Mesenchymal Stem/Stromal Cells Derived from Human and Animal Perinatal Tissues-Origins, Characteristics, Signaling Pathways, and Clinical Trials.

Mesenchymal stem/stromal cells (MSCs) are currently one of the most extensively researched fields due to their promising opportunity for use in regenerative medicine. There are many sources of MSCs, of which cells of perinatal origin appear to be an invaluable pool. Compared to embryonic stem cells, they are devoid of ethical conflicts because they are derived from tissues surrounding the fetus and can be safely recovered from medical waste after delivery. Additionally, perinatal MSCs exhibit better self-renewal and differentiation properties than those derived from adult tissues. It is important to consider the anatomy of perinatal tissues and the general description of MSCs, including their isolation, differentiation, and characterization of different types of perinatal MSCs from both animals and humans (placenta, umbilical cord, amniotic fluid). Ultimately, signaling pathways are essential to consider regarding the clinical applications of MSCs. It is important to consider the origin of these cells, referring to the anatomical structure of the organs of origin, when describing the general and specific characteristics of the different types of MSCs as well as the pathways involved in differentiation.

Three-dimensional human placenta-like bud synthesized from induced pluripotent stem cells.

Placental dysfunction is related to the pathogenesis of preeclampsia and fetal growth restriction, but there is no effective treatment for it. Recently, various functional three-dimensional organs have been generated from human induced-pluripotent cells (iPSCs), and the transplantation of these iPSCs-derived organs has alleviated liver failure or diabetes mellitus in mouse models. Here we successfully generated a three-dimensional placental organ bud from human iPSCs. The iPSCs differentiated into various lineages of trophoblasts such as cytotrophoblast-like, syncytiotrophoblast-like, and extravillous trophoblast-like cells, forming organized layers in the bud. Placental buds were transplanted to the murine uterus, where 22% of the buds were successfully engrafted. These iPSC-derived placental organ buds could serve as a new model for the study of placental function and pathology.

Human placental-derived stem cell therapy ameliorates experimental necrotizing enterocolitis.

Necrotizing enterocolitis (NEC), a life-threatening intestinal disease, is becoming a larger proportionate cause of morbidity and mortality in premature infants. To date, therapeutic options remain elusive. Based on recent cell therapy studies, we investigated the effect of a human placental-derived stem cell (hPSC) therapy on intestinal damage in an experimental NEC rat pup model. NEC was induced in newborn Sprague-Dawley rat pups for 4 days via formula feeding, hypoxia, and LPS. NEC pups received intraperitoneal (ip) injections of either saline or hPSC (NEC-hPSC) at 32 and 56 h into NEC induction. At 4 days, intestinal macroscopic and histological damage, epithelial cell composition, and inflammatory marker expression of the ileum were assessed. Breastfed (BF) littermates were used as controls. NEC pups developed significant bowel dilation and fragility in the ileum. Further, NEC induced loss of normal villi-crypt morphology, disruption of epithelial proliferation and apoptosis, and loss of critical progenitor/stem cell and Paneth cell populations in the crypt. hPSC treatment improved macroscopic intestinal health with reduced ileal dilation and fragility. Histologically, hPSC administration had a significant reparative effect on the villi-crypt morphology and epithelium. In addition to a trend of decreased inflammatory marker expression, hPSC-NEC pups had increased epithelial proliferation and decreased apoptosis when compared with NEC littermates. Further, the intestinal stem cell and crypt niche that include Paneth cells, SOX9+ cells, and LGR5+ stem cells were restored with hPSC therapy. Together, these data demonstrate hPSC can promote epithelial healing of NEC intestinal damage.NEW & NOTEWORTHY These studies demonstrate a human placental-derived stem cell (hPSC) therapeutic strategy for necrotizing enterocolitis (NEC). In an experimental model of NEC, hPSC administration improved macroscopic intestinal health, ameliorated epithelial morphology, and supported the intestinal stem cell niche. Our data suggest that hPSC are a potential therapeutic approach to attenuate established intestinal NEC damage. Further, we show hPSC are a novel research tool that can be utilized to elucidate critical neonatal repair mechanisms to overcome NEC.

Placental Mitochondria Therapy for Cerebral Ischemia-Reperfusion Injury in Mice.

BACKGROUND AND PURPOSE: There is an urgent need to develop adjunct therapies that can be added onto reperfusion for acute ischemic stroke. Recently, mitochondrial transplantation has emerged as a promising therapeutic approach for boosting brain tissue protection. In this proof-of-concept study, we investigate the feasibility of using placenta as a source for mitochondrial transplantation in a mouse model of transient focal cerebral ischemia-reperfusion. METHODS: Mitochondria-enriched fractions were isolated from cryopreserved mouse placenta. Mitochondrial purity and JC1 membrane potentials were assessed by flow cytometry. Adenosine triphosphate and mitochondrial proteins were measured by luminescence intensity and western blot, respectively. Therapeutic efficacy of mitochondrial fractions was assessed in a mouse model of transient focal cerebral ischemia-reperfusion. RESULTS: Flow cytometry analysis demonstrated that about 87% of placental mitochondria were viable and maintained JC1 membrane potentials after isolation. Placental mitochondrial fractions contained adenosine triphosphate equivalent to mitochondrial fractions isolated from skeletal muscle and brown fat tissue. Normalized mitochondrial antioxidant enzymes (glutathione reductase, MnSOD [manganese superoxide dismutase]) and HSP70 (heat shock protein 70) were highly preserved in placental mitochondrial fractions. Treatment with placental mitochondrial fractions immediately after reperfusion significantly decreased infarction after focal cerebral ischemia in mice. CONCLUSIONS: Cryopreserved placenta can be a feasible source for viable mitochondrial isolation. Transplantation with placental mitochondria may amplify beneficial effects of reperfusion in stroke.

Placental membrane grafts for urethral replacement in a rabbit model: a pilot study.

PURPOSE: Several graft materials are available for use in the treatment of urethral stricture disease. Placental membrane is being used in a variety of settings as a graft in wound healing and tissue repair. We aim to evaluate the effect of implanting decellularized human placental membrane into rabbit urethras. METHODS: Dorsal onlay graft urethroplasty using prepared human placental membrane was performed in 10 New Zealand White rabbits (Oryctolagus cuniculus). After 3 months, the rabbits underwent cystourethroscopy to evaluate urethral patency. The rabbits were then euthanized and the urethras examined for pathological findings. RESULTS: All urethroplasties were performed without complication. There were no observed episodes of urinary retention, infection, or renal failure. Urethral patency was achieved in all rabbits 3 months postoperatively. Urothelial replacement of the placental membrane graft was observed in all rabbits without malignant transformation. CONCLUSION: Dorsal onlay urethroplasty using decellularized human placental membrane can safely be performed in a rabbit model. This pilot study demonstrated urothelial replacement of human placental membrane in the rabbit urethra without stricture formation. Placental membrane is a promising biomaterial for urethral reconstruction.

Prospective study of cryopreserved placental tissue wound matrix in the management of chronic venous leg ulcers.

OBJECTIVE: Chronic venous leg ulcers (VLUs) affect up to 2% of the general population, resulting in a significant socioeconomic burden. Placental tissue that contains mesenchymal stem cells and active growth factors has been shown to be beneficial in healing of chronic wounds. We compared the efficacy of a human viable wound matrix (hVWM) of cryopreserved placental tissue for the treatment of refractory VLUs with standard therapy. METHODS: This prospective single-center open-label single-arm study enrolled patients with Clinical, Etiology, Anatomy, and Pathophysiology clinical class C6 VLUs. The ulcers of all enrolled patients had failed to heal after a trial of standard therapy of at least 12 weeks, which included weekly multilayer compression therapy along with local wound care. The same patients subsequently received application of hVWM (Grafix; Osiris Therapeutics, Columbia, Md) every 1 to 2 weeks in addition to standard therapy. Healing with hVWM therapy was then compared with standard therapy, with each patient serving as his own control. RESULTS: There were 30 VLUs in 21 consecutive eligible patients who were enrolled in the study. All patients were men with an average age of 67 years (standard deviation [SD], ±10.8 years), and the average area of venous ulcers before hVWM initiation was 12.2 cm2 (SD, ±14.6 cm2; range, 3.3-12.3 cm2). Duplex ultrasound confirmed superficial or deep system venous reflux in all patients. Complete ulcer healing was achieved in 53% (16/30) of VLUs refractory to standard therapy after application of hVWM. There was a mean reduction in wound surface area by 79% (SD, ±27.3%; P < .001 compared with standard therapy) after a mean treatment time of 10.9 weeks. Eighty percent of VLUs were reduced in size by half compared with 25% with standard therapy (P < .001). The mean rate of reduction in ulcer area after hVWM applications was 1.69% per day vs 0.73% per day with standard therapy (P = .01). CONCLUSIONS: Cryopreserved placental tissue (hVWM) improves healing processes to achieve complete wound closure in a significant proportion of chronic VLUs refractory to standard therapy. Adjunctive therapy with hVWM provides superior healing rates in refractory VLUs.

Stage IV Perineal Pressure Ulcers in Immobile Patients Treated With Surgical Flap Closure Augmented With Cryopreserved Placental Membrane Containing Viable Cells.

INTRODUCTION: Surgical closure of late-stage pressure ulcers (PUs) poses challenges in the immobilized population due to the high rate of complications, including infection, dehiscence, and recurrence. Muscle flap closure is the standard treatment for chronic, late-stage (stage 4) PUs, characterized by the European Pressure Ulcer Advisory Panel and National Pressure Ulcer Advisory Panel as full-thickness tissue loss with exposure of bone, tendon, or muscle. OBJECTIVE: The aim of this study is to evaluate the outcomes associated with the use of a cryopreserved placental membrane containing viable cells (vCPM) graft for the augmentation of surgical flap closure in nonhealing perineal ulcers. MATERIALS AND METHODS: Four paraplegic patients (2 men, 2 women; average age, 61 years; range, 44-77 years) with stage IV PUs (ischial, gluteal, and sacral areas) with a mean duration of 4 years (range, 0.5-10 years) received muscle flap closure augmented with vCPM. Following surgical debridement, vCPM was placed between the wound bed and muscle flap closure prior to skin closure. Patients were kept offloaded in fluid-air beds for 6 weeks followed by a gradual return to mobilization. RESULTS: All 4 patients achieved complete wound closure in an average of 7 weeks (range, 6-8 weeks) without complications or recurrence. All patients demonstrated complete take of the muscle flap and maintained their closed wounds for an average follow-up of 12 months. CONCLUSIONS: Preliminary clinical results indicate vCPM supports surgical wound closure of chronic perineal PUs in immobile, high-risk patients. In an effort to decrease postoperative recovery time and reduce complications, vCPM may be beneficial for patients undergoing perineal muscle flap closure.

The Role of Placental Membrane Allografts in the Surgical Treatment of Tendinopathies.

Placental membrane grafts have long been used in the realms of wound care and ophthalmology to assist in the healing cascade. Recently, surgeons have started to implant placental membrane grafts in a wide variety of foot and ankle surgeries to take advantage of their many touted benefits. The application of placental membrane grafts for cases of lower extremity tendinopathy is detailed in this article.

Administration of placenta-derived mesenchymal stem cells counteracts a delayed anergic state following a transient induction of endogenous neurogenesis activity after global cerebral ischemia.

BACKGROUND: Global cerebral ischemia (GCI) is a major obstacle for cardiac arrest survival. Recent studies have suggested the possibility of mesenchymal stem cell (MSC) as a novel therapeutic option for GCI, but these results were limited to the neuroprotective effects of MSCs. Therefore, we aimed to investigate specific characteristics of neurogenesis after transient GCI, and to assess the effect of MSC on these characteristics. METHODS: Adult male Sprague-Dawley rats were subjected to 7 min of transient GCI and randomized into 7 groups: baseline, MSC, and control administered groups, to be analyzed at 2, 3, and 4 weeks after GCI, respectively. The same interventions were repeated for sham operated animals. Rats were euthanized at the designated time after GCI. RESULTS: A comparison of GCI and sham groups without MSC treatment, showed that the counts of bromodeoxyuridine (BrdU)- and doublecortin (DCX)-positive cells were significantly increased in the GCI group at 1 week after insult, but the trend was reversed at 3 weeks after insult. The counts of BrdU-, Ki67- and DCX-positive cells and the intensity of zinc translocator 3 (ZnT3) were all significantly higher in the MSC-treated group than those in the control group at 3 weeks after GCI. The count of NeuN-positive cells in the hippocampus was significantly increased in the MSC group at 4 weeks after GCI. CONCLUSIONS: GCI induces transient neurogenesis, followed by an anergic state. MSC may counteract this anergy of neurogenesis and result in an increase in intact neurons in later stages.

[Transplantation of human placenta mesenchymal stem cells reduces the level of inflammatory factors in lung tissues of mice with acute lung injury].

Objective To investigate the influence of human placenta mesenchymal stem cells (hPMSCs) on the expression levels of inflammatory factors in the lung tissues of lipopolysaccharide (LPS)-induced acute lung injury (ALI) mice. Methods Six-week-old healthy C57BL/6 male mice were randomly divided into control group, ALI model group and hPMSC-treated group, with 8 mice in each group. LPS was trickled in ALI model group by the trachea. The hPMSC-treated mice were injected with hPMSCs by tail vein at 12 hours after administration of LPS. The control group was managed with the corresponding dose of normal saline. The surface markers of hPMSCs were identificated by flow cytometry. The mice were sacrificed after 24 hours, and the histopathological changes of lung tissues were detected by HE staining before and after injection of hPMSCs. The dry to wet mass ratio (W/D) and the myeloperoxidase (MPO) activity of the lung tissues were tested, and the levels of inflammatory factors in bronchoalveolar lavage fluid (BALF) were measured by ELISA, including tumor necrosis factor (TNF-α), interleukin-1 (IL-1) and interleukin-6 (IL-6). Results Phenotypic identification of hPMSCs showed the positive expression for CD105, CD90 and CD73, but negative expression for CD14, CD34, CD45. Compared with the control group, the pathological injury of the lung tissues was severe in the ALI model group, the W/D ratio and MPO activity in the lung tissues increased, and the levels of TNF-α, IL-1, and IL-6 in the BALF were significantly elevated. Compared with the ALI model group, the treatment with hPMSCs alleviated the lung pathological damage, decreased the W/D ratio and MPO activity in the lung tissues, and down-regulated the expressions of TNF-α, IL-1 and IL-6 in the BALF. Conclusion Treatment with hPMSCs can reduce the levels of inflammatory cytokines in the lung tissues and attenuate LPS-induced ALI.

The Placenta: Applications in Orthopaedic Sports Medicine.

BACKGROUND: Placenta has a long history of use for treating burns and wounds. It is a rich source of collagen and other extracellular matrix proteins, tissue reparative growth factors, and stem cells, including mesenchymal stem cells (MSCs). Recent data show its therapeutic potential for orthopaedic sports medicine indications. PURPOSE: To provide orthopaedic surgeons with an anatomic description of the placenta, to characterize its cellular composition, and to review the literature reporting the use of placenta-derived cells and placental tissue allografts for orthopaedic sports medicine indications in animal models and in humans. STUDY DESIGN: Systematic review. METHODS: Using a total of 63 keyword combinations, the PubMed and MEDLINE databases were searched for published articles describing the use of placental cells and/or tissue for orthopaedic sports medicine indications. Information was collected on placental tissue type, indications, animal model, study design, treatment regimen, safety, and efficacy outcomes. Results were categorized by indication and subcategorized by animal model. RESULTS: Outcomes for 29 animal studies and 6 human studies reporting the use of placenta-derived therapeutics were generally positive; however, the placental tissue source, clinical indication, and administration route were highly variable across these studies. Fourteen animal studies described the use of placental tissue for tendon injuries, 13 studies for osteoarthritis or articular cartilage injuries, 3 for ligament injuries, and 1 for synovitis. Both placenta-derived culture-expanded cells (epithelial cells or MSCs) and placental tissue allografts were used in animal studies. In all human studies, commercial placental allografts were used. Five of 6 human studies examined the treatment of foot and ankle pathological conditions, and 1 studied the treatment of knee osteoarthritis. CONCLUSION: A review of the small number of reported studies revealed a high degree of variability in placental cell types, placental tissue preparation, routes of administration, and treatment regimens, which prohibits making any definitive conclusions. Currently, the clinical use of placenta is limited to only commercial placental tissue allografts, as there are no placenta-derived biological drugs approved for the treatment of orthopaedic sports medicine conditions in the United States. However, this review shows that the application of placental cells or tissue allografts appears to be safe and has potential to improve outcomes for orthopaedic sports medicine indications.

Open Surgical Implantation of a Viable Intact Cryopreserved Human Placental Membrane for the Treatment of Recalcitrant Plantar Fasciitis: Case Report With Greater than 2-Year Follow-Up Duration.

Plantar fasciitis is one of the most common conditions encountered by a podiatric physician. Although most individuals respond well to traditional conservative and surgical remedies, a portion of patients will exhaust all available treatment options and will experience ongoing pain that can ultimately affect their quality of life. There has been an increase in scientific and clinical research surrounding the medical use of human placental membranes (HPMs) and many of these point-of-care allografts are now commercially available. We present the case of a 53-year-old female with chronic plantar fasciitis for whom both conservative therapies and surgical treatments of 1 year's duration had previously failed. After open revision with implantation of viable intact cryopreserved human placental membrane (vCPM; Grafix®, Osiris Therapeutics, Inc., Columbia, MD), the patient was able to resume her full-work duty with minimal symptoms at the 12- and 24-month follow-up examinations. This case report highlights the use of HPMs as an adjunct approach in the treatment of recalcitrant plantar fasciitis and the need for continued research.

Phagocytosis of Extracellular Vesicles Extruded From the Placenta by Ovarian Cancer Cells Inhibits Growth of the Cancer Cells.

OBJECTIVE: Ovarian cancer is a common gynecological cancer, and parity is negatively associated with the incidence of this disease. This negative association is hypothesized to be due in part to shifting the balance of estrogen and progesterone toward more progesterone and reduced ovulation during pregnancy. However, studies suggested that parity is also associated with estrogen-independent gynecological cancers suggesting balance of hormones may not be the only protective factor. Extracellular vesicles (EVs) play an important role in cell-to-cell communication in physiological and pathological conditions. During pregnancy, large amounts of EVs are extruded from the placenta, and they seem to be involved in the remarkable adaptation of a woman's body to normal pregnancy. We hypothesized that EVs extruded from the placenta play a role in this protective effect. METHODS: Placental EVs were collected from first-trimester placentae, and cancer cell EVs were isolated from ovarian cancer cells. The EVs were exposed to ovarian cancer cells for 48 hours. The proliferation of cancer cells and the cell cycle were measured. In addition, phagocytosis of deported placental EVs by cancer cells was also measured. RESULTS: The proliferation of cancer cells was significantly reduced by treatment with placental EVs (P = 0.001, analysis of variance), but not EVs from monocytes (P = 0.195), compared with untreated cancer cells. Furthermore, placental EVs also prevented the proliferation of cancer cells induced by cancer cell-derived EVs (P = 0.001). This inhibition of proliferation of ovarian cancer cells was partially due to phagocytosis of placental EVs by cancer cells. Phagocytosis of placental EVs delayed progression through the cell cycle. Calreticulin, a phagocytic "eat me" signal carried by placental EVs significantly inhibited ovarian cancer growth (P = 0.001). CONCLUSIONS: Our data demonstrated that EVs extruded from the placenta prevented ovarian cancer cell growth by a mechanism that involved delaying progression of the cell cycle after phagocytosis of the EVs.

Modified acellular nerve-delivering PMSCs improve functional recovery in rats after complete spinal cord transection.

Due to the poor regeneration capacity of neurons and the inhibitory microenvironment, spontaneous regeneration in spinal cord injury (SCI) remains challenging. Tissue engineering is considered a promising approach for enhancing the regeneration of SCI by reconstructing the inherent structure and improving the microenvironment. In this study, the possibility of engineering a nerve complex, which is constructed by acellular nerve delivering placenta mesenchymal stem cells (PMSCs), was assessed for the recovery of a transected spinal cord. Modified acellular nerve grafts were developed, and PMSCs labeled with green fluorescent protein (GFP) were seeded on the graft to construct the engineered nerve complex. Then, the engineered nerve complex was implanted into a 2 mm-length transected gap of the spinal cord. Four weeks after the transplantation, numerous surviving PMSCs were observed in the lesion cavity by immunofluorescence staining. Moreover, co-localization between GFP and neurofilament-200 (NF200) and Neuronal Class III ß-Tubulin (Tuj1) was observed at the bridge interface. The PMSCs-graft group exhibited significant function improvement as evaluated by the Basso, Beattie and Bresnahan (BBB) locomotion score and footprint analysis. Eight weeks after surgery, the evoked response was restored in the PMSCs-graft group and numerous thick myelin sheathes were observed compared to that in the control groups. Collectively, our findings suggest that the nerve complex prepared by acellular nerve delivering PMSCs enhanced the structure and function regeneration of the spinal cord after SCI.

The use of viable cryopreserved placental tissue in the management of a chronic rectovaginal fistula.

We present a case of a chronic recurrent rectovaginal fistula that initially arose from complications of haemorrhoid surgery and had failed multiple prior surgical repairs. The fistula was successfully managed using viable cryopreserved placental tissue.

Open surgical implantation of a viable cryopreserved placental membrane after decompression and neurolysis of common peroneal nerve: a case series.

BACKGROUND: The purpose of this study is to report on the rehabilitative outcomes associated with common peroneal nerve (CPN) decompression and neurolysis revision when performed with open surgical implantation of a viable cryopreserved placental membrane (vCPM). METHODS: Seven patients who underwent secondary CPN decompression and neurolysis with open surgical implantation of a viable cryopreserved placental membrane (vCPM) after previously failed surgery without vCPM utilization were identified through a retrospective medical record review and outcomes were analyzed. Primary mechanism of injury, severity of symptoms at time of referral, pre-operative and post-operative evaluations on edema with ultrasound, Medical Research Council (MRC) scale for motor strength, range of motion, nerve conduction velocity (NCV), and electromyography (EMG) were analyzed. RESULTS: Five patients (71.4%) achieved full recovery of motor function MRC grade 5/5, and the remaining two patients achieved MRC grade 4/5. At the 7-month follow-up visit, NCV tests indicated improved conduction velocity and normal amplitude for all 7 patients, and all patients demonstrated proper gait pattern with a return to normal activities of daily living. There were no vCPM-related adverse events. CONCLUSIONS: The use of vCPM wrap as an adjunct to surgical repairs of CPN injuries may contribute to positive clinical outcomes.

Wound Closure in Smoking Peripheral Arterial Disease Patients With Treatment-Refractory Ulcerations: A 12-Month Follow-up Case Series.

Despite ongoing smoking cessation efforts and optimized perfusion, failed wound closure in the presence of peripheral arterial disease (PAD) and diabetes are common. A clinical effectiveness review was conducted in actively smoking diabetic patients diagnosed with PAD, treated with serial applications of a viable intact cryopreserved human placental membrane (vCPM) (Grafix, Osiris Therapeutics Inc, Columbia, MD) for recalcitrant lower extremity ulcerations (n = 6). More than half of the patients were not candidates for revascularization. Baseline vascular status in 5 of 6 lower-extremity wounds remained unchanged throughout the entire course of vCPM treatment. Daily cigarette consumption averaged 18 cigarettes per patient. Mean wound duration and mean surface area was 53 weeks and 4.6 cm2, respectively. Mean number of vCPM applications and time to closure was 7.0 grafts in 7.8 weeks. There were no wound-related infections or amputations and no vCPM-related adverse events. All 6 wounds remained closed at the 12-month follow-up visit. In conclusion, vCPM demonstrated clinically effective outcomes in 6 previously nonhealing ulcerations despite ongoing smoking habits in the presence of PAD and diabetes.

Viable intact cryopreserved human placental membrane for a non-surgical approach to closure in complex wounds.

OBJECTIVE: Advances in wound treatment have yielded successful approaches to complex wound closure through plastic surgery or other staged surgical methods. However, not all patients or wounds are candidates for such increasingly rigorous levels of interventions. The exploration of non-surgical treatment options that promote anatomical and functional tissue replacement on an outpatient basis without donor site morbidity is necessary to maximise opportunities for patient mobility and rehabilitation. The native components found in human placental membranes may offer alternative properties for the clinical management of these complex wounds. METHOD: A 10-month, single-centre effectiveness review was conducted on the clinical outcomes in patients (n=12) treated with Grafix, a viable intact cryopreserved human placental membrane (vCPM), for complex wounds characterised by exposed bone, tendon, muscle, or hardware. Wounds were treated with routine standard of care in addition to weekly grafting with a vCPM. RESULTS: The average baseline wound area and duration at presentation were 17.5 cm2 and 11.2 weeks. All twelve cases resulted in granulation over the exposed structures followed by complete wound re-epithelialisation without the concomitant use of negative pressure wound therapy, hyperbaric oxygen therapy, or surgical intervention. The mean 4-week percentage area reduction was 62.5 %. The mean time to closure was 10 weeks with a mean graft use of 8.1 grafts. Of the wounds seven (58%) presented with exposed tendon associated with an actively moving joint, the functional integrity of which was maintained with a return to the previous range of motion upon wound closure. CONCLUSION: These outcomes illustrate that vCPM is a clinically effective option in the non-surgical management of complex wounds in the outpatient setting, contributing to timely definitive closure without the risk of associated donor site morbidity. DECLARATION OF INTEREST: Kazu Suzuki, DPM, CWS is a member of the Speakers' Bureau at Osiris Therapeutics Inc., Georgina Michael and Yeabsera Tamire belong to the Department of Medical Affairs at Osiris Therapeutics Inc.

Human mesenchymal stem cells attenuate pulmonary hypertension induced by prenatal lipopolysaccharide treatment in rats.

Intra-amniotic injection of lipopolysaccharide (LPS) induces pulmonary hypertension in newborn rats. This study was designed to test whether human mesenchymal stem cells (MSCs) reduce pulmonary hypertension and alleviate cardiac hypertrophy in prenatal LPS-treated rats. Pregnant Sprague-Dawley rats were injected intraperitoneally with LPS (0.5 mg/kg per day) or untreated on gestational days 20 and 21. Human MSCs (3×10(5) cells and 1×10(6) cells) in 0.03 mL of normal saline (NS) were transplanted intratracheally on postnatal day 5. Four study groups were considered: normal, LPS+NS, LPS+MSCs (3×10(5) cells), and LPS+MSCs (1×10(6) cells). On postnatal day 14, lung and heart tissues were collected for measuring the arterial medial wall thickness (MWT) and ß-myosin heavy chain (ß-MHC) level as markers of pulmonary hypertension and cardiac hypertrophy, respectively. The LPS+NS group exhibited a significantly higher right ventricle (RV)/[left ventricle (LV)+ interventricular septum (IVS)] thickness ratio and MWT, a greater cardiomyocyte width, a greater number of cardiomyocyte nuclei per squared millimeter, and higher ß-MHC expression than those observed in the normal group. Human MSC transplantation (3×10(5) cells and 1×10(6) cells) in LPS-treated rats reduced MWT and the RV/(LV+IVS) thickness ratio to normal levels. This improvement in right ventricular hypertrophy was accompanied by a decrease in toll-like receptor 4 (TLR4), nuclear factor-κB, and tumor necrosis factor-α expression in the heart. Intratracheal human MSCs transplantation can attenuate pulmonary hypertension and right ventricular hypertrophy in prenatal LPS-treated rats; this attenuation may be associated with suppression of TLR4 expression via paracrine pathways.

Human placenta-derived multipotent mesenchymal stromal cells involved in placental angiogenesis via the PDGF-BB and STAT3 pathways.

We studied the smooth muscle cell differentiation capability of human placental multipotent mesenchymal stromal cells (hPMSCs) and identified how endothelial cells recruit hPMSCs participating in vessel formation. hPMSCs from term placentas were induced to differentiate into smooth muscle cells under induction conditions and different matrix substrates. We assessed endothelial cells from umbilical veins for platelet-derived growth factor (PDGF)-BB expression and to induce hPMSC PDGFR-beta and STAT3 activation. Endothelial cells were co-cultured with hPMSCs for in vitro angiogenesis. Cell differentiation ability was then further assessed by mouse placenta transplantation assay. hPMSCs can differentiate into smooth muscle cells; collagen type I and IV or laminin support this differentiation. Endothelial cells expressed significant levels of PDGF-BB and activated STAT3 transcriptional activity in hPMSCs. Endothelial cell-conditioned medium induced hPMSC migration, which was inhibited by STAT3 small interfering RNA transfection or by pretreatement with PDGFR-beta-blocking antibody but not by PDGFR-alpha-blocking antibody or isotype immunoglobulin G (IgG; P < 0.001). hPMSCs can incorporate into endothelial cells with tube formation and promote endothelial cells, forming capillary-like networks than endothelial cells alone (tube lengths: 12 024.1 ± 960.1 vs. 9404.2 ± 584.7 pixels; P < 0.001). Capillary-like networks were significantly reduced by hPMSCs pretreated with PDGFR-beta-blocking antibody but not by PDGFR-alpha-blocking antibody or isotype IgG (P < 0.001). Transplantation of hPMSCs into mouse placentas revealed incorporation of the hPMSCs into vessel walls, which expressed alpha-smooth muscle actin, calponin, and smooth muscle myosin (heavy chain) in vivo. In conclusion, endothelial cell-hPMSC interactions occur during vessel development of placenta. Placental endothelial cell-derived PDGF-BB recruits hPMSCs involved in vascular development via PDGFR-beta/STAT3 activation.