Cem Gök

The recovery of rare earth elements like neodymium (Nd(III)) has gained significant attention due to their critical industrial role and potential environmental impact when released into ecosystems. In this study, a novel biosorbent system combining poppy oil and alginate was developed as a bigel matrix for the efficient uptake of neodymium ions from aqueous solutions. The bigel was synthesized using a hydrogel (alginate) and an oleogel (poppy oil and beeswax) structure, combining the advantages of both materials for enhanced biosorption performance. The biosorption process was optimized by varying pH, temperature, and contact time. The maximum biosorption capacity was determined as 91.40 mg/g at pH 4.0, with an equilibrium time of 120 min and a temperature of 25°C, according to the linearized Dubinin–Radushkevich isotherm model. The biosorption yield increased from 64.45% to 81.23% with increasing temperature from 25 to 55°C. Thermodynamic analysis confirmed that the process is endothermic and spontaneous, with an enthalpy of 24.69 kJ/mol, an entropy of 139.7 J/mol · K, and a Gibbs free energy ranging from −16.95 to −21.14 kJ/mol. Linear and non‐linear isotherm models evaluated the system. The Freundlich model best described the biosorption, suggesting surface heterogeneity and multilayer adsorption. scanning electron microscopy (SEM), energy dispersive X‐ray spectroscopy (EDS), and Fourier transform infrared spectroscopy (FT‐IR) analyses confirmed the structural integrity of the bigel and the successful adsorption of Nd(III), with EDS revealing 21.65 wt.% Nd(III) on the biosorbent. These findings demonstrate that the poppy oil–alginate bigel is a promising and environmentally friendly biosorbent for neodymium recovery, with potential applications in sustainable resource recovery and waste management.

In this study, having focused on biosensor production, three different experimental sets were produced: a control group (substrates based on pure poly (3-hexylthiophene) and polylactic acid composite materials), samples exposed to pure water, and samples interacting with drug molecules. The electrical and optical behavior of these biosensors was then systematically investigated. P3HT/PLA blends were coated on glass substrates at ratios of 33-66% and 66-33%, respectively, to obtain sensing surfaces. Current-voltage (I-V) and UV-Vis spectroscopy measurements were conducted on the prepared samples at room temperature. Following the stabilization process following the addition of pure water and drug, repeated measurements revealed changes in the I-V characterization and UV-Vis measurements of the drug-treated samples. The change in the electrical and optical behavior of the P3HT/PLA-coated glass substrate resulting from the biochemical interaction with the drug is considered a promising development in biosensor technology.

Bioplastics are polymers that are biodegradable even under unsuitable post-use conditions and are mostly produced from renewable resources. The main aim of this research is to develop a valid and reliable scale to measure bioplastic awareness. A quantitative research approach was adopted and a survey model was utilized within this scope. Convenient sampling was preferred in determining the participants. Validity and reliability analyses of the scale were conducted on a sample (n=261) of university students studying at the 1st, 2nd, 3rd and 4th year levels. In the result of preparing open-ended questions and reviewing the relevant literature, a pool of 34 items was created. As a result of the content validity study conducted in line with the opinions of field experts, three items were removed and a draft scale of 31 items was obtained. In the results of exploratory factor analysis, four more items were eliminated and a two-factor structure was determined. The Bioplastic Awareness Scale (BIAAS) consists of a total of 27 items, 17 of which are in the first sub-dimension and 10 of which in the second sub-dimension. The first sub-dimension was named “environmental awareness,” and the second sub-dimension was named “reasons for using bioplastics.” The total variance explained by the two-factor structure was 42.768%, with which 23.591% were explained by the first factor and 19.177% by the second factor. The factor loadings of the items in the first sub-dimension ranged from 0.45 to 0.66, whereas the factor loadings of the items in the second sub-dimension ranged from 0.52 to 0.77. as a result of confirmatory factor analysis, RMSEA = 0.077 and SRMR = 0.066 values are gathered. The Cronbach's Alpha reliability coefficient for the overall scale was calculated as 0.92.

Autografts, allografts or xenografts can be applied for treating damaged skin tissue, but these methods have certain disadvantages such as additional damage to donor regions, increased infection risk, and risk of disease transmission. On the other hand, tissue engineered skin substitutes provide more advantageous properties including large sources and good bioactivity. Tissue engineering is an interdisciplinary field of science that aims to develop tissue-engineered substitutes or tissue scaffolds in order to replace, repair, maintain, and regenerate the tissue functions. For producing functional tissue scaffolds for use in tissue engineering, different fabrication methods have been used by scientists. One such technique is electrospinning, which has been recognized as a promising method for creating microstructures that closely resemble the extracellular matrix of skin tissue. In this review article, the aim was first to provide information about skin tissue-related problems, current treatment methods, electrospinning method and its working principle, and to review the recent literature on the applications of electrospinning for use in skin tissue engineering.

Bone is a tissue that can regenerate and repair itself when minor damage occurs; however, it is insufficient to repair large defects. Today, various treatments to repair bone defects are limited due to risks such as lack of donors, genetic differences, infection, and tissue rejection. Although traditional metals are used extensively in bone treatments, these materials have many disadvantages. In recent years, biodegradable biopolymers such as poly(lactic) acid (PLA), polyetheretherketone (PEEK), polycaprolactone (PCL), and poly (glycolic acid) PGA have attracted growing interest due to their properties such as lightweight, high mechanical strength, biocompatibility, and high processability. In recent years, these polymer materials have been extensively used in the medical field. PLA is known to be preferred in bone tissue engineering applications as it is a biomaterial that supports cell processes, including migration, proliferation, distribution, and differentiation. In recent years, alongside traditional methods for producing bone scaffolds, innovative technological approaches have emerged. Traditional manufacturing methods, however, often lack precise control over scaffold porosity, prompting a shift towards advanced designs and rapid prototyping techniques. In bone scaffolds produced with additive manufacturing, it is possible to create 3D porous bone scaffolds with internal connections. In addition, PLA-based composite scaffolds have been studied to improve the mechanical and biological properties of pure PLA bone scaffolds, such as osteogenicity, porosity, and mechanical strength. This study presents a review of the PLA-based composite bone scaffolds in bone tissue engineering applications.

Bacterial cellulose (BC) is a high-purity biopolymer with excellent physicochemical and mechanical properties, including high crystallinity, water absorption, biocompatibility, and structural tunability. However, its large-scale production is hindered by high substrate costs and limited sustainability. In this study, spent black tea waste was utilized as a low-cost and eco-friendly carbon source for BC synthesis by Komagataeibacter xylinus ATCC 53524 under varying initial pH conditions (4–9). Six different BC membranes were produced and systematically characterized in terms of mechanical strength, water absorption capacity, electrical conductivity, antimicrobial performance, and polyvinyl alcohol (PVA) attachment efficiency. Morphological and chemical analyses were conducted using SEM and FTIR techniques to investigate pH-induced structural variations. The results revealed that the BC6 sample (pH 6) exhibited the highest tensile strength (2.4 MPa), elongation (13%), PVA incorporation (12%), and electrical conductivity, confirming the positive impact of near-neutral conditions on nanofiber assembly and functional integration. In contrast, the BC4 sample (pH 4) demonstrated strong antimicrobial activity (log reduction = 3.5) against E. coli, suggesting that acidic pH conditions enhance bioactivity. SEM images confirmed the most cohesive and uniform fiber morphology at pH 6, while FTIR spectra indicated the preservation of characteristic cellulose functional groups across all samples. Overall, this study presents a sustainable and efficient strategy for BC production using food waste and demonstrates that synthesis pH is a key parameter in tuning its functional performance. The optimized BC membranes show potential for biomedical, flexible electronic, and antibacterial material applications, particularly in wearable electrode technologies.