Melanin-like polydopamine nanoparticles mediating anti-inflammatory and rescuing synaptic loss for inflammatory depression therapy

Discovery of gallic acid-based mitochondriotropic antioxidant attenuates LPS-induced neuroinflammation

Mitochondria are complex organelle that plays a pivotal role in energy metabolism, regulation of stress responses, and also serve as a major hub for biosynthetic processes. In addition to their well-established function in cellular energetics, it also serves as the primary site for the origin of intracellular reactive oxygen species (ROS), which function as signaling molecules and can lead to oxidative stress when generated in excess. Moreover, mitochondrial dysfunction is one of the leading cause of neuroinflammation. In this regard, we have rationally designed a triazine derived mitochondriotropic antioxidants (Mito-TBA), based on gallic acid and triphenylphosphonium (TPP) cation to specifically target mitochondria to mitigate neuroinflammation. In vitro Mito-TBA-3 inhibits mitoautophagy, offers neuroprotection by inhibiting the LPS induced TLR-4 activation and activating the Nrf-2/ARE pathway in PC-12 derived neurons. In vivo Mito-TBA-3 rescue memory deficit, reversed depression like behavior, inhibited neuroinflammation, and decreased proinflammatory cytokines in LPS induced neuroinflammation rat model. Overall, based on biophysical, in vitro and in vivo analysis, Mito-TBA-3 offers valuable insights as a potent therapeutic lead molecule to combat neurodegeneration even outperforming a well-known non-steroidal anti-inflammatory drug (Aspirin), it also has the potential to use as a promising therapeutic candidate for other mitochondrial oxidative stress related disorders.

Pinocembrin alleviates LPS-induced depressive-like behavior in mice via the NLRP3/DCC signaling pathway

OBJECTIVE

Depression, a prevalent and severe mental disorder, continues to be a significant area of research concerning its pathogenesis and therapeutic approaches. Conventional antidepressants are often limited by delayed therapeutic effects and notable adverse reactions, necessitating the development of innovative and efficacious treatment modalities. Multiple lines of evidence suggest that peripheral and central inflammation play a role in depression, and that anti-inflammatory drugs can ameliorate depressive symptoms in patients with inflammation-related depression. Pinocembrin (PB), a natural bioactive compound, is renowned for its anti-inflammatory and antioxidant properties, while the effect and mechanism of PB are still unclear. Consequently, this study employs PB as an intervention to investigate its effects on depression in mice model, with the objective of establishing a novel therapeutic strategy and foundational data for the treatment of depression.

METHODS

(1) The acute inflammation model used lipopolysaccharide (LPS) to induce depression-like behavior in mice by injecting LPS intraperitoneally at a dose of 0.83 mg/kg. The effects of PB (20 mg/kg, i.p.) and the NLRP3 inflammasome inhibitor MCC950 (10 mg/kg, i.p.) on improving depression behavior in mice were evaluated. (2) To explore the specific mechanism of PB in improving depression-like behavior in LPS mice by regulating NLRP3 and Netrin-1/DCC pathway.

RESULTS

The results showed that after intraperitoneal injection of LPS, the mice exhibited a significant decrease in body weight, sucrose preference score, and a significant increase in tail suspension immobility time. Treatment with PB and MCC950 increased the sucrose preference score and decreased the tail suspension immobility time. Besides, PB and MCC950 could inhibit the expression of NLRP3 related neuroinflammation, down-regulated the Netrin-1/DCC signaling pathway, and improved hippocampal neuroplasticity in mice.

CONCLUSION

In conclusion, PB significantly improved LPS-induced depression-like behavior in mice by reducing the expression of hippocampal NLRP3 inflammasome and down-regulating the Netrin-1/DCC signaling pathway. Additionally, PB was found to regulate α-amino-3-hydroxy-5-methyl-4 isoxazole receptor (AMPAR) and postsynaptic density 95 (PSD95), protecting excitatory synaptic transmission and enhancing synaptic plasticity. This study demonstrates the effectiveness of PB in improving depressive symptoms induced by LPS and provides a new strategy for the clinical treatment of depression.

Polydopamine(PDA)-coated diselenide-bridged mesoporous silica-based nanoplatform for neuroprotection by reducing oxidative stress and targeting neuroinflammation in intracerebral hemorrhage

Oxidative stress (OS) and neuroinflammation are critical pathological processes in secondary brain injury (SBI) after intracerebral hemorrhage(ICH), and their intimate interactions initiate and aggravate brain damage. Thus, targeting oxidative stress and neuroinflammation could be a promising therapeutic strategy for ICH treatment. Here, we report a high-performance platform using polydopamine (PDA)-coated diselenide bridged mesoporous silica nanoparticle (PDA-DSeMSN) as a smart ROS scavenger and ROS-responsive drug delivery system. Caffeic acid phenethyl ester (CAPE) was blocked in the pore of DSeMSN by covering the pore with PDA as a gatekeeper. PDA-DSeMSN @CAPE maintained high stability and underwent reactive oxygen species (ROS)-responsive degradation and drug release. The intelligent nanomaterial effectively eliminated ROS, promoted M1 to M2 microglial conversion and suppressed neuroinflammation in vitro and in vivo. Importantly, intravenous administration of PDA-DSeMSN@CAPE specifically accumulated in perihematomal sites and demonstrated robust neuroprotection in an ICH mouse model with high biological safety. Taking together, the synergistic effect of ROS-responsive drug delivery ability and ROS scavenging ability of PDA-DSeMSN makes it a powerful drug delivery platform and provided new considerations into the therapeutic action to improve ICH-induce brain injury.

Nanoparticle-Based Drug Delivery Systems Enhance Treatment of Cognitive Defects

Nanoparticle-based drug delivery presents a promising solution in enhancing therapies for neurological diseases, particularly cognitive impairment. These nanoparticles address challenges related to the physicochemical profiles of drugs that hinder their delivery to the central nervous system (CNS). Benefits include improved solubility due to particle size reduction, enhanced drug penetration across the blood-brain barrier (BBB), and sustained release mechanisms suitable for long-term therapy. Successful application of nanoparticle delivery systems requires careful consideration of their characteristics tailored for CNS delivery, encompassing particle size and distribution, surface charge and morphology, loading capacity, and drug release kinetics. Literature review reveals three main types of nanoparticles developed for cognitive function enhancement: polymeric nanoparticles, lipid-based nanoparticles, and metallic or inorganic nanoparticles. Each type and its production methods possess distinct advantages and limitations. Further modifications such as coating agents or ligand conjugation have been explored to enhance their brain cell uptake. Evidence supporting their development shows improved efficacy outcomes, evidenced by enhanced cognitive function assessments, modulation of pro-oxidant markers, and anti-inflammatory activities. Despite these advancements, clinical trials validating the efficacy of nanoparticle systems in treating cognitive defects are lacking. Therefore, these findings underscore the need for researchers to expedite clinical testing to provide robust evidence of the potential of nanoparticle-based drug delivery systems.

Mussel-like polydopamine-assisted aggregation-induced emission nanodot for enhanced broad-spectrum antimicrobial activity: In vitro and in vivo validation

Emerging luminogens with aggregation-induced emission properties, namely AIEgens, demonstrated excellent anti-bacteria activity potential. However, their application still limited by the low antibacterial activity caused by the poor binding with bacteria. Polydopamine (PDA), an important biological macromolecule, possesses superior adhesion ability toward various material surface, including bacteria. In this study, the novel mussel-like PDA-assisted AIE Nanodot was proposed, achieving with robust bacterial binding ability and enhanced broad-spectrum antibacterial activity. Binding ability inherited from the PDA enables the constructed PDA-assisted AIE Nanodot to adhere efficiently to the bacterial membrane surface. Meanwhile, the AIE properties endowed them with monitoring capability, allowing for tracking their interaction with bacteria through facile fluorescence imaging in real time. More importantly, excellent killing of both Gram-positive and Gram-negative bacteria were successfully achieved in vitro antibacterial tests with excellent biocompatibility. Furthermore, in the treatment of Methicillin-resistant S. aureus (MRSA)-infected mouse-wound model, the mice exhibited accelerated wound healing with low bacterial load. This novel integrated strategy introduced a simple but effectively design to enhance the binding and antibacterial ability of AIEgens and would diversify the existing pool of antibacterial agents.

Metabolic engineering of Corynebacterium crenatum for enhanced L-tyrosine production from mannitol and glucose

BACKGROUND

L-Tyrosine (L-Tyr) is a significant aromatic amino acid that is experiencing an increasing demand in the market due to its distinctive characteristics. Traditional production methods exhibit various limitations, prompting researchers to place greater emphasis on microbial synthesis as an alternative approach.

RESULTS

Here, we developed a metabolic engineering-based method for efficient production of L-Tyr from Corynebacterium crenatum, including the elimination of competing pathways, the overexpression of aroB, aroD, and aroE, and the introduction of the mutated E. coli tyrAfbr gene for elevating L-Tyr generation. Moreover, the mtlR gene was knocked out, and the mtlD and pfkB genes were overexpressed, allowing C. crenatum to produce L-Tyr from mannitol. The L-Tyr production achieved 6.42 g/L at a glucose-to-mannitol ratio of 3:1 in a shake flask, which was 16.9% higher than that of glucose alone. Notably, the L-Tyr production of the fed-batch fermentation was elevated to 34.6 g/L, exhibiting the highest titers among those of C. glutamicum previously reported.

CONCLUSION

The importance of this research is underscored by its pioneering application of mannitol as a carbon source for the biosynthesis of L-Tyr, as well as its examination of the influence of mannitol-associated genes in microbial metabolism. A promising platform is provided for the production of target compounds that does not compete with human food source.

Phenolic-enabled nanotechnology: a new strategy for central nervous system disease therapy

Polyphenolic compounds have received tremendous attention in biomedicine because of their good biocompatibility and unique physicochemical properties. In recent years, phenolic-enabled nanotechnology (PEN) has become a hotspot of research in the medical field, and many promising studies have been reported, especially in the application of central nervous system (CNS) diseases. Polyphenolic compounds have superior anti-inflammatory and antioxidant properties, and can easily cross the blood‒brain barrier, as well as protect the nervous system from metabolic damage and promote learning and cognitive functions. However, although great advances have been made in this field, a comprehensive review regarding PEN-based nanomaterials for CNS therapy is lacking. A systematic summary of the basic mechanisms and synthetic strategies of PEN-based nanomaterials is beneficial for meeting the demand for the further development of novel treatments for CNS diseases. This review systematically introduces the fundamental physicochemical properties of PEN-based nanomaterials and their applications in the treatment of CNS diseases. We first describe the different ways in which polyphenols interact with other substances to form high-quality products with controlled sizes, shapes, compositions, and surface chemistry and functions. The application of PEN-based nanomaterials in the treatment of CNS diseases is then described, which provides a reference for subsequent research on the treatment of CNS diseases.

Remimazolam ameliorates postoperative cognitive dysfunction after deep hypothermic circulatory arrest through HMGB1-TLR4-NF-κB pathway

BACKGROUND

Postoperative cognitive dysfunction (POCD) is a complication of deep hypothermic circulatory arrest (DHCA). Various amounts of neurologic dysfunctions have been shown after DHCA, which has often been attributed to systemic inflammatory response syndrome and cerebral ischemia/reperfusion injury. Remimazolam is one of the commonly used anesthetic drugs with protective actions against inflammatory diseases, such as sepsis and cerebral ischemia/reperfusion injury. Here, we determined the protective effect and potential mechanism of action of remimazolam against neuronal damage after DHCA.

METHODS

A rat model of DHCA was established, and a gradient dosage of remimazolam was administered during cardiopulmonary bypass (CPB). The cognitive function of rats was evaluated by Morris water maze. Hematoxylin and eosin and TUNEL staining were performed to assess hippocampus tissue injury and neuronal apoptosis. Inflammatory cytokines concentration were analyzed by enzyme-linked immunosorbent assay. The protein expression was analyzed using automated electrophoresis western analysis and immunohistochemical analysis.

RESULTS

The appropriate dosage of remimazolam reduced histologic injury, neuronal apoptosis, microglia activation, and secondary inflammatory cascades, as well as the downregulation of the expression of the HMGB1-TLR4-NF-κB pathway after DHCA, improved the memory and learning abilities in DHCA rats. Further, administration of a TLR4 antagonist TAK-242 had a similar effect to remimazolam, while the TLR4 agonist LPS attenuated the effect of remimazolam.

CONCLUSIONS

Remimazolam could ameliorate POCD after DHCA through the HMGB1-TLR4-NF-κB signaling pathway.

Sustained Release of Nitric Oxide-Mediated Angiogenesis and Nerve Repair by Mussel-Inspired Adaptable Microreservoirs for Brain Traumatic Injury Therapy

Traumatic brain injury (TBI) triggers inflammatory response and glial scarring, thus substantially hindering brain tissue repair. This process is exacerbated by the accumulation of activated immunocytes at the injury site, which contributes to scar formation and impedes tissue repair. In this study, a mussel-inspired nitric oxide-release microreservoir (MINOR) that combines the features of reactive oxygen species (ROS) scavengers and sustained NO release to promote angiogenesis and neurogenesis is developed for TBI therapy. The injectable MINOR fabricated using a microfluidic device exhibits excellent monodispersity and gel-like self-healing properties, thus allowing the maintenance of its structural integrity and functionality upon injection. Furthermore, polydopamine in the MINOR enhances cell adhesion, significantly reduces ROS levels, and suppresses inflammation. Moreover, a nitric oxide (NO) donor embedded into the MINOR enables the sustained release of NO, thus facilitating angiogenesis and mitigating inflammatory responses. By harnessing these synergistic effects, the biocompatible MINOR demonstrates remarkable efficacy in enhancing recovery in mice. These findings benefit future therapeutic interventions for patients with TBI.

Identification of Specific Plasma miRNAs as Potential Biomarkers for Major Depressive Disorder

BACKROUND

Depression is a significant concern in clinical and preclinical psychoneurobiological sciences due to its high prevalence and its individual and collective consequences. Identifying efficient biomarkers for accurate diagnosis is crucial, with ideal biomarkers having detectable serum levels and conformational and thermal stability. This study aims to identify stable plasma biomarkers for the diagnosis and prognosis of major depressive disorder, as the pathogenesis of the disorder remains incompletely understood, affecting diagnosis accuracy.

METHODS

Thus, this study included ten MDD patients and eight healthy controls. The present work analyzed miRNAs in patients with major depressive disorder compared to healthy controls.

RESULTS

Eleven specific miRNAs, particularly hsa-miR-874-3p; hsa-let-7d-5p; and hsa-miR-93-3p showed upregulation-type plasma variations in the group of patients with major depressive disorder. miRNA functionality is linked to depressive pathophysiology.

CONCLUSIONS

This study identifies a "bouquet" of miRNAs with significant upregulation variations in patients with major depressive disorder, suggesting further research to determine their suitability for personalization and evaluation, ultimately becoming integral components of major depression serological evaluations.

Multifunctionally disordered TiO2 nanoneedles prevent periprosthetic infection and enhance osteointegration by killing bacteria and modulating the osteoimmune microenvironment

Rationale: Total hip arthroplasty (THA) and total knee arthroplasty (TKA) are effective interventions for end-stage osteoarthritis; however, periprosthetic infection is a devastating complication of arthroplasty. To safely prevent periprosthetic infection and enhance osteointegration, the surface modification strategy was utilized to kill bacteria, modulate the osteoimmune microenvironment, and improve new bone formation. Methods: We used the hydrothermal method to fabricate a bionic insect wing with the disordered titanium dioxide nanoneedle (TNN) coating. The mussel-inspired poly-dopamine (PDA) and antibacterial silver nanoparticles (AgNPs) were coated on TNN, named AgNPs-PDA@TNN, to improve the biocompatibility and long-lasting bactericidal capacity. The physicochemical properties of the engineered specimen were evaluated with SEM, AFM, XPS spectrum, and water contact assay. The biocompatibility, bactericidal ability, and the effects on macrophages and osteogenic differentiation were assessed with RT-qPCR, Western blotting, live/dead staining, immunofluorescent staining, etc. Results: The AgNPs-PDA@TNN were biocompatible with macrophages and exhibited immunomodulatory ability to promote M2 macrophage polarization. In addition, AgNPs-PDA@TNN ameliorated the cytotoxicity caused by AgNPs, promoted cell spreading, and increased osteogenesis and matrix deposition of BMSCs. Furthermore, AgNPs-PDA@TNN exhibited bactericidal ability against E. coli and S. aureus by the bionic nanostructure and coated AgNPs. Various imaging analyses indicated the enhanced bactericidal ability and improved new bone formation by AgNPs-PDA@TNN in vivo. H&E, Gram, and Masson staining, verified the improved bone formation, less inflammation, infection, and fibrosis encapsulation. The immunofluorescence staining confirmed the immunomodulatory ability of AgNPs-PDA@TNN in vivo. Conclusion: The bionic insect wing AgNPs-PDA@TNN coating exhibited bactericidal property, immunomodulatory ability, and enhanced osteointegration. Thus, this multidimensional bionic implant surface holds promise as a novel strategy to prevent periprosthetic infection.

Application of biomaterials in the treatment of intracerebral hemorrhage

Although the current surgical hematoma removal treatment saves patients' lives in critical moments of intracerebral hemorrhage (ICH), the lethality and disability rates of ICH are still very high. Due to the individual differences of patients, postoperative functional improvement is still to be confirmed, and the existing drug treatment has limited benefits for ICH. Recent advances in biomaterials may provide new ideas for the therapy of ICH. This review first briefly describes the pathogenic mechanisms of ICH, including primary and secondary injuries such as inflammation and intracerebral edema, and briefly describes the existing therapeutic approaches and their limitations. Secondly, existing nanomaterials and hydrogels for ICH, including exosomes, liposomes, and polymer nanomaterials, are also described. In addition, the potential challenges and application prospects of these biomaterials for clinical translation in ICH treatment are discussed.

Biomaterial strategies for regulating the neuroinflammatory response

Injury and disease in the central nervous system (CNS) can result in a dysregulated inflammatory environment that inhibits the repair of functional tissue. Biomaterials present a promising approach to tackle this complex inhibitory environment and modulate the mechanisms involved in neuroinflammation to halt the progression of secondary injury and promote the repair of functional tissue. In this review, we will cover recent advances in biomaterial strategies, including nanoparticles, hydrogels, implantable scaffolds, and neural probe coatings, that have been used to modulate the innate immune response to injury and disease within the CNS. The stages of inflammation following CNS injury and the main inflammatory contributors involved in common neurodegenerative diseases will be discussed, as understanding the inflammatory response to injury and disease is critical for identifying therapeutic targets and designing effective biomaterial-based treatment strategies. Biomaterials and novel composites will then be discussed with an emphasis on strategies that deliver immunomodulatory agents or utilize cell-material interactions to modulate inflammation and promote functional tissue repair. We will explore the application of these biomaterial-based strategies in the context of nanoparticle- and hydrogel-mediated delivery of small molecule drugs and therapeutic proteins to inflamed nervous tissue, implantation of hydrogels and scaffolds to modulate immune cell behavior and guide axon elongation, and neural probe coatings to mitigate glial scarring and enhance signaling at the tissue-device interface. Finally, we will present a future outlook on the growing role of biomaterial-based strategies for immunomodulation in regenerative medicine and neuroengineering applications in the CNS.

Multicomponent Pathogen-Mimicking Nanoparticles Induce Intestinal Immune Responses against Paratuberculosis

Given the worldwide problem posed by enteric pathogens, the discovery of safe and efficient intestinal adjuvants combined with novel antigen delivery techniques is essential to the design of mucosal vaccines. In this work, we designed poly (lactic-co-glycolic acid) (PLGA)-based nanoparticles (NPs) to codeliver all-trans retinoic acid (atRA), novel antigens, and CpG. To address the insolubility of the intestinal adjuvant atRA, we utilized PLGA to encapsulate atRA and form a "nanocapsid" with polydopamine. By leveraging polydopamine, we adsorbed the water-soluble antigens and the TLR9 agonist CpG onto the NPs' surface, resulting in the pathogen-mimicking PLPCa NPs. In this study, the novel fusion protein (HBf), consisting of the Mycobacterium avium subspecies paratuberculosis antigens HBHA, Ag85B, and Bfra, was coloaded onto the NPs. In vitro, PLPCa NPs were shown to promote the activation and maturation of bone marrow-derived dendritic cells. Additionally, we found that PLPCa NPs created an immune-rich microenvironment at the injection site following intramuscular administration. From the results, the PLPCa NPs induced strong IgA levels in the gut in addition to enhancing powerful systemic immune responses. Consequently, significant declines in the bacterial burden and inflammatory score were noted in PLPCa NPs-treated mice. In summary, PLPCa can serve as a novel and safe vaccine delivery platform against gut pathogens, such as paratuberculosis, capable of activating both systemic and intestinal immunity.

Nanomaterials as Microglia Modulators in the Treatment of Central Nervous System Disorders

Microglia play a pivotal role in the central nervous system (CNS) homeostasis, acting as housekeepers and defenders of the surrounding environment. These cells can elicit their functions by shifting into two main phenotypes: pro-inflammatory classical phenotype, M1, and anti-inflammatory alternative phenotype, M2. Despite their pivotal role in CNS homeostasis, microglia phenotypes can influence the development and progression of several CNS disorders such as Alzheimer's disease, Parkinson's disease, amyotrophic lateral sclerosis, multiple sclerosis, ischemic stroke, traumatic brain injuries, and even brain cancer. It is thus clear that the possibility of modulating microglia activation has gained attention as a therapeutic tool against many CNS pathologies. Nanomaterials are an unprecedented tool for manipulating microglia responses, in particular, to specifically target microglia and elicit an in situ immunomodulation activity. This review focuses the discussion on two main aspects: analyzing the possibility of using nanomaterials to stimulate a pro-inflammatory response of microglia against brain cancer and introducing nanostructures able to foster an anti-inflammatory response for treating neurodegenerative disorders. The final aim is to stimulate the analysis of the development of new microglia nano-immunomodulators, paving the way for innovative and effective therapeutic approaches for the treatment of CNS disorders.

ROS scavenging activity of polydopamine nanoparticle-loaded supramolecular gelatin-based hydrogel promoted cardiomyocyte proliferation

Reactive oxygen species (ROS) play essential roles in cellular functions, but maintaining ROS balance is crucial for effective therapeutic interventions, especially during cell therapy. In this study, we synthesized an injectable gelatin-based hydrogel, in which polydopamine nanoparticles were entrapped using supramolecular interactions. The surfaces of the nanoparticles were modified using adamantane, enabling their interactions with β-cyclodextrin-conjugated with gelatin. We evaluated the cytotoxicity and antioxidant properties of the hydrogel on neonatal rat cardiomyocytes (NRCM), where it demonstrated the ability to increase the metabolic activity of NRCMs exposed to hydrogen peroxide (H2O2) after 5 days. Hydrogel-entrapped nanoparticle exhibited a high scavenging capability against hydroxyl radical, 1'-diphenyl-2-picrylhydrazyl radicals, and H2O2, surpassing the effectiveness of ascorbic acid solution. Notably, the presence of polydopamine nanoparticles within the hydrogel promoted the proliferation activity of NRCMs, even in the absence of excessive ROS due to H2O2 treatment. Additionally, when the hydrogel with nanoparticles was injected into an air pouch model, it reduced inflammation and infiltration of immune cells. Notably, the levels of anti-inflammatory factors, IL-10 and IL-4, were significantly increased, while the pro-inflammatory factor TNF-α was suppressed. Therefore, this novel ROS-scavenging hydrogel holds promise for both efficient cell delivery into inflamed tissue and promoting tissue repair.

SynCAM1 deficiency in the hippocampal parvalbumin interneurons contributes to sevoflurane-induced cognitive impairment in neonatal rats

AIMS

Sevoflurane is widely used for general anesthesia in children. Previous studies reported that multiple neonatal exposures to sevoflurane can induce long-term cognitive impairment in adolescent rats, but the underlying mechanisms were not defined.

METHODS

Postnatal day 6 (P6) to P8 rat pups were exposed to 30% oxygen with or without 3% sevoflurane balanced with air. The Y maze test (YMT) and Morris water maze (MWM) tests were performed in some cohorts from age P35 to assess cognitive functions, and their brain samples were harvested at age P14, 21, 28, 35, and 42 for measurements of various molecular entities and in vivo electrophysiology experiments at age P35.

RESULTS

Sevoflurane exposure resulted in cognitive impairment that was associated with decreased synCAM1 expression in parvalbumin (PV) interneurons, a reduction of PV phenotype, disturbed gamma oscillations, and dendritic spine loss in the hippocampal CA3 region. Enriched environment (EE) increased synCAM1 expression in the PV interneurons and attenuated sevoflurane-induced cognitive impairment. The synCAM1 overexpression by the adeno-associated virus vector in the hippocampal CA3 region restored sevoflurane-induced cognitive impairment, PV phenotype loss, gamma oscillations decrease, and dendritic spine loss.

CONCLUSION

Our data suggested that neonatal sevoflurane exposure results in cognitive impairment through decreased synCAM1 expression in PV interneurons in the hippocampus.

Clemastine-induced enhancement of hippocampal myelination alleviates memory impairment in mice with chronic pain

Patients with chronic pain often experience memory impairment, but the underlying mechanisms remain elusive. The myelin sheath is crucial for rapid and accurate action potential conduction, playing a pivotal role in the development of cognitive abilities in the central nervous system. The study reveals that myelin degradation occurs in the hippocampus of chronic constriction injury (CCI) mice, which display both chronic pain and memory impairment. Using fiber photometry, we observed diminished task-related neuronal activity in the hippocampus of CCI mice. Interestingly, the repeated administration with clemastine, which promotes myelination, counteracts the CCI-induced myelin loss and reduced neuronal activity. Notably, clemastine specifically ameliorates the impaired memory without affecting chronic pain in CCI mice. Overall, our findings highlight the significant role of myelin abnormalities in CCI-induced memory impairment, suggesting a potential therapeutic approach for treating memory impairments associated with neuropathic pain.

Polydopamine nanomaterials and their potential applications in the treatment of autoimmune diseases

The conventional treatment methods used for the management of autoimmune diseases (ADs) have limited efficacy and also exhibit significant side effects. Thus, identification of novel strategies to improve the efficacy and safety of ADs treatment is urgently required. Overactivated immune response and oxidative stress are common characteristics associated with ADs. Polydopamine (PDA), as a polymer material with good antioxidant and photothermal conversion properties, has displayed useful application potential against ADs. In addition, PDA possesses good biosafety, simple preparation, and easy functionalization, which is conducive for the pharmacological development of PDA nanomaterials with clinical transformation prospects. Here, we have first reviewed the preparation of PDA, the different functional integration strategies of PDA-based biomaterials, and their potential applications in ADs. Next, the mechanism of action of PDA in ADs has been elaborated in detail. Finally, the application opportunities and challenges linked with PDA nanomaterials for ADs treatment are discussed. This review is contributed to design reasonable and effective PDA nanomaterials for the diagnosis and treatment of ADs.

Cell-nano interactions of polydopamine nanoparticles

Polydopamine (PDA) nanoparticles (NPs) have diverse nanomedicine applications owing to their biocompatibility and abundant entry to cells. Yet, our knowledge in their interactions with cells was infrequently studied until recent years. This review presents the latest insights into the cell-nano interactions of PDA NPs, including their 'self-targeting' to dopamine receptors for cellular entry without the aid of ligands, in vitro 'self-therapeutic' cellular responses (antiferroptosis, macrophage polarization, and modulation of mitochondrial bioenergetics) in the absence of drugs, and in vivo cellular localization and pharmacological properties upon various routes of administration. This review concludes with our perspectives on the therapeutic promise of PDA NPs and the need for studies on PDA biochemistry, biodegradability, and protein adsorption.

Superoxide Dismutase-Like Regulated Fe/Ppa@PDA/B for Synergistically Targeting Ferroptosis/Apoptosis to Enhance Anti-Tumor Efficacy

The cell apoptosis pathway of sonodynamic therapy (SDT) is usually blocked, resulting in limited therapeutic efficacy, therefore, the development of new methods for sensitizing targeted ferroptosis and promoting apoptosis is of great significance to improve the anti-tumor efficacy of SDT. Herein, mesoporous Fe3 O4 nanoparticles (NPs) are synthesized for loading pyropheophorbide-a (ppa), surface-coated by polydopamine (PDA) and further anchored with tumor-targeting moieties of biotin to obtain Fe/ppa@PDA/B NPs. Fe/ppa@PDA/B displayes pH/ultrasound (US) responsive release properties, and magnetic resonance imaging (MRI) functions. Moreover, Fe3 O4 NPs of Fe/ppa@PDA/B as the Fe source for ferroptosis, enhances ferroptosis sensitivity by consuming glutathione (GSH) and producing hydroxyl radical (OH). The quinone groups of PDA layer on Fe/ppa@PDA/B own free electrons, which led to effective superoxide dismutase (SOD) action through superoxide anion (O2 - ) disproportionation to hydrogen peroxide (H2 O2 ) and oxygen (O2 ), thus, overcame hypoxia of SDT and promoted ·OH generation by Fe ions under US trigger, synergistically improves ferroptosis and apoptosis to enhance the anti-tumor efficacy of SDT both in vitro and in vivo. The anti-tumor strategy of synergistic apoptosis and ferroptosis induce by GSH depletion and self-sufficient O2 regulated by SOD provides a new idea for enhancing SDT efficacy.

Nanopharmacology as a new approach to treat neuroinflammatory disorders

Neuroinflammation, a complex process involving the activation of microglia, astrocytes, and other immune cells in the brain, plays a role in neurodegeneration and psychiatric disorders. Current therapeutic strategies for neuroinflammation are limited, necessitating the development of improved approaches. Nanopharmacology offers unprecedented opportunities to access and treat neuroinflammatory disorders at the brain level. Nanoscaffolds can target specific cells or tissues and protect drugs from degradation or elimination, making them ideal candidates for treating neurodegenerative and psychiatric diseases. Recent advancements in nanoparticle development have enabled the targeting of microglia, astrocytes, and other immune cells in the brain, reducing neuroinflammation and protecting neurons from injury. Nanoparticles targeting specific neurons have also been developed. Clinical trials are in progress to evaluate the safety and efficacy of nano drugs for treating neuroinflammatory, neurodegenerative, and psychiatric diseases. The successful development of these nanodrugs holds immense promise for treating these devastating and increasingly prevalent conditions. On the other hand, several limitations and unanswered questions remain. First, the long-term effects of nanoparticles on the brain need to be thoroughly investigated to ensure their safety. Second, optimizing the targeting and delivery of nanoparticles to specific brain regions remains a challenge. Understanding the complex interplay between nanoparticles and the brain's immune system is crucial for developing effective nanotherapies. Despite these limitations, nanopharmacology presents a transformative approach to treating neuroinflammatory disorders. Future research should address the aforementioned limitations and further elucidate the mechanisms of nanoparticle-mediated therapy. The successful development of safe and effective nanodrugs can revolutionize the treatment of neuroinflammatory disorders, alleviating the suffering of millions.