The effect of nanoparticle size on the ability to cross the blood-brain barrier: an in vivo study

Beyond surface modification strategies to control infections associated with implanted biomaterials and devices - Addressing the opportunities offered by nanotechnology

Biomaterial-associated infection (BAI) is considered a unique infection due to the presence of a biomaterial yielding frustrated immune-cells, ineffective in clearing local micro-organisms. The involvement of surface-adherent/surface-adapted micro-organisms in BAI, logically points to biomaterial surface-modifications for BAI-control. Biomaterial surface-modification is most suitable for prevention before adhering bacteria have grown into a mature biofilm, while BAI-treatment is virtually impossible through surface-modification. Hundreds of different surface-modifications have been proposed for BAI-control but few have passed clinical trials due to the statistical near-impossibility of benefit-demonstration. Yet, no biomaterial surface-modification forwarded, is clinically embraced. Collectively, this leads us to conclude that surface-modification is a dead-end road. Accepting that BAI is, like most human infections, due to surface-adherent biofilms (though not always to a foreign material), and regarding BAI as a common infection, opens a more-generally-applicable and therewith easier-to-validate road. Pre-clinical models have shown that stimuli-responsive nano-antimicrobials and antibiotic-loaded nanocarriers exhibit prolonged blood-circulation times and can respond to a biofilm's micro-environment to penetrate and accumulate within biofilms, prompt ROS-generation and synergistic killing with antibiotics of antibiotic-resistant pathogens without inducing further antimicrobial-resistance. Moreover, they can boost frustrated immune-cells around a biomaterial reducing the importance of this unique BAI-feature. Time to start exploring the nano-road for BAI-control.

Mechanisms and Barriers in Nanomedicine: Progress in the Field and Future Directions

In recent years, steady progress has been made in synthesizing and characterizing engineered nanoparticles, resulting in several approved drugs and multiple promising candidates in clinical trials. Regulatory agencies such as the Food and Drug Administration and the European Medicines Agency released important guidance documents facilitating nanoparticle-based drug product development, particularly in the context of liposomes and lipid-based carriers. Even with the progress achieved, it is clear that many barriers must still be overcome to accelerate translation into the clinic. At the recent conference workshop "Mechanisms and Barriers in Nanomedicine" in May 2023 in Colorado, U.S.A., leading experts discussed the formulation, physiological, immunological, regulatory, clinical, and educational barriers. This position paper invites open, unrestricted, nonproprietary discussion among senior faculty, young investigators, and students to trigger ideas and concepts to move the field forward.

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.

Platelet Membrane-Coated r-SAK Improves Thrombolytic Efficacy by Targeting Thrombus

Thrombolytic therapy is one of the most effective treatments for thrombus dissolution and recanalization of blocked vessels in thrombotic diseases. However, the application of the thrombolytic strategy has been limited due to unsatisfactory thrombolytic efficacy, relatively higher bleeding complications, and consequently restricted indications. Recombinant staphylokinase (r-SAK) is a third-generation thrombolytic agent produced by genetic engineering technology, which exhibits a better thrombolytic efficacy than urokinase and recombinant streptokinase. Inspired by the natural affinity of platelets in hemostasis and pathological thrombosis, we developed a platelet membrane (PM)-coated r-SAK (PM-r-SAK). Results from animal experiments and human in vitro studies showed that the PM-r-SAK had a thrombolytic efficacy equal to or better than its 4-fold dose of r-SAK. In a totally occluded rabbit femoral artery thrombosis model, the PM-r-SAK significantly shortened the initial recanalization time compared to the same dose and 4-fold dose of r-SAK. Regarding the recanalized vessels, the PM-r-SAK prolonged the time of reperfusion compared to the same dose and 4-fold dose of r-SAK, though the differences were not significant. An in vitro thrombolytic experiment demonstrated that the thrombolytic efficacy of PM-r-SAK could be inhibited by platelet-poor plasma from patients taking aspirin and ticagrelor. PM coating significantly improves the thrombolytic efficacy of r-SAK, which is related to the thrombus-targeting activity of the PM-r-SAK and can be inhibited by aspirin- and ticagrelor-treated plasma.

Multifunctional Fluoropolymer-Engineered Magnetic Nanoparticles to Facilitate Blood-Brain Barrier Penetration and Effective Gene Silencing in Medulloblastoma

Patients with brain cancers including medulloblastoma lack treatments that are effective long-term and without side effects. In this study, a multifunctional fluoropolymer-engineered iron oxide nanoparticle gene-therapeutic platform is presented to overcome these challenges. The fluoropolymers are designed and synthesized to incorporate various properties including robust anchoring moieties for efficient surface coating, cationic components to facilitate short interference RNA (siRNA) binding, and a fluorinated tail to ensure stability in serum. The blood-brain barrier (BBB) tailored system demonstrates enhanced BBB penetration, facilitates delivery of functionally active siRNA to medulloblastoma cells, and delivers a significant, almost complete block in protein expression within an in vitro extracellular acidic environment (pH 6.7) - as favored by most cancer cells. In vivo, it effectively crosses an intact BBB, provides contrast for magnetic resonance imaging (MRI), and delivers siRNA capable of slowing tumor growth without causing signs of toxicity - meaning it possesses a safe theranostic function. The pioneering methodology applied shows significant promise in the advancement of brain and tumor microenvironment-focused MRI-siRNA theranostics for the better treatment and diagnosis of medulloblastoma.

Exosome-Coated Prussian Blue Nanoparticles for Specific Targeting and Treatment of Glioblastoma

Glioblastoma is one of the most aggressive and invasive types of brain cancer with a 5-year survival rate of 6.8%. With limited options, patients often have poor quality of life and are moved to palliative care after diagnosis. As a result, there is an extreme need for a novel theranostic method that allows for early diagnosis and noninvasive treatment as current peptide-based delivery standards may have off-target effects. Prussian Blue nanoparticles (PBNPs) have recently been investigated as photoacoustic imaging (PAI) and photothermal ablation agents. However, due to their inability to cross the blood-brain barrier (BBB), their use in glioblastoma treatment is limited. By utilizing a hybrid, biomimetic nanoparticle composed of a PBNP interior and a U-87 cancer cell-derived exosome coating (Exo:PB), we show tumor-specific targeting within the brain and selective thermal therapy potential due to the strong photoconversion abilities. Particle characterization was carried out and showed a complete coating around the PBNPs that contains exosome markers. In vitro cellular uptake patterns are similar to native U-87 exosomes and when exposed to an 808 nm laser, show localized cell death within the specified region. After intravenous injection of Exo:PB into subcutaneously implanted glioblastoma mice, they have shown effective targeting and eradication of tumor volume compared to PEG-coated PBNPs (PEG:PB). Through systemic administration of Exo:PB particles into orthotopic glioblastoma-bearing mice, the PBNP signal was detected in the brain tumor region through PAI. It was seen that Exo:PB had preferential tumor accumulation with less off-targeting compared to the RGD:PB control. Ex vivo analysis validated specific targeting with a direct overlay of Exo:PB with the tumor by both H&E staining and Ki67 labeling. Overall, we have developed a novel biomimetic material that can naturally cross the BBB and act as a theranostic agent for systemic targeting of glioblastoma tissue and photothermal therapeutic effect.

Synthesis, characterization, pharmacological and computational evaluation of hyaluronic acid modified chebulinic acid encapsulated chitosan nanocomposite for cancer therapy

The purpose of this study was to produce hyaluronic acid customized nanoparticles with chitosan for the delivery of chebulinic acid (CLA) to enhance its anticancer potential against breast cancer. A significant portion of CLA was encapsulated (89.72 ± 4.38 %) and loaded (43.15 ± 5.61 %) within hybrid nanoparticles. The colloidal hybrid nanoparticles demonstrated a polydispersity index (PDI) of about 0.379 ± 0.112, with zeta capacitance of 32.69 ± 5.12 (mV), and an average size of 115 ± 8 (nm). It was found that CLA-CT-HA-NPs had stronger anticancer effects on MCF-7 cells (IC50 = 8.18 ± 3.02 μM) than pure CLA (IC50 = 17.15 ± 5.11 μM). The initial cytotoxicity findings were supported by additional investigations based on comet assay and flow cytometry analysis. Tumor remission and survival were evaluated in five separate groups of mice. When juxtaposed with pure CLA (3.17 ± 0.419 %), CLA-CT-HA-NPs improved survival rates and reduced tumor burden by 3.76 ± 0.811(%). Furthermore, in-silico molecular docking investigations revealed that various biodegradable polymers had several levels of compatibility with CLA. The outcomes of this study might potentially served as an effective strategy for delivering drugs in the context of breast cancer therapy.

All but Small: miRNAs from Wharton's Jelly-Mesenchymal Stromal Cell Small Extracellular Vesicles Rescue Premature White Matter Injury after Intranasal Administration

White matter injury (WMI) is a common neurological issue in premature-born neonates, often causing long-term disabilities. We recently demonstrated a key beneficial role of Wharton's jelly mesenchymal stromal cell-derived small extracellular vesicles (WJ-MSC-sEVs) microRNAs (miRNAs) in WMI-related processes in vitro. Here, we studied the functions of WJ-MSC-sEV miRNAs in vivo using a preclinical rat model of premature WMI. Premature WMI was induced in rat pups through inflammation and hypoxia-ischemia. Small EVs were purified from the culture supernatant of human WJ-MSCs. The capacity of WJ-MSC-sEV-derived miRNAs to decrease microglia activation and promote oligodendrocyte maturation was evaluated by knocking down (k.d) DROSHA in WJ-MSCs, releasing sEVs containing significantly less mature miRNAs. Wharton's jelly MSC-sEVs intranasally administrated 24 h upon injury reached the brain within 1 h, remained detectable for at least 24 h, significantly reduced microglial activation, and promoted oligodendrocyte maturation. The DROSHA k.d in WJ-MSCs lowered the therapeutic capabilities of sEVs in experimental premature WMI. Our results strongly indicate the relevance of miRNAs in the therapeutic abilities of WJ-MSC-sEVs in premature WMI in vivo, opening the path to clinical application.

Building CRISPR Gene Therapies for the Central Nervous System: A Review

Importance

Gene editing using clustered regularly interspaced short palindromic repeats (CRISPR) holds the promise to arrest or cure monogenic disease if it can be determined which genetic change to create without inducing unintended cellular dysfunction and how to deliver this technology to the target organ reliably and safely. Clinical trials for blood and liver disorders, for which delivery of CRISPR is not limiting, show promise, yet no trials have begun for central nervous system (CNS) indications.

Observations

The CNS is arguably the most challenging target given its innate exclusion of large molecules and its defenses against bacterial invasion (from which CRISPR originates). Herein, the types of CRISPR editing (DNA cutting, base editing, and templated repair) and how these are applied to different genetic variants are summarized. The challenges of delivering genome editors to the CNS, including the viral and nonviral delivery vehicles that may ultimately circumvent these challenges, are discussed. Also, ways to minimize the potential in vivo genotoxic effects of genome editors through delivery vehicle design and preclinical off-target testing are considered. The ethical considerations of germline editing, a potential off-target outcome of any gene editing therapy, are explored. The unique regulatory challenges of a human-specific therapy that cannot be derisked solely in animal models are also discussed.

Conclusions and Relevance

An understanding of both the potential benefits and challenges of CRISPR gene therapy better informs the scientific, clinical, regulatory, and timeline considerations of developing CRISPR gene therapy for neurologic diseases.

Functionalized Nanomaterials Capable of Crossing the Blood-Brain Barrier

The blood-brain barrier (BBB) is a specialized semipermeable structure that highly regulates exchanges between the central nervous system parenchyma and blood vessels. Thus, the BBB also prevents the passage of various forms of therapeutic agents, nanocarriers, and their cargos. Recently, many multidisciplinary studies focus on developing cargo-loaded nanoparticles (NPs) to overcome these challenges, which are emerging as safe and effective vehicles in neurotheranostics. In this Review, first we introduce the anatomical structure and physiological functions of the BBB. Second, we present the endogenous and exogenous transport mechanisms by which NPs cross the BBB. We report various forms of nanomaterials, carriers, and their cargos, with their detailed BBB uptake and permeability characteristics. Third, we describe the effect of regulating the size, shape, charge, and surface ligands of NPs that affect their BBB permeability, which can be exploited to enhance and promote neurotheranostics. We classify typical functionalized nanomaterials developed for BBB crossing. Fourth, we provide a comprehensive review of the recent progress in developing functional polymeric nanomaterials for applications in multimodal bioimaging, therapeutics, and drug delivery. Finally, we conclude by discussing existing challenges, directions, and future perspectives in employing functionalized nanomaterials for BBB crossing.

In silico exploration of venlafaxine, a potential non-tricyclic antidepressant in a liposomal formulation for nose-to-brain drug delivery

OBJECTIVE

Non-tricyclic antidepressants (non-TCAs) work by preventing the intake of norepinephrine and serotonin. Therefore, the aim of this study was to identify a potent non-TCAs and to develop liposomal formulation, characterize and to determine the drug release study across model of dialysis membrane via in vitro and in silico techniques.

METHODS

The in silico docking analysis identified venlafaxine (VLF) as the best non-TCAs with the depressant targets (PDB ID: 3PBL and 4BVN). VLF-loaded liposomal formulation was prepared by the thin-film hydration technique and characterized by physicochemical properties, including entrapment efficacy, in vitro drug release, particle size analysis, and FTIR. Moreover, this article also compares VLF and VLF-loaded with liposome carriers (LPs) based on nose-to-brain drug delivery approaches to treating depression.

RESULTS

Drug release profiles of the optimal liposomal formulation of VLF-LPs were examined in the high entrapment efficiency 94.13 ± 1.20% was attained at 224 nm, composed of spherical particles having a mean particle size of 191 ± 2.0 nm, a polydispersity index of 0.281 ± 0.06 and zeta potential of -20.3 mV. The best formulation of VLF-LPs was more effective than oral VLF treatment, as shown by the in vitro drug release data.

CONCLUSION

The results show that the VLF-LPs formulation is a promising potential platform for application in nose-to-brain drug delivery. Thus, highlighting the robustness of the intranasal drug delivery system with enhanced pharmaceutical properties, efficacy, and bioavailability for the anti-depression effect.

Rose bengal-encapsulated chitosan nanoparticles for the photodynamic treatment of Trichophyton species

Rose bengal (RB) solutions coupled with a green laser have proven to be efficient in clearing resilient nail infections caused by Trichophyton rubrum in a human pilot study and in extensive in vitro experiments. Nonetheless, the RB solution can become diluted or dispersed over the tissue and prevented from penetrating the nail plate to reach the subungual area where fungal infection proliferates. Nanoparticles carrying RB can mitigate the problem of dilution and are reported to effectively penetrate through the nail. For this reason, we have synthesized RB-encapsulated chitosan nanoparticles with a peak distribution size of ~200 nm and high reactive oxygen species (ROS) production. The RB-encapsulated chitosan nanoparticles aPDT were shown to kill more than 99% of T. rubrum, T. mentagrophytes, and T. interdigitale spores, which are the common clinically relevant pathogens in onychomycosis. These nanoparticles are not cytotoxic against human fibroblasts, which promotes their safe application in clinical translation.

Fabrication and evaluation of anticancer potential of diosgenin incorporated chitosan-silver nanoparticles; in vitro, in silico and in vivo studies

The discovery of effective therapeutic approaches with minimum side effects and their tendency to completely eradicate the disease is the main challenge in the history of cancer treatment. Fenugreek (FGK) seeds are a rich source of phytochemicals, especially Diosgenin (DGN), which shows outstanding anticancer activities. In the present study, chitosan-silver nanoparticles (ChAgNPs) containing Diosgenin (DGN-ChAgNPs) were synthesized and evaluated for their anticancer activity against breast cancer cell line (MCF-7). For the physical characterization, the hydrodynamic diameter and zeta potential of DGN-ChAgNPs were determined to be 160.4 ± 12 nm and +37.19 ± 5.02 mV, respectively. Transmission electron microscopy (TEM) showed that nanoparticles shape was mostly round with smooth edges. Moreover, DGN was efficiently entrapped in nanoformulation with good entrapment efficacy (EE) of ~88 ± 4 %. The in vitro anti-proliferative activity of DGN-ChAgNPs was performed by sulforhodamine B (SRB) assay with promising inhibitory concentration of 6.902 ± 2.79 μg/mL. DAPI staining, comet assay and flow cytometry were performed to validate the anticancer potential of DGN-ChAgNPs both qualitatively and quantitatively. The percentage of survival rate and tumor reduction weight was evaluated in vivo in different groups of mice. Cisplatin was used as a standard anticancer drug. The DGN-ChAgNPs (12.5 mg/kg) treated group revealed higher percentage of survival rate and tumor reduction weight as compared to pure DGN treated group. These findings suggest that DGN-ChAgNPs could be developed as potential treatment therapy for breast cancer.

Knowledge-Based Design of Multifunctional Polymeric Nanoparticles

Conventional drug delivery systems (DDS) today still face several drawbacks and obstacles. High total doses of active pharmaceutical ingredients (API) are often difficult or impossible to deliver due to poor solubility of the API or undesired clearance from the body caused by strong interactions with plasma proteins. In addition, high doses lead to a high overall body burden, in particular if they cannot be delivered specifically to the target site. Therefore, modern DDS must not only be able to deliver a dose into the body, but should also overcome the hurdles mentioned above as examples. One of these promising devices are polymeric nanoparticles, which can encapsulate a wide range of APIs despite having different physicochemical properties. Most importantly, polymeric nanoparticles are tunable to obtain tailored systems for each application. This can already be achieved via the starting material, the polymer, by incorporating, e.g., functional groups. This enables the particle properties to be influenced not only specifically in terms of their interactions with APIs, but also in terms of their general properties such as size, degradability, and surface properties. In particular, the combination of size, shape, and surface modification allows polymeric nanoparticles to be used not only as a simple drug delivery device, but also to achieve targeting. This chapter discusses to what extent polymers can be designed to form defined nanoparticles and how their properties affect their performance.

Nano biomaterials based strategies for enhanced brain targeting in the treatment of neurodegenerative diseases: an up-to-date perspective

Neurons and their connecting axons gradually degenerate in neurodegenerative diseases (NDs), leading to dysfunctionality of the neuronal cells and eventually their death. Drug delivery for the treatment of effected nervous system is notoriously complicated because of the presence of natural barriers, i.e., the blood-brain barrier and the blood cerebrospinal fluid barrier. Palliative care is currently the standard care for many diseases. Therefore, treatment programs that target the disease's origin rather than its symptoms are recommended. Nanotechnology-based drug delivery platforms offer an innovative way to circumvent these obstacles and deliver medications directly to the central nervous system, thereby enabling treatment of several common neurological problems, i.e., Alzheimer's, Parkinson's, Huntington's, and amyotrophic lateral sclerosis. Interestingly, the combination of nanomedicine and gene therapy enables targeting of selective mutant genes responsible for the progression of NDs, which may provide a much-needed boost in the struggle against these diseases. Herein, we discussed various central nervous system delivery obstacles, followed by a detailed insight into the recently developed techniques to restore neurological function via the differentiation of neural stem cells. Moreover, a comprehensive background on the role of nanomedicine in controlling neurogenesis via differentiation of neural stem cells is explained. Additionally, numerous phytoconstituents with their neuroprotective properties and molecular targets in the identification and management of NDs are also deliberated. Furthermore, a detailed insight of the ongoing clinical trials and currently marketed products for the treatment of NDs is provided in this manuscript.

Nanomedicines to treat rare neurological disorders: The case of Krabbe disease

The brain remains one of the most challenging therapeutic targets due to the low and selective permeability of the blood-brain barrier and complex architecture of the brain tissue. Nanomedicines, despite their relatively large size compared to small molecules and nucleic acids, are being heavily investigated as vehicles to delivery therapeutics into the brain. Here we elaborate on how nanomedicines may be used to treat rare neurodevelopmental disorders, using Krabbe disease (globoid cell leukodystrophy) to frame the discussion. As a monogenetic disorder and lysosomal storage disease affecting the nervous system, the lessons learned from examining nanoparticle delivery to the brain in the context of Krabbe disease can have a broader impact on the treatment of various other neurodevelopmental and neurodegenerative disorders. In this review, we introduce the epidemiology and genetic basis of Krabbe disease, discuss current in vitro and in vivo models of the disease, as well as current therapeutic approaches either approved or at different stage of clinical developments. We then elaborate on challenges in particle delivery to the brain, with a specific emphasis on methods to transport nanomedicines across the blood-brain barrier. We highlight nanoparticles for delivering therapeutics for the treatment of lysosomal storage diseases, classified by the therapeutic payload, including gene therapy, enzyme replacement therapy, and small molecule delivery. Finally, we provide some useful hints on the design of nanomedicines for the treatment of rare neurological disorders.

New insights toward molecular and nanotechnological approaches to antidiabetic agents for Alzheimer's disease

Alzheimer's disease (AD) is a chronic neurodegenerative disorder affecting a major class of silver citizens. The disorder shares a mutual relationship on account of its cellular and molecular pathophysiology with type-II diabetes mellitus (DM). Chronic DM increases the risk for AD. Emerging evidence recommended that resistance in insulin production develops cognitive dysfunction, which generally leads to AD. Repurposing of antidiabetic drugs can be effective in preventing and treatment of the neurodegenerative disorder. Limitations of antidiabetic drugs restrict the repurposing of the drugs for other disorders. Therefore, nanotechnological intervention plays a significant role in the treatment of neurological disorders. In this review, we discuss the common cellular and molecular pathophysiologies between AD and type-II DM, the relevance of in vivo models of type II DM in the study of AD, and the repurposing of antidiabetic drugs and the nanodelivery systems of antidiabetic drugs against AD.

Harnessing role of sesamol and its nanoformulations against neurodegenerative diseases

Sesamol is a lignan of sesame seeds and a natural phenolic molecule that has emerged as a useful medical agent. Sesamol is a non-toxic phytoconstituent, which exerts certain valuable effects in the management of cancer, diabetes, cardiovascular diseases, neurodegenerative diseases (NDs), etc. Sesamol is known to depict its neuroprotective role by various mechanisms, such as metabolic regulators, action on oxidative stress, neuroinflammation, etc. However, its poor oral bioavailability, rapid excretion (as conjugates), and susceptibility to gastric irritation/toxicity (particularly in rats' forestomach) may restrict its effectiveness. To overcome the associated limitations, novel drug delivery system-based formulations of sesamol are emerging and being researched extensively. These can conjugate with sesamol and enhance the bioavailability and solubility of free sesamol, along with delivery at the target site. In this review, we have summarized various research works highlighting the role of sesamol on various NDs, including Alzheimer's disease, Huntington's disease, Amyotrophic lateral sclerosis, and Parkinson's disease. Moreover, the formulation strategies and neuroprotective role of sesamol-based nano-formulations have also been discussed.

Current emerging novel therapies for Alzheimer's disease and the future prospects of magneto-mechanical force therapy

Alzheimer's disease (AD) is the most common neurodegenerative disease among the elderly, and the morbidity increases with the aging population aggravation. The clinical symptoms of AD mainly include cognitive impairment and memory loss, which undoubtedly bring a huge burden to families and society. Currently, the drugs in clinical use only improve the symptoms of AD but do not cure or prevent the progression of the disease. Therefore, it is urgent for us to develop novel therapeutic strategies for effective AD treatment. To provide a better theoretical basis for exploring novel therapeutic strategies in future AD treatment, this review introduces the recent AD treatment technologies from three aspects, including nanoparticle (NP) based drug therapy, biological therapy and physical therapy. The nanoparticle-mediated therapeutic approaches at the nanomaterial-neural interface and biological system are described in detail, and in particular the magneto-regulated strategies by magnetic field actuating magnetic nanoparticles are highlighted. Promising application of magneto-mechanical force regulated strategy in future AD treatment is also addressed, which offer possibilities for the remote manipulation in a precise manner. In the future, it may be possible for physicians to realize a remote, precise and effective therapy for AD using magneto-mechanical force regulated technology based on the combination of magnetic nanoparticles and an external magnetic field.

Novel Biocompatible Magnetoelectric MnFe2 O4 Core@BCZT Shell Nano-Hetero-Structures with Efficient Catalytic Performance

Magnetoelectric (ME) small-scale robotic devices attract great interest from the scientific community due to their unique properties for biomedical applications. Here, novel ME nano hetero-structures based on the biocompatible magnetostrictive MnFe2 O4 (MFO) and ferroelectric Ba0.85 Ca0.15 Zr0.1 Ti0.9 O3 (BCZT) are developed solely via the hydrothermal method for the first time. An increase in the temperature and duration of the hydrothermal synthesis results in increasing the size, improving the purity, and inducing morphology changes of MFO nanoparticles (NPs). A successful formation of a thin epitaxial BCZT-shell with a 2-5 nm thickness is confirmed on the MFO NPs (77 ± 14 nm) preliminarily treated with oleic acid (OA) or polyvinylpyrrolidone (PVP), whereas no shell is revealed on the surface of pristine MFO NPs. High magnetization is revealed for the developed ME NPs based on PVP- and OA-functionalized MFO NPs (18.68 ± 0.13 and 20.74 ± 0.22 emu g-1 , respectively). Moreover, ME NPs demonstrate 95% degradation of a model pollutant Rhodamine B within 2.5 h under an external AC magnetic field (150 mT, 100 Hz). Thus, the developed biocompatible core-shell ME NPs of MFO and BCZT can be considered as a promising tool for non-invasive biomedical applications, environmental remediation, and hydrogen generation for renewable energy sources.

Emerging strategies to fabricate polymeric nanocarriers for enhanced drug delivery across blood-brain barrier: An overview

Blood-brain barrier (BBB) serves as an essential interface between central nervous system (CNS) and its periphery, allowing selective permeation of ions, gaseous molecules, and other nutrients to maintain metabolic functions of brain. Concurrently, it restricts passage of unsolicited materials from bloodstream to CNS which could otherwise lead to neurotoxicity. Nevertheless, in the treatment of neurodegenerative diseases such as Parkinson's, Alzheimer's, diffuse intrinsic pontine glioma, and other brain cancers, drugs must reach CNS. Among various materials developed for this purpose, a few judiciously selected polymeric nanocarriers are reported to be highly prospective to facilitate BBB permeation. However, the challenge of transporting drug-loaded nanomaterials across this barrier remains formidable. Herein a concise analysis of recently employed strategies for designing polymeric nanocarriers to deliver therapeutics across BBB is presented. Impacts of 3Ss, namely, size, shape, and surface charge of polymeric nanocarriers on BBB permeation along with different ligands used for nanoparticle surface modification to achieve targeted delivery have been scrutinized. Finally, we elucidated future research directions in the context of designing smart polymeric nanocarriers for BBB permeation. This work aims to guide researchers engaged in polymeric nanocarrier design, helping them navigate where to begin, what challenges to address, and how to proceed effectively.

Influence of Surface Ligand Density and Particle Size on the Penetration of the Blood-Brain Barrier by Porous Silicon Nanoparticles

Overcoming the blood-brain barrier (BBB) remains a significant challenge with regard to drug delivery to the brain. By incorporating targeting ligands, and by carefully adjusting particle sizes, nanocarriers can be customized to improve drug delivery. Among these targeting ligands, transferrin stands out due to the high expression level of its receptor (i.e., transferrin receptor) on the BBB. Porous silicon nanoparticles (pSiNPs) are a promising drug nanocarrier to the brain due to their biodegradability, biocompatibility, and exceptional drug-loading capacity. However, an in-depth understanding of the optimal nanoparticle size and transferrin surface density, in order to maximize BBB penetration, is still lacking. To address this gap, a diverse library of pSiNPs was synthesized using bifunctional poly(ethylene glycol) linkers with methoxy or/and carboxyl terminal groups. These variations allowed us to explore different transferrin surface densities in addition to particle sizes. The effects of these parameters on the cellular association, uptake, and transcytosis in immortalized human brain microvascular endothelial cells (hCMEC/D3) were investigated using multiple in vitro systems of increasing degrees of complexity. These systems included the following: a 2D cell culture, a static Transwell model, and a dynamic BBB-on-a-chip model. Our results revealed the significant impact of both the ligand surface density and size of pSiNPs on their ability to penetrate the BBB, wherein intermediate-level transferrin densities and smaller pSiNPs exhibited the highest BBB transportation efficiency in vitro. Moreover, notable discrepancies emerged between the tested in vitro assays, further emphasizing the necessity of using more physiologically relevant assays, such as a microfluidic BBB-on-a-chip model, for nanocarrier testing and evaluation.

A erythrocyte-platelet hybrid membrane coated biomimetic nanosystem based on ginsenosides and PFH combined with ultrasound for targeted delivery in thrombus therapy

Thrombus is one of the culprits for global health problems. However, most current antithrombotic drugs are limited by restricted targeting ability and a high risk of systemic bleeding. A hybrid cell membrane-coated biomimetic nanosystem (PM/RM@PLGA@P/R) was constructed in this paper to fulfil the targeted delivery of ginsenoside (Rg1) and perfluorohexane (PFH). Poly lactic-co-glycolic acid (PLGA) is used as carriers to coat Rg1 and PFH. Thanks to the camouflage of erythrocyte membrane (RM) and platelet membrane (PM), the nanosystem in question possesses remarkable features including immune escape and self-targeting. Therefore, a compact nano-core with PLGA@P/R was formed, with a hybrid membrane covering the surface of the core, forming a "core-shell" structure. With its "core-shell" structure, this nanoparticle fancifully combines the advantages of both PFH (the low-intensity focused ultrasound (LIFU)-responsive phase-change thrombolysis) and Rg1(the antioxidant, anti-inflammatory and anticoagulant abilities). Meanwhile, PM/RM@PLGA@P/R nanoparticles exhibits superior in-vitro performance in terms of ROS scavenging, anticoagulant activity and immune escape compared with those without cell membranes (PLGA@P/R). Furthermore, in the animal experiment in which the tail vein thrombosis model was established by injecting k-carrageenan, the combined treatment of LIFU and PM/RM@PLGA@P/R showed a satisfactory antithrombotic efficiency (88.20 %) and a relatively higher biological safety level. This strategy provides new insights into the development of more effective and safer targeted biomimetic nanomedicines for antithrombotic treatments, possessing potential application in synergistic therapy field.

Role of Particle Size in Translational Research of Nanomedicines for Successful Drug Delivery: Discrepancies and Inadequacies

Despite significant research progress in substantiating the therapeutic merits of nanomedicines and the emergence of sophisticated nanotechnologies, the translation of this knowledge into new therapeutic modalities has been sluggish, indicating the need for a more comprehensive understanding of how the unique physicochemical properties of nanoparticles affect their clinical applications. Particle size is a critical quality attribute that impacts the bio-fate of nanoparticles, yet precise knowledge of its effect remains elusive with discrepancies among literature reports. This review aims to address this scientific knowledge gap from a drug development perspective by highlighting potential inadequacies during the evaluation of particle size effects. We begin with a discussion on the major issues in particle size characterization along with the corresponding remedies. The influence of confounding factors on biological effects of particle size, including colloidal stability, polydispersity, and in vitro drug release, are addressed for establishing stronger in vitro-in vivo correlation. Particle size design and tailoring approaches for successful nanoparticulate drug delivery beyond parenteral administration are also illustrated. We believe a holistic understanding of the effect of particle size on bio-fate, combined with consistent nanoparticle manufacturing platforms and tailored characterization techniques, would expedite the translation of nanomedicines into clinical practice.

Fabrication and Evaluation of Anticancer Potential of Eugenol Incorporated Chitosan-Silver Nanocomposites: In Vitro, In Vivo, and In Silico Studies

The expanding global cancer burden necessitates a comprehensive strategy to promote possible therapeutic interventions. Nanomedicine is a cutting-edge approach for treating cancer with minimal adverse effects. In the present study, chitosan-silver nanoparticles (ChAgNPs) containing Eugenol (EGN) were synthesized and evaluated for their anticancer activity against breast cancer cells (MCF-7). The physical, pharmacological, and molecular docking studies were used to characterize these nanoparticles. EGN had been effectively entrapped into hybrid NPs (84 ± 7%). The EGN-ChAgNPs had a diameter of 128 ± 14 nm, a PDI of 0.472 ± 0.118, and a zeta potential of 30.58 ± 6.92 mV. Anticancer activity was measured in vitro using an SRB assay, and the findings revealed that EGN-ChAgNPs demonstrated stronger anticancer activity against MCF-7 cells (IC50 = 14.87 ± 5.34 µg/ml) than pure EGN (30.72 ± 4.91 µg/ml). To support initial cytotoxicity findings, advanced procedures such as cell cycle analysis and genotoxicity were performed. Tumor weight reduction and survival rate were determined using different groups of mice. Both survival rates and tumor weight reduction were higher in the EGN-ChAgNPs (12.5 mg/kg) treated group than in the pure EGN treated group. Based on protein-ligand interactions, it might be proposed that eugenol had a favorable interaction with Aurora Kinase A. It was observed that C9 had the highest HYDE score of any sample, measuring at -6.8 kJ/mol. These results, in conjunction with physical and pharmacological evaluations, implies that EGN-ChAgNPs may be a suitable drug delivery method for treating breast cancer in a safe and efficient way.

Intranasal Nanotransferosomal Gel for Quercetin Brain Targeting: II. Antidepressant Effect in an Experimental Animal Model

Depression is a serious mental disorder and the most prevalent cause of disability and suicide worldwide. Quercetin (QER) demonstrated antidepressant effects in rats exhibiting anxiety and depressive-like behaviors. In an attempt to improve QER's antidepressant activity, a QER-loaded transferosome (QER-TFS) thermosensitive gel for intranasal administration was formulated and optimized. The therapeutic effectiveness of the optimized formulation was assessed in a depressed rat model by conducting a behavioral analysis. Behavioral study criteria such as immobility, swimming, climbing, sucrose intake, number of crossed lines, rearing, active interaction, and latency to feed were all considerably enhanced by intranasal treatment with the QER-TFS in situ gel in contrast to other formulations. A nasal histopathological study indicated that the QER-TFS thermosensitive gel was safe for the nasal mucosa. An immunohistochemical analysis showed that the animals treated with the QER-TFS thermosensitive gel had the lowest levels of c-fos protein expression, and brain histopathological changes in the depressed rats were alleviated. According to pharmacodynamic, immunohistochemical, and histopathological experiments, the intranasal administration of the QER-TFS thermosensitive gel substantially alleviated depressive symptoms in rats. However, extensive preclinical investigations in higher animal models are needed to anticipate its effectiveness in humans.

Analysis of bioactive compounds in cinnamon leaves and preparation of nanoemulsion and byproducts for improving Parkinson's disease in rats

Introduction

Cinnamomum osmophloeum Kanehira (C. osmophloeum), a broad-leaved tree species of Taiwan, contains phenolic acids, flavonoids, and phenylpropanoids such as cinnamaldehyde and cinnamic acid in leaves. Many reports have shown that the cinnamon leaf extract possesses anti-inflammatory, hypoglycemic, hypolipidemic and neuroprotective functions. This study aims to analyze bioactive compounds in C. osmophloeum (cinnamon leaves) by UPLC-MS/MS and prepare hydrosol, cinnamon leaf extract and cinnamon leaf nanoemulsion for comparison in improving Parkinson's disease (PD) in rats.

Methods

After extraction and determination of total phenolic and total flavonoid contents, cinnamaldehyde and the other bioactive compounds were analyzed in cinnamon leaves and hydrosol by UPLC-MS/MS. Cinnamon leaf nanoemulsion was prepared by mixing a suitable proportion of cinnamon leaf extract, soybean oil, lecithin, Tween 80 and deionized water, followed by characterization of particle size and polydispersity index by dynamic light scattering analyzer, particle size and shape by transmission electron microscope, encapsulation efficiency, as well as storage and heating stability. Fifty-six male Sprague-Dawley rats aged 8 weeks were divided into seven groups with group 1 as control (sunflower oil) and group 2 as induction (2 mg/kg bw rotenone in sunflower oil plus 10 mL/kg bw saline), while the other groups including rotenone injection (2 mg/kg bw) followed by high-dose of 60 mg/kg bw (group 3) or low-dose of 20 mg/kg bw (group 4) for tube feeding of cinnamon leaf extract or cinnamon leaf nanoemulsion at the same doses (groups 5 and 6) every day for 5 weeks as well as group 7 with rotenone plus hydrosol containing 0.5 g cinnamon leaf powder at a dose of 10 mL/kg bw. Biochemical analysis of brain tissue (striatum and midbrain) was done to determine dopamine, α-synuclein, tyrosine hydroxylase, superoxide dismutase, catalase, glutathione peroxidase and malondialdehyde contents by using commercial kits, while catalepsy performed by bar test.

Results and discussion

An extraction solvent of 80% ethanol was found to be the most optimal with a high yield of 15 bioactive compounds being obtained following UPLC analysis. A triple quadrupole tandem mass spectrometer with electrospray ionization mode was used for identification and quantitation, with cinnamaldehyde present at the highest amount (17985.2 µg/g). The cinnamon leaf nanoemulsion was successfully prepared with the mean particle size, zeta potential, polydispersity index and encapsulation efficiency being 30.1 nm, -43.1 mV, 0.149 and 91.6%, respectively. A high stability of cinnamon leaf nanoemulsion was shown over a 90-day storage period at 4 and heating at 100 for 2 h. Animal experiments revealed that the treatments of cinnamon leaf extract, nanoemulsion and hydrosol increased the dopamine contents from 17.08% to 49.39% and tyrosine hydroxylase levels from 17.07% to 25.59%, while reduced the α-synuclein levels from 17.56% to 15.95% in the striatum of rats. Additionally, in the midbrain of rats, an elevation of activities of superoxide dismutase (6.69-16.82%), catalase (8.56-16.94%), and glutathione peroxidase (2.09-16.94%) was shown, while the malondialdehyde content declined by 15.47-22.47%. Comparatively, the high-dose nanoemulsion exerted the most pronounced effect in improving PD in rats and may be a promising candidate for the development of health food or botanic drug.

Cutting-edge advances in modeling the blood-brain barrier and tools for its reversible permeabilization for enhanced drug delivery into the brain

The blood-brain barrier (BBB) is a sophisticated structure whose full functionality is required for maintaining the executive functions of the central nervous system (CNS). Tight control of transport across the barrier means that most drugs, particularly large size, which includes powerful biologicals, cannot reach their targets in the brain. Notwithstanding the remarkable advances in characterizing the cellular nature of the BBB and consequences of BBB dysfunction in pathology (brain metastasis, neurological diseases), it remains challenging to deliver drugs to the CNS. Herein, we outline the basic architecture and key molecular constituents of the BBB. In addition, we review the current status of approaches that are being explored to temporarily open the BBB in order to allow accumulation of therapeutics in the CNS. Undoubtedly, the major concern in field is whether it is possible to open the BBB in a meaningful way without causing negative consequences. In this context, we have also listed few other important key considerations that can improve our understanding about the dynamics of the BBB.

Theoretical design for covering Engeletin with functionalized nanostructure-lipid carriers as neuroprotective agents against Huntington's disease via the nasal-brain route

Objective: To propose a theoretical formulation of engeletin-nanostructured lipid nanocarriers for improved delivery and increased bioavailability in treating Huntington's disease (HD). Methods: We conducted a literature review of the pathophysiology of HD and the limitations of currently available medications. We also reviewed the potential therapeutic benefits of engeletin, a flavanol glycoside, in treating HD through the Keap1/nrf2 pathway. We then proposed a theoretical formulation of engeletin-nanostructured lipid nanocarriers for improved delivery across the blood-brain barrier (BBB) and increased bioavailability. Results: HD is an autosomal dominant neurological illness caused by a repetition of the cytosine-adenine-guanine trinucleotide, producing a mutant protein called Huntingtin, which degenerates the brain's motor and cognitive functions. Excitotoxicity, mitochondrial dysfunction, oxidative stress, elevated concentration of ROS and RNS, neuroinflammation, and protein aggregation significantly impact HD development. Current therapeutic medications can postpone HD symptoms but have long-term adverse effects when used regularly. Herbal medications such as engeletin have drawn attention due to their minimal side effects. Engeletin has been shown to reduce mitochondrial dysfunction and suppress inflammation through the Keap1/NRF2 pathway. However, its limited solubility and permeability hinder it from reaching the target site. A theoretical formulation of engeletin-nanostructured lipid nanocarriers may allow for free transit over the BBB due to offering a similar composition to the natural lipids present in the body a lipid solubility and increase bioavailability, potentially leading to a cure or prevention of HD. Conclusion: The theoretical formulation of engeletin-nanostructured lipid nanocarriers has the potential to improve delivery and increase the bioavailability of engeletin in the treatment of HD, which may lead to a cure or prevention of this fatal illness.

Functionalized nanoparticles crossing the brain-blood barrier to target glioma cells

Glioma is the most common tumor of the central nervous system (CNS), with a 5-year survival rate of <35%. Drug therapy, such as chemotherapeutic and immunotherapeutic agents, remains one of the main treatment modalities for glioma, including temozolomide, doxorubicin, bortezomib, cabazitaxel, dihydroartemisinin, immune checkpoint inhibitors, as well as other approaches such as siRNA, ferroptosis induction, etc. However, the filter function of the blood-brain barrier (BBB) reduces the amount of drugs needed to effectively target CNS tumors, making it one of the main reasons for poor drug efficacies in glioma. Thus, finding a suitable drug delivery platform that can cross the BBB, increase drug aggregation and retainment in tumoral areas and avoid accumulation in non-targeted areas remains an unsolved challenge in glioma drug therapy. An ideal drug delivery system for glioma therapy should have the following features: (1) prolonged drug life in circulation and effective penetration through the BBB; (2) adequate accumulation within the tumor (3) controlled-drug release modulation; (4) good clearance from the body without significant toxicity and immunogenicity, etc. In this regard, due to their unique structural features, nanocarriers can effectively span the BBB and target glioma cells through surface functionalization, providing a new and effective strategy for drug delivery. In this article, we discuss the characteristics and pathways of different nanocarriers for crossing the BBB and targeting glioma by listing different materials for drug delivery platforms, including lipid materials, polymers, nanocrystals, inorganic nanomaterials, etc.

Breast cancer brain metastasis: from etiology to state-of-the-art modeling

Currently, breast carcinoma is the most common form of malignancy and the main cause of cancer mortality in women worldwide. The metastasis of cancer cells from the primary tumor site to other organs in the body, notably the lungs, bones, brain, and liver, is what causes breast cancer to ultimately be fatal. Brain metastases occur in as many as 30% of patients with advanced breast cancer, and the 1-year survival rate of these patients is around 20%. Many researchers have focused on brain metastasis, but due to its complexities, many aspects of this process are still relatively unclear. To develop and test novel therapies for this fatal condition, pre-clinical models are required that can mimic the biological processes involved in breast cancer brain metastasis (BCBM). The application of many breakthroughs in the area of tissue engineering has resulted in the development of scaffold or matrix-based culture methods that more accurately imitate the original extracellular matrix (ECM) of metastatic tumors. Furthermore, specific cell lines are now being used to create three-dimensional (3D) cultures that can be used to model metastasis. These 3D cultures satisfy the requirement for in vitro methodologies that allow for a more accurate investigation of the molecular pathways as well as a more in-depth examination of the effects of the medication being tested. In this review, we talk about the latest advances in modeling BCBM using cell lines, animals, and tissue engineering methods.

Intranasally administered extracellular vesicles from human induced pluripotent stem cell-derived neural stem cells quickly incorporate into neurons and microglia in 5xFAD mice

Introduction

Extracellular vesicles (EVs) released by human-induced pluripotent stem cell (hiPSC)-derived neural stem cells (NSCs) have robust antiinflammatory and neurogenic properties due to therapeutic miRNAs and proteins in their cargo. Hence, hiPSC-NSC-EVs are potentially an excellent biologic for treating neurodegenerative disorders, including Alzheimer's disease (AD).

Methods

This study investigated whether intranasally (IN) administered hiPSC-NSC-EVs would quickly target various neural cell types in the forebrain, midbrain, and hindbrain regions of 3-month-old 5xFAD mice, a model of β-amyloidosis and familial AD. We administered a single dose of 25 × 10⁹ hiPSC-NSC-EVs labeled with PKH26, and different cohorts of naïve and 5xFAD mice receiving EVs were euthanized at 45 min or 6 h post-administration.

Results

At 45 min post-administration, EVs were found in virtually all subregions of the forebrain, midbrain, and hindbrain of naïve and 5xFAD mice, with predominant targeting and internalization into neurons, interneurons, and microglia, including plaque-associated microglia in 5xFAD mice. EVs also came in contact with the plasma membranes of astrocytic processes and the soma of oligodendrocytes in white matter regions. Evaluation of CD63/CD81 expression with the neuronal marker confirmed that PKH26 + particles found within neurons were IN administered hiPSC-NSC-EVs. At 6 h post-administration, EVs persisted in all cell types in both groups, with the distribution mostly matching what was observed at 45 min post-administration. Area fraction (AF) analysis revealed that, in both naïve and 5xFAD mice, higher fractions of EVs incorporate into forebrain regions at both time points. However, at 45 min post-IN administration, AFs of EVs within cell layers in forebrain regions and within microglia in midbrain and hindbrain regions were lower in 5xFAD mice than naïve mice, implying that amyloidosis reduces EV penetrance.

Discussion

Collectively, the results provide novel evidence that IN administration of therapeutic hiPSC-NSC-EVs is an efficient avenue for directing such EVs into neurons and glia in all brain regions in the early stage of amyloidosis. As pathological changes in AD are observed in multiple brain areas, the ability to deliver therapeutic EVs into various neural cells in virtually every brain region in the early stage of amyloidosis is attractive for promoting neuroprotective and antiinflammatory effects.

Efficacy of invasive and non-invasive methods for the treatment of Parkinson's disease: Nanodelivery and enriched environment

Parkinson's disease (PD) is the second most common neurodegenerative disorder characterised by the loss of dopaminergic neurons in the substantia nigra pars compacta and the subsequent motor disability. The most frequently used treatments in clinics, such as L-DOPA, restore dopaminergic neurotransmission in the brain. However, these treatments are only symptomatic, have temporary efficacy, and produce side effects. Part of the side effects are related to the route of administration as the consumption of oral tablets leads to unspecific pulsatile activation of dopaminergic receptors. For this reason, it is necessary to not only find alternative treatments, but also to develop new administration systems with better security profiles. Nanoparticle delivery systems are new administration forms designed to reach the pharmacological target in a highly specific way, leading to better drug bioavailability, efficacy and safety. Some of these delivery systems have shown promising results in animal models of PD not only when dopaminergic drugs are administered, but even more when neurotrophic factors are released. These latter compounds promote maturation and survival of dopaminergic neurons and can be exogenously administered in the form of pharmacological therapy or endogenously generated by non-pharmacological methods. In this sense, experimental exposure to enriched environments, a non-invasive strategy based on the combination of social and inanimate stimuli, enhances the production of neurotrophic factors and produces a neuroprotective effect in parkinsonian animals. In this review, we will discuss new nanodelivery systems in PD with a special focus on therapies that increase the release of neurotrophic factors.

DectiSomes: C-type lectin receptor-targeted liposomes as pan-antifungal drugs

Combatting the ever-increasing threat from invasive fungal pathogens faces numerous fundamental challenges, including constant human exposure to large reservoirs of species in the environment, the increasing population of immunocompromised or immunosuppressed individuals, the unsatisfactory efficacy of current antifungal drugs and their associated toxicity, and the scientific and economic barriers limiting a new antifungal pipeline. DectiSomes represent a new drug delivery platform that enhances antifungal efficacy for diverse fungal pathogens and reduces host toxicity for current and future antifungals. DectiSomes employ pathogen receptor proteins - C-type lectins - to target drug-loaded liposomes to conserved fungal cognate ligands and away from host cells. DectiSomes represent one leap forward for urgently needed effective pan-antifungal therapy. Herein, we discuss the problems of battling fungal diseases and the state of DectiSome development.

Colloidal Perspective on Targeted Drug Delivery to the Central Nervous System

This article describes a new approach in targeted drug delivery to the central nervous system (CNS) in a significant departure from the predominant systematic drug administration attempting to penetrate the blood-brain barrier (BBB). Nanoparticles chemically conjugated to neural tract tracer proteins are capable of path-specific axonal retrograde transport, transneuronal transport, and anatomical tract flow to bypass the BBB. To celebrate the work by Dr. Bettye Washington Greene on the physical chemistry of colloidal particles, this article focuses on the physiochemical characteristics of the nanoparticles, various colloidal forces that impact the colloidal stability of nanoparticles in biological media, and surface chemistry strategies to avoid nanoparticle aggregation-induced poor therapeutic outcomes. The biological environment for the anatomical retrograde transport of neural tract tracers is examined to directly link factors impacting the colloidal stability of the new class of CNS-targeting nanoconjugates such as nanoconjugate size, shape, surface charge, surface chemistry, ionic strength, pH, and protein adsorption on the nanoparticle. We conclude with opportunities and challenges for future research.

In-vivo time course of organ uptake and blood-brain-barrier permeation of poly(L-lactide) and poly(perfluorodecyl acrylate) nanoparticles with different surface properties in unharmed and brain-traumatized rats

Background

Traumatic brain injury (TBI) has a dramatic impact on mortality and quality of life and the development of effective treatment strategies is of great socio-economic relevance. A growing interest exists in using polymeric nanoparticles (NPs) as carriers across the blood-brain barrier (BBB) for potentially effective drugs in TBI. However, the effect of NP material and type of surfactant on their distribution within organs, the amount of the administrated dose that reaches the brain parenchyma in areas with intact and opened BBB after trauma, and a possible elicited inflammatory response are still to be clarified.

Methods

The organ distribution, BBB permeation and eventual inflammatory activation of polysorbate-80 (Tw80) and sodiumdodecylsulfate (SDS) stabilized poly(L-lactide) (PLLA) and poly(perfluorodecyl acrylate) (PFDL) nanoparticles were evaluated in rats after intravenous administration. The NP uptake into the brain was assessed under intact conditions and after controlled cortical impact (CCI).

Results

A significantly higher NP uptake at 4 and 24 h after injection was observed in the liver and spleen, followed by the brain and kidney, with minimal concentrations in the lungs and heart for all NPs. A significant increase of NP uptake at 4 and 24 h after CCI was observed within the traumatized hemisphere, especially in the perilesional area, but NPs were still found in areas away from the injury site and the contralateral hemisphere. NPs were internalized in brain capillary endothelial cells, neurons, astrocytes, and microglia. Immunohistochemical staining against GFAP, Iba1, TNFα, and IL1β demonstrated no glial activation or neuroinflammatory changes.

Conclusions

Tw80 and SDS coated biodegradable PLLA and non-biodegradable PFDL NPs reach the brain parenchyma with and without compromised BBB by TBI, even though a high amount of NPs are retained in the liver and spleen. No inflammatory reaction is elicited by these NPs within 24 h after injection. Thus, these NPs could be considered as potentially effective carriers or markers of newly developed drugs with low or even no BBB permeation.

Nanomedicine based strategies for oligonucleotide traversion across the blood-brain barrier

Neurological disorders are considered the most prominent cause of disability worldwide. The major hurdle in the management of neurological disorders is the existence of the blood-brain barrier (BBB), which hinders the entry of several therapeutic moieties. In recent years, oligonucleotides have gained tremendous attention for their target specificity, diminished dose and adverse effects, thereby halting disease progression. However, enzymatic degradation, rapid clearance, limited circulation and availability at the bio-active site, etc., limit its clinical translation. Nanomedicine has opened up a breadth of opportunities in the delivery of oligonucleotides across the BBB. This review addresses the pitfalls associated with oligonucleotide delivery in traversing the BBB via nanotherapeutics for the management of brain disorders. Regulatory perspectives pertaining to hastening the clinical translation of oligonucleotide-loaded nanocarriers for brain delivery have been highlighted.

Parenteral Lipid-Based Nanoparticles for CNS Disorders: Integrating Various Facets of Preclinical Evaluation towards More Effective Clinical Translation

Contemporary trends in combinatorial chemistry and the design of pharmaceuticals targeting brain disorders have favored the development of drug candidates with increased lipophilicity and poorer water solubility, with the expected improvement in delivery across the blood-brain barrier (BBB). The growing availability of innovative excipients/ligands allowing improved brain targeting and controlled drug release makes the lipid nanocarriers a reasonable choice to overcome the factors impeding drug delivery through the BBB. However, a wide variety of methods, study designs and experimental conditions utilized in the literature hinder their systematic comparison, and thus slows the advances in brain-targeting by lipid-based nanoparticles. This review provides an overview of the methods most commonly utilized during the preclinical testing of liposomes, nanoemulsions, solid lipid nanoparticles and nanostructured lipid carriers intended for the treatment of various CNS disorders via the parenteral route. In order to fully elucidate the structure, stability, safety profiles, biodistribution, metabolism, pharmacokinetics and immunological effects of such lipid-based nanoparticles, a transdisciplinary approach to preclinical characterization is mandatory, covering a comprehensive set of physical, chemical, in vitro and in vivo biological testing.

Nanotechnology: A Promising Targeted Drug Delivery System for Brain Tumours and Alzheimer's Disease

Nanotechnology is the process of modulating shape and size at the nanoscale to design and manufacture structures, devices, and systems. Nanotechnology's prospective breakthroughs are incredible, and some cannot even be comprehended right now. The blood-brain barrier, which is a prominent physiological barrier in the brain, limits the adequate elimination of malignant cells by changing the concentration of therapeutic agents at the target tissue. Nanotechnology has sparked interest in recent years as a way to solve these issues and improve drug delivery. Inorganic and organic nanomaterials have been found to be beneficial for bioimaging approaches and controlled drug delivery systems. Brain cancer (BC) and Alzheimer's disease (AD) are two of the prominent disorders of the brain. Even though the pathophysiology and pathways for both disorders are different, nanotechnology with common features can deliver drugs over the BBB, advancing the treatment of both disorders. This innovative technology could provide a foundation for combining diagnostics, treatments, and delivery of targeted drugs to the tumour site, further supervising the response and designing and delivering materials by employing atomic and molecular elements. There is currently limited treatment for Alzheimer's disease, and reversing further progression is difficult. Recently, various nanocarriers have been investigated to improve the bioavailability and efficacy of many AD treatment drugs. Nanotechnology-assisted drugs can penetrate the BBB and reach the target tissue. However, further research is required in this field to ensure the safety and efficacy of drug-loaded nanoparticles. The application of nanotechnology in the diagnosis and treatment of brain tumours and Alzheimer's disease is briefly discussed in this review.

Oxidative Stress and Mitochondrial Dysfunction in Chronic Kidney Disease

The kidney contains many mitochondria that generate ATP to provide energy for cellular processes. Oxidative stress injury can be caused by impaired mitochondria with excessive levels of reactive oxygen species. Accumulating evidence has indicated a relationship between oxidative stress and kidney diseases, and revealed new insights into mitochondria-targeted therapeutics for renal injury. Improving mitochondrial homeostasis, increasing mitochondrial biogenesis, and balancing mitochondrial turnover has the potential to protect renal function against oxidative stress. Although there are some reviews that addressed this issue, the articles summarizing the relationship between mitochondria-targeted effects and the risk factors of renal failure are still few. In this review, we integrate recent studies on oxidative stress and mitochondrial function in kidney diseases, especially chronic kidney disease. We organized the causes and risk factors of oxidative stress in the kidneys based in their mitochondria-targeted effects. This review also listed the possible candidates for clinical therapeutics of kidney diseases by modulating mitochondrial function.

Transmigration of magnetite nanoparticles across the blood-brain barrier in a rodent model: influence of external and alternating magnetic fields

Despite advances in neurology, drug delivery to the central nervous system is considered a challenge due to the presence of the blood brain barrier (BBB). In this study, the role of magnetic hyperthermia induced by exposure of magnetic nanoparticles (MNPs) to an alternating magnetic field (AMF) in synergy with an external magnetic field (EMF) was investigated to transiently increase the permeability of the MNPs across the BBB. A dual magnetic targeting approach was employed by first dragging the MNPs by an EMF for an intended enhanced cellular association with the brain endothelial cells and then activating the MNPs by an AMF for the temporary disruption of the tight junctions of BBB. The efficacy of the BBB permeability for the MNPs under the influence of dual magnetic targeting was evaluated in vitro using transwell models developed by co-culturing murine brain endothelial cells with astrocytes, as well as in vivo in mouse models. The in vitro results revealed that the exposure to AMF transiently opened the tight junctions at the BBB, which, after 3 h of treatment, were observed to recover back to their comparable control levels. A biodistribution analysis of nanoparticles confirmed targeted accumulation of MNPs in the brain following dual targeting. This dual targeting approach was observed to open the tight junctions, thus increasing the transport of MNPs into the brain with higher specificity as compared to using EMF targeting alone, suggesting that a dual magnetic targeting-induced transport of MNPs across the BBB is an effective measure for delivery of therapeutics.

Penetration and translocation of functional inorganic nanomaterials into biological barriers

With excellent physicochemical properties, inorganic nanomaterials (INMs) have exhibited a series of attractive applications in biomedical fields. Biological barriers prevent successful delivery of nanomedicine in living systems that limits the development of nanomedicine especially for sufficient delivery of drugs and effective therapy. Numerous researches have focused on overcoming these biological barriers and homogeneity of organisms to enhance therapeutic efficacy, however, most of these strategies fail to resolve these challenges. In this review, we present the latest progress about how INMs interact with biological barriers and penetrate these barriers. We also summarize that both native structure and components of biological barriers and physicochemical properties of INMs contributed to the penetration capacity. Knowledge about the relationship between INMs structure and penetration capacity will guide the design and application of functional and efficient nanomedicine in the future.

Increased brain uptake of pterostilbene loaded folate modified micellar delivery system

Effective chemotherapy for clinical treatment of brain diseases is still lacking due to the poor penetration of the blood-brain barrier (BBB). The aim of this study was to construct a folate modified pterostilbene (Pt) loaded polymeric micellar delivery system (F-Pt/M) with mPEG-PCL as carrier material to aim at penetrating the BBB for brain tissue targeting via receptor-mediated endocytosis. In this study, F-Pt/M was prepared using thin-film hydration method and then optimized by response surface methodology (RSM) with the entrapment efficiency (EE), drug loading (DL) and hydrodynamic diameter (HD) as indexes. The average hydrodynamic diameter and zeta potential of optimal F-Pt/M were 133.2 nm and 24.6 mV, respectively. DL (18.3%) and EE (98.6%) made the solubility of Pt in water about 25 times higher than that of crude Pt. Results of DSC evaluation revealed that drugs were successfully encapsulated inside the polymeric micelles. TEM images showed that homogeneous spherical micellar structures with a narrow size distribution were developed. The release result in vitro showed that F-Pt/M presented sustained release behavior compared to control free Pt solution. Compared to non-targeted Pt/M, F-Pt/M had a significantly higher cytotoxicity against FR-overexpressing A172 cells. In vitro cellular uptake tests illustrated that the micellar delivery system could significantly improve the accumulation of drugs in target cells via receptor-mediated endocytosis. BBB penetration value (P) of F-Pt/M was about 4 folds higher than that of free Pt group. In addition, drug targeting index (DTI) was calculated to determine targeting of F-Pt/M to the brain which was found to be 4.89, implying improved brain targeting was achieved. Hence, the developed F-Pt/M exhibited great potential for delivering more drug molecules across the BBB for the treatment of brain diseases.

Carboxymethyl-Dextran-Coated Superparamagnetic Iron Oxide Nanoparticles for Drug Delivery: Influence of the Coating Thickness on the Particle Properties

Carboxymethyl-dextran (CMD)-coated iron oxide nanoparticles (IONs) are of great interest in nanomedicine, especially for applications in drug delivery. To develop a magnetically controlled drug delivery system, many factors must be considered, including the composition, surface properties, size and agglomeration, magnetization, cytocompatibility, and drug activity. This study reveals how the CMD coating thickness can influence these particle properties. ION@CMD are synthesized by co-precipitation. A higher quantity of CMD leads to a thicker coating and a reduced superparamagnetic core size with decreasing magnetization. Above 12.5−25.0 g L−1 of CMD, the particles are colloidally stable. All the particles show hydrodynamic diameters < 100 nm and a good cell viability in contact with smooth muscle cells, fulfilling two of the most critical characteristics of drug delivery systems. New insights into the significant impact of agglomeration on the magnetophoretic behavior are shown. Remarkable drug loadings (62%) with the antimicrobial peptide lasioglossin and an excellent efficiency (82.3%) were obtained by covalent coupling with the EDC/NHS (N-ethyl-N′-(3-(dimethylamino)propyl)carbodiimide/N-hydroxysuccinimide) method in comparison with the adsorption method (24% drug loading, 28% efficiency). The systems showed high antimicrobial activity with a minimal inhibitory concentration of 1.13 µM (adsorption) and 1.70 µM (covalent). This system successfully combines an antimicrobial peptide with a magnetically controllable drug carrier.

Antibody Delivery into the Brain by Radiosensitizer Nanoparticles for Targeted Glioblastoma Therapy

Background

Glioblastoma is the most lethal primary brain malignancy in adults. Standard of care treatment, consisting of temozolomide (TMZ) and adjuvant radiotherapy (RT), mostly does not prevent local recurrence. The inability of drugs to enter the brain, in particular antibody-based drugs and radiosensitizers, is a crucial limitation to effective glioblastoma therapy.

Methods

Here, we developed a combined strategy using radiosensitizer gold nanoparticles coated with insulin to cross the blood-brain barrier and shuttle tumor-targeting antibodies (cetuximab) into the brain.

Results

Following intravenous injection to an orthotopic glioblastoma mouse model, the nanoparticles specifically accumulated within the tumor. Combining targeted nanoparticle injection with TMZ and RT standard of care significantly inhibited tumor growth and extended survival, as compared to standard of care alone. Histological analysis of tumors showed that the combined treatment eradicated tumor cells, and decreased tumor vascularization, proliferation, and repair.

Conclusions

Our findings demonstrate radiosensitizer nanoparticles that effectively deliver antibodies into the brain, target the tumor, and effectively improve standard of care treatment outcome in glioblastoma.

"Targeting Design" of Nanoparticles in Tumor Therapy

Tumor-targeted therapy based on nanoparticles is a popular research direction in the biomedical field. After decades of research and development, both the passive targeting ability of the inherent properties of NPs and the active targeting based on ligand receptor interaction have gained deeper understanding. Unfortunately, most targeted delivery strategies are still in the preclinical trial stage, so it is necessary to further study the biological fate of particles in vivo and the interaction mechanism with tumors. This article reviews different targeted delivery strategies based on NPs, and focuses on the physical and chemical properties of NPs (size, morphology, surface and intrinsic properties), ligands (binding number/force, activity and species) and receptors (endocytosis, distribution and recycling) and other factors that affect particle targeting. The limitations and solutions of these factors are further discussed, and a variety of new targeting schemes are introduced, hoping to provide guidance for future targeting design and achieve the purpose of rapid transformation of targeted particles into clinical application.

Biopolymer Nanoparticles for Nose-to-Brain Drug Delivery: A New Promising Approach for the Treatment of Neurological Diseases

Diseases affecting the central nervous system (CNS) are among the most disabling and the most difficult to cure due to the presence of the blood–brain barrier (BBB) which represents an impediment from a therapeutic and diagnostic point of view as it limits the entry of most drugs. The use of biocompatible polymer nanoparticles (NPs) as vehicles for targeted drug delivery to the brain arouses increasing interest. However, the route of administration of these vectors remains critical as the drug must be delivered without being degraded to achieve a therapeutic effect. An innovative approach for the administration of drugs to the brain using polymeric carriers is represented by the nose-to-brain (NtB) route which involves the administration of the therapeutic molecule through the neuro-olfactory epithelium of the nasal mucosa. Nasal administration is a non-invasive approach that allows the rapid transport of the drug directly to the brain and minimizes its systemic exposure. To date, many studies involve the use of polymer NPs for the NtB transport of drugs to the brain for the treatment of a whole series of disabling neurological diseases for which, as of today, there is no cure. In this review, various types of biodegradable polymer NPs for drug delivery to the brain through the NtB route are discussed and particular attention is devoted to the treatment of neurological diseases such as Glioblastoma and neurodegenerative diseases.

Multimodal targeting of glioma with functionalized nanoparticles

The most common and aggressive primitive intracranial tumor of the central nervous system is the glioma. The blood–brain barrier (BBB) has proven to be a significant obstacle to the effective treatment of glioma. To effectively treat glioma, different ways have been used to cross the BBB to deliver drugs to the brain. Drug delivery through nanocarriers proves to be an effective and non-invasive technique for the treatment of glioma and has great potential in the treatment of glioma. In this review, we will provide an overview of nanocarrier-mediated drug delivery and related glioma therapy. Nanocarrier-mediated drug delivery techniques to cross the BBB (liposomes, micelles, inorganic systems, polymeric nanoparticles, nanogel system, and biomimetic nanoparticles) are explored. Finally, the use of nanotherapeutic approaches in the treatment of glioblastoma including chemotherapy, radiotherapy, photothermal therapy, gene therapy, glioma genome editing, immunotherapy, chimeric antigen receptor (CAR) T-cells, immune checkpoint modulators, immune photothermal therapy, vaccine-based immunotherapy, and combination therapy is summarized. Furthermore, this article offers various views on the clinical applicability of nanomedicine.