Self-Enhanced Acoustic Impedance Difference Strategy for Detecting the Acidic Tumor Microenvironment

Pioneering Insights into the Reaction Kinetics of Metastable Intermolecular Composites Based on Metal Fluorides: Virtually non-existent condensed Phase Combustion Products and Ultra-Efficient Reactivity

As a typical representative of Metastable intermolecular composites (MICs), the energy release of nano-thermites relying on aluminum-oxygen reaction is limited by the formation of high boiling point condensed phase products. Low pressure output performance constitutes another pivotal factor influencing their efficacy. In this work, metal fluorides BiF3 at different scales were incorporated into nano-thermites as oxidants, thereby facilitating the tunability of the released energy. The boiling points of all resultant reaction products fall below the combustion temperature, theoretically abolishing the agglomeration of condensed-phase products, thus preventing the entrapment of active metals. Additionally, it facilitates the smooth conduction of heat flux, thereby averting losses in biphasic flow dynamics. The n-Al/n-BiF3 system exhibits a significant amplification in reactive kinetic properties in stark contrast to the n-Al/n-Bi2O3 system. The reduction in ignition threshold is ascribed to a novel reaction kinetics mechanism within the n-Al/BiF3 system. The highly electronegative fluorine within BiF3 corrodes the Al2O3 shell, inducing a "pre-ignition" reaction. The application of Density Functional Theory (DFT) evaluations has further corroborated the n-Al/n-BiF3 system's preeminence in electron transfer capacity between the oxidizing agent and fuel, thereby furnishing an molecular-electronic basis for its potent reactive kinetic properties.

Bismuth drug-inspired ultra-small dextran coated bismuth oxide nanoparticles for targeted computed tomography imaging of inflammatory bowel disease

Bismuth (Bi)-based computed tomography (CT) imaging contrast agents (CAs) hold significant promise for diagnosing gastrointestinal diseases due to their cost-effectiveness, heightened sensitivity, and commendable biocompatibility. Nevertheless, substantial challenges persist in achieving an easy synthesis process, remarkable water solubility, and effective targeting ability for the potential clinical transformation of Bi-based CAs. Herein, we show Bi drug-inspired ultra-small dextran coated bismuth oxide nanoparticles (Bi2O3-Dex NPs) for targeted CT imaging of inflammatory bowel disease (IBD). Bi2O3-Dex NPs are synthesized through a simple alkaline precipitation reaction using bismuth salts and dextran as the template. The Bi2O3-Dex NPs exhibit ultra-small size (3.4 nm), exceptional water solubility (over 200 mg mL-1), high Bi content (19.75 %), excellent biocompatibility and demonstrate higher X-ray attenuation capacity compared to clinical iohexol. Bi2O3-Dex NPs not only enable clear visualization of the GI tract outline and intestinal loop structures in CT imaging but also specifically target and accumulate at the inflammatory site in colitis mice after oral administration, facilitating a precise diagnosis and enabling targeted CT imaging of IBD. Our study introduces a novel and clinically promising strategy for synthesizing high-performance Bi2O3-Dex NPs for diagnosing gastrointestinal diseases.

Non-Invasive Monitoring of Cerebral Edema Using Ultrasonic Echo Signal Features and Machine Learning

OBJECTIVES

Cerebral edema, a prevalent consequence of brain injury, is associated with significant mortality and disability. Timely diagnosis and monitoring are crucial for patient prognosis. There is a pressing clinical demand for a real-time, non-invasive cerebral edema monitoring method. Ultrasound methods are prime candidates for such investigations due to their non-invasive nature.

METHODS

Acute cerebral edema was introduced in rats by permanently occluding the left middle cerebral artery (MCA). Ultrasonic echo signals were collected at nine time points over a 24 h period to extract features from both the time and frequency domains. Concurrently, histomorphological changes were examined. We utilized support vector machine (SVM), logistic regression (LogR), decision tree (DT), and random forest (RF) algorithms for classifying cerebral edema types, and SVM, RF, linear regression (LR), and feedforward neural network (FNNs) for predicting the cerebral infarction volume ratio.

RESULTS

The integration of 16 ultrasonic features associated with cerebral edema development with the RF model enabled effective classification of cerebral edema types, with a high accuracy rate of 97.9%. Additionally, it provided an accurate prediction of the cerebral infarction volume ratio, with an R2 value of 0.8814.

CONCLUSIONS

Our proposed strategy classifies cerebral edema and predicts the cerebral infarction volume ratio with satisfactory precision. The fusion of ultrasound echo features with machine learning presents a promising non-invasive approach for the monitoring of cerebral edema.

A dual-capture-system polymer based on imprinted cavities and post-imprinting modification sites with significantly improved affinity and specificity for sialic acid and sialylated glycoprotein

The abnormal expression of N-acetylneuraminic acid (SA) and sialylated glycoproteins in biological fluids are closely associated with various diseases including cancer. However, the low content of SA and the strong interference of complex matrix greatly influence the effective capture of SA in biosamples prior to analysis. Herein, a dual-capture-system strategy based on molecular imprinting and post-imprinting modification (PIM) was proposed to precisely capture SA with improved binding affinity and specificity. After imprinting with SA as template, dynamic imine bonds are introduced by post-imprinting modification, enabling sufficiently high specificity to capture SA through imprinting cavities and the dynamic imine bonds hydrolysis reaction simultaneously. The prepared magnetic PIM polymers (Mag-MIPs-PIM) exhibited significantly high specificity both for SA (IF = 4.24) and sialylated glycoprotein (IFTRF = 3.50). In addition, the feasibility of Mag-MIPs-PIM for practical application was demonstrated by association with HPLC for the determination of SA in human serum, and an LOD of 0.01 × 10-2 g L-1 was obtained. The proposed strategy based on molecular imprinting and PIM provides a new inspiration for the improvement of selectivity of the molecularly imprinted polymers.

The advance of ultrasound-enabled diagnostics and therapeutics

Point-of-care ultrasound demonstrates significant potential in biomedical research due to its noninvasive, real-time visualization, cost-effectiveness, and other biological benefits. Ultrasound irradiation can precisely control the mechanical and physicochemical effects on pathogenic lesions, enabling real-time visualization, tunable tissue penetration depth, and therapeutic applications. This review summarizes recent advancements in ultrasound-enabled diagnostics and therapeutics, focusing on mechanochemical effects that can be directly integrated into biomedical applications. Additionally, the structure-functionality relationships of sonotheranostic nanoplatforms are systematically discussed, providing insights into the underlying biological effects. Finally, the limitations of current ultrasonic medicine are discussed, along with potential expansions to facilitate patient-centered translations.

β-Cyclodextrin-based nanoassemblies for the treatment of atherosclerosis

Atherosclerosis, a chronic and progressive condition characterized by the accumulation of inflammatory cells and lipids within artery walls, remains a leading cause of cardiovascular diseases globally. Despite considerable advancements in drug therapeutic strategies aimed at managing atherosclerosis, more effective treatment options for atherosclerosis are still warranted. In this pursuit, the emergence of β-cyclodextrin (β-CD) as a promising therapeutic agent offers a novel therapeutic approach to drug delivery targeting atherosclerosis. The hydrophobic cavity of β-CD facilitates its role as a carrier, enabling the encapsulation and delivery of various therapeutic compounds to affected sites within the vasculature. Notably, β-CD-based nanoassemblies possess the ability to reduce cholesterol levels, mitigate inflammation, solubilize hydrophobic drugs and deliver drugs to affected tissues, making these nanocomponents promising candidates for atherosclerosis management. This review focuses on three major classes of β-CD-based nanoassemblies, including β-CD derivatives-based, β-CD/polymer conjugates-based and polymer β-CD-based nanoassemblies, highlighting a variety of formulations and assembly methods to improve drug delivery and therapeutic efficacy. These β-CD-based nanoassemblies exhibit a variety of therapeutic mechanisms for atherosclerosis and offer systematic strategies for overcoming barriers to drug delivery. Finally, we discuss the present obstacles and potential opportunities in the development and application of β-CD-based nanoassemblies as novel therapeutics for managing atherosclerosis and addressing cardiovascular diseases.

Layered Double Hydroxides: Recent Progress and Promising Perspectives Toward Biomedical Applications

Layered double hydroxides (LDHs) have been widely studied for biomedical applications due to their excellent properties, such as good biocompatibility, degradability, interlayer ion exchangeability, high loading capacity, pH-responsive release, and large specific surface area. Furthermore, the flexibility in the structural composition and ease of surface modification of LDHs makes it possible to develop specifically functionalized LDHs to meet the needs of different applications. In this review, the recent advances of LDHs for biomedical applications, which include LDH-based drug delivery systems, LDHs for cancer diagnosis and therapy, tissue engineering, coatings, functional membranes, and biosensors, are comprehensively discussed. From these various biomedical research fields, it can be seen that there is great potential and possibility for the use of LDHs in biomedical applications. However, at the same time, it must be recognized that the actual clinical translation of LDHs is still very limited. Therefore, the current limitations of related research on LDHs are discussed by combining limited examples of actual clinical translation with requirements for clinical translation of biomaterials. Finally, an outlook on future research related to LDHs is provided.

Metallic artifacts-free spectral computed tomography angiography based on renal clearable bismuth chelate

Computed tomography angiography (CTA) is one of the most important diagnosis techniques for various vascular diseases in clinic. However, metallic artifacts caused by metal implants and calcified plaques in more and more patients severely hinder its wide applications. Herein, we propose an improved metallic artifacts-free spectral CTA technique based on renal clearable bismuth chelate (Bi-DTPA dimeglumine) for the first time. Bi-DTPA dimeglumine owns the merits of ultra-simple synthetic process, approximately 100% of yield, large-scale production capability, good biocompatibility, and favorable renal clearable ability. More importantly, Bi-DTPA dimeglumine shows superior contrast-enhanced effect in CTA compared with clinical iohexol at a wide range of X-ray energies especially in higher X-ray energy. In rabbits' model with metallic transplants, Bi-DTPA dimeglumine assisted-spectral CTA can not only effectively mitigate metallic artifacts by reducing beam hardening effect under high X-ray energy, but also enables accurate delineation of vascular structure. Our proposed strategy opens a revolutionary way to solve the bottleneck problem of metallic artifacts in CTA examinations.

Morphologically transformable peptide nanocarriers coloaded with doxorubicin and curcumin inhibit the growth and metastasis of hepatocellular carcinoma

In tumor treatment, the highly disordered vascular system and lack of accumulation of chemotherapeutic drugs in tumors severely limit the therapeutic role of nanocarriers. Smaller drug-containing nanoparticles (NPs) can better penetrate the tumor but are easily removed, which severely limits the tumor-killing properties of the drug. The chemotherapeutic medication doxorubicin (DOX) is highly toxic to the heart, but this toxicity can be effectively mitigated and the combined anticancer effect can be enhanced by clinically incorporating curcumin (CUR) as part of the dual therapy. We designed a small-molecule peptide, Pep1, containing a targeting peptide (CREKA) and a pH-responsive moiety. These NPs can target the blood vessels in tumor microthrombi and undergo a morphological shift in the tumor microenvironment. This process enhances the penetration and accumulation of drugs, ultimately improving the effectiveness of cancer treatment. In vitro and in vivo experiments demonstrated that this morphological transformation allowed rapid and effective drug release into tumors, the effective inhibition of tumor angiogenesis, and the promotion of tumor cell apoptosis, thus effectively killing tumor cells. Our findings provide a novel and simple approach to nhibit the growth and metastasis of hepatocellular carcinoma.

Bioactive inorganic nanomaterials for cancer theranostics

Bioactive materials are a special class of biomaterials that can react in vivo to induce a biological response or regulate biological functions, thus achieving a better curative effect than traditional inert biomaterials. For cancer theranostics, compared with organic or polymer nanomaterials, inorganic nanomaterials possess unique physical and chemical properties, have stronger mechanical stability on the basis of maintaining certain bioactivity, and are easy to be compounded with various carriers (polymer carriers, biological carriers, etc.), so as to achieve specific antitumor efficacy. After entering the nanoscale, due to the nano-size effect, high specific surface area and special nanostructures, inorganic nanomaterials exhibit unique biological effects, which significantly influence the interaction with biological organisms. Therefore, the research and applications of bioactive inorganic nanomaterials in cancer theranostics have attracted wide attention. In this review, we mainly summarize the recent progress of bioactive inorganic nanomaterials in cancer theranostics, and also introduce the definition, synthesis and modification strategies of bioactive inorganic nanomaterials. Thereafter, the applications of bioactive inorganic nanomaterials in tumor imaging and antitumor therapy, including tumor microenvironment (TME) regulation, catalytic therapy, gas therapy, regulatory cell death and immunotherapy, are discussed. Finally, the biosafety and challenges of bioactive inorganic nanomaterials are also mentioned, and their future development opportunities are prospected. This review highlights the bioapplication of bioactive inorganic nanomaterials.

Two birds one stone: β-fluoropyrrolyl-cysteine SNAr chemistry enabling functional porphyrin bioconjugation

Bioconjugation, a synthetic tool that endows small molecules with biocompatibility and target specificity through covalent attachment of a biomolecule, holds promise for next-generation diagnosis or therapy. Besides the establishment of chemical bonding, such chemical modification concurrently allows alteration of the physicochemical properties of small molecules, but this has been paid less attention in designing novel bioconjugates. Here, we report a "two birds one stone" methodology for irreversible porphyrin bioconjugation based on β-fluoropyrrolyl-cysteine S_NAr chemistry, in which the β-fluorine of porphyrin is selectively replaced by a cysteine in either peptides or proteins to generate novel β-peptidyl/proteic porphyrins. Notably, due to the distinct electronic nature between fluorine and sulfur, such replacement makes the Q band red-shift to the near-infrared region (NIR, >700 nm). This facilitates intersystem crossing (ISC) to enhance the triplet population and thus singlet oxygen production. This new methodology features water tolerance, a fast reaction time (15 min), good chemo-selectivity, and broad substrate scope, including various peptides and proteins under mild conditions. To demonstrate its potential, we applied porphyrin β-bioconjugates in several scenarios, including (1) cytosolic delivery of functional proteins, (2) metabolic glycan labeling, (3) caspase-3 detection, and (4) tumor-targeting phototheranostics.

Integration of Silica Nanorattles with Manganese-Doped In2S3/InOOH to Enable Ultrasound-Mediated Tumor Theranostics

As a result of their radiation-free nature and deep-penetration ability, tumor theranostics mediated by ultrasound have become increasingly recognized as a modality with high potential for translation into clinical cancer treatment. The effective integration of ultrasound imaging and sonodynamic therapy (SDT) into one nanoplatform remains an enormous challenge yet to be fully resolved. Here, a novel theranostic system, consisting of rattle-type SiO₂ (r-SiO₂) loaded with Mn-doped In₂S₃/InOOH (SMISO), was designed and synthesized to enable an improved ultrasound imaging-guided therapy. With Mn-doped In₂S₃/InOOH (MISO) and a heterojunction structure, this novel sonosensitizer facilitates the generation of reactive oxygen species (ROS) for SDT. By coupling interfaces between the shell and core in rattle-type SiO₂, multiple reflections/scattering are generated, while MISO has high acoustic impedance. By integrating r-SiO₂ and MISO, the SMISO composite nanoparticles (NPs) increase the acoustic reflection and provide enhanced contrast for ultrasound imaging. Through the effective accumulation in tumors, which was monitored by B-mode ultrasound imaging in vivo, SMISO composite NPs effectively inhibited tumor growth without adverse side effects under ultrasound irradiation treatment. This work therefore provides a new approach to integrate a novel gas-free ultrasound contrast agent and a semiconductor sonosensitizer for cancer theranostics.