Brain Drug Research Articles

Regulation of Blood-Brain Barrier Transporters by Transforming Growth Factor-β/Activin Receptor-Like Kinase 1 Signaling: Relevance to the Brain Disposition of 3-Hydroxy-3-Methylglutaryl Coenzyme A Reductase Inhibitors (i.e., Statins).

Our laboratory has shown that activation of transforming growth factor- β (TGF- β )/activin receptor-like kinase 1 (ALK1) signaling can increase protein expression and transport activity of organic anion transporting polypeptide 1a4 (Oatp1a4) at the blood-brain barrier (BBB). These results are relevant to treatment of ischemic stroke because Oatp transport substrates such as 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors (i.e., statins) improve functional neurologic outcomes in patients. Advancement of our work requires determination if TGF- β /ALK1 signaling alters Oatp1a4 functional expression differently across brain regions and if such disparities affect central nervous system (CNS) statin disposition. Therefore, we studied regulation of Oatp1a4 by the TGF- β /ALK1 pathway, in vivo, in rat brain microvessels isolated from cerebral cortex, hippocampus, and cerebellum using the ALK1 agonist bone morphogenetic protein-9 (BMP-9) and the ALK1 inhibitor 4-[6-[4-(1-piperazinyl)phenyl]pyrazolo[1,5-a]pyrimidin-3-yl]quinoline dihydrochloride 193189. We showed that Oatp1a4 protein expression and brain distribution of three currently marketed statin drugs (i.e., atorvastatin, pravastatin, and rosuvastatin) were increased in cortex relative to hippocampus and cerebellum. Additionally, BMP-9 treatment enhanced Oatp-mediated statin transport in cortical tissue but not in hippocampus or cerebellum. Although brain drug delivery is also dependent upon efflux transporters, such as P-glycoprotein and/or Breast Cancer Resistance Protein, our data showed that administration of BMP-9 did not alter the relative contribution of these transporters to CNS disposition of statins. Overall, this study provides evidence for differential regulation of Oatp1a4 by TGF- β /ALK1 signaling across brain regions, knowledge that is critical for development of therapeutic strategies to target Oatps at the BBB for CNS drug delivery. SIGNIFICANCE STATEMENT: Organic anion transporting polypeptides (Oatps) represent transporter targets for brain drug delivery. We have shown that Oatp1a4 statin uptake is higher in cortex versus hippocampus and cerebellum. Additionally, we report that the transforming growth factor- β /activin receptor-like kinase 1 agonist bone morphogenetic protein-9 increases Oatp1a4 functional expression, but not efflux transporters P-glycoprotein and Breast Cancer Resistance Protein, in cortical brain microvessels. Overall, this study provides critical data that will advance treatment for neurological diseases where drug development has been challenging.

Identification of lamprey variable lymphocyte receptors that target the brain vasculature

The blood–brain barrier (BBB) represents a significant bottleneck for the delivery of therapeutics to the central nervous system. In recent years, the promise of coopting BBB receptor-mediated transport systems for brain drug delivery has increased in large part due to the discovery and engineering of BBB-targeting antibodies. Here we describe an innovative screening platform for identification of new BBB targeting molecules from a class of lamprey antigen recognition proteins known as variable lymphocyte receptors (VLRs). Lamprey were immunized with murine brain microvessel plasma membranes, and the resultant repertoire cloned into the yeast surface display system. The library was screened via a unique workflow that identified 16 VLR clones that target extracellular epitopes of in vivo-relevant BBB membrane proteins. Of these, three lead VLR candidates, VLR-Fc-11, VLR-Fc-30, and VLR-Fc-46 selectively target the brain vasculature and traffic within brain microvascular endothelial cells after intravenous administration in mice, with VLR-Fc-30 being confirmed as trafficking into the brain parenchyma. Epitope characterization indicates that the VLRs, in part, recognize sialylated glycostructures. These promising new targeting molecules have the potential for brain targeting and drug delivery with improved brain vascular specificity.

Copper bis(thiosemicarbazone) complexes modulate P-glycoprotein expression and function in human brain microvascular endothelial cells.

P‐glycoprotein (P‐gp) is an efflux transporter at the blood–brain barrier (BBB) that hinders brain access of substrate drugs and clears endogenous molecules such as amyloid beta (Aβ) from the brain. As biometals such as copper (Cu) modulate many neuronal signalling pathways linked to P‐gp regulation, it was hypothesised that the bis(thiosemicarbazone) (BTSC) Cu‐releasing complex, copper II glyoxal bis(4‐methyl‐3‐thiosemicarbazone) (CuII[GTSM]), would enhance P‐gp expression and function at the BBB, while copper II diacetyl bis(4‐methyl‐3‐thiosemicarbazone) (CuII[ATSM]), which only releases Cu under hypoxic conditions, would not modulate P‐gp expression. Following treatment with 25–250 nM CuII(BTSC)s for 8–48 h, expression of P‐gp mRNA and protein in human brain endothelial (hCMEC/D3) cells was assessed by RT‐qPCR and Western blot, respectively. P‐gp function was assessed by measuring accumulation of the fluorescent P‐gp substrate, rhodamine 123 and intracellular Cu levels were quantified by inductively coupled plasma mass spectrometry. Interestingly, CuII(ATSM) significantly enhanced P‐gp expression and function 2‐fold and 1.3‐fold, respectively, whereas CuII(GTSM) reduced P‐gp expression 0.5‐fold and function by 200%. As both compounds increased intracellular Cu levels, the effect of different BTSC backbones, independent of Cu, on P‐gp expression was assessed. However, only the Cu‐ATSM complex enhanced P‐gp expression and this was mediated partly through activation (1.4‐fold) of the extracellular signal‐regulated kinase 1 and 2, an outcome that was significantly attenuated in the presence of an inhibitor of the mitogen‐activated protein kinase regulatory pathway. Our findings suggest that CuII(ATSM) and CuII(GTSM) have the potential to modulate the expression and function of P‐gp at the BBB to impact brain drug delivery and clearance of Aβ.

Relational graph convolutional networks for predicting blood-brain barrier penetration of drug molecules.

Evaluating the blood-brain barrier (BBB) permeability of drug molecules is a critical step in brain drug development. Traditional methods for the evaluation require complicated in vitro or in vivo testing. Alternatively, in silico predictions based on machine learning have proved to be a cost-efficient way to complement the in vitro and in vivo methods. However, the performance of the established models has been limited by their incapability of dealing with the interactions between drugs and proteins, which play an important role in the mechanism behind the BBB penetrating behaviors. To address this limitation, we employed the relational graph convolutional network (RGCN) to handle the drug-protein interactions as well as the properties of each individual drug. The RGCN model achieved an overall accuracy of 0.872, an area under the receiver operating characteristic (AUROC) of 0.919 and an area under the precision-recall curve (AUPRC) of 0.838 for the testing dataset with the drug-protein interactions and the Mordred descriptors as the input. Introducing drug-drug similarity to connect structurally similar drugs in the data graph further improved the testing results, giving an overall accuracy of 0.876, an AUROC of 0.926 and an AUPRC of 0.865. In particular, the RGCN model was found to greatly outperform the LightGBM base model when evaluated with the drugs whose BBB penetration was dependent on drug-protein interactions. Our model is expected to provide high-confidence predictions of BBB permeability for drug prioritization in the experimental screening of BBB-penetrating drugs. The data and the codes are freely available at https://github.com/dingyan20/BBB-Penetration-Prediction. Supplementary data are available at Bioinformatics online.

Molecular Imaging of Dopamine Partial Agonists in Humans: Implications for Clinical Practice.

Positron emission tomography (PET) has been used since the late 1980s for the assessment of relationships between occupancy of D2/3 receptors by antipsychotic drugs in the human brain and the clinical effects and side effects of these compounds in patients. It is now well established for most D2/3 antagonists, both of the first and the second generation, that the ideal occupancy of their target receptors is between approximately 65 and 80%. If the occupancy is below 65%, the probability of treatment response is reduced, if the occupancy is higher than 80%, the risk for extrapyramidal side-effects increases substantially. However, partial agonist antipsychotics behave different from these rules. It has been shown for all three available drugs of this class (aripiprazole, brexpiprazole, cariprazine) that, due to their special pharmacology, a very high target engagement (>90%) not only is not harmful but represents a prerequisite for antipsychotic efficacy. The available PET studies for these drugs are reviewed in this work. It is demonstrated that optimal plasma levels for partial agonist antipsychotics can be derived from these studies, which can guide individual treatment in routine patient care.

LIPID-POLYMER HYBRID NANOCARRIERS AS A NOVEL DRUG DELIVERY PLATFORM

The main aim of my review to discuss the most prominent nanocarrier, “Lipid-Polymer Hybrid Nanoparticle” (LPHNPs) that overcomes the limitation of lipid and polymeric nanoparticles. That consists of polymeric core and lipid outer layer. The polymeric core encapsulates both hydrophilic and hydrophobic drugs and lipid shell provides a coat that gives a barrier to prevent drug leakage and easily penetrate into the skin. The LPHNPs has significant application in drug delivery, drug targeting, cancer treatment, brain drug delivery, multiple drug delivery, delivery of diagnostic imaging agent and Small interfering Ribonucleic acid (siRNA). This session is based on literature information in which LPHNPs were prepared by Two-step and Single-step method. Most of the researcher use the Single-step method by emulsification solvent evaporation and Nanoprecipitation method that are easy to prepare LPHNPs. The Polylactic Glycolic acid (PLGA), Poly € caprolactone, Chitosan, Alginate, Dextron, Sodium Alginate, etc used as polymeric core and Stearic Acid, Palmitic Acid, Cetyl Alcohol, Behenol Alcohol, etc used as lipid core. All results were analyzed by us according to the literature and authors’ expertise. The drug release depends on diffusion processes, followed by erosion, then swelling of the matrix. The lipid shell provides a biocompatible shield that acts as the phospholipid bilayer of skin and easily penetrates into the skin. That also capable to deliver the multidrug and diagnostic imaging agent for the treatment of cancer. The Lipid-Polymer Hybrid Nanoparticles are the most prominent nanocarrier for drug delivery. That is capable to deliver both Hydrophilic and Lipophilic drugs and show high bioavailability.

Bubble-vessel interactions: From physics to applications in brain disease theranostics

Focused ultrasound combined with microbubbles (FUS + MB) provides a noninvasive and spatially targeted approach for inducing blood-brain barrier (BBB) disruption. Revealing the interactions among ultrasound, bubbles, and blood vessels is fundamental toward understanding this technique's physical mechanism. These interactions in the brain induce various bioeffects, including BBB disruption. FUS + MB-induced BBB disruption enables two-way trafficking between the brain and the bloodstream. While circulating agents can enter the brain through FUS-mediated BBB disruption for the treatment of brain diseases, brain disease-derived biomarkers (e.g., DNA, RNA, and protein) can also be released into the blood circulation to improve the sensitivity of blood-based liquid biopsy. The application of FUS + MB in brain drug delivery has been translated into the clinic with more than 20 clinical trials currently ongoing. The application of FUS + MB for blood-based liquid biopsy, called sonobiopsy, has been demonstrated feasible for the diagnosis of brain cancer. This talk will cover topics ranging from the fundamental physics of bubble-vessel interactions to their applications in the diagnosis and treatment of brain diseases.

Current Chemical, Biological, and Physiological Views in the Development of Successful Brain-Targeted Pharmaceutics.

One of the greatest challenges with successful pharmaceutical treatments of central nervous system (CNS) diseases is the delivery of drugs into their target sites with appropriate concentrations. For example, the physically tight blood-brain barrier (BBB) effectively blocks compounds from penetrating into the brain, also by the action of metabolizing enzymes and efflux transport mechanisms. However, many endogenous compounds, including both smaller compounds and macromolecules, like amino acids, sugars, vitamins, nucleosides, hormones, steroids, and electrolytes, have their peculiar internalization routes across the BBB. These delivery mechanisms, namely carrier-mediated transport and receptor-mediated transcytosis have been utilized to some extent in brain-targeted drug development. The incomplete knowledge of the BBB and the smaller than a desirable number of chemical tools have hindered the development of successful brain-targeted pharmaceutics. This review discusses the recent advancements achieved in the field from the point of medicinal chemistry view and discusses how brain drug delivery can be improved in the future.

Development of thiolated polyethylene glycol-poly (lactic-co-glycolic acid) co-polymeric nanoparticles for intranasal delivery of quetiapine: in vitro–ex vivo characterization

This study aims to develop quetiapine (QTP)-loaded β-cyclodextrin (β-CD) based co-polymeric thiolated polyethylene glycol-poly(lactic-co-glycolic acid) (t-PEG-PLGA) nanoparticles (QTP@β-CD-t-PEG-PLGA) by transesterification process. As a result, the ex-vivo bioadhesion study shows good bioadhesion because of the thiolation of PEG (t-PEG), which can interrelate through mucin and expand the retention time. In-vitro release study demonstrates the QTP release to 20 h (∼98.76%). Herein, sulfhydryl ligands can form disulfide bonds with cysteine-rich mucus areas that increased the viscosity of mucin and accordingly drug retention. Hence, it can be significant accomplishment for nose to brain drug targeting in psychotic disorder management.

Systemic hypertonic saline enhances glymphatic spinal cord delivery of lumbar intrathecal morphine

The blood-brain barrier significantly limits effective drug delivery to central nervous system (CNS) targets. The recently characterized glymphatic system offers a perivascular highway for intrathecally (i.t.) administered drugs to reach deep brain structures. Although periarterial cerebrospinal fluid (CSF) influx and concomitant brain drug delivery can be enhanced by pharmacological or hyperosmotic interventions, their effects on drug delivery to the spinal cord, an important target for many drugs, have not been addressed. Hence, we studied in rats whether enhancement of periarterial flow by systemic hypertonic solution might be utilized to enhance spinal delivery and efficacy of i.t. morphine. We also studied whether the hyperosmolar intervention affects brain or cerebrospinal fluid drug concentrations after systemic administration. Periarterial CSF influx was enhanced by intraperitoneal injection of hypertonic saline (HTS, 5.8%, 20 ml/kg, 40 mOsm/kg). The antinociceptive effects of morphine were characterized, using tail flick, hot plate and paw pressure tests. Drug concentrations in serum, tissue and microdialysis samples were determined by liquid chromatography-tandem mass spectrometry. Compared with isotonic solution, HTS increased concentrations of spinal i.t. administered morphine by 240% at the administration level (T13–L1) at 60 min and increased the antinociceptive effect of morphine in tail flick, hot plate, and paw pressure tests. HTS also independently increased hot plate and paw pressure latencies but had no effect in the tail flick test. HTS transiently increased the penetration of intravenous morphine into the lateral ventricle, but not into the hippocampus. In conclusion, acute systemic hyperosmolality is a promising intervention for enhanced spinal delivery of i.t. administered morphine. The relevance of this intervention should be expanded to other i.t. drugs and brought to clinical trials.

In Vitro-In Vivo Correlation of Blood-Brain Barrier Permeability of Drugs: A Feasibility Study Towards Development of Prediction Methods for Brain Drug Concentration in Humans.

In vitro human blood-brain barrier (BBB) models in combination with central nervous system-physiologically based pharmacokinetic (CNS-PBPK) modeling, hereafter referred to as the "BBB/PBPK" method, are expected to contribute to prediction of brain drug concentration profiles in humans. As part of our ongoing effort to develop a BBB/PBPK method, we tried to clarify the relationship of in vivo BBB permeability data to those in vitro obtained from a human immortalized cell-based tri-culture BBB model (hiBBB), which we have recently created. The hiBBB models were developed and functionally characterized as previously described. The in vitro BBB permeabilities (Pe, × 10-6cm/s) of seventeen compounds were determined by permeability assays, and in vivo BBB permeabilities (QECF) for eight drugs were estimated by CNS-PBPK modeling. The correlation of the Pe values with the QECF values was analyzed by linear regression analysis. The hiBBB models showed intercellular barrier properties and several BBB transporter functions, which were enough to provide a wide dynamic range of Pe values from 5.7 ± 0.7 (rhodamine 123) to 2580.4 ± 781.9 (rivastigmine). Furthermore, the in vitro Pe values of the eight drugs showed a good correlation (R2 = 0.96) with their in vivo QECF values estimated from human clinical data. We show that in vitro human BBB models provide clinically relevant BBB permeability that can be used as input for CNS-PBPK modeling. Therefore, our findings will encourage the development of a BBB/PBPK method as a promising approach for predicting brain drug concentration profiles in humans.

Modelling of mass transport and distribution of aptamer in blood-brain barrier for tumour therapy and cancer treatment

The blood-brain barrier (BBB) is a strong barrier against the entrance of drugs, which has made brain cancer treatment a major challenge. We have previously shown that targeting transferrin receptors using aptamers increased brain drug delivery. To get a better understanding of this phenomenon, in the present article, a mathematical model based on the finite element method was developed accounting for the fluid flow and mass transport of the aptamer molecule inside an 8 µm capillary vessel across a 14 µm blood-brain barrier domain. The fluid flow and mass transport equations were coupled to calculate the blood velocity and aptamer concentration profiles across the BBB. It was identified that the thickness of the astrocyte and endothelial cell layers are key parameters affecting the concentration of the aptamer delivered to the last neuron dendrites in the BBB. The predicted efficacy of the drug delivery (Capt/Cin) of 10.9% to 13.8% was calculated at a porosity of 0.5 to 0.9, respectively, at a blood velocity of 0.38 mm/s, which was independent of the inlet concentration of the aptamer. This low efficacy was attributed to the mass transfer resistance across endothelial cells, astrocyte and pericyte layers, which decreased the concentration by 6.7%. It was also identified that the main mechanism of drug delivery is switched from convective mass transport in the capillary layer (with Peclet number > 50) to mixed convection mass transport (1 < Peclet number < 5) in the porous layers and to diffusion only once aptamer reached the brain parenchyma (Peclet number < 1).

Strategies to Improve Drug Strength in Nasal Preparations for Brain Delivery of Low Aqueous Solubility Drugs.

Intranasal administration is a promising route for brain drug delivery. However, it can be difficult to formulate drugs that have low water solubility into high strength intranasal solutions. Hence, the purpose of this work was to review the strategies that have been used to increase drug strength in intranasal liquid formulations. Three main groups of strategies are: the use of solubilizers (change in pH, complexation and the use cosolvents/surfactants); incorporation of the drugs into a carrier nanosystem; modifications of the molecules themselves (use of salts or hydrophilic prodrugs). The use of high amounts of cosolvents and/or surfactants and pH decrease below 4 usually lead to local adverse effects, such as nasal and upper respiratory tract irritation. Cyclodextrins and (many) different carrier nanosystems, on the other hand, could be safer for intranasal administration at reasonably high concentrations, depending on selected excipients and their dose. While added attributes such as enhanced permeation, sustained delivery, or increased direct brain transport could be achieved, a great effort of optimization will be required. On the other hand, hydrophilic prodrugs, whether co-administered with a converting enzyme or not, can be used at very high concentrations, and have resulted in a fast prodrug to parent drug conversion and led to high brain drug levels. Nevertheless, the choice of which strategy to use will always depend on the characteristics of the drug and must be a case-by-case approach.

Obsessive Compulsive Tic Disorder: appropriate diagnosis and treatment as key elements to improve health and rationalize use of resources

Background: Obsessive Compulsive Tic Disorder (OCTD) has been described recently as an early onset and highly disabling endophenotype of Tic Disorder and Obsessive Compulsive Disorder. OCTD has a relevant but largely unknown clinical, social and economic burden for patients and their families. Our paper aimed to explore relevant aspects of the burden of OCTD. Methods: we conducted a literature review and a pilot study using retrospective demographic, clinical and economic data of patients with OCTD accessing the Galeazzi Hospital in Milan. Results: the literature review shows the absence of information on OCTD. From the pilot study we analysed data of 30 patients (80.0% male, 36.7% aged from 7 to 13 years, 63.3% aged from 15 to 48 years), 83.0% declared that obsessions and/or compulsions were the most important factors determining their social impairment. Adult patients refractory to drug treatment underwent Deep Brain Stimulation plus drugs. The mean clinical scores at the time of diagnosis indicated a severe condition for both tics and obsessive compulsive components. The mean time elapsed from symptoms onset to diagnosis of OCTD was 5.6 years, reaching up to 11 years in one case. Before reaching the correct diagnosis, different specialists visited the patients several times, 93.3% underwent diagnostic examinations and 86.7% took 2 or 3 different drugs. Ten patients were hospitalised and 8 had received psychotherapy. Discussion: Albeit preliminary, these results show that attention is mandatory for establishing correct diagnosis and treatment guidelines to improve health and rationally spend resources for OCTD.

Linking drug and food addiction via compulsive appetite.

'Food addiction' is the subject of intense public and research interest. However, this nosology based on neurobehavioural similarities among obese individuals, patients with eating disorders and those with substance use disorders (drug addiction) remains controversial. We thus sought to determine which aspects of disordered eating are causally linked to preclinical models of drug addiction. We hypothesized that extensive drug histories, known to cause addiction-like brain changes and drug motivation in rats, would also cause addiction-like food motivation. Rats underwent extensive cocaine, alcohol, caffeine or obesogenic diet histories and were subsequently tested for punishment-resistant food self-administration or 'compulsive appetite', as a measure of addiction-like food motivation. Extensive cocaine and alcohol (but not caffeine) histories caused compulsive appetite that persisted long after the last drug exposure. Extensive obesogenic diet histories also caused compulsive appetite, although neither cocaine nor alcohol histories caused excess calorie intake and bodyweight during abstinence. Hence, compulsive appetite and obesity appear to be dissociable, with the former sharing common mechanisms with preclinical drug addiction models. Compulsive appetite, as seen in subsets of obese individuals and patients with binge-eating disorder and bulimia nervosa (eating disorders that do not necessarily result in obesity), appears to epitomize 'food addiction'. Because different drug and obesogenic diet histories caused compulsive appetite, overlapping dysregulations in the reward circuits, which control drug and food motivation independently of energy homeostasis, may offer common therapeutic targets for treating addictive behaviours across drug addiction, eating disorders and obesity.

Pharmacoproteomics of Brain Barrier Transporters and Substrate Design for the Brain Targeted Drug Delivery

One of the major reasons why central nervous system (CNS)-drug development has been challenging in the past, is the barriers that prevent substances entering from the blood circulation into the brain. These barriers include the blood-brain barrier (BBB), blood-spinal cord barrier (BSCB), blood-cerebrospinal fluid barrier (BCSFB), and blood-arachnoid barrier (BAB), and they differ from each other in their transporter protein expression and function as well as among the species. The quantitative expression profiles of the transporters in the CNS-barriers have been recently revealed, and in this review, it is described how they affect the pharmacokinetics of compounds and how these expression differences can be taken into account in the prediction of brain drug disposition in humans, an approach called pharmacoproteomics. In recent years, also structural biology and computational resources have progressed remarkably, enabling a detailed understanding of the dynamic processes of transporters. Molecular dynamics simulations (MDS) are currently used commonly to reveal the conformational changes of the transporters and to find the interactions between the substrates and the protein during the binding, translocation in the transporter cavity, and release of the substrate on the other side of the membrane. The computational advancements have also aided in the rational design of transporter-utilizing compounds, including prodrugs that can be actively transported without losing potency towards the pharmacological target. In this review, the state-of-art of these approaches will be also discussed to give insights into the transporter-mediated drug delivery to the CNS.

Parkinson's Disease - What is New?

The prevalence of Parkinson's disease (PD) will double by 2030. PD is no longer regarded as a single disease entity. Monogenetic forms may appear clinically identical to sporadic PD. The corona pandemic has caused a deterioration in a great proportion of patients due to concerns of accessing medical care. During this time, teleconsultations emerged as a helpful service for many PD patients as they can reliably administer parts of the neurological examination remotely. New studies address the ongoing controversy about whether the use of levodopa should be delayed. The conclusion is that physicians should not be afraid of using levodopa to treat patients early in the course of PD. Furthermore, the role of dopamine agonists is changing. Besides their known high rates of edema, somnolence and hallucinations dopamine agonists are associated with the development of impulse control disorders in approx. half of the treated patients. During the last 10 years, only two new substances (safinamide, opicapone) have come onto the market in Germany, both with the indication as add on therapy to levodopa in patients with fluctuations. The use of deep brain stimulation and drug pumps in patients with levodopa effect fluctuations is growing, because at this point in the course of the disease, patients also accept invasive therapies that can prolong and optimize independence. Patients who need levodopa more than 5 times a day and who have severe, disturbing OFF phases (> 2 hours a day) despite optimal non-levodopa-based treatment can consider these options. PD stage and symptom-focused, guideline-based physiotherapy has a positive effect on the course of the disease, everyday performance and quality of life and reduces the risk of falling. Multidisciplinary networks are proving effective in reducing falls and hospital admissions.

Targeted delivery of a STING agonist to brain tumors using bioengineered protein nanoparticles for enhanced immunotherapy

Immunotherapy is emerging as a powerful tool for combating many human diseases. However, the application of this life-saving treatment in serious brain diseases, including glioma, is greatly restricted. The major obstacle is the lack of effective technologies for transporting therapeutic agents across the blood-brain barrier (BBB) and achieving targeted delivery to specific cells once across the BBB. Ferritin, an iron storage protein, traverses the BBB via receptor-mediated transcytosis by binding to transferrin receptor 1 (TfR1) overexpressed on BBB endothelial cells. Here, we developed bioengineered ferritin nanoparticles as drug delivery carriers that enable the targeted delivery of a small-molecule immunomodulator to achieve enhanced immunotherapeutic efficacy in an orthotopic glioma-bearing mouse model. We fused different glioma-targeting moieties on self-assembled ferritin nanoparticles via genetic engineering, and RGE fusion protein nanoparticles (RGE-HFn NPs) were identified as the best candidate. Furthermore, RGE-HFn NPs encapsulating a stimulator of interferon genes (STING) agonist (SR717@RGE-HFn NPs) maintained stable self-assembled structure and targeting properties even after traversing the BBB. In the glioma-bearing mouse model, SR717@RGE-HFn NPs elicited a potent local innate immune response in the tumor microenvironment, resulting in significant tumor growth inhibition and prolonged survival. Overall, this biomimetic brain delivery platform offers new opportunities to overcome the BBB and provides a promising approach for brain drug delivery and immunotherapy in patients with glioma.

Preparation, characterization, and biodistribution of glutathione PEGylated nanoliposomal doxorubicin for brain drug delivery with a post-insertion approach.

Objective(s):Brain cancer treatments have mainly failed due to their inability to cross the blood-brain barrier. Several studies have confirmed the presence of glutathione (GSH) receptors on BBB’s surface, as a result, products like 2B3-101, which contain over 5% pre-inserted GSH PEGylated liposomal doxorubicin, are being tested in clinical trials. Here we conducted the PEGylated nanoliposomal doxorubicin particles that are covalently attached to the glutathione using the post-insertion technique. Compared with the pre-insertion approach, the post-insertion method is notably simpler, faster, and more cost-effective, making it ideal for large-scale pharmaceutical manufacturing. Materials and Methods:The ligands of the DSPE PEG(2000) Maleimide-GSH were introduced in the amounts of 25, 50, 100, 200, and 400 on the available Caelyx. Following physicochemical evaluations, animal experiments such as biodistribution, fluorescence microscopy, and pharmacokinetics were done. Results:In comparison with Caelyx, the 200L and 400L treatment arms were the most promising formulations. We showed that nanocarriers containing 40 times fewer GSH micelles than 2B3-101 significantly increased blood-brain barrier penetrance. Due to the expressed GSH receptors on tissues as an endogenous antioxidant, doxorubicin will likely concentrate in the liver, spleen, heart, and lung in comparison with Caelyx, according to other tissue analyses. Conclusion:The post-insertion technique was found a successful approach with more pharmaceutical aspects for large-scale production. Moreover, further investigations are highly recommended to determine the efficacy of 5% post-inserted GSH targeted nanoliposomes versus 2B3-101 as a similar formulation with a different preparation method.

GB20 Pharmacopuncture As a Potential Method for Brain Drug Delivery via the Perivascular Spaces.

The development of new methods of drug brain delivery is a crucial step for the effective therapy of the brain diseases. Pharma- and acupuncture are the forms of alternative therapy of the brain pathology, including an increase in the permeability of blood-brain barrier. However, the mechanisms of pharma- and acupuncture-mediated effects on the brain physiology remain not fully understood. This pilot study on healthy mice clearly demonstrates the Evans Blue spreading in the mouse head and in the brain via the perivascular spaces (PVSs) of the trigeminal structure and the cribriform plate after the dye injection into the Feng Chi point (Galbladder 20, GB20). These results suggest that pharmacopuncture at GB20 can be a perspective method for brain drug delivery via PVSs.