1,721,066 research outputs found
Wet-spinning of biomedical polymers: From single-fibre production to additive manufacturing of three-dimensional scaffolds
No full textWet-spinning of polymeric materials has been widely investigated for various biomedical applications, such as extracorporeal blood treatment, controlled drug release and tissue engineering. This review is aimed at summarizing and assessing current advances in wet-spinning of biomedical polymers to manufacture single fibres and three-dimensional scaffolds, as well as their functionalization through loading with bioactive agents. The theoretical principles and the main technological aspects of fibre production by wet-spinning on either a laboratory or an industrial scale are outlined. The non-solvent-induced phase inversion determining polymer coagulation during the wet-spinning process is discussed by highlighting its influence on the resulting fibre morphology and how it can be exploited to induce a nano/microporosity in the solidified polymeric matrix. The versatility of wet-spinning in material selection, bioactive agent loading and fibre morphology tuning is underlined through an overview of significant literature reporting on the processing of various naturally derived and synthetic polymers. A special focus is given to cutting-edge advancements in the application of additive manufacturing principles to wet-spinning for enhanced control and reproducibility of three-dimensional polymeric scaffold morphology at different scale levels (i.e. macrostructural to micro/nanostructural features)
Customized Approaches for the Biomedical Application of Polymers
No full textThe present contribution aims at providing information on relevant cases of integrated research activities with a high potential for biomedical and healthcare applications. This overview is essentially based on the follow-ups of the EC-funded projects EU/FP7 NANOTHER CP-IP 213631-2, SKINTREAT CP-TP 213202-2; HYANJI SCAFFOLD PIRSES-GA-2008- 230791; EU/FP6 NoE EXPERTISSUES NMP3-CT-2004-500283 and REGIONE LOMBARDIA funded project (2009, 2013
Procedimento e Dispositivo di Filatura a Umido Assistita da Computer per la Produzione di Stent Polimerici
No full textPolysaccharide-based polyelectrolyte complexes for biomedical applications
No full textThe chapter will focus on the preparation and characterization of polyelectrolyte complexes based on polysaccharides obtained from renewable and sustainable resources. Different strategies to fabricate micro/nanostructured PECs will also be presented with a special focus on additive manufacturing techniques. The biomedical applications that will be discussed will comprise PECs for regenerative medicine (e.g., bone tissue engineering) and as 3D in vitro culture model closely resembling the in vivo microenvironment of both pathologic (e.g., cancer tissue) and normal tissues
Additive manufacturing of star poly(ε-caprolactone) wet-spun scaffolds for bone tissue engineering applications
Full text linkThree-dimensional fibrous scaffolds made of a three-arm star poly(ε-caprolactone) were developed by employing a novel computer-aided wet-spinning apparatus to precisely control the deposition pattern of an extruded polymeric solution as a filament into a coagulation bath. Star poly(ε-caprolactone)/hydroxyapatite composite scaffolds composed of fibres with a porous morphology both in the outer surface and in the cross section were successfully produced with a layer-by-layer approach achieving good reproducibility of the internal architecture and external shape. Changes in processing parameters were used to fabricate scaffolds with different architectural parameters in terms of average pore size in the xy-axes (from 190 to 297 μm) and in the z-axis (from 54 to 126 μm) and porosity (in the range of 20%–60%). Based on the mechanical characterization, processing variations and hydroxyapatite loading have an influence on scaffold compression properties. Cell cultures, using a murine pre-osteoblast cell line, had good cell responses in terms of proliferation and osteoblastic differentiation. Thus, this technique appears to be an effective method for producing customized polymeric scaffolds for bone tissue engineering applications
Melt‐Versus Solution‐Extrusion Additive Manufacturing of Poly(methyl methacrylate) Medical Implant Prototypes
No full textPolymeric Materials for Bone and Cartilage Repair
No full textThe past decade has seen the rapid development of new strategies for the design of biodegradable macromolecular compounds, with properly suited architecture and tailored properties, functioning as temporary support for the engineering of living constructs in tissue regeneration applications. The purpose of this paper is to review recent research in the interdisciplinary field of tissue engineering, with particular regard to bone and cartilage tissues, aimed at the design, synthesis, evaluation and characterization of bioactive polymeric scaffolds guiding and promoting new tissue ingrowth. Current strategies in scaffold-guided tissue engineering approach, involving the most employed biodegradable polymers, either of natural or synthetic origin, will be reported underlying the role played by both material structure-property relationship and scaffold architecture. While there are many polymeric materials that may be employed for the regeneration of bone and cartilage tissue, we will focus specifically on those that have been more extensively applied, showing promising outcomes. Commonly exploited and innovative processing techniques for the fabrication of advanced tissue engineering scaffolds will be explored, highlighting theoretical principles and their potential in creating micro-nanostructures suitable for tissue regeneration application
Additive manufacturing techniques for the production of tissue engineering constructs
Full text link'Additive manufacturing' (AM) refers to a class of manufacturing processes based on the building of a solid object from three-dimensional (3D) model data by joining materials, usually layer upon layer. Among the vast array of techniques developed for the production of tissue-engineering (TE) scaffolds, AM techniques are gaining great interest for their suitability in achieving complex shapes and microstructures with a high degree of automation, good accuracy and reproducibility. In addition, the possibility of rapidly producing tissue-engineered constructs meeting patient's specific requirements, in terms of tissue defect size and geometry as well as autologous biological features, makes them a powerful way of enhancing clinical routine procedures. This paper gives an extensive overview of different AM techniques classes (i.e. stereolithography, selective laser sintering, 3D printing, melt-extrusion-based techniques, solution/slurry extrusion-based techniques, and tissue and organ printing) employed for the development of tissue-engineered constructs made of different materials (i.e. polymeric, ceramic and composite, alone or in combination with bioactive agents), by highlighting their principles and technological solution
Functionalized Hydroxyapatite Loading Enhances the Mechanical and Biodegradation Properties of Wet‐Spun Poly(Lactide‐co‐Glycolide) Scaffolds by Additive Manufacturing
No full textAdditive manufacturing of biodegradable composite materials is an effective strategy for the development of tailored scaffolds for bone tissue engineering. This research activity is aimed at the development of poly(D,L-lactide-co-glycolide) (PLGA) scaffolds loaded with hydroxyapatite (HA) by means of a novel additive manufacturing approach. For this purpose, HA particles are functionalized through PLGA grafting (PgHA) to increase their compatibility with the polymeric matrix. PgHA-loaded PLGA scaffolds show higher tensile and compressive moduli than analogous PLGA scaffolds non-loaded with the ceramic phase, as well as a higher elongation at break than PLGA scaffolds loaded with non-functionalized HA. In addition, PgHA-loaded scaffolds maintain their structural stability in vitro for a longer time (9 weeks) than the other two kinds of scaffold. All the developed scaffolds support in vitro preosteoblast viability and differentiation toward the osteoblastic phenotype. The obtained results encourage therefore future research on the developed composite scaffolds for personalized bone tissue engineering approaches
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