Biological Applications Research Articles

Anabaena sp. A-1 mediated molybdenum oxide nanoparticles: A novel frontier in green synthesis, characterization and pharmaceutical properties.

Green-synthesized metal oxide nanoparticles have garnered considerable attention due to their simple, sustainable, and eco-friendly attributes, coupled with their diverse applications in biomedicine and environmental context. The current study shows a sustainable approach for synthesizing molybdenum oxide nanoparticles (MoONPs) utilizing an extract from Anabaena sp. A-1. This novel approach marks a significant milestone as various spectral approaches were employed for characterization of the green-synthesized MoONPs. Ultraviolet-visible (UV-Vis) spectroscopic analysis revealed a surface plasmon resonance (SPR) peak of MoONPs at 538 nm. Fourier transform infrared (FTIR) spectral analysis facilitated the identification of functional groups responsible for both the stability and production of MoONPs. Scanning electron microscopy (SEM) was utilized revealing a rod shape morphology of the MoONPs. X-ray diffraction (XRD) analysis yielded a calculated crystal size of 31 nm, indicating the crystalline nature of MoONPs. Subsequently, biological assays were employed to ascertain the potential of the bioengineered MoONPs. The 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay was used to quantify free radical scavenging activity, revealing an antioxidant capacity of 68.1% at 200 μg/mL. To evaluate antibacterial and antifungal efficacy, the disc diffusion method was employed across varying concentrations of MoONPs (6.25, 12.5, 25, 50, 100, 150, 200 μg/mL). Quantification of cytotoxicity was performed via a brine shrimp assay, yielding an IC50 value of 552.3 μg/mL, a metric of moderate cytotoxicity. To assess the biocompatibility of MoONPs, an antihemolytic assay was conducted, confirming their safety profile. Additionally, MoONPs exhibited non-toxic attributes in an insecticidal assay. Notably, in anti-inflammatory assay MoONPs showed an inactive nature towards the reactive oxygen species. In conclusion, these findings highlight the potential versatility of MoONPs in various biological applications, extending beyond their recognized anti-inflammatory and insecticidal properties. RESEARCH HIGHLIGHTS: This study marks an advancement in nanotechnology, exploring ways for MoONPs fabrication, representing a unique and unexplored research domain. Green-synthesized MoONPs using Anabaena sp. A-1 extract offers a sustainable and eco-friendly approach. Characterized by UV-Vis, FTIR, SEM, and XRD, MoONPs demonstrate rod-shaped morphology and crystalline nature. Bioengineered MoONPs exhibit versatility in biological applications, demonstrating notable antioxidant, antibacterial and antifungal efficacy, moderate cytotoxicity, biocompatibility, and insecticidal properties, emphasizing their multifaceted utility. The research findings highlight the potential utilization of MoONPs across a spectrum of biological applications, thereby suggesting their promising role in the realm of biomedicine and environmental context.

Combination of Efficient Red Fluorescence and High Photothermal Conversion in the Second Near‐Infrared Window from Carbon Dots through Photoinduced Sodium‐Doping Approach

AbstractCarbon dots (CDs) are highly desired in biological applications. However, achieving a balance between photoluminescence (PL) efficiency and photothermal conversion efficiency (PTCE) is challenging. In this study, an unprecedent combination of efficient red fluorescence and high PTCE in the second near‐infrared (NIR‐II) window in a sodium‐doped CDs system is reported. Upon 808 nm laser irradiation, photo‐induced oxidation–reduction reactions happened on the surface of sodium cation‐functionalized CDs (Na‐CDs), leading to the partial reduction of surface‐functionalized sodium (Na) ions. The photo‐reduced Na atoms coordinated with sp2 C domains in the core, resulting in Na‐doped CDs (ir‐Na‐CDs) with an enhanced absorption band in the NIR‐II window and a high PTCE of 43% under 1064 nm laser irradiation (1 W cm−2). Composing the ir‐Na‐CDs with bovine serum albumin (BSA) enhanced the PLQY of the red emission to 31% in water without diminishing the PTCE in the NIR‐II region. Transient absorption spectra revealed that no energy transfer occurred between the red emission center and the NIR‐II absorption band, revealing a novel CDs system with independent Janus photophysical processes. Moreover, ir‐Na‐CDs@BSA exhibited negligible to low cytotoxicity and demonstrated tumor accumulation capacity after intravenous injection, enabling effective tumor photothermal therapy in the NIR‐II region.

Vacancy Engineering in 2D Transition Metal Chalcogenide Photocatalyst: Structure Modulation, Function and Synergy Application.

Transition metal chalcogenides (TMCs) are widely used in photocatalytic fields such as hydrogen evolution, nitrogen fixation, and pollutant degradation due to their suitable bandgaps, tunable electronic and optical properties, and strong reducing ability. The unique 2D malleability structure provides a pre-designed platform for customizable structures. The introduction of vacancy engineering makes up for the shortcomings of photocorrosion and limited light response and provides the greatest support for TMCs in terms of kinetics and thermodynamics in photocatalysis. This work reviews the effect of vacancy engineering on photocatalytic performance based on 2D semiconductor TMCs. The characteristics of vacancy introduction strategies are summarized, and the development of photocatalysis of vacancy engineering TMCs materials in energy conversion, degradation, and biological applications is reviewed. The contribution of vacancies in the optical range and charge transfer kinetics is also discussed from the perspective of structure manipulation. Vacancy engineering not only controls and optimizes the structure of the TMCs, but also improves the optical properties, charge transfer, and surface properties. The synergies between TMCs vacancy engineering and atomic doping, other vacancies, and heterojunction composite techniques are discussed in detail, followed by a summary of current trends and potential for expansion.

Breaking Barriers in Eco-Friendly Synthesis of Plant-Mediated Metal/Metal Oxide/Bimetallic Nanoparticles: Antibacterial, Anticancer, Mechanism Elucidation, and Versatile Utilizations

Nanotechnology has emerged as a promising field in pharmaceutical research, involving producing unique nanoscale materials with sizes up to 100 nm via physiochemical and biological approaches. Nowadays more emphasis has been given to eco-friendly techniques for developing nanomaterials to enhance their biological applications and minimize health and environmental risks. With the help of green nanotechnology, a wide range of green metal, metal oxide, and bimetallic nanoparticles with distinct chemical compositions, sizes, and morphologies have been manufactured which are safe, economical, and environment friendly. Due to their biocompatibility and vast potential in biomedical (antibacterial, anticancer, antiviral, analgesic, anticoagulant, biofilm inhibitory activity) and in other fields such as (nanofertilizers, fermentative, food, and bioethanol production, construction field), green metal nanoparticles have garnered significant interest worldwide. The metal precursors combined with natural extracts such as plants, algae, fungi, and bacteria to get potent novel metal, metal oxide, and bimetallic nanoparticles such as Ag, Au, Co, Cu, Fe, Zr, Zn, Ni, Pt, Mg, Ti, Pd, Cd, Bi2O3, CeO2, Co3O4, CoFe2O4, CuO, Fe2O3, MgO, NiO, TiO2, ZnO, ZrO2, Ag-Au, Ag-Cr, Ag-Cu, Ag-Zn, Ag-CeO2, Ag-CuO, Ag-SeO2, Ag-TiO2, Ag-ZnO, Cu-Ag, Cu-Mg, Cu-Ni, Pd-Pt, Pt-Ag, ZnO-CuO, ZnO-SeO, ZnO-Se, Se-Zr, and Co-Bi2O3. These plant-mediated green nanoparticles possess excellent antibacterial and anticancer activity when tested against several microorganisms and cancer cell lines. Plants contain essential phytoconstituents (polyphenols, flavonoids, terpenoids, glycosides, alkaloids, etc.) compared to other natural sources (bacteria, fungi, and algae) in higher concentration that play a vital role in the development of green metal, metal oxide, and bimetallic nanoparticles because these plant-phytoconstituents act as a reducing, stabilizing, and capping agent and helps in the development of green nanoparticles. After concluding all these findings, this review has been designed for the first time in such a way that it imparts satisfactory knowledge about the antibacterial and anticancer activity of plant-mediated green metal, metal oxide, and bimetallic nanoparticles together, along with antibacterial and anticancer mechanisms. Additionally, it provides information about characterization techniques (UV–vis, FT-IR, DLS, XRD, SEM, TEM, BET, AFM) employed for plant-mediated nanoparticles, biomedical applications, and their role in other industries. Hence, this review provides information about the antibacterial and anticancer activity of various types of plant-mediated green metal, metal oxide, and bimetallic nanoparticles and their versatile application in diverse fields which is not covered in other pieces of literature.

Hybrid upconverting/paramagnetic Fe3O4/Gd2O3:Er3+, Yb3+, Mg2+, Nd3+ nanoparticles – synthesis, characterisation and biological applications

The goals of this work are to design and develop a technology for fabrication and study of multifunctional properties of core/shell nanoparticles (NPs) as magnetic/luminescent markers. The new hybrid core/shell Fe3O4/Gd2O3:1% Er3+, 18% Yb3+, 2.5% Mg2+, x% Nd3+ NPs doped with different concentrations of neodymium ions, where x = 0%, 0.5%, 0.75%, 1%, 2%, 4%, were synthesized by the co-precipitation method. The NPs were characterised using XRD, TEM, SEM, EDX, confocal microscopy and photoluminescence. Fe3O4 (core) consists of several 13 nm NPs. The core/shell NPs have sizes from 220 nm to 641 nm. In this latter case, the shell thicknesses were 72, 80, and 121 nm. The upconversion efficiency properties and magnetic properties of the hybrid NPs were investigated. In the core/shell NPs, the addition of Nd3+ quenches the luminescence. The magnetic response of core/shell samples is rather paramagnetic and does not differ significantly from that registered for the shell material alone. For Gd2O3:1% Er3+, 18% Yb3+ and Fe3O4/Gd2O3:1% Er3+, 18% Yb3+, 2.5% Mg2+, 0.5% Nd3+, at 300 K, the values of the magnetization registered at ~ 40 kOe are similar and equal to ~ 5.3 emu·g−1. The survivability of the HeLa tumor cells with the presence of the core/shell NPs was investigated for 24 h. The NPs are non-toxic up to a concentration of 1000 µg·ml−1 and penetrate cells in the process of endocytosis which has been confirmed by confocal microscope studies.

Trends, progress and future directions of nanomaterial based sensors: a bibliometric overview

Purpose Nanosensors have a wide range of applications because of their high sensitivity, selectivity and specificity. In the past decade, extensive and pervasive research related to nanosensors has led to significant progress in diverse fields, such as biomedicine, environmental monitoring and industrial process control. This led to better and more efficient detection and monitoring of physical and chemical properties at better resolution, opening new horizons in the development of novel technologies and applications for improved human health, environment protection, enhanced industrial processes, etc. Design/methodology/approach In this paper, the authors discuss the application of citation network analysis in the field of nanosensor research and development. Cluster analysis was carried out using papers published in the field of nanomaterial-based sensor research, and an in-depth analysis was carried out to identify significant clusters. The purpose of this study is to provide researchers to identify a pathway to the emerging areas in the field of nanosensor research. The authors have illustrated the knowledge base, knowledge domain and knowledge progression of nanosensor research using the citation analysis based on 3,636 Science Citation Index papers published during the period 2011 to 2021. Findings Among these papers, the bibliographic study identified 809 significant research publications, 11 clusters, 556 research sector keywords, 1,296 main authors, 139 referenced authors, 63 nations, 206 organizations and 42 journals. The authors have identified single quantum dot (QD)-based nanosensor for biological applications, carbon dot-based nanosensors, self-powered triboelectric nanogenerator-based nanosensor and genetically encoded nanosensor as the significant research hotspots that came to the fore in recent years. The future trend in nanosensor research might focus on the development of efficient and cost-effective designs for the detection of numerous environmental pollutants and biological molecules using mesostructured materials and QDs. It is also possible to optimize the detection methods using theoretical models, and generalized gradient approximation has great scope in sensor development. Research limitations/implications The future trend in nanosensor research might focus on the development of efficient and cost-effective designs for the detection of numerous environmental pollutants and biological molecules using mesostructured materials and QDs. It is also possible to optimize the detection methods using theoretical models, and generalized gradient approximation has great scope in sensor development. Originality/value This is a novel bibliometric analysis in the area of “nanomaterial based sensor,” which is carried out in CiteSpace software.

Tracking the effects of PLGA-based nanoparticles on protein expression in living cells through quantitative proteomics.

Mass spectrometry (MS)-based proteomics can identify and quantify the differential abundance of expressed proteins in parallel, and bottom-up proteomic approaches are even approaching comprehensive coverage of the complex eukaryotic proteome. Protein-nanoparticle (NP) interactions have been extensively studied owing to their importance in biological applications and nanotoxicology. However, the proteome-level effects of NPs on cells have received little attention, although changes in protein abundance can reflect the direct effects of nanocarriers on protein expression. Herein, we investigated the effect of PLGA-based NPs on protein expression in HepG2 cells using a label-free quantitative proteomics approach with data independent acquisition (DIA). The percentage of two-fold change in the protein expression of cells treated with PLGA-based NPs was less than 10.15% during a 6 hour observation period. Among the changed proteins, we found that dynamic proteins involved in cell division, localization, and transport are more likely to be more susceptible to PLGA-based NPs.

Enhanced Hydrogen Bonding by Urea Functionalization Tunes the Stability and Biological Properties of Peptide Amphiphiles.

Self-assembled nanostructures such as those formed by peptide amphiphiles (PAs) are of great interest in biological and pharmacological applications. Herein, a simple and widely applicable chemical modification, a urea motif, was included in the PA's molecular structure to stabilize the nanostructures by virtue of intermolecular hydrogen bonds. Since the amino acid residue nearest to the lipid tail is the most relevant for stability, we decided to include the urea modification at that position. We prepared four groups of molecules (13 PAs in all), with varying levels of intermolecular cohesion, using amino acids with distinct β-sheet promoting potential and/or containing hydrophobic tails of distinct lengths. Each subset contained one urea-modified PA and nonmodified PAs, all with the same peptide sequence. The varied responses of these PAs to variations in pH, temperature, counterions, and biologically related proteins were examined using microscopic, X-ray, spectrometric techniques, and molecular simulations. We found that the urea group contributes to the stabilization of the morphology and internal arrangement of the assemblies against environmental stimuli for all peptide sequences. In addition, microbiological and biological studies were performed with the cationic PAs. These assays reveal that the addition of urea linkages affects the PA-cell membrane interaction, showing the potential to increase the selectivity toward bacteria. Our data indicate that the urea motif can be used to tune the stability of a wide range of PA nanostructures, allowing flexibility on the biomaterial's design and opening a myriad of options for clinical therapies.

Comment on Altaf et al. Non-Thermal Plasma Reduction of Ag+ Ions into Silver Nanoparticles in Open Atmosphere under Statistically Optimized Conditions for Biological and Photocatalytic Applications. Materials 2022, 15, 3826

Altaf et al. recently published in Materials, 2022; 15(11), 3826, about the synthesis of silver nanoparticles (AgNPs) using the non-thermal plasma reduction of AgNO3 salt and performed statistical optimization for the reaction conditions, i.e., (A) the concentration of a stabilizing agent, mM (B) concentration of AgNO3 salt, mM and (C) the reaction time, mins. We would like to point out that their writing on the statistical analysis (Box–Behnken response surface methodology for predicting the size of the nanoparticles) is not complete and, therefore, cannot be independently checked by the readers. The problems found in their report are as follows: the hard-to-find actual value of the uncoded units; a dubious claim about the middle levels of variable B (salt concentration); inconsistency in using coded vs. uncoded units in the table vs. the regression equation; and three center points with identical conditions give a dissimilar prediction of results. These serious issues need to be clarified and revised, as well as several writing errors, in order to uphold the standard of scientific publications.

Reply to Mangindaan, D. Comment on “Altaf et al. Non-Thermal Plasma Reduction of Ag+ Ions into Silver Nanoparticles in Open Atmosphere under Statistically Optimized Conditions for Biological and Photocatalytic Applications. Materials 2022, 15, 3826”

The authors of the mentioned paper are highly thankful to Dr [...]

Heat Shock Response and Heat Shock Proteins: Current Understanding and Future Opportunities in Human Diseases

The heat shock response is an evolutionarily conserved mechanism that protects cells or organisms from the harmful effects of various stressors such as heat, chemicals toxins, UV radiation, and oxidizing agents. The heat shock response triggers the expression of a specific set of genes and proteins known as heat shock genes/proteins or molecular chaperones, including HSP100, HSP90, HSP70, HSP60, and small HSPs. Heat shock proteins (HSPs) play a crucial role in thermotolerance and aiding in protecting cells from harmful insults of stressors. HSPs are involved in essential cellular functions such as protein folding, eliminating misfolded proteins, apoptosis, and modulating cell signaling. The stress response to various environmental insults has been extensively studied in organisms from prokaryotes to higher organisms. The responses of organisms to various environmental stressors rely on the intensity and threshold of the stress stimuli, which vary among organisms and cellular contexts. Studies on heat shock proteins have primarily focused on HSP70, HSP90, HSP60, small HSPs, and ubiquitin, along with their applications in human biology. The current review highlighted a comprehensive mechanism of heat shock response and explores the function of heat shock proteins in stress management, as well as their potential as therapeutic agents and diagnostic markers for various diseases.

Bridging systems biology and tissue engineering: Unleashing the full potential of complex 3D in vitro tissue models of disease.

Rapid advances in tissue engineering have resulted in more complex and physiologically relevant 3D in vitro tissue models with applications in fundamental biology and therapeutic development. However, the complexity provided by these models is often not leveraged fully due to the reductionist methods used to analyze them. Computational and mathematical models developed in the field of systems biology can address this issue. Yet, traditional systems biology has been mostly applied to simpler in vitro models with little physiological relevance and limited cellular complexity. Therefore, integrating these two inherently interdisciplinary fields can result in new insights and move both disciplines forward. In this review, we provide a systematic overview of how systems biology has been integrated with 3D in vitro tissue models and discuss key application areas where the synergies between both fields have led to important advances with potential translational impact. We then outline key directions for future research and discuss a framework for further integration between fields.

In Situ Synthesis and Self-Assembly of Peptide-PEG Conjugates: A Facile Method for the Construction of Fibrous Hydrogels.

Peptide-based hydrogels have gained considerable attention as a compelling platform for various biomedical applications in recent years. Their attractiveness stems from their ability to seamlessly integrate diverse properties, such as biocompatibility, biodegradability, easily adjustable hydrophilicity/hydrophobicity, and other functionalities. However, a significant drawback is that most of the functional self-assembling peptides cannot form robust hydrogels suitable for biological applications. In this study, we present the synthesis of novel peptide-PEG conjugates and explore their comprehensive hydrogel properties. The hydrogel comprises double networks, with the first network formed through the self-assembly of peptides to create a β-sheet secondary structure. The second network is established through covalent bond formation via N-hydroxysuccinimide chemistry between peptides and a 4-arm PEG to form a covalently linked network. Importantly, our findings reveal that this hydrogel formation method can be applied to other peptides containing lysine-rich sequences. Upon encapsulation of the hydrogel with antimicrobial peptides, the hydrogel retained high bacterial killing efficiency while showing minimum cytotoxicity toward mammalian cells. We hope that this method opens new avenues for the development of a novel class of peptide-polymer hydrogel materials with enhanced performance in biomedical contexts, particularly in reducing the potential for infection in applications of tissue regeneration and drug delivery.

Plasmonic-Driven Regulation of Biomolecular Activity In Situ.

Selective and remote manipulation of activity for biomolecules, including protein, DNA, and lipids, is crucial to elucidate the molecular function and to develop biomedical applications. While advances in tool development, such as optogenetics, have significantly impacted these directions, the requirement for genetic modification significantly limits their therapeutic applications. Plasmonic nanoparticle heating has brought new opportunities to the field, as hot nanoparticles are unique point heat sources at the nanoscale. In this review, we summarize fundamental engineering problems such as plasmonic heating and the resulting biomolecular responses. We highlight the biological responses and applications of manipulating biomolecules and provide perspectives for future directions in the field.

Unraveling metachronal wave effects on heat and mass transfer in Non-Newtonian fluid

Non-Newtonian fluids flow generated by “cilia” are critical in medicine and bio-medical engineering. Such investigations are created by the back-and-forth movement of a microscopic hair-like structure connected to the walls, which causes a metachronal wave to form and drive biological fluids. Motivated by a wide range of biological applications, this study aims to explain the incompressible flow of Ellis fluid caused by the propagation of an infinite metachronal wave train traveling along channel walls owing to constantly beating cilia. The problem is simplified by low Reynolds number and long wavelength assumption. The mathematical model is solved with the aid of symbolic computational software Mathematica 13 version. The consequences of emerging parameters are then shown in graphical form and discussed comprehensively. From the study, it is worth mentioning that velocity declines with increasing material constants. Temperature distribution is also improved in the core sector of the channel and reduced at the walls. It is predicted that this approach will make an essential contribution to the progress and enhancement of various types of drug delivery systems in the biomedical industry and biomechanics.

Therapeutic Potential, Pharmacological Activities and Analytical Aspects of Liriodendrin in Medicine: Novel and Potential Therapy Options for the Treatment of Human Disorders and Associated Complications

Abstract:: Natural products and their derived secondary metabolites play an important role in medicine and other allied health sectors. Liriodendrin is one of the main lignans of Boerhaavia diffusa roots. Liriodendrin is a lignin class phytochemical having numerous health beneficial properties in medicine, including anti-myocardial ischemia, anti-arrhythmic, anti-oxidant and anti- inflammatory potential. This present review aims to analyze the reported ethnomedicinal properties, pharmacological activities and analytical aspects of liriodendrin and identify the remaining gaps in medicinal fields for their future investigations. The pharmacological properties of liriodendrin have been described in the present paper in order to describe its better utilization in natural medicine in the future. Biological poptential and pharmacological activities of liriodendrin have been described in the present work with their analytical development in the scientific fields. In the present work, scientific data on liriodendrin were collected from different scientific databases such as PubMed, Springer, Google, Science Direct, and Google Scholar. They described their biological potential on the basis of the available scientific literature. Further, research and review articles from peer-reviewed journals were also searched during data collection. The present paper's scientific data signified the biological importance of liriodendrin in medicine, which has been isolated from Boerhaavia diffusa and other medicinal plants. Liriodendrin has biological potential against myocardial infarction, arrhythmias, lung injury, hepatic injury, antiinflammatory, ulcerative colitis, gastric injury, SARS-CoV-2 protease and intestinal inflammation. Further, its effectiveness in medicine was also due to its anti-convulsant activity, nitric oxide inhibitory potential, cytotoxicity, cytoprotective nature, anti-oxidant, and anti-microbial potential. The present paper's scientific data also described the metabolism and analytical development for their isolation, separation and identification in different samples. Detailed pharmacological activities of liriodendrin have been described here in the present work and highlighted its important pharmacological properties and analytical aspects. Liriodendrin is a valuable phytochemical of Boerhaavia diffusa, which has numerous biological applications in medicine. Further, this study can also validate the traditional and ethnobotanical use of the Boerhaavia diffusa and other plant material, which contain a significant amount of liriodendrin as an active phytochemical. Liriodendrin have huge biological potential far beyond its traditional uses in human complications.

Translational activation by a synthetic PPR protein elucidates control of psbA translation in Arabidopsis chloroplasts.

Translation initiation on chloroplast psbA mRNA in plants scales with light intensity, providing its gene product, D1, as needed to replace photodamaged D1 in Photosystem II. The psbA translational activator HIGH CHLOROPHYLL FLUORESCENCE 173 (HCF173) has been hypothesized to mediate this regulation. HCF173 belongs to the short-chain dehydrogenase/reductase superfamily, associates with the psbA 5'-untranslated region (5'-UTR), and has been hypothesized to enhance translation by binding an RNA segment that would otherwise pair with and mask the ribosome binding region. To test these hypotheses, we examined whether a synthetic pentatricopeptide repeat (sPPR) protein can substitute for HCF173 when bound to the HCF173 binding site. We show that an sPPR designed to bind HCF173's footprint in the psbA 5'-UTR bound the intended site in vivo and partially substituted for HCF173 to activate psbA translation. However, sPPR-activated translation did not respond to light. These results imply that HCF173 activates translation, at least in part, by sequestering the RNA it binds to maintain an accessible ribosome binding region, and that HCF173 is also required to regulate psbA translation in response to light. Translational activation can be added to the functions that can be programmed with sPPR proteins for synthetic biology applications in chloroplasts.

A novel ternary magnetic nanobiocomposite based on tragacanth-silk fibroin hydrogel for hyperthermia and biological properties.

This study involves the development of a new nanocomposite material for use in biological applications. The nanocomposite was based on tragacanth hydrogel (TG), which was formed through cross-linking of Ca2+ ions with TG polymer chains. The utilization of TG hydrogel and silk fibroin as natural compounds has enhanced the biocompatibility, biodegradability, adhesion, and cell growth properties of the nanobiocomposite. This advancement makes the nanobiocomposite suitable for various biological applications, including drug delivery, wound healing, and tissue engineering. Additionally, Fe3O4 magnetic nanoparticles were synthesized in situ within the nanocomposite to enhance its hyperthermia efficiency. The presence of hydrophilic groups in all components of the nanobiocomposite allowed for good dispersion in water, which is an important factor in increasing the effectiveness of hyperthermia cancer therapy. Hemolysis and 3-(4,5 dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide assays were conducted to evaluate the safety and efficacy of the nanobiocomposite for in-vivo applications. Results showed that even at high concentrations, the nanobiocomposite had minimal hemolytic effects. Finally, the hyperthermia application of the hybrid scaffold was evaluated, with a maximum SAR value of 41.2W/g measured in the first interval.

Production of 14α-Hydroxy Progesterone Using a Steroidal Hydroxylase from Cochliobolus lunatus Expressed in Escherichia coli

Steroids with hydroxylation at C14 are drawing increased attention because of their diverse biological activities and applications. P-450lun from Cochliobolus lunatus is the first fungal cytochrome P450 reported to have 14α-hydroxylase activity. Studies have shown that P-450lun catalyzes the hydroxylation of progesterone (PROG) at C14α with low regiospecificity and activity. To improve its regiospecificity and activity for PROG, truncated forms of P-450lun and its cognate redox partner CPRlun were functionally co-expressed in Escherichia coli. Then, a semi-rational protein engineering approach was applied to P-450lun, resulting in a double-site mutant E109A/F297W with enhanced 14α-position selectivity for PROG compared with the wild-type P-450lun (97% vs. 28%). Protein structure analysis revealed that the F297W substitution can hinder the binding pose for 11β-hydroxylation product formation. Finally, whole-cell catalysis was optimized, and the final titer of 14α-OH-PROG reached 16.0 mg/L. This is the first report where a fungal 14α-hydroxylase was functionally expressed in Escherichia coli. The steroid hydroxylation system obtained in this study can serve as a basis for the synthesis of 14α-hydroxylated PROG and the rapid evolution of eukaryotic cytochrome P-450lun.

Enhancing Escherichia coli abiotic stress resistance through ornithine lipid formation

Escherichia coli is a common host for biotechnology and synthetic biology applications. During growth and fermentation, the microbes are often exposed to stress conditions, such as variations in pH or solvent concentrations. Bacterial membranes play a key role in response to abiotic stresses. Ornithine lipids (OLs) are a group of membrane lipids whose presence and synthesis have been related to stress resistance in bacteria. We wondered if this stress resistance could be transferred to bacteria not encoding the capacity to form OLs in their genome, such as E. coli. In this study, we engineered different E. coli strains to produce unmodified OLs and hydroxylated OLs by expressing the synthetic operon olsFC. Our results showed that OL formation improved pH resistance and increased biomass under phosphate limitation. Transcriptome analysis revealed that OL-forming strains differentially expressed stress- and membrane-related genes. OL-producing strains also showed better growth in the presence of the ionophore carbonyl cyanide 3-chlorophenylhydrazone (CCCP), suggesting reduced proton leakiness in OL-producing strains. Furthermore, our engineered strains showed improved heterologous violacein production at phosphate limitation and also at low pH. Overall, this study demonstrates the potential of engineering the E. coli membrane composition for constructing robust hosts with an increased abiotic stress resistance for biotechnology and synthetic biology applications.Key points• Ornithine lipid production in E. coli increases biomass yield under phosphate limitation.• Engineered strains show an enhanced production phenotype under low pH stress.• Transcriptome analysis and CCCP experiments revealed reduced proton leakage.