Autologous exosome facilitates load and target delivery of bioactive peptides to repair spinal cord injury

ROS-responsive nanoparticle delivery of ferroptosis inhibitor prodrug to facilitate mesenchymal stem cell-mediated spinal cord injury repair

Spinal cord injury (SCI) is a traumatic condition that results in impaired motor and sensory function. Ferroptosis is one of the main causes of neural cell death and loss of neurological function in the spinal cord, and ferroptosis inhibitors are effective in reducing inflammation and repairing SCI. Although human umbilical cord mesenchymal stem cells (Huc-MSCs) can ameliorate inflammatory microenvironments and promote neural regeneration in SCI, their efficacy is greatly limited by the local microenvironment after SCI. Therefore, in this study, we constructed a drug-release nanoparticle system with synergistic Huc-MSCs and ferroptosis inhibitor, in which we anchored Huc-MSCs by a Tz-A6 peptide based on the CD44-targeting sequence, and combined with the reactive oxygen species (ROS)-responsive drug nanocarrier mPEG-b-Lys-BECI-TCO at the other end for SCI repair. Meanwhile, we also modified the classic ferroptosis inhibitor Ferrostatin-1 (Fer-1) and synthesized a new prodrug Feborastatin-1 (Feb-1). The results showed that this treatment regimen significantly inhibited the ferroptosis and inflammatory response after SCI, and promoted the recovery of neurological function in rats with SCI. This study developed a combination therapy for the treatment of SCI and also provides a new strategy for the construction of a drug-coordinated cell therapy system.

Mexican Multicenter Experience of Metastatic Spinal Disease

Background Spinal metastatic disease is a silent progressive cancer complication with an increasing prevalence worldwide. The spine is the third most common site where solid tumors metastasize. Complications involved in spinal metastasis include root or spinal cord compression, progressing to a declining quality of life as patient autonomy reduces and pain increases. The main objective of this study is to report the incidence of patients and typology of spinal metastases in three reference centers in Mexico. Methodology Retrospective cohorts of patients diagnosed with spinal metastases from January 2010 to February 2017 at the National Cancer Institute, National Rehabilitation Institute, and the Traumatology and Orthopedics Hospital "Lomas Verdes" in Mexico City were analyzed. Results A total of 326 patients (56% males) with spinal metastases were reported. The mean age was 58.06 ± 14.05 years. The main sources of spinal metastases were tumors of unknown origin in 53 (16.25%) cases, breast cancer in 67 (20.5%) cases, prostate cancer in 59 (18%) cases, myeloma in 24 (7.4%) cases, and lung cancer in 23 (7.1%) cases. Conclusions The data obtained in this analysis delivers an updated standpoint on Mexico, providing the opportunity to distinguish the current data from global references. Collecting more epidemiological information for better recording of cancer and its associated complications, as well as further studies on them, is necessary.

Dual role of mesenchymal stem/stromal cells and their cell-free extracellular vesicles in colorectal cancer

Colorectal cancer (CRC) is one of the main causes of cancer-related deaths. However, the surgical control of the CRC progression is difficult, and in most cases, the metastasis leads to cancer-related mortality. Mesenchymal stem/stromal cells (MSCs) with potential translational applications in regenerative medicine have been widely researched for several years. MSCs could affect tumor development through secreting exosomes. The beneficial properties of stem cells are attributed to their cell-cell interactions as well as the secretion of paracrine factors in the tissue microenvironment. For several years, exosomes have been used as a cell-free therapy to regulate the fate of tumor cells in a tumor microenvironment. This review discusses the recent advances and current understanding of assessing MSC-derived exosomes for possible cell-free therapy in CRC.

Exosomes derived from CD271+CD56+ bone marrow mesenchymal stem cell subpopoulation identified by single-cell RNA sequencing promote axon regeneration after spinal cord injury

Rationale: Spinal cord injury (SCI) results in neural tissue damage. However, the limited regenerative capacity of adult mammals' axons upon SCI leads to persistent neurological dysfunction. Thus, exploring the pathways that can enhance axon regeneration in injured spinal cord is of great significance. Methods: Through the utilization of single-cell RNA sequencing in this research, a distinct subpopulation of bone marrow mesenchymal stem cells (BMSCs) that exhibits the capacity to facilitate axon regeneration has been discovered. Subsequently, the CD271+CD56+ BMSCs subpopulation was isolated using flow cytometry, and the exosomes derived from this subpopulation (CD271+CD56+ BMSC-Exos) were extracted and incorporated into a hydrogel to create a sustained release system. The aim was to investigate the therapeutic effects of CD271+CD56+ BMSC-Exos and elucidate the underlying mechanisms involved in promoting axon regeneration and neural function recovery. Results: The findings indicate that CD271+CD56+ BMSC-Exos share similar physical and chemical properties with conventional exosomes. Importantly, in an SCI model, in situ implantation of CD271+CD56+ BMSC-Exos hydrogel resulted in increased expression of NF and synaptophysin, markers associated with axon regeneration and synapse formation, respectively. This intervention also contributed to improved neural function recovery. In vitro experiments demonstrated that CD271+CD56+ BMSC-Exos treatment significantly enhanced axon extension distance and increased the number of branches in dorsal root ganglion axons. Moreover, further investigation into the molecular mechanisms underlying CD271+CD56+ BMSC-Exos-mediated axon regeneration revealed the crucial involvement of the miR-431-3p/RGMA axis. Conclusion: In summary, the implantation of CD271+CD56+ BMSC-Exos hydrogel presents a promising and effective therapeutic approach for SCI.

Recovery of Forearm and Fine Digit Function After Chronic Spinal Cord Injury by Simultaneous Blockade of Inhibitory Matrix Chondroitin Sulfate Proteoglycan Production and the Receptor PTPσ

Spinal cord injuries (SCI), for which there are limited effective treatments, result in enduring paralysis and hypoesthesia, in part because of the inhibitory microenvironment that develops and limits regeneration/sprouting, especially during chronic stages. Recently, we discovered that targeted enzymatic removal of the inhibitory chondroitin sulfate proteoglycan (CSPG) component of the extracellular and perineuronal net (PNN) matrix via Chondroitinase ABC (ChABC) rapidly restored robust respiratory function to the previously paralyzed hemi-diaphragm after remarkably long times post-injury (up to 1.5 years) following a cervical level 2 lateral hemi-transection. Importantly, ChABC treatment at cervical level 4 in this chronic model also elicited improvements in gross upper arm function. In the present study, we focused on arm and hand function, seeking to highlight and optimize crude as well as fine motor control of the forearm and digits at lengthy chronic stages post-injury. However, instead of using ChABC, we utilized a novel and more clinically relevant systemic combinatorial treatment strategy designed to simultaneously reduce and overcome inhibitory CSPGs. Following a 3-month upper cervical spinal hemi-lesion using adult female Sprague Dawley rats, we show that the combined treatment had a profound effect on functional recovery of the chronically paralyzed forelimb and paw, as well as on precision movements of the digits. The regenerative and immune system related events that we describe deepen our basic understanding of the crucial role of CSPG-mediated inhibition via the PTPσ receptor in constraining functional synaptic plasticity at lengthy time points following SCI, hopefully leading to clinically relevant translational benefits.

The research landscape of immunology research in spinal cord injury from 2012 to 2022

Background

Spinal cord injury (SCI) is defined as traumatic damage to the spinal cord, affecting over three million patients worldwide, and there is still no treatment for the injured spinal cord itself. In recent years, immunology research on SCI has been published in various journals.

Methods

To systematically analyze the research hotspots and dynamic scientific developments of immunology research in SCI, we conducted a bibliometric and knowledge map analysis to help researchers gain a global perspective in this research field.

Results

The bibliometric study we completed included 1788 English-language papers published in 553 journals by 8861 authors from 1901 institutions in 66 countries/regions. Based on the references and keyword analysis, researchers in the past 10 years have mainly focused on the research directions of "monocyte chemoattractor protein 1," "nitric oxide," "pain," and "nitric oxide synthase" related to immunological research in SCI. However, with the development of other new directions such as "extracellular vesicles" (2019-2022), "Regenerative medicine" (2019-2022), "stromal cells" (2018-2022), "motor recovery" (2019-2022), and "glial activation" (2019-2022). Researchers prefer to study the application of regenerative strategies in SCI, the mechanism of extracellular vesicles in the development of SCI, the activation of spinal glial cells in SCI, and the pathways of motor recovery. This bibliometric analysis of immunology research in SCI summarizes the current status of this research field. The relationship between extracellular vesicles, regenerative medicine, stromal cells, motor recovery, and glial activation is currently a major research frontier. Further research and cooperation worldwide need to be enhanced.

Conclusion

We believe that our research can help researchers quickly grasp the current hotspot of immunology research in SCI and determine a new direction for future research.

Recent advances in lipid nanovesicles for targeted treatment of spinal cord injury

The effective regeneration and functional restoration of damaged spinal cord tissue have been a long-standing concern in regenerative medicine. Treatment of spinal cord injury (SCI) is challenging due to the obstruction of the blood-spinal cord barrier (BSCB), the lack of targeting of drugs, and the complex pathophysiology of injury sites. Lipid nanovesicles, including cell-derived nanovesicles and synthetic lipid nanovesicles, are highly biocompatible and can penetrate BSCB, and are therefore effective delivery systems for targeted treatment of SCI. We summarize the progress of lipid nanovesicles for the targeted treatment of SCI, discuss their advantages and challenges, and provide a perspective on the application of lipid nanovesicles for SCI treatment. Although most of the lipid nanovesicle-based therapy of SCI is still in preclinical studies, this low immunogenicity, low toxicity, and highly engineerable nanovesicles will hold great promise for future spinal cord injury treatments.

The Role of Mesenchymal Stromal Cells and Their Products in the Treatment of Injured Spinal Cords

Spinal cord injury (SCI) is a destructive condition that results in lasting neurological damage resulting in disruption of the connection between the central nervous system and the rest of the body. Currently, there are several approaches in the treatment of a damaged spinal cord; however, none of the methods allow the patient to return to the original full-featured state of life before the injury. Cell transplantation therapies show great potential in the treatment of damaged spinal cords. The most examined type of cells used in SCI research are mesenchymal stromal cells (MSCs). These cells are at the center of interest of scientists because of their unique properties. MSCs regenerate the injured tissue in two ways: (i) they are able to differentiate into some types of cells and so can replace the cells of injured tissue and (ii) they regenerate tissue through their powerful known paracrine effect. This review presents information about SCI and the treatments usually used, aiming at cell therapy using MSCs and their products, among which active biomolecules and extracellular vesicles predominate.