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Triangular gold nano-plates have been synthesized by thermal decomposition of Au(I) dodecyl-mercaptide (i.e., AuSC12H25) dissolved in poly(vinyl acetate). Such special shape was achieved because of the ability of polymer side-groups (i.e., the acetate groups) to be selectively absorbed on the most acid faces of the growing gold nanocrystals, thus inhibiting crystal development along these crystallographic directions. Nano-plates had an average adge length of ca. 30nm and a thickness of a few nanometers.

In most skeletal tissue applications, an ideal scaffolds should be biocompatible and biodegradable in medium-long term; it should initially maintain its structural behaviours, allow cellular ingrowth and diffusion of nutrient, and used as carrier of growth factors and drugs. Actually many synthetic, natural and semi-synthetic organic and inorganic materials have been used, and even if they posses appropriate biological and biodegradable properties, their structural performances are not completely adequate. In order to satisfy all the complex requirement, composites polymer based materials technology can be implemented to designed an appropriate scaffolds. This technology will permits to design bio-inspired structure following the learning from nature approach that is applied to design scaffolds for bone, meniscus and intervertebral disc (nucleus) regeneration. For bone tissue reconstruction, in order to modulate mechanical properties and cell interaction, composite scaffolds made of poly(å-caprolactone) and hydroxyapatite were obtained by phase inversion and salt leaching technique. Both techniques permits to obtain scaffold with controlled micro and macro porosity. Poly(å-caprolactone) based polymers reinforced with degradable fibres were processed by composite technology, phase inversion and salt leaching technique to obtain scaffolds for meniscus regeneration. Injectable gel-like scaffolds were prepared by using esters of hyaluronic acid are used to engineer an nucleus pulposus substitute able to reproduce the viscoelastic properties of NP as well as to guide and promote bone marrow stem cells to adhere and differentiate according to a tissue engineering approach. The composite technology permits to design scaffolds with multifunctional behaviours: biodegradability, mechanical behaviour, cell viability, transport activity, to enhance the neo-tissue formation, determining the functionality and efficacy of the tissue engineered construct.

We present the foundations of the theory of functions of bounded variation and sets of finite perimeter in abstract Wiener spaces.

The evaluation of the biocompatibility of a material before clinical use is a long trial that requires a well planned sequence of steps. These procedures are now standardized at an international level. In particular, in the European Community, the rules of EN ISO 10993 are the guideline for each investigation in this field. The in vivo tests of biocompatibility are complementary to those performed in vitro and require compliance to the ethical and legal rules on animal experimentation. Biocompatibility tests must be performed on the final product or material, taking into account the nature, duration and conditions of the exposure in the human body, the physical and chemical features of the product, the toxicological activity of the chemical elements or compounds, and the presence of leachable materials. The tests should be applied with interpretation and judgement by the appropriate professionals qualified by training and experience taking into consideration factors relevant to the device/material, its intended use, and the current knowledge of the device/material provided by scientific reports and previous clinical experience.

In the last ten years many problems have been investigated which were denoted by Ennio De Giorgi in [Gio9lb] as free discontinuity problems.In such variational problems we want to minimize a functional which depends on a closed setKand on a function u suitably smooth outside ofK.A functional widely studied in this field was proposed by Mumford and Shah [MS89b] (see also [BZ87]) for a variational approach to the segmentation problem in computer vision theory. Other functionals have been considered in connection with fracture mechanics, liquid crystals theory, immiscible fluids, elastic-plastic plates (see [AFF93], [Amb90], [ACM97], [Car95], [CLT92], [CLT94], [CLT96], [CT91] and the references therein).