Emerging nanobiotechnology-encoded relaxation tuning establishes new MRI modes to localize, monitor and predict diseases

A branched polymer-based agent for efficient and precise targeting of fibrosis diseases by magnetic resonance imaging

Herein, we synthesized and characterized gadolinium-based hyperbranched polymers, POADGd and PODGd, through RAFT polymerization as magnetic resonance imaging (MRI) contrast agents for detecting fibrosis. POADGd and PODGd contain biocompatible short-chain OEGMA to prolong blood circulation, and they can be decomposed in response to ROS after MRI examination to prevent potential accumulation. The relaxivities of POADGd and PODGd are 9.81 mM-1 s-1 and 9.58 mM-1 s-1 respectively, which are significantly higher than that of DTPA-Gd, a clinically used agent (3.74 mM-1 s-1). In comparison with PODGd, POADGd can specifically target allysine in fibrosis tissues through its oxyamine groups. Therefore, it displays a sharp spatial resolution and a high signal-to-noise ratio in the liver and lung fibrosis tissue at a field strength of 3.0 T or 7.0 T, and the morphology of these fibrosis tissues is accurately delineated. Our MRI diagnosis results based on POADGd are highly aligned with those from pathological examinations, while MRI diagnosis could avoid invasive biopsy. In addition, POADGd shows excellent biosafety and low toxicity. Therefore, POADGd could be applied to non-invasively and accurately diagnose liver and lung fibrosis diseases.

Physiochemically and Genetically Engineered Bacteria: Instructive Design Principles and Diverse Applications

With the comprehensive understanding of microorganisms and the rapid advances of physiochemical engineering and bioengineering technologies, scientists are advancing rationally-engineered bacteria as emerging drugs for treating various diseases in clinical disease management. Engineered bacteria specifically refer to advanced physiochemical or genetic technologies in combination with cutting edge nanotechnology or physical technologies, which have been validated to play significant roles in lysing tumors, regulating immunity, influencing the metabolic pathways, etc. However, there has no specific reviews that concurrently cover physiochemically- and genetically-engineered bacteria and their derivatives yet, let alone their distinctive design principles and various functions and applications. Herein, the applications of physiochemically and genetically-engineered bacteria, and classify and discuss significant breakthroughs with an emphasis on their specific design principles and engineering methods objective to different specific uses and diseases beyond cancer is described. The combined strategies for developing in vivo biotherapeutic agents based on these physiochemically- and genetically-engineered bacteria or bacterial derivatives, and elucidated how they repress cancer and other diseases is also underlined. Additionally, the challenges faced by clinical translation and the future development directions are discussed. This review is expected to provide an overall impression on physiochemically- and genetically-engineered bacteria and enlighten more researchers.

A non-invasive osteopontin-targeted phase changeable fluorescent nanoprobe for molecular imaging of myocardial fibrosis

Due to the elevated fatality rate of cardiovascular diseases, myocardial fibrosis emerges as a prominent pathological alteration in the majority of heart ailments and their associated pathologies, thereby augmenting the likelihood of sudden cardiac death. Consequently, the prompt and obligatory identification of myocardial fibrosis assumes paramount importance in averting malignant incidents among patients afflicted with cardiac disorders. Herein, with higher expression osteopontin (OPN) found in cardiac fibrosis tissue, we have developed a dual-modality imaging probe, namely OPN targeted nanoparticles (OPN@PFP-DiR NPs), which loaded perfluoropentane (PFP) for ultrasound (US) and 1,1-dioctadecyl-3,3,3,3-tetramethylindotricarbocyanine iodide (DiR) for near-infrared fluorescence (NIR) of molecular imaging, to investigate the molecular features of cardiac fibrosis using US and NIR imaging. Subsequently, the OPN@PFP-DiR NPs were administered intravenously to a mouse model of myocardial infarction (MI). The US and NIR molecular imaging techniques were employed to visualize the accumulation of the nanoparticles in the fibrotic myocardium. Hence, this research presents a valuable noninvasive, cost-effective, and real-time imaging method for evaluating cardiac fibrosis, with promising clinical applications.

Epilepsy Treatment and Diagnosis Enhanced by Current Nanomaterial Innovations: A Comprehensive Review

Epilepsy is a complex disease in the brain. Complete control of seizure has always been a challenge in epilepsy treatment. Currently, clinical management primarily involves pharmacological and surgical interventions, with the former being the preferred approach. However, antiepileptic drugs often exhibit low bioavailability due to inherent limitations such as poor water solubility and difficulty penetrating the blood-brain barrier (BBB). These issues significantly reduce the drugs' effectiveness and limit their clinical application in epilepsy treatment. Additionally, the diagnostic accuracy of current imaging techniques and electroencephalography (EEG) for epilepsy is suboptimal, often failing to precisely localize epileptogenic tissues. Accurate diagnosis is critical for the surgical management of epilepsy. Thus, there is a pressing need to enhance both the therapeutic outcomes of epilepsy medications and the diagnostic precision of the condition. In recent years, the advancement of nanotechnology in the biomedical sector has led to the development of nanomaterials as drug carriers. These materials are designed to improve drug bioavailability and targeting by leveraging their large specific surface area, facile surface modification, ability to cross the BBB, and high biocompatibility. Furthermore, nanomaterials have been utilized as contrast agents in imaging and as materials for EEG electrodes, enhancing the accuracy of epilepsy diagnoses. This review provides a comprehensive examination of current research on nanomaterials in the treatment and diagnosis of epilepsy, offering new strategies and directions for future investigation.

Achieving Complete Tumor Clearance: A Minimalist Manganese Hydrogel for Magnetic Resonance Imaging-Guided Synergetic Microwave Ablation and Chemodynamic Therapy

The combination of microwave ablation (MWA) and chemodynamic therapy (CDT) presents a promising strategy for complete eradication of residual tumor after MWA. However, it remains challenging and urgent to develop a facile, biocompatible, and imaging-guided platform for the achievement of this goal. Herein, a minimalist manganese hydrogel (ALG-Mn hydrogel) is proposed for synergistic MWA and CDT to completely eradicate tumor in vivo. The ALG-Mn hydrogel is prepared using a simple mixing method and exhibits excellent syringeability, remarkable microwave sensitivity, and potent Fenton-like activity. By assisting in MWA procedures, the ALG-Mn hydrogel enables both elimination of primary tumor mass through enhanced MWA efficacy and eradication of potential residual tumor tissues via robust CDT. This approach achieves complete tumor clearance without additional drug loading. Furthermore, the paramagnetic Mn2+ component allows real-time dynamic visualization of the ALG-Mn hydrogel at the tumor site via magnetic resonance imaging. To the best of knowledge, the proposed ALG-Mn hydrogel represents the minimalist biocompatible platform for imaging-guided synergistic MWA and CDT toward achieving complete tumor clearance.

Toward Ultrasound Molecular Imaging of Endothelial Dysfunction in Diabetes: Targets, Strategies, and Challenges

Diabetes vasculopathy is a significant complication of diabetes mellitus (DM), and early identification and timely intervention can effectively slow the progression. Accumulating studies have shown that diabetes causes vascular complications directly or indirectly through a variety of mechanisms. Direct imaging of the endothelial molecular changes not only identifies the early stage of diabetes vasculopathy but also sheds light on the precise treatment. Targeted ultrasound contrast agent (UCA)-based ultrasound molecular imaging (UMI) can noninvasively detect the expression status of molecular biomarkers overexpressed in the vasculature, thereby being a potential strategy for the diagnosis and treatment response evaluation of DM. Amounts of efforts have been focused on identification of the molecular targets expressed in the vasculature, manufacturing strategies of the targeted UCA, and the clinical translation for the diagnosis and evaluation of therapeutic efficacy in both micro- and macrovasculopathy in DM. This review summarizes the latest research progress on endothelium-targeted UCA and discusses their promising future and challenges in diabetes vasculopathy theranostics.

A dual-targeted Gd-based contrast agent for magnetic resonance imaging in tumor diagnosis

Enhanced magnetic resonance imaging (MRI) has important clinical value in the diagnosis of tumors. Much effort has been made to improve the relaxivity and specificity of contrast agents (CAs) in tumor diagnosis over the past few decades. However, there is still a lack of CAs which not only enhance the signal intensity of tumors rather than surrounding tissues in MRI but also maintain a high signal intensity prolonged for a long time. Herein, we synthesized a dual-targeted CA, RGD-(DOTA-Gd)-TPP (RDP), in which RGD is used to target the αvβ3 integrin receptor overexpressed in tumor cells and TPP is used to bind to a mitochondrion further. The structure of RDP was characterized and its properties, such as relaxivity and biosafety, were measured and in vitro and in vivo MRI assays were carried out. It has been proven that RDP has higher relaxivity of aqueous solution than Magnevist used in clinics. Moreover, RDP achieved higher signal intensity and a longer signal duration in tumor imaging. Therefore, RDP can be applied as the potential dual-targeted MRI CA for clinical tumor diagnosis.

Advances in nanobiotechnology-propelled multidrug resistance circumvention of cancer

Multidrug resistance (MDR) is one of the main reasons for the failure of tumor chemotherapy and has a negative influence on the therapeutic effect. MDR is primarily attributable to two mechanisms: the activation of efflux pumps for drugs, which can transport intracellular drug molecules from cells, and other mechanisms not related to efflux pumps, e.g., apoptosis prevention, strengthened DNA repair, and strong oxidation resistance. Nanodrug-delivery systems have recently attracted much attention, showing some unparalleled advantages such as drug targeting and reduced drug efflux, drug toxicity and side effects in reversing MDR. Notably, in drug-delivery platforms based on nanotechnology, multiple therapeutic strategies are integrated into one system, which can compensate for the limitations of individual strategies. In this review, the mechanisms of tumor MDR as well as common vectors and nanocarrier-combined therapy strategies to reverse MDR were summarized to promote the understanding of the latest progress in improving the efficiency of chemotherapy and synergistic strategies. In particular, the adoption of nanotechnology has been highlighted and the principles underlying this phenomenon have been elucidated, which may provide guidance for the development of more effective anticancer strategies.