Nanosystems, Drug Molecule Functionalization and Intranasal Delivery: An Update on the Most Promising Strategies for Increasing the Therapeutic Efficacy of Antidepressant and Anxiolytic Drugs

Identification of preventive biomarkers associated with circadian rhythms in traumatic brain injury-mediated depression: Expression of SERPINE1 protein and bioinformatics analysis

Traumatic brain injury (TBI) represents the leading cause of trauma-related mortality, with depression being the most common psychiatric condition following TBI. Although disruptions in circadian rhythms and clock genes have been linked to both conditions, their precise regulatory mechanisms remain unclear. Identifying circadian rhythm-related genes is critical for the prevention and diagnosis of TBI and depression. This study employs Mendelian Randomization (MR) analysis to establish a positive correlation between TBI and depression. Using Weighted Gene Co-expression Network Analysis (WGCNA) on Gene Expression Omnibus (GEO) datasets derived from TBI and depression tissue samples, we identified 99 shared genes functionally linked to circadian rhythms. Furthermore, machine learning algorithms and Receiver Operating Characteristic (ROC) curve analysis identified SERPINE1 as a key diagnostic biomarker for both TBI and depression. In vivo and in vitro experiments further demonstrated that TBI often triggers the development of depression. Suppressing SERPINE1 expression reduced Claudin-1 and BDNF protein levels, alleviating TBI and depressive symptoms. Our findings indicate that SERPINE1 overexpression, which is positively correlated with neutrophil levels, may increase the risk of depression following TBI by disrupting circadian rhythms. This positions SERPINE1 as a critical predictive and diagnostic biomarker for TBI-mediated depression.

β-Cyclodextrin-functionalized nanocarriers for bromocriptine: development, evaluation and histopathological studies

Bromocriptine (BCM), a dopaminergic agonist used in Parkinson's disease treatment, has poor oral bioavailability due to extensive first-pass metabolism and limited gastrointestinal absorption. This study aimed to develop a β-cyclodextrin-functionalized bromocriptine nanoemulsion (oil-in-water) to enhance drug solubility, stability, and bioavailability while facilitating direct brain delivery via the intranasal route. The formulation was designed to overcome systemic metabolic barriers, improve drug permeation across the blood-brain barrier, and ensure sustained therapeutic effects with minimal systemic side effects. Nano-emulsions were prepared using high-shear homogenization. Characterization was performed using scanning electron microscopy (SEM) for morphological analysis. Globule size and zeta potential were measured using Malvern Zetasizer. Fourier Transform Infrared Spectroscopy (FTIR) was used for structural analysis, while X-ray diffraction (XRD) assessed crystallinity. Differential Scanning Calorimetry (DSC) was conducted for thermal analysis. Drug content and in-vitro drug release were evaluated using UV-visible spectroscopy. Stability studies were performed using centrifugation and freeze-thaw methods. Docking studies and Histopathological evaluation were also performed of the prepared formulations. Morphological studies revealed nano-sized globular particles with a mean diameter of 117.2 nm and a low polydispersity index (PDI 0.810), indicating uniformity. The nanoemulsion exhibited a zeta potential of -10.5 mV, ensuring colloidal stability. The encapsulation efficiency (EE%) of the optimized formulation (F4) was 95.36(% w/w,) with a drug load of approximately 9.5(% w/w). In-vitro drug release reached 85.65%, with permeation release of 78.44% and 70.13% ex-vivo. The formulation remained stable under freeze-thaw and centrifugation conditions. Cell toxicity assessments demonstrated excellent biocompatibility, with no significant cytotoxic effects observed in histopathological evaluations. This nanoemulsion presents a promising alternative to oral bromocriptine for Parkinson's treatment.

Development of a predictive model for pediatric intranasal drug delivery with nasal sprays: Leveraging intersubject variability in anatomical dimensions, administration-related parameters, and airway patency

In this study, we examined the correlation between anatomical dimensions, spray administration parameters, pressure drop across 40 pediatric nasal cavities, and in vitro posterior drug delivery (PDD) using Nasacort ALLERGY 24HR and FLONASE SENSIMIST nasal suspensions sprays, with different nozzle and actuation designs. The importance of each parameter and their interaction in the outcome (PDD) was evaluated. To do so, initially we measured anatomical and administration-related parameters, and the pressure drop of each cavity. Afterwards, a stepwise regression method was used to find a combination of parameters that can effectively predict the outcome. Two strong correlations, r2 = 0.802 and 0.895, were found between a combination of three explored parameters and the PDD of Nasacort and Flonase Sensimist, respectively. While, based on the p-values, the insertion depth was found to be the most influential parameter for determining the PDD with Nasacort, and the administration coronal angle was found to be the most important one for Flonase Sensimist, anatomical parameters, or an interaction between anatomical and administration parameters were among the five most important parameters for both sprays. Furthermore, variable importance assessment, based on the variance of the response, demonstrated the tip-to-INV distance as the most important parameter for Nasacort and coronal angle for Flonase Sensimist, while cross sectional area at the end of the anterior piece was the only parameter that found to be in the three most important parameters for both sprays. Having this in mind, as well as the wide range of PDD within the pediatric population, it can be concluded that the performance of targeted intranasal drug delivery, even when using a set of patient-specific administration parameters, is strongly influenced by the anatomical features of the subject. Additionally, comparing the key factors in predicting PDD in pediatric and adult population for Flonase Sensimist demonstrate no similarity between the influential parameters on PDD in the two age groups, which further emphasizes the importance of airway anatomy.

Preclinical Insights into the Role of Kir4.1 in Chronic Pain and Depression: Mechanisms and Therapeutic Potential

Chronic pain and mental health disorders, such as depression and anxiety, frequently co-occur and share underlying mechanisms involving neuronal excitability and synaptic transmission. The inwardly rectifying potassium channel 4.1 (Kir4.1), predominantly expressed in glial cells, is crucial for maintaining extracellular potassium and glutamate homeostasis. Dysregulation of Kir4.1 leads to altered neuronal activity, contributing to both chronic pain and mental health disorders. In chronic pain, downregulation of Kir4.1 impairs potassium buffering and glutamate clearance, increasing neuronal excitability and enhancing pain signaling through peripheral and central sensitization. In mental health disorders, impaired Kir4.1 function disrupts neurotrophic factor secretion and neuroinflammatory pathways, leading to mood disturbances. This review primarily summarizes findings from preclinical studies to examine the relationship between Kir4.1 and the pathogenesis of chronic pain and mental health disorders, discussing its molecular structure, expression patterns, and functional roles. Furthermore, we explore therapeutic strategies targeting Kir4.1, including pharmacological modulators and gene therapy approaches, emphasizing its potential as a novel therapeutic target.

Exploring the Therapeutic Potential of Terpenoids for Depression and Anxiety

This review focus on the terpenoids as potential therapeutic agents for depression and anxiety disorders, which naturally found in a variety of plants and exhibit a wide range of biological activities. Among the terpenoids discussed in this review are α-pinene, β-caryophyllene, α-phellandrene, limonene, β-linalool, 1, 8-cineole, β-pinene, caryophyllene oxide, p-cymene, and eugenol. All of these compounds have been studied extensively regarding their pharmacological properties, such as neuroprotective effect, anti-inflammation, antibacterial, regulation of neurotransmitters and antioxidant effect. Preclinical evidence are reviewed to highlight their diverse mechanisms of action and therapeutic potential to support antidepressant and anxiolytic properties. Additionally, challenges and future directions are also discussed to emphasize therapeutic utility of terpenoids for mental health disorders. Overall, this review provides a promising role of terpenoids as novel therapeutic agents for depression and anxiety, with potential implications for the development of more effective and well-tolerated treatments in the field of psychopharmacology.

Intranasal Therapy in Palliative Care

In recent years, the use of the intranasal route has been actively explored as a possible drug delivery method in the palliative patient population. There are reports demonstrating the effectiveness of nasally administered medications that are routinely used in patients at the end of life. The subject of this study is the intranasal drug administration among palliative patients. The aim is to summarize currently used intranasal therapies among palliative patients, determine the benefits and difficulties, and identify potential areas for future research. A review of available medical literature published between 2013 and 2023 was performed using online scientific databases. The following descriptors were used when searching for articles: "palliative", "intranasal", "nasal", "end-of-life care", "intranasal drug delivery" and "nasal drug delivery". Out of 774 articles, 55 directly related to the topic were finally selected and thoroughly analyzed. Based on the bibliographic analysis, it was shown that drugs administered intranasally may be a good, effective, and convenient form of treatment for patients receiving palliative care, in both children and adults. This topic requires further, high-quality clinical research.

Research progress in brain-targeted nasal drug delivery

The unique anatomical and physiological connections between the nasal cavity and brain provide a pathway for bypassing the blood-brain barrier to allow for direct brain-targeted drug delivery through nasal administration. There are several advantages of nasal administration compared with other routes; for example, the first-pass effect that leads to the metabolism of orally administered drugs can be bypassed, and the poor compliance associated with injections can be minimized. Nasal administration can also help maximize brain-targeted drug delivery, allowing for high pharmacological activity at lower drug dosages, thereby minimizing the likelihood of adverse effects and providing a highly promising drug delivery pathway for the treatment of central nervous system diseases. The aim of this review article was to briefly describe the physiological structures of the nasal cavity and brain, the pathways through which drugs can enter the brain through the nose, the factors affecting brain-targeted nasal drug delivery, methods to improve brain-targeted nasal drug delivery systems through the application of related biomaterials, common experimental methods used in intranasal drug delivery research, and the current limitations of such approaches, providing a solid foundation for further in-depth research on intranasal brain-targeted drug delivery systems (see Graphical Abstract).

Blood-Brain Barrier (BBB)-Crossing Strategies for Improved Treatment of CNS Disorders

Blood-brain barrier (BBB) is a special biological property of the brain neurovascular unit (including brain microvessels and capillaries), which facilitates the transport of nutrients into the central nervous system (CNS) and exchanges metabolites but restricts passage of blood-borne neurotoxic substances and drugs/xenobiotics into CNS. BBB plays a crucial role in maintaining the homeostasis and normal physiological functions of CNS but severely impedes the delivery of drugs and biotherapeutics into CNS for treatment of neurological disorders. A variety of technologies have been developed in the past decade for brain drug delivery. Most of these technologies are still in preclinical stage and some are undergoing clinical studies. Only a few have been approved by regulatory agencies for clinical applications. This chapter will overview the strategies and technologies/approaches for brain drug delivery and discuss some of the recent advances in the field.

Formulation, Characterization, and Evaluation of β-Cyclodextrin Functionalized Hypericin Loaded Nanocarriers

St. John's wort in western Europe has been extensively utilized for the treatment of mild to moderate depression. Hypericin, a red pigment, is found to be responsible for its antidepressant activity. The aim of the current study was to prepare a nanoemulsion (O/W) of hypericin designed for immediate delivery of the drug to the brain for the treatment of depression. The nanoemulsion was prepared by means of a homogenization technique, and that was followed by its physicochemical evaluation. Tween-80, Span-80, β-cyclodextrin, ethanol, and eucalyptus oil were utilized for the manufacturing of the nanoemulsion. Morphological studies have revealed globular structures of nanosize that were confirmed by the zeta analysis. The consistency of particles was revealed by the low polydispersity values. pH values of all formulations lay within the range of nasal pH. The viscosity of the prepared formulations was affected by the increase in concentrations of β-cyclodextrin. After passing from the centrifugation and freeze-thaw studies, the prepared formulations showed good stability. Formulation F2 having a composition of oil phase (0.125 mL), aqueous phase (1.25 mL), and β-cyclodextrin (8%) showed the best results out of all the formulations, and F2 had a pH of 5.7, 5.35 cP viscosity, 1.332 refractive index, 148.8 globule size, and -10.8 zeta potential. The mean percentage drug release and in vitro and ex vivo percentage drug permeations were observed to be 71.75, 76, and 75.07%, respectively. Meanwhile, formulation F2 showed the maximum drug release and permeation. In vivo behavior studies including the open field test, elevated plus maze test, and tail suspension test were conducted to see the antidepressant effect of hypericin along with comparison with a commercially available treatment. In conclusion, the prepared formulation shows good efficacy as an antidepressant and can be considered as a natural alternative over synthetic drugs.

Peptide-metal nanohybrids (PMN): Promising entities for combating neurological maladies

Nanotherapeutics are gaining traction in the modern scenario because of their unique and distinct properties which separate them from macro materials. Among the nanoparticles, metal NPs (MNPs) have gained importance due to their distinct physicochemical and biological characteristics. Peptides also exhibit several important functions in humans. Different peptides have received approval as pharmaceuticals, and clinical trials have been commenced for several peptides. Peptides are also used as targeting ligands. Considering all the advantages offered by these two entities, the conjugation of MNPs with peptides has emerged as a potential strategy for achieving successful targeting, diagnosis, and therapy of various neurological pathologies.