Efficacy assessment of mesenchymal stem cell transplantation for burn wounds in animals: a systematic review

Comparison of the effects of epidermal growth factor mesenchymal stem cell and silver sulfadiazine on burn stasis zone

Objective

This study investigates the effects of adipose tissue-derived mesenchymal stem cell (MSC), human recombinant epidermal growth factor (EGF) and silver sulfadiazine (SSD) on wound healing in the burn stasis zone by applying the comb burn model in rats.

Material and Methods

A comb burn model was used for the burns and 32 Wistar albino female rats were randomly divided into four groups (control, SSD, SSD+MSC, SSD+EGF). On the 1st day and the 21st day, the total burn area on the 1st day and the healed, healing, and non-healing burn area on the 21st day were calculated with the Image-J program. At the end of the 21st day, the pathology samples taken after euthanasia were scored semiquantitatively in terms of epithelization, inflammatory cell density, fibroblast density, collagen amount, and angiogenesis after hematoxylin-eosin staining.

Results

Histopathological analysis demonstrated that epithelialization scores were highest in the MSC (3.88±0.35, p<0.001) and EGF (3.63±0.52) groups, while the control group had the lowest values (1.50±0.53). Inflammatory cell density was significantly lower in the MSC (1.50±0.53, p<0.001) and EGF (1.88±0.64) groups than in the control group (3.75±0.46). Similarly, fibroblast density was lowest in the MSC (1.38±0.52, p<0.001) and EGF (1.75±0.71) groups, while the control group had the highest values (3.63±0.52). Collagen fibril density was significantly increased in the MSC (3.88±0.35, p<0.001) and EGF (3.50±0.53) groups compared to the control (1.63±0.74). Angiogenesis was highest in the EGF group (3.75±0.46, p<0.001), followed by the MSC group (3.00±0.53), while the control group had the lowest values (1.25±0.46). These results suggest that MSC and EGF play a significant role in wound healing, with MSC demonstrating superior epithelialization and EGF exhibiting the greatest angiogenic effect. Photo-analytical measurements showed that on day 1, burn area sizes were similar among all groups (p>0.05). By day 21, the healing burn area was significantly smaller in the MSC (3.19±0.98 cm², p<0.001) and EGF (4.33±0.48 cm²) groups compared to the control (8.43±2.35 cm²). The non-healing area was smallest in the EGF group (0.67±0.49 cm²), followed by the MSC (1.06±0.49 cm², p<0.001) and SSD (1.91±0.75 cm²) groups, whereas the control group had the largest non-healing area (7.29±2.20 cm²). These findings suggest that MSC was the most effective treatment for promoting wound healing, followed by EGF and SSD.

Conclusion

We determined that both histologically and photo analytically, MSC and EGF provided faster wound healing in the burn stasis zone EGF gave better results than all groups in preventing necrosis.

Effect of adipose-derived stem cells exosomes cross-linked chitosan-αβ-glycerophosphate thermosensitive hydrogel on deep burn wounds

BACKGROUND

Burn wound management is challenging, and while mesenchymal stem cell-derived exosomes show therapeutic potential, optimal delivery methods are unclear.

AIM

To study chitosan (CS)-αβ-glycerophosphate (CS-αβ-GP) hydrogel crosslinked with adipose-derived stem cell exosomes (ASC-Exos) for healing deep burn injuries.

METHODS

Rats with deep burn injuries were divided into the CS + ASCs-Exos group, the ASCs-Exos group, the CS group, and the control group. The healing rates on days 4, 7, and 14 after treatment were analyzed using ImageJ software. On day 14, the tissues were stained with hematoxylin and eosin staining, Masson’s trichrome staining, and immunohistochemical analysis to evaluate tumor necrosis factor α, interleukin-6 (IL-6), IL-1α, IL-10, transforming growth factor β, and epidermal growth factor. The mRNA levels of IL-1α, CD86, C-C motif chemokine ligand 22, and CD163 were evaluated through quantitative polymerase chain reaction.

RESULTS

The CS + ASC-Exos group exhibited enhanced healing, reduced lymphocyte infiltration, blood vessels, and muscle fiber distribution. Increased IL-10, transforming growth factor β, and epidermal growth factor and decreased tumor necrosis factor α, IL-1α, and IL-6 expression were observed. Quantitative polymerase chain reaction revealed reduced IL-1α and CD86 and increased C-C motif chemokine ligand 22 and CD163 expression. Protein analysis showed downregulation of phosphorylated inhibitor of kappa Balpha and P65 in the nuclear factor κB (NF-κB) pathway. ASC-Exos crosslinked with CS-αβ-GP hydrogel demonstrates superior effects in anti-inflammation, wound healing promotion, and promotion of M1 macrophage transformation to M2 macrophage by blocking the NF-κB pathway compared to ASC-Exos alone.

CONCLUSION

Our research demonstrates that the ASC-Exos cross-linked CS-αβ-GP hydrogel represents an advanced therapeutic approach for treating deep burn wounds. It has anti-inflammatory effects, promotes wound healing, and facilitates the transition of M1 macrophages to M2 macrophages by blocking the NF-κB pathway.

Transient Fever: The Sole Treatment-Related Adverse Event Associated with Mesenchymal Stromal Cells and Solid Clues from the Real World

BACKGROUND

The number of trials investigating mesenchymal stromal cells (MSCs) soars within 3 years which urges a study analysing emerging MSC treatment-related adverse events.

AIM

To assess the safety of MSC therapy and provide solid evidence for clinical translation of MSC.

METHODS

A meta-analysis of randomized clinical trials (RCTs) published up to April 20th, 2023 was performed. Odds ratio (OR) and 95% confidential intervals (CIs) were used to display pooled results.

RESULTS

152 randomized clinical trials (RCTs) that incorporated 9228 individuals treated with MSCs from autologous or allogenic adipose tissue, bone marrow, Wharton's Jelly, and placenta tissue were included in the analysis. We discovered appropriate 21 MSC treatment-related adverse events (TRAEs), of which fever [OR, 1.61, 95% CI: 1.22-2.11, p<0.01] was the sole event that was closely associated with MSC therapy. MSCs also trended to lower the incidence rate of tachycardia [OR, 0.83, 95% CI: 0.64-1.09, p=0.14] and fatigue [OR, 0.18, 95% CI: 0.61-1.07, p=0.18]. A separate analysis of studies with long-term follow-up (more than 1 year) demonstrated the close relationship between MSCs and fever [OR, 1.75, 95% CI: 1.26-2.24, p<0.01]. The rest TRAEs did not associate themselves with MSC therapy. Dose-response was also conducted for fever, linearity was discovered between MSCs from allogeneic tissue and Wharton's Jelly and fever.

CONCLUSION

To date, our results suggest that fever is the only AE closely associated with MSCs.

Ameliorative potential of stem cells from human exfoliated deciduous teeth (SHED) in preclinical studies: A meta-analysis

The preclinical and clinical role of mesenchymal stem cells from various adult sources is extensively investigated and established in regenerative medicine. However, the comprehensive exploration of the therapeutic potential of Stem cells from human exfoliated deciduous teeth (SHED) is inadequate. Therefore, we performed a systematic meta-analysis of preclinical animal model studies in several diseases to provide insight into SHED's efficacy and therapeutic potential. Two blinded and independent investigators searched the available online databases and scrutinized the included studies. Meta-analysis was performed to evaluate the pooled effect estimate of intervention of SHED by Review Manager 5.4.1. To investigate the therapeutic efficacy of SHED intervention, we also analyzed the test of heterogeneity (I2), overall effect (Z), sensitivity, and publication bias. Among the 2156 scrutinized studies, 40 were included and evaluated as per inclusion and exclusion criteria. The intervention of SHED and its derivatives in several diseases depicted statistically significant therapeutic effects in periodontitis, pulpitis, spinal cord injury, parkinson's disease, alzheimer's disease, focal cerebral ischemia, peripheral nerve injury, and retinal pigmentosa. SHED also improved levels of alanine aminotransferase, aspartate aminotransferase, and bilirubin in liver fibrosis . In autoimmune diseases also, values were significant. SHED also showed a statistically significant reduction of wound healing area and new bone formation in bone defects. The pooled effect estimates of included preclinical studies demonstrated a statistically significant therapeutic effect of SHED in numerous diseases. Based on our data, it is suggested that the potential of SHED may be implemented in clinical trials after conducting a few more preclinical studies.

Burn wound conversion: clinical implications for the treatment of severe burns

The identification of novel treatments for severe burn wounds relies on accurate clinical assessments of the extent of injury. However, evaluation of burn wound depth can be challenging due to the tendency for burn wounds to progress over time in a little-understood process known as 'burn wound conversion'. Local factors affecting the burn wound, such as inflammation, oxidative stress-induced tissue damage, vasostasis and bacterial infections, lead to increased cell death by apoptosis or oncosis, while systemic events may promote burn wound conversion. Acute shock, metabolic derangements, age or immunomodulation can modify cytokine secretion, lower immune responses, decrease blood flow or cause bacterial infection at the burn wound site. Therefore, therapeutic approaches targeting specific mechanisms that reduce cell death, improve wound reperfusion and promote tissue regrowth should favourably enhance burn wound healing, and long-term functional and aesthetic outcomes. Our current understanding of these mechanisms mostly comes from animal studies, underscoring the need for extensive research in humans. A streamlined approach would be to investigate the parallels in other disease states that exhibit ischaemia and potential reperfusion, such as ischaemic stroke and myocardial infarction. Moreover, in view of the limited knowledge available on the subject, the need exists for further clinical research into burn wound conversion and novel target pathways to ameliorate its effects. This review describes events that affect the viability of cells at the burn wound site resulting in burn wound conversion, and identifies potential targets for clinical interventions that may diminish burn wound conversion.

Mesenchymal Stem Cells in Burn Wound Management

Mesenchymal stem cells have a known regenerative potential and are used in many indications. They secrete many growth factors, including for fibroblasts (FGF), endothelium (VEGF), as well as 14 anti-inflammatory cytokines, and they stimulate tissue regeneration, promoting the secretion of proteins and glycosaminoglycans of extracellular matrices, such as collagen I, II, III, and V, elastin, and also metalloproteinases. They secrete exosomes that contain proteins, nucleic acids, lipids, and enzymes. In addition, they show the activity of inactivating free radicals. The aim of this study was an attempt to collect the existing literature on the use of stem cells in the treatment of a burn wound. There were 81 studies included in the analysis. The studies differed in terms of the design, burn wound model, source of stem cells, and methods of cellular therapy application. No major side effects were reported, and cellular therapy reduced the healing time of the burn wound. Few case reports on human models did not report any serious adverse events. However, due to the heterogeneity of the evidence, cellular therapy in burn wound treatment remains an experimental method.

LPS-pretreatment adipose-derived mesenchymal stromal cells promote wound healing in diabetic rats by improving angiogenesis

Mesenchymal stem cells (MSCs) play a key role in wound healing, and the advantages of pretreated MSCs in wound healing have previously been reported. In the present study, we investigated the impact of LPS pretreated human adipose-derived MSCs on skin wound healing in diabetic rats. We found that some improvements occurred through improving angiogenesis. Then, we scrutinized the impact of lipopolysaccharide (LPS) treatment on human adipose-derived MSCs in a high-glucose (HG) medium, as an in vitro diabetic model. In vivo findings revealed significant improvements in epithelialization and angiogenesis of diabetic wounds which received LPS pre-MSCs. Particularly, LPS pre-MSCs-treated diabetic wounds reached considerably higher percentages of wound closure. Also, the granulation tissue of these wounds had higher pronounced epithelialization and more vascularization compared with PBS-treated and MSCs-treated diabetic ones by CD31, VEGF, CD90, collagen 1, and collagen 3 immunostaining. Western-blots analyses indicated that LPS pre-MSCs led to the upregulation of vascular endothelial growth factor (VEGF) and DNMT1. In addition, significantly higher cell viability (proliferation/colonie), and elevated VEGF and DNMT1 protein expression were observed when MSCs were treated with LPS (10 ng/ml, 6 h) in HG culture media. Based on these findings, it is suggested that LPS pre-MSCs could promote wound repair and skin regeneration, in some major processes, via the improvement of cellular behaviors of MSCs in the diabetic microenvironment. The beneficial advantages of LPS treated with mesenchymal stem cells on wound healing may lead to establishing a novel approach as an alternative therapeutic procedure to cure chronic wounds in diabetic conditions.

Cellular Therapeutics for Chronic Wound Healing: Future for Regenerative Medicine

Chronic wounds are associated with significant morbidity and mortality, which demand long-term effective treatment and represent a tremendous financial strain on the global healthcare systems. Regenerative medicines using stem cells have recently become apparent as a promising approach and are an active zone of investigation. They hold the potential to differentiate into specific types of cells and thus possess self-renewable, regenerative, and immune-modulatory effects. Furthermore, with the rise of technology, various cell therapies and cell types such as Bone Marrow and Adipose-derived Mesenchymal Cell (ADMSC), Endothelial Progenitor Cells (EPCs), Embryonic Stem Cells (ESCs), Mesenchymal Stem Cell (MSCs), and Pluripotent Stem Cells (PSCs) are studied for their therapeutic impact on reparative processes and tissue regeneration. Cell therapy has proven to have substantial control over enhancing the quality and rate of skin regeneration and wound restoration. The literature review brings to light the mechanics of wound healing, abnormalities resulting in chronic wounds, and the obstacles wound care researchers face, thus exploring the multitude of opportunities for potential improvement. Also, the review is focused on providing particulars on the possible cell-derived therapeutic choices and their associated challenges in healing, in the context of clinical trials, as solutions to these challenges will provide fresh and better future opportunities for improved study design and therefore yield a substantial amount of data for the development of more specialized treatments.

Mesenchymal stem cells against intestinal ischemia-reperfusion injury: a systematic review and meta-analysis of preclinical studies

Background

Intestinal ischemia–reperfusion injury (IRI) causes localized and distant tissue lesions. Multiple organ failure is a common complication of severe intestinal IRI, leading to its high rates of morbidity and mortality. Thus far, this is poorly treated, and there is an urgent need for new more efficacious treatments. This study evaluated the beneficial effects of mesenchymal stem cells (MSCs) therapy on intestinal IRI using many animal experiments.

Methods

We conducted a comprehensive literature search from 4 databases: Pubmed, Embase, Cochrane library, and Web of science. Primary outcomes included the survival rate, Chiu’s score, intestinal levels of IL-6, TNF-α and MDA, as well as serum levels of DAO, D-Lactate, and TNF-α. Statistical analysis was carried out using Review Manager 5.3.

Results

It included Eighteen eligible researches in the final analysis. We demonstrated that survival rates in animals following intestinal IRI were higher with MSCs treatment compared to vehicle treatment. Besides, MSCs treatment attenuated intestinal injury caused by IRI, characterized by lower Chiu’s score (− 1.96, 95% CI − 2.72 to − 1.19, P < 0.00001), less intestinal inflammation (IL-6 (− 2.73, 95% CI − 4.19 to − 1.27, P = 0.0002), TNF-α (− 3.00, 95% CI − 4.74 to − 1.26, P = 0.0007)) and oxidative stress (MDA (− 2.18, 95% CI − 3.17 to − 1.19, P < 0.0001)), and decreased serum levels of DAO (− 1.39, 95% CI − 2.07 to − 0.72, P < 0.0001), D-Lactate (− 1.54, 95% CI − 2.18 to − 0.90, P < 0.00001) and TNF-α (− 2.42, 95% CI − 3.45 to − 1.40, P < 0.00001). The possible mechanism for MSCs to treat intestinal IRI might be through reducing inflammation, alleviating oxidative stress, as well as inhibiting the apoptosis and pyroptosis of the intestinal epithelial cells.

Conclusions

Taken together, these studies revealed that MSCs as a promising new treatment for intestinal IRI, and the mechanism of which may be associated with inflammation, oxidative stress, apoptosis, and pyroptosis. However, further studies will be required to confirm these findings.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13287-022-02896-y.

Bone marrow mesenchymal stem cells enhance angiogenesis and promote fat retention in fat grafting via polarized macrophages

Background

Fat grafting is one of the most common soft tissue filling methods in plastic surgery. Bone marrow mesenchymal stem cell (BM-MSC) transplantation is an effective method for improving graft retention. However, the role of BM-MSCs in fat transplantation is not completely clear.

Methods

Human fat particles, together with BM-MSCs or PBS as a control, were subcutaneously transplanted into the backs of nude mice. Samples were taken on days 14, 30 and 90 post-grafting to calculate the fat graft retention rate, and tissue staining was evaluated. Furthermore, macrophages were treated with BM-MSC conditioned medium (BM-MSC-CM) to identify the beneficial component secreted by these stem cells.

Results

In this study, we found that BM-MSCs improved retention by enhancing angiogenesis in fat grafting. Further analysis revealed that BM-MSCs could significantly inhibit the expression of the proinflammatory M1 macrophage markers interleukin (IL)-1β, tumor necrosis factor-α (TNF-α) and IL-6 in the early stages of fat grafting and promote the expression of the anti-inflammatory M2 macrophage markers Arg1, IL-10 and VEGF. Furthermore, our results showed that IL-10 secreted by BM-MSCs induced M2 macrophage polarization in vitro.

Conclusions

BM-MSC transplantation can improve the fat retention rate and promote angiogenesis, which may be related to M2 macrophages. These results help elucidate the role of BM-MSCs in fat grafting.

Preclinical and Clinical Amelioration of Bone Fractures with Mesenchymal Stromal Cells: a Systematic Review and Meta-Analysis

Even though reunion of bone fracture confronts clinicians, mesenchymal stromal cells (MSCs) are investigated to be curative in bone fracture. This study aimed to explore the application potential of MSCs for healing bone fractures. By inputting search terms and retrieving studies published up to March 2021, multiple databases, including PubMed, EMBASE, Web of Science, and Cochrane Library, were searched to identify eligible studies. The mean difference (MD) and 95% confidence interval (95% CI) were calculated to analyze the main results in the meta-analysis. Data analysis was performed using Engauge Digitizer 10.8 and R Software. Of the 31 articles, 26 were preclinical studies (n = 913), and 5 were clinical trials (n = 335). Preclinically, MSCs therapy significantly augmented the progress of bone regeneration [(bone volume over tissue volume (MD7.35, p < 0.01)], despite some non-significant effects (on the callus index, bone strength, work to failure, and stiffness). Clinically, the MSC group had a significantly reduced incidence of poor recovery (odds ratio (OR) 0.30, p < 0.01); however, a significant decrease in healing time was not observed in the MSC group (MD 2.47, p = 0.26). In summary, our data suggest that patients with bone fractures benefited from MSC administration and that MSCs are a potentially useful agent for bone regeneration. Despite these satisfactory outcomes, larger randomised clinical trials (RCTs) are necessary to confirm these findings.