Bahar Aslanbay Guler

Chemobrionics has garnered significant interest across various scientific disciplines, including chemistry, physics, material science, and regenerative medicine. To broaden their application field, hybrid materials can be developed by incorporating organic or biological components into their chemical composition. In the present study, it is aimed to synthesize a hybrid biochemobrionic material by incorporating Chlorella vulgaris microalgae into the calcium–magnesium silicate–phosphate chemobrionic structure. Two different techniques are compared for fabrication of biochemobrionic material. Additionally, antioxidant activity, degradation behavior, and cytotoxicity of the biochemobrionic are investigated. While the coating method is found to be more successful in enriching the material content with organic components, the direct incorporation method is deemed more suitable for biochemobrionic production due to the homogeneous distribution of microalgae, as well as the stability and mechanical strength of the material. According to the results, integrating C. vulgaris biomass not only enhances the antioxidant capability of the biochemobrionic material but also accelerates its degradation rate. Furthermore, in vitro cytotoxicity assessment reveals no notable adverse effects for both chemobrionic and biochemobrionic specimens, though surface modifications can potentially boost cell viability. In conclusion, the direct incorporation method emerges as a promising approach for integrating a wide variety of components into chemobrionic structures.

Microalgae are considered a promising source for obtaining natural compounds with strong antioxidant activity. Despite the great progress made in this field, there is still need for further studies applying simple and cost-effective modifications to reveal their full potential and enhance antioxidant properties. Arthrospira platensis and Chlorella vulgaris are some of the most common cells studied for this purpose. In this study, it was aimed to develop a bioprocess for the enhancement of antioxidant properties of these two microalgae by evaluating the effect of different culture conditions. With this aim, the impacts of light intensity/reactive oxygen species and nitrogen sources/reactive oxygen species were evaluated for the A. platensis and C. vulgaris cells, respectively. Results showed that the antioxidant potential of A. platensis was found to be correlated with the phycocyanin and total phenolic content of cells, and 80 µmol photons m⁻² s⁻¹ light intensity induced antioxidant activity in a two-step cultivation mode. For C. vulgaris cells, maximum antioxidant activities of 68.10 ± 1.51% and 75.68 ± 0.66% were obtained in cultures with NH₄Cl (0.016% (w/v)) for DPPH and ABTS assays, respectively. The applied oxidative stress factors exhibited different effects on the antioxidant activities of the cells because of their cellular morphologies and changing mechanisms of reactive oxygen species. These outcomes show the potential of applied modifications on cells and suggest a promising route to enhance antioxidant activities of microalgae for further research.

Chemical gardens are an exciting area of self-organized precipitation structures that form nano- and micro-sized structures in different shapes. This field has attracted great interest from researchers due to the specific characteristics and potential applications of these structures. Today, research on chemical gardens has provided deeper information regarding the formation mechanisms of these structures, and several techniques have been developed for chemical garden growth. However, they all show different growth patterns and lead to the formation of structures with a variety of morphological, chemical, or physical properties. This study aimed to evaluate the effects of different production techniques on chemical garden growth, taking into consideration the growth patterns, morphology, microstructure, and chemical composition. The chemical garden structures obtained in seed and injection experiments, two common methods, showed highly similar surface structures, void formation, and chemical composition. The membrane growth method has a small number of applications; thus, it was comprehensively evaluated to add new insights to the existing limited data. It produced the most stable and standard structures in a flat sheet-like shape and showed different morphologies than those observed in other two methods. Overall, this study presented significant results about the effect of growth techniques on chemical garden structures and similar systems.

3D cell culture approaches are cell culture methods that provide good visualization of interactions between cells while preserving the natural growth pattern. In recent years, several studies have managed to implement magnetic levitation technology on 3D cell culture applications by either combining cells with magnetic nanoparticles (positive magnetophoresis) or applying a magnetic field directly to the cells in a high-intensity medium (negative magnetophoresis). The positive magnetophoresis technique consists of integrating magnetic nanoparticles into the cells, while the negative magnetophoresis technique consists of levitating the cells without labelling them with magnetic nanoparticles. Magnetic levitation methods can be used to manipulate 3D culture, provide more complex habitats and custom control, or display density data as a sensor.The present review aims to show the advantages, limitations, and promises of magnetic 3D cell culture, along with its application methods, tools, and capabilities as a density sensor. In this context, the promising magnetic levitation technique on 3D cell cultures could be fully utilized in further studies with precise control.

Astaxanthin is one of the most attractive carotenoid in the cosmetic, food, pharmaceutical, and aquaculture industries due to its strong bioactive properties. Among the various sources, several algae species are considered as rich sources of astaxanthin. Downstream processing of algae involves the majority of the total processing costs. Thus, elimination of high energy involved steps is imperative to achieve cost-effective scale in industry. This study aimed to determine operation conditions for astaxanthin extraction from wet Haematococcus pluvialis using microwave-assisted extraction. The isolated astaxanthin extract was evaluated for cytotoxicity on human lung cancer cells. The microwave-assisted extraction process at 75 °C under the power of 700 Watt for 7 min gave the highest astaxanthin yield (12.24 ± 0.54 mg astaxanthin/g wet cell weight). Based on MTT cell viability and Hoechst 33342 nuclear staining assays on A549 lung cancer cells, astaxanthin inhibited cell growth in dose- and time-dependent manners, where IC₅₀ value was determined as 111.8 ± 14.8 µg/mL and apoptotic bodies were observed along with positive control group at 72 hr. These results showed that the treatment with astaxanthin extracted from wet H. pluvialis by microwave-assisted extraction exhibited anti-cancer activity on lung cancer cells indicating a newly potential to be utilized in industry.

Tek hücreli, basit organizmalar olan mikroalgler, sahip oldukları karakteristik özellikleri sayesinde gıda, çevre teknolojileri, enerji, kozmetik, ilaç, akuakültür gibi çeşitli endüstrilerde yaygın olarak kullanılmaktadır. Mikroalglere ve uygulama alanlarına olan ilgi her geçen gün artış gösterse de endüstriyel çaptaki üretimlerde çeşitli sorunlarla karşı karşıya kalınabilmektedir. Organizmaların büyüme kinetiği ve hedef ürün eldesi proseslerdeki temel aşamalardan olup, bu aşamalarda meydana gelebilecek herhangi bir problem, sistemin tamamını olumsuz etkilemektedir. Bu problemleri önlemek için izlenebilecek yollardan biri, hücrelerin büyümesini ve ürün miktarını etkileyen parametrelerin kullanımıyla kinetik modeller geliştirilmesidir. Matematiksel modeller ile üretim sırasında elde edilen sonuçların sayısal olarak ifadesi sağlanmakta ve böylece ölçek büyütmede ve benzer proseslerde kullanılabilecek güvenilir veriler elde edilmektedir. Bu makalede, mikroalg hücrelerinin büyümesi ve ürün üretimine dair geliştirilen kinetik modeller substrat, ışık ve sıcaklık parametreleri açısından değerlendirilerek literatürde kullanılan modeller özetlenmiştir.

Fucoxanthin is a xanthophyll pigment which occurs in marine brown seaweeds (macroalgae), diatoms and several microalgae species. It forms with chlorophyll a-c and several proteins, a major fucoxanthin-chlorophyll a/c complex, which transfers light energy to the photosynthesis center and plays a major role in light harvesting. Recent studies have reported that fucoxanthin has many physiological functions and biological effects, such as anti-obesity, antidiabetic, anti-inflammatory, anticancer and cardiovascular system protection. Therefore, this pigment is highly preferred for the prevention and treatment of various chronic diseases. In addition, potential applications of high value fucoxanthin can be found in cosmetic, food and feed industries. In this review paper, the historical development, characteristic properties and possible sources of fucoxanthin are extensively described. The potential biological activities of fucoxanthin are also discussed. Finally, brief overview of common applications and market analysis of commercial fucoxanthin are also reported.