Mohammed, T (2017) Evaluating the effects of acoustic stimulation on fibroblast cell migration and muscle fibre formation. Doctoral thesis, Liverpool John Moores University.

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Abstract

Cells are known to interact and respond to external mechanical cues and recent work has shown that application of mechanical stimulation, delivered via acoustic vibration, can be used to control complex cell behaviours. Much of the work in this area has focused on the effects of mechanical stimulation upon bone cells. Very little has been done to investigate the effects of mechanical stimulation on other cell types. Therefore, could mechanical stimulation be used to accelerate the wound healing process? Could mechanical stimulation be used to encourage muscle cell growth? The data generated in this thesis will be completely new knowledge which will help us develop our understanding of mechanotransduction and help us develop new approaches and devices to address medical challenges such as accelerating wound healing process, increasing muscle mass in diseases associated with muscle degeneration and aging. The aim of this research was to investigate the effects of mechanical stimulation upon the migratory and morphological properties of three different fibroblast cells and muscle cells namely; human lung fibroblast cells (LL24), subcutaneous areolar/adipose mouse fibroblast cells (L929), Human dermal fibroblast cells (HDF) and C2C12P12 muscle cells. Using a speaker-based system, the effects of mechanical stimulation (0-1600Hz for 5 and 20 minutes) on wound/scratch assays, the mean cell migration distance (µm), actin and vinculin organisation, cell viability, muscle fibre diameters and the effects of temperature were investigated. The results show that 100Hz acoustic vibration can enhance cell migration, wound healing in LL24 and L929 cells and possible increase muscle fibre diameters although there was no significance, the trends were repeatable. Mechanical stimulation was also found to promote changes to the morphology of LL24 and L929 cell lines, particularly the formation of lamellipodia and filopodia. Overall lamellipodia was the most prominent actin structure displayed by the lung cell (LL24), whereas filopodia was the most prominent actin feature displayed by the fibroblast derived from subcutaneous areolar/adipose tissue. Vinculin appeared to be more punctate in L929 cells compared to LL24 cells. Mechanical stimulation at all the frequencies used here was found not to affect cell viability. However, as the frequency increased, the temperature also increased. These results suggest that low-frequency acoustic vibration may be used as a tool to manipulate the mechano-sensitivity of cells to control cell migration and to enhance the diameters of muscle fibres.

Item Type:	Thesis (Doctoral)
Uncontrolled Keywords:	Acoustic vibration; Mechanical stimulation; Fibroblast cell migration; Actin reorganisation; Wound healing; fiber formation
Subjects:	R Medicine > RM Therapeutics. Pharmacology T Technology > TJ Mechanical engineering and machinery
Divisions:	Engineering
Date Deposited:	12 Jun 2017 08:44
Last Modified:	19 Dec 2022 15:41
DOI or ID number:	10.24377/LJMU.t.00006047
Supervisors:	Murphy, MF, Burton, D and Lilley, F
URI:	https://researchonline.ljmu.ac.uk/id/eprint/6047

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