Transplantation of adipose-derived stem cells (ADSCs) is an emerging therapeutic option for addressing intractable diseases such as critical limb ischemia (CLI). Evidence suggests that therapeutic effects of ADSCs are primarily mediated through paracrine mechanisms rather than transdifferentiation. These secreted factors can be captured in conditioned medium (CM) and concentrated to prepare a therapeutic factor concentrate (TFC) composed of a cocktail of beneficial growth factors and cytokines that individually and in combination demonstrate disease-modifying effects. The ability of a TFC to promote reperfusion in a rabbit model of CLI was evaluated. A total of 27 adult female rabbits underwent surgery to induce ischemia in the left hindlimb. An additional five rabbits served as sham controls. One week after surgery, the ischemic limbs received intramuscular injections of either (1) placebo (control medium), (2) a low dose of TFC, or (3) a high dose of TFC. Limb perfusion was serially assessed with a Doppler probe. Blood samples were analyzed for growth factors and cytokines. Tissue was harvested postmortem on day 35 and assessed for capillary density by immunohistochemistry. At 1 month after treatment, tissue perfusion in ischemic limbs treated with a high dose of TFC was almost double (p < 0.05) that of the placebo group [58.8 ± 23 relative perfusion units (RPU) vs. 30.7 ± 13.6 RPU; mean ± SD]. This effect was correlated with greater capillary density in the affected tissues and with transiently higher serum levels of the angiogenic and prosurvival factors vascular endothelial growth factor (VEGF) and hepatocyte growth factor (HGF). The conclusions from this study are that a single bolus administration of TFC demonstrated robust effects for promoting tissue reperfusion in a rabbit model of CLI and that a possible mechanism of revascularization was promotion of angiogenesis by TFC. Results of this study demonstrate that TFC represents a potent therapeutic cocktail for patients with CLI, many of whom are at risk for amputation of the affected limb.

Backround Deep skin burn injuries, especially those on the face, hands, feet, genitalia and perineum represent significant therapeutic challenges. Autologous dermo-epidermal skin grafts (DESG) have become standard of care for treating deep burns. Additionally, human autologous thrombin activated autologous platelet concentrate (APC) has gained acceptance in the setting of wounds. While each of these interventions has been independently shown to accelerate healing, the combination of the two has never been evaluated. We hypothesized that the addition of platelets (source of growth factors and inhibitors necessary for tissue repair) to the DESG (source of progenitor cells and of tissue proteases necessary for spatial and temporal control of growth regulators released from platelets) would create the optimal environment for the reciprocal interaction of cells within the healing tissues. Methods We used clinical examination (digital photography), standardised scales for evaluating pain and scarring, in combination with blood perfusion (laser Doppler imaging), as well as molecular and laboratory analyses. Results We show for the first time that the combination of APC and DESG leads to earlier relief of pain, and decreased use of analgesics, antipruritics and orthotic devices. Most importantly, this treatment is associated with earlier discharges from hospital and significant cost savings. Conclusions Our findings indicate that DESG engraftment is facilitated by the local addition of platelets and by systemic thrombocytosis. This local interaction leads to the physiological revascularization at 1–3 months. We observed significant elevation of circulating platelets in early stages of engraftment (1–7 days), which normalized over the subsequent 7 and 90 days.

BackgroundParacrine factors secreted by adipose-derived stem cells can be captured, fractionated, and concentrated to produce therapeutic factor concentrate (TFC). The present study examined whether TFC effects could be enhanced by combining TFC with a biological matrix to provide sustained release of factors in the target region.Material/MethodsUnilateral hind limb ischemia was induced in rabbits. Ischemic limbs were injected with either placebo control, TFC, micronized small intestinal submucosa tissue (SIS), or TFC absorbed to SIS. Blood flow in both limbs was assessed with laser Doppler perfusion imaging. Tissues harvested at Day 48 were assessed immunohistochemically for vessel density; in situ hybridization and quantitative real-time PCR were employed to determine miR-126 expression.ResultsLDP ratios were significantly elevated, compared to placebo control, on day 28 in all treatment groups (p=0.0816, p=0.0543, p=0.0639, for groups 2–4, respectively) and on day 36 in the TFC group (p=0.0866). This effect correlated with capillary density in the SIS and TFC+SIS groups (p=0.0093 and p=0.0054, respectively, compared to placebo). A correlation was observed between miR-126 levels and LDP levels at 48 days in SIS and TFC+SIS groups.ConclusionsA single bolus administration of TFC and SIS had early, transient effects on reperfusion and promotion of ischemia repair. The effects were not additive. We also discovered that TFC modulated miR-126 levels that were expressed in cell types other than endothelial cells. These data suggested that TFC, alone or in combination with SIS, may be a potent therapy for patients with CLI that are at risk of amputation.

BackgroundHeart failure (HF) is a major chronic illness and results in high morbidity and mortality. The most frequent cause of HF with reduced ejection fraction (HFREF) is coronary artery disease (CAD). Although revascularisation of ischemic myocardium lead to improvements in myocardial contractility and systolic function, it cannnot restore the viability of the already necrotic myocardium.Methods/designThe aim of our prospective randomised study is to assess the efficacy of the retrograde application of non-selected bone marrow autologous cells concentrate (BMAC) in patients with HFREF of ischemic aetiology. The evaluated preparation is concentrated BMAC, obtained using Harvest SmartPReP2 (Harvest Technologies, Plymouth, MA, USA). The study population will be a total of 40 patients with established CAD, systolic dysfunction with LV EF of ≤40% and HF in the NYHA class 3. Patients have been on standard HF therapy for 3 months and in a stabilised state for at least 1 month, before enrolling in the clinical study. Patients will be randomised 1:1 to either retrograde BMAC administration via coronary sinus or standard HF therapy. The primary end-points (left ventricular end-systolic and end-diastolic diameters [LVESd/EDd] and volumes [LVESV/EDV] and left ventricular ejection fraction [LV EF]) will be assessed by magnetic resonance imaging. The follow-up period will be 12 month.DiscussionThe application of bone marrow stem cells into affected areas of the myocardium seems to be a promising treatment of ischemic cardiomyopathy.The Harvest BMAC contains the entire population of nuclear cells from bone marrow aspirates together with platelets. The presence of both platelets and additional granulocytes can have a positive effect on the neovascularisation potential of the resulting concentrate. Our assumption is that retrograde administration on non-selected BMAC via coronary sinus, due to the content of platelets and growth factors, might improve left ventricular function and parameters compared to standard HF therapy. Furthermore, it will be associated with improved exercise tolerance in the six-minute corridor walk test and an improvement in the life quality of patients without increasing the incidence of severe ventricular arrythmias.Trial registration(ClinicalTrials.gov; https://clinicaltrials.gov; NCT03372954).

Based on our results, we believe that treatment with ASC-CM has the potential to accelerate the healing process in ischemic tissues in the rabbit model of CLI. The whole healing process was accompanied by miR-126 tissue expression. C-peptide could be used to monitor the course of the tissue healing process.