Cell therapy with bone marrow stromal cells after intracerebral hemorrhage: impact of platelet-rich plasma scaffolds

Current Status and Progress in Stem Cell Therapy for Intracerebral Hemorrhage

Intracerebral hemorrhage is a highly prevalent and prognostically poor disease, imposing immeasurable harm on human life and health. However, the treatment options for intracerebral hemorrhage are severely limited, particularly in terms of improving the microenvironment of the lesion, promoting neuronal cell survival, and enhancing neural function. This review comprehensively discussed the application of stem cell therapy for intracerebral hemorrhage, providing a systematic summary of its developmental history, types of transplants, transplantation routes, and transplantation timing. Moreover, this review presented the latest research progress in enhancing the efficacy of stem cell transplantation, including pretransplantation preconditioning, genetic modification, combined therapy, and other diverse strategies. Furthermore, this review pioneeringly elaborated on the barriers to clinical translation for stem cell therapy. These discussions were of significant importance for promoting stem cell therapy for intracerebral hemorrhage, facilitating its clinical translation, and improving patient prognosis.

A new perspective on the regulation of neuroinflammation in intracerebral hemorrhage: mechanisms of NLRP3 inflammasome activation and therapeutic strategies

Intracerebral hemorrhage (ICH), a specific subtype within the spectrum of stroke disorders, is characterized by its high mortality and significant risk of long-term disability. The initiation and progression of neuroinflammation play a central and critical role in the pathophysiology of ICH. The NOD-like receptor family pyrin domain-containing 3 (NLRP3) inflammasome, a protein complex involved in initiating inflammation, is the central focus of this article. Microglia and astrocytes play critical roles in the inflammatory damage process associated with neuroinflammation. The NLRP3 inflammasome is expressed within both types of glial cells, and its activation drives these cells toward a pro-inflammatory phenotype, which exacerbates inflammatory damage in the brain. However, the regulatory relationship between these two cell types remains to be explored. Targeting NLRP3 inflammasomes in microglia or astrocytes may provide an effective approach to mitigate neuroinflammation following ICH. This article first provides an overview of the composition and activation mechanisms of the NLRP3 inflammasome. Subsequently, it summarizes recent research findings on novel signaling pathways that regulate NLRP3 inflammasome activity. Finally, we reviewed recent progress in NLRP3 inflammasome inhibitors, highlighting the clinical translation potential of certain candidates. These inhibitors hold promise as innovative strategies for managing inflammation following ICH.

Stem Cell Therapies for Intracerebral Hemorrhage: Review of Preclinical and Clinical Studies

Despite recent developments in the treatments for ischemic stroke, such as tissue plasminogen activator (t-PA) and thrombectomy, effective therapies for intracerebral hemorrhage (ICH) remain scarce. Stem cell therapies have attracted considerable attention owing to their potential neuro-regenerative ability; preclinical and clinical studies have been conducted to explore strategies for achieving functional recovery following ICH. In this review, we summarize the findings of preclinical studies on stem cell therapies of ICH, with a focus on different animal models, stem cell sources, transplantation methods, and their potential mechanisms of action. We also provide an overview of data from clinical trials to discuss the current status and future perspectives. Understanding the effectiveness and limitations of stem cell therapy and the future prospects could expand the applications of this novel therapeutic approach for ICH.

Therapeutic strategies for intracerebral hemorrhage

Stroke is the second highest cause of death globally, with an increasing incidence in developing countries. Intracerebral hemorrhage (ICH) accounts for 10-15% of all strokes. ICH is associated with poor neurological outcomes and high mortality due to the combination of primary and secondary injury. Fortunately, experimental therapies are available that may improve functional outcomes in patients with ICH. These therapies targeting secondary brain injury have attracted substantial attention in their translational potential. Here, we summarize recent advances in therapeutic strategies and directions for ICH and discuss the barriers and issues that need to be overcome to improve ICH prognosis.

Perspectives on the mechanism of pyroptosis after intracerebral hemorrhage

Intracerebral hemorrhage (ICH) is a highly harmful neurological disorder with high rates of mortality, disability, and recurrence. However, effective therapies are not currently available. Secondary immune injury and cell death are the leading causes of brain injury and a poor prognosis. Pyroptosis is a recently discovered form of programmed cell death that differs from apoptosis and necrosis and is mediated by gasdermin proteins. Pyroptosis is caused by multiple pathways that eventually form pores in the cell membrane, facilitating the release of inflammatory substances and causing the cell to rupture and die. Pyroptosis occurs in neurons, glial cells, and endothelial cells after ICH. Furthermore, pyroptosis causes cell death and releases inflammatory factors such as interleukin (IL)-1β and IL-18, leading to a secondary immune-inflammatory response and further brain damage. The NOD-like receptor protein 3 (NLRP3)/caspase-1/gasdermin D (GSDMD) pathway plays the most critical role in pyroptosis after ICH. Pyroptosis can be inhibited by directly targeting NLRP3 or its upstream molecules, or directly interfering with caspase-1 expression and GSDMD formation, thus significantly improving the prognosis of ICH. The present review discusses key pathological pathways and regulatory mechanisms of pyroptosis after ICH and suggests possible intervention strategies to mitigate pyroptosis and brain dysfunction after ICH.

Efficacy of stem cell therapy in animal models of intracerebral hemorrhage: an updated meta-analysis

BACKGROUND

Multiple studies have reported that stem cell therapy has beneficial effects in animal models of intracerebral hemorrhage (ICH). However, this finding remains inconclusive. This study was performed to systematically determine the effect size of stem cell therapy in ICH animal models by pooling and analyzing data from newly published studies.

METHODS

A literature search identified studies of stem cells in animal models of ICH. We searched mainstream databases from inception to November, 2021. And pooled effect size of stem cells was determined for diversified neurobehavioral scales and structural endpoints using random effects models.

RESULTS

The median quality score of 62 included studies was 5.32. Our results revealed an overall positive effect of stem cell therapy. More specifically, the SMD was - 2.27 for mNSS, - 2.14 for rotarod test, - 2.06 for MLPT, - 1.33 for cylinder test, - 1.95 for corner turn test, - 1.42 for tissue loss, and - 1.86 for brain water content. For mNSS, classifying comparisons by quality score showed significant differences in estimates of effect size (p = 0.013), and high-quality comparisons showed a better outcome (SMD = - 2.57) compared with low-quality comparisons (SMD = - 1.59). Besides, different delivery routes also showed a significant difference in the estimates of effect size for mNSS (p = 0.002), and the intraperitoneal route showed the best outcome (SMD = - 4.63). For tissue loss, the autologous blood-induced ICH model showed a better outcome (SMD = - 1.84) compared with the collagenase-induced ICH model (SMD = - 0.94, p = 0.035). Additionally, stem cell therapy initiated within 8 h post-ICH showed the greatest efficacy on tissue loss reduction, followed by initiated with 24 h post-ICH. Finally, stem cells with different sources and types showed similar beneficial effects for mNSS as well as tissue loss.

CONCLUSIONS

Our results suggested that stem cell therapy had remarkable benefits on ICH animals on both the functional and structural outcomes in animal models of ICH, with very large effect size. These findings support the utility of further studies to translate stem cells in the treatment of ICH in humans. Moreover, the results should be interpreted in the light of the limitations in experimental design and the methodological quality of the studies included in the meta-analysis.

Intracerebral Transplantation of Mesenchymal Stromal Cell Compounded with Recombinant Peptide Scaffold against Chronic Intracerebral Hemorrhage Model

Background

Due to the lack of effective therapies, stem cell transplantation is an anticipated treatment for chronic intracerebral hemorrhage (ICH), and higher cell survival and engraftment are considered to be the key for recovery. Mesenchymal stromal cells (MSCs) compounded with recombinant human collagen type I scaffolds (CellSaics) have a higher potential for cell survival and engraftment compared with solo-MSCs, and we investigated the validity of intracerebral transplantation of CellSaic in a chronic ICH model.

Methods

Rat CellSaics (rCellSaics) were produced by rat bone marrow-derived MSC (rBMSCs). The secretion potential of neurotrophic factors and the cell proliferation rate were compared under oxygen-glucose deprivation (OGD) conditions. rCellSaics, rBMSCs, or saline were transplanted into the hollow cavity of a rat chronic ICH model. Functional and histological analyses were evaluated, and single-photon emission computed tomography for benzodiazepine receptors was performed to monitor sequential changes in neuronal integrity. Furthermore, human CellSaics (hCellSaics) were transplanted into a chronic ICH model in immunodeficient rats. Antibodies neutralizing brain-derived neurotrophic factor (BDNF) were used to elucidate its mode of action.

Results

rCellSaics demonstrated a higher secretion potential of trophic factors and showed better cell proliferation in the OGD condition. Animals receiving rCellSaics displayed better neurological recovery, higher intracerebral BDNF, and better cell engraftment; they also showed a tendency for less brain atrophy and higher benzodiazepine receptor preservation. hCellSaics also promoted significant functional recovery, which was reversed by BDNF neutralization.

Conclusion

Intracerebral transplantation of CellSaics enabled neurological recovery in a chronic ICH model and may be a good option for clinical application.

Application of stem cells and exosomes in the treatment of intracerebral hemorrhage: an update

Non-traumatic intracerebral hemorrhage is a highly destructive intracranial disease with high mortality and morbidity rates. The main risk factors for cerebral hemorrhage include hypertension, amyloidosis, vasculitis, drug abuse, coagulation dysfunction, and genetic factors. Clinically, surviving patients with intracerebral hemorrhage exhibit different degrees of neurological deficits after discharge. In recent years, with the development of regenerative medicine, an increasing number of researchers have begun to pay attention to stem cell and exosome therapy as a new method for the treatment of intracerebral hemorrhage, owing to their intrinsic potential in neuroprotection and neurorestoration. Many animal studies have shown that stem cells can directly or indirectly participate in the treatment of intracerebral hemorrhage through regeneration, differentiation, or secretion. However, considering the uncertainty of its safety and efficacy, clinical studies are still lacking. This article reviews the treatment of intracerebral hemorrhage using stem cells and exosomes from both preclinical and clinical studies and summarizes the possible mechanisms of stem cell therapy. This review aims to provide a reference for future research and new strategies for clinical treatment.

Extracellular vesicles derived from bone marrow mesenchymal stem cells alleviate neuroinflammation after diabetic intracerebral hemorrhage via the miR-183-5p/PDCD4/NLRP3 pathway

OBJECTIVES

Intracerebral hemorrhage (ICH) induced by diabetes results in further brain injury and nerve cell death. Bone marrow mesenchymal stem cell (BMSC) transplantation contributes to attenuating neurological deficits after ICH. This study investigated the mechanism of extracellular vesicles (EVs) derived from BMSCs in reducing neuroinflammation after diabetic ICH.

METHODS

BMSC-EVs were isolated and identified. The rat model of db/db-ICH was established and the model rats were administered with EVs. miR-183-5p expression in brain tissues of db/db-ICH rats was detected. The brain injury of db/db-ICH rats was evaluated by measuring neurobehavioral score, brain water content and inflammatory factors. BV2 cells were cultured in vitro to establish high-glucose (HG)-Hemin-BV2 cell model. The levels of reactive oxygen species (ROS) and inflammatory factors in BV2 cells were measured, and BV2 cell viability and apoptosis were assessed. The targeting relationship between miR-183-5p and PDCD4 was predicted and verified. The activation of PDCD4/NLRP3 pathway in rat brain tissues and BV2 cells was detected.

RESULTS

miR-183-5p expression was reduced in db/db-ICH rats brain tissues. BMSC-EVs ameliorated cranial nerve function, decreased brain water content and repressed inflammatory response by carrying miR-183-5p. BMSC-EVs mitigated HG-Hemin-BV2 cell injury, reduced ROS level and suppressed inflammatory response. miR-183-5p targeted PDCD4. PDCD4 promoted BV2 cell inflammation by activating the NLRP3 pathway. BMSC-EVs inhibited HG-Hemin-BV2 cell inflammation through the miR-183-5p/PDCD4/NLRP3 pathway, and inhibition of miR-183-5p reversed the protective effect of EVs.

CONCLUSION

BMSC-EVs carried miR-183-5p into db/db-ICH rat brain tissues and repressed the NLRP3 pathway by targeting PDCD4, thus alleviating neuroinflammation after diabetic ICH.

Mechanism of White Matter Injury and Promising Therapeutic Strategies of MSCs After Intracerebral Hemorrhage

Intracerebral hemorrhage (ICH) is the most fatal subtype of stroke with high disability and high mortality rates, and there is no effective treatment. The predilection site of ICH is in the area of the basal ganglia and internal capsule (IC), where exist abundant white matter (WM) fiber tracts, such as the corticospinal tract (CST) in the IC. Proximal or distal white matter injury (WMI) caused by intracerebral parenchymal hemorrhage is closely associated with poor prognosis after ICH, especially motor and sensory dysfunction. The pathophysiological mechanisms involved in WMI are quite complex and still far from clear. In recent years, the neuroprotection and repairment capacity of mesenchymal stem cells (MSCs) has been widely investigated after ICH. MSCs exert many unique biological effects, including self-recovery by producing growth factors and cytokines, regenerative repair, immunomodulation, and neuroprotection against oxidative stress, providing a promising cellular therapeutic approach for the treatment of WMI. Taken together, our goal is to discuss the characteristics of WMI following ICH, including the mechanism and potential promising therapeutic targets of MSCs, aiming at providing new clues for future therapeutic strategies.

Mesenchymal Stem Cells Transplantation in Intracerebral Hemorrhage: Application and Challenges

Intracerebral hemorrhage (ICH) is one of the leading causes of death and long-term disability worldwide. Mesenchymal stem cell (MSC) therapies have demonstrated improved outcomes for treating ICH-induced neuronal defects, and the neural network reconstruction and neurological function recovery were enhanced in rodent ICH models through the mechanisms of neurogenesis, angiogenesis, anti-inflammation, and anti-apoptosis. However, many key issues associated with the survival, differentiation, and safety of grafted MSCs after ICH remain to be resolved, which hinder the clinical translation of MSC therapy. Herein, we reviewed an overview of the research status of MSC transplantation after ICH in different species including rodents, swine, monkey, and human, and the challenges for MSC-mediated ICH recovery from pathological microenvironment have been summarized. Furthermore, some efficient strategies for the outcome improvement of MSC transplantation were proposed.

Application of platelet-rich plasma (PRP) improves self-renewal of human spermatogonial stem cells in two-dimensional and three-dimensional culture systems

Spermatogonial stem cells (SSCs) are very sensitive to chemotherapy and radiotherapy, so male infertility is a great challenge for prepubertal cancer survivors. Cryoconservation of testicular cells before cancer treatment can preserve SSCs from treatment side effects. Different two-dimensional (2D) and three-dimensional (3D) culture systems of SSCs have been used in many species as a useful technique to in vitro spermatogenesis. We evaluated the proliferation of SSCs in 2D and 3D culture systems of platelet-rich plasma (PRP). testicular cells of four brain-dead patients cultivated in 2D pre-culture system, characterization of SSCs performed by RT-PCR, flow cytometry, immunocytochemistry and their functionality assessed by xenotransplantation to azoospermia mice. PRP prepared and dosimetry carried out to determine the optimized dose of PRP. After preparation of PRP scaffold, cytotoxic and histological evaluation performed and SSCs cultivated into three groups: control, 2D culture by optimized dose of PRP and PRP scaffold. The diameter and number of colonies measured and relative expression of GFRa1 and c-KIT evaluated by real-time PCR. Results indicated the expression of PLZF, VASA, OCT4, GFRa1 and vimentin in colonies after 2D pre-culture, xenotransplantation demonstrated proliferated SSCs have proper functionality to homing in mouse testes. The relative expression of c-KIT showed a significant increase as compared to the control group (*: p < 0.05) in PRP- 2D group, expression of GFRa1 and c-KIT in PRP scaffold group revealed a significant increase as compared to other groups (***: p < 0.001). The number and diameter of colonies in the PRP-2D group showed a considerable increase (p < 0.01) as compared to the control group. In PRP- scaffold group, a significant increase (p < 0.01) was seen only in the number of colonies related to the control group. Our results suggested that PRP scaffold can reconstruct a suitable structure to the in vitro proliferation of SSCs.

Stroke treatment: Is exosome therapy superior to stem cell therapy?

Stroke is one of the most common causes of disability and death, and currently, ideal clinical treatment is lacking. Stem cell transplantation is a widely-used treatment approach for stroke. When compared with other types of stem cells, bone marrow mesenchymal stem cells (BMSCs) have been widely studied because of their many advantages. The paracrine effect is the primary mechanism for stem cells to play their role, and exosomes play an essential role in the paracrine effect. When compared with cell therapy, cell-free exosome therapy can prevent many risks and difficulties, and therefore, represents a promising and novel approach for treatment. In this study, we reviewed the research progress in the application of BMSCs-derived exosomes (BMSCs-exos) and BMSCs in the treatment of stroke. In addition, the advantages and disadvantages of cell therapy and cell-free exosome therapy were described, and the possible factors that hinder the introduction of these two treatments into the clinic were analyzed. Furthermore, we reviewed the current optimization methods of cell therapy and cell-free exosome therapy. Taken together, we hypothesize that cell-free exosome therapy will have excellent research prospects in the future, and therefore, it is worth further exploring. There are still some issues that need to be further addressed. For example, differences between the in vivo microenvironment and in vitro culture conditions will affect the paracrine effect of stem cells. Most importantly, we believe that more preclinical and clinical design studies are required to compare the efficacy of stem cells and exosomes.

Fibrin Scaffold Incorporating Platelet Lysate Enhance Follicle Survival and Angiogenesis in Cryopreserved Preantral Follicle Transplantation

Background:

Transplantation of cryopreserved follicles can be regarded as a promising strategy for preserving fertility in cancer patients under chemotherapy and radiotherapy by reducing the risk of cancer recurrence. The present study aimed to evaluate whether fibrin hydrogel supplemented with platelet lysate (PL) could be applied to enhance follicular survival, growth, and angiogenesis in cryopreserved preantral follicle grafts.

Materials and Methods:

Preantral follicles were extracted from 15 four-week-old NMRI mice, cryopreserved by cryotop method, and encapsulated in fibrin-platelet lysate for subsequent heterotopic (subcutaneous) auto-transplantation into the neck. Transplants were assessed in three groups including fresh follicles in fibrin-15%PL, cryopreserved follicles in fibrin-15%PL, and cryopreserved follicles in fibrin-0% PL. Two weeks after transplantation, histological, and immunohistochemistry (CD31) analysis were applied to evaluate follicle morphology, survival rate, and vascular formation, respectively.

Results:

Based on the results, fibrin-15% PL significantly increased neovascularization and survival rate (SR) both in cryopreserved (SR=66.96%) and fresh follicle (SR=90.8%) grafts, compared to PL-less fibrin cryopreserved transplants (SR=28.46%). The grafts supplemented with PL included a significantly higher percentage of preantral and antral follicles. Also, no significant difference was observed in the percentage of preantral follicles between cryopreserved and fresh grafts of fibrin-15% PL. However, a significantly lower (P=0.03) percentage of follicles (23.37%) increased to the antral stage in cryopreserved grafts of fibrin-15%PL, compared to fresh grafts (35.01%).

Conclusion:

The findings demonstrated that fibrin-PL matrix could be a promising strategy to improve cryopreserved follicle transplantation and preserve fertility in cancer patients at the risk of ovarian failure.

Application of Stem Cells in Stroke: A Multifactorial Approach

Stroke has a debilitating effect on the human body and a serious negative effect on society, with a global incidence of one in every six people. According to the World Health Organization, 15 million people suffer stroke worldwide each year. Of these, 5 million die and another 5 million are permanently disabled. Motor and cognitive deficits like hemiparesis, paralysis, chronic pain, and psychomotor and behavioral symptoms can persist long term and prevent the patient from fully reintegrating into society, therefore continuing to add to the costly healthcare burden of stroke. Regenerative medicine using stem cells seems to be a panacea for sequelae after stroke. Stem cell-based therapy aids neuro-regeneration and neuroprotection for neurological recovery in patients. However, the use of stem cells as a therapy in stroke patients still needs a lot of research at both basic and translational levels. As well as the mode of action of stem cells in reversing the symptoms not being clear, there are several clinical parameters that need to be addressed before establishing stem cell therapy in stroke, such as the type of stem cells to be administered, the number of stem cells, the timing of dosage, whether dose-boosters are required, the route of administration, etc. There are upcoming prospects of cell-free therapy also by using exosomes derived from stem cells. There are several ongoing pre-clinical studies aiming to answer these questions. Despite still being in the development stage, stem cell therapy holds great potential for neurological rehabilitation in patients suffering from stroke.

Revisiting the Regenerative Therapeutic Advances Towards Erectile Dysfunction

Erectile dysfunction (ED) is an inability to attain or maintain adequate penile erection for successful vaginal intercourse, leading to sexual and relationship dissatisfaction. To combat ED, various surgical and non-surgical approaches have been developed in the past to restore erectile functions. These therapeutic interventions exhibit significant impact in providing relief to patients; however, due to their associated adverse effects and lack of long-term efficacy, newer modalities such as regenerative therapeutics have gained attention due to their safe and prolonged efficacy. Stem cells and platelet-derived biomaterials contained in platelet-rich plasma (PRP) are thriving as some of the major therapeutic regenerative agents. In recent years, various preclinical and clinical studies have evaluated the individual, as well as combined of stem cells and PRP to restore erectile function. Being rich in growth factors, chemokines, and angiogenic factors, both stem cells and PRP play a crucial role in regenerating nerve cells, myelination of axons, homing and migration of progenitor cells, and anti-fibrosis and anti-apoptosis of damaged cavernous nerve in corporal tissues. Further, platelet-derived biomaterials have been proven to be a biological supplement for enhancing the proliferative and differentiation potential of stem cells towards neurogenic fate. Therefore, this article comprehensively analyzes the progresses of these regenerative therapies for ED.

White matter repair and treatment strategy after intracerebral hemorrhage

The predilection site of intracerebral hemorrhage (ICH) is in the basal ganglia, which is rich in white matter (WM) fiber bundles, such as cerebrospinal tract in the internal capsule. ICH induced damage to this area can easily lead to severe neurological dysfunction and affects the prognosis and quality of life of patients. At present, the pathophysiological mechanisms of white matter injury (WMI) after ICH have attracted researchers' attention, but studies on the repair and recovery mechanisms and therapy strategies remain rare. In this review, we mainly summarized the WM recovery and treatment strategies after ICH by updating the WMI-related content by reviewing the latest researches and proposing the bottleneck of the current research.

Adult Stem Cells and Induced Pluripotent Stem Cells for Stroke Treatment

Stroke is the main cause of disability and death in the world within neurological diseases. Despite such a huge impact, enzymatic, and mechanical recanalization are the only treatments available so far for ischemic stroke, but only <20% of patients can benefit from them. The use of stem cells as a possible cell therapy in stroke has been tested for years. The results obtained from these studies, although conflicting or controversial in some aspects, are promising. In the last few years, the recent development of the induced pluripotent stem cells has opened new possibilities to find new cell therapies against stroke. In this review, we will provide an overview of the state of the art of cell therapy in stroke. We will describe the current situation of the most employed stem cells and the use of induced pluripotent stem cells in stroke pathology. We will also present a summary of the different clinical trials that are being carried out or that already have results on the use of stem cells as a potential therapeutic intervention for stroke.

The Potential of Biomaterial-Based Approaches as Therapies for Ischemic Stroke: A Systematic Review and Meta-Analysis of Pre-clinical Studies

Background: In recent years pre-clinical stroke research has shown increased interest in the development of biomaterial-based therapies to promote tissue repair and functional recovery. Such strategies utilize biomaterials as structural support for tissue regeneration or as delivery vehicles for therapeutic agents. While a range of biomaterials have been tested in stroke models, currently no overview is available for evaluating the benefit of these approaches. We therefore performed a systematic review and meta-analysis of studies investigating the use of biomaterials for the treatment of stroke in experimental animal models. Methods: Studies were identified by searching electronic databases (PubMed, Web of Science) and reference lists of relevant review articles. Studies reporting lesion volume and/or neurological score were included. Standardized mean difference (SMD) and 95% confidence intervals were calculated using DerSimonian and Laird random effects. Study quality and risk of bias was assessed using the CAMARADES checklist. Publication bias was visualized by funnel plots followed by trim and fill analysis of missing publications. Results: A total of 66 publications were included in the systematic review, of which 44 (86 comparisons) were assessed in the meta-analysis. Overall, biomaterial-based interventions improved both lesion volume (SMD: -2.98, 95% CI: -3.48, -2.48) and neurological score (SMD: -2.3, 95% CI: -2.85, -1.76). The median score on the CAMARADES checklist was 5.5/10 (IQR 4.25-6). Funnel plots of lesion volume and neurological score data revealed pronounced asymmetry and publication bias. Additionally, trim and fill analysis estimated 19 "missing" studies for the lesion volume outcome adjusting the effect size to -1.91 (95% CI: -2.44, -1.38). Conclusions: Biomaterials including scaffolds and particles exerted a positive effect on histological and neurological outcomes in pre-clinical stroke models. However, heterogeneity in the field, publication bias and study quality scores which may be another source of bias call for standardization of outcome measures and improved study reporting.

PEGylated Platelet-Free Blood Plasma-Based Hydrogels for Full-Thickness Wound Regeneration

Objective: To develop a cost-effective and clinically usable therapy to treat full-thickness skin injuries. We accomplished this by preparing a viscoelastic hydrogel using polyethylene glycol (PEG)-modified platelet-free plasma (PEGylated PFP) combined with human adipose-derived stem cells (ASCs). Approach: PEGylated PFP hydrogels were prepared by polymerizing the liquid mixture of PEG and PFP±ASCs and gelled either by adding calcium chloride (CaCl₂) or thrombin. Rheological and in vitro studies were performed to assess viscoelasticity and the ability of hydrogels to direct ASCs toward a vasculogenic phenotype, respectively. Finally, a pilot study evaluated the efficacy of hydrogels±ASCs using an athymic rat full-thickness skin wound model. Results: Hydrogels prepared within the range of 11 to 27 mM for CaCl₂ or 5 to 12.5 U/mL for thrombin exhibited a storage modulus of ∼62 to 87 Pa and ∼47 to 92 Pa, respectively. The PEGylated PFP hydrogels directed ASCs to form network-like structures resembling vasculature, with a fourfold increase in perivascular specific genes that were confirmed by immunofluorescent staining. Hydrogels combined with ASCs exhibited an increase in blood vessel density when applied to excisional rat wounds compared with those treated with hydrogels (110.3 vs. 95.6 BV/mm²; p < 0.05). Furthermore, ASCs were identified in the perivascular region associated with newly forming blood vessels. Innovation: This study demonstrates that PFP modified with PEG along with ASCs can be used to prepare cost-effective stable hydrogels, at the bed-side, to treat extensive skin wounds. Conclusion: These results indicate that PEGylated plasma-based hydrogels combined with ASCs may be a potential regenerative therapy for full-thickness skin wounds.

Mesenchymal stem cells for hemorrhagic stroke: status of preclinical and clinical research

Significant progress has been made during the past few decades in stem cell therapy research for various diseases and injury states; however this has not been overwhelmingly translated into approved therapies, despite much public attention and the rise in unregulated 'regenerative clinics'. In the last decade, preclinical research focusing on mesenchymal stem/stromal cell (MSC) therapy in experimental animal models of hemorrhagic stroke has gained momentum and has led to the development of a small number of human trials. Here we review the current studies focusing on MSC therapy for hemorrhagic stroke in an effort to summarize the status of preclinical and clinical research. Preliminary evidence indicates that MSCs are both safe and tolerable in patients, however future randomized controlled trials are required to translate the promising preclinical research into an effective therapy for hopeful patients.

Differentiation of Bone Marrow Mesenchymal Stem Cells into Neural Lineage Cells Induced by bFGF-Chitosan Controlled Release System

Bone marrow mesenchymal stem cells undergo differentiation to different lineages with different efficiencies when induced by different factors. We added a bFGF-chitosan controlled release system (bFGF-CCRS) as an inducer into conditioned medium to facilitate the oriented differentiation of BMSCs into neural lineage cells (eventually mature neurons); furthermore, we synchronized BMSCs to the G0/G1 phase via serum starvation to observe the effect of the inducer on the differentiation direction and efficiency. The nonsynchronized group, chitosan alone (not loaded with bFGF) group, soluble bFGF group, and conditioned medium group served as controls, and we observed the dynamic process of differentiation of BMSCs into neural lineage cells at different time points after the beginning of coculture. We analyzed the binding patterns of bFGF and chitosan and assayed the expression differences of key factors (FGFR1, ERK, and c-fos) and molecular switches (BTG2) that regulate the transformation from cell proliferation to differentiation. We also investigated the potential molecular mechanism of BMSC differentiation into neural lineage cells at a high percentage when induced by bFGF-CCRS.

Stem Cell Therapy: A Promising Therapeutic Method for Intracerebral Hemorrhage

Spontaneous intracerebral hemorrhage (ICH) is one type of the most devastating cerebrovascular diseases worldwide, which causes high morbidity and mortality. However, efficient treatment is still lacking. Stem cell therapy has shown good neuroprotective and neurorestorative effect in ICH and is a promising treatment. In this study, our aim was to review the therapeutic effects, strategies, related mechanisms and safety issues of various types of stem cell for ICH treatment. Numerous studies had demonstrated the therapeutic effects of diverse stem cell types in ICH. The potential mechanisms include tissue repair and replacement, neurotrophy, promotion of neurogenesis and angiogenesis, anti-apoptosis, immunoregulation and anti-inflammation and so forth. The microenvironment of the central nervous system (CNS) can also influence the effects of stem cell therapy. The detailed therapeutic strategies for ICH treatment such as cell type, the number of cells, time window, and the routes of medication delivery, varied greatly among different studies and had not been determined. Moreover, the safety issues of stem cell therapy for ICH should not be ignored. Stem cell therapy showed good therapeutic effect in ICH, making it a promising treatment. However, safety should be carefully evaluated, and more clinical trials are required before stem cell therapy can be extensively applied to clinical use.

Platelet-rich plasma therapy and reproductive medicine

Reports on clinical uses of platelet-rich plasma (PRP) have dramatically increased in the last decade. Indications for PRP therapy range from muscle and skeletal injuries to hair re-growth. More recently evidences have shown its positive effects in promoting endometrial and follicular growth and gestation in assisted reproduction cycles. We discuss the putative role of PRP on endometrial receptivity, with a brief history of its applications in research and clinical therapies. Despite its widespread uses in medicine, the mechanisms through which PRP exerts its regenerative effects are only postulated, not based on scientific data. There is an unmet need for advanced research to corroborate present findings in the clinical scenario.

Platelet-rich plasma-derived scaffolds increase the benefit of delayed mesenchymal stromal cell therapy after severe traumatic brain injury

BACKGROUND

Cell therapy using mesenchymal stromal cells (MSCs) offers new perspectives in the treatment of traumatic brain injury (TBI). The aim of the present study was to assess the impact of platelet-rich plasma scaffolds (PRPS) as support of MSCs in a delayed phase after severe TBI in rats.

METHODS

TBI was produced by weight-drop impact to the right cerebral hemisphere. Two months after TBI, four experimental groups were established; saline, PRPS, MSCs in saline, or MSCs in PRPS was transplanted into the area of brain lesion through a small hole. All groups were evaluated in the course of the following 12 months after therapy and the animals were then humanely killed.

RESULTS

Our results showed that a greater functional improvement was obtained after the administration of MSCs in PRPS compared with the other experimental groups.

DISCUSSION

PRPS enhanced the benefit of cell therapy with MSCs to treat chronic brain damage in rats that suffered a severe TBI. The present findings suggest that the use of intralesional MSCs supported in PRPS may be a strategy of tissue engineering for patients with established neurological severe dysfunction after a TBI.

Therapeutic Benefits of Mesenchymal Stromal Cells in a Rat Model of Hemoglobin-Induced Hypertensive Intracerebral Hemorrhage

Previous studies have shown that bone marrow mesenchymal stromal cell (MSC) transplantation significantly improves the recovery of neurological function in a rat model of intracerebral hemorrhage. Potential repair mechanisms involve anti-inflammation, anti-apoptosis and angiogenesis. However, few studies have focused on the effects of MSCs on inducible nitric oxide synthase (iNOS) expression and subsequent peroxynitrite formation after hypertensive intracerebral hemorrhage (HICH). In this study, MSCs were transplanted intracerebrally into rats 6 hours after HICH. The modified neurological severity score and the modified limb placing test were used to measure behavioral outcomes. Blood-brain barrier disruption and neuronal loss were measured by zonula occludens-1 (ZO-1) and neuronal nucleus (NeuN) expression, respectively. Concomitant edema formation was evaluated by H&E staining and brain water content. The effect of MSCs treatment on neuroinflammation was analyzed by immunohistochemical analysis or polymerase chain reaction of CD68, Iba1, iNOS expression and subsequent peroxynitrite formation, and by an enzyme-linked immunosorbent assay of pro-inflammatory factors (IL-1β and TNF-α). The MSCs-treated HICH group showed better performance on behavioral scores and lower brain water content compared to controls. Moreover, the MSC injection increased NeuN and ZO-1 expression measured by immunochemistry/immunofluorescence. Furthermore, MSCs reduced not only levels of CD68, Iba1 and pro-inflammatory factors, but it also inhibited iNOS expression and peroxynitrite formation in perihematomal regions. The results suggest that intracerebral administration of MSCs accelerates neurological function recovery in HICH rats. This may result from the ability of MSCs to suppress inflammation, at least in part, by inhibiting iNOS expression and subsequent peroxynitrite formation.

Platelet-rich plasma, an adjuvant biological therapy to assist peripheral nerve repair

Therapies such as direct tension-free microsurgical repair or transplantation of a nerve autograft, are nowadays used to treat traumatic peripheral nerve injuries (PNI), focused on the enhancement of the intrinsic regenerative potential of injured axons. However, these therapies fail to recreate the suitable cellular and molecular microenvironment of peripheral nerve repair and in some cases, the functional recovery of nerve injuries is incomplete. Thus, new biomedical engineering strategies based on tissue engineering approaches through molecular intervention and scaffolding offer promising outcomes on the field. In this sense, evidence is accumulating in both, preclinical and clinical settings, indicating that platelet-rich plasma products, and fibrin scaffold obtained from this technology, hold an important therapeutic potential as a neuroprotective, neurogenic and neuroinflammatory therapeutic modulator system, as well as enhancing the sensory and motor functional nerve muscle unit recovery.

Microarray expression profiles of genes in lung tissues of rats subjected to focal cerebral ischemia-induced lung injury following bone marrow-derived mesenchymal stem cell transplantation

Ischemia-induced stroke is the most common disease of the nervous system and is associated with a high mortality rate worldwide. Cerebral ischemia may lead to remote organ dysfunction, particular in the lungs, resulting in lung injury. Nowadays, bone marrow-derived mesenchymal stem cells (BMSCs) are widely studied in clinical trials as they may provide an effective solution to the treatment of neurological and cardiac diseases; however, the underlying molecular mechanisms remain unknown. In this study, a model of permanent focal cerebral ischemia-induced lung injury was successfully established and confirmed by neurological evaluation and lung injury scores. We demonstrated that the transplantation of BMSCs (passage 3) via the tail vein into the lung tissues attenuated lung injury. In order to elucidate the underlying molecular mechanisms, we analyzed the gene expression profiles in lung tissues from the rats with focal cerebral ischemia and transplanted with BMSCs using a Gene microarray. Moreover, the Gene Ontology database was employed to determine gene function. We found that the phosphoinositide 3-kinase (PI3K)-AKT signaling pathway, transforming growth factor-β (TGF-β) and platelet-derived growth factor (PDGF) were downregulated in the BMSC transplantation groups, compared with the control group. These results suggested that BMSC transplantation may attenuate lung injury following focal cerebral ischemia and that this effect is associated with the downregulation of TGF-β, PDGF and the PI3K-AKT pathway.

Review of Preclinical and Clinical Studies of Bone Marrow-Derived Cell Therapies for Intracerebral Hemorrhage

Stroke is the second leading cause of mortality worldwide, causing millions of deaths annually, and is also a major cause of disability-adjusted life years. Hemorrhagic stroke accounts for approximately 10 to 27% of all cases and has a fatality rate of about 50% in the first 30 days, with limited treatment possibilities. In the past two decades, the therapeutic potential of bone marrow-derived cells (particularly mesenchymal stem cells and mononuclear cells) has been intensively investigated in preclinical models of different neurological diseases, including models of intracerebral hemorrhage and subarachnoid hemorrhage. More recently, clinical studies, most of them small, unblinded, and nonrandomized, have suggested that the therapy with bone marrow-derived cells is safe and feasible in patients with ischemic or hemorrhagic stroke. This review discusses the available evidence on the use of bone marrow-derived cells to treat hemorrhagic strokes. Distinctive properties of animal studies are analyzed, including study design, cell dose, administration route, therapeutic time window, and possible mechanisms of action. Furthermore, clinical trials are also reviewed and discussed, with the objective of improving future studies in the field.

Stem Cell Therapy and Administration Routes After Stroke

Cell-based therapy has demonstrated safety and efficacy in experimental animal models of stroke, as well as safety in stroke patients. However, various questions remain regarding the therapeutic window, dosage, route of administration, and the most appropriate cell type and source, as well as mechanisms of action and immune-modulation to optimize treatment based on stem cell therapy. Various delivery routes have been used in experimental stroke models, including intracerebral, intraventricular, subarachnoid, intra-arterial, intraperitoneal, intravenous, and intranasal routes. From a clinical point of view, it is necessary to demonstrate which is the most feasible, safest, and most effective for use with stroke patients. Therefore, further experimental studies concerning the safety, efficacy, and mechanisms of action involved in these therapeutic effects are required to determine their optimal clinical use.

Stem cell-based therapies for intracerebral hemorrhage in animal model: a meta-analysis

Stem cell to be a new intervention for treating intracerebral hemorrhage (ICH) might benefit humans. Therefore, we collected animal studies to find the effect of this innovative treatment. In July 2014, we searched Medline (from 1950), Embase (from 1980), China Biology Medicine disk (from 1978) for studies on stem cells used for treating experimental ICH in animal models that reported neurobehavioral and structural outcome. We evaluated the quality of these studies and used a weighted mean difference random affects model for the meta-analysis. We have collected 30 studies from 650 publications identified through systematic review describing the effects of 5 different type of stem cells on 12 different neurobehavioral scales with 1101 rodents or monkeys. Although there is lack of uniformity of the evaluation methods, these researches showed consistent improvements both in neurobehavioral function and structural outcomes. Besides, the quality of these studies needs to be raised. In conclusion, stem cells hold extensive potential in treating ICH, which should be further evaluated with more evidence-based, high-quality animal studies.

Stem cell therapy in intracerebral hemorrhage rat model

Intracerebral hemorrhage (ICH) is a very complex pathology, with many different not fully elucidated etiologies and prognostics. It is the most severe subtype of stroke, with high mortality and morbidity rates. Unfortunately, despite the numerous promising preclinical assays including neuroprotective, anti-hypertensive, and anti-inflammatory drugs, to this moment only symptomatic treatments are available, motivating the search for new alternatives. In this context, stem cell therapy emerged as a promising tool. However, more than a decade has passed, and there is still much to be learned not only about stem cells, but also about ICH itself, and how these two pieces come together. To date, rats have been the most widely used animal model in this research field, and there is much more to be learned from and about them. In this review, we first summarize ICH epidemiology, risk factors, and pathophysiology. We then present different methods utilized to induce ICH in rats, and examine how accurately they represent the human disease. Next, we discuss the different types of stem cells used in previous ICH studies, also taking into account the tested transplantation sites. Finally, we summarize what has been achieved in assays with stem cells in rat models of ICH, and point out some relevant issues where attention must be given in future efforts.

Intranasal delivery of hypoxia-preconditioned bone marrow-derived mesenchymal stem cells enhanced regenerative effects after intracerebral hemorrhagic stroke in mice

Intracerebral hemorrhagic stroke (ICH) causes high mortality and morbidity with very limited treatment options. Cell-based therapy has emerged as a novel approach to replace damaged brain tissues and promote regenerative processes. In this study we tested the hypothesis that intranasally delivered hypoxia-preconditioned BMSCs could reach the brain, promote tissue repair and improve functional recovery after ICH. Hemorrhagic stroke was induced in adult C57/B6 mice by injection of collagenase IV into the striatum. Animals were randomly divided into three groups: sham group, intranasal BMSC treatment group, and vehicle treatment group. BMSCs were pre-treated with hypoxic preconditioning (HP) and pre-labeled with Hoechst before transplantation. Behavior tests, including the mNSS score, rotarod test, adhesive removal test, and locomotor function evaluation were performed at varying days, up to 21days, after ICH to evaluate the therapeutic effects of BMSC transplantation. Western blots and immunohistochemistry were performed to analyze the neurotrophic effects. Intranasally delivered HP-BMSCs were identified in peri-injury regions. NeuN+/BrdU+ co-labeled cells were markedly increased around the hematoma region, and growth factors, including BDNF, GDNF, and VEGF were significantly upregulated in the ICH brain after BMSC treatment. The BMSC treatment group showed significant improvement in behavioral performance compared with the vehicle group. Our data also showed that intranasally delivered HP-BMSCs migrated to peri-injury regions and provided growth factors to increase neurogenesis after ICH. We conclude that intranasal administration of BMSC is an effective treatment for ICH, and that it enhanced neuroregenerative effects and promoted neurological functional recovery after ICH. Overall, the investigation supports the potential therapeutic strategy for BMSC transplantation therapy against hemorrhagic stroke.

Effects of infrasound on the growth of bone marrow mesenchymal stem cells: a pilot study

Poor viability of transplanted bone marrow mesenchymal stem cells (BMSCs) is well‑known, but developing methods for enhancing the viability of BMSCs requires further investigation. The aim of the present study was to elucidate the effects of infrasound on the proliferation and apoptosis of BMSCs, and to determine the association between survivin expression levels and infrasound on BMSCs. Primary BMSCs were derived from Sprague Dawley rats. The BMSCs, used at passage three, were divided into groups that received infrasound for 10, 30, 60, 90 or 120 min, and control groups, which were exposed to the air for the same durations. Infrasound was found to promote proliferation and inhibit apoptosis in BMSCs. The results indicated that 60 min was the most suitable duration for applied infrasound treatment to BMSCs. The protein and mRNA expression levels of survivin in BMSCs from the two treatment groups that received 60 min infrasound or air, were examined by immunofluorescence and quantitative polymerase chain reaction. Significant differences in survivin expression levels were identified between the two groups, as infrasound enhanced the expression levels of survivin. In conclusion, infrasound promoted proliferation and inhibited apoptosis in BMSCs, and one mechanisms responsible for the protective effects may be the increased expression levels of survivin.

Rapidly in situ forming platelet-rich plasma gel enhances angiogenic responses and augments early wound healing after open abdomen

Objective. The purposes of our present study were to evaluate the potential of platelet-rich plasma gel to enhance granulation tissue formation after open abdomen and to examine whether the effect was attributable to stimulating rapid neovascularization. Methods. Twenty-four rats underwent colon ascendens stent peritonitis surgery to induce sepsis, followed by intraperitoneal injection of nitrogen to create intra-abdominal hypertension. Four hours later, laparotomies were performed. The rats were randomized into three groups (n = 8 for each group): control, platelet-poor plasma (PPP), and platelet-rich plasma (PRP) groups. One week after the treatment, granulation tissue formation and angiogenesis were evaluated by histological and laser Doppler analysis. Results. The resultant platelet count in platelet-rich plasma was higher than that of PPP. The concentrations of platelet-derived growth factor BB, transforming growth factor β-1, and vascular endothelial growth factor in PRP were significantly higher when compared with that of PPP. Myofibroblast count, granulation tissue thickness, vessel numbers, and blood perfusion were increased in PRP group, followed by PPP group, with control being the least. Conclusion. Rapidly in situ forming platelet-rich plasma gel promoted remarkable neovascularization and early wound healing after open abdomen and may lead to novel and effective treatments for open abdominal wounds.

Antagonistic and synergistic effects of bone morphogenetic protein 2/7 and all-trans retinoic acid on the osteogenic differentiation of rat bone marrow stromal cells

The osteogenesis of bone marrow stromal cells (BMSCs) is of paramount importance for the repair of large-size bone defects, which may be compromised by the dietary-accumulated all-trans retinoic acid (ATRA). We have shown that heterodimeric bone morphogenetic protein 2/7 (BMP2/7) could induce bone regeneration in a significantly higher dose-efficiency in comparison with homodimeric BMPs. In this study, we evaluated the effects of ATRA and BMP2/7 on the proliferation, differentiation, mineralization and osteogenic genes. ATRA and BMP2/7 exhibited both antagonistic and synergistic effects on the osteogenesis of BMSCs. ATRA significantly inhibited proliferation and expression of osteocalcin but enhanced the activity of alkaline phosphatase of BMSCs. On day 21, 50 ng/mL BMP2/7 could antagonize the inhibitive effects of ATRA and significantly enhance osteogenesis of BMSCs. These findings suggested a promising application potential of heterodimeric BMP2/7 in clinic to promote bone regeneration for the cases with dietary accumulated ATRA.