Tissue engineered scaffolds must have an organized and repeatable microstructure which enables cells to assemble in an ordered matrix that allows adequate nutriental perfusion. In this work, to evaluate the reciprocal cell interactions of endothelial and osteoblast-like cells, human osteoblast-like cells (MG63) and Human Umbilical Vein Endothelial Cells (HUVEC) were co-seeded onto 3D geometrically controlled porous poly(ε-caprolactone) (PCL) and cultured by means of a rotary cell culture system (RCCS-4DQ). In our dynamic co-culture system, the lack of significant enhancement of osteoblast ALP activity and ECM production indicated that the microgravity conditions of the rotary system affected the cells by favoring their proliferation and cellular cross-talk. These results emphasize how osteoblasts increase endothelial cell proliferate and endothelial cells amplify the growth of osteoblasts but decrease their differentiation. This dynamic seeding of osteoblasts and endothelial cells onto a 3D polymeric scaffold may represent a unique approach for studying the mechanisms of interaction of endothelial and osteoblast cells as well as achieve a functional hybrid in which angiogenesis, furnished by neo-vascular organization of endothelial cells may further support osteoblasts growth. Furthermore, this in vitro model may be useful in examining the applicability of novel material structures for tissue engineering.

The microenvironment in psoriasis differs from those of atopic dermatitis and healthy skin; it could induce resident MSCs to produce angiogenic and proinflammatory mediators which lead to a reduction in the antioxidant capacity of these cells, contributing to the development of skin lesions in psoriasis.

Objective To assess human unstimulated whole saliva components during pregnancy, to determine the relation, if any, between pregnancy and oral health, particularly total protein concentration, a-amylase activity, sialic acid content and calcium and phosphate concentrations were evaluated.Design Cross-sectional study. Participants Forty-five healthy primigravid women; 1 5 nonpregnant women acted as controls. Results 1. A higher total protein content at 10 and 21 weeks of gestation with respect to the controls and to pregnant women at 40 weeks; 2. a higher a-amylase activity at 10 and 21 weeks of gestation compared with the controls and to pregnant women at 40 weeks; 3. an increased sialic acid content at 21 and 40 weeks; 4. decreased calcium and phosphorus concentrations at 21 and 40 weeks of gestation.Conclusions Pregnancy modifies saliva composition. This could play a pivotal role in the incidence of pregnancy-induced dental caries. INTRODUCTIONFemale steroid sex hormones influence oral health through different mechanisms. Gingival tissue is affected by hormonal changes during puberty and pregnancy, as shown by more pronounced subclinical signs of gingivial inflammation during the ovulatory phase of the menstrual cycle and by the worsening of pre-existing gingivitis during human pregnancy. Pregnancy induces an increased response of the gingival tissues to local factors, such as plaque and tartar, through disturbance of tissue metabolism4.Besides the direct effect on tissue metabolism, pregnancy and the menstrual cycle alter the composition of human saliva, as a response to the changed steroid hormone levels. Many human studies have indicated that hormones influence the composition of female saliva, particularly at the time of ovulation. Correlation has been found between the ovulatory status of women and the phosphate level5. A cyclic variation has been also observed in sialic acid, glucose and some salivary electrolytesG8. Saliva plays a critical role in the maintenance of oral health, as it contains many innate and acquired factors with a protective role on oral tissue^^.^^. rate have been reported, and changes in salivary electrolyte levels and IgA concentration have been A decrease in salivary HC03 during pregnancy has been related to the effect of progesterone in lowering plasma bicarbonate con~entration'~.'~. D'Alessandro et al. l6 have suggested a relation between the protein changes in parotid saliva and the hormonal modifications during pregnancy. Secretory proteins are produced by many salivary cell types and salivary total protein content could reflect general exocrine capacity". Many salivary proteins have enzymatic functions, such as a-amylase, which represents the major component of the parotid secretion and is also present in the submandibular fluid, representing about 50% of total proteins.Laine et al. I4 did not find significant changes in salivary amylase, lysozyme or peroxidase activities during pregnancy. Furthermore, the whole saliva levels of thiocyanate, hypothiocyanite, lactoferrin, to...

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The interaction between low density lipoproteins (LDL) and platelets might play a central role in the development of atherosclerosis in diabetes. The aim of the present study was to investigate whether the glycation of LDL is associated with modifications of their physico-chemical and functional properties and to study the action of glycated LDL (glycLDL) on platelets. LDL and platelets were isolated from 15 healthy subjects. The content of thiobarbituric acid-reactive substances and the generalized polarization of the fluorescent probe Laurdan were determined in LDL glycated in vitro. Platelets were incubated with native LDL, GlycLDL, and minimally oxidized LDL, and the following parameters were evaluated: platelet aggregation, nitric oxide production, intracellular Ca(2+) concentrations, Na(+)/K(+)-adenosine triphosphatase (Na(+)/K(+)-ATPase), and Ca(2+)-ATPase activities. GlycLDL showed increased thiobarbituric acid-reactive substance levels, a red shift of the Laurdan emission maximum, and a decrease in generalized polarization, indicating a higher polarity and a reduced molecular order compared with native LDL. GlycLDL caused a significant increase in platelet nitric oxide production, intracellular Ca(2+) concentration, and aggregating response to ADP; an inhibition of the platelet membrane Na(+)/K(+)-ATPase activity; and a stimulation of Ca(2+)-ATPase activity. Minimally oxidized LDL did not cause statistically significant changes in the parameters studied. The present work demonstrates that glycation induces compositional and structural changes in LDL and suggests that an altered interaction between glycLDL and platelets might play a role in the vascular complications of diabetes.

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The skin is constantly exposed to exogenous and endogenous sources of reactive oxygen species (ROS). An adequate balance between ROS levels and antioxidant defenses is necessary for the optimal cell and tissue functions, especially for the skin, since it must face additional ROS sources that do not affect other tissues, including UV radiation. Melanocytes are more exposed to oxidative stress than other cells, also due to the melanin production process, which itself contributes to generating ROS. There is an increasing amount of evidence that oxidative stress may play a role in many skin diseases, including melanoma, being the primary cause or being a cofactor that aggravates the primary condition. Indeed, oxidative stress is emerging as another major force involved in all the phases of melanoma development, not only in the arising of the malignancy but also in the progression toward the metastatic phenotype. Furthermore, oxidative stress seems to play a role also in chemoresistance and thus has become a target for therapy. In this review, we discuss the existing knowledge on oxidative stress in the skin, examining sources and defenses, giving particular consideration to melanocytes. Therefore, we focus on the significance of oxidative stress in melanoma, thus analyzing the possibility to exploit the induction of oxidative stress as a therapeutic strategy to improve the effectiveness of therapeutic management of melanoma.