Nanoparticulate systems for brain delivery of drugs

Brain Targeting Nanomedicines: Pitfalls and Promise

Brain diseases are the most devastating problem among the world's increasingly aging population, and the number of patients with neurological diseases is expected to increase in the future. Although methods for delivering drugs to the brain have advanced significantly, none of these approaches provide satisfactory results for the treatment of brain diseases. This remains a challenge due to the unique anatomy and physiology of the brain, including tight regulation and limited access of substances across the blood-brain barrier. Nanoparticles are considered an ideal drug delivery system to hard-to-reach organs such as the brain. The development of new drugs and new nanomaterial-based brain treatments has opened various opportunities for scientists to develop brain-specific delivery systems that could improve treatment outcomes for patients with brain disorders such as Alzheimer's disease, Parkinson's disease, stroke and brain tumors. In this review, we discuss noteworthy literature that examines recent developments in brain-targeted nanomedicines used in the treatment of neurological diseases.

Nano Lipid Carriers as a Promising Drug Delivery Carrier for Neurodegenerative Disorders - An Overview of Recent Advances

The last few decades have seen a rise in the number of deaths caused by neurological disorders. The blood-brain barrier (BBB), which is very complex and has multiple mechanisms, makes drug delivery to the brain challenging for many scientists. Lipid nanoparticles (LNPs) such as nanoemulsions, solid-lipid nanoparticles, liposomes, and nano lipid carriers (NLCs) exhibit enhanced bioavailability and flexibility among these nanocarriers. NLCs are found to be very effective. In the last few decades, they have been a center of attraction for controlled drug delivery. According to the current global status of specific neurological disorders, out of all LNPs, NLC significantly reduces the cross-permeability of drugs through the BBB due to their peculiar properties. They offer a host of advantages over other carriers because of their biocompatibility, safety, non-toxicity, non-irritating behavior, stability, high encapsulation efficiency, high drug loading, high drug targeting, control of drug release, and ease in manufacturing. The biocompatible lipid matrix is ideally suited as a drug carrier system due to the nano-size range. For certain neurological conditions such as Parkinsonism, Alzheimer's, Epilepsy, Multiple sclerosis, and Brain cancer, we examined recent advances in NLCs to improve brain targeting of bioactive with special attention to formulation aspects and pharmacokinetic characteristics. This article also provides a brief overview of a critical approach for brain targeting, i.e., direct nose-to-brain drug delivery and some recent patents published on NLC".

Polysorbate 80 surface modified SLNs of formoterol suppress SNCA gene and mitochondrial oxidative stress in mice model of Parkinson's disease

The present study hypothesises that the selective brain β2 receptor activation through β2-adrenoreceptor agonist (β2ARA), Formoterol (FMT), suppresses SNCA gene expression, a pathological hallmark of Parkinson's disease (PD) in brain. Further, it is also hypothesized that brain targeted delivery of Formoterol via polysorbate-80 surface modified solid lipid nanoparticles of Formoterol (FMT-SLNs-PS80) can improve its stability, therapeutic efficacy and avoid/reduce peripheral off-target side effects. FMT-SLNs-PS80 was prepared by solvent injection method, the formulation was optimized by using Box-Behnken design and characterized by measuring drug content, entrapment efficacy, particle size, zeta potentials and poly dispersibility. The FMT-SLNs-PS80, significantly decreases the SNCA expression, mitochondrial membrane damage and rotenone induced changes in oxidative (SOD, CAT, GSH and ROS) stress markers in SH-SY5Y cell lines. The ex vivo permeation study of the formulation using everted chicken ileum exhibited a steady state flux. The pharmacokinetic and tissue distribution studies of the formulation in rats showed a significant improvement in the kinetic parameters when compared to naïve FMT, further the formulation also improved the brain bioavailability of FMT. The anti-Parkinson's efficacy studies of the formulation in mice showed a significant neuroprotection against rotenone-induced changes in behavioural and biochemical parameters. Further, the histopathological analysis of mice brain confirms a significant neuroprotective benefit. The present study successfully establishes the brain targeted delivery and anti-Parkinson's therapeutic efficacy of FMT-SLNs-PS80.

Polysorbate 80 surface modified PLGA nanoparticles: an in-vitro evaluation of cellular uptake and cytotoxicity on neuro-2a cells

AIM

Present study focuses on the development of P80 coated PLGA Nanoparticles loaded with drugs, paroxetine (P80-Par-PLGA-NPs) and clonidine (P80-CLD-PLGA-NPs) for in-vitro evaluation of Cellular Uptake & Cytotoxicity on Neuro-2a cells.

METHOD

P80-Par-PLGA-NPs and P80-CLD-PLGA-NPs were developed and characterised for zeta size, potential, PDI, EE%, DL%, TEM, SEM, FTIR, DSC, in-vitro release, cytotoxicity, histopathological and cell uptake studies using rhodamine loaded P80-NPs.

RESULT

Mean particle diameter of P80-Par-PLGA-NPs and P80-CLD-PLGA-NPs was 204; 182.7 nm, ZP of -21.8; -18.72 mV and 0.275; 0.341 PDI, respectively. TEM and SEM images revealed homogenous surface morphology. In-vitro drug release showed sustained and complete release in 72 h. Cell viability (>90%) at Cmax and no cytotoxicity in histopathology was observed. Significant higher uptake (96.9%) of P80-modified-NPS was observed as compared to unmodified-NPs (81%) (p < 0.05).

CONCLUSION

The finding clearly indicated a higher cell uptake of drugs via surface modified P80-coated PLGA-NPs as compared to unmodified particles.

Development and in vitro evaluation of carmustine delivery platform: A hypoxia-sensitive anti-drug resistant nanomicelle with BBB penetrating ability

Glioma is extremely difficult to be completely excised by surgery due to its invasive nature. Thus, chemotherapy still is the mainstay in the treatment of glioma after surgery. However, the natural blood-brain barrier (BBB) greatly restricts the penetration of chemotherapeutic agents into the central nervous system. As a front-line anti-glioma agent in clinical, carmustine (BCNU) exerts antitumor effect by inducing DNA damage at the O6 position of guanine. However, the therapeutic effect of BCNU was largely decreased because of the drug resistance mediated by O6-alkylguanine-DNA alkyltransferase (AGT) and insufficient local drug concentrations. To overcome these obstacles, we synthesized a BCNU-loaded hypoxia-responsive nano-micelle with BBB penetrating capacity and AGT inhibitory activity, named as T80-HA-AZO-BG/BCNU NPs. In this nano-system, Tween 80 (T80) serves as a functional coating on the surface of the micelle, promoting transportation across the BBB. Hyaluronic acid (HA) with active tumor-targeting capability was linked with the hydrophobic O6-benzylguanine (BG) analog via a hypoxia-sensitive azo bond. Under hypoxic tumor microenvironment, the azo bond selectively breaks to release O6-BG as AGT inhibitor and BCNU as DNA alkylating agent. The synthesized T80-HA-AZO-BG/BCNU NPs showed good stability, favorable biocompatibility and hypoxia-responsive drug-releasing ability. T80 modification improved the transportation of the micelle across an in vitro BBB model. Moreover, T80-HA-AZO-BG/BCNU NPs exhibited significantly enhanced cytotoxicity against glioma cell lines with high AGT expression compared with traditional combined medication of BCNU plus O6-BG. We expect that the tumor-targeting nano-micelle designed for chloroethylnitrosourea will provide new tools for the development of effective glioma therapy.

Microparticles and nanoparticles-based approaches to improve oral treatment of Helicobacter pylori infection

Helicobacter pylori is a gram-negative, spiral-shaped, flagellated bacterium that colonizes the stomach of half the world's population. Helicobacter pylori infection causes pathologies of varying severity. Standard oral therapy fails in 15-20% since the barriers of the oral route decrease the bioavailability of antibiotics and the intrinsic factors of bacteria increase the rates of resistance. Nanoparticles and microparticles are promising strategies for drug delivery into the gastric mucosa and targeting H. pylori. The variety of building blocks creates systems with distinct colloidal, surface, and biological properties. These features improve drug-pathogen interactions, eliminate drug depletion and overuse, and enable the association of multiple actives combating H. pylori on several fronts. Nanoparticles and microparticles are successfully used to overcome the barriers of the oral route, physicochemical inconveniences, and lack of selectivity of current therapy. They have proven efficient in employing promising anti-H. pylori compounds whose limitation is oral route instability, such as some antibiotics and natural products. However, the current challenge is the applicability of these strategies in clinical practice. For this reason, strategies employing a rational design are necessary, including in the development of nano- and microsystems for the oral route.

RNA nanotechnology: A new chapter in targeted therapy

Nanoparticles have been widely studied in the fields of biotechnology, pharmacy, optics and medicine and have broad application prospects. Numerous studies have shown significant interest in utilizing nanoparticles for chemically coating or coupling drugs, aiming to address the challenges of drug delivery, including degradability and uncertainty. Furthermore, the utilization of lipid nanoparticles loaded with novel coronavirus antigen mRNA to control the COVID-19 pandemic has led to a notable surge in research on nanoparticle vaccines. Hence, nanoparticles have emerged as a crucial delivery system for disease prevention and treatment, bearing immense significance. Current research highlights that nanoparticles offer superior efficacy and potential compared to conventional drug treatment and prevention methods. Notably, for drug delivery applications, it is imperative to utilize biodegradable nanoparticles. This paper reviews the structures and characteristics of various biodegradable nanoparticles and their applications in biomedicine in order to inspire more researchers to further explore the functions of nanoparticles. RNA plays a pivotal role in regulating the occurrence and progression of diseases, but its inherent susceptibility to degradation poses a challenge. In light of this, we conducted a comprehensive review of the research advancements concerning RNA-containing biodegradable nanoparticles in the realm of disease prevention and treatment, focusing on cancer, inflammatory diseases, and viral infections.

Surface functionalized nanoparticles: A boon to biomedical science

The rapid development of nanomedicine has increased the likelihood that manufactured nanoparticles will one day come into contact with people and the environment. A variety of academic fields, including engineering and the health sciences, have taken a keen interest in the development of nanotechnology. Any significant development in nanomaterial-based applications would depend on the production of functionalized nanoparticles, which are believed to have the potential to be used in fields like pharmaceutical and biomedical sciences. The functionalization of nanoparticles with particular recognition chemical moieties does result in multifunctional nanoparticles with greater efficacy while at the same time minimising adverse effects, according to early clinical studies. This is because of traits like aggressive cellular uptake and focused localization in tumours. To advance this field of inquiry, chemical procedures must be developed that reliably attach chemical moieties to nanoparticles. The structure-function relationship of these functionalized nanoparticles has been extensively studied as a result of the discovery of several chemical processes for the synthesis of functionalized nanoparticles specifically for drug delivery, cancer therapy, diagnostics, tissue engineering, and molecular biology. Because of the growing understanding of how to functionalize nanoparticles and the continued work of innovative scientists to expand this technology, it is anticipated that functionalized nanoparticles will play an important role in the aforementioned domains. As a result, the goal of this study is to familiarise readers with nanoparticles, to explain functionalization techniques that have already been developed, and to examine potential applications for nanoparticles in the biomedical sciences. This review's information is essential for the safe and broad use of functionalized nanoparticles, particularly in the biomedical sector.

Amifostine-Loaded Nanocarrier Traverses the Blood-Brain Barrier and Prevents Radiation-Induced Brain Injury

Radiation-induced brain injury (RIBI) is a severe, irreversible, or even life-threatening cerebral complication of radiotherapy in patients with head and neck tumors, and there is no satisfying prevention and effective treatment available for these patients. Amifostine (AMF) is a well-known free radical scavenger with demonstrated effectiveness in preventing radiation-induced toxicity. However, the limited permeability of AMF across the blood-brain barrier (BBB) when administered intravenously reduces the effectiveness of AMF in preventing RIBI. Herein, we construct a nanoparticle (NP) platform for BBB delivery of AMF. AMF is conjugated with 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine-n-[poly(ethylene glycol)]-hydroxy succinamide [DSPE-PEG-NHS, PEG M 2000], and the product is DSPE-PEG-AMF. Then, the nanoparticles (DAPP NPs) were formed by self-assembly of poly(lactic-co-glycolic acid) (PLGA), DSPE-PEG-AMF, and polysorbate 80 (PS 80). PEG shields the nanoparticles from blood clearance by the reticuloendothelial system and lengthens the drug circulation time. PS 80 is used to encapsulate nanoparticles for medication delivery to the brain. The results of our study showed that DAPP NPs were able to effectively penetrate the blood-brain barrier (BBB) in healthy C57BL/6 mice. Furthermore, in a well-established mouse model of X-knife-induced brain injury, treatment with DAPP NPs (corresponding to 250 mg/kg AMF) was found to significantly reduce the volume of brain necrosis compared to mice treated with AMF (250 mg/kg). Importantly, the use of DAPP NPs was also shown to significantly mitigate the effects of radiation-induced neuronal damage and glial activation. This work presents a convenient brain-targeted AMF delivery system to achieve effective radioprotection for the brain, providing a promising strategy with tremendous clinical translation potential.

Potential of Lipid-Based Nanocarriers against Two Major Barriers to Drug Delivery-Skin and Blood-Brain Barrier

Over the past few years, pharmaceutical and biomedical areas have made the most astounding accomplishments in the field of medicine, diagnostics and drug delivery. Nanotechnology-based tools have played a major role in this. The implementation of this multifaceted nanotechnology concept encourages the advancement of innovative strategies and materials for improving patient compliance. The plausible usage of nanotechnology in drug delivery prompts an extension of lipid-based nanocarriers with a special reference to barriers such as the skin and blood-brain barrier (BBB) that have been discussed in the given manuscript. The limited permeability of these two intriguing biological barriers restricts the penetration of active moieties through the skin and brain, resulting in futile outcomes in several related ailments. Lipid-based nanocarriers provide a possible solution to this problem by facilitating the penetration of drugs across these obstacles, which leads to improvements in their effectiveness. A special emphasis in this review is placed on the composition, mechanism of penetration and recent applications of these carriers. It also includes recent research and the latest findings in the form of patents and clinical trials in this field. The presented data demonstrate the capability of these carriers as potential drug delivery systems across the skin (referred to as topical, dermal and transdermal delivery) as well as to the brain, which can be exploited further for the development of safe and efficacious products.

Proteins and their functionalization for finding therapeutic avenues in cancer: Current status and future prospective

Despite the remarkable advancement in the health care sector, cancer remains the second most fatal disease globally. The existing conventional cancer treatments primarily include chemotherapy, which has been associated with little to severe side effects, and radiotherapy, which is usually expensive. To overcome these problems, target-specific nanocarriers have been explored for delivering chemo drugs. However, recent reports on using a few proteins having anticancer activity and further use of them as drug carriers have generated tremendous attention for furthering the research towards cancer therapy. Biomolecules, especially proteins, have emerged as suitable alternatives in cancer treatment due to multiple favourable properties including biocompatibility, biodegradability, and structural flexibility for easy surface functionalization. Several in vitro and in vivo studies have reported that various proteins derived from animal, plant, and bacterial species, demonstrated strong cytotoxic and antiproliferative properties against malignant cells in native and their different structural conformations. Moreover, surface tunable properties of these proteins help to bind a range of anticancer drugs and target ligands, thus making them efficient delivery agents in cancer therapy. Here, we discuss various proteins obtained from common exogenous sources and how they transform into effective anticancer agents. We also comprehensively discuss the tumor-killing mechanisms of different dietary proteins such as bovine α-lactalbumin, hen egg-white lysozyme, and their conjugates. We also articulate how protein nanostructures can be used as carriers for delivering cancer drugs and theranostics, and strategies to be adopted for improving their in vivo delivery and targeting. We further discuss the FDA-approved protein-based anticancer formulations along with those in different phases of clinical trials.

Enhancement of mitochondrial function using NO releasing nanoparticles; a potential approach for therapy of Alzheimer's disease

Alzheimer's disease (AD) is the most common type of dementia. Increasing evidence is showing the important role of mitochondrial dysfunction in AD. Mitochondria based oxidative stress, decrease in respiratory chain activity and ATP production are all associated with AD, hence indicating that the enhancement of mitochondrial function and biogenesis present a promising therapeutic approach for AD. Nitric oxide (NO) is an initiator of mitochondrial biogenesis. However, its gaseous nature and very short half-life limit the realization of its therapeutic potential. Additionally, its uncontrolled in-vivo distribution results in generalized vasodilation, hypotension among other off-target effects. Diazeniumdiolates (NONOates) are NO donors that release NO in physiological temperature and pH. Their encapsulation within a hydrophobic matrix carrier system could control the release of NO, and at the same time enable its delivery to the brain. In this work, PAPANONOate (PN) a NO donor was encapsulated in small (92 ± 7 nm) poly (lactic-co-glycolic acid) (PLGA) NPs. These NPs did not induce hemolysis upon intravenous administration and were able to accumulate in the brains of lipopolysaccharides (LPS) induced neurodegeneration mouse models. The encapsulation of PN within a hydrophobic PLGA matrix enabled the sustained release of NO from NPs (≈ 3 folds slower relative to free PN) and successfully delivered PN to brain. As a result, PN-NPs but not free PN resulted in an enhancement in memory and cognition in animals with neurodegeneration as determined by the Y-maze test. The enhancement in cognition was a result of increased mitochondria function as indicated by the increased production of ATP and Cytochrome C oxidase enzyme activity.

Strategic nanocarriers to control neurodegenerative disorders: Concept, challenges, and future perspective

Various neurodegenerative diseases (parkinson, huntington, alzheimer, and amyotrophic lateral sclerosis) are becoming serious global health challenges. Despite various treatment options, successful delivery and effective outcomes have been challenged with several physiological-anatomical barriers, formulation related issues, post-administration hurdles, regulatory constraints, physical hurdles, environmental issues, and safety concern. In the present review, we addressed a brief understanding of pathological and normal condition of blood brain barrier (BBB), rational for brain delivery using nanocarriers, major challenges, advantages of nanomedicine, critical aspects of nanomedicine to translate from bed to clinics, and strategic approaches for improved delivery across BBB. The review addressed various mechanistic perspective for delivery of drug loaded nanocarriers across BBB. Moreover, several reports have been published wherein phytomedicine, exosomes, magnetic nanopartilces, functionalized nanocarriers, cationic nanopartilces, and nano-phytomedicine were investigated for remarkable improvement in neurological disorders. These findings are informative for healthcare professionals, researchers, and scientists working in the domains. The successful application and convincing outcomes of nanomedicines were envisaged with clinical trials conducted on various drugs intended to control neurological disorders (NDs). Conclusively, the review addressed comprehensive findings on various aspects of drug loaded nanocarrier delivery across BBB, considerable risks, potential therapeutic benefits, clinical trial based outcomes, and recent advances followed by future perspectives.

Polymeric Nanoparticles for Delivery of Natural Bioactive Agents: Recent Advances and Challenges

In the last few decades, several natural bioactive agents have been widely utilized in the treatment and prevention of many diseases owing to their unique and versatile therapeutic effects, including antioxidant, anti-inflammatory, anticancer, and neuroprotective action. However, their poor aqueous solubility, poor bioavailability, low GIT stability, extensive metabolism as well as short duration of action are the most shortfalls hampering their biomedical/pharmaceutical applications. Different drug delivery platforms have developed in this regard, and a captivating tool of this has been the fabrication of nanocarriers. In particular, polymeric nanoparticles were reported to offer proficient delivery of various natural bioactive agents with good entrapment potential and stability, an efficiently controlled release, improved bioavailability, and fascinating therapeutic efficacy. In addition, surface decoration and polymer functionalization have opened the door to improving the characteristics of polymeric nanoparticles and alleviating the reported toxicity. Herein, a review of the state of knowledge on polymeric nanoparticles loaded with natural bioactive agents is presented. The review focuses on frequently used polymeric materials and their corresponding methods of fabrication, the needs of such systems for natural bioactive agents, polymeric nanoparticles loaded with natural bioactive agents in the literature, and the potential role of polymer functionalization, hybrid systems, and stimuli-responsive systems in overcoming most of the system drawbacks. This exploration may offer a thorough idea of viewing the polymeric nanoparticles as a potential candidate for the delivery of natural bioactive agents as well as the challenges and the combating tools used to overcome any hurdles.

Evaluation of cytotoxicity, reactive oxygen species and nitrous oxide of nanochitosan from shrimp shell

This work aims to synthesize, characterize and evaluate the biological activity of nanochitosan (NQ) prepared from shrimp, showing an innovative character and correlating with sustainable development, in promoting an alternative to the solid waste (shrimp) shell and a biological application of the novel nanomaterial. The NQ synthesis was carried out by the alkaline deacetylation process of chitin obtained of the demineralization, deproteinization and deodorization steps from shrimp shells. NQ was characterized by X-ray Powder Diffraction (XRD), Fourier Transform infrared spectroscopy (FTIR), Scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDS), N₂ porosimetry (BET/BJH methods), zeta potential (ZP) and zero charge point (pH_ZCP). To evaluate the safety profile was carried out the cytotoxicity, DCFHA and NO tests in 293T and HaCat cell lines. Regarding the cell viability, NQ did not show toxicity for the tested cell lines. In the evaluation of the ROS production and NO tests, there was no increase in the levels of free radicals and between the negative control, respectively. Therefore, NQ does not present cytotoxicity in the cell lines tested (10, 30, 100 and 300 μg mL^-1), proposing new perspectives on the use of NQ as a potential nanomaterial for biomedical applications.

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.

Management of Brain Cancer and Neurodegenerative Disorders with Polymer-Based Nanoparticles as a Biocompatible Platform

The blood-brain barrier (BBB) serves as a protective barrier for the central nervous system (CNS) against drugs that enter the bloodstream. The BBB is a key clinical barrier in the treatment of CNS illnesses because it restricts drug entry into the brain. To bypass this barrier and release relevant drugs into the brain matrix, nanotechnology-based delivery systems have been developed. Given the unstable nature of NPs, an appropriate amount of a biocompatible polymer coating on NPs is thought to have a key role in reducing cellular cytotoxicity while also boosting stability. Human serum albumin (HSA), poly (lactic-co-glycolic acid) (PLGA), Polylactide (PLA), poly (alkyl cyanoacrylate) (PACA), gelatin, and chitosan are only a few of the significant polymers mentioned. In this review article, we categorized polymer-coated nanoparticles from basic to complex drug delivery systems and discussed their application as novel drug carriers to the brain.

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

In view of the fact that the blood-brain barrier (BBB) prevents the transport of imaging probes and therapeutic agents to the brain and thus hinders the diagnosis and treatment of brain-related disorders, methods of circumventing this problem (e.g., ultrasound-mediated nanoparticle delivery) have drawn much attention. Among the related techniques, focused ultrasound (FUS) is a favorite means of enhancing drug delivery via transient BBB opening. Photoacoustic brain imaging relies on the conversion of light into heat and the detection of ultrasound signals from contrast agents, offering the benefits of high resolution and large penetration depth. The extensive versatility and adjustable physicochemical properties of nanoparticles make them promising therapeutic agents and imaging probes, allowing for successful brain imaging and treatment through the combined action of ultrasound and nanoparticulate agents. FUS-induced BBB opening enables nanoparticle-based drug delivery systems to efficiently access the brain. Moreover, photoacoustic brain imaging using nanoparticle-based contrast agents effectively visualizes brain morphologies or diseases. Herein, we review the progress in the simultaneous use of nanoparticles and ultrasound in brain research, revealing the potential of ultrasound-mediated nanoparticle delivery for the effective diagnosis and treatment of brain disorders.

Neuro-nanotechnology: diagnostic and therapeutic nano-based strategies in applied neuroscience

Artificial, de-novo manufactured materials (with controlled nano-sized characteristics) have been progressively used by neuroscientists during the last several decades. The introduction of novel implantable bioelectronics interfaces that are better suited to their biological targets is one example of an innovation that has emerged as a result of advanced nanostructures and implantable bioelectronics interfaces, which has increased the potential of prostheses and neural interfaces. The unique physical-chemical properties of nanoparticles have also facilitated the development of novel imaging instruments for advanced laboratory systems, as well as intelligently manufactured scaffolds and microelectrodes and other technologies designed to increase our understanding of neural tissue processes. The incorporation of nanotechnology into physiology and cell biology enables the tailoring of molecular interactions. This involves unique interactions with neurons and glial cells in neuroscience. Technology solutions intended to effectively interact with neuronal cells, improved molecular-based diagnostic techniques, biomaterials and hybridized compounds utilized for neural regeneration, neuroprotection, and targeted delivery of medicines as well as small chemicals across the blood-brain barrier are all purposes of the present article.

Comparative Analysis of the Interaction of Silver Nanoparticles with Hexokinase from Trypanosoma brucei and Humans

Background

Regardless of the efforts to ease cases of human African trypanosomiasis (HAT), an increased number of cases get reported annually. This is because of drug resistant Trypanosoma brucei (Tb), the causative agent of the illness. This has renewed the need for creative methods to find new anti-trypanosomal drugs. The blood stream form (BSF) of the parasite depends exclusively on the glycolytic pathway for energy production while it is in the human host. Interruptions in this pathway efficiently kills the parasite. Trypanosoma brucei hexokinase (TbHK) is the first enzyme in glycolysis, and any effectors or inhibitors of TbHK would have potential as anti-trypanosomal agents.

Methods

TbHK and human glucokinase (hGCK) were over-expressed with a 6 histidine-tag in E. coli BL21(DE3) cells having the pRARE2 plasmid.

Results

TbHK had thermal and pH stability between 30°C and 55°C and 7.5 and 8.5, respectively, while hGCK exhibited thermal and pH stability between 30°C and 40°C and 7.0 and 8.0, respectively. Kinetically, TbHK had a K_m of 39.3 µM, V_max of 0.066 µmol.min^-1.mL^-1, k_cat of 2.05 min^-1 and k_cat/K_m of 0.0526 min^-1.µmol^-1. hGCK exhibited a K_m of 4.5 µM, V_max of 0.032 µnmol.min^-1.mL^-1, k_cat of 11.25 min^-1, and k_cat/K_m of 2.5 min^-1.µmol^-1. Interaction kinetic studies of silver nanoparticles (AgNPs) (0.1 µM) of average size of 6 nm with TbHK and hGCK were conducted. AgNPs selectively inhibited TbHK over hGCK. TbHK showed a non-competitive inhibition with a 50% and 28% decrease in V_max, and k_cat/k_m, respectively. HsGCK showed a 33% increase in affinity, 9% decrease in V_max, and a 50% increase in enzyme efficiency.

Conclusion

The observed pattern of hGCK and AgNPs falls under the uncompetitive inhibition. The observed highly selective inhibitory effects of AgNPs between TbHK and hGCK may be used in development of new anti-trypanosomal drugs.

Protein corona: Friend or foe? Co-opting serum proteins for nanoparticle delivery

For systemically delivered nanoparticles to reach target tissues, they must first circulate long enough to reach the target and extravasate there. A challenge is that the particles end up engaging with serum proteins and undergo immune cell recognition and premature clearance. The serum protein binding, also known as protein corona formation, is difficult to prevent, even with artificial protection via "stealth" coating. Protein corona may be problematic as it can interfere with the interaction of targeting ligands with tissue-specific receptors and abrogate the so-called active targeting process, hence, the efficiency of drug delivery. However, recent studies show that serum protein binding to circulating nanoparticles may be actively exploited to enhance their downstream delivery. This review summarizes known issues of protein corona and traditional strategies to control the corona, such as avoiding or overriding its formation, as well as emerging efforts to enhance drug delivery to target organs via nanoparticles. It concludes with a discussion of prevailing challenges in exploiting protein corona for nanoparticle development.

Dosimetry Effects Due to the Presence of Fe Nanoparticles for Potential Combination of Hyperthermic Cancer Treatment with MRI-Based Image-Guided Radiotherapy

Nanoparticles have proven to be biocompatible and suitable for many biomedical applications. Currently, hyperthermia cancer treatments based on Fe nanoparticle infusion excited by alternating magnetic fields are commonly used. In addition to this, MRI-based image-guided radiotherapy represents, nowadays, one of the most promising accurate radiotherapy modalities. Hence, assessing the feasibility of combining both techniques requires preliminary characterization of the corresponding dosimetry effects. The present work reports on a theoretical and numerical simulation feasibility study aimed at pointing out preliminary dosimetry issues. Spatial dose distributions incorporating magnetic nanoparticles in MRI-based image-guided radiotherapy have been obtained by Monte Carlo simulation approaches accounting for all relevant radiation interaction properties as well as charged particles coupling with strong external magnetic fields, which are representative of typical MRI-LINAC devices. Two main effects have been evidenced: local dose enhancement (up to 60% at local level) within the infused volume, and non-negligible changes in the dose distribution at the interfaces between different tissues, developing to over 70% for low-density anatomical cavities. Moreover, cellular uptakes up to 10% have been modeled by means of considering different Fe nanoparticle concentrations. A theoretical temperature-dependent model for the thermal enhancement ratio (TER) has been used to account for radiosensitization due to hyperthermia. The outcomes demonstrated the reliability of the Monte Carlo approach in accounting for strong magnetic fields and mass distributions from patient-specific anatomy CT scans to assess dose distributions in MRI-based image-guided radiotherapy combined with magnetic nanoparticles, while the hyperthermic radiosensitization provides further and synergic contributions.

Antiparkinsonian Agents in Investigational Polymeric Micro- and Nano-Systems

Parkinson's disease (PD) is a devastating neurodegenerative disease characterized by progressive destruction of dopaminergic tissue in the central nervous system (CNS). To date, there is no cure for the disease, with current pharmacological treatments aimed at controlling the symptoms. Therefore, there is an unmet need for new treatments for PD. In addition to new therapeutic options, there exists the need for improved efficiency of the existing ones, as many agents have difficulties in crossing the blood-brain barrier (BBB) to achieve therapeutic levels in the CNS or exhibit inappropriate pharmacokinetic profiles, thereby limiting their clinical benefits. To overcome these limitations, an interesting approach is the use of drug delivery systems, such as polymeric microparticles (MPs) and nanoparticles (NPs) that allow for the controlled release of the active ingredients targeting to the desired site of action, increasing the bioavailability and efficacy of treatments, as well as reducing the number of administrations and adverse effects. Here we review the polymeric micro- and nano-systems under investigation as potential new therapies for PD.

Nanoparticles in Drug Delivery: From History to Therapeutic Applications

Current research into the role of engineered nanoparticles in drug delivery systems (DDSs) for medical purposes has developed numerous fascinating nanocarriers. This paper reviews the various conventionally used and current used carriage system to deliver drugs. Due to numerous drawbacks of conventional DDSs, nanocarriers have gained immense interest. Nanocarriers like polymeric nanoparticles, mesoporous nanoparticles, nanomaterials, carbon nanotubes, dendrimers, liposomes, metallic nanoparticles, nanomedicine, and engineered nanomaterials are used as carriage systems for targeted delivery at specific sites of affected areas in the body. Nanomedicine has rapidly grown to treat certain diseases like brain cancer, lung cancer, breast cancer, cardiovascular diseases, and many others. These nanomedicines can improve drug bioavailability and drug absorption time, reduce release time, eliminate drug aggregation, and enhance drug solubility in the blood. Nanomedicine has introduced a new era for drug carriage by refining the therapeutic directories of the energetic pharmaceutical elements engineered within nanoparticles. In this context, the vital information on engineered nanoparticles was reviewed and conferred towards the role in drug carriage systems to treat many ailments. All these nanocarriers were tested in vitro and in vivo. In the coming years, nanomedicines can improve human health more effectively by adding more advanced techniques into the drug delivery system.

Polymer nanocarriers for targeted local delivery of agents in treating brain tumors

Glioblastoma (GBM), the deadliest brain cancer, presents a multitude of challenges to the development of new therapies. The standard of care has only changed marginally in the past 17 years, and few new chemotherapies have emerged to supplant or effectively combine with temozolomide. Concurrently, new technologies and techniques are being investigated to overcome the pharmacokinetic challenges associated with brain delivery, such as the blood brain barrier (BBB), tissue penetration, diffusion, and clearance in order to allow for potent agents to successful engage in tumor killing. Alternative delivery modalities such as focused ultrasound and convection enhanced delivery allow for the local disruption of the BBB, and the latter in particular has shown promise in achieving broad distribution of agents in the brain. Furthermore, the development of polymeric nanocarriers to encapsulate a variety of cargo, including small molecules, proteins, and nucleic acids, have allowed for formulations that protect and control the release of said cargo to extend its half-life. The combination of local delivery and nanocarriers presents an exciting opportunity to address the limitations of current chemotherapies for GBM toward the goal of improving safety and efficacy of treatment. However, much work remains to establish standard criteria for selection and implementation of these modalities before they can be widely implemented in the clinic. Ultimately, engineering principles and nanotechnology have opened the door to a new wave of research that may soon advance the stagnant state of GBM treatment development.

Hybrid Membrane-Derived Nanoparticles for Isoliquiritin Enhanced Glioma Therapy

Due to the obstruction and heterogeneity of the blood-brain barrier, the clinical treatment of glioma has been extremely difficult. Isoliquiritigenin (ISL) exhibits antitumor effects, but its low solubility and bioavailability limit its application potential. Herein, we established a nanoscale hybrid membrane-derived system composed of erythrocytes and tumor cells. By encapsulating ISL in hybrid membrane nanoparticles, ISL is expected to be enhanced for the targeting and long-circulation in gliomas therapy. We fused erythrocytes with human glioma cells U251 and extracted the fusion membrane via hypotension, termed as hybrid membrane (HM). HM-camouflaged ISL nanoparticles (ISL@HM NPs) were prepared and featured with FT-IR, SEM, TEM, and DLS particle analysis. As the results concluded, the ISL active pharmaceutical ingredients (APIs) were successfully encapsulated with HM membranes, and the NPs loading efficiency was 38.9 ± 2.99% under maximum entrapment efficiency. By comparing the IC50 of free ISL and NPs, we verified that the solubility and antitumor effect of NPs was markedly enhanced. We also investigated the mechanism of the antitumor effect of ISL@HM NPs, which revealed a marked inhibition of tumor cell proliferation and promotion of senescence and apoptosis of tumor cells of the formulation. In addition, the FSC and WB results examined the effects of different concentrations of ISL@HM NPs on tumor cell disruption and apoptotic protein expression. Finally, it can be concluded that hybridized membrane-derived nanoparticles could prominently increase the solubility of insoluble materials (as ISL), and also enhance its targeting and antitumor effect.

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.

Therapeutic nanotechnologies for Alzheimer's disease: a critical analysis of recent trends and findings

Alzheimer's Disease (AD) is an irreversible neurodegenerative disease for which no disease modifying therapies are presently available. Besides the identification of pathological targets, AD presents numerous clinical and pharmacological challenges such as efficient active delivery to the central nervous system, cell targeting, and long-term dosing. Nanoparticles have been explored to overcome some of these challenges as drug delivery vehicles or drugs themselves. However, early promises have failed to materialize as no nanotechnology-based product has been able to reach the market and very few have moved past preclinical stages. In this review, we perform a critical analysis of the past decade's research on nanomedicine-based therapies for AD at the preclinical and clinical stages. The main obstacles to nanotechnology products and the most promising approaches were also identified, including renewed promise with gene editing, gene modulation, and vaccines.

Supramolecular Hydrogel Based Post-Surgical Implant System for Hydrophobic Drug Delivery Against Glioma Recurrence

Purpose

The brain, protected by the cranium externally and the blood–brain barrier (BBB) internally, poses challenges in chemotherapy of aggressive brain tumors. Maximal tumor resection followed by radiation and chemotherapy is the standard treatment protocol; however, a substantial number of patients suffer from recurrence. Systemic circulation of drugs causes myelodysplasia and other side effects. To address these caveats, we report facile synthesis of a polyester-based supramolecular hydrogel as a brain biocompatible implant for in situ delivery of hydrophobic drugs.

Methods

Polycaprolactone-diol (PCL) was linked to polyethyleneglycol-diacid (PEG) via an ester bond. In silico modeling indicated micelle-based aggregation of PCL-PEG co-polymer to form a supramolecular hydrogel. Brain biocompatibility was checked in Sprague Dawley rat brain cortex with MRI, motor function test, and histology. Model hydrophobic drugs carmustine and curcumin entrapment propelled glioma cells into apoptosis-based death evaluated by in vitro cytotoxicity assays and Western blot. In vivo post-surgical xenograft glioma model was developed in NOD-SCID mice and evaluated for efficacy to restrict aggressive regrowth of tumors.

Results

20% (w/v) PCL-PEG forms a soft hydrogel that can cover the uneven and large surface area of a tumor resection cavity and maintain brain density. The PCL-PEG hydrogel was biocompatible, and well-tolerated upon implantation in rat brain cortex, for a study period of 12 weeks. We report for the first time the combination of carmustine and curcumin entrapped as model hydrophobic drugs, increasing their bioavailability and yielding synergistic apoptotic effect on glioma cells. Further in vivo study indicated PCL-PEG hydrogel with a dual cargo of carmustine and curcumin restricted aggressive regrowth post-resection significantly compared with control and animals with intravenous drug treatment.

Conclusion

PCL-PEG soft gel-based implant is malleable compared with rigid wafers used as implants, thus providing larger surface area contact. This stable, biocompatible, supramolecular gel without external crosslinking can find wide applications by interchanging formulation of various hydrophobic drugs to ensure and increase site-specific delivery, avoiding systemic circulation.

Changes in target ability of nanoparticles due to protein corona composition and disease state

Many studies have shown the influence of protein corona (PC) on the active targeting capability of ligand-modified nanoparticles; however, the influence of clinical status on PC composition and targeting capacity is rarely discussed. In this study, when transferrin-modified PEGylated polystyrene nanoparticles (Tf-PNs) is intravenously injected into mice with non-small cell lung cancer (NSCLC) comorbid with type 2 diabetes mellitus (T2DM), more Tf-PNs accumulated in the tumor tissue than in those of NSCLC model mice. This indicated that PC derived from different states of disease changed the active targeting ability of Tf-PNs. To explain the occurrence of this phenomenon, our analysis of PC from different disease states revealed that Tf (transferrin) modification had no significant effect on the formation of PC, and that the PC from the NSCLC comorbid with T2DM model contained more proteins like fibrin and clusterin. This work demonstrates the impacts of comorbidity, such as with T2DM, on the active targeting capability of ligand-modified nanoparticles, and the results promote the application of nanoparticles for precision medicine.

Glymphatic System and Subsidiary Pathways Drive Nanoparticles Away from the Brain

Although drug delivery systems (DDS) are efficient in brain delivery, they face failure in clinical settings due to their potential toxicity to the central nervous system. Little is known about where the DDS will go after brain delivery, and no specific elimination route that shares a passage with DDS has been verified. Hence, identifying harmless DDS for brain delivery and determining their fate there would strongly contribute to their clinical translation. In this study, we investigated nonreactive gold nanoclusters, which can deliver into the brain, to determine the elimination route of DDS. Subsequently, nanoclusters in the brain were systemically tracked and were found to be critically drained by the glymphatic system from the blood vessel basement membrane to periphery circulations (77.8 ± 23.2% and 43.7 ± 23.4% contribution). Furthermore, the nanoclusters could be actively transported across the blood-brain barrier (BBB) by exosomes (30.5 ± 27.3% and 29.2 ± 7.1% contribution). In addition, microglia promoted glymphatic drainage and passage across the BBB. The simultaneous work of the glymphatic system, BBB, and microglia revealed the fate of gold nanoclusters for brain delivery and provided a basis for further brain-delivery DDS.

Evaluation of Brain Targeting Potential of Zolmitriptan Mucoadhesive Nanoparticles for Intranasal Drug Delivery

BACKGROUND

Hydrophilic drugs are poor applicants of brain targeting via oral route due to the presence of blood-brain barrier that allows only small lipophilic molecules to freely access the brain. Due to unique anatomical connections between the nasal cavity and the brain, intranasal administration can be explored for drug delivery to the brain directly that circumvents blood-brain barrier too.

OBJECTIVES

Zolmitriptan is a widely used antimigraine drug and its brain targeting by nasal route in form of mucoadhesive nanoparticles is more effective in migraine treatment as it provide fast relief and good bioavailability as compared to its oral drug delivery. In the present study zolmitriptan mucoadhesive nanoparticles were prepared to improve the bioavailability and brain targeting for the better management of Migraine attacks.

METHODS

The mucoadhesive polymeric nanoparticles of zolmitriptan were formulated by modified ionic gelation method using thiolated chitosan. The pharmacokinetic parameters were counted in male Wistar rats by intranasal and oral delivery of anti-migraine drug zolmitriptan and compared statistically. The concentration of zolmitriptan in the blood plasma and brain samples was determined by using liquid-liquid extraction method followed by a reversed- phase high performance liquid chromatography (RP-HPLC) analysis. The pharmacodynamic analysis was done in adult male Swiss albino mice by behavioral models, light/dark box model, and acetic acid- induced writhing (abdominal stretching or constriction). These tests were used to reproduce the important associated symptoms of migraine viz. hyperalgesia (nociceptive sensitization) and photophobia for the assessment of the therapeutic potential of intranasal delivery of nanoparticles for anti-migraine activity.

RESULTS

The absolute bioavailability accessed for Zolmitriptan nanoparticles by IN route was found to be very high (193%), suggested that the sufficient amount drug transported by nanoparticles and DTE ratio was calculated 2.8, revealed better nose to brain transport by zolmitriptan nanoparticles as compared to oral delivery in male Wistar rats. A Significant increase in tolerance capacity of animals to bright light and fall in the numbers of stretching in mice suggested that the better management of migraine-associated symptoms by the zolmitriptan nanoparticles.

CONCLUSION

Thus present study confers the significance of nasal drug delivery for brain targeting of zolmitriptan nanoparticles for the treatment of migraine.

Immobilization of phlorotannins on nanochitin: A novel biopreservative for refrigerated sea bass (Lateolabrax japonicus) fillets

A novel biopreservative was developed by immobilizing phlorotannins into nanochitin (NCh). NCh were selected as a host complex to immobilized phlorotannins and the structural properties and antioxidant activity of the NCh-phlorotannins nanocomplex was investigated. The NCh-phlorotannins showed high antioxidant activity, as evidenced by free radical scavenging activity test. Moreover, the effects of NCh-phlorotannins on physical [color, water holding capacity (WHC), and texture], chemical [thiobarbituric acid (TBA) values, total volatile base nitrogen (TVB-N), and pH], microbiological [total viable count], changes of refrigerated sea bass (Lateolabrax japonicus) fillets were also evaluated. Sea bass fillets add with 1.5 g/kg NCh-phlorotannins had lower bacterial growth, pH, TVB-N and TBA as well as better characteristics of texture, color, and WHC than those of the control group during refrigerated storage. The efficiency of NCh-phlorotannins treatment was also better than that of phlorotannins or NCh treatment alone. Therefore, NCh-phlorotannins may be a potential biopreservative to extend the shelf-life of sea bass fillets quality during refrigerated storage.

Nose-to-brain lipid nanocarriers: An active transportation across BBB in migraine management

The present study focused on the development and evaluation of nanotechnology-based carrier systems of solid lipid nanoparticles (SLNs) to enhance the permeation and bioavailability of zolmitriptan across blood-brain-barrier (BBB). SLNs are the emerging field of nanotechnology with numerous applications like cosmetics and pharmaceutical research. Zolmitriptan-loaded SLNs were prepared by high-pressure homogenization method for targeted drug delivery to the brain. The SLNs were found to be round in shape with particle size ranging from 110 to 200nm and zeta potential upto -24.83± 3.03mV which indicates good colloidal stability. The maximum entrapment efficiency of zolmitriptan in SLNs was found to be 84.17± 12.24%. The in-vitro drug release and ex-vivo release studies exhibited 95.85±2.44% and 82.06±2.94% drug release, respectively for 24h. In-vivo studies was performed on male Wistar rats wherein the concentration of zolmitriptan was estimated in cerebrospinal fluid by LC-MS method. The selected formulation incorporated with SLNs showed significant enhancement in pharmacokinetic parameters like AUC (37.05± 2.45ng/mL), C_max (42.08 ± 1.32ng/mL), T_max (30min), and t_1/2 (1.28h). Zolmitriptan-loaded SLNs via intranasal administration offers a novel approach to effectively circumvent first-pass hepatic metabolism than conventional oral route with 4-fold alleviation in permeation and 2-fold improvement in bioavailability. DATA AVAILABILITY: The data used to support the findings of this study are included within the article.

Neurosurgery at the crossroads of immunology and nanotechnology. New reality in the COVID-19 pandemic

Neurosurgery as one of the most technologically demanding medical fields rapidly adapts the newest developments from multiple scientific disciplines for treating brain tumors. Despite half a century of clinical trials, survival for brain primary tumors such as glioblastoma (GBM), the most common primary brain cancer, or rare ones including primary central nervous system lymphoma (PCNSL), is dismal. Cancer therapy and research have currently shifted toward targeted approaches, and personalized therapies. The orchestration of novel and effective blood-brain barrier (BBB) drug delivery approaches, targeting of cancer cells and regulating tumor microenvironment including the immune system are the key themes of this review. As the global pandemic due to SARS-CoV-2 virus continues, neurosurgery and neuro-oncology must wrestle with the issues related to treatment-related immune dysfunction. The selection of chemotherapeutic treatments, even rare cases of hypersensitivity reactions (HSRs) that occur among immunocompromised people, and number of vaccinations they have to get are emerging as a new chapter for modern Nano neurosurgery.

Polysorbate-coated mesoporous silica nanoparticles as an efficient carrier for improved rivastigmine brain delivery

Targeted delivery of neurological therapeutic to the brain has been attracting more and more attention to the treatment of central nervous system (CNS) diseases. Nonetheless, the main obstacle in this road map is the existence of a blood-brain barrier (BBB) which limits the penetration efficiency of most CNS drugs into the brain parenchyma. This present investigation describes a facile synthetic strategy to prepare a highly biocompatible calcium-doped mesoporous silica nanoparticles (MSNs) functionalized by polysorbate-80 (PS) as targeting ligand to deliver rivastigmine (RV) into the brain via crossing the BBB. The developed nanosystem was characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), transmission electron microscopy (TEM), Zeta potential, and N₂-adsorption-desorption analysis. In vitro hemolysis studies were carried out to confirm the biocompatibility of the nanocarriers. Our in vivo studies in an animal model of rats showed that the RV-loaded nanosystem was able to enhance the brain-to-plasma concentration ratio, brain uptake clearance, and plasma elimination half-life of the drug compared to the free one drug following intravenous (IV) administration. The results revealed that functionalization of MSNs by PS is crucial to deliver RV into the brain, suggesting PS-functionalized MSNs could be an effective carrier to deliver RV to the brain while overcoming BBB.

Nanotechnology-based drug delivery for the treatment of CNS disorders

Approximately 6.8 million people die annually because of problems related to the central nervous system (CNS), and out of them, approximately 1 million people are affected by neurodegenerative diseases that include Alzheimer's disease, multiple sclerosis, epilepsy, and Parkinson's disease. CNS problems are a primary concern because of the complexity of the brain. There are various drugs available to treat CNS disorders and overcome problems with toxicity, specificity, and delivery. Barriers like the blood-brain barrier (BBB) are a challenge, as they do not allow therapeutic drugs to cross and reach their target. Researchers have been searching for ways to allow drugs to pass through the BBB and reach the target sites. These problems highlight the need of nanotechnology to alter or manipulate various processes at the cellular level to achieve the desired attributes. Due to their nanosize, nanoparticles are able to pass through the BBB and are an effective alternative to drug administration and other approaches. Nanotechnology has the potential to improve treatment and diagnostic techniques for CNS disorders and facilitate effective drug transfer. With the aid of nanoengineering, drugs could be modified to perform functions like transference across the BBB, altering signaling pathways, targeting specific cells, effective gene transfer, and promoting regeneration and preservation of nerve cells. The involvement of a nanocarrier framework inside the delivery of several neurotherapeutic agents used in the treatment of neurological diseases is reviewed in this study.

Combatting Helicobacter pylori with oral nanomedicines

Helicobacter pylori (H. pylori) infection is considered to be the main cause of most digestive diseases,such as chronic active gastritis, gastroduodenal ulcers, or even gastric cancer. Oral medication is a transformative approach to treat H. pylori-induced infections. However, unlike intravenous administration, orally administrated drugs have to overcome various barriers before reaching the infected sites, which significantly limits the therapeutic efficacy. These challenges may be addressed by emerging nanomedicine that is equipped with nanotechnology approaches to enable efficient and effective targeted delivery of drugs. Herein, in this review, we first discuss the conventional therapy for the eradication of H. pylori. Through the introduction of the critical barriers of oral administration, the benefits of nanomedicine are highlighted. Recently-published examples of nanocarriers for combating H. pylori in terms of design, preparation, and antimicrobial mechanisms are then presented, followed by our perspective on potential future research directions of oral nanomedicines.

Cell Membrane-Coated Mimics: A Methodological Approach for Fabrication, Characterization for Therapeutic Applications, and Challenges for Clinical Translation

Cell membrane-coated (CMC) mimics are micro/nanosystems that combine an isolated cell membrane and a template of choice to mimic the functions of a cell. The design exploits its physicochemical and biological properties for therapeutic applications. The mimics demonstrate excellent biological compatibility, enhanced biointerfacing capabilities, physical, chemical, and biological tunability, ability to retain cellular properties, immune escape, prolonged circulation time, and protect the encapsulated drug from degradation and active targeting. These properties and the ease of adapting them for personalized clinical medicine have generated a significant research interest over the past decade. This review presents a detailed overview of the recent advances in the development of cell membrane-coated (CMC) mimics. The primary focus is to collate and discuss components, fabrication methodologies, and the significance of physiochemical and biological characterization techniques for validating a CMC mimic. We present a critical analysis of the two main components of CMC mimics: the template and the cell membrane and mapped their use in therapeutic scenarios. In addition, we have emphasized on the challenges associated with CMC mimics in their clinical translation. Overall, this review is an up to date toolbox that researchers can benefit from while designing and characterizing CMC mimics.

Nanoparticle-Guided Brain Drug Delivery: Expanding the Therapeutic Approach to Neurodegenerative Diseases

Neurodegenerative diseases (NDs) represent a heterogeneous group of aging-related disorders featured by progressive impairment of motor and/or cognitive functions, often accompanied by psychiatric disorders. NDs are denoted as 'protein misfolding' diseases or proteinopathies, and are classified according to their known genetic mechanisms and/or the main protein involved in disease onset and progression. Alzheimer's disease (AD), Parkinson's disease (PD) and Huntington's disease (HD) are included under this nosographic umbrella, sharing histopathologically salient features, including deposition of insoluble proteins, activation of glial cells, loss of neuronal cells and synaptic connectivity. To date, there are no effective cures or disease-modifying therapies for these NDs. Several compounds have not shown efficacy in clinical trials, since they generally fail to cross the blood-brain barrier (BBB), a tightly packed layer of endothelial cells that greatly limits the brain internalization of endogenous substances. By engineering materials of a size usually within 1-100 nm, nanotechnology offers an alternative approach for promising and innovative therapeutic solutions in NDs. Nanoparticles can cross the BBB and release active molecules at target sites in the brain, minimizing side effects. This review focuses on the state-of-the-art of nanoengineered delivery systems for brain targeting in the treatment of AD, PD and HD.

Targeted Propolis-Loaded Poly (Butyl) Cyanoacrylate Nanoparticles: An Alternative Drug Delivery Tool for the Treatment of Cryptococcal Meningitis

In this study, we describe a nano-carrier system for propolis that is able to cross an in vitro model of the blood-brain barrier (BBB) and effectively reduce the virulence of Cryptococcus neoformans in animal models. Antimicrobial properties of propolis have been widely studied. However, propolis applications are limited by its low water solubility and poor bioavailability. Therefore, we recently formulated novel poly (n-butyl cyanoacrylate) nanoparticles (PBCA-NP) containing propolis. PBCA-NP are biocompatible, biodegradable and have been shown to effectively cross the BBB using apolipoprotein E (ApoE) as a ligand. Prepared nanoparticles were characterized for particle size, zeta potential, propolis entrapment efficiency and in vitro release. Additionally, the PBCA-NP were functionalized with polysorbate 80, which then specifically adsorbs ApoE. Using an in vitro BBB model of human brain microvascular endothelial cells hCMEC/D3, it was shown that fluorescence labelled ApoE-functionalized PBCA-NP were internalized by the cells and translocated across the cell monolayer. Propolis-loaded PBCA-NP had in vitro, antifungal activity against C. neoformans, which causes meningitis. To utilize the invertebrate model, Galleria mellonella larvae were infected with C. neoformans and treated with propolis-loaded PBCA-NP. The larvae exhibited normal behavior in toxicity testing, and treatment with propolis-loaded PBCA-NP increased survival in the C. neoformans-infected larvae group. In addition, following cryptococcal infection and then 7 days of treatment, the tissue fungal burden of mice treated with propolis-loaded PBCA-NP was significantly lower than control groups. Therefore, our ApoE-functionalized propolis-loaded PBCA-NP can be deemed as a potential targeted nanoparticle in the therapeutic treatment of cerebral cryptococcosis.

Metallobiology and therapeutic chelation of biometals (copper, zinc and iron) in Alzheimer's disease: Limitations, and current and future perspectives

BACKGROUND

Alzheimer's disease (AD) is the most prevalent cause of cognitive impairment and dementia worldwide. The pathobiology of the disease has been studied in the form of several hypotheses, ranging from oxidative stress, amyloid-beta (Aβ) aggregation, accumulation of tau forming neurofibrillary tangles (NFT) through metal dysregulation and homeostasis, dysfunction of the cholinergic system, and to inflammatory and autophagic mechanism. However, none of these hypotheses has led to confirmed diagnostics or approved cure for the disease.

OBJECTIVE

This review is aimed as a basic and an encyclopedic short course into metals in AD and discusses the advances in chelation strategies and developments adopted in the treatment of the disease. Since there is accumulating evidence of the role of both biometal dyshomeostasis (iron (Fe), copper (Cu), and zinc (Zn)) and metal-amyloid interactions that lead to the pathogenesis of AD, this review focuses on unraveling therapeutic chelation strategies that have been considered in the treatment of the disease, aiming to sequester free and protein-bound metal ions and reducing cerebral metal burden. Promising compounds possessing chemically modified moieties evolving as multi-target ligands used as anti-AD drug candidates are also covered.

RESULTS AND CONCLUSION

Several multidirectional and multifaceted studies on metal chelation therapeutics show the need for improved synthesis, screening, and analysis of compounds to be able to effectively present chelating anti-AD drugs. Most drug candidates studied have limitations in their physicochemical properties; some enhance redistribution of metal ions, while others indirectly activate signaling pathways in AD. The metal chelation process in vivo still needs to be established and the design of potential anti-AD compounds that bi-functionally sequester metal ions as well as inhibit the Aβ aggregation by competing with the metal ions and reducing metal-induced oxidative damage and neurotoxicity may signal a bright end in chelation-based therapeutics of AD.

The Complexity of the Blood-Brain Barrier and the Concept of Age-Related Brain Targeting: Challenges and Potential of Novel Solid Lipid-Based Formulations

Diseases that affect the Central Nervous System (CNS) are one of the most exciting challenges of recent years, as they are ubiquitous and affect all ages. Although these disorders show different etiologies, all treatments share the same difficulty represented by the Blood-Brain Barrier (BBB). This barrier acts as a protective system of the delicate cerebral microenvironment, isolating it and making extremely arduous delivering drugs to the brain. To overtake the obstacles provided by the BBB it is essential to explore the changes that affect it, to understand how to exploit these findings in the study and design of innovative brain targeted formulations. Interestingly, the concept of age-related targeting could prove to be a winning choice, as it allows to consider the type of treatment according to the different needs and peculiarities depending on the disease and the age of onset. In this review was considered the prospective contribution of lipid-based formulations, namely Solid Lipid Nanoparticles (SLNs) and Nanostructured Lipid Carriers (NLCs), which have been highlighted as able to overcome some limitations of other innovative approaches, thus representing a promising strategy for the non-invasive specific treatment of CNS-related diseases.

Challenges towards Targeted Drug Delivery in Cancer Nanomedicines

Despite cancer nanomedicine celebrates already thirty years since its introduction, together with the achievements and progress in cancer treatment area, it still undergoes serious disadvantages that must be addressed. Since the first observation that macromolecules tend to accumulate in tumor tissue due to fenestrated endothelial of vasculature, considered as the “royal gate” in drug delivery field, more than dozens of nanoformulations have been approved and introduced into the practice for cancer treatment. Lipid, polymeric, and hybrid nanocarriers are biocompatible nano-drug delivery systems (NDDs) having suitable physicochemical properties and modulate payload release in response to specific chemical or physical stimuli. Biopharmaceutical properties of NDDs and their efficacy in animal models and humans can significantly affect their impact and perspective in nanomedicine. One of the future directions could be focusing on personalized cancer treatment, considering the heterogeneity and complexity of each patient tumor tissue and the designing of multifunctional targeted NDDs combining synthetic nanomaterials and biological components, like cellular membranes, circulating proteins, RNAi/DNAi, which enforce the efficacy of NDDs and boost their therapeutic effect.