Osteogenic differentiation of adipose tissue-derived mesenchymal stem cells on nanostructured Ti6Al4V and Ti13Nb13Zr.

Bone tissue engineering and nanotechnology enable the design of suitable substitutes to restore and maintain the function of human bone tissues in complex fractures and other large skeletal defects. Long-term stability and functionality of prostheses depend on integration between bone cells and biocompatible implants. Human adipose tissue-derived mesenchymal stem cells (hAMSCs) have been shown to possess the same ability to differentiate into osteoblasts and to produce bone matrix of classical bone marrow derived stem cells (BMMSCs). Ti6A14V and Ti13Nb13Zr are two different biocompatible titanium alloys suitable for medical bone transplantation. Preliminary results from our Research Group demonstrated that smooth Ti6Al4V surfaces exhibit an osteoconductive action on hAMSCs, granting their differentiation into functional osteoblasts and sustaining bone matrix synthesis and calcification. The purpose of this study is to assay the ability of nanostructured Ti6Al4V and Ti13Nb13Zr alloys to preserve the growth and adhesion of hAMSCs and, mostly, to sustain and maintain their osteogenic differentiation and osteoblast activity. The overall results showed that both nanostructured titanium alloys are capable of sustaining cell adhesion and proliferation, to promote their differentiation into osteoblast lineage, and to support the activity of mature osteoblasts in terms of calcium deposition and bone extracellular matrix protein production.

In vitro effects of oestrogens, antioestrogens and SERMs on pancreatic solid pseudopapillary neoplasm-derived primary cell culture.

BACKGROUND: Solid-pseudopapillary neoplasms of the pancreas (SPNs) are uncommon tumours usually frequent in young women. Although the pathogenesis of SPNs is uncertain a potential influence of the sex hormone milieu on the biology of these tumours has been suggested. The controversial expression of oestrogen receptors (ERs) in SPNs, provide a rationale for studying the effects of oestrogenic molecules on SPN development. METHODS: The expression of a large series of hormonal ligands and receptors was evaluated in tissue specimens and in a primary cell culture (SPNC), obtained from a SPN in young female patient. The effects of 17beta-oestradiol (17betaE2), ICI 182,780 and tamoxifen (Tam) on cell replication and growth were examined. RESULTS: We have established SPNC primary line. Immunocytochemical analysis was positive for vimentin, cyclin D1 and beta-catenin and negative for cytokeratin, CD10 and neuroendocrine markers, in line with the immunostaining features of the tumoral tissue. Expression of ERalpha, ERbeta and progesterone mRNAs was demonstrated in SPNC and tumor tissue. A proliferative and antiproliferative action of 17betaE2 and Tam respectively were proved in SPNC. CONCLUSION: In conclusion, we provide the first direct evidence that oestrogenic molecules can influence proliferation of SPNC, offering future strategies in the control of this neoplasia via selective ER modulators.

In vitro differentiation of human mesenchymal stem cells on Ti6Al4V surfaces.

Long-term stability of arthroplasty prosthesis depends on the integration between the bone tissue and the implanted biomaterials, which requires the contribution of osteoblastic precursors and their continuous differentiation into the osteoblastic phenotype. Classically, these interactions are tested in vitro using mesenchymal stem cells (MSCs) isolated and ex vivo expanded from bone marrow aspirates. Human adipose tissue-derived stromal cells (AMSCs) may be a more convenient source of MSCs, according to their abundance and accessibility, but no data are available on their in vitro interactions with hard biomaterials. The aim of this work is to compare the osteogenic potential of human AMSCs and bone marrow-derived MSCs (BMMSCs) and to evaluate their response to Ti6Al4V alloy in terms of adhesion, proliferation and differentiation features, using the human osteosarcoma cell line SaOS-2 for comparison. The overall results showed that AMSCs have the same ability to produce bone matrix as BMMSCs and that Ti6Al4V surfaces exhibit an osteoinductive action on AMSCs, promoting their differentiation into functional osteoblasts and increasing bone formation. In conclusion, adipose tissue is a promising autologous source of osteoblastic cells with important clinical implications for bone tissue engineering.