Quantitative Study of Morphological Features of Stem Cells onto Photopatterned Azopolymer Films.

In the last decade, the use of photolithography for the fabrication of structured substrates with controlled morphological patterns that are able to interact with cells at micrometric and nanometric size scales is strongly growing. A promising simple and versatile microfabrication method is based on the physical mass transport induced by visible light in photosensitive azobenzene-containing polymers (or azopolymers). Such light-driven material transport produces a modulation of the surface of the azopolymer film, whose geometry is controlled by the intensity and the polarization distributions of the irradiated light. Herein, two anisotropic structured azopolymer films have been used as substrates to evaluate the effects of topological signals on the in vitro response of human mesenchymal stem cells (hMSCs). The light-induced substrate patterns consist of parallel microgrooves, which are produced in a spatially confined or over large-scale areas of the samples, respectively. The analysis of confocal optical images of the in vitro hMSC cells grown on the patterned films offered relevant information about cell morphology-i.e., nuclei deformation and actin filaments elongation-in relation to the geometry and the spatial extent of the structured area of substrates. The results, together with the possibility of simple, versatile, and cost-effective light-induced structuration of azopolymers, promise the successful use of these materials as anisotropic platforms to study the cell guidance mechanisms governing in vitro tissue formation.

Integrating Microstructured Electrospun Scaffolds in an Open Microfluidic System for in Vitro Studies of Human Patient-Derived Primary Cells.

Recent studies have suggested that microenvironmental stimuli play a significant role in regulating cellular proliferation and migration, as well as in modulating self-renewal and differentiation processes of mammary cells with stem cell (SCs) properties. Recent advances in micro/nanotechnology and biomaterial synthesis/engineering currently enable the fabrication of innovative tissue culture platforms suitable for maintenance and differentiation of SCs in vitro. Here, we report the design and fabrication of an open microfluidic device (OMD) integrating removable poly(ε-caprolactone) (PCL) based electrospun scaffolds, and we demonstrate that the OMD allows investigation of the behavior of human cells during in vitro culture in real time. Electrospun scaffolds with modified surface topography and chemistry can influence attachment, proliferation, and differentiation of mammary SCs and epigenetic mechanisms that maintain luminal cell identity as a function of specific morphological or biochemical cues imparted by tailor-made fiber post-treatments. Meanwhile, the OMD architecture allows control of cell seeding and culture conditions to collect more accurate and informative in vitro assays. In perspective, integrated systems could be tailor-made to mimic specific physiological conditions of the local microenvironment and then analyze the response from screening specific drugs for more effective diagnostics, long-term prognostics, and disease intervention in personalized medicine.

An alternative to plaster cast treatment in a pediatric trauma center using the CAD/CAM technology to manufacture customized three-dimensional-printed orthoses in a totally hospital context: a feasibility study.

The aim of this study is to implement the clinical use of the three-dimensional (3D) design and printing technology in pediatric pathologies requiring immobilization. We describe the manufacturing process of the 3D device in place of the plaster cast usually applied to a child 48/72 h after the access to the Trauma Center Traumatology Hub. This procedure had already been performed at Level II, Trauma Center, Campania Region, Orthopaedic Division of Santobono Children's Hospital, Naples, Italy. The operative phase was performed by two 3D printers and a scanner in the bioengineering laboratory of the hospital's outpatient area. The phase of software elaboration requires close cooperation among physicians and engineers. We decided to use a model with a double-shell design and holes varying in width to ensure complete ventilation and lightness of the device. We chose to treat nondisplaced metaphyseal distal fractures of the radius in 18 patients enrolled from January 2017 to November 2017. The flow chart includes clinical and radiological examinations of every enrolled child, collecting information required by the program and its elaboration by bioengineers, and then transfer of the results to 3D printers. The child, immobilized by a temporary splint, wore his 3D device after 12/24 h. Then, he underwent serial check-ups in which the effectiveness and appropriateness of the treatment were clinically monitored and evaluated using subjective scales: visual analogue scale and patient-rated wrist evaluation. All the fractures consolidated both radiologically and clinically after the treatment, with no complications reported. Only one partial breakage of the device happened because of an accidental fall. The statistical analysis of the visual analogue scale and patient-rated wrist evaluation data shows that children's activities of everyday life improved during the immobilization thanks to this treatment. This first study shows that using a 3D device instead of a traditional plaster cast can be an effective alternative approach in the treatment of pediatric nondisplaced metaphyseal distal radius fractures, with high overall patient satisfaction. We believe that 3D technology could be extended to the treatment of more complex fractures; this will be the subject of our second study.

Pure titanium particle loaded nanocomposites: study on the polymer/filler interface and hMSC biocompatibility.

The integration of inorganic nanoparticles into polymer matrices allows for the modification of physical properties as well as the implementation of new features for unexplored application fields. Here, we propose the study of a new metal/polymer nanocomposite fabricated by dispersing pure Ti nanoparticles into a poly(methylmetacrilate) matrix via solvent casting process, to investigate its potential use as new biomaterial for biomedical applications. We demonstrated that Ti nanoparticles embedded in the poly(methylmetacrilate) matrix can act as reinforcing agent, not negatively influencing the biological response of human mesenchymal stem cell in terms of cytotoxicity and cell viability. As a function of relative amount and surface treatment, Ti nanoparticles may enhance mechanical strength of the composite-ranging from 31.1 ± 2.5 to 43.7 ± 0.7 MPa-also contributing to biological response in terms of adhesion and proliferation mechanisms. In particular, for 1 wt% Ti, treated Ti nanoparticles improve cell materials recognition, as confirmed by higher cell spreading-quantified in terms of cell area via image analysis-locally promoting stronger interactions at cell matrix interface. At this stage, these preliminary results suggest a promising use of pure Ti nanoparticles as filler in polymer composites for biomedical applications.