Loading neural stem cells on hydrogel scaffold improves cell retention rate and promotes functional recovery in traumatic brain injury

3D printing of interferon γ-preconditioned NSC-derived exosomes/collagen/chitosan biological scaffolds for neurological recovery after TBI

The reconstruction of neural function and recovery of chronic damage following traumatic brain injury (TBI) remain significant clinical challenges. Exosomes derived from neural stem cells (NSCs) offer various benefits in TBI treatment. Numerous studies confirmed that appropriate preconditioning methods enhanced the targeted efficacy of exosome therapy. Interferon-gamma (IFN-γ) possesses immunomodulatory capabilities and is widely involved in neurological disorders. In this study, IFN-γ was employed for preconditioning NSCs to enhance the efficacy of exosome (IFN-Exo, IE) for TBI. miRNA sequencing revealed the potential of IFN-Exo in promoting neural differentiation and modulating inflammatory responses. Through low-temperature 3D printing, IFN-Exo was combined with collagen/chitosan (3D-CC-IE) to preserve the biological activity of the exosome. The delivery of exosomes via biomaterial scaffolds benefited the retention and therapeutic potential of exosomes, ensuring that they could exert long-term effects at the injury site. The 3D-CC-IE scaffold exhibited excellent biocompatibility and mechanical properties. Subsequently, 3D-CC-IE scaffold significantly improved impaired motor and cognitive functions after TBI in rat. Histological results showed that 3D-CC-IE scaffold markedly facilitated the reconstruction of damaged neural tissue and promoted endogenous neurogenesis. Further mechanistic validation suggested that IFN-Exo alleviated neuroinflammation by modulating the MAPK/mTOR signaling pathway. In summary, the results of this study indicated that 3D-CC-IE scaffold engaged in long-term pathophysiological processes, fostering neural function recovery after TBI, offering a promising regenerative therapy avenue.

Transplantation of human placental chorionic plate-derived mesenchymal stem cells for repair of neurological damage in neonatal hypoxic-ischemic encephalopathy

JOURNAL/nrgr/04.03/01300535-202409000-00035/figure1/v/2024-01-16T170235Z/r/image-tiff Neonatal hypoxic-ischemic encephalopathy is often associated with permanent cerebral palsy, neurosensory impairments, and cognitive deficits, and there is no effective treatment for complications related to hypoxic-ischemic encephalopathy. The therapeutic potential of human placental chorionic plate-derived mesenchymal stem cells for various diseases has been explored. However, the potential use of human placental chorionic plate-derived mesenchymal stem cells for the treatment of neonatal hypoxic-ischemic encephalopathy has not yet been investigated. In this study, we injected human placental chorionic plate-derived mesenchymal stem cells into the lateral ventricle of a neonatal hypoxic-ischemic encephalopathy rat model and observed significant improvements in both cognitive and motor function. Protein chip analysis showed that interleukin-3 expression was significantly elevated in neonatal hypoxic-ischemic encephalopathy model rats. Following transplantation of human placental chorionic plate-derived mesenchymal stem cells, interleukin-3 expression was downregulated. To further investigate the role of interleukin-3 in neonatal hypoxic-ischemic encephalopathy, we established an in vitro SH-SY5Y cell model of hypoxic-ischemic injury through oxygen-glucose deprivation and silenced interleukin-3 expression using small interfering RNA. We found that the activity and proliferation of SH-SY5Y cells subjected to oxygen-glucose deprivation were further suppressed by interleukin-3 knockdown. Furthermore, interleukin-3 knockout exacerbated neuronal damage and cognitive and motor function impairment in rat models of hypoxic-ischemic encephalopathy. The findings suggest that transplantation of hpcMSCs ameliorated behavioral impairments in a rat model of hypoxic-ischemic encephalopathy, and this effect was mediated by interleukin-3-dependent neurological function.

Injectable and Dynamically Crosslinked Zwitterionic Hydrogels for Anti-Fouling and Tissue Regeneration Applications

A zwitterionic injectable and degradable hydrogel based on hydrazide and aldehyde-functionalized [2-(methacryloyloxy)ethyl] dimethyl-(3-sulfopropyl)ammonium hydroxide (DMAPS) precursor polymers that can address practical in vivo needs is reported. Zwitterion fusion interactions between the zwitterionic precursor polymers create a secondary physically crosslinked network to enable much more rapid gelation than previously reported with other synthetic polymers, facilitating rapid gelation at much lower polymer concentrations or degrees of functionalization than previously accessible in addition to promoting zero swelling and long-term degradation responses and significantly stiffer mechanics than are typically accessed with previously reported low-viscosity precursor gelation systems. The hydrogels maintain the highly anti-fouling properties of conventional zwitterionic hydrogels against proteins, mammalian cells, and bacteria while also promoting anti-fibrotic tissue responses in vivo. Furthermore, the use of the hydrogels for effective delivery and subsequent controlled release of viable cells with tunable profiles both in vitro and in vivo is demonstrated, including the delivery of myoblasts in a mouse skeletal muscle defect model for reducing the time between injury and functional mobility recovery. The combination of the injectability, degradability, and tissue compatibility achieved offers the potential to expand the utility of zwitterionic hydrogels in minimally invasive therapeutic applications.

Linc-NSC affects cell differentiation, apoptosis and proliferation in mouse neural stem cells and embryonic stem cells in vitro and in vivo

BACKGROUND

Stem cell therapy is a promising therapeutic strategy. In a previous study, we evaluated tumorigenicity by the stereotactic transplantation of neural stem cells (NSCs) and embryonic stem cells (ESCs) from experimental mice. Twenty-eight days later, there was no evidence of tumor formation or long-term engraftment in the NSCs transplantation group. In contrast, the transplantation of ESCs caused tumor formation; this was due to their high proliferative capacity. Based on transcriptome sequencing, we found that a long intergenic non-coding RNA (named linc-NSC) with unknown structure and function was expressed at 1100-fold higher levels in NSCs than in ESCs. This finding suggested that linc-NSC is negatively correlated with stem cell pluripotency and tumor development, but positively correlated with neurogenesis. In the present study, we investigated the specific role of linc-NSC in NSCs/ESCs in tumor formation and neurogenesis.

METHODS

Whole transcriptome profiling by RNA sequencing and bioinformatics was used to predict lncRNAs that are widely associated with enhanced tumorigenicity. The expression of linc-NSC was assessed by quantitative real-time PCR. We also performed a number of in vitro methods, including cell proliferation assays, differentiation assays, immunofluorescence assays, flow cytometry, along with in vivo survival and immunofluorescence assays to investigate the impacts of linc-NSC on tumor formation and neurogenesis in NSCs and ESCs.

RESULTS

Following the knockdown of linc-NSC in NSCs, NSCs cultured in vitro and those transplanted into the cortex of mice showed stronger survival ability (P < 0.0001), enhanced proliferation(P < 0.001), and reduced apoptosis (P < 0.05); the opposite results were observed when linc-NSC was overexpressed in ESCs. Furthermore, the overexpression of linc-NSC in ECSs induced enhanced apoptosis (P < 0.001) and differentiation (P < 0.01), inhibited tumorigenesis (P < 0.05) in vivo, and led to a reduction in tumor weight (P < 0.0001).

CONCLUSIONS

Our analyses demonstrated that linc-NSC, a promising gene-edited target, may promote the differentiation of mouse NSCs and inhibit tumorigenesis in mouse ESCs. The knockdown of linc-NSC inhibited the apoptosis in NSCs both in vitro and in vivo, and prevented tumor formation, revealing a new dimension into the effect of lncRNA on low survival NSCs and providing a prospective gene manipulation target prior to transplantation. In parallel, the overexpression of linc-NSC induced apoptosis in ESCs both in vitro and in vivo and attenuated the tumorigenicity of ESCs in vivo, but did not completely prevent tumor formation.

Injectable Hydrogels Based on Hyaluronic Acid and Gelatin Combined with Salvianolic Acid B and Vascular Endothelial Growth Factor for Treatment of Traumatic Brain Injury in Mice

Traumatic brain injury (TBI) leads to structural damage in the brain, and is one of the major causes of disability and death in the world. Herein, we developed a composite injectable hydrogel (HA/Gel) composed of hyaluronic acid (HA) and gelatin (Gel), loaded with vascular endothelial growth factor (VEGF) and salvianolic acid B (SAB) for treatment of TBI. The HA/Gel hydrogels were formed by the coupling of phenol-rich tyramine-modified HA (HA-TA) and tyramine-modified Gel (Gel-TA) catalyzed by horseradish peroxidase (HRP) in the presence of hydrogen peroxide (H2O2). SEM results showed that HA/Gel hydrogel had a porous structure. Rheological test results showed that the hydrogel possessed appropriate rheological properties, and UV spectrophotometry results showed that the hydrogel exhibited excellent SAB release performance. The results of LIVE/DEAD staining, CCK-8 and Phalloidin/DAPI fluorescence staining showed that the HA/Gel hydrogel possessed good cell biocompatibility. Moreover, the hydrogels loaded with SAB and VEGF (HA/Gel/SAB/VEGF) could effectively promote the proliferation of bone marrow mesenchymal stem cells (BMSCs). In addition, the results of H&E staining, CD31 and α-SMA immunofluorescence staining showed that the HA/Gel/SAB/VEGF hydrogel possessed good in vivo biocompatibility and pro-angiogenic ability. Furthermore, immunohistochemical results showed that the injection of HA/Gel/SAB/VEGF hydrogel to the injury site could effectively reduce the volume of defective tissues in traumatic brain injured mice. Our results suggest that the injection of HA/Gel hydrogel loaded with SAB and VEGF might provide a new approach for therapeutic brain tissue repair after traumatic brain injury.

Recent Advances in Alginate-Based Hydrogels for Cell Transplantation Applications

With its exceptional biocompatibility, alginate emerged as a highly promising biomaterial for a large range of applications in regenerative medicine. Whether in the form of microparticles, injectable hydrogels, rigid scaffolds, or bioinks, alginate provides a versatile platform for encapsulating cells and fostering an optimal environment to enhance cell viability. This review aims to highlight recent studies utilizing alginate in diverse formulations for cell transplantation, offering insights into its efficacy in treating various diseases and injuries within the field of regenerative medicine.

Enhancing regenerative medicine: the crucial role of stem cell therapy

Stem cells offer new therapeutic avenues for the repair and replacement of damaged tissues and organs owing to their self-renewal and multipotent differentiation capabilities. In this paper, we conduct a systematic review of the characteristics of various types of stem cells and offer insights into their potential applications in both cellular and cell-free therapies. In addition, we provide a comprehensive summary of the technical routes of stem cell therapy and discuss in detail current challenges, including safety issues and differentiation control. Although some issues remain, stem cell therapy demonstrates excellent potential in the field of regenerative medicine and provides novel tactics and methodologies for managing a wider spectrum of illnesses and traumas.

Silencing of LINC00707 Alleviates Brain Injury by Targeting miR-30a-5p to Regulate Microglia Inflammation and Apoptosis

The role of microglia in traumatic brain injury (TBI) has gained considerable attention. The present study aims to elucidate the potential mechanisms of Long intergenic non-protein coding RNA 707 (LINC00707) in TBI-induced microglia activation and inflammatory factor release. An in vivo model of rat TBI and in vitro microglia model was established using Controlled cortex injury (CCI) and lipopolysaccharide (LPS) stimulation. RT-qPCR to detect LINC00707 levels in rat cerebral cortex or cells. Modified Neurological Impairment Score (mNSS) and Morris Water Maze test was conducted to assess the neurological deficits and cognitive impairment. ELISA analysis of pro-inflammatory factors levels. CCK-8 and flow cytometry for cell viability and apoptosis levels. Dual-luciferase report and RIP assay to validate the targeting relationship between LINC00707 and miR-30a-5p. LINC00707 was elevated in the TBI rat cerebral cortex and LPS-induced microglia, while miR-30a-5p was noticeably decreased (P < 0.05). Increased mNSS, cognitive dysfunction, and brain edema in TBI rats were all prominently reversed by silencing of LINC00707, but this reversal was partially abrogated by decreasing miR-30a-5p (P < 0.05). Inhibition of LINC00707 suppressed the overproduction of inflammatory factors in TBI rats (P < 0.05). LPS decreased microglial cell viability, increased apoptosis, and promoted inflammatory overproduction than control, but the silencing of LINC00707 reversed its effect. Suppression of miR-30a-5p attenuated this reversal (P < 0.05). miR-30a-5p was the target miRNA of LINC00707. All in all, the results suggested that inhibiting LINC00707/miR-30a-5p axis could alleviate the progression of TBI by suppressing the inflammation and apoptosis of microglia cells.

Biomaterials in Traumatic Brain Injury: Perspectives and Challenges

Traumatic brain injury (TBI) is a leading cause of mortality and long-term impairment globally. TBI has a dynamic pathology, encompassing a variety of metabolic and molecular events that occur in two phases: primary and secondary. A forceful external blow to the brain initiates the primary phase, followed by a secondary phase that involves the release of calcium ions (Ca2+) and the initiation of a cascade of inflammatory processes, including mitochondrial dysfunction, a rise in oxidative stress, activation of glial cells, and damage to the blood-brain barrier (BBB), resulting in paracellular leakage. Currently, there are no FDA-approved drugs for TBI, but existing approaches rely on delivering micro- and macromolecular treatments, which are constrained by the BBB, poor retention, off-target toxicity, and the complex pathology of TBI. Therefore, there is a demand for innovative and alternative therapeutics with effective delivery tactics for the diagnosis and treatment of TBI. Tissue engineering, which includes the use of biomaterials, is one such alternative approach. Biomaterials, such as hydrogels, including self-assembling peptides and electrospun nanofibers, can be used alone or in combination with neuronal stem cells to induce neurite outgrowth, the differentiation of human neural stem cells, and nerve gap bridging in TBI. This review examines the inclusion of biomaterials as potential treatments for TBI, including their types, synthesis, and mechanisms of action. This review also discusses the challenges faced by the use of biomaterials in TBI, including the development of biodegradable, biocompatible, and mechanically flexible biomaterials and, if combined with stem cells, the survival rate of the transplanted stem cells. A better understanding of the mechanisms and drawbacks of these novel therapeutic approaches will help to guide the design of future TBI therapies.

Promotion of adipose stem cell transplantation using GelMA hydrogel reinforced by PLCL/ADM short nanofibers

Adipose-derived mesenchymal stem cells (ADSCs) show poor survival after transplantation, limiting their clinical application. In this study, a series of poly(l-lactide-co-ϵ-caprolactone) (PLCL)/acellular dermal matrix (ADM) nanofiber scaffolds with different proportions were prepared by electrospinning. By studying their morphology, hydrophilicity, tensile mechanics, and biocompatibility, PLCL/ADM nanofiber scaffolds with the best composition ratio (PLCL:ADM = 7:3) were selected to prepare short nanofibers. And based on this, injectable gelatin methacryloyl (GelMA) hydrogel loaded with PLCL/ADM short nanofibers (GelMA-Fibers) was constructed as a transplantation vector of ADSCs. ADSCs and GelMA-Fibers were co-cultured, and the optimal loading concentration of PLCL/ADM nanofibers was investigated by cell proliferation assay, live/dead cell staining, and cytoskeleton stainingin vitro. In vivoinvestigations were also performed by H&E staining, Oil red O staining, and TUNEL staining, and the survival and apoptosis rates of ADSCs transplantedin vivowere analyzed. It was demonstrated that GelMA-Fibers could effectively promote the proliferation of ADSCsin vitro. Most importantly, GelMA-Fibers increased the survival rate of ADSCs transplantation and decreased their apoptosis rate within 14 d. In conclusion, the constructed GelMA-Fibers would provide new ideas and options for stem cell tissue engineering and stem cell-based clinical therapies.