Biomedical subjects

Corinne Scaletta

Publications and source records attributed to Corinne Scaletta.

4 recordsLinked to original sources

PubMed2004

Fetal bone cells for tissue engineering.

We envision the use of human fetal bone cells for engineered regeneration of adult skeletal tissue. A description of their cellular function is then necessary. To our knowledge, there is no description of human primary fetal bone cells treated with differentiation factors. The characterization of fetal bone cells is particularly important as the pattern of secreted proteins from osteoblasts has been shown to change during aging. In the first part of this work, human primary fetal bone cells were compared to adult bone cells and mesenchymal stem cells for their ability to proliferate and to differentiate into osteoblasts in vitro. Cell proliferation, gene expression of bone markers, alkaline phosphatase (ALP) activity, and mineralization were analyzed during a time-course study. In the second part of this paper, bone fetal cells behavior exposed to osteogenic factors is further detailed. The doubling time of fetal bone cells was comparable to mesenchymal stem cells but significantly shorter than for adult bone cells. Gene expression of cbfa-1, ALP, alpha1 chain of type I collagen, and osteocalcin were upregulated in fetal bone cells after 12 days of treatment, with higher inductions than for adult and mesenchymal stem cells. The increase of ALP enzymatic activity was stronger for fetal than for adult bone cells reaching a maximum at day 10, but lower than for mesenchymal stem cells. Importantly, the mineralization process of bone fetal cells started earlier than adult bone and mesenchymal stem cells. Proliferation of fetal and adult bone cells was increased by dexamethasone, whereas 1alpha,25-dihydroxyvitamin D3 did not show any proliferative effect. Mineralization studies clearly demonstrated the presence of calcium deposits in the extracellular matrix of fetal bone cells. Nodule formation and calcification were strongly increased by the differentiation treatment, especially by dexamethasone. This study shows for the first time that human primary fetal bone cells could be of great interest for bone research, due to their fast growth rate and their ability to differentiate into mature osteoblasts. They represent an interesting and promising potential for therapeutic use in bone tissue engineering.

Adult↗

PubMed2002

Photoprotective potential of lycopene, beta-carotene, vitamin E, vitamin C and carnosic acid in UVA-irradiated human skin fibroblasts.

The photoprotective potential of the dietary antioxidants vitamin C, vitamin E, lycopene, beta-carotene, and the rosemary polyphenol, carnosic acid, was tested in human dermal fibroblasts exposed to ultraviolet-A (UVA) light. The carotenoids were prepared in special nanoparticle formulations together with vitamin C and/or vitamin E. Nanoparticle formulations, in contrast to dimethylsulphoxide, stablized lycopene in the cell culture medium and allowed efficient cellular uptake. The presence of vitamin E in the formulation further increased the stability and cellular uptake of lycopene. UVA irradiation of the human skin fibroblasts led to a 10-15-fold rise in metalloproteinase 1 (MMP-1) mRNA. This rise was suppressed in the presence of low microM concentrations of vitamin E, vitamin C, or carnosic acid but not with beta-carotene or lycopene. Indeed, in the presence of 0.5-1.0 microM beta-carotene or lycopene, the UVA-induced MMP-1 mRNA was further increased by 1.5-2-fold. This increase was totally suppressed when vitamin E was included in the nanoparticle formulation. Heme-oxygenase 1 (HO-1) mRNA expression was strongly induced by UVA irradiation but none of the antioxidants inhibited this effect at the concentrations used in this study. Indeed, beta-carotene or lycopene (0.5-1.0 microM) led to a further 1.5-fold rise in the UVA-induced HO-1 mRNA levels. In conclusion, vitamin C, vitamin E, and carnosic acid showed photoprotective potential. Lycopene and beta-carotene did not protect on their own but in the presence of vitamin E, their stability in culture was improved and the rise in MMP-1 mRNA expression was suppressed, suggesting a requirement for antioxidant protection of the carotenoids against formation of oxidative derivatives that can influence the cellular and molecular responses.

Abietanes↗

PubMed2002

Use of sunscreens in families living in Switzerland.

BACKGROUND: The hazards due to sun exposure are well known. Many recent studies have emphasized the protection against the harmful effects of the sun by the use of sunscreens and, moreover, by staying in the shade and wearing long-sleeved shirts, hats and sunglasses. Switzerland has one of the highest rates of skin cancer induction in Europe and the incidence of melanoma in Switzerland is constantly increasing with an incidence of 10-12/100,000 inhabitants/year. Interestingly, some studies have evoked the possibility that sunscreen use can increase the risk of melanoma by increasing overall sun exposure. OBJECTIVE AND METHODS: In this context, the aim of our study was to estimate the amount of sun exposure of children, and their parents, living in Switzerland and to give a description of how they protect themselves against sun irradiation. Questionnaires were provided to pediatricians in every state (canton) in Switzerland and were given to families coming for consultation. RESULTS: A total of 328 forms including 1,285 individuals were returned from most of the cantons in Switzerland. The majority of the Swiss families had 2 children under 16 years of age with middle-aged parents (30-45 years) and a central European skin type (light skin of type II-III, brown or blue eyes, and brown to blond hair). An important sun exposure was noted even though the population seems to be conscious of the associated dangers. Sunscreens were the first-line defense against sun exposure with clothing and shielding oneself from the sun not being highly used. Moreover, sunscreens tended to be misused with most people applying them at the beach or swimming pool (instead of 15 min before exposure) and few applications throughout the day. CONCLUSIONS: Prevention should imperatively be emphasized for lower overall sun exposure as sunscreens are primarily used at the beach and not in routine daily exposure. In addition, it is agreed that prevention campaigns would be better directed towards children because up to 80% of detrimental sun exposure occurs during childhood.

Adolescent↗

PubMedDate not supplied

Tissue engineered fetal skin constructs for paediatric burns.

Autologous skin-grafting is the gold standard for treatment of deep second and third degree burns. Available bioengineered skin products also necessitate this two-step surgical procedure. Therefore, we developed fetal skin constructs to improve healing of such degree burns. A bank of fetal skin cells was developed from one organ donation (4 cm2 of skin allowing the preparation of several million three-dimensional skin constructs, 9x12 cm, on native horse collagen). Successive fetal constructs were applied to eight patients at every change of dressing during 1-3 weeks in an outpatient setting. Complete closure was rapid (mean 15.3 days [SD 5.5]) with little hypertrophy of new skin and no retraction seen. This simple technique provided complete treatment without auto-grafting, showing that fetal skin cells might have great potential to treat burns and eventually acute and chronic wounds of other types.

Burns↗