Biological Applications Research Articles

The molecular picture of the local environment in a stable model coacervate.

Complex coacervates play essential roles in various biological processes and applications. Although substantial progress has been made in understanding the molecular interactions driving complex coacervation, the mechanisms stabilizing coacervates against coalescence remain experimentally challenging and not fully elucidated. We recently showed that polydiallyldimethylammonium chloride (PDDA) and adenosine triphosphate (ATP) coacervates stabilize upon their transferto deionized (DI) water. Here, we perform molecular dynamics simulations of PDDA-ATP coacervates in supernatant and DI water, to understand the ion dynamics and structure within stable coacervates. We found that transferring the coacervates to DI water results in an immediate ejection of a significant fraction of small ions (Na+ and Cl-) from the surface of the coacervates to DI water. We also observed a notable reduction in the mobility of thesecounterions incoacervates whenin DI water, both in the cluster-forming and slab simulations, together with a lowered displacement of PDDA and ATP. These results suggest that the initial ejection of the ions from the coacervates in DI water may induce an interfacial skin layer formation, inhibiting further mobility of ionsin the skin layer.

Characterization and phylogenetic analysis of the chloroplast genome in Elaeocarpus duclouxii

Elaeocarpus duclouxii, an evergreen tree species, is renowned for its fruits rich in flavonoids exhibiting potent antioxidant properties. Despite its significance, the chloroplast genome of this plant has remained unexplored until now. Our study presents the first comprehensive sequencing and analysis of the E. duclouxii chloroplast genome, revealing a circular DNA molecule of 158,148 base pairs. This genome comprises a large single-copy region of 85,700 base pairs, a small single-copy region of 17,672 base pairs, and a pair of inverted repeat regions totaling 27,388 base pairs. The genome encodes 132 genes, including 87 protein-coding genes, 37 transfer RNA genes, and 8 ribosomal RNA genes. Phylogenetic analyses indicate a close evolutionary relationship between E. duclouxii and E. sylvestris. This study not only represents the first phylogenetic investigation of E. duclouxii but also establishes a crucial genomic foundation for future research area such as conservation genetics, evolutionary biology, and potential biotechnological applications.

Topological and Morphological Membrane Dynamics in Giant Lipid Vesicles Driven by Monoolein Cubosomes

Lipid nanoparticles have important applications as biomedical delivery platforms and broader engineering biology applications in artificial cell technologies. These emerging technologies often require changes in the shape and topology of biological or biomimetic membranes. Here we show that topologically‐active lyotropic liquid crystal nanoparticles (LCNPs) can trigger such transformations in the membranes of giant unilamellar vesicles (GUVs). Monoolein (MO) LCNPs, cubosomes with an internal nanostructure of space group Im3m incorporate into 1,2‐dioleoyl‐sn‐glycero‐3‐phosphocholine (DOPC) GUVs creating excess membrane area with stored curvature stress. Using time‐resolved fluorescence confocal and lattice light sheet microscopy, we observe and characterise various life‐like dynamic events in these GUVs, including growth, division, tubulation, membrane budding and fusion. Our results shed new light on the interactions of LCNPs with bilayer lipid membranes, providing insights relevant to how these nanoparticles might interact with cellular membranes during drug delivery and highlighting their potential as minimal triggers of topological transitions in artificial cells.

Topological and Morphological Membrane Dynamics in Giant Lipid Vesicles Driven by Monoolein Cubosomes.

Lipid nanoparticles have important applications as biomedical delivery platforms and broader engineering biology applications in artificial cell technologies. These emerging technologies often require changes in the shape and topology of biological or biomimetic membranes. Here we show that topologically-active lyotropic liquid crystal nanoparticles (LCNPs) can trigger such transformations in the membranes of giant unilamellar vesicles (GUVs). Monoolein (MO) LCNPs, cubosomes with an internal nanostructure of space group Im3m incorporate into 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) GUVs creating excess membrane area with stored curvature stress. Using time-resolved fluorescence confocal and lattice light sheet microscopy, we observe and characterise various life-like dynamic events in these GUVs, including growth, division, tubulation, membrane budding and fusion. Our results shed new light on the interactions of LCNPs with bilayer lipid membranes, providing insights relevant to how these nanoparticles might interact with cellular membranes during drug delivery and highlighting their potential as minimal triggers of topological transitions in artificial cells.

Comparative analysis of non‐newtonian fluids over an exponentially stretching sheet with convective boundaries

AbstractThe primary objective of this research is to explore the behavior of several non‐Newtonian fluids, including Casson, Williamson, and Maxwell fluids, over an exponentially stretching sheet considering an inclined magnetic field into account. Non‐Newtonian fluids can be encountered in many industrial and biological applications. They differentiate themselves by their sophisticated viscosity and flow properties. For the purpose of optimizing applications like coating technologies, bioengineering, and polymer processing, it is essential to comprehend their flow dynamics. This work illuminates these fluids' behaviors under convective boundary conditions, which is important for numerous industrial processes. Due to the convective boundary conditions, heat transfer at the sheet is affected by the surrounding fluid. The dominating flow field's nonlinear partial differential equations (PDEs) are synthesized into a system of coupled nonlinear ordinary differential equations (ODEs) using appropriate similarity transformations, and the resulting equations are then numerically solved using the BVP4C solver in MATLAB software. To demonstrate the behaviors of velocity, temperature, and concentration, a parametric research has been attempted. Significant parameter's effect on velocity, temperature, concentration, skin friction coefficient, Nusselt number, and Sherwood number have been investigated, and numerical findings are shown graphically. The numerical data is validated to previously published results on a variety of particular instances and found to be in great agreement. For varying values of the porosity parameter, Darcy‐Forchheimer parameter, and magnetic field, the fluid velocity falls. It is claimed that as the Forchheimer number and the porosity parameter expands, the momentum boundary layer thickness and the velocity profile diminishes. Furthermore, at the maximum levels of Schmidt number, the temperature profile rises synchronously, although the concentration profile reflects the flip pattern.

The Role of Liquid Crystal Elastomers in Pioneering Biological Applications

Liquid crystal elastomers have shown an attractive potential for various biological applications due to their unique combination of mechanical flexibility and responsiveness to external stimuli. In this review, we will focus on a few examples of LCEs used with specific applications for biological/biomedical/environmental systems. So far, areas of innovation have been concentrating on the integration of LCEs to enhance stability under physiological conditions, ensure precise integration with biological systems, and address challenges related to optical properties and spatial control of deformation. However, several challenges and limitations must still be addressed to fully realize their potential in biomedical and environmental fields, and future research should focus on continuing to improve biocompatibility, response to the environment and chemical cues, mechanical properties, ensuring long-term stability, and establishing cost-effective production processes. So far, 3D/4D printing appears as a great promise to develop materials of high complexity, almost any shape, and high production output. However, researchers need to find ways to reduce synthesis costs to ensure that LCEs are developed using cost-effective production methods at a scale necessary for their specific applications’ needs.

Rational Fabrication of Functionally-Graded Surfaces for Biological and Biomedical Applications

Rational Fabrication of Functionally-Graded Surfaces for Biological and Biomedical Applications

Heat and mass transfer in tri‐layer ependymal ciliary transport with diverse viscosity

AbstractSpecialized cilia known as ependymal cilia help the cerebrospinal fluid, which is important for nutrient delivery and waste elimination, to circulate in the brain. Many species rely on cilia and flagella for fluid movement and motility. Cilia and flagella, for instance, produce propulsive forces that allow unicellular creatures like Paramecium and Euglena to move through their surroundings. Ciliary transport plays a role in the flow of egg cells, or oocytes, via the fallopian tubes in the female reproductive system. The transfer of the egg towards the uterus is facilitated by the synchronized wave‐like motion produced by the cilia lining the fallopian tubes. Like this, ciliary transport in men aids in the passage of sperm cells via the epididymis. Many scientists and researchers are studying the mechanics of cilia motion and the properties of the viscoelastic fluid layer to develop new treatments and applications in biomedical engineering and for some diseases. Motivated by a wide range of biological applications, the objective of this study is to investigate the heat and mass transfer flow of tri‐layered Newtonian fluids flowing with the help of ciliary beating in a Cartesian coordinate. The fluid is incompressible, and fluid layers are not intermixed. The fluid flow with heat and mass transfer is first modelled in wave and then transmuted into fixed. Solutions for temperature profile, velocity distribution, stresses and concentration distribution are obtained. The influence of incipient parameters is displayed with graphs and plotted with the computational software MATHEMATICA 13.0 in the results section. The key findings obtained from graphs show that the maximum magnitude for temperature and velocity is achieved in the middle layer of fluid whereas in the outer layer concentration profile is maximum. 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.

Hydrogen peroxide luminescent sensors based on rare-earth doped nanocrystals: sensing mechanisms and biological applications

Hydrogen peroxide luminescent sensors based on rare-earth doped nanocrystals: sensing mechanisms and biological applications

Nanoscale Surface Metal-Coating Method without Pretreatment for High-Magnification Biological Observation and Applications.

Biospecimen imaging is essential across various fields. In particular, a considerable amount of research has focused on developing pretreatment techniques, ranging from freeze-drying to the use of highly conductive polymers, and on advancements in instrumentation, such as cryogenic electron microscopy. These specialized techniques and equipment have facilitated nanoscale and microscale bioimaging. However, user access to these environments remains limited. This study introduced a novel technique to achieve high conductivity in bioimaging by employing a magnetically controlled sputtering cathode to facilitate low-temperature deposition and low-electron bombardment. This approach allows for the convenient high-magnification observation of highly structured three-dimensional specimens, such as pill bugs and butterfly wings, and fragile specimens, such as single-cell protozoan parasites, using metal deposition only. Furthermore, it is easily accessible in the field of bioimaging because it does not require any pretreatment and enables surface analysis of biospecimens with an electron microscope using only a single pretreatment process. Protozoa, which are microorganisms, were successfully observed at high magnification without structural changes due to thermal denaturation. Furthermore, metallic film deposition and electrochemical signal measurements using these metallic films were achieved in pill bugs.

Advancing Food Packaging: Exploring Cyto-Toxicity of Shape Memory Polyurethanes

Cytotoxicity is a critical parameter for materials intended for biological applications, such as food packaging. Shape-memory polyurethanes (SMPUs) have garnered significant interest due to their versatile properties and adaptability in synthesis. However, their suitability for biological applications is limited by the use of aromatic isocyanates, such as methylene diphenyl 4,4′-diisocyanate (MDI) and toluene diisocyanate (TDI), which are commonly used in SMPU synthesis but can generate carcinogenic compounds upon degradation. In this study, thermo-responsive shape-memory polyurethanes (SMPUs) were synthesized using poly(tetramethylene ether) glycol (PTMG) and castor oil (CO) as a chain extender with four different isocyanates—aromatic (MDI and TDI), aliphatic (hexamethylene diisocyanate [HDI] and isophorone diisocyanate [IPDI])—to evaluate their impact on polyurethane cytotoxicity. Cytotoxicity assays were conducted on the synthesized SMPU samples before and after exposure to light-induced degradation. The results showed that prior to degradation, all samples exhibited cell proliferation rates above 90%. However, after degradation, the SMPUs containing aromatic isocyanates demonstrated a drastic reduction in cell proliferation to values below 10%, whereas the samples with aliphatic isocyanates maintained cell proliferation above 70%. Subsequently, the influence of polyol chain length was assessed using PTMG, with molecular weights of 1000, 650, and 250 g·mol−1. The results indicated that the SMPUs with longer chain lengths exhibited higher cell proliferation rates both before and after degradation. The thermal and mechanical properties of the SMPUs were further characterized using thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA), and thermomechanical analysis (TMA), providing comprehensive insights into the behavior of these materials.

Water purification and biological efficacy of green synthesized Co/Zn-Doped α-Fe2O3 nanoparticles

In the present study, Co/Zn doped α-Fe2O3 (Hematite) nanoparticles (NPs) were synthesized using polyvinylpyrrolidone (PVP) and Azadirachta indica (AI) leaves aqueous extract. The analytical techniques including XRD, UV, SEM, EDX, VSM, Raman, and FTIR, we were able to identify and characterize the structural, morphological and magnetic attributes of the synthesized NPs. The findings demonstrated that the synthesized NPs exhibit homogeneous spherical shapes with particle sizes ranging from 8.64 to 15.32 nm. The NPs have rhombohedral crystal lattices, with crystallite sizes of 23.25 nm for chemically synthesized doped α-Fe2O3 NPs and 12.52 nm for those synthesized using green methods. The magnetic study has shown that the saturation magnetization (Ms) value of NPs, which ranges from 36 to 45 emu/g at ambient temperature, exhibits superparamagnetic properties (300 K). The treatment of industrial wastewater and its reuse for agricultural purposes are the subjects of the current study. Different concentrations of doped α-Fe2O3 NPs were used as photocatalysts to degrade dyes in a bioreactor under UV light in a heterogeneous mixture. The degradation rates achieved were 96.42 % for Congo Red (CR) and 98.36 % for Eosin Yellow (EY). DPPH assays were conducted to evaluate the antioxidant activity of the synthesized doped α-Fe2O3 NPs. The percentage inhibition of DPPH radicals ranged from 71.13 % to 90.35 %. Our findings indicate that AI leaf extract holds promise as a valuable resource for the development of bioactive compounds and environmentally friendly approaches to synthesizing green NPs. This is primarily attributed to the increased accessibility of bioactive components with potent antioxidant properties. The combination of these benefits provides opportunities for novel uses in environmental cleanup, biological applications, and energy conversion.

Hybrid Nanoparticles Dual‐Loaded With Curcumin and Benzydamine Hydrochloride for the Treatment of Vulvovaginal Candidiasis: From Development to Biological Application In Vitro and In Vivo

Hybrid Nanoparticles Dual‐Loaded With Curcumin and Benzydamine Hydrochloride for the Treatment of Vulvovaginal Candidiasis: From Development to Biological Application In Vitro and In Vivo

Thiolated layered double hydroxide-based nanoparticles: A study on mucoadhesiveness and cytotoxicity

The aim of this study was the synthesis and characterization of thiolated Mg/Al Layered double hydroxide nanoparticles (nLDH) that can adhere to mucosal surfaces. For this purpose, initially, nLDH were synthesized and then their surface was modified with L-cysteine (Cys). Then the Cys-modified nanoparticle structure (nLDHCys) was characterized by FTIR, XRD and FE-SEM/EDS, and the amount of thiol groups was determined using the iodometric method. The cytotoxicity properties of nLDH and LDHCys were examined on cervical (HeLa), fibroblast (L929) and colon (HT29) cell lines. In addition, the adhesion of nanoparticles to mucosal surfaces has been evaluated through mucin interaction experiments and ex vivo tests on ewe vaginal tissue. The results from characterization studies prove that Cys molecule has been successfully modified on the surface of nLDH. Cytotoxicity studies demonstrated that Cys modification did not negatively affect the cell viability, and these results were extremely close to those of nLDH. Ex vivo tests on ewe vaginal tissue and mucin interaction demonstrated that nLDHCys enhanced retention on the mucosal surface. Considering their retention ability to mucosal surface and their biocompatible nature, nLDHCys is expected to play an important role as a promising option for a safe mucoadhesive nanoparticle system for biological applications in the future.

Synthesis of bioactive quercetin-boronate esters as a novel biological agent: Enzyme inhibition, anti-microbial properties, computational insights and anti-cancer activity

This study introduces a novel synthesis for the quercetin-boronate esters (QB1-QB4) for some biological applications. The structure of low-cost, easily synthesized, and functionalizable trigonal planar quercetin-boronate esters was characterized by 1H, 13C, and 11B NMR spectra, FT-IR spectra, UV–Vis spectra, LC-MS/MS spectrometry, elemental analysis, and melting point measurement. Following the successful synthesis studies, quercetin-boronate esters have been tested over glucosidase enzyme inhibition, antimicrobial studies, computational insights, and in vitro anti-cancer activity against pancreatic cancer cells, respectively. QB1 significantly decreased cell viability at a 50 µM concentration compared to other boron compounds. The enzyme inhibition studies on quercetin-boronate esters demonstrated that α-glucosidase enzyme inhibitions were higher than the reference compound. IC50 values of QB1-QB4 against α-glucosidase were 5.92, 5.54, 5.68, and 6.79 μM, repsectivey. As expected, quercetin-boronate esters exhibited respectable activity against the biofilms of some bacteria. The MIC values of QB1-QB4 were 32.5 μg/mL against Enterococcus faecalis. In addition, the binding parameter values and binding sites were determined as a result of docking studies of quercetin-boronate esters. As a result of the scientific findings, quercetin-boronate ester compounds will certainly become important building blocks used in the future from organic synthesis to materials science and medicine.

Organic Materials with Ultrabright Phosphorescence at Room Temperature under Physiological Conditions for Bioimaging.

In contrast to the high efficiency of room temperature phosphorescence in crystal states, the generally utilized nanoparticles of organic materials in bioimaging demonstrated sharply decreased performance by orders of magnitude under physiological conditions, badly limiting the realization of their unique advantages. This case, especially for organic red/near-infrared (NIR) phosphorescence materials, is not only the challenge present in reality but more importantly, for the theoretical problem of deeply understanding and avoiding the quenching effect by oxygen and water toward excited triplet states. Herein, thanks to the intelligent molecular design by the introduction of abundant hydrophobic chains and highly-branched structures, bright and persistent red/NIR phosphorescence under physiological conditions has been realized, which demonstrated the shielding effect towards oxygen, and strengthened the intermolecular interactions to suppress the non-radiative transitions. Accordingly, the record phosphorescence intensity of nanoparticles in bioimage, up to 8.21 ± 0.36 × 108 p s-1 cm-2 sr-1, was achieved, to realize the clear phosphorescence imaging of liver and tumors in living mice, even lymph nodes in rabbit models with high SBRs. This work afforded an efficient way to achieve the bright red/NIR phosphorescence nanoparticles, guiding their further applications in biology and medicine.

Multienzymatic Orthogonal Activation of DNA Codec Enables Tumor-Specific Imaging of Base Excision Repair Activity.

Accurate monitoring of base excision repair (BER) activity in cancer cells is critical for advancing the comprehension of DNA repair processes, gaining insights into cancer development, and guiding treatment strategies. However, current assay techniques for assessing BER activity in cancer cells face challenges due to the heterogeneous origins and diversity of BER enzymes. In this work, we present a highly reliable triple loop-interlocked DNA codec (GATED) that enables precise assessment of BER activity in cancer cells through signal amplification mediated by multienzyme orthogonal activation. The GATED device features a dumbbell-shaped DNA probe to encode two BER enzymes for BER-related signal conversion as well as two bound circular DNA to decode the apurinic/apyrimidinic sites for apurinic/apyrimidinic endonuclease 1 (APE1)-mediated signal amplification. Importantly, GATED is orthogonally activated by multiple target BER enzymes (i.e., uracil DNA glycosylase, thymine DNA glycosylase, and APE1), resulting in a unified fluorescent signal that significantly improves the detection specificity and sensitivity to BER enzymes. Additionally, we demonstrate that the GATED has exceptional biostability within complex biological systems, where it was successfully employed to monitor BER activity in cancer cells with high specificity and enabled cell-based high-throughput screening for BER inhibitors. The GATED provides a much-needed tool for the real-time monitoring of BER activity and the screening of BER inhibitors in cancer cells, potentially advancing both the investigation and clinical application of BER biology.

Synergistic effects of bacteria, enzymes, and cyclic mechanical stresses on the bond strength of composite restorations

Predicting how tooth and dental material bonds perform in the mouth requires a deep understanding of degrading factors. Yet, this understanding is incomplete, leading to significant uncertainties in designing and evaluating new dental adhesives. The durability of dental bonding interfaces in the oral microenvironment is compromised by bacterial acids, salivary enzymes, and masticatory fatigue. These factors degrade the bond between dental resins and tooth surfaces, making the strength of these bonds difficult to predict. Traditionally studied separately, a combined kinetic analysis of these interactions could enhance our understanding and improvement of dental adhesive durability. To address this issue, we developed and validated an original model to evaluate the bond strength of dental restorations using realistic environments that consider the different mechanical, chemical, and biological degradative challenges working simultaneously: bacteria, salivary esterases, and cyclic loading. We herein describe a comprehensive investigation on dissociating the factors that degrade the bond strength of dental restorations. Our results showed that cariogenic bacteria are the number one factor contributing to the degradation of the bonded interface, followed by cyclic loading and salivary esterases. When tested in combinatorial mode, negative and positive synergies towards the degradation of the interface were observed. Masticatory loads (i.e., cycling loading) enhanced the lactic acid bacterial production and the area occupied by the biofilm at the bonding interface, resulting in more damage at the interface and a reduction of 73 % in bond strength compared to no-degraded samples. Salivary enzymes also produced bond degradation caused by changes in the chemical composition of the resin/adhesive. However, the degradation rates are slowed compared to the bacteria and cyclic loading. These results demonstrate that our synergetic model could guide the design of new dental adhesives for biological applications without laborious trial-and-error experimentation.

Heteroleptic complexes of hydrazone Scaffold of picolinoyl N- oxide and 2,4 dihydroxy phenyl moieties; evaluation of antioxidant activity, DNA and protein binding properties and in vitro antiproliferation studies

The present study deals with design and synthesis of new mononuclear Cu(II), Co(II), Ni(II) and Zn(II) metal complexes of hydrazone of 2-(2-(2,4-dihydroxybenzylidene)hydrazinecarbonyl)pyridine-1-oxide (H2L), in a view to study their potential relevance for the biological applications. Structural aspects of the title compound (H2L) and metal complexes synthesized were evaluated by spectral and analytical methods viz. 1H NMR, 13C NMR, LC-MS, FT-IR, UV–Visible, SEM, EDX, Powder XRD, ESR, TGA and DTA. Ligational properties of H2L were explored by employing pH metric equilibrium studies for recognizing metal ion binding potential donor sites, and further HyperChem 7.5 software for computing properties of frontier molecular orbitals to ascertain orientation of highest occupied molecular orbitals from which presumably electrons are donated to metal ion in complex formation. The affinity of all title compounds to bind with CT-DNA and the type of interaction, therein have been studied by conducting UV–VIS absorption and fluorescence emission titrations. The protein-binding ability of all metal complexes with two serum proteins (BSA and HSA) were explored by absorption titrations, and further fluorescence titrations for BSA binding were also performed. Antioxidant activity of the title compounds was carried out by the method of free radical scavenging using spectrophotometric technique. Additionally, cytotoxicity of all metal complexes and ligand was measured by CTG cell proliferation assay after treating them with MDA-MB-231 and SKOV-3 cell lines. The cell cycle arrest and apoptosis assay in above cell lines after treatment with title compounds were also investigated by flow cytometry. In addition, molecular docking studies at target CDK2 protein inferred binding affinity of the title compounds through non covalent bonding interactions.

G4LDB 3.0: a database for discovering and studying G-quadruplex and i-motif ligands.

Non-canonical nucleic acid structures, such as G-quadruplex (G4) and i-Motif (iM), have garnered significant research interest because of their unique structural properties and biological activities. Thousands of small molecules targeting G4/iM structures have been developed for various chemical and biological applications. In response to the growing interest in G4-targeting ligands, we launched the first G4 Ligand Database (G4LDB) in 2013. Here, we introduce G4LDB 3.0 (http://www.g4ldb.com), an upgraded version featuring extensive enhancements in content and functionality. The new version includes over 4800 G4/iM ligands and approximately 51 000 activity entries. Key upgrades include advanced search capabilities, dynamic knowledge graphs, enhanced data visualization, along with a new dynamic analysis function that automatically displays ligand structure clustering results and chemical space distribution. With these updates, G4LDB 3.0 further evolves into a comprehensive resource and valuable research tool. The significant improvements address the increasing demand for efficient data handling and user experience, highlighting the critical role of G4LDB in advancing research on G-quadruplexes and i-motifs.