Yazar "Can, Mehmet" seçeneğine göre listele
Listeleniyor 1 - 16 / 16
Sayfa Başına Sonuç
Sıralama seçenekleri
Öğe A facile one-pot synthesis of microgels and nanogels of laminarin for biomedical applications(Academic Press Inc., 2021) Can, Mehmet; Şahiner, NurettinHypothesis: Laminarin (LAM) as a nontoxic, biodegradable, and biocompatible marine polysaccharide, has been reported for its ingenious bioactivities such as antioxidant, antitumor antiapoptotic anti-inflammatory, immunomodulatory and dietary fiber activities, and distinct physicochemical structure possess a remarkably promising potential in biomaterial science. Synthesis of LAM-based microgels and bulk hydrogels have been reported in two stages: modification of LAM polysaccharide with polymerizable functional groups and subsequent crosslinking reaction. Therefore, here an easier and more effortless methods to prepare poly(laminarin) (p(LAM)) particles were tackled. Experimental: A direct and facile single step fabrication of micro/nanogels of p(LAM) for the first time by means of reverse micelle microemulsion system were illustrated. Preparation of p(LAM) particles were achieved by the well-known Oxa-Michael addition reaction mechanism using divinyl sulfone as the crosslinker. Findings: P(LAM) particles in 0.3–10 µm size range in spherical morphologies were prepared with 93 ± 7% yield and functionalized with chlorosulfonic acid (CSA) demonstrating their chemical modifiability for variety of agents e.g., targeting ligands. The bare and modified p(LAM) particles showed excellent blood compatibility with hemolytic indices of <1% and blood clotting indices higher than 90%. The reported p(LAM) particles hold great promise as natural alternative surrogates in biomedical applications including drug delivery.Öğe An amino acid, L-Glutamic acid-based metal-organic frameworks and their antibacterial, blood compatibility, biocompatibility, and sensor properties(Elsevier, 2020) Can, Mehmet; Demirci, Şahin; Sunol, Aydin K.; Şahiner, NurettinIn this study, metal-organic frameworks (MOFs) based on L-Glutamic acid (L-Glu), a natural amino acid as organic linker and Co (II), Ni (II), and Cu (II) metal ions were used in construction with 37.1 +/- 5.3%, 41.4 +/- 6.1%, 49.2 +/- 4.9% yields, respectively in ethanol under reflux. The prepared L-Glu-M (M: Co(II), Ni(II), and Cu (II)) MOFs were characterized in terms of their porosity, optical, thermal, electrical, and structural properties. Correspondingly, 102.1 m2/g, 83.7 m2/g, and 71.0 m2/g specific surface areas and 2.72 cm3/g, 0.46 cm3/g, and 0.07 cm3/g pore volumes were measured for L-Glu-based Co, Ni, and Cu MOFs. Moreover, the antimicrobial studies of L-Glu-M MOFs on Escherichia coil ATCC 8739, as gram-negative, and Staphylococcus aureus ATCC 6538 as gram-positive bacteria revealed that the highest inhibition zones with 42 +/- 2 mm and 44 +/- 1 mm were observed for L-Glu-Co MOFs. The hemolysis induction of L-Glu-M MOFs was evaluated, except L-Glu-Cu that induced 8.3 +/- 0.4% hemolysis, and the hemolytic characters of other MOF preparations were found to reside in safety margins possessing <= 4% hemolysis ratios. The blood clotting index of L-Glu-M MOFs were measured as 87.4 + 6.3% (Co(II)), 91.8 +/- 10.1% (Ni(II)), and 95.7 +/- 4.8% (Cu(II)) with neglectable interference to clotting mechanisms. Cytocompatibility of L-Glu-based MOFs were demonstrated that all MOF preparations with 25 mu g/mL concentrations maintained approximately 90% cell viabilities. Furthermore, Glu-based MOFs were demonstrated to possess sensory properties for NH3 vapor and could be employed in at least five cycles of repeated use. Therefore, L-Glu-M based MOFs can provide useful avenues in material science for a variety of biomedical and industrial applications.Öğe Carbohydrate-Derived Tailorable Interfaces: Recent Advances and Applications(Springer Singapore, 2020) Can, Mehmet; Şahiner, NurettinCarbohydrates from simple sugars to complex polysaccharides comprise a large number of biomolecules that are readily available from replenishable sources. They perform crucial biological functions through diverse interplays with proteins and lipids on the basis of specific interactions such as modulation of immune response, cellular signaling, growth, and molecular recognition events. Due to their ability to reversibly bind through hydrophobic interactions and hydrogen bonding, carbohydrates have been exploited as intriguing substrates for the design of responsive nanovehicles and therefore hold great potential for a myriad of biomedical applications. Furthermore, functional groups that exist on carbohydrates such as amino-, hydroxyl-, and acetate groups provide facile modification sites for the prepared nanostructures and render additional functionalities, e.g., carbohydrate particles with fine-tuned particle size, shape, and surface properties. In addition to these advantages, carbohydrates are biologically safe, mostly biocompatible, degradable, and have stealth characteristics along with their affinity to specific cellular elements, which enables the active targeting of the corresponding nanocarriers and the design of tailor-made, efficient, and long circulatory carrier systems. This chapter provides a brief overview of carbohydrates on the basis of structural and functional properties and highlights the cutting-edge advancements on carbohydrate-based polymeric materials in biomedical applications with a particular focus placed on the applications of polysaccharide-based micro_/nanohydrogels in nanomedicine. © Springer Nature Singapore Pte Ltd. 2021.Öğe Chemically Cross-Linked Poly(?-Cyclodextrin) Particles as Promising Drug Delivery Materials(Amer Chemical Soc, 2021) Demirci, Şahin; Khiev, Dawin; Can, Mehmet; Şahiner, Mehtap; Biswal, Manas R.; Ayyala, Ramesh S.; Şahiner, NurettinOne-pot synthesis of poly(β-cyclodextrin) (p(β-CD)) micro-/nanoparticles was accomplished using two different cross-linkers, divinyl sulfone (DVS) as p(β-CD)-1 and trimethylolpropane glycidyl ether (TMPGDE) as p(β-CD)-2. High gravimetric yields of 84 ± 4 and 62 ± 6%, respectively, were attained for p(β-CD)-1 and p(β-CD)-2 particles. The p(β-CD)-1 and p(β-CD)-2 particles had spherical shapes with 5.09 ± 0.24 and 0.60 ± 0.01 μm diameters, respectively, and exhibited good water dispersibility at physiological pH, and their isoelectric points were calculated correspondingly to be pH 1.1 and 1.2. The surface areas of p(β-CD)-1 and p(β-CD)-2 particles were determined to be 4.76 ± 0.6 and 2.18 ± 0.2 m2/g, respectively. Moreover, p(β-CD) particles were found to be biocompatible with more than 98% cell viability on human retinal pigment epithelial (ARPE-19) cells at 0.1 mg/mL concentration. Also, p(β-CD)-1 particles exhibited 52.81 ± 9.5% Fe(II) chelation capacity at 1.0 mg/mL concentration. The hemolysis and coagulation tests revealed that p(β-CD)-1 particles possessed excellent blood compatibility with a 1.18 ± 0.60% hemolysis ratio and a 92.02 ± 1.02% clotting index even at 2.0 mg/mL concentration, whereas the safety limit of p(β-CD)-2 particles for blood interactions was determined to be 0.5 mg/mL. The in vitro drug release performances of p(β-CD)-1 and p(β-CD)-2 particles for hydrophobic acyclovir and hydrophilic vancomycin model drugs at pH 7.4 PBS showed sustained releases of 2.14 ± 0.34 and 1.34 ± 0.43 mg/g acyclovir and 51.90 ± 1.09 and 61.26 ± 3.71 mg/g vancomycin within 24 h, respectively. Kinetic modeling of experimental release data revealed the best fit for drug release from p(β-CD) particles mediated by the Korsmeyer-Peppas model. ©Öğe Colloidal bioactive nanospheres prepared from natural biomolecules, catechin and L-lysine(Springer, 2022) Can, Mehmet; Şahiner, Mehtap; Şahiner, NurettinRecently, major attention has been devoted to exploring and increase biomedical applications of catechins by directly employing them as constituents of nano-vehicles. Here, (+)-catechin (CAT) was integrated with another benign biomolecule, L-Lysine (LYS) using formaldehyde (FA) via single-step Mannich condensation reaction and self-assembled supramolecular CAT-LYS networks were synthesized. By using various molar feed ratios of CAT, LYS, and FA (CAT:LYS:FA), different formulations of CAT-LYS particles were obtained as CAT-LYS-1(1:1:1), CAT-LYS-2(2:1:1), CAT-LYS-3(1:2:1), and CAT-LYS-4(1:1:2) particles. The CAT-LYS-4 particles with the highest gravimetric yield of 68.9 +/- 6.0% and 783.6 +/- 56.6 nm hydrodynamic diameter was chosen for bioactivity studies. The CAT-LYS-4 particles exhibited 190.4 +/- 1.3 mu g/mL CAT-equivalent antioxidant capacity at 1000 mu g/mL concentration with TEAC value of 0.24 +/- 0.01 mu mole Trolox-equivalent/g antioxidant activity. They showed 16.81 +/- 3.47% Fe(II) chelation capacity at 350 mu g/mL and 185.8 +/- 22.8 mu mole Fe(III) reducing power at 500 mu g/mL concentration. Moreover, the CAT-LYS-4 particles retained more than half of the alpha-glucosidase inhibition activity of CAT in particulate form. Besides, a 50-fold improvement was achieved on the hemolytic blood compatibility of CAT-LYS-4 particles upon integration of LYS into CAT backbone (4.7 +/- 1.2% at 250 mu g/mL) compared to hemolysis ratio of native CAT molecules. They did not show coagulation effects up to 500 mu g/mL concentration with > 94% clotting indices. Hence, the CAT-LYS particles with enhanced blood compatibilities and well-retained inherent bioactivities of their precursors in 3D colloidal particulate structures can serve as natural biocolloids for drug/active molecule transport applications in biomedicine.Öğe Crosslinked poly(Lactose) microgels and nanogels for biomedical applications(Academic Press Inc Elsevier Science, 2019) Can, Mehmet; Ayyala, Ramesh S.; Şahiner, NurettinHypothesis: Lactose (LAC) is a primary carbohydrate and energy source of milk has received intensive attention due to its' unique functional and nutritional properties. Many biological beneficences of LAC make it an appealing molecule to seek for designing functional interfaces. Therefore, crosslinked poly(lactose) (p(LAC)) microgel from lactose disaccharides for potential biomedical applications was pursued as biocolloids for the first time. Experiment: p(LAC) microgels prepared by chemical crosslinking with DiVinyl Sulfone (DVS) were chemically modified with ethylenediamine (EDA) to obtain amine-modified p(LAC) (p(LAC)-EDA) microgels to induce new functionalities and properties. Blood compatibilities of bare p(LAC)-EDA microgels were tested through hemolysis and blood clotting tests. Rosmarinic acid (RA) used as a model drug was loaded into p(LAC) and p(LAC)-EDA microgels to demonstrate their applicability to be used in drug loading and release applications. Findings: A facile preparation of p(LAC) microgels with high yield, 90 +/- 5% and 0.5-50 mu m size range was accomplished via water-in-oil (w/o) microemulsion crosslinking method. Upon chemical modification, the isoelectric point (IEP) from pH 1.8 for p(LAC) microgels changed to pH 7.7 for p(LAC)-EDA microgels, and the blood compatibility studies revealed that both microgels can be considered as blood compatible up to 2 mg/mL concentration, and only slight decrease in blood clotting index (BCI) of p(LAC)-EDA microgels was observed. Rosmarinic Acid (RA) was demonstrated to be released up to 4 days in phosphate buffer saline (PBS) with a linear release profile for p(LAC)-EDA microgels. (C) 2019 Elsevier Inc. All rights reserved.Öğe Dichromate and arsenate anion removal by PEI microgel, cryogel, and bulkgel(Elsevier Ltd, 2021) Kubilay, Şenol; Demirci, Şahin; Can, Mehmet; Aktaş, Nahit; Şahiner, NurettinAmong the various metal ions, chromate (Cr(VI)) and arsenate (As(V)) are the two most hazardous toxic ion species and are found in nature in the form of dichromate and arsenate anions. In this investigation, polyethyleneimine (PEI)-based hydrogels were prepared with microgel, cryogel, and bulkgel morphologies employing glycerol diglycidyl ether as a crosslinker. The prepared PEI-based hydrogels were used to remove dichromate and arsenate anions from aqueous media. PEI microgel, cryogel, and bulkgels weighing 50 mg of each adsorbed 84.7 ± 0.8, 76.5 ± 5.2, and 108.9 ± 2.4 mg.g-1 of dichromate anions and 15.9 ± 0.7, 45.4 ± 1.9, and 79.2 ± 11.6 mg.g-1 of arsenate anions in 30, 120, and 240 min, respectively. The dichromate and arsenate anions adsorption of PEI-based hydrogels were found to fit to the pseudo-second-order kinetic, and nonlinear Langmuir isotherm models, respectively with higher R2 values. The highest distribution coefficient (Kd) value of PEI-based hydrogels for dichromate adsorption was obtained on the cryogel forms of PEI as 1.89 ± 0.05. Likewise, the highest Kd value for the arsenate adsorption was calculated on PEI-based bulkgels as 0.46 ± 0.01. The thermodynamic parameters of PEI based hydrogels in the adsorption of dichromate and arsenate anions e.g., ΔG (all negative (except for the arsenate adsorption by PEI microgels), and ΔH that is around 2-10 kJ.mol-1, and ΔS what is around 0.01-0.02 kJ.mol-1. K-1 were calculated. The reusability studies showed that PEI-based hydrogels can be used for at least 5 consecutive adsorption-desorption cycles with almost 70 % anion removal efficiency after the fifth cycle.Öğe Graphene aerogels for in situ synthesis of conductive poly(Para-phenylenediamine) polymers, and their sensor application(MDPI AG, 2020) Demirci, Şahin; Can, Mehmet; Şahiner, NurettinIn this study, macroporous graphene aerogels (GAs) were synthesized by chemical reduction of graphene oxide sheets and were used as a support material for in situ synthesis of conductive poly(para-phenylenediamine) (p(p-PDA). The in situ synthesis of p(p-PDA) in GA was carried out by using a simple oxidation polymerization technique. Moreover, the prepared conductive p(p-PDA) polymers in the networks of GAs were doped with various types of acids such as hydrochloric acid (HCl), nitric acid (HNO3), sulfuric acid (H2SO4), phosphoric acid (H3PO4), respectively. The prepared GA and different acid-doped forms as GA/p(p-PDA) composites were characterized by FT-IR, TGA, and conductivity measurements. The observed FT-IR peaks at 1574 cm-1, and 1491 cm-1, for stretching deformations of quinone and benzene, respectively, confirmed the in situ synthesis of P(p-PDA) polymers within GAs. The conductivity of GAs with 2.17 x 10-4 ± 3.15 x 10-5 Scm-1 has experienced an approximately 250-fold increase to 5.16 x 10-2 ± 2.72 x 10-3 Scm-1 after in situ synthesis of p(p-PDA) polymers and with HCl doping. Conductivity values for different types of acid-doped GA/p(p-PDA) composites were compared with the bare p(p-PDA) and their undoped forms. Moreover, the changes in the conductivity of GA and GA/p(p-PDA) composites upon CO2 gas exposure were compared and their sensory potential in terms of response and sensitivity, along with reusability in CO2 detection, were evaluated. © 2020 by the authors.Öğe Graphene Aerogels for In Situ Synthesis of Conductive Poly(para-phenylenediamine) Polymers, and Their Sensor Application(Mdpi, 2020) Demirci, Şahin; Can, Mehmet; Şahiner, NurettinIn this study, macroporous graphene aerogels (GAs) were synthesized by chemical reduction of graphene oxide sheets and were used as a support material for in situ synthesis of conductive poly(para-phenylenediamine) (p(p-PDA)). The in situ synthesis of p(p-PDA) in GA was carried out by using a simple oxidation polymerization technique. Moreover, the prepared conductive p(p-PDA) polymers in the networks of GAs were doped with various types of acids such as hydrochloric acid (HCl), nitric acid (HNO3), sulfuric acid (H2SO4), phosphoric acid (H3PO4), respectively. The prepared GA and different acid-doped forms as GA/p(p-PDA) composites were characterized by FT-IR, TGA, and conductivity measurements. The observed FT-IR peaks at 1574 cm(-1), and 1491 cm(-1), for stretching deformations of quinone and benzene, respectively, confirmed the in situ synthesis of P(p-PDA) polymers within GAs. The conductivity of GAs with 2.17 x 10(-4)+/- 3.15 x 10(-5)S center dot cm(-1)has experienced an approximately 250-fold increase to 5.16 x 10(-2)+/- 2.72 x 10(-3)S center dot cm(-1)after in situ synthesis of p(p-PDA) polymers and with HCl doping. Conductivity values for different types of acid-doped GA/p(p-PDA) composites were compared with the bare p(p-PDA) and their undoped forms. Moreover, the changes in the conductivity of GA and GA/p(p-PDA) composites upon CO(2)gas exposure were compared and their sensory potential in terms of response and sensitivity, along with reusability in CO(2)detection, were evaluated.Öğe HA particles as resourceful cancer, steroidal and antibiotic drug delivery device with sustainable and multiple drug release capability(Taylor & Francis Group, LLC, 2021) Şahiner, Nurettin; Suner, Selin S.; Kurt, Saliha B.; Can, Mehmet; Ayyala, Ramesh S.Hyaluronic acid (HA) particles with divinyl sulfone (DVS) crosslinking at 10% mole ratio (HA macromolecule repeating units) were prepared and demonstrated as versatile drug carriers with sustainable and long-term release capabilities for cancer drugs, corticosteroid, and antibiotics. Two different methods were chosen in drug loading process; encapsulation for cancer drugs, 5-fluorouracil (5FU), mitomycin C (MMC), and doxorubicin (Dox), and dual drug conjugation for anti-inflammatory glucocorticoid dexamethasone (Dex) and antibiotic ciprofloxacin (Cipro) drugs, respectively. It was demonstrated that HA particles prepared during drug encapsulation were attained smaller sizes with 833 ± 46, 867 ± 50, 728 ± 41 nm for 5FU, MMC, and Dox, respectively. Bare and drug loaded HA particles were shown to be blood compatible with the highest hemolytic ratio of 3.1 ± 0.12% for HA-Dex-Cipro conjugates and fairly good blood clotting index with minimum 71.7 ± 6.0% for MMC encapsulated HA particles. Drug release studies from HA particles indicated that depending on the types of cancer drugs, it is possible to gradually release the drug in long-term up to 300 h in linear fashions with the highest release of 9.34 ± 2.25 mg/g for 5FU. Similarly, drug conjugated HA-Dex-Cipro particles were also showed linear dual drug release up to 100 h at physiological conditions, pH 7.4 and 37.5 °C.Öğe Micro and Nanogels for Biomedical Applications(2020) Can, Mehmet; Guven, Olgun; Şahiner, NurettinMicro and nano hydrogels developed from natural and synthetic polymers have garnered great deal of attention in scientific and industrial realms due to their higher surface area, degree of swelling and active material loading capacity,softness and flexibility, as well as their similarity to natural tissues. Particularly, biocompatible, non-toxic, and biodegradable micro/nano vehicles with tailor made design and functionalization facilitates their use with excellent feasibility for a variety of biomedical applications such as tissue engineering, bioimaging and drug delivery. However, these platforms requirerational design and functionalization strategies to cope with barriers of in vivo environment to pass into clinical use. Firstly,an ideal carrier should be biocompatible, and capable of evasion from immune elimination, specifically target at desiredsites and sustainably release the therapeutic cargo in response to microenvironment conditions. Despite the few setbacksin micro/nano vehicle design and several successful formulations translated to clinical use and majority of the carries areyet to achieve complete success for all biological criteria. In this review, design and functionalization strategies of micro andnanogels have been summarized. Also, the recent progress in biomedical applications of microgels and nanogels have beenoutlined with a primary focus placed on drug and biomolecule delivery applications.Öğe Modification of halloysite clay nanotubes with various alkyl halides, and their characterization, blood compatibility, biocompatibility, and genotoxicity(Elsevier Ltd, 2021) Can, Mehmet; Demirci, Şahin; Yıldırım, Yıldız; Çakır Çoban, Canan; Türk, Mustafa; Şahiner, NurettinHalloysite nanotubes (HNTs) clay were modified with alkyl halides, bromoethane (BrE), bromodecane (BrD), and bromooctadecane (BrOD), respectively. The FT-IR spectra of modified HNTs demonstrated an increase in the intensity of aliphatic –CH2 peaks at 2920 and 2850 cm−1 proportional to the number of C atoms in the modifying agent confirming the success of chemical modification with corresponding alkyl halides. Surface charge of NaOH treated HNTs, −65.7 ± 5.1 mV was increased to −37.1 ± 2.4, −40.6 ± 5.3, and −44.7 ± 1.9 mV, respectively upon chemical modification with BrE, BrD, and BrOD. The Surface area of the HNT clays, 43.2 ± 1.3 m2/g was also increased to 59.8 ± 2.7, 56.9 ± 2.1, and 47.9 ± 1.7 m2/g for BrE, BrD, and BrOD modified HNT clays, respectively. Base-activated HNT clays at 1 mg/mL concentration found to be nonhemolytic with 3.5 ± 1.2% hemolysis ratio, whereas HNT-BrOD clays were slightly exceeded hemolytic safety level with 6.6 ± 0.2% hemolysis induction. Base-activated HNT and HNT-BrOD clays were found to show antithrombogenic character with more than 100% blood clotting indexes,107.6 ± 1.8, and 106.5 ± 1.9%, respectively. Cytotoxicity studies of HNTs on L929 fibroblast cells revealed that HNTs in 12.5–200 μg/mL concentration range were shown dose-dependent cell viability, and above 50% cell viability was maintained at 200 μg/mL in all forms of HNT based clays administered.Öğe Natural Celluloses as Catalysts in Dehydrogenation of NaBH4 in Methanol for H2 Production(Amer Chemical Soc, 2020) Can, Mehmet; Demirci, Şahin; Sunol, Aydin K.; Philippidis, George; Şahiner, NurettinCellulose, the most abundant renewable biopolymer, exists in many forms, such as microgranular cellulose (MGCell), sigmacell cellulose (SCell), cellulose fibers (FCell), and alpha-cellulose (AlfaCell). Several of these cellulose forms were protonated with an amine-containing agent polyethyleneimine (PEI), and the modified celluloses (XCell-PEI+) were studied as catalysts in methanolysis of NaBH4 for hydrogen (H-2) generation. It was found that the SCell-PEI+-catalyzed reaction is the fastest one among the modified celluloses with a hydrogen generation rate of 5520 +/- 119 mL H-2/(g of catalyst x min). The activation energies of MGCell-PEI+, SCell-PEI+, FCell-PEI+, and AlfaCell-PEI+ were determined as +21.7, +23.4, +24.8, and + 21.8 kJ/mol, respectively. Reusability of catalysts was investigated, and regeneration of cellulose based catalysts after the fifth cycle could be readily achieved by HCl treatment to completely recover its activity. Therefore, PEI-modified-protonated cellulose forms constitute sustainable, re-generable, and renewable catalysts for production of H-2, an environmentally benign green energy carrier.Öğe PEI modified natural sands of Florida as catalysts for hydrogen production from sodium borohydride dehydrogenation in methanol(John Wiley and Sons Ltd, 2021) Inger, Erk; Demirci, Şahin; Can, Mehmet; Sunol, Aydin K.; Philippidis, George; Şahiner, NurettinSand samples from Tampa (T) and Panama (P) City beaches in Florida were used as catalysts for dehydrogenation of NaBH4 in methanol. T and P sand samples were sieved to [removed]500 μm sizes, and the smallest fractions resulted in faster hydrogen generation rates (HGR), 565 ± 18 and 482 ± 24 mL H2 (min.g of catalyst)−1, respectively. After various base/acid treatments, HGR values of 705 ± 51 and 690 ± 47 mL H2 (min g of catalyst)−1 for HCl-treated T and P sand samples were attained, respectively. Next, T and P sand samples were modified with polyethyleneimine (PEI) that doubled the HGR values, 1344 ± 103, and 1190 ± 87 mL H2 (min.g of catalyst)−1 and increased ~8-fold, 4408 ± 187, and 3879 ± 169 mL H2 (min g of catalyst)−1, correspondingly after protonation (PEI+). The Ea values of T and P sand samples were calculated as 24.6 and 25.9 kJ/mol, and increased to 36.1, and 36.6 kJ/mol for T-PEI+ and P-PEI+ samples, respectively.Öğe Poli(laminarin) partiküllerinin hazırlanması ve biyomedikal uygulamalarının incelenmesi(Çanakkale Onsekiz Mart Üniversitesi, Lisansüstü Eğitim Enstitüsü, 2022) Can, Mehmet; Şahiner, NurettinBu tez kapsamında yapılan çalışmalarda, Laminaria digitata ve Eisenia bicyclis kaynaklı laminarin polisakkariti (LD-LAM ve EB-LAM) kullanılarak, DVS, TMPGDE ve STPP çapraz bağlayıcıları ile mikro ve nano boyutlarda partiküller sentezlenmiştir LD-LAM ve EB-LAM partikülleri). Ters misel ortamında hazırlanan DVS ile çapraz bağlı LD-LAM partikülleri (LD-LAM-1) klorosülfonik asit ile modifiye edilmiştir (LD-LAM-2). EB-LAM molekülünden DVS, TMPGDE ve STPP çapraz bağlayıcıları ile ters misel mikroemülsiyon tekniği kullanılarak mikro/nano boyutlarda partiküller hazırlanmıştır (EB-LAM-1, -2 ve -3 partikülleri). Ayrıca EB-LAM polisakkaritinden yüzey aktif madde (sürfektan) kullanmadan nanopartikül hazırlamak için değişik oranlarda DVS ve TMPGDE çapraz bağlayıcıları ile izooktan-su emülsiyon ortamı kullanılarak sırasıyla EB-LAM-1.X ve EB-LAM-2.X partikülleri sentezlenmiştir. SEM analizleri sonucunda sürfektan içeren ortamda hazırlanan LAM partiküllerinin 0,1-15 µm arasında, sürfektan içermeyen ortamda sentezlenen partiküllerin ise 20-800 nm boyut aralığında olduğu gözlemlenmiştir. Zeta potansiyeli ölçümleri sonucunda farklı çapraz bağlayıcılar ve sentez yöntemleri ile hazırlanan LAM esaslı mikro ve nanopartiküllerinin yüzey yüklerinin -11,5±0,1 mV ile -26,3±0,5 mV arasında olduğu tespit edilmiştir. LAM esaslı partiküllerin biyomedikal malzemeler olarak kullanım potansiyellerini belirlemek için biyouyumluluk (sitotoksisite) ve kan uyumluluk (hemoliz ve kan pıhtılaşma) özellikleri araştırılmıştır. LD-LAM-1 partikülleri ve bunların modifiye edilmiş formları 2,0 mg/mL derişime kadar hemolitik ve kan pıhtılaştırıcı özellik göstermemiştir. Ayrıca, EB-LAM-1.X ve EB-LAM-2.X nanopartiküllerinin 1000 µg/mL derişime kadar L929 fibroblast hücrelerine karşı toksik etkilerinin olmadığı partiküllerin pH 7,4 PBS ortamında 120 saatte yaklaşık %50'sinin bozunduğu bulunmuştur. Bu tez kapsamında yapılan çalışmalarda, literatürde ilk kez tek basamakta LAM polisakkaritinin doğrudan çapraz bağlanması ile mikro ve nano partiküllerinin sentezi ve ayrıca bu partiküllerin kolayca modifiye edilebilirliği gösterilmiştir.Öğe Rod-like L-Aspartic acid-Cu(II) metal organic frameworks; Synthesis, characterization and biomedical properties(Elsevier B.V., 2021) Gizer, Görkem; Şahiner, Mehtap; Yıldırım, Yıldız; Demirci, Şahin; Can, Mehmet; Şahiner, NurettinL-aspartic acid (L-AA) based MOFs were prepared from acetate, chloride, nitrate, and sulfate salts of Cu(II) ions as L-AA-Cu(II)-A,-C,-N,-S, respectively with 96.7 2.4, 89.8 3.1, 92.1 1.5, 74.6 5.2 m2/g, surface areas. L-AA- Cu(II)-MOFs in the same order induced 0.43 0.25%, 0.94 0.24%, 0.91 0.40%, 1.18 0.10% hemolysis, all being <2%, and blood clotting indices of ~90% and can be considered nonhemolytic and non-coagulative at 1 μg/mL concentration. L-AA-Cu(II)-A MOFs exhibited 86.3 0.2, and 92.4 0.6% α-Glucosidase inhibitory ac- tivities at 1.0 and 10.0 μg/mL concentrations, respectively. Moreover, L-AA-Cu(II)-S MOFs had effective anti- microbial activities against E. coli (ATCC-8739), and S. aureus (ATCC-6538) with MIC values of 0.63 mg/mL and 1.25 mg/mL for C. albicans (ATCC-10231). L-AA-Cu(II) MOFs synthesized herein with hemocompatible, antimi- crobial and antidiabetic properties prompt interesting possibilities for both industrial and biomedical applications
