Recent Trend of Ultrasound-Mediated Nanoparticle Delivery for Brain Imaging and Treatment

The reprotoxic adverse side effects of neurogenic and neuroprotective drugs: current use of human organoid modeling as a potential alternative to preclinical models

The management of neurological disorders heavily relies on neurotherapeutic drugs, but notable concerns exist regarding their possible negative effects on reproductive health. Traditional preclinical models often fail to accurately predict reprotoxicity, highlighting the need for more physiologically relevant systems. Organoid models represent a promising approach for concurrently studying neurotoxicity and reprotoxicity, providing insights into the complex interplay between neurotherapeutic drugs and reproductive systems. Herein, we have examined the molecular mechanisms underlying neurotherapeutic drug-induced reprotoxicity and discussed experimental findings from case studies. Additionally, we explore the utility of organoid models in elucidating the reproductive complications of neurodrug exposure. Have discussed the principles of organoid models, highlighting their ability to recapitulate neurodevelopmental processes and simulate drug-induced toxicity in a controlled environment. Challenges and future perspectives in the field have been addressed with a focus on advancing organoid technologies to improve reprotoxicity assessment and enhance drug safety screening. This review underscores the importance of organoid models in unraveling the complex relationship between neurotherapeutic drugs and reproductive health.

Blood-Brain Barrier-Targeting Nanoparticles: Biomaterial Properties and Biomedical Applications in Translational Neuroscience

Overcoming the blood-brain barrier (BBB) remains a significant hurdle in effective drug delivery to the brain. While the BBB serves as a crucial protective barrier, it poses challenges in delivering therapeutic agents to their intended targets within the brain parenchyma. To enhance drug delivery for the treatment of neurological diseases, several delivery technologies to circumvent the BBB have been developed in the last few years. Among them, nanoparticles (NPs) are one of the most versatile and promising tools. Here, we summarize the characteristics of NPs that facilitate BBB penetration, including their size, shape, chemical composition, surface charge, and importantly, their conjugation with various biological or synthetic molecules such as glucose, transferrin, insulin, polyethylene glycol, peptides, and aptamers. Additionally, we discuss the coating of NPs with surfactants. A comprehensive overview of the common in vitro and in vivo models of the BBB for NP penetration studies is also provided. The discussion extends to discussing BBB impairment under pathological conditions and leveraging BBB alterations under pathological conditions to enhance drug delivery. Emphasizing the need for future studies to uncover the inherent therapeutic properties of NPs, the review advocates for their role beyond delivery systems and calls for efforts translating NPs to the clinic as therapeutics. Overall, NPs stand out as a highly promising therapeutic strategy for precise BBB targeting and drug delivery in neurological disorders.

Second Near-Infrared Macrophage-Biomimetic Nanoprobes for Photoacoustic Imaging of Neuroinflammation

Neuroinflammation is a significant pathological event involving the neurodegenerative process associated with many neurological disorders. Diagnosis and treatment of neuroinflammation in its early stage are essential for the prevention and management of neurological diseases. Herein, we designed macrophage membrane-coated photoacoustic (PA) probes (MSINPs), with targeting specificities based on naturally existing target-ligand interactions for the early diagnosis of neuroinflammation. The second near-infrared dye, IR1061, was doped into silica as the core and was encapsulated with a macrophage membrane. In vitro as well as in vivo, the MSINPs could target inflammatory cells via the inflammation chemotactic effect. PA imaging was used to trace the MSINPs in a neuroinflammation mouse model and showed a great targeted effect of MSINPs in the prefrontal cortex. Therefore, the biomimetic nanoprobe prepared in this study offers a new strategy for PA molecular imaging of neuroinflammation, which can enhance our understanding of the evolution of neuroinflammation in specific brain regions.

Recent advances in nanomaterials for neural applications: opportunities and challenges

Nanomedicines are promising for delivering drugs to the central nervous system, though their precision is still being improved. Fortifying nanoparticles with vital molecules can interact with the blood-brain barrier, enabling access to brain tissue. This study summarizes recent advances in nanomedicine to treat neurological complications. The integration of nanotechnology into cell biology aids in the study of brain cells' interactions. Magnetic microhydrogels have exhibited superior neuron activation compared with superparamagnetic iron oxide nanoparticles and hold promise for neuropsychiatric disorders. Nanomaterials have shown notable results, such as tackling neurodegenerative diseases by hindering harmful protein buildup and regulating cellular processes. However, further studies of the safety and effectiveness of nanoparticles in managing neurological diseases and disorders are still required.

The innovative design of a delivery and real-time tracer system for anti-encephalitis drugs that can penetrate the blood-brain barrier

As a "wall" between blood flow and brain cells, the blood-brain barrier (BBB) makes it really difficult for drugs to cross this barrier and work. This is particularly the case for pharmaceuticals of acute encephalitis therapies, largely excluded from the brain following systemic administration. Herein we report an advanced drug delivery system that can cross the BBB and target acute inflammation based on the controlled release of macrophage-camouflaged glow nanoparticles via a Trojan horse strategy. Benefiting from afterglow imaging that eliminates background interference and RAW 264.7 cells (RAW) with special immune homing and long-term tracking capabilities, polydopamine (PDA)-modified afterglow nanoparticles (ANPs) as near-infrared photo-responsive drug carriers in a controlled delivery system camouflaged by macrophages can penetrate the BBB by crossing the intercellular space and trigger the anti-inflammatory drug by photothermal conversion in the brain parenchyma dexamethasone (Dex) release, exhibiting good acute inflammation recognition and healing ability. APD@RAW was monitored to cross the BBB and image deep brain inflamed areas in a model of acute brain inflammation. Meanwhile, the delivered Dex mitigated the brain damage caused by inflammatory cytokines secretion (IL-6, TNF-α, and IL-1β). Overall, this drug delivery system holds excellent potential for BBB penetrating and acute encephalitis therapies.

Magnetic Targeting Nanocarriers Combined with Focusing Ultrasound for Enhanced Intracerebral Hemorrhage Therapy

Intracerebral hemorrhage (ICH) remains a significant cause of morbidity and mortality around the world, and surgery is still the most direct and effective way to remove ICH. However, the potential risks brought by surgery, such as normal brain tissue damage, post-operative infection, and difficulty in removing deep hematoma, are still the main problems in the surgical treatment of ICH. Activation of the peroxisome proliferator-activated receptor gamma (PPARγ) is reported to show a good therapeutic effect in hematoma clearance. Herein, a magnetic targeting nanocarrier loaded with a PPARγ agonist (15d-PGJ2-MNPs) is synthesized, which could be magnetically targeted and enriched in the area of the hematoma after intravenous injection. Subsequent application of focusing ultrasound (FUS) could enhance drug diffusion, which activates the PPARγ receptors on macrophages around the hematoma for better hematoma clearance. The 15d-PGJ2-MNP treatment alleviates brain injury, accelerates hematoma clearance, attenuates neuroinflammation, reduces brain edema and significantly improves the deficits in sensory and motor function and spatial learning ability in the ICH mouse model. This work proposes an effective magnetic targeting plus FUS method to treat ICH, highlighting its great potential in the treatment of hemorrhagic stroke.

Ultrasound-mediated nano drug delivery for treating cancer: Fundamental physics to future directions

The application of biocompatible nanocarriers in medicine has provided several benefits over conventional treatment methods. However, achieving high treatment efficacy and deep penetration of nanocarriers in tumor tissue is still challenging. To address this, stimuli-responsive nano-sized drug delivery systems (DDSs) are an active area of investigation in delivering anticancer drugs. While ultrasound is mainly used for diagnostic purposes, it can also be applied to affect cellular function and the delivery/release of anticancer drugs. Therapeutic ultrasound (TUS) has shown potential as both a stand-alone anticancer treatment and a method to induce targeted drug release from nanocarrier systems. TUS approaches have been used to overcome various physiological obstacles, including endothelial barriers, the tumor microenvironment (TME), and immunological hurdles. Combining nanomedicine and ultrasound as a smart DDS can increase in situ drug delivery and improve access to impermeable tissues. Furthermore, smart DDSs can perform targeted drug release in response to distinctive TMEs, external triggers, or dual/multi-stimulus. This results in enhanced treatment efficacy and reduced damage to surrounding healthy tissue or organs at risk. Integrating DDSs and ultrasound is still in its early stages. More research and clinical trials are required to fully understand ultrasound's underlying physical mechanisms and interactions with various types of nanocarriers and different types of cells and tissues. In the present review, ultrasound-mediated nano-sized DDS, specifically focused on cancer treatment, is presented and discussed. Ultrasound interaction with nanoparticles (NPs), drug release mechanisms, and various types of ultrasound-sensitive NPs are examined. Additionally, in vitro, in vivo, and clinical applications of TUS are reviewed in light of the critical challenges that need to be considered to advance TUS toward an efficient, secure, straightforward, and accessible cancer treatment. This study also presents effective TUS parameters and safety considerations for this treatment modality and gives recommendations about system design and operation. Finally, future perspectives are considered, and different TUS approaches are examined and discussed in detail. This review investigates drug release and delivery through ultrasound-mediated nano-sized cancer treatment, both pre-clinically and clinically.

Controllable blood–brain barrier (BBB) regulation based on gigahertz acoustic streaming

The blood–brain barrier (BBB) is a structural and functional barrier necessary for brain homeostasis, and it plays an important role in the realization of neural function and in protecting the brain from damage by circulating toxins and pathogens. However, the extremely dense BBB also severely limits the transport of molecules across it, which is a great hindrance to the diagnosis and treatment of central nervous system (CNS) diseases. This paper reports a new method for controllable opening of the BBB, based on the gigahertz acoustic streaming (AS) generated by a bulk acoustic wave resonant device. By adjusting the input power and working distance of the device, AS with tunable flow rate can be generated to disrupt tight junction proteins (TJs) between endothelial cells. The results obtained with this method show that the gigahertz AS promotes the penetration of dextran molecules with different molecular weights across the BBB. This work provides a new platform for studying the mechanical regulation of BBB by fluid shear forces and a new method for improving the efficiency of drug delivery.