Cell motility, contact guidance, and durotaxis

Soft Matter ◽  
2019 ◽  
Vol 15 (24) ◽  
pp. 4856-4864 ◽  
Author(s):  
Jingchen Feng ◽  
Herbert Levine ◽  
Xiaoming Mao ◽  
Leonard M. Sander

Mechanical properties of the substrate play a vital role in cell motility.

2018 ◽  
Author(s):  
Jingchen Feng ◽  
Herbert Levine ◽  
Xiaoming Mao ◽  
Leonard M. Sander

AbstractMechanical properties of the substrate plays a vital role in cell motility. Cells are shown to migrate up stiffness gradient (durotaxis) and along aligned fibers in the substrate (contact guidance). Here we present a simple mechanical model for cell migration, by placing a cell on lattice models for biopolymer gels and hydrogels. In our model cells attach to the substrate via focal adhesions (FAs). As the cells contract, forces are generated at the FAs, determining their maturation and detachment. At the same time, the cell also allowed to move and rotate to maintain force and torque balance. Our model, in which the cells only take the information of forces at the FAs, without a prior knowledge of the substrate stiffness or geometry, is able to reproduce both durotaxis and contact guidance.


2018 ◽  
Vol 877 ◽  
pp. 294-298 ◽  
Author(s):  
Kundan Patel ◽  
Jay Patel ◽  
Piyush Gohil ◽  
Vijaykumar Chaudhary

Composite materials play a vital role in many industrial applications. Researchers are working on fabrication of new composite materials worldwide to enhance the applicability of these materials. The present study aimed to investigate the effect of Nano clay loading as filler on the mechanical properties of the bamboo fiber yarn reinforced polyester composite. Five different types of composite specimen were prepared with Nano clay loadings of 0 to 4 % weight fraction using hand lay-up technique. It was observed that the composite sheet with 1 wt % nano clay content exhibited the optimized tensile and flexural strength. However the mechanical properties tend to decrease with addition of nano clay content from 2 to 4 wt %. In spite of that the values of mechanical properties with 2 and 3 wt % nano clay content is higher than 0 wt % nano clay content.


Author(s):  
Lebogang Lebea ◽  
Harry M Ngwangwa ◽  
Dawood Desai ◽  
Fuluphelo Nemavhola

The initial stability after implantology is paramount to the survival of the dental implant and the surface roughness of the implant plays a vital role in this regard. The characterisation of surface topography is a complicated branch of metrology, with a huge range of parameters available. Each parameter contributes significantly towards the survival and mechanical properties of 3D-printed specimens. The purpose of this paper is to experimentally investigate the effect of surface roughness of 3D-printed dental implants and 3D-printed dogbone tensile samples under areal height (Ra) parameters, amplitude parameters (average of ordinates), skewness (Rsk) parameters and mechanical properties. During the experiment, roughness values were analysed and the results showed that the skewness parameter demonstrated a minimum value of 0.596%. The 3D-printed dental implant recorded Ra with a 3.4 mm diameter at 43.23% and the 3D-printed dental implant with a 4.3 mm diameter at 26.18%. Samples with a complex geometry exhibited a higher roughness surface, which was the greatest difficulty of additive manufacturing when evaluating surface finish. The results show that when the ultimate tensile stress (UTS) decreases from 968.35 MPa to 955.25 MPa, Ra increases by 1.4% and when UTS increases to 961.18 MPa, Ra increases by 0.6%. When the cycle decreases from 262142 to 137433, Ra shows that less than a 90.74% increase in cycle is obtained. For 3D-printed dental implants, the higher the surface roughness, the lower the mechanical properties, ultimately leading to decreased implant life and poor performance.


2021 ◽  
pp. 004051752110466
Author(s):  
Tong Yang ◽  
Min Luo ◽  
Zhuanyong Zou ◽  
Pibo Ma

The surface membrane plays a vital role in bearing loads of flexible inflatable composites. In this work, the mechanical properties of the upper and lower surfaces of inflatable composites and spacer fabrics were studied. It focused on the changes in mechanical properties of surfaces of spacer fabrics with different structures after coating and damage characteristics. The results show that the PVC resin improves the mechanical properties of the surface, which penetrates into the structure to make the yarns bond to each other and adhere to the resin on the surface. And compared with knitted structures, composite membranes with a woven structure have the characteristics of specific strength. This provides data accumulation for performance research of flexible inflatable composites, finite element calculation analysis, and the experimental reference for broadening the application in military pontoons and marching tents.


Author(s):  
Abel L. Thangawng ◽  
Rodney S. Ruoff ◽  
Jonathan C. Jones ◽  
Matthew R. Glucksberg

It has been reported that the mechanical properties of a substrate influence cell motility, morphology, and adhesion [1–3]. This work is an attempt to move a step further beyond cells’ sensing the mechanical properties of their environment, by determining whether the secretion and assembly of laminin extracellular matrix is regulated by the mechanical environment in which the cell is placed. We hypothesize that this matrix then influences the behavior of the cell, particularly with regard to its motility.


Author(s):  
FA Anene ◽  
CN Aiza Jaafar ◽  
I Zainol ◽  
MA Azmah Hanim ◽  
MT Suraya

The sterling mechanical properties of titanium alloys have distinguished them as an essential material for varied applications especially in biomedical fields. The combination of good corrosion resistance in addition to light weight, non-toxicity and an outstanding biocompatibility makes them a sought-after material for production of medical implants. Owing to the surging demand for durable implants, it has become exigent for increased developmental researches on biomaterials to be accelerated. This will result in significant increase in implant production and Ti alloys will play a vital role among the several materials presently in use. Hence, this review critically analysed the important roles Ti alloys have played thus far in the implant production industry and recent development of titanium-based alloys with low elastic modulus similar to human bones as well as improved biocompatibility and wear resistance.


2019 ◽  
Vol 14 ◽  
pp. 155892501986880 ◽  
Author(s):  
Liyong Tian ◽  
Di Wang ◽  
Qufu Wei

Tires might be the first technically significant composite out of rubber and play a vital role in the overall performance of a car. The essential functions of a tire rely to a great extent on the properties of tire cords. Polyester and nylon cords make up the majority of synthetic fibers used in tires. A new kind of polyester cord has been developed combining the performance characteristics of both polyester and nylon cords. This article examines the dynamic mechanical properties of this nylon-like polyester tire cord by adopting dynamic mechanical analysis, Instron, and DISC fatigue experiments, as well as its dynamic adhesion property using flex fatigue experiment. It demonstrated that the dynamic complex modulus of the nylon-like polyester cord was higher than that of nylon 6 cord but lower than that of standard polyester cord, which was a favorable characteristic when it came to replacing nylon 6 cord with nylon-like polyester cord in tires. Under cyclic loading, hysteresis loss of nylon 6 cord > nylon 66 cord > nylon-like polyester cord > standard polyester cord was observed. In the DISC experiment, nylon-like polyester had a similar compression resistance property to that of nylon 6 cord. At a temperature below 85°C, nylon-like polyester cord maintained roughly the same level of residual ratio of dynamic adhesion, but beyond this temperature point, nylon 6 exhibited a better performance.


eLife ◽  
2018 ◽  
Vol 7 ◽  
Author(s):  
Luca Melli ◽  
Neil Billington ◽  
Sara A Sun ◽  
Jonathan E Bird ◽  
Attila Nagy ◽  
...  

Nonmusclemyosin 2 (NM-2) powers cell motility and tissue morphogenesis by assembling into bipolar filaments that interact with actin. Although the enzymatic properties of purified NM-2 motor fragments have been determined, the emergent properties of filament ensembles are unknown. Using single myosin filament in vitro motility assays, we report fundamental differences in filaments formed of different NM-2 motors. Filaments consisting of NM2-B moved processively along actin, while under identical conditions, NM2-A filaments did not. By more closely mimicking the physiological milieu, either by increasing solution viscosity or by co-polymerization with NM2-B, NM2-A containing filaments moved processively. Our data demonstrate that both the kinetic and mechanical properties of these two myosins, in addition to the stochiometry of NM-2 subunits, can tune filament mechanical output. We propose altering NM-2 filament composition is a general cellular strategy for tailoring force production of filaments to specific functions, such as maintaining tension or remodeling actin.


Robotica ◽  
2006 ◽  
Vol 25 (3) ◽  
pp. 341-349 ◽  
Author(s):  
Mike Tao Zhang ◽  
Ken Goldberg

SUMMARYAlthough parallel-jaw grippers play a vital role in automated manufacturing, gripper surfaces are still designed by trial-and-error. This paper presents an algorithmic approach to designing gripper jaws that mechanically align parts in the vertical (gravitational) plane. We consider optimal edge contacts, based on modular trapezoidal segments that maximize contact between the gripper and the part at its desired final orientation. Given then-sided 2D projection of an extruded convex polygonal part, mechanical properties such as friction and center of mass, and initial and desired final orientations, we present anO(n3logn) numerical algorithm to design optimal gripper jaws. We also present anO(nlogn) algorithm to compute tolerance classes for these jaws, and report on an online implemented version of the algorithm and physical experiments with the jaws it designed. This paper extends earlier results that generated optimal point contacts [M. T. Zhang and K. Goldberg, “Gripper point contacts for part alignment,”IEEE Trans. Robot. Autom.18(6), 902–910 (2002)].


Sign in / Sign up

Export Citation Format

Share Document