Effect of Gold Nanoparticles on the Conformation of Bovine Serum Albumin: Insights from CD Spectroscopic Analysis and Molecular Dynamics Simulations.

With the development of nanotechnology, there is growing interest in using nanoparticles (NPs) for biomedical applications, such as diagnostics, drug delivery, imaging, and nanomedicine. The protein's structural stability plays a pivotal role in its functionality, and any alteration in this structure can have significant implications, including disease progression. Herein, we performed a combined experimental and computational study of the effect of gold NPs with a diameter of 5 nm (5 nm Au-NPs) on the structural stability of bovine serum albumin (BSA) protein in the absence and presence of NaCl salt.

Effect of Acetonitrile on the Conformation of Bovine Serum Albumin.

The use of organic solvents in drug delivery systems (DDSs) either to produce albumin nanoparticles or to manipulate the binding of target molecules to albumin, a promising nanocarrier material, presents challenges due to the conformational changes induced in the protein. In this study, we investigated the alterations in the conformation of bovine serum albumin (BSA) caused by acetonitrile (ACN) in aqueous solution by using a combination of spectroscopic analysis and molecular dynamics (MD) simulations. Ultraviolet (UV) absorption, fluorescence, and infrared (IR) absorption spectroscopy were used to analyze the BSA conformation in the solutions containing 0-60 vol % ACN.

Polyethylene microplastics affect behavioural, oxidative stress, and molecular responses in the model.

The escalating presence of microplastic pollution poses a significant environmental threat, with far-reaching implications for both ecosystems and human health. This study investigated the toxicological impact of polyethylene microplastics (PE MPs) using , fruit flies, as a model organism. were exposed to PE MPs orally at concentrations of 1 mg ml and 10 mg ml agar food.

Development of a visible to 1600 nm hyperspectral imaging rigid-scope system using supercontinuum light and an acousto-optic tunable filter.

In this study, we developed a rigid-scope system that can perform hyperspectral imaging (HSI) between visible and 1600 nm wavelengths using a supercontinuum light source and an acousto-optic tunable filter to emit specific wavelengths. The system optical performance was verified, and the classification ability was investigated. Consequently, it was demonstrated that HSI (490-1600 nm) could be performed.

Pixel Screening in Lifetime-Based Temperature Mapping Using β-NaYF:Nd,Yb by Time-Gated Near-Infrared Fluorescence Imaging on Deep Tissue in Live Mice.

Near-infrared fluorescence (NIRF) thermometry is an emerging method for the noncontact measurement of deep temperatures. Fluorescence-lifetime-based methods are effective because they are unaffected by optical loss due to excitation or detection paths. Moreover, the physiological changes in body temperature in deep tissues and their pharmacological effects are yet to be fully explored.

Temperature imaging inside fluid devices using a ratiometric near infrared (NIR-II/III) fluorescent YO: Nd, Yb, Er nanothermometer.

Luminescence thermometry is a non-contact method that can measure surface temperatures and the temperature of the area where the fluorescent probe is located, allowing temperature distribution visualizations with a camera. Ratiometric fluorescence thermometry, which uses the intensity ratio of fluorescence peaks at two wavelengths with different fluorescence intensity dependencies, is an excellent method for visualizing temperature distributions independent of the fluorophore spatial concentration, excitation light intensity and absolute fluorescence intensity. Herein, Nd/Yb/Er-doped YO nanomaterials with a diameter of 200 nm were prepared as phosphors for temperature distribution measurement of fluids at different temperatures.

Visualization of hydrocarbon chain length and degree of saturation of fatty acids in mouse livers by combining near-infrared hyperspectral imaging and machine learning.

Fatty acids play various physiological roles owing to their diverse structural characteristics, such as hydrocarbon chain length (HCL) and degree of saturation (DS). Although the distribution of fatty acids in biological tissues is associated with lipid metabolism, in situ imaging tools are still lacking for HCL and DS. Here, we introduce a framework of near-infrared (1000-1400 nm) hyperspectral label-free imaging with machine learning analysis of the fatty acid HCL and DS distribution in the liver at each pixel, in addition to the previously reported total lipid content.

Infrared spectroscopy analysis determining secondary structure change in albumin by cerium oxide nanoparticles.

Cerium oxide (CeO) nanoparticles are expected to have applications in the biomedical field because of their antioxidative properties. Inorganic nanoparticles interact with proteins at the nanoparticle surface and change their conformation when administered; however, the principle underlying this interaction is still unclear. This study aimed to investigate the secondary structural changes occurring in bovine serum albumin (BSA) mixed with CeO nanoparticles having different surface modifications using Fourier transform infrared spectroscopy.

Enhancing near-infrared fluorescence intensity and stability of PLGA-b-PEG micelles by introducing Gd-DOTA at the core boundary.

Micelles have been extensively used in biomedicine as potential carriers of hydrophobic fluorescent dyes. Their small diameters can potentially enable them to evade recognition by the reticuloendothelial system, resulting in prolonged circulation. Nevertheless, their lack of stability in physiological environments limits the imaging utility of micelles.

Evaluating the identification of the extent of gastric cancer by over-1000 nm near-infrared hyperspectral imaging using surgical specimens.

Significance: Determining the extent of gastric cancer (GC) is necessary for evaluating the gastrectomy margin for GC. Additionally, determining the extent of the GC that is not exposed to the mucosal surface remains difficult. However, near-infrared (NIR) can penetrate mucosal tissues highly efficiently.

Controlling Molecular Dye Encapsulation in the Hydrophobic Core of Core-Shell Nanoparticles for In Vivo Imaging.

Polymeric nanoparticles with a hydrophobic core are valuable biomedical materials with potential applications in in vivo imaging and drug delivery. These materials are effective at protecting vulnerable molecules, enabling them to serve their functions in hydrophilic physiological environments; however, strategies that allow the chemical composition and molecular weight of polymers to be tuned, forming nanoparticles to control the functional molecules, are lacking. In this article, we review strategies for designing core-shell nanoparticles that enable the effective and stable encapsulation of functional molecules for biomedical applications.

Influence of Carboxyl Group Ratios on the Design of Breast Cancer Targeting Bimodal MR/NIR-II Imaging Probe from PLGA@Gd-DOTA@PEG Micelles Conjugating Herceptin.

We developed a small MRI/NIR-II probe to target HER2 (tetanucleotide) breast cancer cells. The probe is composed of PLGA--PEG micelles encapsulated NIR-II, and Gd-DOTA is conjugated at the border of PLGA/PEG. Herceptin was then conjugated to carboxyl residues of PLGA--PEG chains.

Effect of carbonaceous ultrafine particles on the structure and oligomerization of Aβ peptide.

The impact of pervasive air pollutants on human health is a growing concern in scientific communities. Among different air pollutants, ultrafine particles (UFPs; with aerodynamic diameter <100 nm) might pass through biological barriers and have a severe impact on human health, including early progression of neurodegenerative diseases such as Alzheimer's disease (AD). A significant fraction of UFPs consists of carbonaceous compounds, composed of elemental and organic carbon (EC and OC).

The effect of Gd-DOTA locations within PLGA--PEG micelle encapsulated IR-1061 on bimodal over-1000 nm near-infrared fluorescence and magnetic resonance imaging.

Multimodal imaging is attractive in biomedical research because it can provide multidimensional information about objects that individual techniques cannot accomplish. In particular, combining over one-thousand-nanometer near-infrared (OTN-NIR) fluorescence and magnetic resonance (MR) imaging is promising for detecting lesions with high sensitivity and structural information. Herein, we describe the development of a bimodal OTN-NIR/MRI probe from gadolinium-tetraazacyclododecanetetraacetic acid (Gd-DOTA) conjugated poly(lactic--glycolic acid)--poly(ethylene glycol) copolymer (PLGA--PEG) micelle encapsulated IR-1061 at two different locations.

Effects of music exposure during pregnancy on maternal behavior in mother rats.

Several studies have demonstrated the possibility of positive effects of exposure to music during pregnancy on mental function in humans and animals. Although there remains a core belief in the positive effects of music during pregnancy, the underlying neurobehavioral mechanisms of these effects remain unknown. In this study, we aimed to clarify the relationship between maternal nurturing behavior and the oxytocinergic system to elucidate the effect of music on mental health during pregnancy in an experimental investigation using animal models.

Changes in the Secondary Structure and Assembly of Proteins on Fluoride Ceramic (CeF) Nanoparticle Surfaces.

Fluoride nanoparticles (NPs) are materials utilized in the biomedical field for applications including imaging of the brain. Their interactions with biological systems and molecules are being investigated, but the mechanism underlying these interactions remains unclear. We focused on possible changes in the secondary structure and aggregation state of proteins on the surface of NPs and investigated the principle underlying the changes using the amyloid β peptide (Aβ) based on infrared spectrometry.

Designing highly emissive over-1000 nm near-infrared fluorescent dye-loaded polystyrene-based nanoparticles for deep imaging.

Polystyrene-based nanoparticles (PSt NPs) prepared by emulsion polymerization are promising organic matrices for encapsulating over-thousand-nanometer near-infrared (OTN-NIR) fluorescent dyes, such as thiopyrilium IR-1061, for OTN-NIR dynamic live imaging. Herein, we propose an effective approach to obtain highly emissive OTN-NIR fluorescent PSt NPs (OTN-PSt NPs) in which the polarity of the PSt NPs was adjusted by changing the monomer ratio (styrene to acrylic acid) in the PSt NPs and the dimethyl sulfoxide concentration in the IR-1061 loading process. Moreover, OTN-PSt NPs covalently modified with poly(ethylene glycol) (PEG) (OTN-PSt-PEG NPs) showed high dispersion stability under physiological conditions and minimal cytotoxicity.

Effect of the enantiomeric structure of hydrophobic polymers on the encapsulation properties of a second near infrared (NIR-II) fluorescent dye for deep imaging.

Over-thousand-nanometer (OTN) near-infrared (NIR) fluorophores are useful for biological deep imaging because of the reduced absorption and scattering of OTN-NIR light in biological tissues. IR-1061, an OTN-NIR fluorescent dye, has a hydrophobic and cationic backbone in its molecular structure, and a non-polar counter ion, BF . Because of its hydrophobicity, IR-1061 needs to be encapsulated in a hydrophobic microenvironment, such as a hydrophobic core of polymer micelles, shielded with a hydrophilic shell for bioimaging applications.

Design, Synthesis, and Anticancer Activity of Triptycene-Peptide Hybrids that Induce Paraptotic Cell Death in Cancer Cells.

We report on the design and synthesis of triptycene-peptide hybrids (TPHs), , -, and -, which are conjugates of a triptycene core unit with two or three cationic KKKGG peptides (K: lysine and G: glycine) through a C alkyl chain. It was discovered that - and - induce paraptosis, a type of programmed cell death (PCD), in Jurkat cells (leukemia T-lymphocytes). Mechanistic studies indicate that these TPHs induce the transfer of Ca from the endoplasmic reticulum (ER) to mitochondria, a loss of mitochondrial membrane potential (ΔΨ), tethering of the ER and mitochondria, and cytoplasmic vacuolization in the paraptosis processes.

Induction of Paraptosis by Cyclometalated Iridium Complex-Peptide Hybrids and CGP37157 via a Mitochondrial Ca Overload Triggered by Membrane Fusion between Mitochondria and the Endoplasmic Reticulum.

We previously reported that a cyclometalated iridium (Ir) complex-peptide hybrid (IPH) functionalized with a cationic KKKGG peptide unit on the 2-phenylpyridine ligand induces paraptosis, a relatively newly found programmed cell death, in cancer cells (Jurkat cells) via the direct transport of calcium (Ca) from the endoplasmic reticulum (ER) to mitochondria. Here, we describe that CGP37157, an inhibitor of a mitochondrial sodium (Na)/Ca exchanger, induces paraptosis in Jurkat cells via intracellular pathways similar to those induced by . The findings allow us to suggest that the induction of paraptosis by and CGP37157 is associated with membrane fusion between mitochondria and the ER, subsequent Ca influx from the ER to mitochondria, and a decrease in the mitochondrial membrane potential ().

Effect of Carbon Black Nanoparticle on Neonatal Lymphoid Tissues Depending on the Gestational Period of Exposure in Mice.

Particulate air pollution, containing nanoparticles, enhances the risk of pediatric allergic diseases that is potentially associated with disruption of neonatal immune system. Previous studies have revealed that maternal exposure to carbon black nanoparticles (CB-NP) disturbs the development of the lymphoid tissues in newborns. Interestingly, the CB-NP-induced immune profiles were observed to be different depending on the gestational period of exposure.

Effects of Prenatal Exposure to Titanium Dioxide Nanoparticles on DNA Methylation and Gene Expression Profile in the Mouse Brain.

Titanium dioxide nanoparticles (TiO-NP) are important materials used in commercial practice. Reportedly, TiO-NP exposure during pregnancy can affect the development of the central nervous system in mouse offspring; however, the underlying mechanism remains unknown. In the present study, we investigated the impact of prenatal TiO-NP exposure on global DNA methylation and mRNA expression patterns in the brains of neonatal mice.

Effects of hydrophilic/hydrophobic blocks ratio of PEG-b-PLGA on emission intensity and stability of over-1000 nm near-infrared (NIR-II) fluorescence dye-loaded polymeric micellar nanoparticles.

Polymeric micellar nanoparticles (PNPs) composed of an amphiphilic block copolymer formed from hydrophilic and hydrophobic blocks and over-thousand-nanometer (OTN) near-infrared (NIR) fluorescent dye are promising fluorophores for the dynamic imaging of deep tissue. In this study, we examined the effect of the ratio of hydrophilic/hydrophobic blocks of a block copolymer, poly(ethylene glycol) (PEG)-b-poly(lactide-co-glycolide) (PLGA), on the properties of OTN-PNPs encapsulating IR-1061. OTN-PNPs with a higher molecular weight of PLGA cores showed higher emission and stabilities under physiological conditions.