Biological Environment Research Articles

Protein Precoating with Concentration-Dependent Manner Breaks through the Biomacromolecular Barrier of Transferrin-Functionalized Nanoparticle in Intestinal Mucosa.

Biomacromolecules in physiological environments would adsorb onto the nanoparticles (NPs) to form corona layers, in which protein coronas (PCs) are the major constituent. PCs always play diverse influences on the fate of NPs in vitro and in vivo, especially for active-targeting NPs (e.g., transferrin-modified nanoparticles, Tf-NP). In order to eliminate the inhibition of PCs on the efficiency of Tf-NP, the precoated Tf-NP with bovine serum albumin (BSA, B@Tf-NP) was designed to fabricate an "active PCs" (PCs formed by artificial modification) against the "passive PCs" (PCs formed in the biological environments), which was inspired by the formation pattern of PCs. The results indicated that B@Tf-NP had similar particle size, dispersion, and physical stability with Tf-NP. Surprisingly, B@Tf-NP enhanced the cellular uptake in enterocytes and permeability in intestinal tract of mice. Notably, the concentration ratio of BSA to Tf that could ensure Tf revealed timely during the interacted process was considered to be appropriate. These findings provide an easy while efficient design platform for active-targeting NPs to overcome the biomacromolecular barrier in oral administration.

Surface Modification of Bioactive Glasses by Femtosecond and CO2 Lasers

This study explores the potential of laser surface modification (LSM) to enhance the biological properties of melt-derived bioactive glasses, specifically 45S5 and ICIE16, which are key in medical implants due to their bone-regenerating capabilities. Despite their bioactivity, these materials have limitations in cellular adhesion due to their smooth surfaces. LSM enables the creation of precise surface patterns that could improve interactions with biological environments. This study involved surface texturing bioactive glass (BG) samples using CO2 and femtosecond (fs) laser systems, modifying the laser average power, scanning speed, line spacing, and number of passes. Characterization methods included optical and stereoscopic microscopy, profilometry, and solubility tests in Tris-HCl buffer to evaluate surface roughness evolution, morphology, and bioactive behavior. The findings demonstrated significant modifications in surface properties post-texturing. The CO2 laser-treated surfaces preserve the increased roughness values after 75 days of immersion in Tris-HCl buffer for both 45S5 and ICIE16 melt-quenched bioactive glasses, showing a potential long-term osteoconductivity enhancement. On the contrary, the femtosecond laser-treated surfaces revealed a preferential apatite precipitation ability at the pattern grooves. Femtosecond laser modification stands as a suitable technique to provide preferential osteoconductivity characteristics when conducted on the surface of bioactive glass with moderate reactivity, such as ICIE16 bioactive glass.

Rapid restoration of potent neutralization activity against the latest Omicron variant JN.1 via AI rational design and antibody engineering

The rapid evolution of the viral genome has led to the continual generation of new variants of SARS-CoV-2. Developing antibody drugs with broad-spectrum and high efficiency is a long-term task. It is promising but challenging to develop therapeutic neutralizing antibodies (nAbs) through in vitro evolution based on antigen-antibody binding interactions. From an early B cell antibody repertoire, we isolated antibody 8G3 that retains its nonregressive neutralizing activity against Omicron BA.1 and various other strains in vitro. 8G3 protected ACE2 transgenic mice from BA.1 and WA1/2020 virus infection without adverse clinical manifestations and completely cleared viral load in the lungs. Similar to most IGHV3-53 antibodies, the binding sites of 8G3 and ACE2 largely overlap, enabling competition with ACE2 for binding to RBD. By comprehensively considering the binding free energy changes of the antigen-antibody complexes, the biological environment of their interactions, and the evolutionary direction of the antibodies, we were able to select 50 mutants. Among them, 11 were validated by experiments showing better neutralizing activities. Further, a combination of four mutations were identified in 8G3 that increased its neutralization potency against JN.1, the latest Omicron mutant, by approximately 1,500-fold, and one of the mutations led to an improvement in activity against multiple variants to a certain extent. Together, we established a procedure of rapid selection of neutralizing antibodies with potent SARS-CoV-2 neutralization activity. Our results provide a reference for engineering neutralizing antibodies against future SARS-CoV-2 variants and even other pandemic viruses.

Responsive nanomaterials in biomedicine, patent path and prospect analysis

In recent years, responsive nanomaterials have demonstrated tremendous potential in biomedical applications due to their unique advantages in precise drug delivery and controlled release. For complex diseases such as cancer, chronic inflammation, and genetic disorders, traditional treatment methods are often limited by insufficient targeting and significant side effects. Responsive nanotechnology, by sensing specific internal or external stimuli, has significantly enhanced the precision and efficiency of treatments. This study systematically summarizes the technological trajectory and emerging research directions of responsive nanomaterials through global patent and literature data, employing main path analysis, derivative path analysis, and keyword co-occurrence analysis. The results reveal the evolution of this field, from the optimization of early single-stimulus-responsive nano delivery systems to the rise of theranostics integration, followed by advancements in multi-stimuli-responsive synergistic therapies, and finally, the innovation in biomimetic material design. Each developmental phase has increasingly focused on adapting to complex biological environments, achieving superior targeting performance, and enhancing therapeutic efficacy. Keyword co-occurrence analysis highlights key research hotspots, including biomimetic design, multimodal synergistic therapies, and emerging response mechanisms. In the future, responsive nanomaterials are expected to play a pivotal role in personalized medicine, multifunctional carrier design, and complex disease management, providing novel insights and technological support for precision medicine.

Chemical Engineering of DNAzyme for Effective Biosensing and Gene Therapy.

RNA-cleaving DNAzymes are in vitro selected functional nucleic acids with inherent catalytic activities. Due to their unique properties, such as high specificity, substrate cleavage capability, and programmability, DNAzymes have emerged as powerful tools in the fields of analytical chemistry, chemical biology, and biomedicine. Nevertheless, the biological applications of DNAzymes are still impeded by several challenges, such as structural instability, compromised catalytic activity in biological environments and the lack of spatiotemporal control designs, which may result in false-positive signals, limited efficacy or non-specific activation associated with side effects. To address these challenges, various strategies have been explored to regulate DNAzyme activity through chemical modifications, enhancing their stability, selectivity, and functionality, thereby positioning them as ideal candidates for biological applications. In this review, a comprehensive overview of chemically modified DNAzymes is provided, discussing modification strategies and the effects of these modifications on DNAzymes. Specific examples of the use of chemically modified DNAzymes in biosensing and gene therapy are also presented and discussed. Finally, the current challenges in the field are addressed and offer perspectives on the potential direction for chemically modified DNAzymes.

Insight into the Various Synthetic Approaches of 1,3,4 and 1,2,4- Oxadiazole and its Derivatives, along with their Remarkable Biological Activities

Oxadiazole is an organic compound featuring a heterocyclic ring housing carbon, oxygen, and nitrogen atoms. Due to their heightened stability in biological environments, oxadiazole rings exhibit significant biological activities, effectively addressing health challenges like infectious diseases and chronic conditions in medicinal chemistry. The main objective of this review is to discuss various synthetic approaches related to oxadiazole and its derivatives, along with their biological activities. The diverse reactivity positions oxadiazole as a valuable building block in organic synthesis, with derivatives exhibiting promising pharmacological activities. It involves a systematic literature review, critical analysis, and synthesis of existing research This review comprises the everexpanding chemical knowledge but also holds significant implications for drug development. The various synthetic approaches, such as Suzuki-Miyaura, Stille coupling [3+2] cycloaddition reaction, and many more methods used for the synthesis of oxadiazole through different schemes, have been discussed thoroughly. This review also concisely associated the pharmacological activities of new oxadiazole and its derivatives, such as prenoxdiazine, dapagliflozin, nesapidil, pleconaril, and so on. This review highlights the importance of continued research into the structure-activity relationships of oxadiazole derivatives, paving the way for developing novel and more potent therapeutic agents.

Influences of multi-pass friction stir alloying on characterization of AZ91D alloy-based dual reinforcement bio-ceramic nano-composites.

In current study, microstructural, mechanical and corrosion behaviour were investigated with incorporation of dual reinforced AZ91D surface composites. This research was carried out for enhancement of the bio-degradability in biological environment. The surface composites were successfully fabricated by friction stir processing method with a rotation speed of 800 rpm, travel speed of 80 mm/min and 2.5° tilt angle at multi-passes. The surface properties were characterized via optical, SEM, EDS, XRD and EBSD techniques. The microstructure showed that the reinforcements were equally distributed into the surface matrix after 3-passes for sets of composites. After 3-passes FSP average grain diameter of the composite C (1.61 μm) was smaller than that of composite A (1.86 μm) and composite B (1.63 μm), because of the strong shear deformation and generated friction heat, which occurred via dynamic recrystallization between grains in the processed zones. The microhardness of Composite C (162 Hv) has a higher than the composite A (125.2 Hv) and composite B (146.2 Hv). The ultimate tensile strength of composite A (152.7 MPa) was greater than that of composite B (133 MPa) and composite C (111.3 MPa). Furthermore, the corrosion resistance at 7, 15 and 30 days of immersion of composite C was higher than that of composite A and composite B, because of the domino effects and better bio-mineralization with the addition of Y2O3 and ZrO2 particles. The typically worn surface revealed reduced deep pits, pits and cracks due to better ionization of the hydrogen generated during immersion. Finally, this research was carried out for treatment of bone defects and fractures as well as improving corrosion resistance of the mg-containing biocompatible implants.

Peptide Fluorescent Probes Based on Aggregation-Induced Emission for the Detection of Ni2+ and Zn2+ in Different Buffer Systems.

Heavy metal contamination has emerged as a significant global environmental concern. The contamination of Ni2+ and Zn2+ has attracted increasing attention, not only because of the pollution it causes but also because of the potential risks it poses to human health. It is of great importance to explore sensitive and rapid analytical methods for the accurate detection of Ni2+ and Zn2+. This paper presents the design and synthesis of a peptide fluorescent probe, TPE-HN (TPE-Pro-Trp-His-Glu-Phe-Gln-NH2), coupled with a peptide to tetraphenylethylene (TPE). The aggregation-induced emission (AIE) effect has been employed to construct a rapid 'turn-on' assay for Ni2+and Zn2+ peptide fluorescent probes. The probe is capable of qualitatively detecting Ni2+ and Zn2+ in different buffer systems and can be distinguished by changes in buffer systems. The limit of detection for Ni2+ and Zn2+ in a 15% buffer solution was 9.613 mM (R2 = 0.9924), whereas the limit of detection for Ni2+ in a 20% buffer solution was 1.215 mM (R2 = 0.9922). The probe exhibits high sensitivity, high cell permeability and low biotoxicity, rendering it suitable for live-cell imaging under biological conditions. This demonstrates that TPE-HN is capable of detecting Ni2+ and Zn2+ in biological environments.

Directing mineralization of ZnO nanoparticles in cyanobacterial liquid crystalline polysaccharides for cancer therapies.

Effective cancer therapy faces significant challenges, including non-selective toxicity, limited structural stability, inconsistent nanoparticle (NP) morphology, and instability under varying biological conditions. These issues hindering targeted delivery and therapeutic efficacy. Previous approaches using polysaccharide-based nanomaterials have shown promise; however, problems such as inconsistent NP sizes and shapes, poor mechanical stability, and limited pH resilience restrict their clinical potential. This study hypothesized that sacran, a cyanobacterial liquid crystalline (LC) polysaccharide, can stabilize ZnO NPs, allowing for controlled mineralization, enhanced stability, and selective cytotoxicity. We developed ZnO nanocomposite xerogels in an LC sacran matrix, yielding block-like ZnO NPs (25-70 nm) with high surface-area-to-volume ratios that improve cellular uptake in tumor environments. Incorporating these NPs into chemically crosslinked sacran matrices resulted in a 3-fold increase in mechanical strength and a 10-fold improvement in swelling capacity compared to physically crosslinked systems. Additionally, the sacran-ZnO nanocomposites demonstrated robust stability under various pH conditions, indicating their resilience in diverse biological environments. Cytotoxicity assays revealed that higher concentrations of ZnO NP selectively increased toxicity toward human lung cancer cells (A549), with less impact on human dermal fibroblasts (HDFa). Moreover, HDFa successfully attached to and proliferated on the smooth surfaces of the xerogels, emphasizing their compatibility with normal cells. This highlights the potential of sacran-ZnO nanocomposite xerogels as cancer-selective therapeutic materials, offering stability and effectiveness even under varying biological conditions, while addressing key challenges associated with earlier NP-based therapies.

The effect of the type of anaesthesia on long-term outcomes after cancer resection surgery: a narrative review.

The peri-operative period may create a biological environment conducive to cancer cell survival and dissemination. Microscopic residual tumours (micrometastases) can be dislodged even with excellent surgical technique. At the same time, the stress response from surgery can temporarily impair immune function and activate inflammatory processes, increasing the risk of tumour proliferation. This narrative review investigates how peri-operative anaesthetic and analgesic interventions may influence cancer recurrence and metastasis by exploring evidence from both experimental and clinical studies. A comprehensive review of the literature was conducted to identify relevant preclinical and clinical studies published. While surgery remains the best curative option for many cancers, metastasis remains the leading cause of death. Numerous studies have suggested that different anaesthetic drugs and techniques could impact cancer outcomes including volatile anaesthetic agents; total intravenous anaesthesia with propofol; local anaesthetics; regional anaesthesia; and opioids. This review focuses on these five commonly used anaesthetic approaches and evaluates their potential impact on cancer progression. There is a complex interplay between anaesthetic and analgesic techniques and cancer outcomes. Despite promising data from laboratory experimental models, the balance of available clinical trials indicates an equivalent influence of all evaluated anaesthetic techniques on long-term oncologic outcomes, except, possibly, for peritumoral or intraperitoneal local anaesthetic infiltration.

Comparative Analysis of Energy Harvesting by Magnetoelectric components in a Simulated Biological Environment

Comparative Analysis of Energy Harvesting by Magnetoelectric components in a Simulated Biological Environment

Comprehensive profiling of serum microRNAs in normal and non-alcoholic fatty liver disease (NAFLD) patients

Pediatric non-alcoholic fatty liver disease (NAFLD) is emerging as a worldwide health concern with the potential to advance to cirrhosis and liver cancer. NAFLD can also directly contribute to heart problems through inflammation and insulin resistance, even in individuals without other risk factors. The pathological mechanisms of NAFLD are linked to functional differences of miRNAs in different biological environments. The miRNA in serum exosomes may reflect the pathological state of the liver and changes in systemic metabolism, while the miRNA in serum may be associated with physiological processes other than the liver. Pediatric non-alcoholic fatty liver disease (NAFLD) is emerging as a worldwide health concern with the potential to advance to cirrhosis and liver cancer. NAFLD can also directly contribute to heart problems through inflammation and insulin resistance, even in individuals without other risk factors. The pathological mechanisms of NAFLD are linked to functional differences of miRNAs in different biological environments. The miRNA in serum exosomes may reflect the pathological state of the liver and changes in systemic metabolism, while the miRNA in serum may be associated with physiological processes other than the liver. Pediatric non-alcoholic fatty liver disease (NAFLD) is emerging as a worldwide health concern with the potential to advance to cirrhosis and liver cancer. NAFLD can also directly contribute to heart problems through inflammation and insulin resistance, even in individuals without other risk factors. The pathological mechanisms of NAFLD are linked to functional differences of miRNAs in different biological environments. The miRNA in serum exosomes may reflect the pathological state of the liver and changes in systemic metabolism, while the miRNA in serum may be associated with physiological processes other than the liver. Our study identified 36 miRNAs with differential expression in the serum of NAFLD patients compared to the control group, including 21 miRNAs with significantly increased expression and 15 with decreased expression. Consistent with our previously reported data on serum-derived exosomal miRNA profiling, this study also observed a notable upregulation of serum miR-122-5p levels in NAFLD patients. PCR validation confirmed the differential expression of miR-122-5p identified through RNA sequencing. Functional analysis using GO and KEGG pathways revealed a diverse range of biological roles associated with these differentially expressed miRNAs. Notably, NAFLD significantly impacts heart health, with miR-122-5p playing a key role in regulating cardiovascular function. Furthermore, activation of the miR-122/Sirt-6/ACE2 axis may contribute to myocardial necrosis, highlighting its potential role in NAFLD-associated cardiovascular risks. Our study suggests that miR-122 plays a key role in the progression of NAFLD and its associated metabolic disturbances, which can increase the risk of cardiovascular disease. Targeting miR-122 may offer potential therapeutic benefits for improving both liver and heart health in individuals with NAFLD.

Evaluating the In Situ Effects of Whole Protein Coronas on the Biosensing of Antibody-Immobilized Nanoparticles Using Two-Color Fluorescence Nanoparticle Tracking Analysis

The formation of protein coronas around engineered nanoparticles (ENPs) in biological environments is critical in nanomedicine, as these coronas significantly influence the biological behavior of ENPs. Despite extensive research on protein coronas, understanding the in situ influence of whole (soft plus hard) protein coronas has remained challenging. In this study, we demonstrate a strategy to assess the in situ effects of whole coronas on the model biosensing of anti-IgG using IgG-conjugated gold nanoparticles (IgG-AuNPs) through fluorescence nanoparticle tracking analysis (F-NTA), which enables the selective tracking of fluorescent particles within complex media. In our approach, anti-IgG and IgG-AuNPs were labeled with distinct fluorescent dyes. The accordance in hydrodynamic diameter distributions observed at two different wavelengths verifies the successful capture of anti-IgG on the IgG-AuNPs. The counting of fluorescent anti-IgG within the size distribution allows for a quantitative assessment of biosensing efficiency. This method was applied to evaluate the effects of four protein coronas—human serum albumin, high-density lipoproteins, immunoglobulin G, and fibrinogen—as well as their mixture across varying incubation times and concentrations. The results suggest that the physical presence of whole protein coronas surrounding the IgG-AuNPs may assist the biosensing interaction in situ rather than screening it.

Evaluation of low-crystallinity apatite as a novel synthetic bone graft material: In vivo and in vitro analysis.

To overcome the shortcomings of sintered bone graft materials, low-crystallinity apatite (LCA) was developed using a non-heated approach to enhance resorption and integration during bone regeneration. This study aimed to evaluate the efficacy of LCA as a synthetic bone graft material for bone reconstruction. LCA was compared to three conventional synthetic bone graft materials: biphasic calcium phosphate (BCP) 37, BCP 64, and octacalcium phosphate (OCP). Crystalline structure and surface morphology were examined using X-ray diffraction (XRD) and scanning electron microscopy (SEM). In vivo testing was conducted using a rabbit calvarial augmentation model, in which the grafts were placed into standardized defects. Bone formation and graft resorption were analyzed using micro-computed tomography (micro-CT) and histomorphometric analyses at three and six weeks post-implantation. LCA exhibited structural similarities to the allograft material and enhanced surface properties. Micro-CT and histomorphometric evaluations at three and six weeks post-implantation demonstrated higher rates of bone formation and substantial volumetric changes with LCA, indicating efficient graft resorption and bone regeneration. LCA exhibited superior integration, osteoconductivity, and biodegradability compared to other synthetic grafts, suggesting the potential for improved clinical outcomes with its use. Although the efficacy of LCA has been validated, further studies in diverse biological environments are necessary to confirm its safety and effectiveness for broader clinical use. LCA, which mimics natural bone structure and has superior integration and osteoconductivity, has the potential for clinical applications requiring rapid and effective bone healing.

Rapid synthesis of manganese dioxide nanoparticles for enhanced biocompatibility and theranostic applications.

Manganese dioxide (MnO2), lauded for its biocompatibility and distinctive optical and physical characteristics, has become an indispensable material in the biomedical field, showing immense potential in disease detection, treatment, and prevention. Particularly, the ability of MnO2 nanoparticles to oxidize glutathione (GSH) to its oxidized form has positioned them as pivotal players in GSH sensing. However, conventional preparation methods, whether top-down or bottom-up, often result in nanoparticles that require multi-step processing and modification to achieve good dispersion in physiological conditions, which is both time-consuming and complex. To address this, a rapid and efficient method was developed for producing well-dispersed and stable MnO2 nanoparticles using tannic acid to reduce potassium permanganate. The polyphenolic structure of tannic acid not only facilitates the reduction process but also enhances the dispersibility of the nanoparticles in biological environments. In addition, PEG could improve the stability of MnO2 nanoparticles and also reduce their size. Moreover, we demonstrate the application of these nanoparticles in a colorimetric assay for GSH detection, leveraging their ability to react with GSH to produce Mn2+. Furthermore, these nanoparticles were utilized in a colorimetric assay for GSH detection, harnessing their reactivity with GSH to generate Mn2+. Beyond this, the MnO2 nanoparticles exhibit potential for the loading of a spectrum of molecules, including small molecules, peptides, DNA, RNA, and proteins, through electrostatic interactions, π-π stacking, and the inherent reactivity of polyphenols. This groundbreaking strategy heralds a new era for MnO2 in the realm of theranostic agent delivery, offering a promising avenue for enhancing diagnostic accuracy and therapeutic efficacy in biomedical applications.

Self-Foldable Three-Dimensional Biointerfaces by Strain Engineering of Two-Dimensional Layered Materials on Polymers.

Two-dimensional layered materials (2DLMs) have received increasing attention for their potential in bioelectronics due to their favorable electrical, optical, and mechanical properties. The transformation of the planar structures of 2DLMs into complex 3D shapes is a key strategic step toward creating conformal biointerfaces with cells and applying them as scaffolds to simultaneously guide their growth to tissues and enable integrated bioelectronic monitoring. Using a strain-engineered self-foldable bilayer, we demonstrate the facile formation of predetermined 3D microstructures of 2DLMs with controllable curvatures, called microrolls. Three types of 2DLM microrolls─graphene, hexagonal boron nitride, and molybdenum disulfide─provide scaffolds to encapsulate and organize human-induced pluripotent stem cell-derived cardiomyocytes into tubular aggregates. Encapsulating cardiomyocytes in porous 2DLMs-laden microrolls allows for real-time microscopic observation and construction of precisely shaped cardiac tissues interacting with their surroundings. The ability to combine 2DLMs of diverse properties in the same structure further demonstrates the potential of this self-folding strategy for creating flexible, ultrathin bioelectronic devices that integrate seamlessly with complex biological environments, offering real-time, noninvasive monitoring of engineered tissues and organoids.

Leveraging Network Target Theory for Efficient Prediction of Drug-Disease Interactions: A Transfer Learning Approach.

Efficient virtual screening methods can expedite drug discovery and facilitate the development of innovative therapeutics. This study presents a novel transfer learning model based on network target theory, integrating deep learning techniques with diverse biological molecular networks to predict drug-disease interactions. By incorporating network techniques that leverage vast existing knowledge, the approach enables the extraction of more precise and informative drug features, resulting in the identification of 88,161 drug-disease interactions involving 7,940 drugs and 2,986 diseases. Furthermore, this model effectively addresses the challenge of balancing large-scale positive and negative samples, leading to improved performance across various evaluation metrics such as an Area under curve (AUC) of 0.9298 and an F1 score of 0.6316. Moreover, the algorithm accurately predicts drug combinations and achieves an F1 score of 0.7746 after fine-tuning. Additionally, it identifies two previously unexplored synergistic drug combinations for distinct cancer types in disease-specific biological network environments. These findings are further validated through in vitro cytotoxicity assays, demonstrating the potential of the model to enhance drug development and identify effective treatment regimens for specific diseases.

Dual-driven biodegradable nanomotors for enhanced cellular uptake.

Hybrid nano-sized motors with navigation and self-actuation capabilities have emerged as promising nanocarriers for a wide range of delivery, sensing, and diagnostic applications due to their unique ability to achieve controllable locomotion within a complex biological environment such as tissue. However, most current nanomotors typically operate using a single driving mode, whereas propulsion induced by both external and local stimuli could be more beneficial to achieve efficient motility in a biomedical setting. In this work, we present a hybrid nanomotor by functionalizing biodegradable stomatocytes with platinum nanoparticles (Pt NPs). These Pt NPs enable two distinct propulsion mechanisms. First, near-infrared (NIR) laser irradiation causes plasmonic heating, which, due to the asymmetric shape of the stomatocytes, creates a temperature gradient around the nanomotors. Second, the catalytic properties of the Pt NPs allow them to convert hydrogen peroxide into water and oxygen, generating a chemical gradient that serves as an additional driving force. Hydrogen peroxide is thereby locally produced from endogenous glucose by a co-encapsulated enzyme, glucose oxidase. The motile features are employed to achieve enhanced accumulation within tumor cells. This nanomotor design offers a versatile approach for developing dual stimuli-responsive nanomotors that operate more effectively in complex environments.

Five‐Modal Three‐Dimensional Optical Microscopy via Single 1550 nm Fiber Laser

Multimodal optical microscopy can be used to visualize multiple biological targets at the same location and at similar spatial resolutions, enabling more comprehensive studies of complex biological samples. However, current multimodal imaging systems typically use multiple or specially designed excitation lasers. Furthermore, previous studies have reported only three or four types of imaging modalities, limiting the number of imaging targets. This study develops an imaging system based on a single commercialized 1550 nm fiber laser and integrates five imaging modalities: second harmonic generation, third harmonic generation, two‐photon fluorescence, three‐photon fluorescence, and reflected confocal microscopy. Utilizing the characteristics of different imaging modalities, various biological components in biological tissues can be revealed simultaneously and cell movement in a complex biological environment can be traced noninvasively. The capacity of deep imaging has also been demonstrated in the mouse brain. The results show that the proposed multimodal microscopy system has great application potential in biomedical fields, such as tumor diagnosis and immunotherapy.

Silica Nanoparticle-Protein Aggregation and Protein Corona Formation Investigated with Scattering Techniques.

Protein-nanoparticle interactions and the resulting corona formation play crucial roles in the behavior and functionality of nanoparticles in biological environments. In this study, we present a comprehensive analysis of protein corona formation with superfolder green fluorescent protein (sfGFP) and bovine serum albumin in silica nanoparticle dispersions using small-angle X-ray scattering (SAXS) and dynamic light scattering (DLS). For the first time, we subtracted the scattering of individual proteins in solution and individual nanoparticles from the protein-nanoparticle complexes. This approach effectively isolated the contributions of specific components within the corona. Our form factor analysis revealed consistent core-shell sphere thicknesses but varied attractive interaction strengths of the nanoparticle complexes, influenced by the protein corona and the surface properties of silica and aminated silica nanoparticles. Interestingly, fractal analysis of nanoparticles showed a transition from surface to mass fractals for sfGFP samples at high protein:nanoparticle molar ratios of over 264,000:1. DLS analysis highlighted aggregation behaviors, including the increasing size of protein-nanoparticle complexes and significant aggregation of both free proteins and complexes at ∼264,000 molar ratio. Large polydispersity and heterogeneous protein aggregation were observed at these high molar ratios. Both SAXS and DLS revealed transitions and changes in protein-nanoparticle interactions at molar ratios of 4000 to 44,000, consistent with corona formation, while pronounced aggregation was observed at a molar ratio of ∼264,000. These findings advance our understanding of the structural complexities in protein-nanoparticle association and suggest further avenues for refining characterization techniques in protein corona research.