Functionalized PCL/HA nanocomposites as microporous membranes for bone regeneration

In the present work, microporous membranes based on poly(ε-caprolactone) (PCL) and PCL functionalized with amine (PCL-DMAEA) or anhydride groups (PCL-MAGMA) were realized by solvent-non solvent phase inversion and proposed for use in Guided Tissue Regeneration (GTR). Nanowhiskers of hydroxyapatite (HA) were also incorporated in the polymer matrix to realize nanocomposite membranes. Scanning Electron Microscopy (SEM) showed improved interfacial adhesion with HA for functionalized polymers, and highlighted substantial differences in the porosity. A relationship between the developed porous structure of the membrane and the chemical nature of grafted groups was proposed. Compared to virgin PCL, hydrophilicity increases for functionalized PCL, while the addition of HA influences significantly the hydrophilic characteristics only in the case of virgin polymer. A significant increase of in vitro degradation rate was found for PCL-MAGMA based membranes, and at lower extent of PCL-DMAEA membranes. The novel materials were investigated regarding their potential as support for cell growth in bone repair using multipotent mesenchymal stromal cells (MSC) as a model. MSC plated onto the various membranes were analyzed in terms of adhesion, proliferation and osteogenic capacity that resulted to be related to chemical as well as porous structure. In particular, PCL-DMAEA and the relative nanocomposite membranes are the most promising in terms of cell-biomaterial interactions

The Tyrosine Kinase Inhibitor Dasatinib Induces a Marked Adipogenic Differentiation of Human Multipotent Mesenchymal Stromal Cells

BACKGROUND: The introduction of specific BCR-ABL inhibitors in chronic myelogenous leukemia therapy has entirely mutated the prognosis of this hematologic cancer from being a fatal disorder to becoming a chronic disease. Due to the probable long lasting treatment with tyrosine-kinase inhibitors (TKIs), the knowledge of their effects on normal cells is of pivotal importance. DESIGN AND METHODS: We investigated the effects of dasatinib treatment on human bone marrow-derived mesenchymal stromal cells (MSCs). RESULTS: Our findings demonstrate, for the first time, that dasatinib induces MSCs adipocytic differentiation. Particularly, when the TKI is added to the medium inducing osteogenic differentiation, a high MSCs percentage acquires adipocytic morphology and overexpresses adipocytic specific genes, including PPARγ, CEBPα, LPL and SREBP1c. Dasatinib also inhibits the activity of alkaline phosphatase, an osteogenic marker, and remarkably reduces matrix mineralization. The increase of PPARγ is also confirmed at protein level. The component of osteogenic medium required for dasatinib-induced adipogenesis is dexamethasone. Intriguingly, the increase of adipocytic markers is also observed in MSCs treated with dasatinib alone. The TKI effect is phenotype-specific, since fibroblasts do not undergo adipocytic differentiation or PPARγ increase. CONCLUSIONS: Our data demonstrate that dasatinib treatment affects bone marrow MSCs commitment and suggest that TKIs therapy might modify normal phenotypes with potential significant negative consequences

Continuous hydrogen production by immobilized cultures of Thermotoga neapolitana on an acrylic hydrogel with pH-buffering properties

This communication reports on the continuous biohydrogen production by Thermotoga neapolitana cells immobilized on a stable cationic hydrogel bearing amine groups. This hydrogel was designed to perform two functional activities: to promote adhesion of T. neapolitana cells, and to buffer pH changes in the bacterial cultures. Repeated fed-batch cultures showed an average hydrogen production rate and yield of 50.6 mL L−1 h−1 and 3.3 mol H2/mol glucose, respectively. To the best of our knowledge, this is the first report detailing the immobilization of this bacterial strain on a polymeric support

Abstract LB-229: Treatment of advanced cancer patients with a newest poly-epitope peptide vaccine to the thymidylate synthase(TSPP): a phase Ib (TSPP/VAC1) trial

Abstract Background TSPP is a poly-epitope peptide vaccine to the thymidylate syntase (TS) an enzyme commonly over-expressed in replicating cancer cells and recognized as a major target of fluoropyrimidines. TSPP showed immunological and anticancer activity in preclinical models, thus in the present study we investigated its safety and immunobiological activity in advanced cancer patients. This study was designed to identify TSPP Maximum Tolerated Dose (MTD) and Optimal Biological Dose (OBD) when used alone (arm A) or in combination with GM-CSF and IL-2 according to the IG-1 regimen (arm B). Patients and methods TSPP/VAC-1 (Eudract 2009-016897-33) is a monocentric phase Ib trial including 21 pretreated advanced cancer patients (12 in arm A and 9 in arm B) enrolled between April and October 2011 (12 with colorectal, 1 with breast, 1 with gastric, 1 with biliary tract and 6 with non small cell lung cancer). All patients presented a good performance status (ECOG ≤ 1). Each patient received every 3 weeks a sc administration of TSPP diluted in motanide ISA720 (1:1) at the dosage of 100 µg (6 patients), 200 µg (6 patients), and 300 µg (9 patients). Patients enrolled in arm B also received daily sc GM-CSF (100 µg) from day 1 to 5 and sc IL-2 (0.5 MIU) bid from day 6 to 15. Results No life-threatening adverse events were recorded; 1 case of grade 3 hypothyroidism (arm B), 4 cases of poly-articular arthropaty (arm A), and 4 cases of conjuntivitis (arm A) were observed. In arm B, cytokine-related flu-like syndrome, nausea, vomiting, and dyarrhea were commonly reported. An IFN-gamma ELISPOT assay revealed an increase in TS specific CTL precursors in 5 patients in arm A and 2 in arm B. It was also observed an increase in terminal effector memory and central memory T cells in the peripheral blood in both arms. Patients enrolled in arm A showed a significant decline in peripheral immune-regulatory (CD4+CD25hi+FoxP3+) T cells (baseline vs 3 vaccinations (B vs III): 3.8 vs 1.7 %; p= 0.041) and inhibitory myeloid cells (CD11c+CD15+) [Baseline (Bs) vs III vaccinations (Vc): 5.09 vs 1.02%; p= 0.05] associated to an increase in anti-proteinase III (Bs vs III Vs:0.48 vs 1.38; p= 0.04) and anti-myeloperoxidase auto-antibodies (Bs vs III Vc: 0.76 vs 1.50; p= 0.02) and reduced level of inflammatory markers (CRP, ESR, and LDH). A quality of life analysis did not reveal significant treatment-related changes in arm A, while a detrimental effect was observed in arm B. It was recorded 1 partial response (arm A);11 disease stabilitazions (8/12 patients arm A, and 3/9 arm B) and 8 disease progressions (3/12 patients arm A and 5/9 arm B). MTD was not reached, while OBD was defined as a TSPP dosage of 300 µg. Conclusion Our results suggest that the TSPP vaccine is safe and immunologically active. On these bases we believe that TSPP deserves to be evaluated in further phase II trials in cancer patients. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr LB-229. doi:1538-7445.AM2012-LB-229</jats:p

Phase I trial of thymidylate synthase poly-epitope peptide (TSPP) vaccine in advanced cancer patients

Thymidylate synthase (TS) poly-epitope peptide (TSPP) is a 27-mer peptide vaccine containing the amino acidic sequences of three epitopes with HLA-A2.1-binding motifs of TS, an enzyme overexpressed in cancer cells, which plays a crucial role in DNA repair and replication. Based on the results of preclinical studies, we designed a phase Ib trial (TSPP/VAC1) to investigate, in a dose escalation setting, the safety and the biological activity of TSPP vaccination alone (arm A) or in combination with GM-CSF and IL-2 (arm B) in cancer patients. Twenty-one pretreated metastatic cancer patients, with a good performance status (ECOG ≤ 1) and no severe organ failure or immunological disease, were enrolled in the study (12 in arm A, nine in arm B) between April 2011 and January 2012, with a median follow-up of 28 months. TSPP resulted safe, and its maximal tolerated dose was not achieved. No grade 4 toxicity was observed. The most common adverse events were grade 2 dermatological reactions to the vaccine injection, cough, rhinitis, fever, poly-arthralgia, gastro-enteric symptoms and, to a lesser extent, moderate hypertension and hypothyroidism. We detected a significant rise in auto-antibodies and TS-epitope-specific CTL precursors. Furthermore, TSPP showed antitumor activity in this group of pretreated patients; indeed, we recorded one partial response and seven disease stabilizations (SD) in arm A, and three SD in arm B. Taken together, our findings provide the framework for the evaluation of the TSPP anti-tumor activity in further disease-oriented clinical trials