Catalina Natalia Cheaburu-Yilmaz

Itaconic acid (IA) is an important bio-based platform chemical with applications in the production of polymers, coatings, resins, and other value-added materials. However, its conventional microbial production relies predominantly on microorganisms that present safety and process-related limitations. This study investigated Saccharomyces cerevisiae BY4742 as a potentially safer microbial platform for the production of bio-based IA under submerged fermentation conditions. IA production was optimized using response surface methodology with a Box–Behnken design, considering glucose concentration, initial pH, and CaCI₂ concentration as independent variables. The maximum IA concentration of 1133.50 ± 54.92 mg/L was obtained at 30 °C, pH 4.5, with 10% (w/v) glucose and without CaCI₂ supplementation after 216 h of fermentation. The fermentation-derived IA was subsequently recovered and characterized using high-performance liquid chromatography, Fourier-transform infrared spectroscopy, ¹H-nuclear magnetic resonance (¹H-NMR), and thermogravimetric analysis. The analytical results confirmed the molecular identity and high chromatographic purity of the recovered IA. Furthermore, the homopolymerization ability of the fermentation-derived IA was evaluated and compared with that of commercial IA under the same reaction conditions. The ¹H-NMR results demonstrated changes consistent with consumption of the IA C=C double bond following polymerization, indicating that the fermentation-derived IA retained its ability to undergo homopolymerization. Overall, these findings demonstrate the potential of S. cerevisiae for producing structurally confirmed bio-based IA and provide a proof of concept for its use as a renewable monomer for poly(itaconic acid) synthesis, supporting its further investigation for the development of bio-based polymeric materials.

The increasing presence of toxic pollutants in aquatic and terrestrial environments has motivated the need for advanced materials capable of both rapidly detecting and efficiently removing these contaminants. In this review, we summarize recent progress in nanocomposites designed for the simultaneous sensing and remediation of water and soil contaminants, with particular emphasis on heavy metals. We discuss material design strategies, functional components, detection mechanisms, and adsorption performance, highlighting key structure–property relationships. Despite significant advances in sensing and remediation technologies, most existing reviews focus on these functions independently, providing limited discussion of multifunctional materials capable of integrating both processes within a single platform. Our review addresses this gap by critically examining recent developments in advanced nanocomposites for simultaneous pollutant detection and removal, emphasizing material design strategies, structure–property relationships, adsorption and sensing mechanisms, physicochemical characteristics, practical challenges, and future perspectives toward sustainable environmental remediation technologies.

Hyaluronic acid (HA) hydrogels have attracted increasing interest for biomedical applications due to their tunable properties and biocompatibility. Methods: In this study, hyaluronic acid HA-based hydrogels were developed using two distinct crosslinking strategies: physical crosslinking through poly(vinyl alcohol) (PVA) incorporation and covalent crosslinking via DCC/NHS-mediated reactions. Piroxicam (Px) was included as a model drug to evaluate the drug delivery potential of the resulting systems. The hydrogels were characterized in terms of morphology, swelling behaviour, adhesion, enzymatic degradation, drug release, and in vitro cytocompatibility. Results: The results indicate that formulation parameters significantly influence the overall performance of the systems. PVA-containing hydrogels exhibited higher swelling capacity and improved adhesive properties, while covalently crosslinked networks showed reduced swelling and enhanced structural stability and resistance to enzymatic degradation. Drug release profiles were dependent on network structure, with more compact systems displaying slower release behaviour. In vitro assays suggested that the developed hydrogels are cytocompatible and that drug incorporation influences both release kinetics and cellular response. However, it should be noted that the biological evaluation was performed under simplified in vitro conditions, which primarily reflect specific aspects such as cell viability and migration. Conclusions: This study provides a comparative analysis of physical and covalent crosslinking strategies within a HA platform and highlights how formulation variables influence key physicochemical and biological properties. These findings contribute to the rational design of HA-based hydrogels, although further studies are required to establish their performance in more complex biological environments.

Marine algae are a sustainable and eco-friendly resource, growing rapidly without freshwater or arable land while aiding carbon sequestration. Their extract is rich in biodegradable polysaccharides like alginate, fucoidan, carrageenan, agar, and Ulvan which can be used further in wound healing thanks to their unique characteristics such as ensuring moisture balance and tissue regeneration by forming biocompatible hydrogels with antimicrobial, anti-inflammatory, and antioxidant properties, key requirements in wound healing. The present study explored the utilization of local grown marine algae (i.e., Aegean seashores from Türkiye) and transforming the waste into useful end-products for dermatocosmetics and healing systems. The extracted polyssacharide, e.g., Ulvan which was characterized by means of FT-IR spectroscopy, DSC, and antioxidant activity, was included inside a semi-solid formulation and combined with other polysaccharides from other natural sources such a chitosan, alginate, and hyaluronic acid to form bioactive hydrogels with wound closure activity. The formulated hydrogels exhibited significant swelling capacity, antioxidant activity, and the selected optimal formulation exhibited enhanced wound closure rates in vitro, demonstrating potential for wound-healing applications.

Phytic acid, as a natural originated compound with multi phosphate side groups, is known to increase the corrosion protection and thermal resistance of the coatings. In this study, two different acrylic emulsion polymers containing epoxy and silane reactive functional groups (glycidyl methacrylate (GMA) and vinyltriethoxysilane (VTES)) were synthesized via emulsion polymerization and mixed with phytic acid (PA) solution in different ratios (5, 10, 15 wt%) for use as binders in leather finishing applications. The colloidal stability, particle size distribution, and chemical structures of the synthesized polymers were characterized through comprehensive analyses. The resulting reactive copolymer dispersions were used as binders in finishing formulations and applied to crust shoe upper leathers The coating performance was evaluated in terms of rub fastness, flex resistance, water spotting, and thermal resistance, using the unmodified reactive acrylic binders (G0 and V0) as reference systems to assess the improvements achieved. Both phytic acid-modified binders exhibited strong film integrity and maintained high dry rub fastness up to 2000 cycles and wet rub fastness up to 250 cycles at phytic acid concentrations of 5–10 wt%. Increasing the phytic acid content beyond this range led to reduced dispersion stability and partial loss of coating performance. The results confirm that incorporating moderate levels of phytic acid into reactive acrylic emulsions enhances coating durability and thermal resistance without compromising film appearance, offering a safer and more sustainable alternative to conventional crosslinking systems for leather finishing applications.

When developing a topical formulation, it is essential to evaluate it from the perspective of its carrier capacity for the controlled release of the encapsulated drug. The drug should be simply quantified through an accurate and reproducible method. This paper presents a rapid, simple, sensitive, and reproducible high-performance liquid chromatography method with UV detection for evaluating the ability of chitosan-graft-β-cyclodextrin/PVA (CS-g-β-CD/PVA) hydrogels as carriers for the controlled release of vemurafenib (VEM). The chromatographic separation was achieved using a Waters CORTECS C18 column (100 × 2.1 mm ID, 2.7 µm). The mobile phase was a mixture of: A (water/formic acid - 99.9/0.1, v/v), B (acetonitrile), and C (methanol) in the ratio of 40:55:5 (v/v/v). The injection sample amount was 10 μL, and the run time was 9 minutes in isocratic mode at a flow rate of 1 mL/min. The analyte was detected using UV absorption at 252 nm. The standard calibration curve was linear over the concentration range of 0.78-100 mg/L. The values for LOD and LOQ were 0.5 mg/L and 0.75 mg/L, respectively. The intra- and inter-day precision of measurements were lower than the accepted criteria (RSD ≤ 2%). The high value of recoveries obtained for VEM indicates that the proposed method was found to be accurate. The stability of VEM solutions was assessed, indicating that the drug remained stable under all relevant conditions. Finally, the validated method was successfully applied to evaluate the ability of chitosan-graft-β-cyclodextrin/PVA hydrogels to load and sustain release of VEM. The drug entrapment efficiency (DEE%) was between 65±0.08% and 70±0.05%.

All acute and chronic wound management strategies have limitations. Therefore, there is an urgent need to develop new treatment options for wound healing. Hydrogels based on natural polymers offer advantages in wound management because they can reduce patients’ pain, fight infection, and carry targeted drugs to speed up the healing process. In this study, we aimed to develop and investigate an alginate-grafted N-vinylcaprolactam-based matrix for a modified release of dexketoprofen (DEX), which is potentially useful in wound healing. Free radical polymerization and grafted techniques were used to prepare thermo-responsive hydrogels. The obtained hydrogels, unloaded hydrogel (HY) and dexketoprofen-loaded hydrogel (DEXHY), were characterized and analyzed. The concentration of DEX encapsulated in the polymer matrix was 4 mg/mL. The IC50 values found for the samples tested by us were 607.4 µg/mL for HY, 950.4 µg/mL for DEXHY, and 2239 µg/mL for DEX. The average value of cell viability (%) after the exposure of cells to DEXHY hydrogel was 75.4%. DEXHY exhibited a very good in vitro wound closure rate, given its ability to modify DEX release kinetics. The hydrogel developed in this study has shown considerable potential to facilitate and even accelerate wound healing, including surgical wounds, by inhibiting the overexpressed inflammation process.

Nowadays, large amounts of wastewater arise from various industrial applications. The discharge of wastewater into the environment represents a threat to the aquatic ecosystem and human health. Thus, in the present study, innovative double-network (DN) hydrogels with pH-sensitive features and applicability as adsorbents in the treatment of leather dye wastewater were prepared. The polyelectrolyte, poly(N,N-dimethylaminoethyl methacrylate (PDMAEMA), was obtained via the radical polymerization process, while the supramolecular structure was co-assembled through physical interactions. As a novelty, the double network was obtained through the interpenetration of the supramolecular network in the cross-linked polymeric one. The new hydrogels were physico-chemically and morphologically characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and in terms of thermogravimetric analysis (TGA), swelling degree measurements, and dye adsorption studies. The DN hydrogels present interconnected macropores and high thermal stability. The swelling capacity of the dual network gels highlights a superadsorbent behavior at pH 3. Furthermore, the dye adsorption study highlights the effects of several variables (pH, concentration dose of adsorbent) on the ability of the gels to adsorb an anionic dye. The adsorption kinetics of the anionic dyes fitted the pseudo-first-order model (PFO). The estimated maximum adsorption capacities for the anionic dyes was 451 mg g⁻¹ for PDMAEMA and 545 mg g⁻¹ for DN gel.

This study investigates the synthesis and application of acrylic–urethane hybrid polymer dispersions as advanced binders for leather finishing. Two polymerization techniques—seeded emulsion and miniemulsion—were used to produce hybrid polymer dispersions by varying the ratios of polyurethane (PU) and acrylic (AC). The synthesized dispersions, i.e., the hybrid polyurethanes, showed stable, uniform particle sizes, inferring good compatibility and interaction between the PU and AC phases, as confirmed by particle sizes, FTIR, and DSC analyses. The performance of the coating on leather surfaces was assessed by using standard physical tests, including rubbing fastness, flexing endurance, water spot resistance, and grain strength. The results showed that the hybrid polymers outperformed their individual PU and AC counterparts, particularly in terms of abrasion resistance and mechanical integrity. Of the two polymerization techniques, the seeded emulsion hybrids exhibited superior coating properties, providing greater resistance to cracking and abrasion under stress, improved grain strength, and better color retention during rubbing tests. These findings highlight the potential of acrylic–urethane hybrids, particularly those prepared via seeded emulsion polymerization, to address the limitations of traditional binders in high-performance leather applications.

The topical therapy with rifampicin (RF)-based formulations is beneficial for treating postoperative wound infections and to accelerate healing. Despite recent research highlighting the antibiotic’s significant anti-inflammatory properties, limited topical wound healing products are currently available. The present study aimed to prove that the newly synthesized nanoparticles based on grafted alginate and poly(N-vinylcaprolactam) (pNVCL) and poly-lactic-co-glycolic acid (PLGA) contribute to the healing process of a wound. The methods used were at first the synthesis of the copolymer of alginate and pNVCL via grafting from technique and radical polymerization followed by water-in-oil-in water (W/O/W) emulsification; as oil phase PLGA dissolved in dichloromethane (DCM) was used. The formed nanoparticles were than characterized. The loaded RF was determined to be 160 µg/mL for a 20 mg formulation and within a four-hour time frame approximately 10% of the total loaded amount was released. The inhibitory concentrations (IC50) were 192.1 µg/mL for the nanoparticle, 208.8 µg/mL for pure rifampicin, and 718.1 µg/mL for the rifampicin-loaded nanoparticles. Considering the double role rifampicin was used for, the result was considered satisfactory in the way that these formulations could be used predominantly for postoperative wound irrigation in order to avoid infections and to improve healing.