Materials Education and Research in Art and Design: A New Role for Libraries - Session 3. RISD Faculty

Faculty from Rhode Island School of Design representing Interior Architecture, Industrial Design, and Textiles detail their thoughtful interactions with materials.

Materials Education and Research in Art and Design: A New Role for Libraries - Session 4. Designers

Designers respond to issues and synthesize ideas from throughout the day as voices from the field who directly encounter the need for recently graduated students to possess the ability to investigate and interrogate materials.

Materials Education and Research in Art and Design: A New Role for Libraries - Session 2. Educators

Educators representing interactions with materials speak to critical approaches, life-cycle concerns, critical thinking of composition/process/properties.

Characterization and in vitro evaluation of bacterial cellulose membranes functionalized with osteogenic growth peptide for bone tissue engineering

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

On the control of a non-ideal engineering system: A friction-driven oscillating system with limited power supply

In this work a switching feedback controller for stick-slip compensation of a 2-DOF mass-spring-belt system which interacts with an energy source of limited power supply (non-ideal case) is developed. The system presents an oscillatory behavior due to the stick-slip friction. As the system equilibrium for a conventional feedback controller is not the origin, a switching control law combining a state feedback term and a discontinuous term is proposed to regulate the position of the mass. The problem of tracking a desired periodic trajectory is also considered. The feedback system is robust with respect to the friction force that is assumed to be within known upper and lower bounds.

Nanostructured materials based on mesoporous silica and mesoporous silica/apatite as osteogenic growth peptide carriers

The aim of this work was the preparation of inorganic mesoporous materials from silica, calcium phosphate and a nonionic surfactant and to evaluate the incorporation and release of different concentrations of osteogenic growth peptide (OGP) for application in bone regeneration. The adsorption and release of the labeled peptide with 5,6-carboxyfluorescein (OGP-CF) from the mesoporous matrix was monitored by fluorescence spectroscopy. The specific surface area was 880 and 484 m2 g- 1 for pure silica (SiO) and silica/apatite (SiCaP), respectively; the area influenced the percentage of incorporation of the peptide. The release of OGP-CF from the materials in simulated body fluid (SBF) was dependent on the composition of the particles, the amount of incorporated peptide and the degradation of the material. The release of 50% of the peptide content occurred at around 4 and 30 h for SiCaP and SiO, respectively. In conclusion, the materials based on SiO and SiCaP showed in vitro bioactivity and degradation; thus, these materials should be considered as alternative biomaterials for bone regeneration. © 2013 Elsevier B.V.

Stress analysis in bone tissue around single implants with different diameters and veneering materials: A 3-D finite element study

The aimof this study was to evaluate the stress distribution on bone tissue with a single prosthesis supported by implants of large and conventional diameter and presenting different veneering materials using the 3-D finite elementmethod. Sixteenmodels were fabricated to reproduce a bone block with implants, using two diameters (3.75 × 10 mmand 5.00 × 10 mm), four different veneering materials (composite resin, acrylic resin, porcelain, and NiCr crown), and two loads (axial (200 N) and oblique (100 N)). For data analysis, the maximum principal stress and vonMises criterion were used. For the axial load, the cortical bone in allmodels did not exhibit significant differences, and the trabecular bone presented higher tensile stresswith reduced implant diameter. For the oblique load, the cortical bone presented a significant increase in tensile stress on the same side as the loading for smaller implant diameters. The trabecular bone showed a similar but more discreet trend. There was no difference in bone tissue with different veneering materials. The veneering material did not influence the stress distribution in the supporting tissues of single implant-supported prostheses. The large-diameter implants improved the transference of occlusal loads to bone tissue and decreased stress mainly under oblique loads.Oblique loading was more detrimental to distribution stresses than axial loading. © 2013 Elsevier B.V. All rights reserved.

The physicochemical characterization and in vivo response of micro/nanoporous bioactive ceramic particulate bone graft materials

In this study, the physicochemical characteristics of calcium phosphate based bioactive ceramics of different compositions and blends presenting similar micro/nanoporosity and micrometer scale surface texture were characterized and evaluated in an in vivo model. Prior to the animal experiment, the porosity, surface area, particle size distribution, phase quantification, and dissolution of the materials tested were evaluated. The bone regenerative properties of the materials were evaluated using a rabbit calvaria model. After 2, 4, and 8 weeks, the animals were sacrificed and all samples were subjected to histologic observation and histomorphometric analysis. The material characterization showed that all materials tested presented variation in particle size, porosity and composition with different degrees of HA/TCP/lower stoichiometry phase ratios. Histologically, the calvarial defects presented temporal bone filling suggesting that all material groups were biocompatible and osteoconductive. Among the different materials tested, there were significant differences found in the amount of bone formation as a function of time. At 8 weeks, the micro/nanoporous material presenting similar to 55,TCP:45%,HA composition ratio presented higher amounts of new bone regeneration relative to other blends and a decrease in the amount of soft tissue infiltration. (C) 2014 Elsevier B.V. All rights reserved.

PbO-GeO2 rare earth doped glasses with silver nanoparticles as materials for IR laser triggers

We have shown the possibility of operation by the piezooptical response of PbO-GeO2 glasses doped with rare earth ions and silver nanoparticles by illumination of double frequency CO2 nanosecond laser. Substantial influence of thermoannealing on the output photoinduced elastooptical susceptibilities was established. The effect is very sensitive to temperature and to the corresponding tensor components. The effect of thermoannealing leads to enhanced long-range ordering with the occurrence of corresponding trapping levels within the forbidden gaps. The discovered effects may be used for creation of low-temperature IR laser triggers.

Characterization and in vitro evaluation of bacterial cellulose membranes functionalized with osteogenic growth peptide for bone tissue engineering

The aim of this study was to characterize the physicochemical properties of bacterial cellulose (BC) membranes functionalized with osteogenic growth peptide (OGP) and its C-terminal pentapeptide OGP[10-14], and to evaluate in vitro osteoinductive potential in early osteogenesis, besides, to evaluate cytotoxic, genotoxic and/or mutagenic effects. Peptide incorporation into the BC membranes did not change the morphology of BC nanofibers and BC crystallinity pattern. The characterization was complemented by Raman scattering, swelling ratio and mechanical tests. In vitro assays demonstrated no cytotoxic, genotoxic or mutagenic effects for any of the studied BC membranes. Culture with osteogenic cells revealed no difference in cell morphology among all the membranes tested. Cell viability/proliferation, total protein content, alkaline phosphatase activity and mineralization assays indicated that BC-OGP membranes enabled the highest development of the osteoblastic phenotype in vitro. In conclusion, the negative results of cytotoxicity, genotoxicity and mutagenicity indicated that all the membranes can be employed for medical supplies, mainly in bone tissue engineering/regeneration, due to their osteoinductive properties.

Bacterial cellulose-collagen nanocomposite for bone tissue engineering

A nanocomposite based on bacterial cellulose (BC) and type I collagen (COL) was evaluated for in vitro bone regeneration. BC membranes were modified by glycine esterification followed by cross-linking of type I collagen employing 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide. Collagen incorporation was studied by spectroscopy analysis. X-Ray diffraction showed changes in the BC crystallinity after collagen incorporation. The elastic modulus and tensile strength for BC-COL decreased, while the strain at failure showed a slight increase, even after sterilization, as compared to pristine BC. Swelling tests and contact angle measurements were also performed. Cell culture experiments performed with osteogenic cells were obtained by enzymatic digestion of newborn rat calvarium revealed similar features of cell morphology for cultures grown on both membranes. Cell viability/proliferation was not different between BC and BC-COL membranes at day 10 and 14. The high total protein content and ALP activity at day 17 in cells cultured on BC-COL indicate that this composite allowed the development of the osteoblastic phenotype in vitro. Thus, BC-COL should be considered as alternative biomaterial for bone tissue engineering.