Localized delivery of methylprednisolone sodium succinate with polymeric nanoparticles in experimental injured spinal cord model

Targeted-delivery of nanomedicine-enabled methylprednisolone to injured spinal cord promotes neuroprotection and functional recovery after acute spinal cord injury in rats

To date, no therapy has been proven to be efficacious in fully restoring neurological functions after spinal cord injury (SCI). Systemic high-dose methylprednisolone (MP) improves neurological recovery after acute SCI in both animal and human. MP therapy remains controversial due to its modest effect on functional recovery and significant adverse effects. To overcome the limitation of MP therapy, we have developed a N-(2-hydroxypropyl) methacrylamide copolymer-based MP prodrug nanomedicine (Nano-MP) that can selectively deliver MP to the SCI lesion when administered systemically in a rat model of acute SCI. Our in vivo data reveal that Nano-MP is significantly more effective than free MP in attenuating secondary injuries and neuronal apoptosis. Nano-MP is superior to free MP in improving functional recovery after acute SCI in rats. These data support Nano-MP as a promising neurotherapeutic candidate, which may provide potent neuroprotection and accelerate functional recovery with improved safety for patients with acute SCI.

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.

Zeolitic imidazole framework-8 loaded gelatin methacryloyl microneedles: A transdural and controlled-release drug delivery system attenuates neuroinflammation after spinal cord injury

Spinal cord injury (SCI) is a matter of significant clinical concern, often treated through early surgical decompression along with methylprednisolone sodium succinate (MPSS). However, the side effects and the unsatisfactory focal concentration of MPSS have limited its further applications. To address this limitation, herein, a versatile drug delivery system of zeolitic imidazole framework-8 (ZIF-8) and gelatin methacryloyl microneedles (GelMA MNs) was developed for stable, transdural, and controlled sustained release of drugs in SCI. The microneedles were used to create tiny pores in the dura mater, allowing for the direct administration of drugs into the spinal cord. ZIF-8 provided a secondary extended release once they were separated from the microneedles. To attenuate the neuroinflammation, MPSS was selected. Such a combination of ZIF-8 and GelMA MNs was able to prolong the release period of MPSS to five days. The system showed transdural capacity, reduction of M1 polarization, and decrease in NLRP3-positive inflammasome and proinflammatory cytokines. In vivo studies indicated that this novel drug delivery strategy could constrict the inflammatory microenvironment, reduce glial scar formation, and promote neural regeneration. Thus, this versatile drug delivery system provides an up-and-coming alternative for stable, transdural, and controlled sustained release of drugs to those suffering from SCI.

Functional State of the Motor Centers of the Lumbar Spine after Contusion (Th8-Th9) with Application of Methylprednisolone-Copolymer at the Site of Injury

Spinal cord injuries must be treated as soon as possible. Studies of NASCIS protocols have questioned the use of methylprednisolone therapy. This study aimed to evaluate the effect of local delivery of methylprednisolone succinate in combination with a tri-block copolymer in rats with spinal cord injury. The experiments were conducted in accordance with the bioethical guidelines. We evaluated the state of the motor centers below the level of injury by assessing the amplitude of evoked motor responses in the hind limb muscles of rats during epidural stimulation. Kinematic analysis was performed to examine the stepping cycle in each rat. Trajectories of foot movements were plotted to determine the range of limb motion, maximum foot lift height, and lateral deviation of the foot in rats on the 21st day after spinal cord injury. We have shown that the local application of methylprednisolone succinate in combination with block copolymer leads to recovery of center excitability by 21 days after injury. In rats, they recovered weight-supported locomotion, directional control of walking, and balance. The proposed assessment method provides valuable information on gait disturbances following injury and can be utilized to evaluate the quality of therapeutic interventions.

Biomimetic engineered approaches for neural tissue engineering: Spinal cord injury

The healing process for spinal cord injuries is complex and presents many challenges. Current advances in nerve regeneration are based on promising tissue engineering techniques, However, the chances of success depend on better mimicking the extracellular matrix (ECM) of neural tissue and better supporting neurons in a three-dimensional environment. The ECM provides excellent biological conditions, including desirable morphological features, electrical conductivity, and chemical compositions for neuron attachment, proliferation and function. This review outlines the rationale for developing a construct for neuron regrowth in spinal cord injury using appropriate biomaterials and scaffolding techniques.

Worldwide productivity and research trend of publications concerning electroactive materials and spinal cord injury: A bibliometric study

Purpose: We investigated the current state and trends in the area during the previous 10 years using bibliometric approaches to evaluate the global scientific output of research on electroactive materials and spinal cord injury. Methods: Studies on spinal cord injury in electroactive materials that were published between 2012 and 2022 were located using the Web of science (WOS) datebase. The software programs bibliometrix R-package and CiteSpace were used to do quantitative analyses of annual publications, nation, author, institution, journal source, co-cited references, and keywords. The studies were categorized by the research's main points using a qualitative analysis, and publications having more than 10 citations each year. Results: In the final analysis, 1,330 relevant papers or reviews were included. There is an increased tendency in both the average annual citation rate and the number of publications in the discipline. The United States and the University of Toronto are the countries and institutions that have contributed the most to this discipline, respectively. The majority of authors are from the China and United States. Zhang Y is the author with the most published articles and holds the top position in the cited author h-index species. The journal with the highest number of published articles is "Disability and rehabilitation"; the journal is divided into four main areas including physics, materials, chemistry, molecular, and biology. The keyword analysis revealed a shift in research hotspots from schwann cell, fracture, and urinary disorders to carbon-based materials, functional recovery, and surgery. Analysis of qualitative data revealed that the role and mechanism of injectable conductive hydrogels in spinal cord healing after damage is a hot topic of current study, with the mechanism primarily focusing on the inhibition of oxidative stress (Nrf2) and apoptosis (Casepase 3). Conclusion: Our bibliometric analysis indicates that research on electroactive materials for spinal cord injury remains an active field of study. Moreover, contemporary research is concentrated on carbon-based materials, functional rehabilitation, and surgery.

Nanomaterial-assisted theranosis of bone diseases

Bone-related diseases refer to a group of skeletal disorders that are characterized by bone and cartilage destruction. Conventional approaches can regulate bone homeostasis to a certain extent. However, these therapies are still associated with some undesirable problems. Fortunately, recent advances in nanomaterials have provided unprecedented opportunities for diagnosis and therapy of bone-related diseases. This review provides a comprehensive and up-to-date overview of current advanced theranostic nanomaterials in bone-related diseases. First, the potential utility of nanomaterials for biological imaging and biomarker detection is illustrated. Second, nanomaterials serve as therapeutic delivery platforms with special functions for bone homeostasis regulation and cellular modulation are highlighted. Finally, perspectives in this field are offered, including current key bottlenecks and future directions, which may be helpful for exploiting nanomaterials with novel properties and unique functions. This review will provide scientific guidance to enhance the development of advanced nanomaterials for the diagnosis and therapy of bone-related diseases.

Clinical Efficacy of Retroauricular Injection of Methylprednisolone Sodium Succinate in the Treatment of Sudden Deafness with Type 2 Diabetes

Background

The etiology of sudden deafness is still unclear. In recent years, people's life rhythm is getting faster and faster. Fatigue, environment, diet, psychology, and other factors have increased the morbidity rate of sudden deafness and improved the quality of life of patients. And work efficiency is greatly affected.

Aims

A study to investigate the clinical efficacy of postauricular injection of methylprednisolone sodium succinate in the treatment of sudden deafness with type 2 diabetes.

Materials and Methods

Sixty patients with sudden deafness who were treated in our hospital from January 2018 to October 2020 were selected as the subjects of this prospective study and divided into 30 cases each in the comparison group and the observation group according to the random number remainder grouping method. The comparison group was treated conventionally, and the observation group was treated with postauricular injection of methylprednisolone sodium succinate on the basis of the comparison group. Patients in the two groups were observed and compared on the 3rd, 6th, and 9th days after treatment with pure-tone hearing threshold checks and regular monitoring of blood glucose, blood rheology, and other indexes.

Results

On the 7th, 14th, and 30th days after treatment, the pure-tone audiometric thresholds of the two groups were gradually decreased, and the changes in the pure-tone audiometric thresholds in the observation group were greater than those in the control group. After lunch on the 6th day and after lunch on the 9th day, it was lower than that in the control group, and the difference was statistically significant (P < 0.05). 30 days after treatment, the blood viscosity, fibrin, and platelet aggregation rate of the observation group were significantly lower than those of the control group. After treatment, the clinical efficacy rate of the observation group was 96%, which was significantly higher than that of the control group, 80%, and the above differences were statistically significant (P < 0.05).

Conclusion

Treatment with postauricular injection of methylprednisolone sodium succinate has shown better therapeutic recovery in patients with sudden deafness, improved pure-tone hearing threshold, reduced risk of blood glucose elevation, and improved clinical outcomes for patients with sudden deafness, providing some reference for the treatment of patients with sudden deafness.

Reverse Adverse Immune Microenvironments by Biomaterials Enhance the Repair of Spinal Cord Injury

Spinal cord injury (SCI) is a severe and traumatic disorder that ultimately results in the loss of motor, sensory, and autonomic nervous function. After SCI, local immune inflammatory response persists and does not weaken or disappear. The interference of local adverse immune factors after SCI brings great challenges to the repair of SCI. Among them, microglia, macrophages, neutrophils, lymphocytes, astrocytes, and the release of various cytokines, as well as the destruction of the extracellular matrix are mainly involved in the imbalance of the immune microenvironment. Studies have shown that immune remodeling after SCI significantly affects the survival and differentiation of stem cells after transplantation and the prognosis of SCI. Recently, immunological reconstruction strategies based on biomaterials have been widely explored and achieved good results. In this review, we discuss the important factors leading to immune dysfunction after SCI, such as immune cells, cytokines, and the destruction of the extracellular matrix. Additionally, the immunomodulatory strategies based on biomaterials are summarized, and the clinical application prospects of these immune reconstructs are evaluated.

Advancement of nanomedicines in chronic inflammatory disorders

Chronic diseases, as stated by the WHO, are a threat to human health which kill 3 out of every 5 people worldwide. Therapeutics for such illnesses can be developed using traditional medicine. However, it is not an easy path from natural products to Western pharmacological and pharmaceutical methods. For several decades, chronic inflammatory disorders, especially in Westernized countries, have increased incidence and prevalence. Several NSAIDs are used to decrease inflammation and pain; however, there are numerous negative consequences of these anti-inflammatory medications, whereas plant-based natural products have anti-inflammatory therapeutic benefits that have little or no adverse effects. Nanoparticles are a new type of drug delivery device that may be designed to provide excellent target selectivity for certain cells and tissues while also having a high drug loading capacity, resulting in better pharmacokinetics, pharmacodynamics (PKPD), and therapeutic bioavailability. The size and polarity of phytochemical compounds make it hard to pass the blood–brain barrier (BBB), blood-vessel endothelial lining, gastrointestinal tract and mucosa. In addition, the gastrointestinal system is enzymatically destroyed. Therefore, nanoparticles or nanocrystals might also be used for encapsulation or conjugation of these chemicals as a method to improve their organic effectiveness through their gastrointestinal stability, absorption rate and dispersion. The therapy of numerous inflammatory illnesses, including arthritis, gastritis, Nephritis, Hepatitis (Type A, B &C), ulcerative colitis, Alzheimer's disease, atherosclerosis, allergic responses (asthma, eczema) or autoimmune disorders, is characterised by nanoparticles. This review paper provides information on the numerous nanosystem described with their probable mechanism to treat chronic inflammatory diseases.

Therapeutic targets and nanomaterial-based therapies for mitigation of secondary injury after spinal cord injury

Spinal cord injury (SCI) and the resulting neurological trauma commonly result in complete or incomplete neurological dysfunction and there are few effective treatments for primary SCI. However, the following secondary SCI, including the changes of microvasculature, inflammatory response and oxidative stress around the injury site, may provide promising therapeutic targets. The advances of nanomaterials hold promise for delivering therapeutics to alleviate secondary SCI and promote functional recovery. In this review, we highlight recent achievements of nanomaterial-based therapy, specifically targeting blood-spinal cord barrier disruption, mitigation of the inflammatory response and lightening of oxidative stress after spinal cord injury.

Nanoparticles in traumatic spinal cord injury: therapy and diagnosis

Nanotechnology has been previously employed for constructing drug delivery vehicles, biosensors, solar cells, lubricants and as antimicrobial agents. The advancement in synthesis procedure makes it possible to formulate nanoparticles (NPs) with precise control over physico-chemical and optical properties that are desired for specific clinical or biological applications. The surface modification technology has further added impetus to the specific applications of NPs by providing them with desirable characteristics. Hence, nanotechnology is of paramount importance in numerous biomedical and industrial applications due to their biocompatibility and stability even in harsh environments. Traumatic spinal cord injuries (TSCIs) are one of the major traumatic injuries that are commonly associated with severe consequences to the patient that may reach to the point of paralysis. Several processes occurring at a biochemical level which exacerbate the injury may be targeted using nanotechnology. This review discusses possible nanotechnology-based approaches for the diagnosis and therapy of TSCI, which have a bright future in clinical practice.

Comparison of systemic and localized carrier-mediated delivery of methylprednisolone succinate for treatment of acute spinal cord injury

Localized carrier-mediated administration of drugs is a promising approach to treatment of acute phase of spinal cord injury (SCI) as it allows enhanced and/or sustained drug delivery to damaged tissues along with minimization of systemic side effects. We studied the effect of locally applied self-assembling micellar formulation of methylprednisolone succinate (MPS) with trifunctional block copolymer of ethylene oxide and propylene oxide (TBC) on functional recovery and tissue drug content after SCI in rats in comparison with local and systemic administration of MPS alone. Variations in the amplitude of motor evoked responses in the hindlimb muscles induced by epidural stimulation during acute phase of SCI and restoration of movements during chronic period after local vs. systemic application of MPS were evaluated in this study. Results demonstrate that local delivery of MPS in combination with TBC facilitates spinal cord sensorimotor circuitry, increasing the excitability. In addition, this formulation was found to be more effective in improvement of locomotion after SCI compared to systemic administration. LC-MS/MS data shows that the use of TBC carrier increases the glucocorticoid content in treated spinal cord by more than four times over other modes of treatment. The results of this study demonstrate that the local treatment of acute SCI with MPS in the form of mixed micelles with TBC can provide improved therapeutic outcome by promoting drug accumulation and functional restoration of the spinal cord.

Hydrogel-based local drug delivery strategies for spinal cord repair

Spinal cord injury results in significant loss of motor, sensory, and autonomic functions. Although a wide range of therapeutic agents have been shown to attenuate secondary injury or promote regeneration/repair in animal models of spinal cord injury, clinical translation of these strategies has been limited, in part due to difficulty in safely and effectively achieving therapeutic concentrations in the injured spinal cord tissue. Hydrogel-based drug delivery systems offer unique opportunities to locally deliver drugs to the injured spinal cord with sufficient dose and duration, while avoiding deleterious side effects associated with systemic drug administration. Such local drug delivery systems can be readily fabricated from biocompatible and biodegradable materials. In this review, hydrogel-based strategies for local drug delivery to the injured spinal cord are extensively reviewed, and recommendations are made for implementation.

Application of fibrin-based hydrogels for nerve protection and regeneration after spinal cord injury

Traffic accidents, falls, and many other events may cause traumatic spinal cord injuries (SCIs), resulting in nerve cells and extracellular matrix loss in the spinal cord, along with blood loss, inflammation, oxidative stress (OS), and others. The continuous development of neural tissue engineering has attracted increasing attention on the application of fibrin hydrogels in repairing SCIs. Except for excellent biocompatibility, flexibility, and plasticity, fibrin, a component of extracellular matrix (ECM), can be equipped with cells, ECM protein, and various growth factors to promote damage repair. This review will focus on the advantages and disadvantages of fibrin hydrogels from different sources, as well as the various modifications for internal topographical guidance during the polymerization. From the perspective of further improvement of cell function before and after the delivery of stem cell, cytokine, and drug, this review will also evaluate the application of fibrin hydrogels as a carrier to the therapy of nerve repair and regeneration, to mirror the recent development tendency and challenge.

Advanced nanomedicines for the treatment of inflammatory diseases

Inflammation, a common feature of many diseases, is an essential immune response that enables survival and maintains tissue homeostasis. However, in some conditions, the inflammatory process becomes detrimental, contributing to the pathogenesis of a disease. Targeting inflammation by using nanomedicines (i.e. nanoparticles loaded with a therapeutic active principle), either through the recognition of molecules overexpressed onto the surface of activated macrophages or endothelial cells, or through enhanced vasculature permeability, or even through biomimicry, offers a promising solution for the treatment of inflammatory diseases. After providing a brief insight on the pathophysiology of inflammation and current therapeutic strategies, the review will discuss, at a pre-clinical stage, the main innovative nanomedicine approaches that have been proposed in the past five years for the resolution of inflammatory disorders, finally focusing on those currently in clinical trials.

Valproic acid-labeled chitosan nanoparticles promote recovery of neuronal injury after spinal cord injury

Chitosan nanoparticles have been recognized as a new type of biomaterials for treatment of spinal cord injury (SCI). To develop a novel treatment method targeted delivery injured spinal cord, valproic acid labeled chitosan nanoparticles (VA-CN) were constructed and evaluated in the treatment of SCI. Our results demonstrated that administration of VA-CN significantly promoted the recovery of the function and tissue repair after SCI. Moreover, we found treatment of VA-CN inhibited the reactive astrocytes after SCI. Furthermore, administration of VA-CN enhanced immunoreactions of neuronal related marker NF160, which suggested that VA-CN could promote the neuroprotective function in rats of SCI. The production of IL-1β, IL-6 and TNF-α were significantly decreased following treatment of VA-CN. Meanwhile, administration of VA-CN effectively improved the blood spinal cord barrier (BSCB) disruption after SCI. Administration of VA-CN could enhance the recovery of neuronal injury, suppress the reactive astrocytes and inflammation, and improve the blood spinal cord barrier disruption after SCI in rats. These results provided a novel and promising therapeutic manner for SCI.

Compatible stability of methylprednisolone sodium succinate and tropisetron in 0.9% sodium chloride injection

Background

A combination of methylprednisolone sodium succinate and tropisetron hydrochloride is commonly used to treat the nausea and vomiting associated with antineoplastic therapy. The objective of this study was to investigate the stability of tropisetron hydrochloride and methylprednisolone sodium succinate in 0.9% sodium chloride injection for up to 48 hours.

Methods

Commercial solutions of methylprednisolone sodium succinate and tropisetron hydrochloride were obtained and further diluted with 0.9% sodium chloride injection to final concentrations of either 0.4 or 0.8 mg/mL (methylprednisolone sodium succinate) and 0.05 mg/mL (tropisetron). The admixtures were assessed for periods of up to 48 hours after storage at 4°C with protection from light and at 25°C without protection from light. Physical compatibility was determined visually, and the chemical compatibility was measured with high-performance liquid chromatography (HPLC) and by measurement of pH values.

Results

HPLC analysis demonstrated that methylprednisolone sodium succinate and tropisetron hydrochloride in the various solutions were maintained at 97% of the initial concentrations or higher during the testing period. There were no changes observed by physical precipitation or pH in any of the prepared solutions.

Conclusions

Tropisetron hydrochloride injection and methylprednisolone sodium succinate injection in 0.9% sodium chloride injection are stable for up to 48 hours at 4°C and 25°C.

Promising Role of Nano-Encapsulated Drugs for Spinal Cord Injury

Nanomaterials have been utilized for the drug delivery in the central nervous system (CNS), and many research investigators are currently focussing on this specified area. There has been a lot of advancement in the nanoparticle-mediated drug delivery to the brain. Neuronal injuries including spinal cord injury (SCI) and their targeted therapies are still in its infancy on this planet. SCI has been known to cause axonal damage followed by the loss of communication between CNS and other non-neuronal systems. SCI has been critically associated with prolonged inflammation, sensory dysfunction, and motor impairment in SCI patients. There has been a critical crosstalk in SCI and blood brain barriers (BBBs) for drug absorption and distribution in patients. There is a paucity of possible therapies for proper intervention of SCI due to selective permeability of the drugs across BBB. Nanomaterials are contemplated in the drug delivery system for SCI. In addition, self-assembled nanomicelles, lipid nanoparticles, and other co-polymers have now been explored for neuronal injuries. This review focuses on the promising approach and/or role of nanodrug delivery to target SCI in both in vitro and in vivo models.

NEP1-40-modified human serum albumin nanoparticles enhance the therapeutic effect of methylprednisolone against spinal cord injury

Background

Frequent injection of high-dose methylprednisolone (MP) is used to treat spinal cord injury (SCI), but free MP is associated with various side effects and its water solubility is low, limiting potential dosing regimes and administration routes. Albumin-based nanoparticles, which can encapsulate therapeutic drugs and release cargo in a controlled pattern, show high biocompatibility and low toxicity. The Nogo protein, expressed on the surface of oligodendrocytes, can inhibit axonal growth by binding with the axonal Nogo receptor (NgR). Peptide NEP_1-40, an NgR antagonist, can bind specifically to Nogo, significantly improving functional recovery and axon growth in the corticospinal tract. Therefore, we hypothesized that delivering MP within nanoparticles decorated with NEP_1-40 could avoid the disadvantages of free MP and enhance its therapeutic efficacy against SCI.

Results

We used human serum albumin to prepare MP-loaded NPs (MP-NPs), to whose surface we conjugated NEP_1-40 to form NEP_1-40-MP-NPs. Transmission electron microscopy indicated successful formation of nanoparticles. NEP_1-40-MP-NPs were taken up significantly better than MP-NPs by the Nogo-positive cell line RSC-96 and were associated with significantly higher Basso–Beattie–Bresnahan locomotor scores in rats recovering from SCI. Micro-computed tomography assay showed that NEP_1-40-MP-NPs mitigated SCI-associated loss of bone mineral density and accelerated spinal cord repair.

Conclusions

NEP_1-40-MP-NPs can enhance the therapeutic effects of MP against SCI. This novel platform may also be useful for delivering other types of drugs.

Electronic supplementary material

The online version of this article (10.1186/s12951-019-0449-3) contains supplementary material, which is available to authorized users.

Biomaterial strategies for limiting the impact of secondary events following spinal cord injury

The nature of traumatic spinal cord injury (SCI) often involves limited recovery and long-term quality of life complications. The initial injury sets off a variety of secondary cascades, which result in an expanded lesion area. Ultimately, the native tissue fails to regenerate. As treatments are developed in the laboratory, the management of this secondary cascade is an important first step in achieving recovery of normal function. Current literature identifies four broad targets for intervention: inflammation, oxidative stress, disruption of the blood-spinal cord barrier, and formation of an inhibitory glial scar. Because of the complex and interconnected nature of these events, strategies that combine multiple therapies together show much promise. Specifically, approaches that rely on biomaterials to perform a variety of functions are generating intense research interest. In this review, we examine each target and discuss how biomaterials are currently used to address them. Overall, we show that there are an impressive amount of biomaterials and combinatorial treatments which show good promise for slowing secondary events and improving outcomes. If more emphasis is placed on growing our understanding of how materials can manage secondary events, treatments for SCI can be designed in an increasingly rational manner, ultimately improving their potential for translation to the clinic.