In this work an innovative method to obtain hybrid bio-functional scaffolds has been developed. Polyether urethane (PU) foam scaffolds were synthetized by one-step gas foaming process. PU foams were coated with crosslinked gelatin hydrogel to promote cell adhesion and proliferation for the regeneration of soft tissues (e.g., adipose tissue). PU foams were coated with inorganic coating (i.e., CaPs) to improve the interaction with osteoblasts for bone tissue regeneration. The functionalized 3D PU porous scaffolds have been characterized investigating morphological properties by SEM and microCT, water uptake and coating stability, and compressive mechanical properties. Adipose tissue derived stem cells (ADSCs), endothelial cells (MS1), amnion mesenchymal cells (AMCs) and chorion mesenchymal cells (CMCs) isolated from human placenta were in vitro cultured on the hybrid functionalized 3D scaffolds. Mechanical properties showed elastic modulus ranging between 15.75 ± 2.14 and 22.9 ± 3.1 kPa; in vitro biological studies showed good cell adhesion, proliferation, and differentiation. In particular, compared to the results with uncoated PU, when cells where differentiated into adipocytes, Oil red O staining confirmed a higher presence of lipid droplets; in case of osteoblasts differentiation, inorganic extracellular matrix deposition was evidenced on CaPs coated PU. The obtained results suggest the important role of an adequate coating on the scaffold to stimulate a better interaction with cells, promoting the differentiation into different cells phenotypes.

Milk whey (MW) represents the major by-product of cheese industry. One possibility to recycle the MW wastes is the use of their globular proteins (MWPs) as a polymer source for the production of biodegradable plastic materials. MWP-based films are usually obtained by protein heat treatment in the presence of glycerol (GLY) as plasticizer at pH 7, a method which would require commercially high costing process. In this work it was exploited the possibility to produce manageable MW-derived biomaterials without any heat-treatment but under alkaline conditions. Our results demonstrated that the casting at pH 12 of the unheated MWP film forming solutions (FFSs), containing either 40% or 50% GLY, led to produce more resistant and flexible biomaterials than the ones obtained at pH 7. Also film transparency was observed significantly improved, being lower in the samples obtained at alkaline pH without MWP heating and with higher GLY concentrations. Finally, moisture content decreased with the reduction of GLY content, both in heated and unheated MWP-based films, whereas water uptake of the different films prepared at pH 12 did not significantly change.

Coatings are a versatile tool for modulation of the biological response of biomaterials; in particular, the use of biopolymers as coating material may improve cell interactions and tissue adhesion. Among others, keratin is a natural protein able to stimulate fibroblast cells effectively and has the ability to bind metal ions. Coatings of keratin fibers onto titanium substrates can improve soft tissue adhesion, eventually coupling topographical (contact guidance) and chemical stimulus through the alignment of the fibers along sub-micrometric grooves of the substrate. Sub-micrometric keratin fibers were obtained by electrospinning both in random and oriented arrangements (though a rotating collector); in addition, antibacterial properties were added by enrichment of the coating with silver ions. This type of coating can be of interest in transmucosal dental implants, where perimplantitis is often due to infection (biofilm formation) and disease worsening is due to inflammation of the surrounding soft tissue, which is guided by fibroblasts. Keratin fibres coatings were prepared and characterized by means of Field Emission scanning electron microscopy (FESEM), X-ray photoelectron spectroscopy (XPS), cell (gingival fibroblasts) and bacteria (S. aureus) culture tests. FESEM observations demonstrated the possibility to deposit keratin fibres onto titanium substrates in random or oriented arrangements effectively. Keratin fibres were able to increase fibroblast adhesion and proliferation. On randomly deposited keratin fibres, fibroblast cells were significantly biologically stimulated and showed high adhesion and proliferation, but not orientation ability; on the other hand, aligned keratin fibres on a grooved substrate were able to stimulate cells both from the topographical (orientation) and biological standpoint. Finally, Ag-doped keratin fibres coatings were able to reduce S. aureus adhesion significantly, maintaining high biocompatibility. Considering these results, keratin sub-micrometric fibres coatings are a promising strategy for stimulating fibroblasts and reducing bacterial contamination.

The most disadvantage of the fried falafel balls are the highest level of acrylamide formed during Maillard reaction. Falafel balls are one of the largest deep fat frying fast food in the Middle East made basically of chickpeas. The main aim of this study was to investigate the effect of adding transglutaminase (TG, E.C. 2.3.2.13) to the falafel dough followed or not by dipping into pectin (PEC 1%) coating solution. Acrylamide, oil and water content of the fried falafel balls treated or not by TG (5 or 20U/g of chickpea proteins) and coated or not with PEC-containing film forming solutions were evaluated. In addition, the texture profile analyses were carried out. We observed, by TOF LC/MS, that the acrylamide content was reduced, compared to control sample, by 10.8% and 34.4% in the samples set up by adding 5 and 20 U TG/g respectively. In PEC-coated samples, acrylamide reduction was about by 59%, 65.3% and 84.5%, in falafel balls prepared either without of TG or containing 5U or 20 U of the enzyme, respectively, suggesting that TG-mediated crosslinks increase the water content inside the falafel balls, thus, reducing the rate of Maillard reaction. However, TG treatment does not affect oil content, while the PEC coating reduces the oil uptake about 23.5%. Finally, no difference was observed between the control sample and the one dipped in PEC regarding their texture properties hardness, chewiness and gumminess, while these properties were influenced in samples set up in the presence of the enzyme.

In this work, the electrospinning technique is used for the synthesis of micro/nanofibers using a polymeric precursor with hydrophobic (even superhydrophobic) behaviour such as polystyrene (PS) or polyvinyl chloride (PVC). These electrospun fibers are deposited onto aluminum substrates (6061T6). The effect of varying the different electrospinning deposition parameters (mostly applied voltage and flow-rate) will be exhaustively analyzed in order to optimize the resultant electrospun coatings. Several fiber characterization tests have been performed, including Field Emission Scanning Electron Microscopy (FE-SEM), Atomic Force Microscopy (AFM), Termogravimetric analysis (TGA), Optical Microscopy (OM) and Water Contact Angle (WCA) measurements. Furthermore, the anti-corrosion properties of these electrospun coatings can be enhanced by the addition of metal oxide nanoparticles (ZnO) which act as corrosion inhibitors. Finally, electrochemical corrosion tests (Tafel and pitting tests) have been perfomed, showing an improvement in the resultant corrosion resistance of the aluminum alloys coated by the combination of both polymeric film with metal oxide inorganic nanoparticles.