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Chronic wounds (CWs) treatment still represents a demanding medical challenge. Several intrinsic physiological signals (i.e., pH) help to stimulate and support wound healing. CWs, in fact, are characterized by a predominantly alkaline pH of the exudate, which acidifies as the wound heals. Therefore, pH-responsive wound dressings hold great potential owing to their capability of tuning their functions according to the wound conditions. Herein, porous chitosan (CS)-based scaffolds loaded with cellulose nanocrystals (CNCs) and graphene oxide (GO) were successfully fabricated using a freeze-drying method. CNCs were extracted from bagasse pulps fibers through acid hydrolysis. GO was synthesised by Hummer's method. The scaffolds were then ionically cross-linked using the amino acid L-Arginine (Arg), as a bioactive agent, and tested as potential pH-responsive wound dressing. Notably, the effect of CNCs and GO singly and simultaneously loaded within the CS-Arg scaffolds was investigated. The modulation of CNCs and GO content within CS-Arg scaffolds facilitated the development of scaffolds with an optimal pH-dependent swelling ratio capability and extended degradation time. Furthermore, CS/CNC/GO-Arg scaffolds exhibited tuned biological features, in terms of antimicrobial activity, cellular proliferation/migration ability, and the expression of extracellular matrix specific markers (i.e., elastin and collagen I) related to wound healing in human dermal fibroblasts., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper. Stefania Scialla reports financial support was provided by National Research Council. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Author(s). Published by Elsevier B.V. All rights reserved.)

Magnetic scaffolds for bone tissue engineering based on a poly(ε-caprolactone) (PCL) matrix and iron oxide (Fe3O4) magnetic nanoparticles were designed and developed through a three-dimensional (3D) fiber-deposition technique. PCL/Fe3O4 scaffolds were characterized by a 90/10 w/w composition. Tensile and magnetic measurements were carried out, and nondestructive 3D imaging was performed through microcomputed tomography (Micro-CT). Furthermore, confocal analysis was undertaken to investigate human mesenchymal stem cell adhesion and spreading on the PCL/Fe3O4 nanocomposite fibers. The results suggest that nanoparticles mechanically reinforced the PCL matrix; the elastic modulus and the maximum stress increased about 10 and 30%, respectively. However, the maximum strain decreased about 50%; this suggested an enhanced brittleness. Magnetic results evidenced a superparamagnetic behavior for these nanocomposite scaffolds. Micro-CT suggested an almost uniform distribution of nanoparticles. Confocal analysis highlighted interesting results in terms of cell adhesion and spreading. All of these results show that a magnetic feature could be incorporated into a polymeric matrix that could be processed to manufacture scaffolds for advanced bone tissue engineering and, thus, provide new opportunity in terms of scaffold fixation and functionalization. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011 [ABSTRACT FROM AUTHOR]

A basic approach toward the design of three-dimensional (3D) rapid prototyped magnetic scaffolds for hard-tissue regeneration has been proposed. In particular, 3D scaffolds consisting of a poly(ε-caprolactone) (PCL) matrix and iron oxide (Fe3O4) or iron-doped hydroxyapatite (FeHA) nanoparticles were fabricated through a 3D fibre deposition technique. As a first approach, a polymer to nanoparticle weight ratio of 90/10 (wt/wt) was used. The effect of the inclusion of both kinds of nanoparticles on the mechanical, magnetic, and biological performances of the scaffolds was studied. The inclusion of Fe3O4 and FeHA nanoparticles generally improves the modulus and the yield stress of the fibres if compared to those of neat PCL, as well as the modulus of the scaffolds. Micro-computed tomography has confirmed the possibility to design morphologically-controlled structures with a fully interconnected pore network. Magnetisation analyses performed at 37°C have highlighted M-H curves that are not hysteretic; values of saturation magnetisation (Ms) of about 3.9 emu/g and 0.2 emu/g have been evaluated for PCL/Fe3O4 and PCL/FeHA scaffolds, respectively. Furthermore, results from confocal laser scanning microscopy (CLSM) carried out on cell-scaffold constructs have evidenced that human mesenchymal stem cells (hMSCs) better adhered and were well spread on the PCL/Fe3O4 and PCL/FeHA nanocomposite scaffolds in comparison with the PCL structures. [ABSTRACT FROM PUBLISHER]