Allogeneic Mesenchymal Stem Cells Research Articles

Bioengineered MSCCxcr2 transdifferentiated keratinocyte-like cell-derived organoid potentiates skin regeneration through ERK1/2 and STAT3 signaling in diabetic wound

Skin regeneration is severely compromised in diabetic foot ulcers. Allogeneic mesenchymal stem cell (MSC) transplantation is limited due to the poor engraftment, mitogenic, and differentiation potential in the harsh wound microenvironment. Thus, to improve the efficacy of cell therapy, the chemokine receptor Cxcr2 was overexpressed in MSCs (MSCCxcr2). CXCL2/CXCR2 axis induction led to the enhanced proliferation of MSCs through the activation of STAT3 and ERK1/2 signaling. Transcriptional upregulation of FGFR2IIIb (KGF Receptor) promoter by the activated STAT3 and ERK1/2 suggested trans-differentiation of MSCs into keratinocytes. These stable MSCCxcr2 in 2D and 3D (spheroid) cell cultures efficiently transdifferentiated into keratinocyte-like cells (KLCs). An in vivo therapeutic potential of MSCCxcr2 transplantation and its keratinocyte-specific cell fate was observed by accelerated skin tissue regeneration in an excisional splinting wound healing murine model of streptozotocin-induced type 1 diabetes. Finally, 3D skin organoids generated using MSCCxcr2-derived KLCs upon grafting in a relatively avascular and non-healing wounds of type 2 diabetic db/db transgenic old mice resulted in a significant enhancement in the rate of wound closure by increased epithelialization (epidermal layer) and endothelialization (dermal layer). Our findings emphasize the therapeutic role of the CXCL2/CXCR2 axis in inducing trans-differentiation of the MSCs toward KLCs through the activation of ERK1/2 and STAT3 signaling and enhanced skin regeneration potential of 3D organoids grafting in chronic diabetic wounds.

Genetic reprogramming with stem cells regenerates glomerular epithelial podocytes in Alport syndrome.

Glomerular filtration relies on the type IV collagen (ColIV) network of the glomerular basement membrane, namely, in the triple helical molecules containing the α3, α4, and α5 chains of ColIV. Loss of function mutations in the genes encoding these chains (Col4a3, Col4a4, and Col4a5) is associated with the loss of renal function observed in Alport syndrome (AS). Precise understanding of the cellular basis for the patho-mechanism remains unknown and a specific therapy for this disease does not currently exist. Here, we generated a novel allele for the conditional deletion of Col4a3 in different glomerular cell types in mice. We found that podocytes specifically generate α3 chains in the developing glomerular basement membrane, and that its absence is sufficient to impair glomerular filtration as seen in AS. Next, we show that horizontal gene transfer, enhanced by TGFβ1 and using allogenic bone marrow-derived mesenchymal stem cells and induced pluripotent stem cells, rescues Col4a3 expression and revive kidney function in Col4a3-deficient AS mice. Our proof-of-concept study supports that horizontal gene transfer such as cell fusion enables cell-based therapy in Alport syndrome.

Comparison of the therapeutic effects of mesenchymal stem cells derived from human dental pulp (DP), adipose tissue (AD), placental amniotic membrane (PM), and umbilical cord (UC) on postmenopausal osteoporosis.

Background: Osteoporosis is a systemic bone disease characterized by bone loss and microstructural degeneration. Recent preclinical and clinical trials have further demonstrated that the transplantation of mesenchymal stem cells (MSCs) derived from human adipose tissue (AD), dental pulp (DP), placental amniotic membrane (AM), and umbilical cord (UC) tissues can serve as an effective form of cell therapy for osteoporosis. However, MSC-mediated osteoimmunology and the ability of these cells to regulate osteoclast-osteoblast differentiation varies markedly among different types of MSCs. Methods: In this study, we investigated whether transplanted allogeneic MSCs derived from AD, DP, AM, and UC tissues were able to prevent osteoporosis in an ovariectomy (OVX)-induced mouse model of osteoporosis. The homing and immunomodulatory ability of these cells as well as their effects on osteoblastogenesis and the maintenance of bone formation were compared for four types of MSCs to determine the ideal source of MSCs for the cell therapy-based treatment of OVX-induced osteoporosis. The bone formation and bone resorption ability of these four types of MSCs were analyzed using micro-computed tomography analyses and histological staining. In addition, cytokine array-based analyses of serological markers and bioluminescence imaging assays were employed to evaluate cell survival and homing efficiency. Immune regulation was determined by flow cytometer assay to reflect the mechanisms of osteoporosis treatment. Conclusion: These analyses demonstrated that MSCs isolated from different tissues have the capacity to treat osteoporosis when transplanted in vivo. Importantly, DP-MSCs infusion was able to maintain trabecular bone mass more efficiently with corresponding improvements in trabecular bone volume, mineral density, number, and separation. Among the tested MSC types, DP-MSCs were also found to exhibit greater immunoregulatory capabilities, regulating the Th17/Treg and M1/M2 ratios. These data thus suggest that DP-MSCs may represent an effective tool for the treatment of osteoporosis.

Bone Marrow-derived Mesenchymal Stem Cell Therapy in Retinitis Pigmentosa.

To determine the effectiveness of bone marrow-derived mesenchymal stem cell therapy on visual acuity and visual field in patients with retinitis pigmentosa. Stem cell treatment in retinitis pigmentosa provides improvement in visual acuity and visual field. Forty-seven eyes of 27 patients diagnosed with retinitis pigmentosa were included in our study. Allogeneic bone marrow-derived mesenchymal stem cells were administered by deep subtenon injection. Complete routine ophthalmological examinations, optical coherence tomography (Zeiss, Cirrus HD-OCT) measurements, and visual field (Humphrey perimetry, 30-2) tests were performed on all patients before the treatment and on the 1st, 3rd, and 6th month after treatment. The best corrected visual acuities of the patients were determined by the Snellen chart and converted to logMAR. Visual evoked potential (VEP) and electroretinogram (ERG) examinations of the patients before the treatment and on the 6th month after the treatment were performed (Metrovision) data were compared. Visual acuities were 0.74 ± 0.49 logMAR before treatment and 0.61 ± 0.46 logMAR after treatment. Visual acuity had a statistically significant increase (p < 0.001). The visual field deviation was found to be -27.16 ± 5.77 dB before treatment and -26.59 ± 5.96 dB after treatment (p = 0.005). The ganglion cell layer was 46.26 ± 12.87 μm before treatment and 52.47 ± 12.26 μm after treatment (p = 0.003). There was a significant improvement in Pattern VEP 120º P100 amplitude compared to that before the treatment (4.43 ± 2.42 μV) and that after the treatment (5.09 ± 2.86 μV) (p = 0.013). ERG latency measurements were 18.33 ± 15.39 μV before treatment and 20.87 ± 18.64 μV after treatment for scotopic 0.01 (p = 0.02). ERG latency measurements for scotopic 3.0 were 20.75 ± 26.31 μV before treatment and 23.10 ± 28.60 μV after treatment (p = 0.014). Retinitis pigmentosa is a progressive, inherited disease that can result in severe vision loss. In retinitis pigmentosa, the application of bone marrow-derived mesenchymal stem cells by deep subtenon injection has positive effects on visual function. No systemic or ophthalmic side effects were detected in the patients during the 6-month follow-up period.

Therapeutic Effects of IL-1RA, M2 Cells, and their Synergistic Impact on a Mouse Model of Rheumatoid Arthritis

Purpose: Rheumatoid arthritis (RA) is a type of autoimmune disease that results in chronic inflammation of the joint synovial tissue, leading to joint damage and significant disability. Despite ongoing research, the exact cause of RA remains unclear, and current treatments have limitations. This study explores the potential of utilizing interleukin-1 receptor antagonist (IL-1RA) and anti-inflammatory macrophages polarized in the vicinity of the supernatant from allogeneic mesenchymal stem cells (MSCs) as a novel therapeutic approach for RA. Methods: An expression cassette containing the IL-1RA gene was constructed and expressed in E. coli BL21. The resulting protein was purified and stabilized for use in in vivo experiments. Bone marrow MSCs were isolated and used to produce anti-inflammatory M2 macrophages from the isolated peripheral blood monocytes. The macrophages were then used to treat mice with RA induced by collagen type II. Results: The combination of IL-1RA and M2 macrophages improved clinical and histopathological symptoms of the disease, reduced levels of inflammatory factors, and modulated the immune system in the treated mouse groups. The results showed that this combinatory therapy had a synergistic effect for RA treatment. Conclusion: The simultaneous use of IL-1RA and M2 cells could be a promising approach for the treatment of RA. This combinatory therapy has the potential to improve the disease and decrease the severity of inflammation in patients with RA. Keywords: Rheumatoid arthritis, IL-1RA, Anti-inflammatory macrophages, Synergistic effect, Novel therapeutic approach and Combinatory therapy

Implantation of hUCB-MSCs generates greater hyaline-type cartilage than microdrilling combined with high tibial osteotomy.

To compare the outcomes of treating large cartilage defects in knee osteoarthritis using human allogeneic umbilical cord blood-derived mesenchymal stem cell (hUCB-MSC) implantation or arthroscopic microdrilling as a supplementary cartilage regenerative procedure combined with high tibial osteotomy (HTO). This 1-year prospective comparative study included 25 patients with large, near full-thickness cartilage defects (International Cartilage Repair Society grade ≥ IIIB) in the medial femoral condyles and varus malalignment. Defects were treated with hUCB-MSC implantation or arthroscopic microdrilling combined with HTO. The primary outcomes were pain visual analogue scale and International Knee Documentation Committee subjective scores at 12, 24and 48 weeks. Secondary outcomes included arthroscopic, histologicaland magnetic resonance imaging assessments at 1 year. Fifteen and 10 patients were treated via hUCB-MSC implantation and microdrilling, respectively. Baseline demographics, limb alignmentand clinical outcomes did not significantly differ between the groups. Cartilage defects and total restored areas were significantly larger in the hUCB-MSC group (7.2 ± 1.9 vs. 5.2 ± 2.1 cm2, p = 0.023; 4.5 ± 1.4 vs. 3.0 ± 1.6 cm2, p = 0.035). The proportion of moderate-to-strong positive type II collagen staining was significantly higher in the hUCB-MSC group compared to that in the microdrilled group (93.3% vs. 60%, respectively). Rigidity upon probing resembled that of normal cartilage tissue more in the hUCB-MSC group (86.7% vs. 50.0%, p = 0.075). Histological findings revealed a higher proportion of hyaline cartilage in the group with implanted hUCB-MSC (p = 0.041). hUCB-MSC implantation showed comparable clinical outcomes to those of microdrilling as supplementary cartilage procedures combined with HTO in the short term, despite the significantly larger cartilage defect in the hUCB-MSC group. The repaired cartilage after hUCB-MSC implantation showed greater hyaline-type cartilage with rigidity than that after microdrilling. Level II, Prospective Comparative Cohort Study.

Preclinical assessments of safety and tumorigenicity of very high doses of allogeneic human umbilical cord mesenchymal stem cells

Human umbilical cord-mesenchymal stem cells (hUC-MSCs) have been widely investigated as a new therapeutic agent to treat injuries and inflammatory-mediated and autoimmune diseases. Previous studies have reported on the safety of low-dose infusion of hUC-MSCs, but information on the cell behaviour at higher doses and frequency of injection of the cells remains uncertain. The aim of the present study was to demonstrate the safety and efficacy of hUC-MSCs by Cytopeutics® (Selangor, Malaysia) from low to an extremely high dose in different monitoring periods in healthy BALB/c mice as well as assessing the tumorigenicity of the cells in B-NDG SCID immunocompromised mice. Umbilical cord from two healthy human newborns was obtained and the isolation of the hUC-MSCs was performed based on previous established method. Assessment of the cells at different doses of single or multiple administrations was performed on healthy BALB/c mice in dose range finding, sub-acute (7 d and 28 d) and sub-chronic periods (90 d). Tumorigenicity potential of Cytopeutics® hUC-MSCs was also evaluated on B-NDG immunocompromised mice for 26 wk. Single or multiple administrations of Cytopeutics® hUC-MSCs up to 40 × 106 cells per kilogramme of body weight (kg BW) were found to have no adverse effect in terms of clinical symptoms, haematology and other laboratory parameters, and histology examination in healthy BALB/c mice. hUC-MSCs were also found to reduce pro-inflammatory cytokines (IL-6 and TNF-α) in a dose-dependent manner. No sign of tumor formation was observed in B-NDG mice in the 26-wk tumorigenicity assessment. Single or multiple administration of allogenic Cytopeutics® hUC-MSCs was safe even at very high doses, is non-tumorigenic and did not cause adverse effects in mice throughout the evaluation periods. In addition, Cytopeutics® hUC-MSCs exhibited immunomodulatory effect in a dose-dependent manner.

Safety assessment of equine allogeneic tenogenic primed mesenchymal stem cells in horses with naturally occurring tendon and ligament injuries.

Mesenchymal stem cells provide a valuable treatment option in orthopedic injuries in horses. The aim of this study was to evaluate the hematological, biochemical, immunological and immunomodulatory parameters following intralesional treatment with tenogenic primed equine allogeneic peripheral blood-derived mesenchymal stem cells (tpMSCs) in client-owned horses with naturally occurring superficial digital flexor tendon (SDFT) and suspensory ligament (SL) injuries. The immunogenicity and immunomodulatory capacities of tpMSCs were assessed in a modified mixed lymphocyte reaction, including peripheral blood mononuclear cells (PBMCs) of 14 horses with SDFT and SL injuries after treatment with tpMSCs. In a second study, 18 horses with SDFT and SL injuries received either an intralesional injection with tpMSCs (n = 9) or no treatment (n = 9). The tpMSCs did not provoke a cellular immune response (p < 0.001) and were able to immunomodulate stimulated T lymphocytes (p < 0.001) in vitro. Therapeutic use of tpMSCs did not result in relevant hematologic or biochemical abnormalities. Both studies had a small sample size. No statistical analyses were performed in the second study. Fibrinogen was only analyzed in a single horse prior to treatment. Co-incubation of tpMSCs and PBMCs of horses that have been previously exposed to tpMSCs did not elicit a cellular immune response and tpMSCs were able to immunomodulate stimulated T lymphocytes. Intralesional treatment with tpMSCs did not provoke abnormal changes in hematological and biochemical parameters.

Bioengineered MSCGFPCxcr2-Mmp13 Transplantation Alleviates Hepatic Fibrosis by Regulating Mammalian Target of Rapamycin Signaling.

Aims: Hepatic fibrosis is the pathological change during chronic liver diseases (CLD) that turns into cirrhosis if not reversed timely. Allogenic mesenchymal stem cell (MSC) therapy is an alternative to liver transplantation for CLD. However, poor engraftment of the transplanted MSCs limits their therapeutic efficacy. MSCs express chemokine receptors that regulate their physiology. We observed several-fold increased expressions of Cxcl3 and decreased expression of Mmp13 in the fibrotic liver. Therefore, we bioengineered MSCs with stable overexpression of Cxcr2 (CXCL3-cognate receptor) and Mmp13, collagenase (MSCGFPCxcr2-Mmp13). Results: The CXCL3/CXCR2 axis significantly increased migration through the activation of AKT/ERK/mTOR signaling. These bioengineered MSCs transdifferentiated into hepatocyte-like cells (MSCGFPCxcr2-Mmp13-HLCs) that endured the drug-/hepatotoxicant-induced toxicity by significantly increasing the antioxidants-Nrf2 and Sod2, while decreasing the apoptosis-Cyt C, Casp3, Casp9, and drug-metabolizing enzyme-Cyp1A1, Cyp1A2, Cyp2E1 markers. Therapeutic transplantation of MSCGFPCxcr2-Mmp13 abrogated AAP-/CCl4-induced hepatic fibrosis in mice by CXCR2-mediated targeted engraftment and MMP-13-mediated reduction in collagen. Mechanistically, induction of CXCL3/CXCR2 axis-activated mTOR-p70S6K signaling led to increased targeted engraftment and modulation of the oxidative stress by increasing the expression and activity of nuclear Nrf2 and SOD2 expression in the regenerated hepatic tissues. A marked change in the fate of transplanted MSCGFPCxcr2-Mmp13 toward hepatocyte lineage demonstrated by co-immunostaining of GFP/HNF4α along with reduced COL1α1 facilitated the regeneration of the fibrotic liver. Innovation and Conclusions: Our study suggests the therapeutic role of allogenic Cxcr2/Mmp13-bioengineered MSC transplantation decreases the hepatic oxidative stress as an effective translational therapy for hepatic fibrosis mitigation-mediated liver regeneration.

Prognostic Factors for Clinical Outcome and Cartilage Regeneration after Implantation of Allogeneic Human Umbilical Cord Blood-Derived Mesenchymal Stem Cells in Large-Sized Cartilage Defects with Osteoarthritis.

To analyze the prognostic factors for clinical outcomes and cartilage regeneration after the implantation of allogeneic human umbilical cord blood mesenchymal stem cell (hUCB-MSC) for treating large-sized cartilage defects with osteoarthritis. This study is a case-series with multiple subgroup analyses that divides the included patients into multiple subgroups based on various factors. Overall, 47 patients who underwent hUCB-MSC implantation were included. The patient-reported outcomes, magnetic resonance imaging (MRI), and second-look arthroscopy were used to assess the outcomes. Combined realignment surgery significantly correlated with clinical outcomes, particularly pain. No other factors significantly influenced the clinical outcomes in short-term period. Subgroups with large defect sizes or meniscal insufficiency showed significantly poor MRI and arthroscopy outcomes (MRI, P = 0.001, P = 0.001; arthroscopy, P = 0.032, P = 0.042). The logistic regression showed that patients with a 1 cm2 larger defect size were 1.91 times less likely to achieve favorable MRI outcomes (P = 0.017; odds ratio [OR], 1.91). Cut-off value to predict the poor outcome was >5.7 cm2 (area under the curve, 0.756). A cartilage defect size >5.7 cm2 was the major poor prognostic factor for cartilage regeneration on MRI (P = 0.010; OR, 17.46). If the postoperative alignment shifted by 1° opposite to the cartilage defect, it was 1.4 times more likely to achieve favorable MRI outcomes (P = 0.028; OR, 1.4). Combining realignment surgery showed a better prognosis for pain improvement. Cartilage defect size, meniscal function, and postoperative alignment are significant prognostic factors for cartilage regeneration. A cartilage defect size >5.7 cm2 was significantly related to poor cartilage regeneration.

Allogeneic umbilical cord blood-derived mesenchymal stem cell implantation versus microdrilling combined with high tibial osteotomy for cartilage regeneration

This study compared cartilage regeneration outcomes in knee osteoarthritis (OA) using allogeneic human umbilical cord blood-derived mesenchymal stem cell (hUCB-MSC) implantation and microdrilling with high tibial osteotomy (HTO). Fifty-four patients (60 knees) were included: 24 (27 knees) in the hUCB-MSC group and 30 (33 knees) in the microdrilling group. Both groups showed significant improvements in pain and functional scores at 6, 12, and 24 months compared to baseline. At 24 months, the hUCB-MSC group had significantly improved scores. Arthroscopic assessment at 12 months revealed better cartilage healing in the hUCB-MSC group. In subgroup analysis according to the defect site, hUCB-MSC implantation showed superior cartilage healing for anterior lesions. In conclusion, both treatments demonstrated effectiveness for medial OA. However, hUCB-MSC implantation had better patient-reported outcomes and cartilage regeneration than microdrilling. The study suggests promising approaches for cartilage restoration in large knee defects due to OA.

Revolutionizing Endodontics: Innovative Approaches for Treating Mature Teeth With Closed Apices and Apical Lesions: A Report of Two Cases

Modern tissue engineering strategies have elucidated the potential of regenerative endodontic treatment (RET) as an alternative for treating mature teeth. Here, we report 2 cases in which cell-based RET (CB-RET) using encapsulated allogeneic umbilical cord mesenchymal stem cells (UC-MSCs) in a platelet-poor plasma (PPP)-based scaffold was used in 2 mature teeth with pulp necrosis and apical periodontitis. After 5 years of follow-up, the healing response was satisfactory in both cases, with evidence of pulp revitalization. This is the first study to report the success of an extended, 5-year follow-up for allogeneic CB-RET. This report presents an innovative and sustainable solution to challenging endodontic scenarios.

(228) Cell-Based Therapy Can Restore Erectile Function in Men with Type 2 Diabetes and Metabolic Syndrome by Promoting Angiogenesis and Endothelial Repair

Abstract Introduction Although there has been a growing interest in restorative therapies for erectile dysfunction (ED) in recent years, there is still limited mechanistic evidence to support their effectiveness in the clinical setting. Objective The goal of this research was to investigate the mechanistic impact of cell-based therapy in men with ED secondary to Type 2 Diabetes Mellitus (DM2) and Metabolic Syndrome (MetS) through analysis of plasma biomarkers. Methods International Index of Erectile Function (IIEF) was completed by all men in the ACESO (NCT02886884) and CERES (NCT03059355) clinical trials. ACESO and CERES were both randomized, blinded, pilot phase clinical trials in which all participants received cellular therapy at varying doses and sources to treat endothelial dysfunction secondary to either DM2 or MetS, respectively. The intervention in both trials was peripheral intravenous infusion of allogeneic Mesenchymal Stem Cells (MSCs) of either 20 or 100 million cells derived from either bone marrow (BM) or umbilical cord tissue (UC). Follow-up was for 1 year. Endothelial function was measured via Brachial Artery Flow Mediated Vasodilation (FMD) and Endothelial Progenitor Cell-Colony Forming Units (EPC-CFU) assay. Plasma aliquots were isolated from blood samples and subjected to multiplex ELISA assay for analysis of angiogenic biomarkers. Results Data was pooled from all 20 men in the ACESO and CERES clinical trials. Overall, 7 received 20 million BM-MSCs, 9 received 100 million BM-MSCs, 2 received 20 million UC-MSCs, and 2 received 100 million UC-MSCs. There were no treatment emergent serious adverse effects (TE-SAEs) within 30 days following infusion in any of the participants. Among men with ED (IIEF-EF&amp;lt;25), 31.25% achieved MCID in erectile function. Participants with mild or moderate ED at baseline showed greater improvements in erectile function and endothelial function compared to those with severe ED. Participants who achieved MCID following cell therapy also experienced statistically significant improvements in FMD (P=0.05), whereas those who did not achieve MCID or had normal erectile function at baseline did not experience an improvement in FMD. Furthermore, men with Metabolic Syndrome who met MCID criteria were found to have increased Angiopoietin 1 and decreased Angiopoietin 2 following cell therapy. Conclusions The findings of this study demonstrate the potential of cell-based therapies in improving erectile function, angiogenic, and endothelial function. Future studies should aim to identify the causative mechanisms underlying these restorative effects in humans, paving the way for enhanced understanding and optimization of such therapies. Disclosure Any of the authors act as a consultant, employee or shareholder of an industry for: Longeveron LLC.

OP18 Efficacy and safety of darvadstrocel treatment in patients with complex perianal fistulas and Crohn’s Disease: results from the global ADMIRE-CD II phase 3 study

Abstract Background Complex perianal fistulas are a serious complication in patients with Crohn’s disease (CD). Darvadstrocel (DVS), a suspension of expanded adult allogeneic adipose-derived mesenchymal stem cells, is approved in Europe and Japan for treatment of complex Crohn’s perianal fistulas (CPF). The global ADMIRE-CD II phase 3 randomized double-blind placebo-controlled study evaluated the efficacy and safety of DVS for treatment of complex CPF. Methods Patients aged 18–75 years with clinically controlled, inactive or mildly active CD and complex CPF (≤2 internal openings [IO] and ≤3 external openings [EOs]) who had an inadequate, or a loss of response to immunosuppressive agents or biologics were included. Patients were randomized 1:1 to receive a local injection of DVS as a single dose (120 x 106 cells/24 mL) or placebo. In all patients, fistula preconditioning included vigorous curettage and seton placement 2–3 weeks before treatment, and seton removal, a further curettage and closure of IOs immediately before treatment. The primary endpoint was combined remission (closure of all treated EOs that were draining at baseline, despite gentle finger compression, and absence of collections &amp;gt;2 cm confirmed by MRI) at 24 weeks. Secondary endpoints included combined remission at 52 weeks, clinical remission (closure of all treated EOs without MRI confirmation) at 24 and 52 weeks, and time to clinical remission at 24 weeks. Safety was monitored up to 52 weeks. Results From 19 Oct 2017 to 26 Jul 2023, 568 patients received DVS (n = 283) or placebo (n = 285) with fistula preconditioning; 56.3% of patients enrolled in Europe and Israel, and 43.7% in North America. Mean (SD) age, sex and race were similar in the DVS and placebo arms (38.4 [11.9] vs 37.7 [10.8] years; 42.8% vs 45.6% female; 85.9% vs 89.1% White). Combined remission rates at 24 weeks did not statistically differ between treatments (48.8% DVS vs 46.3% placebo) and there were no differences in secondary endpoints (Table 1; Figure 1). Based on health authority guidelines, post hoc analyses of patients randomized before COVID-19 (11 March 2020; n = 141 DVS, n = 143 placebo) were performed: combined remission rates at 24 weeks were 46.8% (DVS) and 38.5% (placebo). The safety profile for DVS was consistent with prior studies with no new safety signals (Table 1). Conclusion The efficacy outcomes assessed did not statistically differ between DVS and placebo, and the placebo response rate (with fistula preconditioning) was higher than expected. Post hoc analyses revealed lower placebo response rates in patients randomized before COVID-19 (similar to the pivotal ADMIRE CD I study) than the overall placebo arm. DVS was well tolerated.

DOP66 INSPIRE: Preliminary data from an observational post-marketing registry on the effectiveness and safety of darvadstrocel in patients with Crohn’s Disease and complex perianal fistulas

Abstract Background Darvadstrocel (DVS), a suspension of expanded allogeneic adipose-derived mesenchymal stem cells, is approved for the treatment of complex Crohn’s perianal fistulas (CPF). INSPIRE (EUPAS24267) is a European observational post-approval study evaluating real-world effectiveness and safety of DVS in patients with complex CPF for up to 36 months. Here we report preliminary clinical and safety outcomes from INSPIRE. Methods Patients with complex CPF who had received DVS according to local standard practice were eligible to enrol. Clinical response (closure of ≥50% of external openings [EOs]) and clinical remission (closure of all EOs) of DVS-treated fistulas that were draining at baseline, were evaluated in the all-treated (AT; received ≥1 dose of DVS with an evaluation for fistula response after 6 months) and per-protocol (PP; received DVS as per label-approved guidelines) cohorts. Treatment-emergent adverse events (TEAEs), serious TEAEs and AEs of special interest were reported for the safety cohort (all patients treated with DVS). Results As of April 2023, 652 patients had enrolled (Table 1). Complete data to evaluate 12-month clinical response and remission were available for 134 (AT cohort) and 124 (PP cohort) patients, of whom 79.9% (AT, n = 107) and 79.8% (PP, n = 99) had a clinical response and 76.1% (AT, n = 102) and 76.6% (PP, n = 95) had clinical remission (Figure 1). From baseline to Month 12, there was a decrease in the mean (standard deviation [SD]) Perianal Disease Activity Index score (–3.5 [3.3]; n/N = 96/302 and –3.7 [3.2]; n/N = 89/249) and a decrease in the mean (SD) Harvey–Bradshaw Index for Crohn’s disease activity (-0.3 [2.8]; n/N = 102/302 and -0.4 [2.9]; n/N = 95/249) in the AT and PP cohorts, respectively. Complete safety data were available for 619 patients (median [min–max] follow-up 480 [6–1595]) days. Overall, 26% (n = 162) had ≥1 TEAE and 10% (n = 63) ≥1 serious TEAE. The most frequent TEAEs were anal abscess (6.9%), COVID-19 (1.9%) and proctalgia (1.1%). No deaths were reported. One breast cancer lymph node metastasis and one ovarian epithelial cancer were reported; both events were confounded by immunosuppressant treatment and were not considered related to DVS treatment. Conclusion These preliminary data are consistent with the pivotal ADMIRE-CD study and demonstrate a single dose of DVS in patients with complex CPF is associated with positive clinical outcomes in up to 80% of patients, and a favourable safety profile, both of which are maintained after 12 months. The inherent limitations of registry-based studies mean these data should be interpreted with caution. However, the ongoing INSPIRE study will provide longer follow-up data to confirm these observations with respect to any study limitations.

P541 Long-term follow-up results of darvadstrocel for complex perianal fistulas in patients with Crohn's disease: 3-year outcomes from a Japanese phase 3 study

Abstract Background Darvadstrocel (DVS), a suspension of expanded human allogeneic mesenchymal stem cells extracted from adipose tissue, is for the treatment of complex perianal fistulas in patients with Crohn's disease (CD). In Japan, DVS was approved in 2021 based on the Japanese phase 3 study Week 52 data combined with the pivotal study ADMIRE-CD data. Patients who participated in the Japanese study were monitored for 3 years, and we report the results at Week (W) 156. Methods This was an open-label, uncontrolled, phase 3 study (converted to a post-marketing clinical study after approval) conducted from March 2019 to February 2023 in Japan. Subjects had complex Crohn’s perianal fistulas (CPF) refractory to conventional treatments with a maximum of 2 internal openings (IO) and 3 external openings (EO). The fistula tract was curetted approximately 2-3 weeks before DVS administration, and a drainage seton was placed. On the day of administration, seton was removed, fistula tracts were curetted again, and IO was sutured. A total of 24 mL of DVS (including 120x106 cells) was administered around the IO and into the wall of fistula tracts. During the 2-year follow-up period after W52, medical and surgical treatment for CD and CPF was given as needed, and subjects were assessed every 6 months. Results 22 Japanese patients were enrolled from 9 sites. The mean (SD) age was 36.4 (10.4) years, 63.6% were male, and the mean (SD) duration of CD was 11.3 (6.6) years. By W156, most frequently reported adverse events (AE) were anal fistula (7/22), proctalgia (7/22), and nasopharyngitis (6/22). New serious AE occurred after W52 were found in 9 subjects: COVID-19 (4), CD (2), perianal fistula, small bowel obstruction, premature labour (1 each). None of these were considered DVS-related. At W156, the combined remission rate (clinical and MRI assessment) was 15/22 (68.2%, 95% CI [48.7%, 87.6%]), clinical remission rate (clinical assessment) was 15/22 (68.2%, 95% CI [48.7%, 87.6%]), response rate (no drainage from ≥50% of treated EOs) was 20/22 (90.9%, 95% CI [78.9%, 100.0%]), and relapse rate (at least 1 relapse by W156 after achieving remission at W52) was 3/15 (20.0%, 95% CI [0.0%, 40.2%]). Mean Perianal Disease Activity Index (PDAI) total score (SD) was 4.8 (2.2) at baseline, which was decreased to 2.1 (2.1) at W52, and 1.7 (2.0) at W156. Mean Crohn's Disease Activity Index (CDAI) total score (SD) was 94.3 (60.1) on the day of administration, which was decreased to 73.7 (73.6) at W52, and 71.4 (51.2) at W156. Conclusion This is the first prospectively observed clinical outcomes in CPF for 3 years after DVS administration. There were no new safety findings, and fistula remission observed at W52 was maintained until W156.

Medical Consequences and Treatment of Injuries Caused by White Phosphorus Munitions

White phosphorus (WP) has been used in hand grenades, mortar and artillery shells, and aerial bombs since World War I. Recently it has been used in combat operations in Iraq, Syria, Afghanistan, Yemen, Nagorno-Karabakh and is used during the Palestinian-Israeli conflict in Gaza. Burns caused by WP usually result in death or disability. The purpose of the work is to analyze and summarize the data of the scientific literature on the medical consequences and treatment of lesions caused using ammunition with WP. Materials and methods. For the analysis, we used available scientific publications describing the consequences of WP burns received during hostilities. The method of analysis is descriptive. The following tasks were solved: the properties of WP as a damaging agent were studied; materials on the medical consequences of WP lesions and methods of treatment of such lesions were summarized. Discussion of the results. WP is highly reactive, highly toxic and ignites in air as early as 35°C. The severity of WP lesions is the result of both the thermal and chemical effects of combustion. Fatalities among humans from WP burns have occurred involving less than 10% of the total body surface area. Burns caused by WP heal more slowly than thermal burns. WP penetrates deeply through the fatty subcutaneous tissue. Therefore, the burns are full-thick, necrotic. The absorbed WP acts as a cellular poison and causes damage to the central nervous system, liver, kidneys, myocardium, and other organs. Any WP particles trapped in the wound may re-ignite. Conclusion. At the pre-hospital stage, the first thing to do is to wash off the wounds with cool water and remove the pieces of WP that have fallen into the skin with forceps. The light from the UV lamp can help to visualize the small particles of WP. Cleaning exfoliated skin and removing visible WP particles from the skin are critical methods for limiting wound severity and systemic WP absorption. It is advisable to excise the burned area within an hour after the lesion and repeat surgical procedures until all phosphorus particles have been removed; to control during the first 48 hours for the content of calcium and phosphorus in the blood serum with appropriate correction. In the future, skin grafting and treatment with allogeneic mesenchymal stem cells are advisable.

Segurança e eficácia das células-tronco mesenquimais alogênicas da medula óssea para o tratamento da leucopenia canina induzida pela infecção por parvovírus canino

ABSTRACT: This study aims to establish a therapy strategy for canine leukopenia induced by canine parvovirus (CPV) infection through intravenous infusion of allogeneic bone marrow mesenchymal stem cells (BMMSCs) and to evaluate the therapeutic effect of BMMSCs on canine parvovirus. Forty healthy 2-month-old dogs were randomly divided into four groups including the BMMSC treatment group (A), conventional treatment group (B), CPV infection group (C), and a normal control group (D). Then the A, B, and C groups were orally infected with CPV (103.25 TCID50/mL) at 1mL/kg, and the D group received the same dose of saline. After the onset of infection, Group A received mesenchymal stem cells (MSCs) and rehydration as the treatment; Group B was treated with anti-inflammatory therapeutics and rehydration; and Group C and D were injected with the same dose of physiological saline. The level of leukocytes rebounded significantly after the treatment with BMMSCs and returned to reference numbers on Day 3 after treatment, which was significantly higher than that in the conventional treatment group. The concentrations of IL-2 and IFN-α were gradually increased during the treatment, and the BMMSC treatment group exhibited significantly higher IL-2 and IFN-α concentrations than the conventional treatment group on Days 3 and 4. The expression of the virus in the blood gradually decreased during the treatment, and the BMMSC treatment group displayed a faster decrease than the conventional treatment group. These results showed the advantages of BMMSC treatment over conventional treatment. This study provides a new BMMSC treatment strategy for canine leukopenia induced by CPV infection and reveals the mechanism by which BMMSC increases leukocytes after CPV infection.

Wharton's jelly mesenchymal stem cells transplantation for critical limb ischemia in patients with type 2 diabetes mellitus: a preliminary report of phase I clinical trial.

Peripheral artery disease (PAD) affects more than 230 million people worldwide, with approximately 11% of patients presenting with advanced-stage PAD or critical limb ischemia (CLI). To avoid or delay amputation, particularly in no-option CLI patients with infeasible or ineffective revascularization, new treatment strategies such as regenerative therapies should be developed. Mesenchymal stem cells (MSCs) are the most popular cell source in regenerative therapies. They possess significant characteristics such as angiogenic, anti-inflammatory, and immunomodulatory activities, which encourage their application in different diseases. This phase I clinical trial reports the safety, feasibility, and probable efficacy of the intramuscular administration of allogeneic Wharton's jelly-derived MSCs (WJ-MSCs) in type 2 diabetes patients with CLI. Out of six screened patients with CLI, five patients were administered WJ-MSCs into the gastrocnemius, soleus, and the proximal part of the tibialis anterior muscles of the ischemic lower limb. The safety of WJ-MSCs injection was considered a primary outcome. Secondary endpoints included wound healing, the presence of pulse at the disease site, the absence of amputation, and improvement in visual analogue scale (VAS), pain-free walking time, and foot and ankle disability index (FADI). No patient experienced adverse events and foot or even toe amputation during the 6-month follow-up. Six months after the intervention, there were a significantly lower VAS score and significantly higher pain-free walking time and FADI score than the baseline, but no statistically significant difference was seen between other time points. In conclusion, allogeneic WJ-MSC transplantation in patients with CLI seems to be safe and effective.

Biomimetic vascularized adipose-derived mesenchymal stem cells bone-periosteum graft enhances angiogenesis and osteogenesis in a male rabbit spine fusion model.

Several artificial bone grafts have been developed but fail to achieve anticipated osteogenesis due to their insufficient neovascularization capacity and periosteum support. This study aimed to develop a vascularized bone-periosteum construct (VBPC) to provide better angiogenesis and osteogenesis for bone regeneration. A total of 24 male New Zealand white rabbits were divided into four groups according to the experimental materials. Allogenic adipose-derived mesenchymal stem cells (AMSCs) were cultured and seeded evenly in the collagen/chitosan sheet to form cell sheet as periosteum. Simultaneously, allogenic AMSCs were seeded onto alginate beads and were cultured to differentiate to endothelial-like cells to form vascularized bone construct (VBC). The cell sheet was wrapped onto VBC to create a vascularized bone-periosteum construct (VBPC). Four different experimental materials - acellular construct, VBC, non-vascularized bone-periosteum construct, and VBPC - were then implanted in bilateral L4-L5 intertransverse space. At 12 weeks post-surgery, the bone-forming capacities were determined by CT, biomechanical testing, histology, and immunohistochemistry staining analyses. At 12 weeks, the VBPC group significantly increased new bone formation volume compared with the other groups. Biomechanical testing demonstrated higher torque strength in the VBPC group. Notably, the haematoxylin and eosin, Masson's trichrome, and immunohistochemistry-stained histological results revealed that VBPC promoted neovascularization and new bone formation in the spine fusion areas. The tissue-engineered VBPC showed great capability in promoting angiogenesis and osteogenesis in vivo. It may provide a novel approach to create a superior blood supply and nutritional environment to overcome the deficits of current artificial bone graft substitutes.