TAT-modified tetramethylpyrazine-loaded nanoparticles for targeted treatment of spinal cord injury

Bibliometric analysis of research progress on tetramethylpyrazine and its effects on ischemia-reperfusion injury

In recent decades, natural products have attracted worldwide attention and become one of the most important resources for pharmacological industries and medical sciences to identify novel drug candidates for disease treatment. Tetramethylpyrazine (TMP) is an alkaloid extracted from Ligusticum chuanxiong Hort., which has shown great therapeutic potential in cardiovascular and cerebrovascular diseases, liver and renal injury, as well as cancer. In this review, we analyzed 1270 papers published on the Web of Science Core Collection from 2002 to 2022 and found that TMP exerted significant protective effects on ischemia-reperfusion (I/R) injury that is the cause of pathological damages in a variety of conditions, such as ischemic stroke, myocardial infarction, acute kidney injury, and liver transplantation. TMP is limited in clinical applications to some extent due to its rapid metabolism, a short biological half-life and poor bioavailability. Obviously, the structural modification, administration methods and dosage forms of TMP need to be further investigated in order to improve its bioavailability. This review summarizes the clinical applications of TMP, elucidates its potential mechanisms in protecting I/R injury, provides strategies to improve bioavailability, which presents a comprehensive understanding of the important compound. Hopefully, the information and knowledge from this review can help researchers and physicians to better improve the applications of TMP in the clinic.

A lava-inspired proteolytic enzyme therapy on cancer with a PEG-based hydrogel enhances tumor distribution and penetration of liposomes

The enhanced permeability and retention (EPR) effect has become the guiding principle for nanomedicine against cancer for a long time. However, several biological barriers severely resist therapeutic agents' penetration and retention into the deep tumor tissues, resulting in poor EPR effect and high tumor mortality. Inspired by lava, we proposed a proteolytic enzyme therapy to improve the tumor distribution and penetration of nanomedicine. A trypsin-crosslinked hydrogel (Trypsin@PSA Gel) was developed to maintain trypsin's activity. The hydrogel postponed trypsin's self-degradation and sustained the release. Trypsin promoted the cellular uptake of nanoformulations in breast cancer cells, enhanced the penetration through endothelial cells, and degraded total and membrane proteins. Proteomic analysis reveals that trypsin affected ECM components and down-regulated multiple pathways associated with cancer progression. Intratumoral injection of Trypsin@PSA Gel significantly increased the distribution of liposomes in tumors and reduced tumor vasculature. Combination treatment with intravenous injection of gambogic acid-loaded liposomes and intratumoral injection of Trypsin@PSA Gel inhibited tumor growth. The current study provides one of the first investigations into the enhanced tumor distribution of liposomes induced by a novel proteolytic enzyme therapy.

Injectable Hydrogel To Deliver Bone Mesenchymal Stem Cells Preloaded with Azithromycin To Promote Spinal Cord Repair

Spinal cord injury is a disease that causes severe damage to the central nervous system. Currently, there is no cure for spinal cord injury. Azithromycin is commonly used as an antibiotic, but it can also exert anti-inflammatory effects by down-regulating M1-type macrophage genes and up-regulating M2-type macrophage genes, which may make it effective for treating spinal cord injury. Bone mesenchymal stem cells possess tissue regenerative capabilities that may help promote the repair of the injured spinal cord. In this study, our objective was to explore the potential of promoting repair in the injured spinal cord by delivering bone mesenchymal stem cells that had internalized nanoparticles preloaded with azithromycin. To achieve this objective, we formulated azithromycin into nanoparticles along with a trans-activating transcriptional activator, which should enhance nanoparticle uptake by bone mesenchymal stem cells. These stem cells were then incorporated into an injectable hydrogel. The therapeutic effects of this formulation were analyzed in vitro using a mouse microglial cell line and a human neuroblastoma cell line, as well as in vivo using a rat model of spinal cord injury. The results showed that the formulation exhibited anti-inflammatory and neuroprotective effects in vitro as well as therapeutic effects in vivo. These results highlight the potential of a hydrogel containing bone mesenchymal stem cells preloaded with azithromycin and trans-activating transcriptional activator to mitigate spinal cord injury and promote tissue repair.

Design and Self-Assembly of Peptide-Copolymer Conjugates into Nanoparticle Hydrogel for Wound Healing in Diabetes

Background

Delayed wound healing in skin injuries has become a significant problem in clinics, seriously affecting and even threatening life and health. Recently, research interest has increased in developing wound dressings containing bioactive compounds capable of improving outcomes for complex healing needs.

Methods

In this study, Puerarin-loaded nanoparticles (Pue-NPs) were prepared using the cell-penetrating peptide-poly (lactic-co-glycolic acid) (CPP-PLGA) as a drug carrier by the emulsified solvent evaporation method. Then, they were added into poly (acrylic acid) to obtain a self-assembled nanocomposite hydrogels (SANHs) drug delivery system using the co-polymerization method. The particle size, zeta potential, and micromorphology of Pue-NPs were measured; the appearance, mechanical properties, adhesive strength, and biological activity of SANHs were performed. Finally, the potential of SANHs for wound healing was further evaluated in streptozotocin-induced diabetic mice.

Results

Pue-NPs were regularly spherical, with an average particle size of 134.57 ± 1.42 nm and a zeta potential of 2.14 ± 0.78 mV. SANHs was colorless and transparent with a honeycomb-like porous structure and had an excellent swelling ratio (917%), water vapor transmission rate (3077 g·m-2·day-1), mechanical properties (Young's modulus of 18 kPa, elongation at break of 307%), and adhesive strength (15.5 kPa). SANHs exhibited sustained release of Pue over 48h, with a cumulative release of 55.60 ± 6.01%. In vitro tests revealed that the SANHs presented a 92.22% antibacterial rate against Escherichia coli after 4h, and a 61.91% scavenging rate of 1.1-diphenyl-2-trinitrophenylhydrazine (DPPH) radical. In vivo experiments showed that SANHs accelerated wound repair by reducing the inflammatory response at the wound site, promoting angiogenesis, and facilitating epidermal regeneration and collagen deposition.

Conclusion

In conclusion, we successfully prepared SANHs. Our results show that SANHs have excellent performance and improves wound healing in diabetic mice model, indicating that it can be used to develop an effective strategy for the treatment of diabetic wounds.

COVID-19 cooling: Nanostrategies targeting cytokine storm for controlling severe and critical symptoms

As severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants continue to wreak havoc worldwide, the "Cytokine Storm" (CS, also known as the inflammatory storm) or Cytokine Release Syndrome has reemerged in the public consciousness. CS is a significant contributor to the deterioration of infected individuals. Therefore, CS control is of great significance for the treatment of critically ill patients and the reduction of mortality rates. With the occurrence of variants, concerns regarding the efficacy of vaccines and antiviral drugs with a broad spectrum have grown. We should make an effort to modernize treatment strategies to address the challenges posed by mutations. Thus, in addition to the requirement for additional clinical data to monitor the long-term effects of vaccines and broad-spectrum antiviral drugs, we can use CS as an entry point and therapeutic target to alleviate the severity of the disease in patients. To effectively combat the mutation, new technologies for neutralizing or controlling CS must be developed. In recent years, nanotechnology has been widely applied in the biomedical field, opening up a plethora of opportunities for CS. Here, we put forward the view of cytokine storm as a therapeutic target can be used to treat critically ill patients by expounding the relationship between coronavirus disease 2019 (COVID-19) and CS and the mechanisms associated with CS. We pay special attention to the representative strategies of nanomaterials in current neutral and CS research, as well as their potential chemical design and principles. We hope that the nanostrategies described in this review provide attractive treatment options for severe and critical COVID-19 caused by CS.

Tetramethylpyrazine inhibits the inflammatory response by downregulating the TNFR1/IκB-α/NF-κB p65 pathway after spinal cord injury

Previous studies have demonstrated that tetramethylpyrazine (TMP) can enhance the recovery of motor function in spinal cord injury (SCI) rats. However, the underlying mechanism involved in this therapeutic effect remains to be elucidated. We conducted RNA sequencing with a network pharmacology strategy to predict the targets and mechanism of TMP for SCI. The modified Allen's weight-drop method was used to construct an SCI rat model. The results indicated that the nuclear transfer factor-κB (NF-κB) pathway was identified through the Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis, and an inflammatory response was identified through the Gene Ontology (GO) enrichment analysis. Tumor necrosis factor (TNF) was identified as a crucial target. Western blotting revealed that TMP decreased the protein expression of TNF superfamily receptor 1 (TNFR1), inhibitor κB-α (IκB-α), and NF-κB p65 in spinal cord tissues. Enzyme-linked immunosorbent assay (ELISA) and immunohistochemistry (IHC) demonstrated that TMP inhibited TNF-α, interleukin-1β (IL-1β), reactive oxygen species (ROS), and malondialdehyde (MDA) expression and enhanced superoxide dismutase (SOD) expression. Histopathological observation and behavior assessments showed that TMP improved morphology and motor function. In conclusion, TMP inhibits inflammatory response and oxidative stress, thereby exerting a neuroprotective effect that may be related to the regulation of the TNFR1/IκB-α/NF-κB p65 signaling pathway.

Neuroprotective effects of tetramethylpyrazine on spinal cord injury-Related neuroinflammation mediated by P2X7R/NLRP3 interaction

OBJECTIVE

The inflammatory response is acknowledged as a crucial pathological aspect of spinal cord injury (SCI). Tetramethylpyrazine (TMP) has been demonstrated to possess neuroprotective properties within the central nervous system via its anti-inflammatory mechanisms. This study aims to investigate the molecular mechanism by which TMP alleviates SCI from an anti-inflammatory standpoint.

METHODS

The SCI model was established using the MASCIS impactor device. The Basso-Beattie-Bresnahan (BBB) locomotor rating scale was utilised to assess rat locomotion. Nissl and Golgi staining were used to observe neuron and dendritic spine morphology, respectively. A transmission electron microscope was used to observe the microcosmic morphology of the axon. ELISA kits were used to measure the concentrations of IL-1β and IL-18 in the spinal cord. Immunofluorescence staining was used to detect P2X7R+/IBA-1+ cells, and Western blot and RT-qPCR were used to analyze the protein and mRNA expression of P2X7R in the spinal cord. Additionally, Western blot was used to detect NLRP3 and Cleaved-Caspase-1 (p20), the critical proteins in the NLRP3 inflammasome pathway.

RESULTS

TMP ameliorated the microcosmic morphology of the axon and had an inhibitory effect on the concentrations of IL-1β and IL-18 after SCI. Furthermore, TMP inhibited the expression of both P2X7R and critical proteins of the NLRP3 inflammasome pathway on microglia after SCI. The aforementioned effects of TMP exhibit similarities to those of BBG (P2X7R antagonist); however, they can be effectively reversed by BzATP (P2X7R activator).

CONCLUSION

TMP alleviated SCI via reducing tissue damage, neuroinflammation, and the expression of P2X7R, NLRP3, IL-1β, and IL-18.

High rapamycin-loaded hollow mesoporous Prussian blue nanozyme targets lesion area of spinal cord injury to recover locomotor function

Scavenging free radicals and reducing inflammatory reaction to relieve the secondary damage are important issues in the spinal cord injury (SCI) therapeutic strategy. Nanozymes attract more attention in the drug development of SCI due to the high stability, long-lasting catalytic capacity, and multienzyme-like properties. Herein, we constructed a Rapamycin (Rapa)-loaded and hollow mesoporous Prussian blue (HMPB)-based nanozyme (RHPAzyme) to realize the combined antioxidation and anti-inflammation combination therapy of SCI. Furthermore, activated cell penetrating peptide (ACPP) is modified onto nanozyme to endow the effectively ability of lesion area-targeting. This RHPAzyme exhibits ROS scavenging capacity with the transformation of Fe2+/Fe3+ valance and cyanide group of HMPB to achieve multienzyme-like activity. As expected, RHPAzyme scavenges the ROS overproduction and reduces inflammation in oxygen-glucose deprivation (OGD)-induced damage via inhibiting MAPK/AKT signaling pathway. Furtherly, RHPAzyme exhibits the combined antioxidant and anti-inflammatory activity in vivo, which can effectively alleviate neuronal damage and promote motor function recovery in SCI mice. Overall, this study demonstrates the RHPAzyme induces an effective treatment of SCI by inhibiting oxygen-mediated cell apoptosis and suppressing inflammation-induced injury, thus reduces the nervous impairment and promotes motor function recovery.

Tetramethylpyrazine promotes angiogenesis and nerve regeneration and nerve defect repair in rats with spinal cord injury

Objective

This study evaluated the regulatory effect of Tetramethylpyrazine (TMP) on the spinal cord injury (SCI) rat model and clarified the neuroprotective mechanism of TMP on SCI.

Methods

An SCI rat model was generated and treated with TMP injections for two weeks. miR-497-5p and EGFL7 expression changes were evaluated, motor function recovery after SCI was assessed by BBB score test and footprint analysis, lesions of rat spinal cord were assessed by HE staining and TUNEL staining; angiogenesis was assessed by immunoblotting for CD31; inflammatory factor levels were detected by ELISA. EGFL7 was verified as a target of miR-497-5p by bioinformatics website analysis and luciferase reporter gene assay. H2O2-injured neurons were cultured in vitro to explore the effect of TMP.

Results

After SCI, miR-497-5p was upregulated while EGFL7 was downregulated in rats. TMP inhibited apoptosis and promoted angiogenesis, nerve regeneration, and repair of nerve defects by reducing miR-497-5p and increasing EGFL7 expression. miR-497-5p targeted EGFL7. In addition, TMP hindered neuronal inflammation and apoptosis induced by H2O2in vitro.

Conclusion

TMP promotes angiogenesis by downregulating miR-497-5p to target EGFL7, and promotes nerve regeneration and repair of nerve defects in rats with SCI.

Nanomedicine innovations in spinal cord injury management: Bridging the gap

Spinal cord injury (SCI) has devastating effects on a person's physical, social, and professional well-being. It is a life-altering neurological condition that significantly impacts individuals and their caregivers on a socioeconomic level. Recent advancements in medical therapy have greatly improved the diagnosis, stability, survival rates, and overall well-being of SCI patients. However, there are still limited options available for enhancing neurological outcomes in these patients. The complex pathophysiology of SCI, along with the numerous biochemical and physiological changes that occur in the damaged spinal cord, contribute to this gradual improvement. Currently, there are no therapies that offer the possibility of recovery for SCI, although several therapeutic approaches are being developed. However, these therapies are still in the early stages and have not yet demonstrated effectiveness in repairing the damaged fibers, which hinders cellular regeneration and the full restoration of motor and sensory functions. Considering the importance of nanotechnology and tissue engineering in treating neural tissue injuries, this review focuses on the latest advancements in nanotechnology for SCI therapy and tissue healing. It examines research articles from the PubMed database that specifically address SCI in the field of tissue engineering, with an emphasis on nanotechnology as a therapeutic approach. The review evaluates the biomaterials used for treating this condition and the techniques employed to create nanostructured biomaterials.

Biomineral-binding liposomes with dual antibacterial effects for preventing and treating dental caries

Dental caries is a chronic oral disease that results from the demineralization of dental hard tissues caused by the long-term interaction of various pathogenic factors in the human oral cavity. Although magnolol (Mag) and fluconazole (FLC) have shown promising antibacterial activity against Candida albicans (C. albicans) and Streptococcus mutans (S. mutans), their clinical application is limited due to hydrophobicity. In this study, we constructed biomineral-binding liposomes co-loaded with Mag and FLC (PPi-Mag/FLC-LPs) to overcome the hydrophobicity and achieve a dual antibacterial activity in the acidic microenvironment of caries. PPi-Mag/FLC-LPs were characterized by laser particle size analysis, transmission electron microscopy, and high-performance liquid chromatography (HPLC). The ability of PPi-Mag/FLC-LPs to bind hydroxyapatite was assessed in vitro using fluorescence microscopy and HPLC, while the antibacterial activity was examined by measuring drug effects on the acidogenicity, acid resistance, biofilm formation and survival of C. albicans and S. mutans. The pharmacodynamics of PPi-Mag/FLC-LPs was also evaluated in vivo in a rat model of dental caries. Mag and FLC were released rapidly from PPi-Mag/FLC-LPs in a pH-sensitive manner, and they bound effectively to hydroxyapatite, leading to a better antibacterial effect on C. albicans and S. mutans compared to free drugs or liposomes loaded with a single drug. PPi-Mag/FLC-LPs improved the medicinal properties of Mag and FLC and provided a rapid, pH-sensitive release of both drugs in vitro. PPi-Mag/FLC-LPs displayed good antibacterial activity in vivo, showing promise as a dual-drug delivery system for the prevention and treatment of caries.

Human Serum Albumin Based Nanodrug Delivery Systems: Recent Advances and Future Perspective

With the success of several clinical trials of products based on human serum albumin (HSA) and the rapid development of nanotechnology, HSA-based nanodrug delivery systems (HBNDSs) have received extensive attention in the field of nanomedicine. However, there is still a lack of comprehensive reviews exploring the broader scope of HBNDSs in biomedical applications beyond cancer therapy. To address this gap, this review takes a systematic approach. Firstly, it focuses on the crystal structure and the potential binding sites of HSA. Additionally, it provides a comprehensive summary of recent progresses in the field of HBNDSs for various biomedical applications over the past five years, categorized according to the type of therapeutic drugs loaded onto HSA. These categories include small-molecule drugs, inorganic materials and bioactive ingredients. Finally, the review summarizes the characteristics and current application status of HBNDSs in drug delivery, and also discusses the challenges that need to be addressed for the clinical transformation of HSA formulations and offers future perspectives in this field.

Effects of tetramethylpyrazine treatment in a rat model of spinal cord injury: A systematic review and meta-analysis

Spinal cord injury (SCI) is a serious disabling condition that leads to the loss of motor, sensory, and excretory functions, seriously affecting the quality of life of patients and imposing a heavy burden on the patient's family and society. There is currently a lack of effective treatments for SCI. However, a large number of experimental studies have shown beneficial effects of tetramethylpyrazine (TMP). We performed a meta-analysis to systematically evaluate the effects of TMP on neurological and motor function recovery in rats with acute SCI. English (PubMed, Web of Science, and EMbase) and Chinese (CNKI, Wanfang, VIP, and CBM) databases were searched for literature related to TMP treatment in rats with SCI published until October 2022. Two researchers independently read the included studies, extracted the data, and evaluated their quality. A total of 29 studies were included, and a risk of bias assessment revealed that the methodological quality of the included studies was low. The results of the meta-analysis showed that the Basso, Beattie, and Bresnahan (BBB; n = 429, pooled mean difference [MD] = 3.44, 95% confidence interval [CI] = 2.67 to 4.22, p < 0.00001) and inclined plane test (n = 133, pooled MD = 5.60, 95% CI = 3.78 to 7.41, p < 0.00001) scores of rats treated with TMP were significantly higher than those in the control group at 14 days after SCI. TMP treatment also resulted in a significant reduction in malondialdehyde (MDA; n = 128, pooled MD = -2.03, 95% CI = -3.47 to -0.58, p < 0.00001) and increased superoxide dismutase (SOD; n = 128, pooled MD = 5.02, 95% CI = 2.39 to 7.65, p < 0.00001). Subgroup analysis indicated that different doses of TMP did not improve the BBB scale and inclined plane test angles. In conclusion, this review showed that TMP can improve SCI outcomes; however, in view of the limitations of the included studies, larger and high-quality studies are required for verification.

Barrier-penetrating liposome targeted delivery of basic fibroblast growth factor for spinal cord injury repair

Nanoparticle technologies offer a non-invasive means to deliver basic fibroblast growth factor (bFGF) for the treatment of spinal cord injury (SCI). However, the inability of bFGF to accumulate at the injury site and inefficient penetration across the blood-spinal cord barrier (BSCB) remain challenges. The present study describes a dual-targeting liposome (bFGF@Lip-Cp&Rp) with injury lesion targeting and BSCB-penetrating capability to deliver bFGF for SCI treatment. The CAQK peptide (Cp) with injury lesion targeting ability and R₂KC peptide (Rp) with BSCB-penetrating capability were grafted onto the liposomes for a flexible and non-invasive drug delivery systems preparation. Results exhibit that the dual-targeted liposomes could significantly cross the BSCB and accumulate at the injury site. During the early stage of SCI, bFGF@Lip-Cp&Rp promotes repair of BSCB and facilitates M2-polarization of macrophages. Regular delivery of bFGF@Lip-Cp&Rp increase HUVECs tube formation and angiogenesis, ameliorate the microenvironment of lesion site, suppress the neuronal apoptosis and axonal atrophy in SCI rats. Importantly, continuous treatment of bFGF@Lip-Cp&Rp supports the restoration of limb motor function in SCI rats. In summary, this research implies that the injury site-targeting and BSCB-penetrating liposomes could be a promising therapeutic approach for the treatment of SCI.

Tetramethylpyrazine ameliorates acute lung injury by regulating the Rac1/LIMK1 signaling pathway

Acute lung injury (ALI) is a respiratory disorder characterized by severe inflammation of the alveoli and lung parenchyma. Tetramethylpyrazine (TMP), the main active compound in Ligusticum chuanxiong Hort (LC), can protect against lipopolysaccharide (LPS)-induced ALI. Our study aimed to investigate how TMP protects the endothelial cell barrier in pulmonary capillaries. We administered TMP intraperitoneally at different doses and found that acute lung injury in mice was improved, but not in a dose-dependent manner. TMP toxicity was tested in vitro. We observed that LPS-induced cytoskeletal remodeling was inhibited by TMP. Murine ALI was induced as follows: For the 1st hit, LPS (2 mg/kg) was injected intraperitoneally; after 16 h, for the 2nd hit, LPS (4 mg/kg) was instilled intratracheally. The mice in treatment groups had TMP or dexamethasone administered intraperitoneally 30 min prior to the 1st hit and 30 min past the 2nd hit. Mice were euthanized 24 h after the last injecting. We measured protein and mRNA levels using enzyme-linked immunosorbent assay (ELISA) and reverse transcriptase real-time PCR (RT-qPCR), respectively. The ultrastructural analysis was performed with transmission electron microscopy (TEM) and the cytoskeleton was observed by immunofluorescence. Immunohistochemistry and Western blotting were used to detect protein expression in the Rac1/LIMK1/ZO-1/occludin signal pathway. The results showed that TMP treatment decreased inflammatory cell infiltration and alleviated LPS-induced damage in lung tissue. Also, TMP significantly inhibited the Rac1/LIMK1/ZO-1/occludin signaling pathway. Our findings show that using TMP during sepsis can protect the pulmonary microvascular endothelial cell barrier and suppress inflammation. Therefore, TMP may have a promising therapeutic role in preventing acute lung injury from sepsis.

Relationship between the therapeutic potential of various plant-derived bioactive compounds and their related microRNAs in neurological disorders

BACKGROUND

Neurological disorders, such as ischemic stroke, spinal cord injury, neurodegenerative diseases, and glioblastoma often lead to long-term disability and death. MicroRNAs (miRNAs) are small single-stranded non-coding RNAs of approximately 22 nucleotides, known to participate in both normal and pathological development, making them ideal therapeutic targets for clinical intervention. Several recent studies have suggested that plant-derived bioactive compounds (PDBCs) can have anti-atherosclerosis, antioxidant, and anti-inflammatory effects by regulating miRNAs. Thus, miRNAs are novel targets for the action of PDBCs.

PURPOSE

The aim of this review was to evaluate the current status of PDBCs targeted miRNAs by dissecting their development status through a literature review.

METHODS

A manual and electronic search was performed for English articles available from inception up to June 2022 reporting PDBCs and their regulating relationship with miRNAs for the therapeutic potential of neurological disorders. Information was retrieved from scientific databases including PubMed, ScienceDirect, Web of Science, Google Scholar and Chemical Abstracts Services. Keywords used for the search engines were "miRNAs" AND "Plant-derived bioactive compounds" in conjunction with "(native weeds OR alien invasive)" AND "traditional herbal medicine".

RESULTS

A total of 37 articles were retrieved on PDBCs and their related miRNAs in neurological disorders. These PDBCs from traditional herbal medicine may play a therapeutic role in neurological disorders in a variety of mechanisms by regulating the corresponding miRNAs. These mechanisms mainly include inhibiting oxidative stress, anti-neuroinflammation, anti-autophagy, and anti-apoptosis. PDBC are a group of chemically distinct compounds derived from medicinal plants, some of which have therapeutic effects on neurological disorders.

CONCLUSION

The emergence of miRNAs as pathological regulatory factors provides a new direction for the study of bioactive compounds in Traditional Chinese medicine and the elucidating of their epigenetic effects. Elucidating the regulatory relationship between bioactive compounds and miRNAs may help to identify new therapeutic targets and promoting the application of these compounds in precision medicine through their targeted molecular activity.

Nucleic acid nanoassembly-enhanced RNA therapeutics and diagnosis

RNAs are involved in the crucial processes of disease progression and have emerged as powerful therapeutic targets and diagnostic biomarkers. However, efficient delivery of therapeutic RNA to the targeted location and precise detection of RNA markers remains challenging. Recently, more and more attention has been paid to applying nucleic acid nanoassemblies in diagnosing and treating. Due to the flexibility and deformability of nucleic acids, the nanoassemblies could be fabricated with different shapes and structures. With hybridization, nucleic acid nanoassemblies, including DNA and RNA nanostructures, can be applied to enhance RNA therapeutics and diagnosis. This review briefly introduces the construction and properties of different nucleic acid nanoassemblies and their applications for RNA therapy and diagnosis and makes further prospects for their development.

Epigallocatechin-3-gallate selenium nanoparticles for neuroprotection by scavenging reactive oxygen species and reducing inflammation

Purpose: Spinal cord injury (SCI) is a severely crippling injury. Scavenging reactive oxygen species (ROS) and suppressing inflammation to ameliorate secondary injury using biomaterials has turned into a promising strategy for SCI recuperation. Herein, epigallocatechin-3-gallate selenium nanoparticles (EGCG-Se NP) that scavenge ROS and attenuate inflammation were used for neuroprotection in SCI.

Methods: EGCG-Se NP were arranged using a simple redox framework. The size, morphology, and chemical structure of the EGCG-Se NP were characterized. The protective effect of EGCG-Se NP for neuroprotection was examined in cell culture and in an SCI rat model.

Results: EGCG-Se NP could promptly scavenge excess ROS and safeguard PC12 cells against H₂O₂-induced oxidative harm in vitro. After intravenous delivery in SCI rats, EGCG-Se NP significantly improved locomotor capacity and diminished the injury region by safeguarding neurons and myelin sheaths. Component studies showed that the main restorative impact of EGCG-Se NP was due to their ROS-scavenging and anti-inflammatory properties.

Conclusion: This study showed the superior neuroprotective effect of EGCG-Se NP through ROS sequestration and anti-inflammatory capabilities. EGCG-Se NP could be a promising and effective treatment for SCI.

Regulatory mechanisms of tetramethylpyrazine on central nervous system diseases: A review

Central nervous system (CNS) diseases can lead to motor, sensory, speech, cognitive dysfunction, and sometimes even death. These diseases are recognized to cause a substantial socio-economic impact on a global scale. Tetramethylpyrazine (TMP) is one of the main active ingredients extracted from the Chinese herbal medicine Ligusticum striatum DC. (Chuan Xiong). Many in vivo and in vitro studies have demonstrated that TMP has a certain role in the treatment of CNS diseases through inhibiting calcium ion overload and glutamate excitotoxicity, anti-oxidative/nitrification stress, mitigating inflammatory response, anti-apoptosis, protecting the integrity of the blood-brain barrier (BBB) and facilitating synaptic plasticity. In this review, we summarize the roles and mechanisms of action of TMP on ischemic cerebrovascular disease, spinal cord injury, Parkinson’s disease, Alzheimer’s disease, cognitive impairments, migraine, and depression. Our review will provide new insights into the clinical applications of TMP and the development of novel therapeutics.

The immune microenvironment and tissue engineering strategies for spinal cord regeneration

Regeneration of neural tissue is limited following spinal cord injury (SCI). Successful regeneration of injured nerves requires the intrinsic regenerative capability of the neurons and a suitable microenvironment. However, the local microenvironment is damaged, including insufficient intraneural vascularization, prolonged immune responses, overactive immune responses, dysregulated bioenergetic metabolism and terminated bioelectrical conduction. Among them, the immune microenvironment formed by immune cells and cytokines plays a dual role in inflammation and regeneration. Few studies have focused on the role of the immune microenvironment in spinal cord regeneration. Here, we summarize those findings involving various immune cells (neutrophils, monocytes, microglia and T lymphocytes) after SCI. The pathological changes that occur in the local microenvironment and the function of immune cells are described. We also summarize and discuss the current strategies for treating SCI with tissue-engineered biomaterials from the perspective of the immune microenvironment.

Construction of bionanoparticles based on Angelica polysaccharides for the treatment of stroke

Ischemic stroke is an acute and severe neurological disease, resulting in disability and death. The poor drug delivery to cerebral ischemic regions is a key challenge of ischemic stroke treatment. Inspired by the ability of Macrophage membranes to cross the blood-brain barrier, We prepared amphiphilic nanoparticles (AOE@TMP) by linking Angelica polysaccharide (APS) and Ethyl ferulate (EF) using oxalate bond (OL) as the linker arm, with an inner core encapsulated with Tetramethylpyrazine (TMP), and finally using macrophage membrane camouflage (MAOE@TMP). The experimental results show that MAOE@TMP can successfully deliver drugs to the site of brain injury and specifically release it in the microenvironment of the brain injury site, and the three active ingredients in the herb pair could potentiate and significantly reduce the cerebral infarction size.

Combination Therapy Using Nanomaterials and Stem Cells to Treat Spinal Cord Injuries

As a part of the central nervous system, the spinal cord (SC) provides most of the communications between the brain and other parts of the body. Any damage to SC interrupts this communication, leading to serious problems, which may remain for the rest of their life. Due to its significant impact on patients' quality of life and its exorbitant medical costs, SC injury (SCI) is known as one of the most challengeable diseases in the world. Thus, it is critical to introduce highly translatable therapeutic platforms for SCI treatment. So far, different strategies have been introduced, among which utilizing various types of stem cells is one of the most interesting ones. The capability of stem cells to differentiate into several types of cell lines makes them promising candidates for the regeneration of injured tissues. One of the other interesting and novel strategies for SCI treatment is the application of nanomaterials, which could appear as a carrier for therapeutic agents or as a platform for culturing the cells. Combining these two approaches, stem cells and nanomaterials, could provide promising therapeutic strategies for SCI management. Accordingly, in this review we have summarized some of the recent advancements in which the applications of different types of stem cells and nanomaterials, alone and in combination forms, were evaluated for SCI treatment.

Biomaterial-Mediated Factor Delivery for Spinal Cord Injury Treatment

Spinal cord injury (SCI) is an injurious process that begins with immediate physical damage to the spinal cord and associated tissues during an acute traumatic event. However, the tissue damage expands in both intensity and volume in the subsequent subacute phase. At this stage, numerous events exacerbate the pathological condition, and therein lies the main cause of post-traumatic neural degeneration, which then ends with the chronic phase. In recent years, therapeutic interventions addressing different neurodegenerative mechanisms have been proposed, but have met with limited success when translated into clinical settings. The underlying reasons for this are that the pathogenesis of SCI is a continued multifactorial disease, and the treatment of only one factor is not sufficient to curb neural degeneration and resulting paralysis. Recent advances have led to the development of biomaterials aiming to promote in situ combinatorial strategies using drugs/biomolecules to achieve a maximized multitarget approach. This review provides an overview of single and combinatorial regenerative-factor-based treatments as well as potential delivery options to treat SCIs.

Recent Advances in the Role of Nuclear Factor Erythroid-2-Related Factor 2 in Spinal Cord Injury: Regulatory Mechanisms and Therapeutic Options

Nuclear factor erythroid-2-related factor 2 (Nrf2) is a pleiotropic transcription factor, and it has been documented that it can induce defense mechanisms both oxidative stress and inflammatory injury. At present, more and more evidences show that the Nrf2 signaling pathway is a key pharmacological target for the treatment of spinal cord injury (SCI), and activating the Nrf2 signaling pathway can effectively treat the inflammatory injury and oxidative stress after SCI. This article firstly introduces the biological studies of the Nrf2 pathway. Meanwhile, it is more powerful to explain that activating the Nrf2 signaling pathway can effectively treat SCI by deeply exploring the relationship between Nrf2 and oxidative stress, inflammatory injury, and SCI. In addition, several potential drugs for the treatment of SCI by promoting Nrf2 activation and Nrf2-dependent gene expression are reviewed. And some other treatment strategies of SCI by modulating the Nrf2 pathway are also summarized. It will provide new ideas and directions for the treatment of SCI.

Ligustrazine alleviates psoriasis-like inflammation through inhibiting TRAF6/c-JUN/NFκB signaling pathway in keratinocyte

Ligusticum chuanxiong Hort (Ligusticum; Apiaceae) (accepted name, Ligusticum striatum DC, on "The Plant List" for the latest version) is a Chinese herbal medicine (CHM) which mainly distributed in Sichuan Basin, China. Chuanxiong is the dried rhizome of Ligusticum chuanxiong Hort. Ligustrazine, also known as tetramethylpyrazine (TMP), is a main active fraction of chuanxiong. The aim of this study was to clarify the underlying mechanisms by which TMP protect against psoriasis-like inflammation in keratinocytes. Here, we demonstrated that TMP alleviated the severity and PASI scores of IMQ-induced psoriasis-like skin lesion in vivo. For the histopathology level, TMP inhibited the over-proliferation of keratinocytes in the epidermis and the substantial immune cells influx in dermis. For the mechanism of the ability of TMP on regulating inflammation, we confirmed that TMP regulate the TRAF6/c-JUN/NFκB signaling pathway through analyzing the proteomics profiling and verifying the expression of TRAF6, pho-c-Jun, pho-NFκB, so that the downstream psoriasis-relevant genes transcribed by c-JUN or NFκB were down-regulated. Furthermore, we predicted TRAF6 as the potential binding point of TMP. Accordingly, our study demonstrated that TMP regulated psoriasis-like inflammation through inhibiting TRAF6/c-JUN/NFκB signaling pathway in keratinocytes, which potentially provides evidence of the mechanism of TMP in the treatment and prevention of psoriasis.