35 research outputs found
Biomimetic air-liquid interface milli-bioreactor for skin tissue engineering applications
No full textSelf-standing gelatin- methacryloyl 3D structure using Carbopol-embedded printing
No full textGelatin-methacryloyl (GelMA) hydrogel has gained huge success in the lastdecades thanks to its versatilities in many applications. Notably, one of them is3D bioprinting, as GelMA physical-mechanical properties and biocompatibilityof uncured formulation perfectly suit the requirements of a bioink. Neverthe-less, before the photopolymerization, the hydrogel shows weak mechanicalproperties and long recovery time after stress application, which results in theinability to obtain complex and self-standing forms due to structure collapse.In this work, Carbopol ETD 2020 NF, dissolved in cell culture medium, wasused as supporting bath to optimize GelMA bioprinting and overcome its sta-bility limitations. The achieved results demonstrated the possibility of printingshapes containing hollows with lumens or non-planar surfaces, also by usingnozzles with larger inner diameter, which reduced cell death during printingprocess, but were usually avoid because of low resolution. Moreover, con-structs' extraction was easier when Carbopol solution was prepared in culturemedium rather than in water, reducing sample handling. In conclusion,thanks to this supporting bath, it was possible to print cellularized scaffold,with channels that were then seeded, obtaining inner structure. Further, thisCarbopol formulation could be considered an eligible candidate as a support-ing bath to obtain GelMA 3D self-standing-shaped and vascularized scaffold
Printability study by selective laser sintering of bio-based samples obtained by using PBS as polymeric matrix
No full textThe emerging request to reduce the environmental impact of plastics encourages scientists to use novel sustainable
polymeric materials for many applications fields.
The present paper aims to use for the first-time poly (butylene succinate) (PBS), a biodegradable and compostable
polymer, for Selective Laser Sintering (SLS) applications. PBS is a flexible semicrystalline aliphatic
polyester, which can represent a very good alternative to the traditional thermoplastic polymers obtained by
fossil sources.
The present work started from a lab-scale production of PBS powders by means of an emulsion solvent
evaporation/precipitation method, with the purpose to increase the number of polymeric powders available for
SLS. The obtained PBS powders were first characterized by morphological and thermal point of view, and then
employed as innovative polymeric material in SLS to realized 3D printed parts with increasing geometrical
complexity. To confirm PBS cytocompatibility, cell proliferation and cell viability assays (MTT and Live&Dead)
were measured using a lung adenocarcinoma epithelial cell line (H1299). The in vitro cytotoxicity of the 3D
printed material was also investigated, showing no harm on cells
GelMA synthesis and sources comparison for 3D multimaterial bioprinting
No full textGelatin Methacryloyl (GelMA) is one of the most used biomaterials for a wide range of applications, such as drug delivery, disease modeling and tissue regeneration. GelMA is obtained from gelatin, which can be derived from different sources (e.g., bovine skin, and porcine skin), through substitution of reactive amine and hydroxyl groups with methacrylic anhydride (MAA). The degree of functionalization (DoF) can be tuned by varying the MAA amount used; thus, different protocols, with different reaction efficiency, have been developed, using various alkaline buffers (e.g., phosphate-buffered saline, DPBS, or carbonate-bicarbonate solution). Obviously, DoF modulation has an impact on the final GelMA properties, so a deep investigation on the features of the obtained hydrogel must be carried on. The purpose of this study is to investigate how different gelatin sources and synthesis methods affect GelMA properties, as literature lacks direct and systematic comparisons between these parameters, especially between synthesis methods. The final aim is to facilitate the choice of the source or synthesis method according to the needs of the desired application. Hence, chemical and physical properties of GelMA formulations were assessed, determining the DoFs, mechanical and viscoelastic properties by rheological analysis, water absorption by swelling capacity and enzymatic degradation rates. Biological tests with lung adenocarcinoma cells (A549) were performed. Moreover, since 3D bioprinting is a rapidly evolving technology thanks to the possibility of precise deposition of cell-laden biomaterials (bioinks) to mimic the 3D structures of several tissues, the potential of different GelMA formulations as bioinks have been tested with a multi-material approach, revealing its printability and versatility in various applications
BIOMIMETIC BIOREACTOR FOR AIR-LIQUID INTERFACE CULTURE - SKIN TISSUE ENGINEERING APPLICATION
No full textMethodology for Comparing Viscoelastic and Poroelastic Properties of GelMA Hydrogels at the Cellular Scale
No full text3D-printed cell culture system as an in vitro platform for non-small cell lung cancer (NSCLC) modeling
No full textA Methodological Approach for Interpreting and Comparing the Viscoelastic Behaviors of Soft Biological Tissues and Hydrogels at the Cell-Length Scale
No full textThe behavior of a cell is strongly influenced by the physical properties and stimuli in its microenvironment. Furthermore, the activation and modulation of mechanotransduction pathways are involved in tissue development and homeostasis and even pathological processes. Thus, when developing materials aimed at mimicking the extracellular matrixes of healthy or pathological tissues, their mechanical features should be closely considered. In this context, nanoindentation represents a powerful technique for mechanically characterizing biological tissues and hydrogels at the cell-length scale. However, standardized experimental protocols and data analysis techniques are lacking. Here, we proposed a methodological approach based on the nanoindentation technique for quantitatively analyzing and comparing the time-dependent load relaxation responses of soft biological tissues and hydrogels. As this was an explanatory study, stress-relaxation nanoindentation tests were performed on samples of pig and human lung tissues and of a specific gelatin-methacryloyl (GelMA) hydrogel to quantify and compare their viscoelastic properties. The proposed method allowed for identifying the characteristic parameters needed for describing the behavior of each sample, permitting us to quantitatively compare their mechanical behaviors. All samples showed load relaxation at a defined indentation depth because of their intrinsic viscoelastic behaviors, and the GelMA samples showed the highest relaxation capabilities. The distribution of the characterization parameters showed that the biological samples presented similar time-dependent responses, while differences were observed in the GelMA samples. Overall, the proposed methodological approach allows for providing key insights into the time-dependent behaviors of soft biological tissues and hydrogels at the cell-length scale in view of supporting tissue engineering and pathophysiological investigations
A programmable culture platform for stimulation and in situ sensing of lung epithelial cells
No full textBroadly Accessible 3D In Vitro Skin Model as a Comprehensive Platform for Antibacterial Therapy Screening
No full textSkin infections are currently a worldwide emergency as antibiotic-resistant bacteria are spreading, leading to the ineffectiveness of most antibiotics and antibacterial strategies. Consequently, there is an urgency of developing and testing innovative antibacterial therapies. As traditional 2D cell culture and planktonic bacteria culture can be obsolete due to their incapability of resembling the complex infection environment, 3D in vitro skin models can be a powerful tool to test and validate therapies. In this article, a 3D in vitro epidermis–dermis skin model has been developed and biofabricated to be broadly available, reaching a balance between the simplicity and reproducibility of the model and its complexity in terms of wound, infection, and treatment response. The results are really promising, as the skin model developed a comprehensive physical barrier. To further investigate the skin model, controlled wounding, infection, and antibiotic treatments were performed. The results were remarkable: Not only was the unwounded epidermal barrier able to partially stop the bacterial proliferation, but the entire system reacted to both wound and infection in a complex and complete way. Extracellular matrix deposition and remodeling, inflammatory response, antimicrobial peptide production, and change in cellular behaviors, from epithelial to mesenchymal and from fibroblasts to myofibroblasts, were witnessed, with different extents depending on the bacterial strain. In addition, the inflammatory response to the antibiotic administration was opposite for the two bacterial infections, probably revealing the release of inflammatory endotoxins during Escherichia coli death. In conclusion, the presented 3D in vitro skin model has all the characteristics to be a future landmark as a platform for antibacterial strategy therapy testing
