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Artikel ; Online: Protocol for measuring mechanical properties of live cells using atomic force microscopy.

Singh, Surya Bansi / Rajput, Shatruhan Singh / Patil, Shivprasad / Subramanyam, Deepa

STAR protocols

2024 Band 5, Heft 1, Seite(n) 102870

Abstract: Atomic force microscope (AFM) is a powerful and versatile tool to determine the physical properties of cells. The force-distance curves obtained from AFM experiments can be used to determine the stiffness and viscoelastic properties of cells. Here, we ... ...

Abstract	Atomic force microscope (AFM) is a powerful and versatile tool to determine the physical properties of cells. The force-distance curves obtained from AFM experiments can be used to determine the stiffness and viscoelastic properties of cells. Here, we present a protocol for the determination of viscoelasticity from live cells such as Drosophila hemocytes or mouse embryonic stem cells using AFM. This protocol has potential application in determining the physical properties of cells in healthy and diseased conditions. For complete details on the use and execution of this protocol, please refer to Mote et al. (2020),
Mesh-Begriff(e)	Animals ; Mice ; Microscopy, Atomic Force/methods ; Mechanical Phenomena
Sprache	Englisch
Erscheinungsdatum	2024-02-07
Erscheinungsland	United States
Dokumenttyp	Journal Article
ISSN	2666-1667
ISSN (online)	2666-1667
DOI	10.1016/j.xpro.2024.102870
Datenquelle	MEDical Literature Analysis and Retrieval System OnLINE

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Artikel ; Online: Direct and Simultaneous Measurement of the Stiffness and Internal Friction of a Single Folded Protein.

Deopa, Surya Pratap S / Rajput, Shatruhan Singh / Kumar, Aadarsh / Patil, Shivprasad

The journal of physical chemistry letters

2022 Band 13, Heft 40, Seite(n) 9473–9479

Abstract: The nanomechanical response of a folded single protein, the natural nanomachine responsible for myriad biological processes, provides insight into its function. The conformational flexibility of a folded state, characterized by its viscoelasticity, ... ...

Abstract	The nanomechanical response of a folded single protein, the natural nanomachine responsible for myriad biological processes, provides insight into its function. The conformational flexibility of a folded state, characterized by its viscoelasticity, allows proteins to adopt different shapes to perform their function. Despite efforts, its direct measurement has not been possible so far. We present a direct and simultaneous measurement of the stiffness and internal friction of the folded domains of the protein titin using a special interferometer based atomic force microscope. We analyzed the data by carefully separating different contributions affecting the response of the experimental probe to obtain the folded state's viscoelasticity. Above ∼95 pN of force, the individual immunoglobulins of titin transition from an elastic solid-like native state to a soft viscoelastic intermediate.
Mesh-Begriff(e)	Connectin ; Elasticity ; Friction ; Immunoglobulins ; Muscle Proteins/physiology
Chemische Substanzen	Connectin ; Immunoglobulins ; Muscle Proteins
Sprache	Englisch
Erscheinungsdatum	2022-10-05
Erscheinungsland	United States
Dokumenttyp	Journal Article
ISSN	1948-7185
ISSN (online)	1948-7185
DOI	10.1021/acs.jpclett.2c02257
Datenquelle	MEDical Literature Analysis and Retrieval System OnLINE

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Artikel ; Online: Mechanism of Adhesion of Natural Polymer Coatings to Chemically Modified Siloxane Polymer.

Joseph, Emmanuel / Rajput, Shatruhan Singh / Patil, Shivprasad / Nisal, Anuya

Langmuir : the ACS journal of surfaces and colloids

2021 Band 37, Heft 9, Seite(n) 2974–2984

Abstract: Surface coatings play an important role in improving the performance of biomedical implants. Polydimethylsiloxane (PDMS) is a commonly used material for biomedical implants, and surface-coated PDMS implants frequently face problems such as delamination ... ...

Abstract	Surface coatings play an important role in improving the performance of biomedical implants. Polydimethylsiloxane (PDMS) is a commonly used material for biomedical implants, and surface-coated PDMS implants frequently face problems such as delamination or cracking of the coating. In this work, we have measured the performance of nano-coatings of the biocompatible protein polymer silk fibroin (SF) on pristine as well as modified PDMS surfaces. The PDMS surfaces have been modified using oxygen plasma treatment and 3-amino-propyl-triethoxy-silane (APTES) treatment. Although these techniques of PDMS modification have been known, their effects on adhesion of SF nano-coatings have not been studied. Interestingly, testing of the coated samples using a bulk technique such as tensile and bending deformation showed that the SF nano-coating exhibits improved crack resistance when the PDMS surface has been modified using APTES treatment as compared to an oxygen plasma treatment. These results were validated at the microscopic and mesoscopic length scales through nano-scratch and nano-indentation measurements. Further, we developed a unique method using modified atomic force microscopy to measure the adhesive energy between treated PDMS surfaces and SF molecules. These measurements indicated that the adhesive strength of PDMS-APTES-SF is 10 times more compared to PDMS-O
Sprache	Englisch
Erscheinungsdatum	2021-03-01
Erscheinungsland	United States
Dokumenttyp	Journal Article ; Research Support, Non-U.S. Gov't
ZDB-ID	2005937-1
ISSN	1520-5827 ; 0743-7463
ISSN (online)	1520-5827
ISSN	0743-7463
DOI	10.1021/acs.langmuir.1c00047
Datenquelle	MEDical Literature Analysis and Retrieval System OnLINE

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Artikel: Mechanism of Adhesion of Natural Polymer Coatings to Chemically Modified Siloxane Polymer

Joseph, Emmanuel / Rajput, Shatruhan Singh / Patil, Shivprasad / Nisal, Anuya

Langmuir. 2021 Mar. 01, v. 37, no. 9

2021

Abstract	Surface coatings play an important role in improving the performance of biomedical implants. Polydimethylsiloxane (PDMS) is a commonly used material for biomedical implants, and surface-coated PDMS implants frequently face problems such as delamination or cracking of the coating. In this work, we have measured the performance of nano-coatings of the biocompatible protein polymer silk fibroin (SF) on pristine as well as modified PDMS surfaces. The PDMS surfaces have been modified using oxygen plasma treatment and 3-amino-propyl-triethoxy-silane (APTES) treatment. Although these techniques of PDMS modification have been known, their effects on adhesion of SF nano-coatings have not been studied. Interestingly, testing of the coated samples using a bulk technique such as tensile and bending deformation showed that the SF nano-coating exhibits improved crack resistance when the PDMS surface has been modified using APTES treatment as compared to an oxygen plasma treatment. These results were validated at the microscopic and mesoscopic length scales through nano-scratch and nano-indentation measurements. Further, we developed a unique method using modified atomic force microscopy to measure the adhesive energy between treated PDMS surfaces and SF molecules. These measurements indicated that the adhesive strength of PDMS-APTES-SF is 10 times more compared to PDMS-O₂-SF due to the higher number of molecular linkages formed in this nanoscale contact. This lower number of molecular linkages in the PDMS-O₂ indicates that only fewer numbers of surface hydroxyl groups interact with the SF protein through secondary interactions such as hydrogen bonding. On the other hand, a larger number of amine groups present on PDMS-APTES surface hydrogen bond with the polar amino acids present on the silk fibroin protein chain, resulting in better adhesion. Thus, APTES modification to the PDMS substrate results in improved adhesion of nano-coating to the substrate and enhances the delamination and crack resistance of the nano-coatings.
Schlagwörter	adhesion ; atomic force microscopy ; biopolymers ; deformation ; delamination ; energy ; fibroins ; hydrogen ; hydrogen bonding ; oxygen ; polydimethylsiloxane
Sprache	Englisch
Erscheinungsverlauf	2021-0301
Umfang	p. 2974-2984.
Erscheinungsort	American Chemical Society
Dokumenttyp	Artikel
Anmerkung	NAL-AP-2-clean
ZDB-ID	2005937-1
ISSN	1520-5827 ; 0743-7463
ISSN (online)	1520-5827
ISSN	0743-7463
DOI	10.1021/acs.langmuir.1c00047
Datenquelle	NAL Katalog (AGRICOLA)

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Buch ; Online: Direct and simultaneous measurement of stiffness and internal friction of single folded protein

Deopa, Surya Pratap S / Rajput, Shatruhan Singh / Kumar, Aadarsh / Patil, Shivprasad

2022

Abstract: The nanomechanical response of a folded single protein, the natural nanomachine responsible for myriad biological functions, provides insight into its function. The conformational flexibility of a folded state, characterized by its viscoelasticity, ... ...

Abstract	The nanomechanical response of a folded single protein, the natural nanomachine responsible for myriad biological functions, provides insight into its function. The conformational flexibility of a folded state, characterized by its viscoelasticity, allows proteins to adopt different shapes to perform functions. Despite efforts, its direct measurement has not been possible so far. We present a direct and simultaneous measurement of stiffness and internal friction of folded domains of protein titin using a special interferometer based Atomic FOrce Microscope. We analysed the data by carefully separating different contributions affecting the response of the experimental probe to obtain folded state's viscoelasticity. Above ~ 95 pN of force, the individual immunoglobulins of titin transition from an elastic solid-like native state to a soft viscoelastic intermediate. Comment: 20 pages, 12 figures
Schlagwörter	Physics - Biological Physics ; Condensed Matter - Soft Condensed Matter
Thema/Rubrik (Code)	612
Erscheinungsdatum	2022-08-03
Erscheinungsland	us
Dokumenttyp	Buch ; Online
Datenquelle	BASE - Bielefeld Academic Search Engine (Lebenswissenschaftliche Auswahl)

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Artikel ; Online: Validity of point-mass model in off-resonance dynamic atomic force microscopy.

Rajput, Shatruhan Singh / Deopa, Surya Pratap S / Ajith, V J / Kamerkar, Sukrut C / Patil, Shivprasad

Nanotechnology

2021 Band 32, Heft 40

Abstract: The quantitative measurement of viscoelasticity of nano-scale entities is an important goal of nanotechnology research and there is considerable progress with advent of dynamic atomic force microscopy. The hydrodynamics of cantilever, the force sensor in ...

Abstract	The quantitative measurement of viscoelasticity of nano-scale entities is an important goal of nanotechnology research and there is considerable progress with advent of dynamic atomic force microscopy. The hydrodynamics of cantilever, the force sensor in AFM measurements, plays a pivotal role in quantitative estimates of nano-scale viscoelasticity. The point-mass (PM) model, wherein the AFM cantilever is approximated as a point-mass with mass-less spring is widely used in dynamic AFM analysis and its validity, particularly in liquid environments, is debated. It is suggested that the cantilever must be treated as a continuous rectangular beam to obtain accurate estimates of nano-scale viscoelasticity of materials it is probing. Here, we derived equations, which relate stiffness and damping coefficient of the material under investigation to measured parameters, by approximating cantilever as a point-mass and also considering the full geometric details. These equations are derived for both tip-excited as well as base-excited cantilevers. We have performed off-resonance dynamic atomic force spectroscopy on a single protein molecule to investigate the validity of widely used PM model. We performed measurements with AFMs equipped with different cantilever excitation methods as well as detection schemes to measure cantilever response. The data was analyzed using both, continuous beam model and the PM model. We found that both models yield same results when the experiments are performed in truly off-resonance regime with small amplitudes and the cantilever stiffness is much higher than the interaction stiffness. Our findings suggest that a simple PM approximation based model is adequate to describe the dynamics, provided care is taken while performing experiments so that the approximations used in these models are valid.
Sprache	Englisch
Erscheinungsdatum	2021-07-12
Erscheinungsland	England
Dokumenttyp	Journal Article
ZDB-ID	1362365-5
ISSN	1361-6528 ; 0957-4484
ISSN (online)	1361-6528
ISSN	0957-4484
DOI	10.1088/1361-6528/ac0cb1
Datenquelle	MEDical Literature Analysis and Retrieval System OnLINE

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Artikel: Flexible Piezoelectric Nanogenerators Based on One-Dimensional Neutral Coordination Network Composites

Prajesh, Neetu / Sharma, Vijay Bhan / Rajput, Shatruhan Singh / Singh, Chandan Kumar / Dixit, Prashant / Praveenkumar, Balu / Zarȩba, Jan K. / Kabra, Dinesh / Ogale, Satishchandra / Boomishankar, Ramamoorthy

ACS sustainable chemistry & engineering. 2022 July 22, v. 10, no. 30

2022

Abstract: Metal–organic coordination polymers are modular systems whose structures can be modified in numerous ways to introduce and influence non-linear optical and electrical properties. However, their full potential as piezoelectric nanogenerators for self- ... ...

Abstract	Metal–organic coordination polymers are modular systems whose structures can be modified in numerous ways to introduce and influence non-linear optical and electrical properties. However, their full potential as piezoelectric nanogenerators for self-powered electronics is yet to be uncovered. Here, we report a Zn(II)-based ferroelectric one-dimensional coordination network {[Zn(L¹)(bpy)]·(H₂O)₁.₅}∞ (1) derived from a flexible dicarboxylate ligand [PhPO(NH-(C₆H₄COOH))₂] (L¹H₂) and 2,2′-bipyridine as a co-ligand. The origin of polarization in 1, despite its neutral structure, is due to the polyhedral distortions around the Zn(II) center as revealed by ab initio calculations. The presence of polarizable domains was visualized by piezoresponse force microscopy (PFM) experiments. Also, from the PFM studies, a sizable converse piezoelectric coefficient (d₃₃) value of 19.4 pm/V was noticed for 1, which is unprecedentedly high for the class of neutral-network coordination polymers. Furthermore, flexible composite devices comprising a thermoplastic polyurethane (TPU) polymer with different weight percentages (wt %) of 1 were prepared and examined for application as piezoelectric nanogenerators. Notably, the champion device of this series (poled 5 wt % 1-TPU composite) exhibits a highest open-circuit voltage of 5.6 V and power density output of 14.6 μW/cm².
Schlagwörter	atomic force microscopy ; dicarboxylic acids ; electric potential difference ; electronics ; green chemistry ; ligands ; polyurethanes ; thermoplastics
Sprache	Englisch
Erscheinungsverlauf	2022-0722
Umfang	p. 9911-9920.
Erscheinungsort	American Chemical Society
Dokumenttyp	Artikel
ISSN	2168-0485
DOI	10.1021/acssuschemeng.2c02296
Datenquelle	NAL Katalog (AGRICOLA)

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Artikel ; Online: The nano-scale viscoelasticity using atomic force microscopy in liquid environment.

Rajput, Shatruhan Singh / Deopa, Surya Pratap S / Yadav, Jyoti / Ahlawat, Vikhyaat / Talele, Saurabh / Patil, Shivprasad

Nanotechnology

2020 Band 32, Heft 8, Seite(n) 85103

Abstract: We measured viscoelasticity of two nanoscale systems, single protein molecules and molecular layers of water confined between solid walls. In order to quantify the viscoelastic response of these nanoscale systems in liquid environment, the measurements ... ...

Abstract	We measured viscoelasticity of two nanoscale systems, single protein molecules and molecular layers of water confined between solid walls. In order to quantify the viscoelastic response of these nanoscale systems in liquid environment, the measurements are performed using two types of atomic force microscopes (AFMs), which employ different detection schemes to measure the cantilever response. We used a deflection detection scheme, available in commercial AFMs, that measures cantilever bending and a fibre-interferometer based detection which measures cantilever displacement. The hydrodynamics of the cantilever is modelled using Euler-Bernoulli equation with appropriate boundary conditions which accommodate both detection schemes. In a direct contradiction with many reports in the literature, the dissipation coefficient of a single octomer of titin I27
Mesh-Begriff(e)	Connectin/chemistry ; Elasticity ; Hardness ; Hydrodynamics ; Microscopy, Atomic Force ; Nanotechnology ; Proteins/chemistry ; Viscosity ; Water/chemistry
Chemische Substanzen	Connectin ; Proteins ; Water (059QF0KO0R)
Sprache	Englisch
Erscheinungsdatum	2020-12-23
Erscheinungsland	England
Dokumenttyp	Journal Article
ZDB-ID	1362365-5
ISSN	1361-6528 ; 0957-4484
ISSN (online)	1361-6528
ISSN	0957-4484
DOI	10.1088/1361-6528/abc5f3
Datenquelle	MEDical Literature Analysis and Retrieval System OnLINE

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Buch ; Online: Elastic response of poly(ethylene glycol) polymer chains studied using dynamic atomic force microscopy

Ahlawat, Vikhyaat / Rajput, Shatruhan Singh / Patil, Shivprasad

2019

Abstract: Stretching response of polymer chains under external force is crucial in understanding polymer dynamics under equilibrium and non-equilibrium conditions. Here we measure the elastic response of poly(ethylene glycol) using a lock-in based amplitude ... ...

Abstract	Stretching response of polymer chains under external force is crucial in understanding polymer dynamics under equilibrium and non-equilibrium conditions. Here we measure the elastic response of poly(ethylene glycol) using a lock-in based amplitude modulation-AFM with sub-angstrom amplitude in both low and high frequency regime. Appropriate analysis that takes into account the cantilever geometry and hydrodynamic loading effects of oscillating cantilever in liquid, relates X signal of lock-in amplifier linearly to stiffness.Stiffness data extracted from X signal was compared with stiffness from derivative of conventional "static" force extension curves. For stiffness data from X signal, fitting to standard entropic model of WLC gives a physically meaningful value of persistense length and also follows scaling behaviour of WLC. Entropy dominated conformational transition with its characteristic V-shaped signature was observed at arount 250 pN. Accurate measurement of stiffness enabled us in understanding the thermodynamics of conformational changes.
Schlagwörter	Condensed Matter - Soft Condensed Matter ; Physics - Biological Physics
Thema/Rubrik (Code)	621
Erscheinungsdatum	2019-04-10
Erscheinungsland	us
Dokumenttyp	Buch ; Online
Datenquelle	BASE - Bielefeld Academic Search Engine (Lebenswissenschaftliche Auswahl)

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Artikel ; Online: Resistive Switching in HfO

Antad, Vivek / Shaikh, Parvez A / Biswas, Abhijit / Rajput, Shatruhan Singh / Deo, Shrinivas / Shelke, Manjusha V / Patil, Shivprasad / Ogale, Satishchandra

ACS applied materials & interfaces

2021 Band 13, Heft 45, Seite(n) 54133–54142

Abstract: High-performance nonvolatile resistive random access memories (ReRAMs) and their small stimuli control are of immense interest for high-speed computation and big-data processing in the emerging Internet of Things (IoT) arena. Here, we examine the ... ...

Abstract	High-performance nonvolatile resistive random access memories (ReRAMs) and their small stimuli control are of immense interest for high-speed computation and big-data processing in the emerging Internet of Things (IoT) arena. Here, we examine the resistive switching (RS) behavior in growth-controlled HfO
Sprache	Englisch
Erscheinungsdatum	2021-11-02
Erscheinungsland	United States
Dokumenttyp	Journal Article
ISSN	1944-8252
ISSN (online)	1944-8252
DOI	10.1021/acsami.1c15082
Datenquelle	MEDical Literature Analysis and Retrieval System OnLINE

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