Pub Date : 2021-06-10DOI: 10.1080/1539445X.2021.1906703
K. Binder, P. Virnau
ABSTRACT A tutorial introduction to the statistical mechanics of phase transitions and phase coexistence is presented, starting out from equilibrium systems and nonequilibrium steady-state situations in externally driven systems, such as unmixing of sheared binary fluid mixtures, the driven lattice gas model, and the onset of Rayleigh-Bénard convection. Then, some models for phase separation in models for active systems, where particles possess internal motility, are discussed, emphasizing what one can learn by extending analysis methods to study phase transitions in equilibrium systems by computer simulations to active systems. Specific examples will include colloid-polymer mixtures where the colloids are assumed to be active particles, and active Brownian particles. The extent to which concepts familiar from the study of equilibrium systems are still useful will be critically discussed.
{"title":"Phase transitions and phase coexistence: equilibrium systems versus externally driven or active systems - Some perspectives","authors":"K. Binder, P. Virnau","doi":"10.1080/1539445X.2021.1906703","DOIUrl":"https://doi.org/10.1080/1539445X.2021.1906703","url":null,"abstract":"ABSTRACT A tutorial introduction to the statistical mechanics of phase transitions and phase coexistence is presented, starting out from equilibrium systems and nonequilibrium steady-state situations in externally driven systems, such as unmixing of sheared binary fluid mixtures, the driven lattice gas model, and the onset of Rayleigh-Bénard convection. Then, some models for phase separation in models for active systems, where particles possess internal motility, are discussed, emphasizing what one can learn by extending analysis methods to study phase transitions in equilibrium systems by computer simulations to active systems. Specific examples will include colloid-polymer mixtures where the colloids are assumed to be active particles, and active Brownian particles. The extent to which concepts familiar from the study of equilibrium systems are still useful will be critically discussed.","PeriodicalId":22140,"journal":{"name":"Soft Materials","volume":"19 1","pages":"267 - 285"},"PeriodicalIF":1.2,"publicationDate":"2021-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/1539445X.2021.1906703","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43867413","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-06-04DOI: 10.1080/1539445X.2021.1933032
Veena Acharya, Aritri Ghosh, A. Chowdhury, P. Datta
ABSTRACT Tannic acid (TA) is a polyphenol with potential to crosslink biomacromolecules. Though, feasibility of TA crosslinking is known, the more toxic glutaraladehyde (GA) continue to be used extensively for developing novel chitosan-based scaffolds, hindering in vivo translation. Thus, a direct comparison between TA- and GA-crosslinked chitosan membranes with respect to physico-chemical, biocomptability and biofunctional properties is required. Role of TA to modulate epigenetic changes in cultured cells is also investigated. TA-crosslinked scaffolds differed from GA in contact angle and swelling by 20–25% while mechanical properties and degradation differed by 50%. Cell viability on TA-crosslinked scaffolds was ~1.4 times higher compared to GA-crosslinked samples, osteocalcin expression was two-fold higher and ROS and cox-2 expression was reduced by ~1.4 times (p < .01). TA crosslinking modulated epigenetic changes in cultured cells by evidencing global DNA hypomethylation. It is concluded that TA can provide a flexible scaffold with ability to modulate epigenetics and osteogeneticity.
{"title":"Tannic acid-crosslinked chitosan matrices enhance osteogenic differentiation and modulate epigenetic status of cultured cells over glutaraldehyde crosslinking","authors":"Veena Acharya, Aritri Ghosh, A. Chowdhury, P. Datta","doi":"10.1080/1539445X.2021.1933032","DOIUrl":"https://doi.org/10.1080/1539445X.2021.1933032","url":null,"abstract":"ABSTRACT Tannic acid (TA) is a polyphenol with potential to crosslink biomacromolecules. Though, feasibility of TA crosslinking is known, the more toxic glutaraladehyde (GA) continue to be used extensively for developing novel chitosan-based scaffolds, hindering in vivo translation. Thus, a direct comparison between TA- and GA-crosslinked chitosan membranes with respect to physico-chemical, biocomptability and biofunctional properties is required. Role of TA to modulate epigenetic changes in cultured cells is also investigated. TA-crosslinked scaffolds differed from GA in contact angle and swelling by 20–25% while mechanical properties and degradation differed by 50%. Cell viability on TA-crosslinked scaffolds was ~1.4 times higher compared to GA-crosslinked samples, osteocalcin expression was two-fold higher and ROS and cox-2 expression was reduced by ~1.4 times (p < .01). TA crosslinking modulated epigenetic changes in cultured cells by evidencing global DNA hypomethylation. It is concluded that TA can provide a flexible scaffold with ability to modulate epigenetics and osteogeneticity.","PeriodicalId":22140,"journal":{"name":"Soft Materials","volume":"20 1","pages":"149 - 160"},"PeriodicalIF":1.2,"publicationDate":"2021-06-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/1539445X.2021.1933032","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46556063","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-05-27DOI: 10.1080/1539445X.2021.1937223
Sudipta Pattanayak, Shradha Mishra, S. Puri
ABSTRACT We study the ordering kinetics of an assembly of active Brownian particles (ABPs) on a two-dimensional substrate. We use a coarse-grained equation for the composition order parameter ,where and denote space and time, respectively. The model is similar to the Cahn-Hilliard equation orModel B (MB) for a conserved order parameter with an additional activity term of strength . This model has been introduced by Wittkowski et al., Nature Comm. 5, 4351 (2014), and is termed Active Model B (AMB). We study domain growth kinetics and dynamical scaling of the correlation function for the AMB with critical and off-critical compositions. The quantity governs the asymptotic growth kinetics for the off-critical AMB, where denotes the average order parameter. For negative ,the domain growth law is the usual Lifshitz-Slyozov growth law with . For positive ,the growth law shows a crossover to a novel growth law . Further, the correlation function shows good dynamical scaling for the off-critical AMB but the scaling function has a dependency on and . We also study the effects of both additive and multiplicative noise on the AMB.
摘要研究了二维基底上活性布朗粒子(ABPs)的有序动力学。我们使用粗粒度方程来表示组合顺序参数，其中和分别表示空间和时间。该模型与Cahn-Hilliard方程或模型B (MB)相似，该模型具有一个守恒的阶参数和一个额外的强度活动项。该模型由Wittkowski等人在Nature Comm. 5,4351(2014)中提出，并被称为Active model B (AMB)。我们研究了具有临界和非临界成分的AMB的畴生长动力学和相关函数的动态标度。数量决定了非临界AMB的渐近生长动力学，其中表示平均序参量。当为负时，域生长律为通常的Lifshitz-Slyozov生长律。对于正的情况，增长律显示出与新增长律的交叉。此外，相关函数对非临界AMB表现出良好的动态标度，但标度函数依赖于和。我们还研究了加性和乘性噪声对AMB的影响。
{"title":"Domain Growth in the Active Model B: Critical and Off-critical Composition","authors":"Sudipta Pattanayak, Shradha Mishra, S. Puri","doi":"10.1080/1539445X.2021.1937223","DOIUrl":"https://doi.org/10.1080/1539445X.2021.1937223","url":null,"abstract":"ABSTRACT We study the ordering kinetics of an assembly of active Brownian particles (ABPs) on a two-dimensional substrate. We use a coarse-grained equation for the composition order parameter ,where and denote space and time, respectively. The model is similar to the Cahn-Hilliard equation orModel B (MB) for a conserved order parameter with an additional activity term of strength . This model has been introduced by Wittkowski et al., Nature Comm. 5, 4351 (2014), and is termed Active Model B (AMB). We study domain growth kinetics and dynamical scaling of the correlation function for the AMB with critical and off-critical compositions. The quantity governs the asymptotic growth kinetics for the off-critical AMB, where denotes the average order parameter. For negative ,the domain growth law is the usual Lifshitz-Slyozov growth law with . For positive ,the growth law shows a crossover to a novel growth law . Further, the correlation function shows good dynamical scaling for the off-critical AMB but the scaling function has a dependency on and . We also study the effects of both additive and multiplicative noise on the AMB.","PeriodicalId":22140,"journal":{"name":"Soft Materials","volume":"19 1","pages":"286 - 296"},"PeriodicalIF":1.2,"publicationDate":"2021-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/1539445X.2021.1937223","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47822363","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-05-21DOI: 10.1080/1539445X.2021.1926282
Lucy R. Hart, Saige M. Mitchell, P. A. McCallum, Rachel E. Daso, I. Banerjee
ABSTRACT Self-assembled supramolecular structures have gained attention due to their wide range of applications. In this work, we have created two novel drug delivery systems for targeting MCF-7 breast cancer cells using polyphenols derived from rosemary extract. The assemblies were synthesized by conjugating rosmarinic acid (RMA) and carnosic acid (CSA) with the peptide sequence H-A-I-L-L-I-T-K-G-I-F-K known for its ability to target MCF-7 breast cancer cells. The products were self-assembled into nanofibers or oblong shaped nanoassemblies. The mechanism of self-assembly was probed by COSMOS-RS computational studies. The assemblies were utilized to entrap the drug topotecan. Entrapment efficiency varied based on the morphology of the assemblies and concentration (42.3% for carnosic acid-peptide assemblies and 59.11% for rosmarinic acid-peptide assemblies). Furthermore, the RMA-peptide and CSA-peptide assemblies were found to be cytotoxic toward MCF-7 breast cancer cells, with relatively higher cytotoxicity observed for the topotecan entrapped CSA-peptide assemblies compared to topotecan entrapped RMA-peptide assemblies. Docking studies were conducted to examine binding interactions of the RMA-peptide and CSA-peptide conjugates with Src kinase receptor and estrogen receptor. Furthermore, CSA-peptide assemblies induced apoptosis while RMA-peptide assemblies induced necrosis. Our results indicate that such new biomimetic materials derived from naturally occurring polyphenols may be developed for dual targeting tumor cells.
{"title":"Self-assembled peptide-conjugated rosemary extract derivatives as drug delivery vehicles for targeting tumor cells","authors":"Lucy R. Hart, Saige M. Mitchell, P. A. McCallum, Rachel E. Daso, I. Banerjee","doi":"10.1080/1539445X.2021.1926282","DOIUrl":"https://doi.org/10.1080/1539445X.2021.1926282","url":null,"abstract":"ABSTRACT Self-assembled supramolecular structures have gained attention due to their wide range of applications. In this work, we have created two novel drug delivery systems for targeting MCF-7 breast cancer cells using polyphenols derived from rosemary extract. The assemblies were synthesized by conjugating rosmarinic acid (RMA) and carnosic acid (CSA) with the peptide sequence H-A-I-L-L-I-T-K-G-I-F-K known for its ability to target MCF-7 breast cancer cells. The products were self-assembled into nanofibers or oblong shaped nanoassemblies. The mechanism of self-assembly was probed by COSMOS-RS computational studies. The assemblies were utilized to entrap the drug topotecan. Entrapment efficiency varied based on the morphology of the assemblies and concentration (42.3% for carnosic acid-peptide assemblies and 59.11% for rosmarinic acid-peptide assemblies). Furthermore, the RMA-peptide and CSA-peptide assemblies were found to be cytotoxic toward MCF-7 breast cancer cells, with relatively higher cytotoxicity observed for the topotecan entrapped CSA-peptide assemblies compared to topotecan entrapped RMA-peptide assemblies. Docking studies were conducted to examine binding interactions of the RMA-peptide and CSA-peptide conjugates with Src kinase receptor and estrogen receptor. Furthermore, CSA-peptide assemblies induced apoptosis while RMA-peptide assemblies induced necrosis. Our results indicate that such new biomimetic materials derived from naturally occurring polyphenols may be developed for dual targeting tumor cells.","PeriodicalId":22140,"journal":{"name":"Soft Materials","volume":"20 1","pages":"109 - 128"},"PeriodicalIF":1.2,"publicationDate":"2021-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/1539445X.2021.1926282","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42542705","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-05-16DOI: 10.1080/1539445X.2021.1922443
R. S. Singh
ABSTRACT Amphiphiles are molecules that contain two discrete segments – a water-soluble hydrophilic part (head-group) and a water-insoluble hydrophobic part (tail). The structural variations possible with the head-group part are enormous and numerous amphiphiles have been designed in this way. On the other hand, the structural variations feasible for the hydrophobic tail part are rather limited. Saturated aliphatic hydrocarbon chains are predominantly found in most of the amphiphiles. Unsaturated aliphatic hydrocarbon chains (n-alkenyl or n-alkynyl chains) also serve as the hydrophobic tail part in many of the amphiphiles. Amphiphiles, wherein the hydrophobic tail part is made up of aromatic moieties (alone or in combination with aliphatic chains) are less frequently encountered compared to the other two types. Many of these aromatic amphiphiles, the focus of this review article, are known to form different types of assemblies including Langmuir and Langmuir-Blodgett (LB) films. In this review, we will provide an account of the different types of aromatic amphiphiles that have been reported and highlight their properties and applications at the air–water and air–solid interfaces.
{"title":"Langmuir and Langmuir–Blodgett films of aromatic amphiphiles","authors":"R. S. Singh","doi":"10.1080/1539445X.2021.1922443","DOIUrl":"https://doi.org/10.1080/1539445X.2021.1922443","url":null,"abstract":"ABSTRACT Amphiphiles are molecules that contain two discrete segments – a water-soluble hydrophilic part (head-group) and a water-insoluble hydrophobic part (tail). The structural variations possible with the head-group part are enormous and numerous amphiphiles have been designed in this way. On the other hand, the structural variations feasible for the hydrophobic tail part are rather limited. Saturated aliphatic hydrocarbon chains are predominantly found in most of the amphiphiles. Unsaturated aliphatic hydrocarbon chains (n-alkenyl or n-alkynyl chains) also serve as the hydrophobic tail part in many of the amphiphiles. Amphiphiles, wherein the hydrophobic tail part is made up of aromatic moieties (alone or in combination with aliphatic chains) are less frequently encountered compared to the other two types. Many of these aromatic amphiphiles, the focus of this review article, are known to form different types of assemblies including Langmuir and Langmuir-Blodgett (LB) films. In this review, we will provide an account of the different types of aromatic amphiphiles that have been reported and highlight their properties and applications at the air–water and air–solid interfaces.","PeriodicalId":22140,"journal":{"name":"Soft Materials","volume":"20 1","pages":"57 - 98"},"PeriodicalIF":1.2,"publicationDate":"2021-05-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/1539445X.2021.1922443","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43666369","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-05-15DOI: 10.1080/1539445X.2021.1926283
Yongxin Wang, Yanbing Kuai, G. Zhang, Hairui Zhang, J. Cong, Yunli Xu, Lizhi Yi, Min Liu, Yiman Liu
ABSTRACT Liquid metal micromotors have attracted mounting interest over the past decade, but their property of sticking to many surfaces has limited their controllable manipulation in three dimensions (3-D). In this work, we demonstrate a versatile and generic approach in manipulating Gallium-based liquid metal microfleas (LMMFs) on solid surfaces by strategically applied electric (E-) fields, in which the adhesion of LMMFs to solid surfaces is greatly reduced by tailoring the thickness of the oxide skins of the liquid metal. Numerical simulations and experimental demonstrations illustrate that the LMMFs can be readily driven to jump along prescribed trajectories with high localization accuracy (the order of ~10 microns). The prowess of the precision manipulation of LMMFs is further demonstrated in several practical applications, including the walking of LMMFs on the stairs, the micro-welding for cracked conducting wire, as well as the on-demand jumping of LMMFs on a “mini-piano.” Such a proposed approach provides a convenient, rather generic, E-field-based strategy for manipulation of LMMFs in non-liquid environments with a configurable, switchable, and programmable fashion, offering considerable potential for diverse practical applications in the near future.
{"title":"Electric-field-guided 3D manipulation of liquid metal microfleas","authors":"Yongxin Wang, Yanbing Kuai, G. Zhang, Hairui Zhang, J. Cong, Yunli Xu, Lizhi Yi, Min Liu, Yiman Liu","doi":"10.1080/1539445X.2021.1926283","DOIUrl":"https://doi.org/10.1080/1539445X.2021.1926283","url":null,"abstract":"ABSTRACT Liquid metal micromotors have attracted mounting interest over the past decade, but their property of sticking to many surfaces has limited their controllable manipulation in three dimensions (3-D). In this work, we demonstrate a versatile and generic approach in manipulating Gallium-based liquid metal microfleas (LMMFs) on solid surfaces by strategically applied electric (E-) fields, in which the adhesion of LMMFs to solid surfaces is greatly reduced by tailoring the thickness of the oxide skins of the liquid metal. Numerical simulations and experimental demonstrations illustrate that the LMMFs can be readily driven to jump along prescribed trajectories with high localization accuracy (the order of ~10 microns). The prowess of the precision manipulation of LMMFs is further demonstrated in several practical applications, including the walking of LMMFs on the stairs, the micro-welding for cracked conducting wire, as well as the on-demand jumping of LMMFs on a “mini-piano.” Such a proposed approach provides a convenient, rather generic, E-field-based strategy for manipulation of LMMFs in non-liquid environments with a configurable, switchable, and programmable fashion, offering considerable potential for diverse practical applications in the near future.","PeriodicalId":22140,"journal":{"name":"Soft Materials","volume":"20 1","pages":"129 - 136"},"PeriodicalIF":1.2,"publicationDate":"2021-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/1539445X.2021.1926283","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45606868","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
ABSTRACT In order to control complex motion behavior in organisms, most biological tissues have highly oriented structures and anisotropic mechanical properties, such as articular cartilage, muscle, skin and blood vessel. In this study, inspired by the directional structure and excellent mechanical properties of biological soft tissues, polyvinyl alcohol/carboxymethyl cellulose hydrogels with different contents of sodium alginate were prepared by combining freeze-thaw and prestretching methods. Compared with SEM images without pre-stretch hydrogels, there are obvious ordered pore structures in the pre-stretch samples along the tensile direction, and the network structure becomes denser. XRD and FTI R results indicate that the introduction of SA and CMC increases the number of internal hydrogen bond and forms new covalent bonds. The tensile strength of the hydrogel without annealing and stretching treatments is only 0.41MPa. After annealing and stretching treatments, the tensile strength of the hydrogel is increased to 0.93MPa. Furthermore, the creep deformation of hydrogel was reduced from 1.08 mm to 0.27 mm by annealing and stretching treatments. To sum up, these results suggested that PVA/SA/CMC composite hydrogels with oriented structure might have potential applications in soft tissue repair and other biomaterials.
{"title":"Preparation and characterization of polyvinyl alcohol/ sodium alginate/carboxymethyl cellulose composite hydrogels with oriented structure","authors":"Kai Chen, Tian-Xiang Zong, Qin Chen, Siyu Liu, Linmin Xu, Dekun Zhang","doi":"10.1080/1539445X.2021.1926281","DOIUrl":"https://doi.org/10.1080/1539445X.2021.1926281","url":null,"abstract":"ABSTRACT In order to control complex motion behavior in organisms, most biological tissues have highly oriented structures and anisotropic mechanical properties, such as articular cartilage, muscle, skin and blood vessel. In this study, inspired by the directional structure and excellent mechanical properties of biological soft tissues, polyvinyl alcohol/carboxymethyl cellulose hydrogels with different contents of sodium alginate were prepared by combining freeze-thaw and prestretching methods. Compared with SEM images without pre-stretch hydrogels, there are obvious ordered pore structures in the pre-stretch samples along the tensile direction, and the network structure becomes denser. XRD and FTI R results indicate that the introduction of SA and CMC increases the number of internal hydrogen bond and forms new covalent bonds. The tensile strength of the hydrogel without annealing and stretching treatments is only 0.41MPa. After annealing and stretching treatments, the tensile strength of the hydrogel is increased to 0.93MPa. Furthermore, the creep deformation of hydrogel was reduced from 1.08 mm to 0.27 mm by annealing and stretching treatments. To sum up, these results suggested that PVA/SA/CMC composite hydrogels with oriented structure might have potential applications in soft tissue repair and other biomaterials.","PeriodicalId":22140,"journal":{"name":"Soft Materials","volume":"20 1","pages":"99 - 108"},"PeriodicalIF":1.2,"publicationDate":"2021-05-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/1539445X.2021.1926281","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47982286","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-05-01DOI: 10.1080/1539445X.2021.1918719
P. Edwin, N. R. Rajagopalan, S. Bajpai
ABSTRACT Development of clinically amenable bio-implants with silk-fibroin (SF) necessitates characterization of cellular-traction generated between cells and the substrate. However, studies on the biomechanical response of cells on SF substrates are limited. In this study, we prepared SF hydrogels of varying compliance (SF30 and SF50) and varying surface-ligands (derivatized with poly-L-lysine (PLL) or Arg-Gly-Asp (RGD) peptide). Subsequently, NIH-3T3 fibroblast cells were grown on these substrates, and the morphological changes was examined. It was observed that the increase in SF stiffness from 0.7 kPa to 3.1 kPa decreased nucleus-to-cytoplasm area-ratio and increased asymmetricity along the major-axis of cells. Moreover, while functionalization of SF with RGD induced increase in cell-area and circularity, functionalization with PLL did not cause any change. Next, using traction-force-microscopy (TFM), we quantified 2D cell-traction for NIH-3T3 cells cultured on SF hydrogels. Cells plated on SF50 hydrogel exhibited significantly high traction stress as compared to SF30; change of functionalization did not show significant change. Also, protrusion traction stress was found to be greater than nuclear traction stress. Put together, our results suggest that surface-stiffness of SF-hydrogel, rather than nature of surface-ligand, regulates both cellular morphology and cellular traction stresses.
{"title":"Morphology and cellular-traction of fibroblasts on 2D silk-fibroin hydrogel substrates","authors":"P. Edwin, N. R. Rajagopalan, S. Bajpai","doi":"10.1080/1539445X.2021.1918719","DOIUrl":"https://doi.org/10.1080/1539445X.2021.1918719","url":null,"abstract":"ABSTRACT Development of clinically amenable bio-implants with silk-fibroin (SF) necessitates characterization of cellular-traction generated between cells and the substrate. However, studies on the biomechanical response of cells on SF substrates are limited. In this study, we prepared SF hydrogels of varying compliance (SF30 and SF50) and varying surface-ligands (derivatized with poly-L-lysine (PLL) or Arg-Gly-Asp (RGD) peptide). Subsequently, NIH-3T3 fibroblast cells were grown on these substrates, and the morphological changes was examined. It was observed that the increase in SF stiffness from 0.7 kPa to 3.1 kPa decreased nucleus-to-cytoplasm area-ratio and increased asymmetricity along the major-axis of cells. Moreover, while functionalization of SF with RGD induced increase in cell-area and circularity, functionalization with PLL did not cause any change. Next, using traction-force-microscopy (TFM), we quantified 2D cell-traction for NIH-3T3 cells cultured on SF hydrogels. Cells plated on SF50 hydrogel exhibited significantly high traction stress as compared to SF30; change of functionalization did not show significant change. Also, protrusion traction stress was found to be greater than nuclear traction stress. Put together, our results suggest that surface-stiffness of SF-hydrogel, rather than nature of surface-ligand, regulates both cellular morphology and cellular traction stresses.","PeriodicalId":22140,"journal":{"name":"Soft Materials","volume":"20 1","pages":"45 - 56"},"PeriodicalIF":1.2,"publicationDate":"2021-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/1539445X.2021.1918719","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49199361","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-04-26DOI: 10.1080/1539445X.2021.1909621
Manoj Kumar, Srihari Velaga, Amarjeet Singh
ABSTRACT Thin films of poly (3-hexylthiophene), abbreviated as P3HT, are widely used systems of semiconducting polymer for applications in organic electronic devices. We studied the microstructure of spin-coated thin films of P3HT using grazing incidence x-ray diffraction (GID) by combining high-resolution vertical scan with 2D intensity maps obtained using area detector. Microstructure of the films was quantitatively analyzed in terms of relative crystalline density, texture and coherence length. The structure of the films was relaxed by annealing at 110°C. The relaxed microstructure shows strong thickness dependence. Thick film (61 nm) was highly crystalline and textured. For thin film (32 nm), relative crystalline density was very weak but the coherence length of crystallites was larger and the orientation of crystallites was even more strongly textured. For thick film, the strong increase of crystalline density takes place through fresh nucleation and reorientation of crystallites already present in the films. For thin films, the substrate interaction induced very strong alignment of lamellar crystallites through degeneration of off-oriented crystallites and increased lamellar crystalline coherence. The drastic change of microstructure within a small thickness range is an important aspect to be considered while preparing thin film devices.
{"title":"A study of thickness dependent microstructure of poly (3-hexylthiophene) thin films using grazing incidence x-ray diffraction","authors":"Manoj Kumar, Srihari Velaga, Amarjeet Singh","doi":"10.1080/1539445X.2021.1909621","DOIUrl":"https://doi.org/10.1080/1539445X.2021.1909621","url":null,"abstract":"ABSTRACT Thin films of poly (3-hexylthiophene), abbreviated as P3HT, are widely used systems of semiconducting polymer for applications in organic electronic devices. We studied the microstructure of spin-coated thin films of P3HT using grazing incidence x-ray diffraction (GID) by combining high-resolution vertical scan with 2D intensity maps obtained using area detector. Microstructure of the films was quantitatively analyzed in terms of relative crystalline density, texture and coherence length. The structure of the films was relaxed by annealing at 110°C. The relaxed microstructure shows strong thickness dependence. Thick film (61 nm) was highly crystalline and textured. For thin film (32 nm), relative crystalline density was very weak but the coherence length of crystallites was larger and the orientation of crystallites was even more strongly textured. For thick film, the strong increase of crystalline density takes place through fresh nucleation and reorientation of crystallites already present in the films. For thin films, the substrate interaction induced very strong alignment of lamellar crystallites through degeneration of off-oriented crystallites and increased lamellar crystalline coherence. The drastic change of microstructure within a small thickness range is an important aspect to be considered while preparing thin film devices.","PeriodicalId":22140,"journal":{"name":"Soft Materials","volume":"20 1","pages":"24 - 34"},"PeriodicalIF":1.2,"publicationDate":"2021-04-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/1539445X.2021.1909621","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46111729","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-04-21DOI: 10.1080/1539445X.2021.1906702
Larissa Penteado, V. F. Lopes, T. K. Karam, C. Nakamura, N. Khalil, R. Mainardes
ABSTRACT Perillyl alcohol (POH) is an essential oil found in several plants and presents significant therapeutic and chemo-preventive activity against some tumors. However, it exhibits low aqueous solubility and thereby reduced oral absorption and bioavailability. Nanoencapsulation of POH can be an important tool to overcome such limitations. In this work, chitosan was used for coating poly (ε-caprolactone) nanocapsules for mucoadhesive applications of POH. The nanocapsules were obtained by the nanoprecipitation method and presented a mean diameter of about 330 nm, spherical morphology, polydispersity index of 0.14, zeta potential of +32 mV, and POH encapsulation efficiency of 56%. POH was prolonged released from nanocapsules. In mucoadhesion studies, nanocapsules showed higher adsorption to mucin compared to free POH, possibly due to electrostatic interactions between chitosan and mucin. In the cytotoxicity assay, POH-loaded nanocapsules presented higher IC50 than free POH; however, they were more selective for HT-29 tumor cells than for normal Vero cells. The results demonstrate the potential application of chitosan-coated nanocapsules for the oral administration of POH intended for cancer therapy.
{"title":"Chitosan-coated poly(є-caprolactone) nanocapsules for mucoadhesive applications of perillyl alcohol","authors":"Larissa Penteado, V. F. Lopes, T. K. Karam, C. Nakamura, N. Khalil, R. Mainardes","doi":"10.1080/1539445X.2021.1906702","DOIUrl":"https://doi.org/10.1080/1539445X.2021.1906702","url":null,"abstract":"ABSTRACT Perillyl alcohol (POH) is an essential oil found in several plants and presents significant therapeutic and chemo-preventive activity against some tumors. However, it exhibits low aqueous solubility and thereby reduced oral absorption and bioavailability. Nanoencapsulation of POH can be an important tool to overcome such limitations. In this work, chitosan was used for coating poly (ε-caprolactone) nanocapsules for mucoadhesive applications of POH. The nanocapsules were obtained by the nanoprecipitation method and presented a mean diameter of about 330 nm, spherical morphology, polydispersity index of 0.14, zeta potential of +32 mV, and POH encapsulation efficiency of 56%. POH was prolonged released from nanocapsules. In mucoadhesion studies, nanocapsules showed higher adsorption to mucin compared to free POH, possibly due to electrostatic interactions between chitosan and mucin. In the cytotoxicity assay, POH-loaded nanocapsules presented higher IC50 than free POH; however, they were more selective for HT-29 tumor cells than for normal Vero cells. The results demonstrate the potential application of chitosan-coated nanocapsules for the oral administration of POH intended for cancer therapy.","PeriodicalId":22140,"journal":{"name":"Soft Materials","volume":"20 1","pages":"1 - 11"},"PeriodicalIF":1.2,"publicationDate":"2021-04-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/1539445X.2021.1906702","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46939565","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：