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. All had regularly-oriented micro-channels (ϕ 500 μm), which differed for the inter-channel spacing, at 600, 700, or 900 μm, respectively. Random-pore scaffolds, using the same technique, were taken as controls. Physical-mechanical characterization revealed high water uptake and favorable elastic mechanical behavior for all scaffolds, slightly reduced in the presence of cross-linking and enhanced with the 700 μm-spaced micro-pattern. At MTT assay, mouse endothelial cell viability was >90% at day 1, 3 and 7, confirmed by visual examination with scanning electron microscopy (SEM). Intra-scaffold cell density, at fluorescence analysis, was higher for the 600 μm-spaced and the 700 μm-spaced micro-patterns over the others. The 700 μm-spaced scaffold was selected for the in vivo testing, to be compared to the random-pore one. Neither type produced an inflammatory reaction; both showed excellent tissue ingrowth. Micro-patterned scaffolds enhanced neo-vascularization, demonstrated by immunofluorescent, semi-quantitative analyses. These findings support the use of micro-patterned porous scaffolds, with adequately spaced micro-channels, to promote neo-vascularization.

Aims: The aim of this study was to develop a new class of gallium (Ga)-doped chitosan (CS) coatings fabricated by electrophoretic deposition (EPD) in staphylococcal infection therapy. Methods and Results: Biofilm formation on EPD CS/Ga coatings by Staphylococcus epidermidis and Staphylococcus aureus, which are the main strains involved in postarthroplasty infections, was assessed. The codeposition of an antibacterial agent was effective; Ga loaded into CS matrix reduces biofilm viability by up to 86% and 80% for S. epidermidis and S. aureus strains respectively. Lastly, the influence of pulsed electromagnetic field (PEMF) on the bactericidal activity of CS/Ga coatings was investigated in vitro. To this end, the coatings were incubated with S. epidermidis and S. aureus and exposed to the PEMF using two different frequencies and times. Biofilm viability for S. epidermidis was decreased by 35-40% in the presence of lowfrequency (LF) and high-frequency (HF) PEMF respectively. Biofilm viability by S. aureus was not further reduced in the presence of LF PEMF, but decreased by 38% at HF PEMF. Conclusions: This study has established that a combination of PEMFs with the antibacterial agent improves bactericidal activity of Ga against S. epidermidis strain 14990 and S. aureus strain 12600. Significance and Impact of the Study: This new integrated approach could reduce the incidence of infection in orthopaedic implant applications. It also clearly demonstrates that the combination of Ga treatment with PEMF could aid biofilm-associated infection therapy due to improved Ga efficiency.Preparation and chemico-physical characterization of CS/Ga composite coating EPD of CS/Ga composite coating Titanium sheets (Ti, grade 2) were used as the cathode in an EPD cell: electrodes were positioned at a distance of 10 mm (Isfahani and Ghorbani 2013) in a lab-made EPD Journal of Applied Microbiology 126, 87--101

One of the main challenges in the design of scaffolds for cortical bone regeneration is mimicking the highly oriented, hierarchical structure of the native tissue in an efficient, simple, and consistent way. As a possible solution to this challenge, positive replica based on electrophoretic deposition (EPD) was here evaluated as a technique to produce organic/inorganic scaffolds with oriented micro‐porosities mimicking Haversian canals diameter and spacing. Two different sizes of 45S5 bioactive glass (BG) powders were chosen as inclusions and loaded in a chitosan matrix via EPD on micro‐patterned cathodes. Self‐standing chitosan scaffolds, with a homogeneous dispersion of BG particles and regularly‐oriented micro‐channels (ϕ = 380 ± 50 μm, inter‐channel spacing = 600 ± 40 μm), were obtained. In vitro analysis in simulated body fluid (SBF) revealed the ability to induce a deposition of a homogenous layer of hydroxyapatite (HA), with Ca/P nucleation reactions appearing kinetically favored by smaller BG particles. Cell interaction with hybrid scaffolds was evaluated in vitro with bone osteosarcoma cells (SAOS‐2). The osteoconductive potential of EPD structures was assessed by evaluating cells proliferation, viability and scaffold colonization. Results indicate that EPD is a simple yet extremely effective technique to prepare composite micro‐patterned structures and can represent a platform for the development of a new generation of bone scaffolds. © 2019 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2019.

Clobetasol propionate (CP) is a high-potency corticosteroid, representing the standard of care for the symptomatic treatment of different skin disorders as well as oral cavity diseases. Several topical delivery systems are available in oral lesion care, but the ideal one is still lacking, being serious side-effects still reported. In this work, we propose a novel class of chitosan (CS) patches, loaded with CP, for the topical treatment of inflammatory chronic oral muco-cutaneous diseases. Chitosan patches have been fabricated via electrophoretic deposition (EPD), by using a one-pot approach in order to load controlled quantity of CP. Optimized structures showed a water uptake in the range of 200-360% and mechanical properties that allow the design of flexible patches in wet state (E = 0.6 MPa and δbr = 0.55 MPa). Ultraviolet-visible (UV-Vis) spectroscopy was used for the evaluation of both loading and release profile of CP in CS patches. The CP loading has been tuned by adjusting CP concentration in deposition bath-in the range 0.002 to 0.12 mg cm-² while releasing curves show an in vitro CP burst of about 80% in the first two hours. Overall, the obtained properties paved the way for the application of this new class of patches for the local oral release of CP. Keywords Electrophoretic deposition (EPD); Hierarchical patches; Chitosan; Clobetasol propionate; Topical oral drug delivery. Response to Reviewers: The PDF file has been attached to the "attach Files" section: Comments to reviewer 1. We would like to thank again the reviewer for her/his invaluable effort in reviewing the paper. Comments have been very useful in improving the overall quality of the text.