Modulable properties of PVA/cellulose fiber composites.

Purpose:: Development of PVA/cellulose fiber composite material with modulable properties, obtained through the increase of reinforcement and heat treatments in order to optimize the composite in terms of mechanical, thermal, and degradation properties.

Methods:: The composite was designed selecting as matrix an experimental formulation based on water-soluble, biodegradable, polyvinyl alcohol (PVA) and microcrystalline cellulose (MCC), as reinforcement. Six different formulations, with increasing ratio of MCC content (from 0% to 55% w/w) in PVA, were developed and extruded by a co-rotating twin-screw extruder (TSA FSCM 21/40).

Development of a photocatalytic filter to control indoor air quality.

Background: The aim of this work was the development and characterization of a photocatalytic filter for the treatment of indoor air, characterized by a low pressure drop.

Methods: The filter (photocatalytic filter) was based on a polyester substrate additivated with active carbon (Carbotex 150-6), treated with a sol of titanium dioxide (Sol 121-AB; NextMaterials Ltd.) and illuminated with UV LEDs to induce photocatalytic activity.

Poly-paper: a sustainable material for packaging, based on recycled paper and recyclable with paper.

Background: Until now, environmental sustainability issues are almost entirely unsolved for packaging materials. With the final aim of finding materials with a single recycling channel, cellulose fiber/poly(vinyl)alcohol composites were investigated.

Methods: After extrusion and injection molding, samples of composite with different cellulose fiber content (30%, 50% and 70% w/w) were tested.

Hierarchic micro-patterned porous scaffolds via electrochemical replica-deposition enhance neo-vascularization.

Neo-vascularization is a key factor in tissue regeneration within porous scaffolds. Here, we tested the hypothesis that micro-patterned scaffolds, with precisely-designed, open micro-channels, might help endothelial cells to produce intra-scaffold vascular networks. Three series of micro-patterned scaffolds were produced via electrochemical replica-deposition of chitosan and cross-linking.

Tribological and mechanical performance evaluation of metal prosthesis components manufactured via metal injection molding.

The increasing number of total joint replacements, in particular for the knee joint, has a growing impact on the healthcare system costs. New cost-saving manufacturing technologies are being explored nowadays. Metal injection molding (MIM) has already demonstrated its suitability for the production of CoCrMo alloy tibial trays, with a significant reduction in production costs, by holding both corrosion resistance and biocompatibility.

Hydrogel-based nanocomposites and mesenchymal stem cells: a promising synergistic strategy for neurodegenerative disorders therapy.

Hydrogel-based materials are widely employed in the biomedical field. With regard to central nervous system (CNS) neurodegenerative disorders, the design of injectable nanocomposite hydrogels for in situ drug or cell release represents an interesting and minimally invasive solution that might play a key role in the development of successful treatments. In particular, biocompatible and biodegradable hydrogels can be designed as specific injectable tools and loaded with nanoparticles (NPs), to improve and to tailor their viscoelastic properties upon injection and release profile.

Development and analysis of semi-interpenetrating polymer networks for brain injection in neurodegenerative disorders.

Purpose: Our aim was to assess the use of injectable, biocompatible and resorbable, hydrogel-based tools for innovative therapies against brain-related neurodegenerative disorders like Alzheimer's (AD) and Parkinson's (PD) diseases.

Methods: Two compositions of semi-interpenetrating polymer networks (semi-IPNs) based on collagen and poly(ethylene glycol) (PEG) were investigated. We examined their viscoelastic properties, flow behavior, functional injectability, as well as in vitro biocompatibility with SH-SY5Y human neuroblastoma cells and murine primary neurons.

Metal injection molding as enabling technology for the production of metal prosthesis components: electrochemical and in vitro characterization.

Industrial manufacturing of prosthesis components could take significant advantage by the introduction of new, cost-effective manufacturing technologies with near net-shape capabilities, which have been developed during the last years to fulfill the needs of different technological sectors. Among them, metal injection molding (MIM) appears particularly promising for the production of orthopedic arthroplasty components with significant cost saving. These new manufacturing technologies, which have been developed, however, strongly affect the chemicophysical structure of processed materials and their resulting properties.

Electrochemically deposited gentamicin-loaded calcium phosphate coatings for bone tissue integration.

Purpose: Despite improvements in operative environment and surgical techniques, post-operative infections remain one of the most devastating complications in total joint replacement prostheses. Several efforts have been made to modify the surface of materials in order to prevent bacterial adhesion and colonization. Here, we show a one-pot electrochemical surface modification process for co-deposition of calcium phosphate and gentamicin, with the aim of triggering specific biological responses and imparting antibacterial properties on titanium alloy prostheses.

A novel antibacterial modification treatment of titanium capable to improve osseointegration.

Background: Among the different causes of orthopedic and dental implant failure, infection remains the most serious and devastating complication associated with biomaterial devices.

Purpose: The aim of this study was to develop an innovative osteointegrative and antibacterial biomimetic coating on titanium and to perform a chemical-physical and in vitro biological characterization of the coating using the SAOS-2 cell line. We also studied the antibacterial properties of the coating against both Gram-positive and Gram-negative bacteria strains.

Improving indoor air quality by using the new generation of corrugated cardboard-based filters.

Purpose: Indoor Air Quality (IAQ) is strictly affected by the concentration of total suspended particulate matter (TSP). Air filtration is by far the most feasible suggestion to improve IAQ. Unfortunately, highly effective HEPA filters also have a few major weaknesses that have hindered their widespread use.

Preparation and characterization of shape memory polymer scaffolds via solvent casting/particulate leaching.

Purpose: Porous Shape Memory Polymers (SMPs) are ideal candidates for the fabrication of defect fillers, able to support tissue regeneration via minimally invasive approaches. In this regard, control of pore size, shape and interconnection is required to achieve adequate nutrient transport and cell ingrowth. Here, we assessed the feasibility of the preparation of SMP porous structures and characterized their chemico-physical properties and in vitro cell response.

A novel silicon-based electrochemical treatment to improve osteointegration of titanium implants.

Background: Titanium and its alloy represent the most commonly used biomaterials worldwide designed for bone-contact under-load applications, which often require specific mechanical properties. In particular, a large number of different biomimetic surface treatments have been developed to speed up the osteointegration process, which facilitates a reduction in recovery time.

Purpose: The aim of this work is to investigate the physical-chemical, mechanical and bioactivity properties of an innovative biomimetic treatment on titanium performed using Anodic Spark Deposition (ASD) electrochemical treatment.

Nanocomposites for neurodegenerative diseases: hydrogel-nanoparticle combinations for a challenging drug delivery.

Neurodegenerative disorders are expected to strike social and health care systems of developed countries heavily in the coming decades. Alzheimer's and Parkinson's diseases (AD/PD) are the most prevalent neurodegenerative pathologies, and currently their available therapy is only symptomatic. However, innovative potential drugs are actively under development, though their efficacy is sometimes limited by poor brain bioavailability and/or sustained peripheral degradation.

Development of novel cardboard filters very effective in removing airborne bacteria from confined environments.

Purpose: Since bacterial pollution is more troublesome than other nonbiologic air pollutants, the need to control airborne micro-organisms has led to renewed interest in filter media for air filtration in indoor environments. Although mechanical filtration of aerosols by HEPA systems is the most common method for particle removal, these filters characterized by high efficiency usually reveal a higher drop in pressure and noise and are very expensive. On this basis, we aimed to develop novel, very effective air filters for removal of airborne bacteria from confined environments.

Titanium oxide antibacterial surfaces in biomedical devices.

Titanium oxide is a heterogeneous catalyst whose efficient photoinduced activity, related to some of its allotropic forms, paved the way for its widespread technological use. Here, we offer a comparative analysis of the use of titanium oxide as coating for materials in biomedical devices. First, we introduce the photoinduced catalytic mechanisms of TiO2 and their action on biological environment and bacteria.

Trends in biomedical engineering: focus on Smart Bio-Materials and Drug Delivery.

The present article reviews on different research lines, namely: drug and gene delivery, surface modification/modeling, design of advanced materials (shape memory polymers and biodegradable stents), presently developed at Politecnico di Milano, Italy. For gene delivery, non-viral polycationic-branched polyethylenimine (b-PEI) polyplexes are coated with pectin, an anionic polysaccharide, to enhance the polyplex stability and decrease b-PEI cytotoxicity. Perfluorinated materials, specifically perfluoroether, and perfluoro-polyether fluids are proposed as ultrasound contrast agents and smart agents for drug delivery.

Electrochemically induced anatase inhibits bacterial colonization on Titanium Grade 2 and Ti6Al4V alloy for dental and orthopedic devices.

Bacterial contamination of implanted devices is a common cause of their failure. The aim of the present study was to assess the capability of electrochemical procedures to: (a) promote the formation of anatase on the surface of commercially pure Grade 2 Ti and Ti Grade 5 (Ti6Al4V) alloy; (b) inhibit in vitro biofilm formation of Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus mutans and Porphyromonas gingivalis and oral plaque in vivo, (c) preserve favorable response of osteoblasts and fibroblasts to materials surfaces. Ti Grade 2 and Ti Grade 5 were respectively anodized at two different voltages: 90 and 130V for pure titanium; 100 and 120V for Ti6Al4V alloy.

The ceramic-on-metal coupling in total hip replacements for young patients: a review study.

In the last two decades the performance of total hip replacements (THR) has constantly improved, thanks largely to advances in the field of material science and technology. Although contemporary devices are clinically very reliable, some problems still need to be addressed: the wear of ultra high molecular weight polyethylene components, the release of metal ions from metal-on-metal joints, the toughness of the ceramic cups and the possibility of squeaking for ceramic-on-ceramic couplings. All these drawbacks become particularly relevant in case of THR for young and active patients, when the life expectancy of the orthopedic device is very high and the possibility of mechanical shocks is not negligible.

Anodic Spark Deposition treatments to increase reliability of Ti6Al4V modular prostheses.

Purpose: The aim of this study was to evaluate whether an Anodic Spark Deposition treatment, which assures increased resistance of titanium alloys to fretting corrosion, improves the structural reliability of Ti6Al4V modular hip prostheses, thus preventing the recently noticed in vivo mechanical failures of these components due to fatigue events.

Methods: Three commercial treatments were tested in this work. Microhardness, roughness and fatigue resistance measurements were carried out to investigate the treatment performances.

Multidisciplinary perspectives for Alzheimer's and Parkinson's diseases: hydrogels for protein delivery and cell-based drug delivery as therapeutic strategies.

This review presents two intriguing multidisciplinary strategies that might make the difference in the treatment of neurodegenerative disorders such as Alzheimer's and Parkinson's diseases. The first proposed strategy is based on the controlled delivery of recombinant proteins known to play a key role in these neurodegenerative disorders that are released in situ by optimized polymer-based systems. The second strategy is the use of engineered cells, encapsulated and delivered in situ by suitable polymer-based systems, that act as drug reservoirs and allow the delivery of selected molecules to be used in the treatment of Alzheimer's and Parkinson's diseases.

Shape memory polymer foams for cerebral aneurysm reparation: effects of plasma sterilization on physical properties and cytocompatibility.

Shape memory polyurethanes (SMPUs) represent promising candidate materials for aneurysm embolization, since they could enable clinical problems still associated with these clinical procedures to be overcome. In this work, we report on the characterization of physicochemical, thermomechanical and in vitro interface properties of two SMPU foams (Cold Hibernated Elastic Memory, CHEM), proposed as a material for embolization devices in minimally invasive procedures. Moreover, because device sterilization is mandatory for in vivo applications, effects on the properties of the foams after plasma sterilization were also evaluated.

Apatite formation and cellular response of a novel bioactive titanium.

The modification of titanium and titanium alloy surface properties by chemical and electrochemical techniques has opened new possibilities to improve the bioactivity and, in general, the biological performance of the implants once in vivo. One of the main aims is the achievement of a surface oxide layer that stimulates hydroxylapatite mineralization and, also, shows osteoconductive properties once in the host. In the present study, two different bioactive surfaces have been prepared following the method purposed by the group of Kokubo and a new method, BioSpark, involving high voltage anodic polarisation and alkali etching both on surface mineralization potential.

Physical and biological characterizations of a novel multiphase anodic spark deposition coating to enhance implant osseointegration.

The present study assessed in vitro the short-term cellular response to surface physico-chemical properties of a new, purposed bioactive surface treatment called BioSpark performed on simply machined and on sand-blasted titanium. Material characterisation was carried out using scanning electron microscopy, energy dispersion spectroscopy, laser profilometry, and thin film X-ray diffraction. The in vitro biological study showed a suitable cellular response with adhesion and spreading level comparable for all the tested specimens.