Pub Date : 2022-10-14eCollection Date: 2022-12-06DOI: 10.1098/rsfs.2022.0032
Steffen Geisel, Eleonora Secchi, Jan Vermant
Bacterial biofilms are communities living in a matrix consisting of self-produced, hydrated extracellular polymeric substances. Most microorganisms adopt the biofilm lifestyle since it protects by conferring resistance to antibiotics and physico-chemical stress factors. Consequently, mechanical removal is often necessary but rendered difficult by the biofilm's complex, viscoelastic response, and adhesive properties. Overall, the mechanical behaviour of biofilms also plays a role in the spreading, dispersal and subsequent colonization of new surfaces. Therefore, the characterization of the mechanical properties of biofilms plays a crucial role in controlling and combating biofilms in industrial and medical environments. We performed in situ shear rheological measurements of Bacillus subtilis biofilms grown between the plates of a rotational rheometer under well-controlled conditions relevant to many biofilm habitats. We investigated how the mechanical history preceding rheological measurements influenced biofilm mechanics and compared these results to the techniques commonly used in the literature. We also compare our results to measurements using interfacial rheology on bacterial pellicles formed at the air-water interface. This work aims to help understand how different growth and measurement conditions contribute to the large variability of mechanical properties reported in the literature and provide a new tool for the rigorous characterization of matrix components and biofilms.
{"title":"Experimental challenges in determining the rheological properties of bacterial biofilms.","authors":"Steffen Geisel, Eleonora Secchi, Jan Vermant","doi":"10.1098/rsfs.2022.0032","DOIUrl":"10.1098/rsfs.2022.0032","url":null,"abstract":"<p><p>Bacterial biofilms are communities living in a matrix consisting of self-produced, hydrated extracellular polymeric substances. Most microorganisms adopt the biofilm lifestyle since it protects by conferring resistance to antibiotics and physico-chemical stress factors. Consequently, mechanical removal is often necessary but rendered difficult by the biofilm's complex, viscoelastic response, and adhesive properties. Overall, the mechanical behaviour of biofilms also plays a role in the spreading, dispersal and subsequent colonization of new surfaces. Therefore, the characterization of the mechanical properties of biofilms plays a crucial role in controlling and combating biofilms in industrial and medical environments. We performed <i>in situ</i> shear rheological measurements of <i>Bacillus subtilis</i> biofilms grown between the plates of a rotational rheometer under well-controlled conditions relevant to many biofilm habitats. We investigated how the mechanical history preceding rheological measurements influenced biofilm mechanics and compared these results to the techniques commonly used in the literature. We also compare our results to measurements using interfacial rheology on bacterial pellicles formed at the air-water interface. This work aims to help understand how different growth and measurement conditions contribute to the large variability of mechanical properties reported in the literature and provide a new tool for the rigorous characterization of matrix components and biofilms.</p>","PeriodicalId":13795,"journal":{"name":"Interface Focus","volume":null,"pages":null},"PeriodicalIF":3.6,"publicationDate":"2022-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9560794/pdf/rsfs.2022.0032.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"40665459","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Mucus is a viscoelastic aqueous fluid that participates in the protective barrier of many mammals' epithelia. In the airways, together with cilia beating, mucus rheological properties are crucial for lung mucociliary function, and, when impaired, potentially participate in the onset and progression of chronic obstructive pulmonary disease (COPD). Samples of human mucus collected in vivo are inherently contaminated and are thus poorly characterized. Human bronchial epithelium (HBE) cultures, differentiated from primary cells at an air-liquid interface, are highly reliable models to assess non-contaminated mucus. In this paper, the viscoelastic properties of HBE mucus derived from healthy subjects, patients with COPD and from smokers are measured. Hallmarks of shear-thinning and elasticity are obtained at the macroscale, whereas at the microscale mucus appears as a heterogeneous medium showing an almost Newtonian behaviour in some extended regions and an elastic behaviour close to boundaries. In addition, we developed an original method to probe mucus adhesion at the microscopic scale using optical tweezers. The measured adhesion forces and the comparison with mucus-simulants rheology as well as mucus imaging collectively support a structure composed of a network of elastic adhesive filaments with a large mesh size, embedded in a very soft gel.
{"title":"Mucus from human bronchial epithelial cultures: rheology and adhesion across length scales.","authors":"Myriam Jory, Dario Donnarumma, Christophe Blanc, Karim Bellouma, Aurélie Fort, Isabelle Vachier, Laura Casanellas, Arnaud Bourdin, Gladys Massiera","doi":"10.1098/rsfs.2022.0028","DOIUrl":"10.1098/rsfs.2022.0028","url":null,"abstract":"<p><p>Mucus is a viscoelastic aqueous fluid that participates in the protective barrier of many mammals' epithelia. In the airways, together with cilia beating, mucus rheological properties are crucial for lung mucociliary function, and, when impaired, potentially participate in the onset and progression of chronic obstructive pulmonary disease (COPD). Samples of human mucus collected <i>in vivo</i> are inherently contaminated and are thus poorly characterized. Human bronchial epithelium (HBE) cultures, differentiated from primary cells at an air-liquid interface, are highly reliable models to assess non-contaminated mucus. In this paper, the viscoelastic properties of HBE mucus derived from healthy subjects, patients with COPD and from smokers are measured. Hallmarks of shear-thinning and elasticity are obtained at the macroscale, whereas at the microscale mucus appears as a heterogeneous medium showing an almost Newtonian behaviour in some extended regions and an elastic behaviour close to boundaries. In addition, we developed an original method to probe mucus adhesion at the microscopic scale using optical tweezers. The measured adhesion forces and the comparison with mucus-simulants rheology as well as mucus imaging collectively support a structure composed of a network of elastic adhesive filaments with a large mesh size, embedded in a very soft gel.</p>","PeriodicalId":13795,"journal":{"name":"Interface Focus","volume":null,"pages":null},"PeriodicalIF":3.6,"publicationDate":"2022-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9560788/pdf/rsfs.2022.0028.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"40665461","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Recent years have witnessed unprecedented growth in interdisciplinary engagement and collaboration of physical and life sciences, to which the very existence of the Royal Society Journal ‘Interface Focus’ testifies. The subject of rheology itself brings together physics, chemistry, chemical engineering, mathematics and computing. In the biological context, the interdisciplinarity becomes even richer. Cell biology in plants, animals and prokaryotes is usually described in terms of components, biochemical networks and signalling. Yet local flows, and deformations of the entire cell as well as its individual parts [1,2], are essential to function. Questions on such mechanical properties and phenomena are rarely addressed. At the tissue biology level, there are new challenges especially in the highly nonlinear range of deformations [3,4], coupling to smaller structures, and pathologies. Vascular biology (e.g. haematology) is clearly a field where rheology is vital [5], but other key rheological control problems emerge in digestive [6] and reproductive biology [7]. Other biological flows contain rheologically induced structural or phase transitions, and the understanding of how biological fluids and soft solids flow and deform is a key scientific area within this collaboration of physical and life sciences (blood [8], the cytosol, silk protein solutions [9], saliva, mucus [10], synovial fluid, biofilms [11–13], tissue buckling [14], bacterial rheotaxis [15] and E. coli bacteria swimming in media with liquid crystalline order [16] are just some examples [17]). This theme issue on ‘Complex rheology in biological systems’ brings together biorheological work across distinct disciplines in the physics and life sciences. Below,we summarize these contributions and extract common ideas andmethodologies. We hope this will promote their adoption across the field, and thereby accelerate the resolution of outstanding and unresolved problems in biorheology. Beyond that, this theme issue aims to raise awareness of new research questions that have not yet been fully formulated in some of the sub-fields, yet are key to awider understanding. As is generally true in the ‘physics of livingmatter’movement, the biological examples point to new physics and chemistry that is not evident in non-biological systems.
{"title":"Editorial: theme issue on complex rheology in biological systems","authors":"C. Schaefer, G. McKinley, T. McLeish","doi":"10.1098/rsfs.2022.0058","DOIUrl":"https://doi.org/10.1098/rsfs.2022.0058","url":null,"abstract":"Recent years have witnessed unprecedented growth in interdisciplinary engagement and collaboration of physical and life sciences, to which the very existence of the Royal Society Journal ‘Interface Focus’ testifies. The subject of rheology itself brings together physics, chemistry, chemical engineering, mathematics and computing. In the biological context, the interdisciplinarity becomes even richer. Cell biology in plants, animals and prokaryotes is usually described in terms of components, biochemical networks and signalling. Yet local flows, and deformations of the entire cell as well as its individual parts [1,2], are essential to function. Questions on such mechanical properties and phenomena are rarely addressed. At the tissue biology level, there are new challenges especially in the highly nonlinear range of deformations [3,4], coupling to smaller structures, and pathologies. Vascular biology (e.g. haematology) is clearly a field where rheology is vital [5], but other key rheological control problems emerge in digestive [6] and reproductive biology [7]. Other biological flows contain rheologically induced structural or phase transitions, and the understanding of how biological fluids and soft solids flow and deform is a key scientific area within this collaboration of physical and life sciences (blood [8], the cytosol, silk protein solutions [9], saliva, mucus [10], synovial fluid, biofilms [11–13], tissue buckling [14], bacterial rheotaxis [15] and E. coli bacteria swimming in media with liquid crystalline order [16] are just some examples [17]). This theme issue on ‘Complex rheology in biological systems’ brings together biorheological work across distinct disciplines in the physics and life sciences. Below,we summarize these contributions and extract common ideas andmethodologies. We hope this will promote their adoption across the field, and thereby accelerate the resolution of outstanding and unresolved problems in biorheology. Beyond that, this theme issue aims to raise awareness of new research questions that have not yet been fully formulated in some of the sub-fields, yet are key to awider understanding. As is generally true in the ‘physics of livingmatter’movement, the biological examples point to new physics and chemistry that is not evident in non-biological systems.","PeriodicalId":13795,"journal":{"name":"Interface Focus","volume":null,"pages":null},"PeriodicalIF":4.4,"publicationDate":"2022-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46397082","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-10-14eCollection Date: 2022-12-06DOI: 10.1098/rsfs.2022.0035
Samuel G V Charlton, Dorothee L Kurz, Steffen Geisel, Joaquin Jimenez-Martinez, Eleonora Secchi
Biofilms are biological viscoelastic gels composed of bacterial cells embedded in a self-secreted polymeric extracellular matrix (ECM). In environmental settings, such as in the rhizosphere and phyllosphere, biofilm colonization occurs at the solid-air interface. The biofilms' ability to colonize and expand over these surfaces depends on the formation of osmotic gradients and ECM viscoelastic properties. In this work, we study the influence of biofilm ECM components on its viscoelasticity and expansion, using the model organism Bacillus subtilis and deletion mutants of its three major ECM components, TasA, EPS and BslA. Using a multi-scale approach, we quantified macro-scale viscoelasticity and expansion dynamics. Furthermore, we used a microsphere assay to visualize the micro-scale expansion patterns. We find that the viscoelastic phase angle is likely the best viscoelastic parameter correlating to biofilm expansion dynamics. Moreover, we quantify the sensitivity of the biofilm to changes in substrate water potential as a function of ECM composition. Finally, we find that the deletion of ECM components significantly increases the coherence of micro-scale colony expansion patterns. These results demonstrate the influence of ECM viscoelasticity and substrate water potential on the expansion of biofilm colonies on wet surfaces at the air-solid interface, commonly found in natural environments.
{"title":"The role of biofilm matrix composition in controlling colony expansion and morphology.","authors":"Samuel G V Charlton, Dorothee L Kurz, Steffen Geisel, Joaquin Jimenez-Martinez, Eleonora Secchi","doi":"10.1098/rsfs.2022.0035","DOIUrl":"10.1098/rsfs.2022.0035","url":null,"abstract":"<p><p>Biofilms are biological viscoelastic gels composed of bacterial cells embedded in a self-secreted polymeric extracellular matrix (ECM). In environmental settings, such as in the rhizosphere and phyllosphere, biofilm colonization occurs at the solid-air interface. The biofilms' ability to colonize and expand over these surfaces depends on the formation of osmotic gradients and ECM viscoelastic properties. In this work, we study the influence of biofilm ECM components on its viscoelasticity and expansion, using the model organism <i>Bacillus subtilis</i> and deletion mutants of its three major ECM components, TasA, EPS and BslA. Using a multi-scale approach, we quantified macro-scale viscoelasticity and expansion dynamics. Furthermore, we used a microsphere assay to visualize the micro-scale expansion patterns. We find that the viscoelastic phase angle <math><mi>Φ</mi></math> is likely the best viscoelastic parameter correlating to biofilm expansion dynamics. Moreover, we quantify the sensitivity of the biofilm to changes in substrate water potential as a function of ECM composition. Finally, we find that the deletion of ECM components significantly increases the coherence of micro-scale colony expansion patterns. These results demonstrate the influence of ECM viscoelasticity and substrate water potential on the expansion of biofilm colonies on wet surfaces at the air-solid interface, commonly found in natural environments.</p>","PeriodicalId":13795,"journal":{"name":"Interface Focus","volume":null,"pages":null},"PeriodicalIF":3.6,"publicationDate":"2022-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9560791/pdf/rsfs.2022.0035.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"40665402","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-10-14eCollection Date: 2022-12-06DOI: 10.1098/rsfs.2022.0036
Suhyang Lee, Khawaja Muhammad Imran Bashir, Dong Hee Jung, Santanu Kumar Basu, Gayeon Seo, Man-Gi Cho, Andreas Wierschem
The rheological properties of cells have vital functional implications. Depending, for instance, on the life cycle, cells show large cell-to-cell variations making it cumbersome to quantify average viscoelastic properties of cells by single-cell techniques. Microfluidic devices, typically working in the nonlinear viscoelastic range, allow fast analysis of single-cell deformation. Averaging over a large number of cells can also be achieved by studying them in a monolayer between rheometer discs. This technique allows applying well-established rheological standard procedures to cell rheology. It offers further advantages like studying cells in the linear viscoelastic range while quantifying cell vitality. Here, we study the applicability of the technique to rather adverse conditions, like for microtubule-active anti-cancer drugs and for a cell line with large size variation. We found a strong impact of the gap width and of normal forces on the moduli and obtained high vitality levels during the rheological study. To enable studying the impact of microtubule-active drugs on vital cells at concentrations several orders of magnitude beyond the half maximal effective concentration for cytotoxicity, we arrested the cell cycle with hydroxyurea. Irrespective of the high concentrations, we observed no clear impact of the microtubule-active drugs.
{"title":"Measuring the linear viscoelastic regime of MCF-7 cells with a monolayer rheometer in the presence of microtubule-active anti-cancer drugs at high concentrations.","authors":"Suhyang Lee, Khawaja Muhammad Imran Bashir, Dong Hee Jung, Santanu Kumar Basu, Gayeon Seo, Man-Gi Cho, Andreas Wierschem","doi":"10.1098/rsfs.2022.0036","DOIUrl":"10.1098/rsfs.2022.0036","url":null,"abstract":"<p><p>The rheological properties of cells have vital functional implications. Depending, for instance, on the life cycle, cells show large cell-to-cell variations making it cumbersome to quantify average viscoelastic properties of cells by single-cell techniques. Microfluidic devices, typically working in the nonlinear viscoelastic range, allow fast analysis of single-cell deformation. Averaging over a large number of cells can also be achieved by studying them in a monolayer between rheometer discs. This technique allows applying well-established rheological standard procedures to cell rheology. It offers further advantages like studying cells in the linear viscoelastic range while quantifying cell vitality. Here, we study the applicability of the technique to rather adverse conditions, like for microtubule-active anti-cancer drugs and for a cell line with large size variation. We found a strong impact of the gap width and of normal forces on the moduli and obtained high vitality levels during the rheological study. To enable studying the impact of microtubule-active drugs on vital cells at concentrations several orders of magnitude beyond the half maximal effective concentration for cytotoxicity, we arrested the cell cycle with hydroxyurea. Irrespective of the high concentrations, we observed no clear impact of the microtubule-active drugs.</p>","PeriodicalId":13795,"journal":{"name":"Interface Focus","volume":null,"pages":null},"PeriodicalIF":3.6,"publicationDate":"2022-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9560786/pdf/rsfs.2022.0036.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"40665455","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-10-14eCollection Date: 2022-12-06DOI: 10.1098/rsfs.2022.0038
Alexander Erlich, Jocelyn Étienne, Jonathan Fouchard, Tom Wyatt
Cells and tissues change shape both to carry out their function and during pathology. In most cases, these deformations are driven from within the systems themselves. This is permitted by a range of molecular actors, such as active crosslinkers and ion pumps, whose activity is biologically controlled in space and time. The resulting stresses are propagated within complex and dynamical architectures like networks or cell aggregates. From a mechanical point of view, these effects can be seen as the generation of prestress or prestrain, resulting from either a contractile or growth activity. In this review, we present this concept of prestress and the theoretical tools available to conceptualize the statics and dynamics of living systems. We then describe a range of phenomena where prestress controls shape changes in biopolymer networks (especially the actomyosin cytoskeleton and fibrous tissues) and cellularized tissues. Despite the diversity of scale and organization, we demonstrate that these phenomena stem from a limited number of spatial distributions of prestress, which can be categorized as heterogeneous, anisotropic or differential. We suggest that in addition to growth and contraction, a third type of prestress-topological prestress-can result from active processes altering the microstructure of tissue.
{"title":"How dynamic prestress governs the shape of living systems, from the subcellular to tissue scale.","authors":"Alexander Erlich, Jocelyn Étienne, Jonathan Fouchard, Tom Wyatt","doi":"10.1098/rsfs.2022.0038","DOIUrl":"10.1098/rsfs.2022.0038","url":null,"abstract":"<p><p>Cells and tissues change shape both to carry out their function and during pathology. In most cases, these deformations are driven from within the systems themselves. This is permitted by a range of molecular actors, such as active crosslinkers and ion pumps, whose activity is biologically controlled in space and time. The resulting stresses are propagated within complex and dynamical architectures like networks or cell aggregates. From a mechanical point of view, these effects can be seen as the generation of prestress or prestrain, resulting from either a contractile or growth activity. In this review, we present this concept of prestress and the theoretical tools available to conceptualize the statics and dynamics of living systems. We then describe a range of phenomena where prestress controls shape changes in biopolymer networks (especially the actomyosin cytoskeleton and fibrous tissues) and cellularized tissues. Despite the diversity of scale and organization, we demonstrate that these phenomena stem from a limited number of spatial distributions of prestress, which can be categorized as heterogeneous, anisotropic or differential. We suggest that in addition to growth and contraction, a third type of prestress-topological prestress-can result from active processes altering the microstructure of tissue.</p>","PeriodicalId":13795,"journal":{"name":"Interface Focus","volume":null,"pages":null},"PeriodicalIF":4.4,"publicationDate":"2022-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9560792/pdf/rsfs.2022.0038.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"40665458","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
David Hardman, Manh-Louis Nguyen, Stéphanie Descroix, Miguel O Bernabeu
Muscle-on-chip devices aim to recapitulate the physiological characteristics of in vivo muscle tissue and so maintaining levels of oxygen transported to cells is essential for cell survival and for providing the normoxic conditions experienced in vivo. We use finite-element method numerical modelling to describe oxygen transport and reaction in a proposed three-dimensional muscle-on-chip bioreactor with embedded channels for muscle cells and growth medium. We determine the feasibility of ensuring adequate oxygen for muscle cell survival in a device sealed from external oxygen sources and perfused via medium channels. We investigate the effects of varying elements of the bioreactor design on oxygen transport to optimize muscle tissue yield and maintain normoxic conditions. Successful co-culturing of muscle cells with motor neurons can boost muscle tissue function and so we estimate the maximum density of seeded neurons supported by oxygen concentrations within the bioreactor. We show that an enclosed bioreactor can provide sufficient oxygen for muscle cell survival and growth. We define a more efficient arrangement of muscle and perfusion chambers that can sustain a predicted 50% increase in maximum muscle volume per perfusion vessel. A study of simulated bioreactors provides functions for predicting bioreactor designs with normoxic conditions for any size of perfusion vessel, muscle chamber and distance between chambers.
{"title":"Mathematical modelling of oxygen transport in a muscle-on-chip device.","authors":"David Hardman, Manh-Louis Nguyen, Stéphanie Descroix, Miguel O Bernabeu","doi":"10.1098/rsfs.2022.0020","DOIUrl":"https://doi.org/10.1098/rsfs.2022.0020","url":null,"abstract":"<p><p>Muscle-on-chip devices aim to recapitulate the physiological characteristics of <i>in vivo</i> muscle tissue and so maintaining levels of oxygen transported to cells is essential for cell survival and for providing the normoxic conditions experienced <i>in vivo</i>. We use finite-element method numerical modelling to describe oxygen transport and reaction in a proposed three-dimensional muscle-on-chip bioreactor with embedded channels for muscle cells and growth medium. We determine the feasibility of ensuring adequate oxygen for muscle cell survival in a device sealed from external oxygen sources and perfused via medium channels. We investigate the effects of varying elements of the bioreactor design on oxygen transport to optimize muscle tissue yield and maintain normoxic conditions. Successful co-culturing of muscle cells with motor neurons can boost muscle tissue function and so we estimate the maximum density of seeded neurons supported by oxygen concentrations within the bioreactor. We show that an enclosed bioreactor can provide sufficient oxygen for muscle cell survival and growth. We define a more efficient arrangement of muscle and perfusion chambers that can sustain a predicted 50% increase in maximum muscle volume per perfusion vessel. A study of simulated bioreactors provides functions for predicting bioreactor designs with normoxic conditions for any size of perfusion vessel, muscle chamber and distance between chambers.</p>","PeriodicalId":13795,"journal":{"name":"Interface Focus","volume":null,"pages":null},"PeriodicalIF":4.4,"publicationDate":"2022-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9372644/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9152064","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Irfan Khan, Marium Naz Siddiqui, Fatima Jameel, Rida-E-Maria Qazi, Asmat Salim, Shazmeen Aslam, Midhat Batool Zaidi
Hypoxic wounds are tough to heal and are associated with chronicity, causing major healthcare burden. Available treatment options offer only limited success for accelerated and scarless healing. Traditional skin substitutes are widely used to improve wound healing, however, they lack proper vascularization. Mesenchymal stem cells (MSCs) offer improved wound healing; however, their poor retention, survival and adherence at the wound site negatively affect their therapeutic potential. The aim of this study is to enhance skin regeneration in a rat model of full-thickness dermal wound by transplanting genetically modified MSCs seeded on a three-dimensional collagen scaffold. Rat bone marrow MSCs were efficiently incorporated in the acellular collagen scaffold. Skin tissues with transplanted subcutaneous scaffolds were histologically analysed, while angiogenesis was assessed both at gene and protein levels. Our findings demonstrated that three-dimensional collagen scaffolds play a potential role in the survival and adherence of stem cells at the wound site, while modification of MSCs with jagged one gene provides a conducive environment for wound regeneration with improved proliferation, reduced inflammation and enhanced vasculogenesis. The results of this study represent an advanced targeted approach having the potential to be translated in clinical settings for targeted personalized therapy.
{"title":"Potential of stem cell seeded three-dimensional scaffold for regeneration of full-thickness skin wounds.","authors":"Irfan Khan, Marium Naz Siddiqui, Fatima Jameel, Rida-E-Maria Qazi, Asmat Salim, Shazmeen Aslam, Midhat Batool Zaidi","doi":"10.1098/rsfs.2022.0017","DOIUrl":"https://doi.org/10.1098/rsfs.2022.0017","url":null,"abstract":"<p><p>Hypoxic wounds are tough to heal and are associated with chronicity, causing major healthcare burden. Available treatment options offer only limited success for accelerated and scarless healing. Traditional skin substitutes are widely used to improve wound healing, however, they lack proper vascularization. Mesenchymal stem cells (MSCs) offer improved wound healing; however, their poor retention, survival and adherence at the wound site negatively affect their therapeutic potential. The aim of this study is to enhance skin regeneration in a rat model of full-thickness dermal wound by transplanting genetically modified MSCs seeded on a three-dimensional collagen scaffold. Rat bone marrow MSCs were efficiently incorporated in the acellular collagen scaffold. Skin tissues with transplanted subcutaneous scaffolds were histologically analysed, while angiogenesis was assessed both at gene and protein levels. Our findings demonstrated that three-dimensional collagen scaffolds play a potential role in the survival and adherence of stem cells at the wound site, while modification of MSCs with jagged one gene provides a conducive environment for wound regeneration with improved proliferation, reduced inflammation and enhanced vasculogenesis. The results of this study represent an advanced targeted approach having the potential to be translated in clinical settings for targeted personalized therapy.</p>","PeriodicalId":13795,"journal":{"name":"Interface Focus","volume":null,"pages":null},"PeriodicalIF":4.4,"publicationDate":"2022-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9372646/pdf/rsfs.2022.0017.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9981139","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jonathan Temple, Eirini Velliou, Mona Shehata, Raphaël Lévy
From growing cells in spheroids to arranging them on complex engineered scaffolds, three-dimensional cell culture protocols are rapidly expanding and diversifying. While these systems may often improve the physiological relevance of cell culture models, they come with technical challenges, as many of the analytical methods used to characterize traditional two-dimensional (2D) cells must be modified or replaced to be effective. Here we review the advantages and limitations of quantification methods based either on biochemical measurements or microscopy imaging. We focus on the most basic of parameters that one may want to measure, the number of cells. Precise determination of this number is essential for many analytical techniques where measured quantities are only meaningful when normalized to the number of cells (e.g. cytochrome p450 enzyme activity). Thus, accurate measurement of cell number is often a prerequisite to allowing comparisons across different conditions (culturing conditions or drug and treatment screening) or between cells in different spatial states. We note that this issue is often neglected in the literature with little or no information given regarding how normalization was performed, we highlight the pitfalls and complications of quantification and call for more accurate reporting to improve reproducibility.
{"title":"Current strategies with implementation of three-dimensional cell culture: the challenge of quantification.","authors":"Jonathan Temple, Eirini Velliou, Mona Shehata, Raphaël Lévy","doi":"10.1098/rsfs.2022.0019","DOIUrl":"https://doi.org/10.1098/rsfs.2022.0019","url":null,"abstract":"<p><p>From growing cells in spheroids to arranging them on complex engineered scaffolds, three-dimensional cell culture protocols are rapidly expanding and diversifying. While these systems may often improve the physiological relevance of cell culture models, they come with technical challenges, as many of the analytical methods used to characterize traditional two-dimensional (2D) cells must be modified or replaced to be effective. Here we review the advantages and limitations of quantification methods based either on biochemical measurements or microscopy imaging. We focus on the most basic of parameters that one may want to measure, the number of cells. Precise determination of this number is essential for many analytical techniques where measured quantities are only meaningful when normalized to the number of cells (e.g. cytochrome p450 enzyme activity). Thus, accurate measurement of cell number is often a prerequisite to allowing comparisons across different conditions (culturing conditions or drug and treatment screening) or between cells in different spatial states. We note that this issue is often neglected in the literature with little or no information given regarding how normalization was performed, we highlight the pitfalls and complications of quantification and call for more accurate reporting to improve reproducibility.</p>","PeriodicalId":13795,"journal":{"name":"Interface Focus","volume":null,"pages":null},"PeriodicalIF":4.4,"publicationDate":"2022-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9372643/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9205780","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-08-12eCollection Date: 2022-10-06DOI: 10.1098/rsfs.2022.0040
Anushka Bhargava, Ana M Sandoval Castellanos, Sonali Shah, Ke Ning
The use of induced pluripotent stem cells (iPSCs) is a promising approach when used as models to study neurodegenerative disorders (NDDs) in vitro. iPSCs have been used in in vitro two-dimensional cultures; however, these two-dimensional cultures do not mimic the physiological three-dimensional cellular environment. The use of iPSCs-derived three-dimensional organoids has risen as a powerful alternative to using animal models to study NDDs. These iPSCs-derived three-dimensional organoids can resemble the complexity of the tissue of interest, making it an approachable, cost-effective technique, to study NDDs in an ethical manner. Furthermore, the use of iPSCs-derived organoids will be an important tool to develop new therapeutics and pharmaceutics to treat NDDs. Herein, we will highlight how iPSCs-derived two-dimensional cultures and three-dimensional organoids have been used to study NDDs, as well as the advantages and disadvantages of both techniques.
{"title":"An insight into the iPSCs-derived two-dimensional culture and three-dimensional organoid models for neurodegenerative disorders.","authors":"Anushka Bhargava, Ana M Sandoval Castellanos, Sonali Shah, Ke Ning","doi":"10.1098/rsfs.2022.0040","DOIUrl":"10.1098/rsfs.2022.0040","url":null,"abstract":"<p><p>The use of induced pluripotent stem cells (iPSCs) is a promising approach when used as models to study neurodegenerative disorders (NDDs) <i>in vitro</i>. iPSCs have been used in <i>in vitro</i> two-dimensional cultures; however, these two-dimensional cultures do not mimic the physiological three-dimensional cellular environment. The use of iPSCs-derived three-dimensional organoids has risen as a powerful alternative to using animal models to study NDDs. These iPSCs-derived three-dimensional organoids can resemble the complexity of the tissue of interest, making it an approachable, cost-effective technique, to study NDDs in an ethical manner. Furthermore, the use of iPSCs-derived organoids will be an important tool to develop new therapeutics and pharmaceutics to treat NDDs. Herein, we will highlight how iPSCs-derived two-dimensional cultures and three-dimensional organoids have been used to study NDDs, as well as the advantages and disadvantages of both techniques.</p>","PeriodicalId":13795,"journal":{"name":"Interface Focus","volume":null,"pages":null},"PeriodicalIF":3.6,"publicationDate":"2022-08-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9372641/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9152058","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}