A Comparative In Vitro and In Vivo Study of Osteogenicity by Using Two Biomaterials and Two Human Mesenchymal Stem Cell Subtypes.

Background: Bone repair induced by stem cells and biomaterials may represent an alternative to autologous bone grafting. Mesenchymal stromal/stem cells (MSCs), easily accessible in every human, are prototypical cells that can be tested, alone or with a biomaterial, for creating new osteoblasts. The aim of this study was to compare the efficiency of two biomaterials-biphasic calcium phosphate (BCP) and bioactive glass (BG)-when loaded with either adult bone marrow mesenchymal stem cells (BMMSCs) or newborn nasal ecto-mesenchymal stem cells (NE-MSCs), the latter being collected for further repair of lip cleft-associated bone loss. Materials and Methods: BMMSCs were collected from two adults and NE-MSCs from two newborn infants. An in vitro study was performed in order to determine the best experimental conditions for adhesion, viability, proliferation and osteoblastic differentiation on BCP or BG granules. Bone-associated morphological changes and gene expression modifications were quantified using histological and molecular techniques. The in vivo study was based on the subcutaneous implantation in nude mice of the biomaterials, loaded or not with one of the two cell types. Eight weeks after, bone formation was assessed using histological and electron microscopy techniques. Results: Both cell types-BMMSC and NE-MSC-display the typical stem cell surface markers-CD73+, CD90+, CD105+, nestin - and exhibit the MSC-associated osteogenic, chondrogenic and adipogenic multipotency. NE-MSCs produce less collagen and alkaline phosphatase than BMMSCs. At the transcript level, NE-MSCs express more abundantly three genes coding for bone sialoprotein, osteocalcin and osteopontin while BMMSCs produce extra copies of RunX2. BMMSCs and NE-MSCs adhere and survive on BCP and BG. In vivo experiments reveal that bone formation is only observed with BMMSCs transplanted on BCP biomaterial. Conclusion: Although belonging to the same superfamily of mesenchymal stem cells, BMMSCs and NE-MSCs exhibit striking differences, in vitro and in vivo. For future clinical applications, the association of BMMSCs with BCP biomaterial seems to be the most promising.

Long-term follow-up after autologous adipose-derived stromal vascular fraction injection into fingers in systemic sclerosis patients.

INTRODUCTION: Hand involvement confers a substantial handicap in work and daily activities in patients with Systemic sclerosis (SSc). Autologous adipose-derived stromal vascular fraction is as an easily accessible source of cells with regenerative effects. We previously performed a phase I open-label clinical trial (NTC01813279) assessing the safety of subcutaneous injection of autologous adipose-derived stromal vascular fraction. Six and 12-month data have been reported. As patients were followed in our medical centre, we report their longer-term outcome beyond the end of the trial. PATIENTS AND METHOD: Twelve females, mean age 54.5±10.3 years, initially enrolled in the clinical trial were assessed during a scheduled medical care, which took place between 22 and 30months after treatment. RESULTS: Multiple patient-reported outcomes showed sustained improvement, in comparison with the assessment performed just before surgery: 62.5% in the Cochin Hand Function Scale, 51.1% in the Scleroderma Health Assessment Questionnaire, 33.1% in hand pain, and 88.3% in the Raynaud Condition Score. A decrease in the number of digital ulcers number was noted. Mobility, strength and fibrosis of the hand also showed improvement. None of the 8 patients who had previously received iloprost infusion required new infusion. CONCLUSION: Despite the limits of an open label study, the data are in favour of the long-term safety of the adipose-derived stromal vascular fraction injection. Two randomized double blind, placebo-controlled trials of this therapeutic agent are ongoing in the USA (NCT02396238) and in France (NCT02558543) and will help determine the place of this innovative therapy for SSc patients.

DEPA classification: a proposal for standardising PRP use and a retrospective application of available devices.

BACKGROUND/AIM: Significant biological differences in platelet-rich plasma (PRP) preparations have been highlighted and could explain the large variability in the clinical benefit of PRP reported in the literature. The scientific community now recommends the use of classification for PRP injection; however, these classifications are focused on platelet and leucocyte concentrations. This presents the disadvantages of (1) not taking into account the final volume of the preparation; (2) omitting the presence of red blood cells in PRP and (3) not assessing the efficiency of production. METHODS: On the basis of standards classically used in the Cell Therapy field, we propose the DEPA (Dose of injected platelets, Efficiency of production, Purity of the PRP, Activation of the PRP) classification to extend the characterisation of the injected PRP preparation. We retrospectively applied this classification on 20 PRP preparations for which biological characteristics were available in the literature. RESULTS: Dose of injected platelets varies from 0.21 to 5.43 billion, corresponding to a 25-fold increase. Only a Magellan device was able to obtain an A score for this parameter. Assessments of the efficiency of production reveal that no device is able to recover more than 90% of platelets from the blood. Purity of the preparation reveals that a majority of the preparations are contaminated by red blood cells as only three devices reach an A score for this parameter, corresponding to a percentage of platelets compared with red blood cells and leucocytes over 90%. CONCLUSIONS: These findings should provide significant help to clinicians in selecting a system that meets their specific needs for a given indication.

Lenalidomide normalizes tumor vessels in colorectal cancer improving chemotherapy activity.

BACKGROUND: Angiogenesis inhibition is a promising approach for treating metastatic colorectal cancer (mCRC). Recent evidences support the seemingly counterintuitive ability of certain antiangiogenic drugs to promote normalization of residual tumor vessels with important clinical implications. Lenalidomide is an oral drug with immune-modulatory and anti-angiogenic activity against selected hematologic malignancies but as yet little is known regarding its effectiveness for solid tumors. The aim of this study was to determine whether lenalidomide can normalize colorectal cancer neo-vessels in vivo, thus reducing tumor hypoxia and improving the benefit of chemotherapy. METHODS: We set up a tumorgraft model with NOD/SCID mice implanted with a patient-derived colorectal cancer liver metastasis. The mice were treated with oral lenalidomide (50 mg/Kg/day for 28 days), intraperitoneal 5-fluorouracil (5FU) (20 mg/Kg twice weekly for 3 weeks), combination (combo) of lenalidomide and 5FU or irrelevant vehicle. We assessed tumor vessel density (CD146), pericyte coverage (NG2; alphaSMA), in vivo perfusion capability of residual vessels (lectin distribution essay), hypoxic areas (HP2-100 Hypoxyprobe) and antitumor activity in vivo and in vitro. RESULTS: Treatment with lenalidomide reduced tumor vessel density (p = 0.0001) and enhanced mature pericyte coverage of residual vessels (p = 0.002). Perfusion capability of tumor vessels was enhanced in mice treated with lenalidomide compared to controls (p = 0.004). Accordingly, lenalidomide reduced hypoxic tumor areas (p = 0.002) and enhanced the antitumor activity of 5FU in vivo. The combo treatment delayed tumor growth (p = 0.01) and significantly reduced the Ki67 index (p = 0.0002). Lenalidomide alone did not demonstrate antitumor activity compared to untreated controls in vivo or against 4 different mCRC cell lines in vitro. CONCLUSIONS: We provide the first evidence of tumor vessel normalization and hypoxia reduction induced by lenalidomide in mCRC in vivo. This effect, seemingly counterintuitive for an antiangiogenic compound, translates into indirect antitumor activity thus enhancing the therapeutic index of chemotherapy. Our findings suggest that further research should be carried out on synergism between lenalidomide and conventional therapies for treating solid tumors that might benefit from tumor vasculature normalization.

Standardization of platelet-derived microparticle counting using calibrated beads and a Cytomics FC500 routine flow cytometer: a first step towards multicenter studies?

BACKGROUND: Platelet microparticles (PMPs) have proved useful to identify patients with vascular risk. However, PMP counting, which is currently done by flow cytometry (FCM), needs to be standardized. OBJECTIVES: The objectives were (i) to standardize FCM settings for PMP counts on a routine instrument (Cytomics FC500) using size-calibrated fluorescent beads; (ii) to determine intra-instrument and inter-instrument reproducibility; and (iii) to establish PMP values in healthy subjects. METHODS: Using a blend of size-calibrated fluorescent beads (0.5 and 0.9 mum) in a fixed numerical ratio (Megamix), we gated PMPs in a restricted size window. To test intra-instrument and inter-instrument reproducibility, annexin V and CD41 coexpression were used to count PMPs in frozen aliquots of the same platelet-free plasma (PFP) over 4 months and in PFP from 10 healthy subjects on three independent flow cytometers. RESULTS: This calibrated-bead strategy allowed full long-term control of the FCM-based microparticle protocol and reproducible PMP counts over time [coefficient of variation (CV) < 10%]. Optimal settings were easily transferred from one instrument to another, using Megamix as a stable template. Similar PMP counts (CV < 12%) were obtained using the three instruments. With such a standardized FCM protocol, PMP values were established in healthy subjects (n = 60) with significantly higher levels in women than in men [median (1st quartile to 3rd quartile): 1775 microL(-1) (1014-3039 microL(-1)) vs. 656 microL(-1) (407-962 microL(-1))]. CONCLUSIONS: The present strategy provides a new option for PMP count standardization and thus opens the way for multicenter studies.

IgM in saliva from allergic children.

In this study the authors investigated the relationship between secretory IgA levels and the appearance of a compensatory mechanism, through IgM action in allergic children.