Validation of a Novel Microscale Mold Patterning Protocol Based on Gelatin Methacrylate Photopolymerizable Hydrogels

Author(s):  
Paola Occhetta ◽  
Nasser Sadr ◽  
Francesco Piraino ◽  
Alberto Redaelli ◽  
Matteo Moretti ◽  
...  

Native tissues are composed of functional three-dimensional (3D) units on the scale of 100–1000μm. The 3D architecture of these repeating units underlies the coordination of multicellular processes such as proliferation, differentiation, migration and apoptosis[1]. The requirement for 3D biomimetic matrices to mimic in vitro the ECM microarchitecture found in vivo becomes relevant in complex and vascularized tissue engineered models[2]. Among others, photopolymerizable hydrogels offer tunable geometrical features similar to the macromolecular-based components of soft ECM [3], can be crosslinked either in vivo or in vitro in the presence of a photoinitiator agent (PI) using visible or ultraviolet (UV) light irradiation, and have shown good compatibility with several protocols for cell embedding at different size-scales. In the present study, a new protocol to obtain cell-laden hydrogel micropatterns with highly controlled geometrical features is presented, based on the combination of polydimethylsiloxane (PDMS) replica molding and UV photopolimerization of methacrylate gelatin (GelMA).

2021 ◽  
Author(s):  
Rachel M McLaughlin ◽  
Amanda Laguna ◽  
Ilayda Top ◽  
Christien Hernadez ◽  
Liane L Livi ◽  
...  

Stroke is a devastating neurological disorder and a leading cause of death and long-term disability. Despite many decades of research, there are still very few therapeutic options for patients suffering from stroke or its consequences. This is partially due to the limitations of current research models, including traditional in vitro models which lack the three-dimensional (3D) architecture and cellular make-up of the in vivo brain. 3D spheroids derived from primary postnatal rat cortex provide an in vivo-relevant model containing a similar cellular composition to the native cortex and a cell-synthesized extracellular matrix. These spheroids are cost-effective, highly reproducible, and can be produced in a high-throughput manner, making this model an ideal candidate for screening potential therapeutics. To study the cellular and molecular mechanisms of stroke in this model, spheroids were deprived of glucose, oxygen, or both oxygen and glucose for 24 hours. Both oxygen and oxygen-glucose deprived spheroids demonstrated many of the hallmarks of stroke, including a decrease in metabolism, an increase in neural dysfunction, and an increase in reactive astrocytes. Pretreatment of spheroids with the antioxidant agent N-acetylcysteine (NAC) mitigated the decrease in ATP seen after 24 hours of oxygen-glucose deprivation. Together, these results show the utility of our 3D cortical spheroid model for studying ischemic injury and its potential for screening stroke therapeutics.


2021 ◽  
Vol 8 ◽  
pp. 204993612199854
Author(s):  
Chun Shing Kwok ◽  
Mustafa Dashti ◽  
Jacopo Tafuro ◽  
Mojtaba Nasiri ◽  
Elena-Andra Muntean ◽  
...  

Background: Cleaning is a major control component for outbreaks of infection. However, for the SARS-CoV-2 pandemic, there is limited specific guidance regarding the proper disinfection methods that should be used. Methods: We conducted a systematic review of the literature on cleaning, disinfection or decontamination methods in the prevention of SARS-CoV-2. Results: A total of 27 studies were included, reporting a variety of methods with which the effectiveness of interventions were assessed. Virus was inoculated onto different types of material including masks, nasopharyngeal swabs, serum, laboratory plates and simulated saliva, tears or nasal fluid and then interventions were applied in an attempt to eliminate the virus including chemical, ultraviolet (UV) light irradiation, and heat and humidity. At body temperature (37°C) there is evidence that the virus will not be detectable after 2 days but this can be reduced to non-detection at 30 min at 56°C, 15 min at 65°C and 2 min at 98°C. Different experimental methods testing UV light have shown that it can inactivate the virus. Light of 254–365 nm has been used, including simulated sunlight. Many chemical agents including bleach, hand sanitiser, hand wash, soap, ethanol, isopropanol, guandinium thiocynate/t-octylphenoxypolyethoxyethanol, formaldehyde, povidone-iodine, 0.05% chlorhexidine, 0.1% benzalkonium chloride, acidic electrolysed water, Clyraguard copper iodine complex and hydrogen peroxide vapour have been shown to disinfect SARS-CoV-2. Conclusions: Heating, UV light irradiation and chemicals can be used to inactivate SARS-CoV-2 but there is insufficient evidence to support one measure over others in clinical practice.


2016 ◽  
Vol 674 ◽  
pp. 121-126 ◽  
Author(s):  
Inga Narkevica ◽  
Aigars Reinis ◽  
Lauma Bugovecka ◽  
Ingus Skadins ◽  
Errj Sansonetti ◽  
...  

Biomaterials used in bone repair must satisfy certain criteria in order to perform without undesirable immunological response. They must be biocompatible and should inhibit bacteria adhesion on the surface, that could led to strong inflammatory process and implant failure. Our study reveals a synergistic effect on bioactivity and bacteriostasis effect of the TiO2 ceramics with different surface properties and provides insight into the design of better biomedical implant surfaces. The results show that UV light irradiation has great impact on hidrophilicity of TiO2 ceramics, but little effect on the sample bacteriostatic effect and bioactivity. TiO2 ceramic samples showed no or very low bacterial adhesion. Nevertheless, in vitro bioactivity showed TiO2 ceramic that was thermally treated at lower temperature. Thus for bone repair it’s suggested to use TiO2 ceramic sintered at lower temperature in order to provide bioactivity with bacterostatic effect and use UV-light irradiation to improve hidrophilicity.


RSC Advances ◽  
2016 ◽  
Vol 6 (38) ◽  
pp. 31831-31839 ◽  
Author(s):  
Ilayaperumal Pradeep ◽  
Balagurusamy Balajothi ◽  
Sankaralingam Arunachalam ◽  
Rajakumar Dhivya ◽  
Annadurai Vinothkanna ◽  
...  

UV light irradiation visible responses of polymer ruthenium complexes.


Author(s):  
D. Reis ◽  
B. Vian ◽  
J. C. Roland

Wall morphogenesis in higher plants is a problem still open to controversy. Until now the possibility of a transmembrane control and the involvement of microtubules were mostly envisaged. Self-assembly processes have been observed in the case of walls of Chlamydomonas and bacteria. Spontaneous gelling interactions between xanthan and galactomannan from Ceratonia have been analyzed very recently. The present work provides indications that some processes of spontaneous aggregation could occur in higher plants during the formation and expansion of cell wall.Observations were performed on hypocotyl of mung bean (Phaseolus aureus) for which growth characteristics and wall composition have been previously defined.In situ, the walls of actively growing cells (primary walls) show an ordered three-dimensional organization (fig. 1). The wall is typically polylamellate with multifibrillar layers alternately transverse and longitudinal. Between these layers intermediate strata exist in which the orientation of microfibrils progressively rotates. Thus a progressive change in the morphogenetic activity occurs.


2018 ◽  
Vol 18 (4) ◽  
pp. 246-255 ◽  
Author(s):  
Lara Termini ◽  
Enrique Boccardo

In vitro culture of primary or established cell lines is one of the leading techniques in many areas of basic biological research. The use of pure or highly enriched cultures of specific cell types obtained from different tissues and genetics backgrounds has greatly contributed to our current understanding of normal and pathological cellular processes. Cells in culture are easily propagated generating an almost endless source of material for experimentation. Besides, they can be manipulated to achieve gene silencing, gene overexpression and genome editing turning possible the dissection of specific gene functions and signaling pathways. However, monolayer and suspension cultures of cells do not reproduce the cell type diversity, cell-cell contacts, cell-matrix interactions and differentiation pathways typical of the three-dimensional environment of tissues and organs from where they were originated. Therefore, different experimental animal models have been developed and applied to address these and other complex issues in vivo. However, these systems are costly and time consuming. Most importantly the use of animals in scientific research poses moral and ethical concerns facing a steadily increasing opposition from different sectors of the society. Therefore, there is an urgent need for the development of alternative in vitro experimental models that accurately reproduce the events observed in vivo to reduce the use of animals. Organotypic cultures combine the flexibility of traditional culture systems with the possibility of culturing different cell types in a 3D environment that reproduces both the structure and the physiology of the parental organ. Here we present a summarized description of the use of epithelial organotypic for the study of skin physiology, human papillomavirus biology and associated tumorigenesis.


Cancers ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 930
Author(s):  
Donatella Delle Cave ◽  
Riccardo Rizzo ◽  
Bruno Sainz ◽  
Giuseppe Gigli ◽  
Loretta L. del Mercato ◽  
...  

Pancreatic cancer, the fourth most common cancer worldwide, shows a highly unsuccessful therapeutic response. In the last 10 years, neither important advancements nor new therapeutic strategies have significantly impacted patient survival, highlighting the need to pursue new avenues for drug development discovery and design. Advanced cellular models, resembling as much as possible the original in vivo tumor environment, may be more successful in predicting the efficacy of future anti-cancer candidates in clinical trials. In this review, we discuss novel bioengineered platforms for anticancer drug discovery in pancreatic cancer, from traditional two-dimensional models to innovative three-dimensional ones.


1993 ◽  
Vol 21 (2) ◽  
pp. 191-195 ◽  
Author(s):  
Knut-Jan Andersen ◽  
Erik Ilsø Christensen ◽  
Hogne Vik

The tissue culture of multicellular spheroids from the renal epithelial cell line LLC-PK1 (proximal tubule) is described. This represents a biological system of intermediate complexity between renal tissue in vivo and simple monolayer cultures. The multicellular structures, which show many similarities to kidney tubules in vivo, including a vectorial water transport, should prove useful for studying the potential nephrotoxicity of drugs and chemicals in vitro. In addition, the propagation of renal epithelial cells as multicellular spheroids in serum-free culture may provide information on the release of specific biological parameters, which may be suppressed or masked in serum-supplemented media.


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