticle cores.

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Glioblastoma (GB) is the most frequent malignant tumor originating from the central nervous system. Despite breakthroughs in treatment modalities for other cancer types, GB remains largely irremediable due to the high degree of intratumoral heterogeneity, infiltrative growth, and intrinsic resistance towards multiple treatments. A sub-population of GB cells, glioblastoma stem cells (GSCs), act as a reservoir of cancer-initiating cells and consequently, constitute a significant challenge for successful therapy.

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Polymicrobial biofilms are major complications of various chronic infections. Therefore, in vitro biorelevant polymicrobial biofilm models are essential tools for medical studies. This study presents an in vitro model for dual species biofilm of Pseudomonas aeruginosa and Staphylococcus aureus developed on cell-derived matrices (CDMs), in order to simulate the microenvironment of in vivo biofilms.

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This review details the antimicrobial applications of inorganic nanomaterials of mostly metallic form, and the augmentation of activity by surface conjugation of peptide ligands. The review is subdivided into three main sections, of which the first describes the antimicrobial activity of inorganic nanomaterials against gram-positive, gram-negative and multidrug-resistant bacterial strains. The second section highlights the range of antimicrobial peptides and the drug resistance strategies employed by bacterial species to counter lethality.

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Orodispersible films (ODF) are immediately dissolving/disintegrating intraoral dosage forms, presented as substitutes of conventional tablets or capsules to ease problems associated with swallowing. Efforts have been made to be able to exploit ODFs as dosage forms for poorly soluble drugs. In the last two decades, mesoporous silica nanoparticles (MSNs) have been extensively used in drug delivery applications to overcome solubility problems of drugs.

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In this study, a new approach to the implementation of optical imaging of fluorescent nanoparticles in a biological medium using artificial neural networks is proposed. The studies were carried out using new synthesized nanocomposites - nanometer graphene oxides, covered by the poly(ethylene imine)-poly(ethylene glycol) copolymer and by the folic acid. We present an example of a successful solution of the problem of monitoring the removal of nanocomposites based on nGO and their components with urine using fluorescent spectroscopy and artificial neural networks.

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Recent progress in the development of silica- and silicon-based multimodality imaging nanoprobes has advanced their use in image-guided drug delivery, and the development of novel systems for nanotheranostic and diagnostic applications. As biocompatible and flexibly tunable materials, silica and silicon provide excellent platforms with high clinical potential in nanotheranostic and diagnostic probes with well-defined morphology and surface chemistry, yielding multifunctional properties. In vivo imaging is of great value in the exploration of methods for improving site-specific nanotherapeutic delivery by silica- and silicon-based drug-delivery systems.

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The interaction between disulfiram (Antabus) and silica was studied experimentally by adsorption from apolar solvent onto highly porous silica material (Santa Barbara amorphous material-3) with large surface area. The adsorption isotherm was fitted to the Langmuir model by accounting 2 different affinities contributing to the overall behavior, which were attributed to 2 different types of silanol groups (i.e.

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Mesoporous silica nanoparticles (MSNs) have shown great potential in improving drug delivery of poorly water soluble (BCS class II, IV) and poorly permeable (BCS class III, IV) drugs, as well as facilitating successful delivery of unstable compounds. The nanoparticle technology would allow improved treatment by reducing adverse reactions of currently approved drugs and possibly reintroducing previously discarded compounds from the drug development pipeline. This study aims to highlight important aspects in mesoporous silica nanoparticle (MSN) ink formulation development for digital inkjet printing technology and to advice on choosing a method (2D/3D) for nanoparticle print deposit characterization.

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To overcome endo/lysosomal restriction as well as to increase the clinical availability of nanomedicine, we report on a NIR stimuli-responsive nanoplatform based on mesoporous silica nanoparticles tethered with lipid bilayers (MSN@tLB) for chemotherapy and photodynamic dual-modality therapy. In this nanosystem, a hydrophilic drug molecule zoledronic acid (ZOL) was first incorporated into the MSN core with modifications of hyperbranched polyethylenimine (PEI). To prevent the leakage of the payload, the LB shell was covalently tethered onto the MSN core via the PEI cushion which can greatly enhance the stability of the LB.

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Approaches to increase the efficiency in developing drugs and diagnostics tools, including new drug delivery and diagnostic technologies, are needed for improved diagnosis and treatment of major diseases and health problems such as cancer, inflammatory diseases, chronic wounds, and antibiotic resistance. Development within several areas of research ranging from computational sciences, material sciences, bioengineering to biomedical sciences and bioimaging is needed to realize innovative drug development and diagnostic (DDD) approaches. Here, an overview of recent progresses within key areas that can provide customizable solutions to improve processes and the approaches taken within DDD is provided.

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Silicon-based mesoporous nanoparticles have been extensively studied to meet the challenges in the drug delivery. Functionality of these nanoparticles depends on their properties which are often changing as a function of particle size and surrounding medium. Widely used characterization methods, dynamic light scattering (DLS), and transmission electron microscope (TEM) have both their weaknesses.

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Drug delivery into the brain is impeded by the blood-brain-barrier (BBB) that filters out the vast majority of drugs after systemic administration. In this work, we assessed the transport, uptake and cytotoxicity of promising drug nanocarriers, mesoporous silica nanoparticles (MSNs), in in vitro models of the BBB. RBE4 rat brain endothelial cells and Madin-Darby canine kidney epithelial cells, strain II, were used as BBB models.

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In this study, we have investigated the contrast enhancement of Gd(iii) incorporated nanoparticle-based contrast agents (CA) by the modulation of the synthesis and structural parameters of the mesoporous silica nanoparticle (MSN) matrix. In the optimisation process, the structure of the MSN matrix, post-synthesis treatment protocols, as well as the source and incorporation routes of paramagnetic gadolinium centers were considered, with the aim to shorten the T weighted relaxation time. After preliminary evaluation of the prepared MSNs as nanoparticulate T/positive contrast agents based on relaxivity, the structure of the MSN matrix was affirmed as the most decisive property to enhance the r relaxivity value, alongside the incorporation route of paramagnetic Gd(iii) centers.

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Targeted delivery of drugs is required to efficiently treat intestinal diseases such as colon cancer and inflammation. Nanoparticles could overcome challenges in oral administration caused by drug degradation at low pH and poor permeability through mucus layers, and offer targeted delivery to diseased cells in order to avoid adverse effects. Here, we demonstrate that functionalization of mesoporous silica nanoparticles (MSNs) by polymeric surface grafts facilitates transport through the mucosal barrier and enhances cellular internalization.

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Purpose: Silica nanoparticles (SNPs) are increasingly used as drug delivery systems (DDS) and for biomedical imaging. Therapeutic and diagnostic agents can be incorporated into the silica matrix to improve the stability and dissolution of drug substances in biological systems. However, the safety of SNPs as drug carriers remains controversial.

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