Browsing by Author "Akella, Arun"

Now showing 1 - 2 of 2
  • Thumbnail Image
    Item
    Biomechanics of Smooth Muscle Cell Differentiation: Experimental Study using an Innovative in vitro Mechanical System
    (Office of the Vice Chancellor for Research, 2013-04-05) Akella, Arun
    Identifying mechanisms that regulate different smooth muscle cell (SMC) gene expressions is critical for understanding the SMC phenotype and genotype in both physiological and pathological conditions, as SMCs’ primary role is to control the slow, involuntary movement of hollow organs such as blood vessels, airways, gastrointestinal, urinary and reproductive tracks. Previous in vitro studies indicated that specific genes were lost and there was a slight change in the physical structure of the SMCs. This was due to the overwhelming complexity of the in vivo environment which could not be accurately simulated in vitro. It is hypothesized that if SMCs are cultured in vitro by subjecting them to controlled mechanical stresses (cyclic strains at various frequencies and time durations), they will retain the same level of gene expression as in vivo. The objective is to evaluate subsequent changes in the SMC lineage based on gene expression changes. To accomplish this, a novel cell stretching device is being developed that will stimulate cultured SMCs by allowing both culturing and stretching of cells on the same unit. This also effectively reduces the working time needed by researchers to complete each run. The expected outcome will be the effects of different mechanical stresses on cell survival over time. Specifically, SMC lineage assessment and western blot analysis will be done. The results will hopefully prove that in vivo conditions of SMCs can be successfully simulated in vitro. The research will help in comparing the oxidative stresses, hyperglycemia, lipotoxicity and calcification responses on specific SMC types in vitro, and offer new insights into the genetic and environmental bases of SMC diseases. This is critical for research in areas such as drug screening and tissue engineering. For future research, co-culture systems may be studied as the device is capable of culturing two cell-types in the same environment.
  • Thumbnail Image
    Item
    A novel in vitro stretch device for simulating in vivo conditions
    (2018-05) Akella, Arun; El-Mounayri, Hazim
    Biological cells are constantly subjected to mechanical forces such as tension, compression and shear. The importance of these forces in mediating cell signals, maintenance of lineages, promoting embryonic cell differentiation and tissue engineering is only now coming into focus. It has been shown that stretch stimulus can influence growth, differentiation, as well as tissue strength and integrity. Most stretch systems built to understand more of these phenomena suffer from shortcomings, as accurately replicating the in vivo environment is quite challenging. Many of the devices currently available are very expensive as well as limited to a single application. The objective of this thesis is to design, manufacture, test, and validate a novel uniaxial cyclic cell stretch device that overcomes most of the major limitations of existing systems, and to experimentally demostrate that uniaxial cyclic stretch causes a shift towards in vivo characteristics of smooth muscle cells. The stretch mechanism is driven by a single servo motor which makes its operation simple and straight forward. Coolworks Lite, a proprietary software of the servo motor supplier, is used to control the motor and LabVIEW is used to obtain feedback from the sensors. Validation for the stretch machine was done by evaluating the performance of the device against engineering requirements. Methods were suggested to improve shortcomings that were encountered. Also, the machine's unique design allows its extension to a biaxial stretch unit while keeping the same driver platform, a concept for which has been discussed and illustrated.