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We introduce a Faraday magnetometer based on an analytical balance in which we were able to apply magnetic fields up to 0.14 T. We calibrated it with a 1 mm Ni sphere previously characterized in a superconducting quantum interference device (SQUID) magnetometer. The proposed magnetometer reached a theoretical sensitivity of 3 × 10−8A m2. We demonstrated its operation on magnetic composite scaffolds made of poly(ε-caprolactone)/iron-doped hydroxyapatite. To confirm the validity of the method, we measured the same scaffold properties in a SQUID magnetometer. The agreement between the two measurements was within 5% at 0.127 T and 12% at 24 mT. With the addition, for a small cost, of a permanent magnet and computer controlled linear translators, we were thus able to assemble a Faraday magnetometer based on an analytical balance, which is a virtually ubiquitous instrument. This will make simple but effective magnetometry easily accessible to most laboratories, in particular, to life sciences ones, which are increasingly interested in magnetic materials.

Over the past few years, the influence of static or dynamic magnetic fields on biological systems has become a topic of considerable interest. Magnetism has recently been implicated to play significant roles in the regulation of cell responses and, for this reason, it is revolutionizing many aspects of healthcare, also suggesting new opportunities in tissue engineering. The aim of the present study was to analyze the effect of the application mode of a time-dependent magnetic field on the behavior of human mesenchymal stem cells (hMSCs) seeded on 3D additive-manufactured poly(ɛ-caprolactone)/iron-doped hydroxyapatite (PCL/FeHA) nanocomposite scaffolds., Graphical abstract Image 1, Highlights • Additive Manufacturing for bone tissue engineering. • Analysis of the effect of the application mode of a time-dependent magnetic field on the cell-behavior. • 3D nanocomposite magnetic scaffolds.

The bioactivity of sol–gel synthesized poly(e-caprolactone) (PCL)/TiO2 or poly(e-caprolactone)/ZrO2 particles was already known. In designing innovative 2D composite substrates for hard-tissue engineering, the possibility to embed PCL/TiO2 or PCL/ZrO2 hybrid fillers into a PCL matrix was previously proposed. In the present study, the potential of 3D fiber-deposition technique to design morphologically controlled scaffolds consisting of PCL reinforced with PCL/TiO2 or PCL/ZrO2 hybrid fillers was demonstrated. Finite element analysis was initially carried out on 2D substrates to find a correlation between the previously obtained results from the small punch test and the Young's modulus of the materials, whilst mechanical and biological tests were suitably performed on rapid prototyped scaffolds to assess the effects of the inclusion of the hybrid fillers on the performances of the 3D porous structures. The role of the inclusion of the hybrid fillers in improving the compressive modulus (about 90 MPa) and the cell viability/proliferation was demonstrated. POLYM. COMPOS., 34:1413–1417, 2013. © 2013 Society of Plastics Engineers

The ability to engineer scaffolds that resemble the transition between tissues would be beneficial to improve repair of complex organs, but has yet to be achieved. In order to mimic tissue organization, such constructs should present continuous gradients of geometry, stiffness and biochemical composition. Although the introduction of rapid prototyping or additive manufacturing techniques allows deposition of heterogeneous layers and shape control, the creation of surface chemical gradients has not been explored on three-dimensional (3D) scaffolds obtained through fused deposition modelling technique. Thus, the goal of this study was to introduce a gradient functionalization method in which a poly(e-caprolactone) surface was first aminolysed and subsequently covered with collagen via carbodiimide reaction. The 2D constructs were characterized for their amine and collagen contents, wettability, surface topography and biofunctionality. Finally, chemical gradients were created in 3D printed scaffolds with controlled geometry and porosity. The combination of additive manufacturing and surface modification is a viable tool for the fabrication of 3D constructs with controlled structural and chemical gradients. These constructs can be employed for mimicking continuous tissue gradients for interface tissue engineering.

Diversos estudos verificaram os efeitos agudos de diferentes atividades condicionantes no desempenho em testes de velocidade. O objetivo deste estudo foi verificar o efeito agudo da Contração Isométrica Voluntária Máxima (CVIM) com adição de vibração mecânica no desempenho em corrida de velocidade. Participaram do estudo 8 jovens atletas velocistas do sexo masculino, idade 20,23 ± 2,46 anos, massa corporal 69,9 ± 4,2 kg, estatura 1,77 ± 0,05 m e melhor resultado nos 100 m 11.14 ± 0,32 s. Os atletas foram submetidos a três condições experimentais: Contração voluntária isométrica máxima (CVIM), CVIM com adição de vibração mecânica (CVIM+VIB) e Controle (CON), em dias não consecutivos, de maneira aleatória. Na Condição CVIM, os atletas realizaram uma contração Isométrica máxima de membros inferiores de 5s como atividade condicionante, enquanto na condição CVIM+VIB realizaram a mesma contração com a adição de vibração mecânica (26 Hz, 6mm). Em todas as condições, a variável dependente para comparação das diferentes atividades condicionantes foi o tempo no teste de 40m, incluindo os tempos parciais aos 10, 20, 30 e final aos 40m, mensurados imediatamente após a contração (0 min) e após 8 minutos de descanso ativo (8 min). A análise dos resultados não demonstrou diferenças significativas nos tempos parciais aos 10 e 20 m entre as condições. No tempo parcial aos 30m, houve diferença significativa entre as condições CVIM 0 min e CVIM+VIB 8 min (3.94 ± 0.12 s Vs. 3.85 ± 0.13 s). No tempo final aos 40m, diferenças significativas foram encontradas entre as condições CVIM 0 min e CVIM 8 min (5.01 ± 0.17 s Vs. 4.91 ± 0,15 s) e entre as condições CVIM 0 min e CVIM+VIB 8 min (5.01 ± 0.17 s Vs. 4.89 ± 0,16 s). A CVIM com e sem a adição de vibração mecânica parece não melhorar o tempo no teste de 40m após 0 e 8 min de descanso. Several studies have verified the acute effects of different preconditioning activities on sprint performance. The aim of this study was to investigate the acute effect of Maximum Voluntary Contraction (MVC) with the addition of mechanical vibrations on sprint test performance. The sample consisted of 8 young male sprinters, age 20.23 ± 2.46 years, body weight 69.9 ± 4.2 kg, height 1.77 ± 0.05 and personal best on 100 m 11.14 ± 0, 32 s. Each athlete participated in three separate trials: Maximum Voluntary Contraction (MVC), MVC with the addition of mechanical vibration (MVC + VIB) and control (CON), on non-consecutive days, using randomized treatment sessions (1 treatment per session). In MVC condition, athletes performed a 5s maximal isometric contraction of the lower limbs as preconditioning activity, while on the condition VIB + MIVC performed the same contraction with the addition of mechanical vibration (26 Hz, 6 mm). In all conditions, the dependent variable for comparison the different pre-conditioning activities was the time at 40m sprint test, including the split times at 10, 20, 30 and 40m, recorded immediately after the contraction (0 min) and after 8 minutes of active rest (8 min). Results indicated no significant differences in split times at 10 and 20 m between the conditions. In the 30m split time, a significant difference was found between the MVC 0 min and MVC +VIB 8 min conditions (3.94 ± 0.12 s vs. 3.85 ± 0.13 s). In the 40m split time between MVC 0 min and MVC 8 min conditions (5:01 ± 0:17 vs. 4.91 ± 0.15 s) and between MVC 0 min an MVC+VIB 8 min conditions (5:01 ± 0:17 ± 4.89 s Vs. 0.16 s). The MVC with and without the addition of mechanical vibration seems not to improve 40m sprint test after 0 and 8 min of rest.

A vinyl-terminated polycaprolactone has been developed for tissue engineering applications using a one-step synthesis and functionalization method based on ring opening polymerization (ROP) of ε-Caprolactone, with hydroxyl ethyl vinyl ether (HEVE) acting both as the initiator of ROP and as photo-curable functional group. The proposed method employs a catalyst based on aluminium, instead of the most popular Tin(II) 2-ethylhexanoate, to reduce the cytotoxicity. Following the synthesis of the vinyl-terminated polycaprolactone, its reaction with fumaryl chloride (FuCl) results in a divinyl-fumarate polycaprolactone (VPCLF). The polymers obtained were thoroughly characterized using Fourier transform infrared spectroscopy (FTIR) and gel permeation chromatography (GPC) techniques. The polymer has been successfully employed, in combination with N-vinyl pyrrolidone (NVP), to fabricate films and computer-designed porous scaffolds by micro-stereolithography (μ-SL) with gyroid and diamond architectures. Characterization of the networks indicated the influence of NVP content on the network properties. Human mesenchymal stem cells adhered and spread onto VPCLF/NVP networks showing good biological properties and no cytotoxic effect. Copyright © 2016 John WileySons, Ltd.

Polymer-based composites are ideal for applications where high strength-to-weight and stiffness-to-weight ratios are required. In the biomedical field, fiber-reinforced polymers have replaced metals, emerging as suitable alternative. Reverse engineering and additive manufacturing methods are required to achieve the design of customized devices with specific shape and size. At the same time, micro-mechanics and macro-mechanics play an important role in the development of highly functional composite materials. The aim of this research is to develop customized 3D models of a human mandible using reverse engineering, additive manufacturing and composite material technology. Experiments were carried out by loading the models through the condyles and the results show the potential to reproduce the mechanical behavior of a human mandible. Taking into account the curves of the load-arch width decrease, the stiffness of the 3D composite model was 14.1± 1.9 N/mm, which is close to the tested human mandible (17.5 ± 1.8 N/mm).

In order to mimic the behaviors of natural tissue, the optimal approach for designing novel biomaterials has to be inspired to nature guidelines. One of the major challenge consists in the development of well-organized structures or scaffolds with controlled porosity in terms of pore size, pore shape and interconnection degree able to guide new tissue formation during the in vivo degradation following the scaffold implantation. Scaffolds endowed with molecular cues together to a controlled degradation profile should contribute to cell proliferation and differentiation, controlled vascularization, promoting the remodeling of neo tissue through a gradual transmission of bio-chemicals and biophysical signals as performed by the extracellular matrix (ECM). Here, different polymers and composites have been investigated to design scaffolds with peculiar micro and/or nanometric morphological features in order to satisfy all these requirements: a) bioactive scaffolds, with tailored porosity and high pores interconnectivity were developed by integrating PLA fibres, Calcium Phosphates particles or Hyaff11 phases into a Poly(ε-caprolactone) (PCL) matrix by the combination of filament winding technology and phase inversion/salt leaching technique as mineralised ECM analogue for bone regeneration; b) custom made PCL/hydroxyapatite scaffolds were designed by imaging and rapid prototyping technologies for the osteochondral defect. c) Ester of Hyaluronic Acid reinforced with degradable fibres were processed by composite technology, phase inversion and salt leaching technique, to obtain scaffolds for meniscus regeneration. d) PCL and gelatin nanofibres were obtained by highly customized fibre deposition via electrospinning to guide the nerve outgrowth in nerve regeneration. All the proposed approaches offer the chance of realizing tailor-made platforms with micro/nanoscale architecture and chemical composition suitable for the regeneration of the extracellular matrix of a large variety of natural tissues (i.e, bone, menisci, osteochondral and peripheral nervous tissues).

A computer-aided design (CAD)-based approach and sol-gel chemistry were used to design a multilayer dental post with a compositional gradient and a Young’s modulus varying from 12.4 to 2.3 GPa in the coronal-apical direction. Specifically, we propose a theoretical multilayer post design, consisting of titanium dioxide (TiO2) and TiO2/poly(ε-caprolactone) (PCL) hybrid materials containing PCL up to 24% by weight obtained using the sol-gel method. The current study aimed to analyze the effect of the designed multilayer dental post in endodontically treated anterior teeth. Stress distribution was investigated along and between the post and the surrounding structures. In comparison to a metal post, the most uniform distributions with lower stress values and no significant stress concentration were found when using the multilayer post.

Spinal disease due to intervertebral disc degeneration represents a serious medical problem which affects many people worldwide. Disc arthroplasty may be considered the future ‘‘gold standard’’ of back pain treatment, even if problems related to available disc prostheses are considered. Hence, the aim of the present study was to improve the artificial disc technology by proposing the engineering of a pilot-scale device production process for a total multi-component intervertebral disc prosthesis. The device is made up of a poly(2-hydroxyethyl methacrylate)/poly(methyl methacrylate) (PHEMA/PMMA) (80/20 w/w) semi-interpenetrating polymer network (s-IPN) composite hydrogel reinforced with poly(ethylene terephthalate) (PET) fibers as annulus/nucleus substitute, and two hydroxyapatite-reinforced polyethylene composite (HAPEX TM) endplates in order to anchor the multi-component device to the vertebral bodies. Static and dynamic—mechanical characterization show appropriate mechanical behavior. An example of engineering of a suitable pilot-scale device production process is also proposed in order to manufacture custom made implants.

Titanium dioxide (TiO2) and TiO2 glasses containing poly(e-caprolactone) (PCL) up to 24% by weight were obtained by the sol–gel process. Powder compaction was achieved providing heat and pressure. Properties were evaluated through compression and bending tests assisted by X-ray micro-computed tomography imaging. The effects of compaction conditions (i.e. temperature, pressure and duration) on mechanical properties of inorganic/organic composites were investigated. Biocompatibility tests on organic/inorganic composites were carried out using human cells and the MTT assay to determine viability. Results indicated that the mechanical properties (i.e. Young’s modulus and maximum strength), in both compression and bending, were a function of the compression moulding conditions. Highest mechanical properties were measured using a compaction pressure of 1500MPa acting for 90 min at a die temperature of 100 1C. The results, however, also suggest that mechanical properties can be tailored by varying the amount of PCL to TiO2. Strength and stiffness spanned between the properties of spongy and cortical bone. Young’s modulus in both compression and bending were higher for PCL amounts of 6%. Instead, higher bending strength values were measured for PCL amounts of 12%. These weight amounts of PCL also provide higher average density values, thus suggesting that the polymeric phase is effective in toughening TiO2-based materials. The investigated materials also showed a very good cytocompatibility as indicated by the MTT assay results. r 2007 Elsevier Ltd. All rights reserved.

In the past few years, researchers have focused on the design and development of three-dimensional (3D) advanced scaf- folds, which offer significant advantages in terms of cell performance. The introduction of magnetic features into scaffold technology could offer innovative opportunities to control cell populations within 3D microenvironments, with the potential to enhance their use in tissue regeneration or in cell-based analysis. In the present study, 3D fully biodegradable and magnetic nanocomposite scaffolds for bone tissue engineering, consisting of a poly( -caprolactone) (PCL) matrix rein- forced with iron-doped hydroxyapatite (FeHA) nanoparticles, were designed and manufactured using a rapid prototyping technique. The performances of these novel 3D PCL/FeHA scaffolds were assessed through a combination of theoretical evaluation, experimental in vitro analyses and in vivo testing in a rabbit animal model. The results from mechanical com- pression tests were consistent with FEM simulations. The in vitro results showed that the cell growth in the magnetized scaffolds was 2.2-fold greater than that in non-magnetized ones. In vivo experiments further suggested that, after only 4 weeks, the PCL/FeHA scaffolds were completely filled with newly formed bone, proving a good level of histocompatibil- ity. All of the results suggest that the introduction of magnetic features into biocompatible materials may confer significant advantages in terms of 3D cell assembly

The grafting of galactose units onto poly(epsilon-caprolactone) (PCL) substrates by a wet chemistry two-step procedure is proposed. Even though a reduction of hardness from 0.58-0.31 GPa to 0.12-0.05 GPa is achieved, the chemical functionalization does not negatively affect the tensile modulus (332.2 +/- 31.3 MPa and 328.5 +/- 34.7 MPa for unmodified and surface-modified PCL, respectively) and strength (15.1 +/- 1.3 MPa and 14.8 +/- 1.5 MPa as assessed before and after the surface modification, respectively), as well as the mechanical behaviour evaluated through small punch test. XPS and enzyme-linked lectin assay (ELLA) demonstrate the presence, and also the correct exposition of the saccharidic epitope on PCL substrates. The introduction of carbohydrate moieties on the PCL surfaces clearly enhances the hydrophilicity of the substrate, as the water contact angle decreases from 82.1 +/- 5.8 degrees to 62.1 +/- 4.2 degrees. Furthermore, preliminary biological analysis shows human mesenchymal stem cell viability over time and an improvement of cell adhesion and spreading. (C) 2014

Dentin bonding systems (DBS) have been developed in order to bond restorative materials (i.e. composite) to tooth tissues when function and integrity have to be re-established. Adhesion to dentin results from the penetration of DBS into the demineralised substrate constituted by a conditioned collagen network. The long-term stability of a restored tooth is mainly affected by the seal of the restorative material on the dental structures. Although leakage through the dentin-DBS interface has been widely reported, 3D investigation technique and accurate non-destructive measurements of leakage as functions of mechanical cycling have never been provided. To address these issues, the properties of the material interface are analysed using micro-tensile static and dynamic tests, assisted by the finite element modelling and by the X-ray computed micro-tomography. The dual energy absorption technique, with the synchrotron beam light, has been developed to investigate, in a non-destructive manner, the effect of mechanical cycling on leakage of a silver nitrate staining solution at the dentin-DBS interface. The effect of the pulpal roof on the stress distribution in the coronal dentin-DBS-composite interface has been investigated and the level at which the state of stress can be assumed to be uniform within acceptable limits has been defined. The tensile static and dynamic results suggest that the adhesive strength for the multi-step DBS resulted significantly higher than the other investigated DBS. Imaging results indicate that 3D leakage occurs radially at the dentin-adhesive interface through the interface itself rather than through the unconditioned dentin bulk; moreover, the dynamic tensile loading allows a more diffuse staining penetration.

Intervertebral disc (IVD) degeneration is one of the main causes of low back pain. Current surgical treatments are complex and generally do not fully restore spine mobility. Development of injectable extracellular matrix-based hydrogels offers an opportunity for minimally invasive treatment of IVD degeneration. Here we analyze a specific formulation of collagen-low molecular weight hyaluronic acid (LMW HA) semi-interpenetrating network (semi-IPN) loaded with gelatin microspheres as a potential material for tissue engineering of the inner part of the IVD, the nucleus pulposus (NP). The material displayed a gel-like behavior, it was easily injectable as demonstrated by suitable tests and did not induce cytotoxicity or inflammation. Importantly, it supported the growth and chondrogenic differentiation potential of mesenchymal stem cells (MSC) and nasal chondrocytes (NC) in vitro and in vivo. These properties of the hydrogel were successfully combined with TGF-?3 delivery by gelatin microspheres, which promoted the chondrogenic phenotype. Altogether, collagen-LMW HA loaded with gelatin microspheres represents a good candidate material for NP tissue engineering as it combines important rheological, functional and biological features.

Objectives: To evaluate temperature profiles developing in the root during warm compaction of gutta-percha with the heat sources System B and System MB Obtura (Analityc Technology, Redmond, WA, USA). Thirty extracted human incisor teeth were used. Root canals were cleaned and shaped by means of Protaper rotary files (Dentsply-Maillefer, Belgium), and imaging was performed by micro-CT (Skyscan 1072, Aartselaar, Belgium). Methods: Teeth were instrumented with K-type thermocouples, and the roots were filled with thermoplastic gutta-percha. Vertical compaction was achieved through the heat sources System B and System MB, and temperature profiles were detect-ed by means of NI Dac Interface controlled by the LabView System. With both heat sources, higher temperature levels were recorded in the region of the root far from the apex. When the warm plugger tip was positioned at a distance of 3 mm from the root apex, temperature levels of about 180°C were used to soften gutta-percha, and no statistically significant differences were observed between peak temperatures developed by the two heating sources at the root apex. However, a temperature level higher than 40°C was maintained for a longer time with System MB. Results: Statistically significant differences were observed in peak temperature levels recorded far from the root apex. Thus, with a temperature of about 180°C and the warm plugger positioned at 3 mm from the root apex, both heating sources led to a temperature slightly higher than 40°C at the apex of the root, suggesting that the gutta-percha was properly softened. Significance: A temperature level higher than 40°C was maintained for a longer time with System MB, thus providing an ad-equate time for warm compaction of the gutta-percha.

The grafting of galactose units onto poly(e-caprolactone) (PCL) substrates by a wet chemistry two-step procedure is proposed. Even though a reduction of hardness from 0.58-0.31 GPa to 0.12-0.05 GPa is achieved, the chemical functionalization does not negatively affect the tensile modulus (332.2 ± 31.3 MPa and 328.5 ± 34.7 MPa for unmodified and surface-modified PCL, respectively) and strength (15.1 ± 1.3 MPa and 14.8 ± 1.5 MPa as assessed before and after the surface modification, respec- tively), as well as the mechanical behaviour evaluated through small punch test. XPS and enzyme-linked lectin assay (ELLA) demonstrate the presence, and also the correct exposition of the saccharidic epitope on PCL substrates. The introduction of carbohydrate moieties on the PCL surfaces clearly enhances the hydrophilicity of the substrate, as the water contact angle decreases from 82.1 ± 5.8 to 62.1 ± 4.2. Furthermore, preliminary biological analysis shows human mesenchymal stem cell viability over time and an improvement of cell adhesion and spreading.

This study aimed at investigating the effects of titanium implants and different configurations of full- arch prostheses on the biomechanics of edentulous mandibles. Reverse engineered, composite, anisotropic, edentulous mandibles made of a poly(methylmethacrylate) core and a glass fibre reinforced outer shell were rapid prototyped and instrumented with strain gauges. Brånemark implants RP platforms in conjunction with titanium Procera one-piece or two-piece bridges were used to simulate oral rehabilitations. A lateral load through the gonion regions was used to test the biomechanical effects of the rehabilitations. In addition, strains due to misfit of the one-piece titanium bridge were compared to those produced by one-piece cast gold bridges. Milled titanium bridges had a better fit than cast gold bridges. The stress distribution in mandibular bone rehabilitated with a one-piece bridge was more perturbed than that observed with a two-piece bridge. In particular the former induced a stress concentration and stress shielding in the molar and symphysis regions, while for the latter design these stresses were strongly reduced. In conclusion, prosthetic frameworks changed the biomechanics of the mandible as a result of both their design and manufacturing technology.

Poly(-caprolactone), PCL, has been functionalized with a biologically relevant monosaccharide, i.e. glucosamine, in a single step process downstream to material fabrication. Glucosamine-functionalised PCL showed enhanced cell density and spreading then the non-functionalised samples

The restoration of tissue biomechanical function represents a great challenge, underlining the need to mimic tissue structure and mechanical behavior through suitable prosthesis and scaffold designs. For this reason, several materials, technologies, and designs have been widely proposed and studied from an experimental and/or a clinical point of view. Polymer-based composite materials are suitable candidates for applications where high strength-to-weight and stiffness-to-weight ratios and specific performances are required. Taking into account tissue structure-function relationships, the design of biomimetic composite devices able to reproduce the multiscale structural hierarchy of complex tissues represents a crucial feature for tissue repair and regeneration. In particular, this article aims at stressing the importance of polymer-based composite materials to design advanced prostheses and scaffolds for soft tissue engineering, with a special focus on tendons, ligaments, intervertebral disk, and meniscus. Keywords: soft tissues; polymer-based composite materials; prostheses; scaffolds; tendons; ligaments; intervertebral disk; meniscus

Orthodontic treatment is strongly dependent on the loads developed by metal wires, and the choice of an orthodontic archwire should be based on its mechanical performance. The desire of both orthodontists and engineers would be to predict the mechanical behavior of archwires. To this aim, Gum Metal (Toyota Central R&L Labs., Inc.), TMA (ORMCO), 35°C Copper NiTi (SDS ORMCO), Thermalloy Plus (Rocky Mountain), Nitinol SE (3M Unitek), and NiTi (SDS ORMCO) were tested according to dynamic mechanical analysis and differential scanning calorimetry. A model was also developed to predict the elastic modulus of superelastic wires. Results from experimental tests have highlighted that superelastic wires are very sensitive to temperature variations occurring in the oral environment, while the proposed model seems to be reliable to predict the Young’s modulus allowing to correlate calorimetric and mechanical data. Furthermore, Gum Metal wire behaves as an elastic material with a very low Young’s modulus, and it can be particularly useful for the initial stage of orthodontic treatments.

Polymer-based composite materials are ideal for applications where high stiffness-to-weight and strength-to-weight ratios are required. From aerospace and aeronautical field to biomedical applications, fiber-reinforced polymers have replaced metals, thus emerging as an interesting alternative. As widely reported, the mechanical behavior of the composite materials involves investigation on micro- and macro-scale, taking into consideration micromechanics, macromechanics and lamination theory. Clinical situations often require repairing connective tissues and the use of composite materials may be suitable for these applications because of the possibility to design tissue substitutes or implants with the required mechanical properties. Accordingly, this review aims at stressing the importance of fiber-reinforced composite materials to make advanced and biomimetic prostheses with tailored mechanical properties, starting from the basic principle design, technologies, and a brief overview of composites applications in several fields. Fiber-reinforced composite materials for artificial tendons, ligaments, and intervertebral discs, as well as for hip stems and mandible models will be reviewed, highlighting the possibility to mimic the mechanical properties of the soft and hard tissues that they replace. © 2011 Società Italiana Biomateriali.

Tissue engineering represents an interesting approach which aims to create tissues and organs de novo. In designing scaffolds for tissue engineering applications, the principal goal is to mimic the function of the natural extracellular matrix, providing a temporary template for the growth of target tissues. For this reason, scaffolds should possess suitable mechanical properties and architecture to play their specific role. In this paper, limitations of conventional scaffold fabrication methods will be briefly introduced, and rapid prototyping techniques will be described as advanced processing methods to realize customized scaffolds with controlled internal microarchitecture. Among the rapid prototyping techniques, the potential and challenges of 3D fiber deposition to create multifunctional and tailor-made scaffolds will be reviewed.

Tissue engineering may be defined as the application of biological, chemical and engineering principles toward the repair, restoration or regeneration of living tissue using biomaterials, cells and biologically active molecules alone or in combinations. The rapid restoration of tissue biomechanical function represents a great challenge, highlighting the need to mimic tissue structure and mechanical behavior through scaffold designs. For this reason, several biodegradable and bioresorbable materials, as well as technologies and scaffold designs, have been widely investigated from an experimental and/or clinical point of view. Accordingly, this review aims at stressing the importance of polymer-based composite materials to make multifunctional scaffolds for tissue engineering, with a special focus on bone, ligaments, meniscus and cartilage. Moreover, polymer-based nanocomposites will also be briefly introduced as an interesting strategy to improve the biological and mechanical performances of polymer scaffolds, especially for bone tissue engineering.

Purpose: The importance of polymer-based composite materials to make multifunctional substrates for tissue engineering and the strategies to improve their performances have been stressed in the literature. Bioactive features of sol-gel synthesized poly(epsilon-caprolactone)/TiO(2) or poly(epsilon-caprolactone)/ZrO(2) organic-inorganic hybrid materials are widely documented. Accordingly, the aim of this preliminary research was to develop advanced composite substrates consisting of a poly(epsilon-caprolactone) matrix reinforced with sol-gel synthesized PCL/TiO(2) or PCL/ZrO(2) hybrid fillers. Methods: Micro-computed tomography and atomic force microscopy analyses allowed to study surface topography and roughness. On the other hand, mechanical and biological performances were evaluated by small punch tests and Alamar Blue (TM) assay, respectively. Results: Micro-computed tomography and atomic force microscopy analyses highlighted the effect of the preparation technique. Results from small punch tests and Alamar Blue (TM) assay evidenced that PCL reinforced with Ti2 (PCL=12, TiO(2) = 88 wt%) and Zr2 (PCL=12, ZrO(2) = 88 wt%) hybrid fillers provided better mechanical and biological performances. Conclusions: PCL reinforced with Ti2 (PCL=12, TiO(2) = 88 wt%) and Zr2 (PCL=12, ZrO(2) = 88 wt%) hybrid fillers could be considered as advanced composite substrates for hard tissue engineering.