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Pd nanocatalyst supported on chitosan–waste oil microspheres for efficient degradation of industrial pollutants in water
(Springer Science and Business Media B.V., 2025) Karaoğlu, Kaan; Yılmaz Baran, Nuray; Özçifçi, Zehra; Akçay, Hakkı Türker; Baran, Talat
Disposal of industrial pollutants is one of the most important working topics today. Pd–doped catalysts have high efficiency in the degradation of many organic pollutants. Within the scope of this study, waste engine oil (WEO) was used as activated carbon (AC) source and then AC was encapsulated with chitosan (CS) to prepared chitosan–based microbeads (CS/WEO AC) for catalyst support. After treatment with glyoxal as cross–linker, Pd nanoparticles with spherical shape and 16.8 nm diameter were decorated on the microbeads (Pd@CS/WEO AC). Efficiency of Pd@CS/WEO AC on the reduction of 4-nitrophenol (4-NP), 4-nitro-o-phenylenediamine (4-NPDA), 2-nitroaniline (2-NA), 4-nitroaniline (4-NA) as nitroarens; methylene blue (MB), methyl orange (MO), and rhodamine B (RhB) as organic dyes; Cr(VI) and K3[Fe(CN)6] was examined in aqueous media. Developed Pd@CS/WEO AC nanocatalyst reduced nitroarenes, organic dyes, Cr(VI) and K3[Fe(CN)6] in very short times (0–130 s). Based on kinetic studies, the rate constants for Pd@CS/WEO AC–catalyzed reduction reactions of 2–NA, 4–NP, 4–NA, 4–NPDA, MO, RhB, [Fe(CN)6]3⁻, and Cr(VI) were found to be 0.018 s−1, 0.007 s−1, 0.026 s−1, 0.012 s−1, 0.021 s−1, 0.065 s−1, 0.048 s−1, and 0.042 s−1, respectively. Additionally, it was confirmed that Pd@CS/WEO AC is a long–lasting catalyst, as it was reused for five successive runs in the reduction of 4–NP. In this study, we aim to design new materials by modifying carbon–containing waste sources with biological macromolecules and investigate the possible applications of these materials to remove some pollutants from water sources.
Fabrication of smart chitosan composite beads for alleviate boron toxicity in a model plant (Lemna gibba): Characterization, toxicity assessment, and boron removal
(Elsevier Ltd, 2025) Yakar, Anıl; Türker, Onur Can; Çakmak, Emel; Yılmaz Baran, Nuray; Baran, Talat
Excessive boron (B) in aquatic ecosystems poses a significant threat to environmental health and biodiversity. In this respect, an attractive strategy should be evaluated to reduce B toxicity in the water environment and protect aquatic organisms. The study aims to reduce B-induced toxicity in a model plant, Lemna gibba, using smart chitosan-magnetic composite beads enriched with keratin, and further enhanced with boron-tolerant bacteria (Acinetobacter sp.). We tested different chitosan-magnetic composite beads for their B adsorption capacity, focusing on a specific type enriched with keratin for the first time in the literature. The effects of adding chitosan-magnetic composite beads in a test solution containing B mine effluent to alleviate B toxicity on L. gibba's growth parameters (frond number, biomass production, and EC50 value) were detailly evaluated in the experiment period. Accordingly, the chitosan-magnetic composite beads with keratin (Mag-Ch-K) demonstrated high B adsorption, with a maximum loading capacity of 2.875 mg/g at pH 7. The relative growth rate of L. gibba in a reactor containing Mag-Ch-K beads was measured to be approximately 2-fold (0.2065) higher than that of the control reactor (0.1212) without composite beads at 64 mg L−1 B concentration. More importantly, Mag-Ch-K bead significantly increased the plant's tolerance against B in the reactor matrix, as indicated by an EC50 value of 44.18 mg L−1 compared to 17.17 mg L−1 in the control. This study provides a promising approach to mitigate B toxicity in water bodies, offering a practical operation, high growth production, and preventing B pollution shock via modified bead with Acinetobacter sp. High B removal (76 %) was also achieved from reactors containing Mag-Ch-K-D through the high B-loading capacities and plant uptake. These dual benefits encourage designers to design chitosan and duckweed-based treatment systems for ecological conservation and pollution management in B-rich waters, such as B mine effluent pollution.
Development of DFO chelator-attached adsorptive membranes for selective removal of Fe3+ ions to obtain clean drinking water
(Elsevier B.V., 2025) Karakoç, Veyis; Gürkök Tan, Tuğba; Arda Küçük, Vedat; Odabaşı, Mehmet
Access to safe drinking water is one of the most significant concerns of today and foreseeable future. In order to solve this problem, scientists have been working intensively on the development of new technologies. In this study, poly(HEMA)-based porous polymeric membranes were synthesized by UV polymerization method to remove iron contamination in drinking water, which is among the main issues of water purification. The chelating agent desferroxamine (DFO) was covalently bonded to the synthesized poly(2-hydroxyethyl methacrylate-co-glycidyl methacrylate) polymeric membrane. The synthesized DFO-bound poly(HEMA-GMA) polymeric membrane was characterized by FTIR, SEM, elemental analysis, and BET surface area. The optimum removal performance for Iron (III) (Fe3+) ions from an aqueous solution of poly(HEMA-GMA)-DFO membranes was determined in a continuous flow system by varying pH, flow rate, ionic strength, and interaction times. According to the experimental results the maximum adsorption capacity of poly(HEMA-GMA)-DFO membranes for Fe3+ ions was found to be 25.7 mg Fe3+/g at pH:5.0, 1.5 ml/min flow rate, and 100 ppm concentration. The selectivity of the synthesized polymeric membrane for Fe3+ ions was determined as Fe3+>Zn2+ >Ni2+ by adsorption studies performed in the presence of Fe3+ions and Zn2+ and Ni2+ ions. Desorption studies of the membrane system were performed with 0.5 M (ethylenediaminetetraacetic acid) EDTA solution. As a result of desorption and adsorption studies that were repeated 10 times with the same polymer to determine the reuse behavior of the DFO chelator-bound membrane, it was observed that there was no significant decrease in the membrane performance for the removal of Fe3+ ions. Experimental studies revealed that, the use of synthesized poly(HEMA-GMA)-DFO membranes as adsorbents was found to be a promising method for the removal of Fe3+ ions.
Squaraine-containing hydrogels: Synthesis, drug delivery and dual phototherapies
(Elsevier B.V., 2025) Sarıgöl, Rumeysa; Algı, Melek Pamuk
To create a multipurpose therapeutic platform, Sq@poly(HEMA-co-AA) hydrogels are made of 2-hydroxyethyl methacrylate (HEMA) and acrylic acid (AA) monomers. The SK-MEL-30 skin cancer cell line was used to test the hydrogels' therapeutic effectiveness. The Sq@poly(HEMA-co-AA) hydrogels demonstrated photodynamic therapy by producing reactive oxygen species under red light and photothermal therapy by producing hyperthermia under near-infrared light. The outcomes showed the anti-cancer potential of the hydrogels against skin cancer. Furthermore, the hydrogels did not cause toxicity in the absence of light, according to biocompatibility tests conducted on the L929 cell line. Rhodamine B was efficiently released in a light-responsive manner, following exposure to a laser at 808 nm, demonstrating the hydrogels' capability for light-triggered drug delivery. These results demonstrate the intriguing potential of Sq@poly(HEMA-co-AA) hydrogels as a flexible material for controlled release of drugs and phototherapeutic applications, especially in the treatment of skin cancer.
Synthesis, characterization, and exosomal corona formation of self-assembled dipeptide nanomaterials
(Nature Research, 2025) Önal Acet, Burcu; Acet, Ömür; Wandrey, Madita; Stauber, Roland H.; Gül, Désirée; Odabaşı, Mehmet
Exosomes (Exos), also known as small extracellular vesicles, are naturally occurring nanoparticles (NPs), which are characterized by their nanometer size and negative charged in physiological environments. While it is widely accepted that proteins and biological compounds adhere to different nanomaterials (NMs), forming an outer layer known as the biomolecule corona (BC), the detailed understanding of factors contributing to BC formation as well as of its biological effects remains limited. Studies have shown that BC formation can affect the physicochemical properties of synthetic and natural NPs once contacting biological fluids. Here, we present a study investigating the novel concept of exosomal corona formation, which in contrast to the well-documented BC mainly consists of Exos/exosomal components. For this purpose, peptide-based Fmoc-Lysine (Fmoc-Lys) NMs were synthesized and characterized, and interaction studies with (cancer) cell-derived Exos were performed. Measurements of size, zeta potential, and colloidal stability indicate exosomal corona formation. Furthermore, cell viability experiments showed that the Exo-NM interaction resulted in reduced nanotoxicity profile indicating practical relevance for biological applications of these NMs. In summary, here we provide first evidence supporting the concept of exosomal corona formation around NMs that should become part of evaluating interactions at nano-bio-interfaces.
Synthesis, Characterization, and Investigation of Corona Formation of Dipeptide-Based Nanomaterials
(Multidisciplinary Digital Publishing Institute (MDPI), 2025) Dikici, Emrah; Önal Acet, Burcu; Bozdoğan, Betül; Acet, Ömür; Halets-Bui, Inessa; Shcharbin, Dzmitry; Odabaşı, Mehmet
Peptide-based nanomaterials can be easily functionalized due to their functional groups, as well as being biocompatible, stable under physiological conditions, and nontoxic. Here, diphenylalanineamide-based nanomaterials (FFANMs) were synthesized, decorated with Ca2+ ions to set the surface charge, and characterized for possible use in gene delivery and drug release studies. FFANMs were characterized by SEM, TEM, dynamic light scattering (DLS), and LC-MS/MS. Corona formation and biocompatible studies were also carried out. Some of the data obtained are as follows: FFANMs have a diameter of approximately 87.93 nm. While the zeta potentials of FFANMs and Ca2+@FFANMs were −20.1 mV and +9.3 mV, respectively, after corona formation with HSA and IgG proteins, they were shifted to −7.6 mV and −3.7 mV, respectively. For gene delivery studies, zeta potentials of Ca2+@FFANMs and DNA interactions were also studied and found to shift to −9.7 mV. Cytotoxicity and biocompatibility studies of NMs were also studied on HeLa and HT29 cell lines, and decreases of about 5% and 10% in viability at the end of 24 h and 72 h incubation times were found. We think that the results obtained from this study will assist the groups working in the relevant field. © 2024 by the authors.
Novel 4-((3-fluorobenzyl)oxy)benzohydrazide derivatives as promising anti-prostate cancer agents: Synthesis, characterization and in vitro & in silico biological activity studies
(Elsevier, 2025) Çakır, Furkan; Ateşoğlu, Şeyma; Köse, Aytekin; Ghaffari-Moghaddam, Mansour; Akbaş, Fahri; Kuran, Ebru Didem; Ulusoy Güzeldemirci, Nuray; Kılınç, Namık; Tokalı, Feyzi Sinan; Şenol, Halil
In this study, ten novel halogenated arylidenehydrazide derivatives were synthesized and characterized through 1H, 13C APT, 19F NMR, HSQC, HMBC, HRMS, and FT-IR techniques. Cytotoxic evaluations against PC3 prostate cancer and HUVEC cell lines identified compounds 8 and 14 as lead candidates, achieving IC50 values of 4.49 mu M and 4.78 mu M, respectively, with notable selectivity indexes of 12.15 and 11.78, underscoring their specificity against PC3 cells. Molecular docking studies targeting AR, VEGFR1, EGFR, and VEGFR2 suggested potential inhibitory mechanisms, with compounds 8 and 14 displaying substantial binding affinities for AR and VEGFR1. Compound 8 achieved IFD scores of -12.900 kcal/mol for AR and -10.895 kcal/mol for VEGFR1, while compound 14 recorded scores of -10.323 kcal/mol and -10.379 kcal/mol, respectively. Complementary MM-GBSA analyses revealed favorable binding energies, with compound 8 yielding Delta G values of -76.60 kcal/mol (AR) and -78.08 kcal/mol (VEGFR1) and compound 14 showing -80.67 kcal/mol (AR) and -78.61 kcal/mol (VEGFR1). MD simulations confirmed complex stability over 50 ns, indicating that compound 14 exhibited enhanced binding stability with key residues in AR and VEGFR1. ADME predictions highlighted drug-like properties, particularly for compounds 8 and 14, with high lipophilicity and favorable absorption characteristics, despite low aqueous solubility. SAR analysis emphasized the beneficial impact of halogen substitutions on potency and selectivity, establishing compounds 8 and 14 as promising candidates for further therapeutic development.
New 4-methanesulfonyloxy benzohydrazide derivatives as potential antioxidant and carbonic anhydrase I and II inhibitors: synthesis, characterization, molecular docking, dynamics & ADME studies
(Elsevier, 2025) Köse, Aytekin; Polat Köse, Leyla; Şenol, Halil; Ulusoy Güzeldemirci, Nuray
As an archetypal molecule, hydrazides have a crucial vital role in numerous applications, so hydrazide-related inhibitors, especially sulfur-enriched, are favored. In the present work, we designed, synthesized and characterized fifteen novel benzohydrazide derivatives containing 4-methanesulfonyloxy and arylidene building blocks with a four-step synthesis pathway. The inhibitory potential of the compounds was assessed using human carbonic anhydrases I and II (hCA I and II) isozymes and the results were compared to those of the standard inhibitor, acetazolamide (AZA). The antioxidant activity profiles for all compounds were also examined using various bioanalytical methods and the results were compared with the standards. The hCA I and II were the best inhibited by compounds 5f, 5g, and 5i with inhibition constants IC50 in the range 20.45-51.43 nM (AZA: IC50=218.38) for hCA I and 33.54-42.45 nM (AZA: IC50=44.39) for hCA II. Structure-activity relationships were also discussed and discovered that hCA I and II inhibition was unaffected by the presence of an electronwithdrawing or releasing group. This effectiveness was the only result of the sort of substituted group(s), which was located at the reagent. Molecular docking and dynamics simulations showed that compounds 5f, 5g, and 5i have strong and stable interactions with key amino acids and zinc ions in the active sites of enzymes, which supports their ability to block enzyme activity. In silico ADME studies predicted favorable drug-like properties and high human oral absorption for all synthesized compounds. In silico ADME studies predicted favorable drug-like properties and high human oral absorption for all synthesized compounds. These findings highlight the multifunctional potential of the synthesized benzohydrazide derivatives as hCA I and II inhibitors and antioxidants, paving the way for their further development and optimization for therapeutic applications.
Development of magnetically retrievable nanostructure Pd catalyst system supported on keratin-Schiff base and its application in catalytic and antioxidant activities
(Elsevier, 2025) Yılmaz Baran, Nuray; Çakmak, Emel; Çakmak, Yavuz Selim; Baran, Talat
Recently, the production of biomaterial supported metal nanoparticles has gained significant importance as an emerging field with numerous applications ranging from healthcare to sustainable environment due to their unique chemical, catalytic, physical, and biological properties. In this paper, we fabricated magnetically retrievable Schiff base modified-keratin supported nano-sized Pd catalyst (Pd@keratin/Fe3O4/Sch) to investigate its catalytic and antioxidant characteristics. The design procedure for Pd@keratin/Fe3O4/Sch is as follows: (1) extraction of keratin from goose feathers, (2) loading of Fe3O4 onto keratin (keratin/Fe3O4), (3) aminofunctionalization of keratin/Fe3O4 (keratin/Fe3O4/APT), (4) Schiff base modification of keratin/Fe3O4/APT (keratin/Fe3O4/Sch), and (5) preparation of the nano-structured Pd catalyst. Diverse analytical methods, bearing FT-IR, TEM, EDS, XRD, TGA, XPS, BET and FE-SEM were utilized to substantiate production of Pd nanoparticles. TEM results indicated that the formed Pd nanoparticles had an average particle size of 20 nm. The catalytic behavior of Pd@keratin/Fe3O4/Sch was then studied in the catalytic reduction of nitroaromatics (p-nitrophenol (p-NP), p-nitro- o-phenylenediamine (p-NPDA), o-nitroaniline (o-NA), p-nitroaniline (p-NA)) and organic dyes (rhodamine B (RhB), methyl orange (MO) and methylene blue (MB)). The Pd@keratin/Fe3O4/Sch successfully reduced p-NP, p-NPDA, p-NA, and o-NA rapidly with rate constants of 0.018 s-1, 0.013 s-1, 0.039 s-1, and 0.034 s- 1 , respectively. In addition, it promptly reduced MB, while it reduced MO and RhB with rate constants of 0.023 s- 1 and 0.054 s-1, respectively. The Pd@keratin/Fe3O4/Sch was readily recovered due to its magnetic nature and was reused up to six cycles. The stability of Pd@keratin/Fe3O4/Sch was confirmed through EDS and ICP analyses conducted after the reusability tests. The samples obtained after each step in the Pd@keratin/Fe3O4/Sch production were also investigated for their antioxidant activities. The order of antioxidant activity was found to decrease in the following sequence: keratin/Fe3O4, Pd@keratin/Fe3O4/Sch, keratin/Fe3O4/APT, keratin/Fe3O4/ Sch and keratin, respectively. The fabricated Pd@keratin/Fe3O4/Sch is an ideal catalyst system for remediating wastewater contaminants and biological applications with excellent catalytic and antioxidant capacity, easy recovery, and good stability.
Recent developments in subcritical water extraction of industrially important bioactive substances from plants, microorganisms, and organic wastes
(Springer, 2024) Aminzai, Mohammad Tahir; Yabalak, Erdal; Akay, Sema; Kayan, Berkant
Subcritical water extraction (SBWE) has emerged as one of the most sophisticated green extraction techniques, offering a promising approach for the extraction of bioactive compounds from diverse sources. It holds potential for environmental remediation as well as the production of useful extracts from plant materials, organic wastes, and microorganisms. This review provides a comprehensive analysis of SBWE, focusing on its application to plant materials, microorganisms, and organic wastes. SBWE refers to a process that uses liquid water at temperatures below 374 degrees C and pressures of up to 22.1 MPa, a process that maintains water in a subcritical state, enabling selective extraction of bioactive compounds. Bioactive compounds, such as phenolic compounds, terpenoids, alkaloids, and flavonoids, possess a wide range of physiological and pharmacological activities, including antibacterial, anti-inflammatory, and antioxidant properties. The review details various SBWE applications for extracting these compounds from different matrices: plant materials (seeds, leaves, roots, flowers, and fruits), microorganisms (fungi and algae), and organic wastes (peels, pomace, spent grains, and algal residues). Also, the review discusses the advantages of SBWE over traditional extraction methods, emphasizing its environmental benefits due to the use of non-toxic water as a solvent. SBWE not only enhances extraction efficiency but also reduces extraction time and energy consumption compared to conventional approaches. Besides, it explores the impact of various extraction conditions, including temperature, pressure, and the use of co-solvents, on the efficiency and yield of bioactive compounds. Additionally, it addresses the coupling of SBWE with other techniques to further improve its performance. In conclusion, SBWE stands out as a significant advancement in green extraction technology, with considerable potential for environmental remediation and the production of valuable bioactive extracts. This review highlights the current state of SBWE, its applications, and the ongoing developments in optimizing its efficiency and expanding its industrial applications.
Enhancing the performance of unitized regenerative proton exchange membrane fuel cells through microwave-synthesized chitosan based nanocomposites
(Elsevier, 2024) Yelegen, Nebi; Kümük, Berre; Balun Kayan, Didem; Baran, Talat; Kaplan, Yüksel
The membrane electrode assembly (MEA) is a core component of unitized regenerative proton exchange membrane fuel cells (UR-PEMFCs). The studies aimed to improve the cell performance and reduce the cost of the MEAs for the widespread adoption of UR-PEMFCs. The present study focuses on modifications of MEA. For this purpose, an innovative nanocomposite electrocatalyst was developed by using a carbon-based support material containing platinum nanoparticles with a diameter of approximately 20–30?nm via microwave synthesis technique. The electrocatalyst was developed by a single-step process, consist of multi-walled carbon nanotubes (MWCNT), graphitic carbon nitride (g-C3N4), chitosan (Chi), and platinum nanoparticles (MWCNT/g-C3N4/Chi/Pt nanocomposite). With the development of this support material, a relatively economical and effective electrocatalyst was obtained by large surface area and using the platinum on this surface at the nano level. The prepared catalyst was applied to commercially available membrane electrode assemblies with an active area of 100?cm2. Single-cell and triple-stack performance tests were conducted, and an increase of 17.13?% in the electrolyzer mode and 16.98?% in the fuel cell mode was achieved in single-cell performance with this applied electrocatalyst. Furthermore, an enhancement of 16.96?% in the electrolyzer mode and 16.81?% in the fuel cell mode was discerned in the UR-PEMFC stack. Beside the experimental studies, a numerical model of the modified membrane properties has been developed and validated through experimental data.
Synthesis, characterization and anticancer effect of doxorubicin-loaded dual stimuli-responsive smart nanopolymers
(Beilstein-Institut, 2024) Acet, Ömür; Kirsanov, Pavel; Acet, Burcu Önal; Halets-Bui, Inessa; Shcharbin, Dzmitry; Cömert, Seyda Ceylan; Odabaşı, Mehmet
Nanopolymers represent a significant group of delivery vehicles for hydrophobic drugs. In particular, dual stimuli-responsive smart polymer nanomaterials might be extremely useful for drug delivery and release. We analyzed the possibility to include the known antitumor drug doxorubicin (DOX), which has antimitotic and antiproliferative effects, in a nanopolymer complex. Thus, doxorubicin-loaded temperature- and pH-sensitive smart nanopolymers (DOX-SNPs) were produced. Characterizations of the synthesized nanostructures were carried out including zeta potential measurements, Fourier-transform infrared spectroscopy, and scanning electron microscopy. The loading capacity of the nanopolymers for DOX was investigated, and encapsulation and release studies were carried out. In a final step, the cytotoxicity of the DOX-nanopolymer complexes against the HeLa cancer cell line at different concentrations and incubation times was studied. The DOX release depended on temperature and pH value of the release medium, with the highest release at pH 6.0 and 41 degrees C. This effect was similar to that observed for the commercial liposomal formulation of doxorubicin Doxil. The obtained results demonstrated that smart nanopolymers can be efficiently used to create new types of doxorubicin-based drugs.
Enhanced anti-cancer efficacy of hesperidin through smart polymeric nanoparticles targeting prostate cancer
(John Wiley and Sons Inc, 2024) Yıldırım, Metin; Acet, Ömür; Önal Acet, Burcu; Karakoç, Veyis; Odabaşı, Mehmet
The rapid progress of various nanotechnology tools is currently being utilized in the management of several fatal illnesses, including cancer. Nanopolymers that encapsulate anti-cancer medication present a highly encouraging substitute to traditional therapies, primarily because of their specific targeting and accurate functionality, making them suitable for a variety of uses. Poly(2-hydroxyethyl methacrylate) (pHEMA) is a non-toxic polymer derived from the monomer HEMA, which is known for its toxicity. It can be combined with various other polymers and is associated with minimal immune response. The objective of the current investigation is to produce smart polymeric nanoparticles that are responsive to changes in pH and temperature, and capable of encapsulating hesperidin. These hesperidin-loaded poly(2-Hydroxyethyl methacrylate-N-isopropylacrylamide-Vinyl imidazole) nanoparticles, referred to as HesSNPs, aim to enhance the bioavailability of hesperidin and augment its therapeutic effectiveness in combating prostate cancer. N-isopropylacrylamide and Vinyl imidazole were employed as monomers sensitive to temperature and pH, respectively. Nanopolymers that were synthesized underwent characterization through dynamic light scattering (DLS) analyses, scanning electron microscopy (SEM), and Fourier transform infrared spectroscopy (FTIR) to analyze particle size and charge, surface morphology, and functional group determinations, respectively. HesSNPs decreased cell viability of DU-145 cells. Flow cytometry analysis revealed that apoptosis is the main mechanism underlying cell death after HesSNPs treatment.
Poly(n-isopropylacrylamıde) hydrogel incorporatıng squaraine: synthesis, drug delivery and photodynamic properties
(Muğla Sıtkı Koçman Üniversitesi Fen Bilimleri Enstitüsü, 2024) Pamuk Algı, Melek; Sarıgöl, Rumeysa
In the present work, we describe the fabrication of a thermosensitive hydrogel. To fabricate the hydrogel (Sq1@PNIPAAm), we opted to use biocompatible poly(N-isopropylacrylamide) (PNIPAM) and squaraine dye (Sq1) as the polymer and the crosslinker, respectively. It is noteworthy that Sq1@PNIPAAm can be loaded with fluorescein, and we evaluated the fluorescein release behavior of Sq1@PNIPAAm hydrogel. We noted that on demand sustainable release of fluorescein was feasible upon gradual heating of Sq1@PNIPAAm hydrogel. Furthermore, Sq1@PNIPAAm hydrogels can be used as photosensitizers pertinent to photodynamic therapy (PDT). Our results show that hydrogel possesses favorable biological safety for use in in vitro anticancer studies. In vitro experiments confirmed that Sq1@PNIPAAm hydrogels could kill over 40% of cancer cells. Overall, we have successfully shown that Sq1@PNIPAAm enabled photodynamic therapy. Moreover, fluorescein loading into Sq1@PNIPAAm was possible, and it could be used to successfully accomplish temperature-controlled on-demand release. Given the abundance of low-cost, commercially accessible monomers available for use in hydrogel synthesis, this method offers access to a wide range of functional hydrogels for use in biomedical applications.
Chemical composition and nutrient profiles of nine red macroalgae species
(BioMed Central Ltd, 2024) Yücetepe, Aysun; Kırkın, Celale; Ayar, Eda Nur; Soylukan, Caner; Dikici, Emrah; Özçelik, Beraat; Okudan, Emine Şükran
Nine red macroalgae (Amphiroa rigida, Gracilaria bursa-pastoris, Gracilaria gracilis, Grateloupia torture, Jania rubens, Laurencia obtusa, Laurencia pyramidalis, Liagora viscida, and Pterocladiella capillaries) were collected from coastal waters of Türkiye, and their proximate, fatty acid, soluble carbohydrate, and mineral profiles were investigated in the present study. According to the results, the crude protein content of the samples was between 4% and 23.8%, and four of the samples (G. turuturu, L. obtusa, L. pyramidalis, and P. capillacea) contained more than 10% protein. The crude lipid content of all the samples was below 1.6%, and the total carbohydrate content was between 38.3% and 76.9%. The macroalgae samples were generally richer in saturated fatty acids, palmitic acid being the most abundant, whereas G. gracilis had the highest content of unsaturated fatty acids (55.8%). All samples exhibited high contents of myo-inositol or glucose. Also, the samples generally had a good composition of minerals. Still, the heavy metal (i.e., Pb and Cd) content of Gracilaria gracilis was higher (59.6 µg/kg, P < 0.05) than those of the other algae samples. This study provides valuable insight into the chemical composition and fatty acid, mineral, and soluble carbohydrate profiles of Amphiroa rigida, Gracilaria bursa-pastoris, Gracilaria gracilis, Grateloupia turuturu, Jania rubens, Laurencia obtusa, Laurencia pyramidalis, Liagora viscida, and Pterocladiella capillacea from Türkiye.
Bioisosteric replacement of the carboxylic acid group in Hepatitis-C virus NS5B thumb site II inhibitors: phenylalanine derivatives
(Elsevier Masson s.r.l., 2024) Camcı, Merve; Şenol, Halil; Köse, Aytekin; Karaman Mayack, Berin; Alayoubi, Muhammed Moyasar; Karalı, Nilgün
Hepatitis C virus (HCV) is a global health concern and the NS5B RNA-dependent RNA polymerase (RdRp) of HCV is an attractive target for drug discovery due to its role in viral replication. This study focuses on NS5B thumb site II inhibitors, specifically phenylalanine derivatives, and explores bioisosteric replacement and prodrug strategies to overcome limitations associated with carboxylic acid functionality. The synthesized compounds demonstrated antiviral activity, with compound 6d showing the most potent activity with an EC50 value of 3.717 ?M. The hydroxamidine derivatives 7a-d showed EC50 values ranging from 3.9 ?M to 11.3 ?M. However, the acidic heterocyclic derivatives containing the oxadiazolone (8a-d) and oxadiazolethione (9a-d) rings did not exhibit measurable activity. A methylated heterocycle 10b showed a hint of activity at 8.09 ?M. The pivaloyloxymethyl derivatives 11a and 11b did not show antiviral activity. Further studies are warranted to fully understand the effects of these modifications and to explore additional strategies for developing novel therapeutic options for HCV.
Innovative approach against cancer: Thymoquinone-loaded PHEMA-based magnetic nanoparticles and their effects on MCF-7 breast cancer
(Elsevier B.V., 2024) Yıldırım, Metin; Acet, Ömür; Önal Acet, Burcu; Karakoç, Veyis; Odabaşı, Mehmet
Breast cancer is most common cancer among women in the World. Thymoquinone (TQ) exhibits a wide range of biological activities such as anticancer, antidiabetic, antimicrobial, analgesic, antioxidant, and anti-inflammatory effects. However, its effectiveness in cancer treatment is hindered by its poor bioavailability, attributed to its limited solubility in water. Hence, novel strategies are required to enhance the bioavailability of TQ, which possesses remarkable anticancer characteristics. The aim of this study is to prepare pHEMA-based magnetic nanoparticles carrying TQ (TQ-MNPs) to improve bioavailability, and therapeutic efficacy against breast cancer. For this purpose, TQ-MNPs were synthesized and characterized with Fourier transform infrared spectrophotometer (FTIR), scanning electron microscopy (SEM), dynamic light scattering (DLS), magnetic field using a vibrating sample magnetometer (VSM). The loading capabilities of synthesized magentic nanostructures were evaluated, and release investigations were conducted under experimental conditions that mimic the cellular environment. The findings of the studies indicated that the TQ carrying capacity of MNPs was deemed satisfactory, and the release efficiency was adequate. MNPs and TQ-MNPs showed biocompatibility against HDFa cells. TQ-MNPs showed stronger anti-proliferative activity against MCF-7 breast cancer cells compared to free TQ (p < 0.05). TQ-MNPs induced apoptosis in MCF-7 breast cancer cells.
Cross-linker engineered poly(hydroxyethyl methacrylate) hydrogel allows photodynamic and photothermal therapies and controlled drug release
(Elsevier B.V., 2024) Algı, Melek Pamuk; Sarıgöl, Rümeysa
Here, we disclose the synthesis of poly(2-hydroxyethyl methacrylate) (PHEMA) hydrogels incorporating a squaraine dye (Sq) as a chemical crosslinker, viz. Sq@PHEMA. Photothermal and photodynamic features of Sq@PHEMA hydrogels are evaluated in detail. It is noteworthy that Sq@PHEMA induces hyperthermia upon irradiation with an 808 nm laser. Furthermore, Sq@PHEMA enables the generation of reactive oxygen species (ROS) upon irradiation with red light. To our delight, Sq@PHEMA hydrogels can be used as efficient dual photosensitizers pertinent to both PDT and PTT simultaneously. Finally, the hydrogels are loaded with methotrexate (MTX) to investigate controlled drug release behavior. It is noted that Sq@PHEMA hydrogels are promising candidates as drug delivery systems since on-demand MTX release is feasible upon irradiation. In s
Luminescent carbon dots endowed with selective recognition of the carcinoid tumor biomarkers in biological fluids
(Elsevier Ltd, 2024) Algı, Fatih; Pamuk Algı, Melek; Sonkaya, Ömer; Ocakçı, Şeyma
Biomarkers are commonly used in both basic research and clinical practice as diagnostic tools. Particularly, cancer biomarkers can be applied to the early detection and diagnosis or screening the tumors. Of special note, malignant tumors can release serotonin (5-hydroxytryptamine, 5-HT). In fact, 5-HT is an excellent biomarker for carcinoid tumors since its level in blood plasma is hardly affected by other parameters. Moreover, secretion of 5-HT gives rise to elevated levels of 5-hydroxyindole-3-acetic acid (HIAA), the major metabolite of 5-HT, in urine samples of the patients with carcinoid tumors. 5-HT and HIAA are regarded as eligible biomarkers, of which concentrations in blood plasma and urine samples can be utilized for prognosis, and early diagnosis of carcinoid syndrome. Here, we unveil the facile synthesis and characterization of new Tb(III)-doped carbon dots (CDs) in the present work. Strikingly, CDs exhibited superior features for sensing 5-HT and HIAA. It is of worth to note that the Tb(III)-doped CDs induce phosphorescent response to both 5-HT and HIAA in water. Limit of detections (LODs) for 5-HT and HIAA were found to be 0.44 nM and 0.49 nM, respectively. Remarkably, these are the lowest reported values for luminescent systems to date. Moreover, CDs were utilized as chemosensors for 5-HT and HIAA in simulated blood plasma and synthetic urine samples, respectively. To this purpose, extensive luminescence measurements were performed. Accordingly, the obtained results attested that CDs were promising chemosensors for the detection of both 5-HT and HIAA in simulated blood plasma and synthetic urine samples, respectively. Last but not least, we successfully demonstrate that Tb(III)-doped CDs can be used for the detection of 5-HT in artificial cerebrospinal fluid as well as in conditions mimicking the environment within secretory vesicles where 5-HT is stored. To the best of our knowledge, this is the first example of CDs which can induce remarkable phosphorescent response to 5-HT and HIAA in biological fluids.
Highly efficient and reusable Pd nanoparticles decorated on a novel Schiff base polymer for reduction of nitroarenes and Suzuki coupling reactions
(Elsevier, 2024) Yılmaz Baran, Nuray
Environmental pollutants such as nitroarenes which released from several factories threaten flora, fauna and human life. Therefore, removal of these toxic substances from waste waters is of significance. Catalytic systems involving metal nanoparticles are effective to reduce hazardous nitroarenes and to fabricate biaryls, which are significant for pharmaceutical and natural product industries, via cross coupling reactions. The current research was conducted to produce a quick, highly efficient, simply recoverable and reusable nanocatalyst (Pd NPs@P(2- FAN)) involving Pd nanoparticles (Pd NPs) immobilized on a novel Schiff base polymer, Poly(2-((furan-2- ylmethylene)amino)-5-nitrophenol) (P(2-FAN)) for reduction of several toxic nitroarenes to harmless and useful organic molecules in water and fabrication of useful biaryls via Suzuki coupling (SC) reactions. UV–Vis, FTIR, TGA, XRD, FE-SEM and EDS techniques were used for characterizations of the synthesized materials. Then, catalytic performance of the produced Pd NPs@P(2-FAN) was examined in reduction of 2-nitroaniline, 4- nitroaniline, 4-nitrophenol, 4-nitro-o-phenylenediamine. Pd NPs@P(2-FAN) was reduced all these hazardous nitroarenes in water in very short time (between 30 and 85 s) with only 3 mg nanocatalyst using NaBH4. Moreover, Pd NPs@P(2-FAN) accomplished the fabrication of several biaryls via SC reactions using the microwave irradiation method in a solventless medium. This resulted in excellent reaction yields (99 %) with a very low catalyst amount (0.006 mol%) and a rapid reaction time (6 min). Additionally, performed reusability test results displayed that the nanocatalyst was simply recoverable and repeatedly reusable for successive six and eight cycles for reduction of nitroarenes and production of biaryls, respectively.

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