Highlighted articles published by İTÜ Chemistry Department in early 2024

A novel study on silane's impact on surface and mechanical properties of polyurethane coating

Prof. Dr. Nilgün Kızılcan and her team showcase groundbreaking advancements in polyurethane coatings in a high-impact study published in 'Advanced Materials Interfaces' (Q1, IF: 6.38). Their research, featured on the back cover, delves into the transformative effects of varying the silane additive ratio, specifically TMSCH, on the surface and mechanical properties of coatings. This pioneering work not only enhances scratch resistance and hydrophobic traits but also sets new standards for coating applications in household appliances and beyond.

Continuous development in the formulation and processing techniques of polyurethane (PU) coatings improves an aesthetic appearance as well as protection against environmental factors. In this study, the formulation of PU coating with polyethylene glycol 600 (PEG600), isophorone diisocyanate (IPDI), and trimethoxysilylpropylcarbamoyloxyhexane (TMSCH) silane-based additive is optimized to obtain high scratch-resistant coating. An addition of 43.1 wt.% TMSCH in PU formulation resulted in a significant improvement in the scratch resistance and wettability properties compared with pure PU film. The homogenously prepared micron-thick coatings are characterized using scanning electron microscopy analysis and Fourier transform infrared spectroscopy. The results confirm the presence of silane additives in the PU coating matrix. The mechanical properties improved due to the increased crosslinking networks via the formation of urethane bonds by increasing the TMSCH in PU formulation. Prepared PU coating showed combined features of transparency, hydrophobicity, scratch resistance, and mechanical strength that make it a promising candidate for household appliances.

To access full article, https://onlinelibrary.wiley.com/doi/10.1002/admi.202300944

Biodegradable, Fluorescent PBAE: A Dual-Functional Photosensitizer for Targeted Cancer Therapy and Imaging

Recently, Kahveci and his research group have been developed, a water-dispersible, biodegradable and fluorescent poly(β-amino ester) (PBAE) based photosensitizer (PS) for efficient photodynamic therapy (PDT) and imaging. The polymeric PSs demonstrated significant anti-cancer potential as evaluated via reactive oxygen species generation, photocytotoxicity, colony formation and cell invasion assay. 

This paper presents the development of a biodegradable, highly water-dispersible, and fluorescent poly(β-amino ester) (PBAE) designed as an efficient photosensitizer (PS) for photodynamic therapy (PDT) and imaging. Synthesized through aza-Michael addition-based poly-condensation polymerization, the PBAEs feature amine end groups and are end-capped with folic acid to enhance cancer-cell-targeting efficiency. These polymers form globular nano-sized particles for passive tumor targeting and demonstrate significant anti-cancer activity against U87-MG brain tumor cells and HeLa cervical tumor cells without significant cytotoxicity to non-cancer cells. The anti-cancer mechanism involves singlet oxygen and reactive oxygen species (ROS) generation upon red light irradiation, which reduces colony formation and prevents cancer cell invasion. Additionally, these polymers are highly effective in cancer cell imaging, making them a promising dual-functional tool for cancer treatment and diagnostics.

To access full article, https://doi.org/10.1039/D4PY00318G

Eco-Friendly PLA Enhanced with Caffeic Acid for Antioxidant and Antimicrobial Applications

Kahveci and his research group have been successfully grafted caffeic acid onto PLA-b-PHEMA polymer. Grafted copolymer exhibited antimicrobial and antioxidant properties. Films were prepared by combining commercial PLA with different proportions of PLA-b-PHEMA-g-CA using a solvent casting method. Both grafted copolymer and films exhibited antioxidant property and antimicrobial effect against S. aureus and E. coli, showcasing potential applications in sustainable materials. 

Kahveci and his research group underscores the importance of enhancing poly(lactic acid) (PLA), an eco-friendly alternative to petroleum-based plastics derived from renewable sources like corn starch and sugarcane. While PLA lacks inherent functional groups, limiting its applications, this study addresses this by grafting a bioactive compound, caffeic acid, onto a poly(D,L-lactide)-b-poly(2-hydroxyethyl methacrylate) block copolymer (PLA-b-PHEMA). The resulting copolymer, PLA-b-PHEMA-g-CA, exhibits significant antioxidant and antimicrobial properties against S. aureus and E. coli, as confirmed by various characterization techniques. By blending this grafted copolymer with commercial PLA to produce films, the study demonstrates the potential for creating sustainable materials with enhanced functional properties, paving the way for innovative applications across diverse fields.

To access full article, https://doi.org/10.1016/j.eurpolymj.2024.113056

Innovative pH-Responsive Delivery System to Combat Antimicrobial Resistance

Kahveci and his research group have been developed a pH-responsive antibiotic delivery system based on pH-responsive poly(β-amino ester) (PBAE) and enzyme responsive hyaluronic acid (HA). The polymeric nanocomplexes were obtained via electrostatic complexation of PBAE and HA in the presence of a model antibiotics, colistin and vancomycin. The nanocomplexes released the drugs more at pH 5.5 compared to pH 7.4. Antibacterial activity of the system was evaluated on various bacteria. The nanocomplex loaded with the antibiotics exhibited significantly greater efficacy against E. coli and S. aureus.

The World Health Organization (WHO) identifies antimicrobial resistance (AMR) as a severe global threat to health, food security, and development. Efforts to combat AMR include educating individuals, implementing new policies, and developing novel antimicrobials and materials for effective delivery. Among these, innovative drug delivery systems that enable local and on-demand antibiotic release are particularly promising. This study introduces a pH-responsive antibiotic delivery system using poly(β-amino ester) (PBAE) and enzyme-responsive hyaluronic acid (HA). These polymeric nanocomplexes, formed through electrostatic complexation with model antibiotics colistin and vancomycin, exhibit size ranges of 131–730 nm at pH 7.4, which increase significantly at pH 5.5. The drug release performance, tested with FITC-labeled antibiotics, showed enhanced release at the acidic pH of 5.5. Antibacterial activity assays demonstrated that these nanocomplexes are significantly more effective against E. coli and S. aureus, highlighting their potential as a robust strategy for combating AMR through targeted and efficient antibiotic delivery.

To access full article, https://doi.org/10.1016/j.ijbiomac.2023.129060

A Novel Use of Thienothiophene (TT) and Single-Wall Carbon Nanotube (SWCNT) as High-Performance Supercapacitor

Prof. Turan Öztürk and coworkers’ report, for the first time, use of thienothiophene (TT) and single wall carbon nanotube (SWCNT) based free-standing and flexible hybrid material (TT-TPA-SWCNT) as a high-performance supercapacitor. The synthesized TT derivative, TT-TPA, was directly attached to SWCNT through non-covalent interactions to obtain the TT based SWCNT hybrid, TT-TPA-SWCNT as a flexible film. The TT-TPA-SWCNT supercapacitor displayed a high specific capacitance of 83.2 F·g^-1 at 5 mV·s^-1, a maximum power density of 3000 W·kg^-1 and an excellent retention capacity of 110% up to 7000 charge/discharge cycling stability. 

Prof. Turan Özturk and coworkers’ paper introduces a novel hybrid material, thienothiophene (TT) and single-walled carbon nanotube (SWCNT) composite (TT-TPA-SWCNT), as a high-performance supercapacitor. This flexible and free-standing electrode demonstrates an impressive energy storage capacity of 83.2 F g⁻¹ at a 5 mV s⁻¹ scan rate, exceptional cyclic stability with 110% retention after 7000 cycles, and a wide power density range of 100 to 3000 W·kg⁻¹. Advanced characterization methods reveal its promising structure, positioning TT-TPA-SWCNT as a significant advancement in energy storage systems for diverse applications.

To access full article, https://pubs.acs.org/doi/full/10.1021/acsaem.3c02737.

Prof. Turan Öztürk's Team Unveils Dual-Channel TTM Fluorescent Probe for Highly Sensitive ClO− Detection

Prof. Turan Öztürk and coworkers report, a novel TTM fluorescent probe bearing fluorobenzene substituted thienothiophene, thiophene and malononitrile units for highly sensitive and selective detection of ClO. To literature, this report is one of the rare examples of a dual-channel (optical and electrochemical) probe with a turn-on mechanism.

This paper highlights the development of a novel probe, TTM, which combines thienothiophene and malononitrile units for the exceptionally selective and sensitive detection of hypochlorite (ClO⁻). As ClO⁻ is a crucial reactive oxygen species in biological systems, with roles in both natural defense and potential oxidative damage when in excess, the need for a reliable detection method is paramount. TTM addresses this need with a rapid “turn-on” fluorescence response in under 30 seconds, naked-eye colorimetric detection, and voltammetric read-out with an anodic scan. The probe's low detection limit and applicability in real water samples and living cells make it a significant advancement. This study is notable for being one of the few examples utilizing a small thienothiophene-based molecule for both optical and electrochemical detection of ClO⁻ in aqueous media.

To access full article, https://www.sciencedirect.com/science/article/pii/S0039914023012961

A Novel Investigation into the Impact of Microplastics on Bacterial Activity in Seawater Under the Influence of Climate Change

Prof. Dr. Aslı BAYSAL and her colleagues’ study reveals the significant impact of microplastics (MPs) on bacterial activity and biofilm formation in seawater, especially under varying temperature conditions influenced by climate change. It highlights how temperature variations can alter bacterial responses, oxidative characteristics, and biochemical reactions, shedding light on the complex interactions between MPs and marine bacteria. The differential responses of antioxidant systems in bacteria, the enhanced biofilm formation due to MP deformation, and the strong links between functional groups on MPs and bacterial responses underscore the ecological risks posed by MPs. Moreover, the research emphasizes the necessity for further investigations into the effects of environmental conditions on MP-microbe interactions, particularly in the context of global warming and extreme weather events. Understanding these dynamics is vital for developing effective strategies to mitigate the environmental impact of MPs and protect marine ecosystems.

Temperature changes due to climate change and microplastic contamination are worldwide concerns, creating various problems in the marine environment. The article “Culture dependent analysis of bacterial activity, biofilm-formation and oxidative stress of seawater with the contamination of microplastics under climate change consideration” corresponded by Prof. Dr. Aslı BAYSAL from Chemistry Department was published in the “SCIENCE OF THE TOTAL ENVIRONMENT” (Q1, IF: 10.94) aims to the impact of different temperatures of seawater exposed to different types of plastic materials on culture dependent bacterial responses and oxidative characteristics. 

To access full article, https://www.sciencedirect.com/science/article/pii/S0048969724012427.

A groundbreaking research on oxidative stress, biofilm-formation and activity effects of microplastic-treated sediments on P. aeruginosa cells

The study which presented by Prof. Dr. Aslı BAYSAL and her colleagues addresses the globally emerging problems of microplastic (MP) contamination and temperature changes, highlighting their multifaceted impacts on environmental media. Unlike previous research focusing primarily on the direct effects of MPs, this study delves into the broader ecological implications, including the degradation, sorption, and subsequent changes in surrounding media. By examining MPs from various products and their interaction with anthropogenically affected sediments under different temperature conditions, the study reveals significantly different bacterial responses and biofilm formation. Notably, MPs from PET water bottles elicited higher metabolic responses and oxidative stress in sediments, underscoring the influence of sediment type on MP behavior. The research also demonstrates how climate change-induced temperature fluctuations can exacerbate MP contamination effects, leading to adaptive bacterial responses and enhanced biofilm formation. These findings emphasize the necessity for further investigation into the oxidative potential of different environmental media and the adaptive responses of microorganisms, including extremophiles, to MP contamination. Such comprehensive examinations are crucial for understanding and mitigating the environmental impact of MPs on marine and sediment ecosystems.

Climate change and plastic pollution are the big environmental problems that the environment and humanity have faced in the past and will face in many decades to come. Sediments are affected by many pollutants and conditions, and the behaviors of microorganisms in environment may be influenced due to changes in sediments. The article “Oxidative stress, biofilm-formation and activity responses of P. aeruginosa to microplastic-treated sediments: Effect of temperature and sediment type” corresponded by Prof. Dr. Aslı BAYSAL from Chemistry Department and founded by ITU was published in the “ENVIRONMENTAL RESEARCH” (Q1, IF: 8.88) aims to explore the differential effects of various microplastics and temperature on different sediments through the metabolic and oxidative responses of gram-negative P aeruginosa.

To access full article, https://www.sciencedirect.com/science/article/pii/S0013935124002536.

A book chapter named “Biofouling: Status and challenges in the marine environment” on “Nanotechnology to Monitor, Remedy, and Prevent Pollution” was published by Prof. Dr. Aslı BAYSAL

The chapter “Biofouling: Status and challenges in the marine environment” authored by Prof. Dr. Aslı BAYSAL from Chemistry Department was published in the “Nanotechnology to Monitor, Remedy, and Prevent Pollution” .In this chapter, they discussed biofouling dynamics in marine environment (e.g., distribution, diversity, substrate and organism interaction, relationship with substrate–organism interaction and marine geochemical–physical characteristics), yesterday’s today’s and tomorrow’s prevention and management strategies, and control of biofouling using new approaches (e.g., bioinspired, nano-based, or combined methods) and traditional chemical, biological, and physical methods. Moreover, this chapter aims to highlight known or potential hazards of biofouling control strategies on marine environment and human. In addition, the impact and management of biofouling in the marine environment is evaluated towards sustainability, such as economic, energy aspects, and highlight knowledge gaps, areas for future research, and potential impacts of marine biofouling.

A book chapter named “Micropollutants in water and their adverse effects on environment and human life” on “Nanotechnology to Monitor, Remedy, and Prevent Pollution” was published by Prof. Dr. Aslı BAYSAL

The chapter “Micropollutants in water and their adverse effects on environment and human life” authored by Prof. Dr. Aslı BAYSAL from Chemistry Department was published in the “Nanotechnology to Monitor, Remedy, and Prevent Pollution”. This chapter aims to classify the existing and emerging micropollutants by their occurrence and concentrations in various water systems such as drinking, groundwater, and surface water. Moreover, in order to rank the micropollutants in water systems, the hazard estimation of micropollutants is conducted using available environmental risk assessment approaches (e. g. contamination factor, risk quotient, human health hazard estimations). Furthermore, by this ranking of micropollutants, the biological impact of each micropollutants is assessed from higher to lower organisms (e. g. animals, human cells, invertebrates, microorganisms) to understand the adverse impact on the environment and human health using experimental studies like in vitro, in vivo studies etc. The chapter also highlight knowledge gaps and areas for future research of micropollutants on environmental and human health.

Prof. Dr.  Barış Kışkan has won The Lifetime Contribution Award for Polybenzoxazine Research, Chulalongkorn University, Bangkok, Thailand

In a distinguished ceremony held at Chulalongkorn University in Bangkok, Thailand, Prof. Dr. Barış Kışkan was honored with The Lifetime Contribution Award for his extensive and impactful research in Polybenzoxazine. This prestigious award recognizes Prof. Kışkan's significant contributions to the field, which have influenced both academic research and industrial applications globally. His pioneering work has not only advanced the understanding of polybenzoxazine chemistries but also paved the way for new innovations in high-performance materials.

Barış Kışkan is a Professor at Istanbul Technical University, Chemistry Department. He received his Ph.D. degree from the Chemistry Department of Istanbul Technical University under the supervision of Prof. Dr. Yusuf Yağcı. He studied in Max-Planck Institute of Colloids and Interfaces (Golm, Germany). His research mainly focuses on thermosetting polymers, Self-Healable Polymers, Sustainable Materials Photopolymerization, Polymer Recycling and Upcycling and polymer synthesis. He is the co-author of more than 100 research papers, and a co-inventor on several patents Accordingly, his articles have received 8860 citations (h-index=51, i-10 index=91) on Google Scholar. He is the recipient of several national science awards.

Prof. Dr. Turan Öztürk won the 2023 ITU Science Award.

 (Basic Sciences field)

Prof. Turan Öztürk received his PhD degree from the University of East Anglia, UK, and then moved to the University of Kent at Canterbury, UK, as a postdoctoral fellow, where he developed a new method for the synthesis of fused 1,4-dithiin and thiophene rings from 1,8-diketones using Lawesson's reagent and P4S10. He took up a position at TUBITAK MRC, Turkey, then Middle East Technical University, Turkey, and joined Istanbul Technical University (İTÜ) as a full professor. He has previously been British Council Research Fellow, NATO Research Fellow and Honorary Lecturer at the University of Kent at Canterbury, and Senior Research Fellow at University of Waterloo, Canada. His research interests concentrate on the development of new organic materials, particularly including thienothiophene and dithienothiophene, having electronic and optical properties.

The doctoral thesis titled "Synthesis of Organic Energy Materials; Investigation of Their Properties and Device Applications" by Dr. Recep İŞÇİ, completed under the supervision of Prof. Dr. Turan ÖZTÜRK, a faculty member of our Chemistry Department, has been awarded the 2023 Best Doctoral Thesis Award.

The doctoral thesis titled "Synthesis of Organic Energy Materials; Investigation of Their Properties and Device Applications" by Dr. Recep İŞÇİ, completed under the supervision of Prof. Dr. Turan ÖZTÜRK, a faculty member of our Chemistry Department, has been awarded the 2023 Best Doctoral Thesis Award. This prestigious recognition highlights the groundbreaking research conducted by Dr. İŞÇİ, focusing on the innovative synthesis of organic energy materials and their potential applications in advanced devices. The thesis stands out for its comprehensive exploration of material properties and practical applications, contributing significantly to the field of energy materials and positioning İTÜ at the forefront of cutting-edge research.

A book chapter named “Sample preparation and enrichment methods in capillary electrophoresis applications” on Elsevier Reference Collection in Chemistry, Molecular Sciences and Chemical Engineering was published by Assoc. Prof. Dr. Zeynep KALAYCIOĞLU and Prof. Dr. F. Bedia ERİM

Capillary electrophoresis (CE) provides fast separation with high resolution for complex samples and consumes only small sample volumes. This chapter introduces sample preparation and enrichment techniques in capillary electrophoresis analysis. The first part handles the theory of separation mechanism and instrumentation of capillary electrophoresis. The second part discusses various liquid-phase microextraction (LPME) and solid-phase microextraction (SPME) techniques in-line or at-line, and on-line coupled to commercial CE instruments. The third part covers on-line derivatization procedures to enhance detection sensitivity in CE when coupled with a laser-induced fluorescence detector. The fourth part discusses the on-line sample enrichment techniques specifically focusing on sample stacking methods. The final part covers the off-line LPME-CE techniques. Each part gives examples from the literature on biological, medical, clinical, and environmental analysis.