Stem Cell Differentiation & Genomic Processes in Response to Bioactive Nanotopography

Lead Research Organisation: University of Southampton
Department Name: Development Origin of Health and Disease

Abstract

With an increasing ageing population the clinical requirement to replace degenerated tissues, such as musculoskeletal tissue, is a major socio-economic requirement. A key issue is an understanding of stem cell activity on different materials, specifically a need to understand how stem cells behave on a material surface. We have generated novel data that shows small changes in the shape of a material can relate to large changes in cell behaviour when they are grown on the material surface. These changes in material shape can be at the nanoscale (1 x 10-9 meters); for examples pits, pillars and grooves with widths and heights of under 100 nm can cause cell alignment, increases in adhesion and even cause total non-adhesion (non-contact) through adjustments of spacing and aspect ratio. Other effects nanoscale designs can have on cells are changes in cytoskeleton (proteins involved in cell adhesion, spreading, metabolism and signalling), cell growth and the function of the cell (differentiation). Stem cells are immature cells that have the ability to differentiate into a number of mature cell types. For example, stem cells from bone can differentiate into cells for bone formation and maintenance (osteoblasts and osteocytes) or cells for cartilage formation and maintenance (chondroblasts and chondrocytes), ligament and tendon formation (fibroblasts) and a number of other cell types (fat, endothelial, epithelial). The understanding of the environmental cues allowing cells to chose one type (bone or fat - referred to as lineage) over another would be of great advantage for stem cell biologists and subsequently for materials researchers and tissue engineers could then optimise material design for e.g. hip and knee replacements. In the replacements of load bearing implants for bone (such as the knee and hip), once the material is implanted, bone stem cells in the bone marrow (called mesenchymal or skeletal stem cells) differentiate to become fibroblasts due to lack of appropriate cues from the material. Thus, the material is surrounded by soft tissue rather than hard bone. Over time this causes implant failure leading to older patients undergoing complicated secondary (revision) surgery. Here, we plan to investigate how materials can pass nanoscale mechanical signals to the cell nucleus and how this leads to changes in DNA organisation and subsequent cell differentiation - a process known as direct mechanotransduction. We would view changes in structural proteins of the nucleus (nucleoskeleton) with changes in cell spreading on nanomaterials. These changes could then be related to changes in DNA positioning and gene regulation alongside studies of differentiation. Very little is know about what in their environment triggers stem cell differentiation, we believe that surface shape, also known as topography (like a mountain surface can be flat, rugged, smooth and bumpy), is important. If we can understand these processes we can produce better materials (informed design) that will encourage direct bone bonding (apposition) to an implant, thus removing the need for revision surgery. This would save patient worry, surgical time and the NHS millions of pounds.

Technical Summary

Topographical changes as small as 20 nm can be the difference between bone formation or lack of differentiation in stem cells. We intend to exploit this exquisite control to study the skeletal stem cell / material interface. It has been shown that the interphase nucleus has relative organisation, with chromosomes being arranged into discrete territories. Whereupon, it has then been speculated that by changing interphase chromosome positioning, the probability of transcription is altered. While research in this area is in its infancy, we have spent the last five years collecting data towards a grant application and have a unique system with which to study this without the use of invasive methodology. It is known that the cytoskeleton is central to mechanotransduction, both indirect (signalling cascades) and direct (force transduction). Our previous studies with skeletal stem cells and nanotopography have shown that topography confers changes in cell spreading and cytoskeletal organisation upon the cells. Furthermore, our previous studies with fibroblasts have shown changes in nuclear organisation and gene regulation with changes in cytoskeletal organisation. Here, it is intended than nanotopography will be used to cause changes in nuclear organisation (lamin nucleoskeleton, chromosome territories and methylation patterns) and differentiation will be monitored. Thus, the topography would be used to induce mechanotransductive effects in mesenchymal stem cells. Liking these results to microarray data and using resources such as the Stanford Source, we can plot where in the genome changes due to direct mechanotransduction are occurring. This will allow us to observe if large changes in interphase chromosome positioning due to direct mechanotransduction lead to large changes in gene regulation. Potentially, this could be a major route of cell differentiation and help us to develop materials, through rational design, to elicit directed differentiation.

Publications

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Title "An understanding of the apparatus of bodily production in the stem cell and regenerative medicine space 
Description A series of artworks, photographs and a book on "An understanding of the apparatus of bodily production in the stem cell and regenerative medicine space Developed over 2010 to 2012 and curated in 2013 
Type Of Art Artwork 
Year Produced 2013 
Impact "An understanding of the apparatus of bodily production in the stem cell and regenerative medicine space" Formed a major exhibition- a series of artworks and a book 
URL https://www.southampton.ac.uk/medicine/business_partnership/success_stories/intra_actions_and_reconf...
 
Description We have demonstrated the unique ability of nanotopographical surfaces, in the absence of chemical cues, to modulate stem cell function. Specifically, we have shown, for the first time in the world, the ability of a specific nanotopgraphy to maintain the stem cell phenotype of a bone stem cell.

This work has been patented, extensively published and offers new approaches to culture cells in the absence of chemical cues. The identified approach can be applied to culture surfaces, implants and surfaces

The work is now informing our work under UKRMP II musculoskeletal research and development of new approaches to 3D Print scaffold structures.
Exploitation Route This work has been patented, extensively published and offers new approaches to culture cells in the absence of chemical cues.
The identified approach can be applied to culture surfaces, implants and surfaces with significant commercial opportunities.
Sectors Healthcare,Manufacturing, including Industrial Biotechology,Pharmaceuticals and Medical Biotechnology

 
Description This work of novel nanotopographical surfaces to modulate stem cell fate and function has been patented and offers new approaches to culture cells in the absence of chemical cues. The identified approach can be applied to culture surfaces, implants and surfaces
First Year Of Impact 2011
Sector Healthcare
 
Title Retention of Stem Cell Phenotype 
Description Surface topographies for maintenance of stem cell phenotype 
IP Reference WO2010094944 
Protection Patent application published
Year Protection Granted 2010
Licensed No
Impact Allowed additional research through grant support
 
Description Cheltenham Science Festival - Central Exhibit in Discover Zone 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Public/other audiences
Results and Impact The Stem Cell Mountain featured in 'Doc Brown's Lab' (in keeping with the 2015 Back to the Future Theme) at the famous Cheltenham Science Festival Discover Zone. The team interacted with an estimated 1800 visitors over 6 days. Received feedback such as the following: "Great explanation from volunteers about the stem cell model. My Year 6 pupils could then explain the purpose of the model - great" and "That's how you teach science!"
Year(s) Of Engagement Activity 2015
URL http://www.cheltenhamfestivals.com/science/
 
Description Invited Speaker - DASCS 2017 Conference, Odense 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Other audiences
Results and Impact 2nd November 2017: Invited Speaker - DASCS (Danish Stem Cell Society) 2017 Conference, Odense - Skeletal Cell Based Strategies for Bone Repair - Opportunities and Challenges
Year(s) Of Engagement Activity 2017
 
Description Invited lecture at the Medical Research Council Lifecourse Epidemiology Unit - Musculoskeletal Lecture Series 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Third sector organisations
Results and Impact Online Seminar: "Regenerative Musculoskeletal Medicine: Skeletal cell based strategies for bone regeneration from bench to clinic" on Tuesday 26th January 2021
Year(s) Of Engagement Activity 2021
 
Description Open Conference "Stem cells for bone regeneration: state-of-the-art research and solutions" 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact Invited Speaker - Bonebank Conference, Odense, Denmark. "Skeletal stem cells for bone tissue regeneration.".
The audience were peer scientists, clinicians and industrialist to inform, educate and debate developments in translational bone research.
Year(s) Of Engagement Activity 2016
 
Description Scaffolds and cells - making replacement body parts in the lab - Exhibit at the BBSRC Great British Bioscience Festival 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Public/other audiences
Results and Impact Engaged over 6500 visitors from across the UK as part of the BBSRC run GBBF. EPSRC grant generated the centre piece of our exhibit - the Stem cell mountain - a large interactive pinball machine built in collaboration with Winchester Science Centre to communicate the concept of Stem Cell Potential. In response to the feedback question 'Tell us something from your visit that you found particularly interesting' the answer 'Stem Cells' was one of the most frequently given. Through a conversation at this exhibition a talented international MSc student from Queen Mary's was inspired to commence a PhD project (self-funded) in my group.
Year(s) Of Engagement Activity 2014
 
Description Science Day at University of Southampton 
Form Of Engagement Activity Participation in an open day or visit at my research institution
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Public/other audiences
Results and Impact Science Day ('Stem Cell Mountain' & Bone regenerative medicine display') at University of Southampton - 14/03/15. (Open to the general public - 1000+ visitors)
Year(s) Of Engagement Activity 2008,2011,2013,2015,2016
 
Description Speaker at UKRMP Conference UK 
Form Of Engagement Activity A magazine, newsletter or online publication
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact Invited Speaker - Inaugural UK Regenerative Medicine Conference, London. "Size matters - Harnessing biomimetic materials for skeletal tissue engineering."
The audience were peer scientists, clinicians and industrialist to inform, educate and debate developments in translational bone research.
Year(s) Of Engagement Activity 2016
 
Description Stem Cell Mountain at Bestival Music Festival Science Tent 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Public/other audiences
Results and Impact Stem Cell Mountain at the Bestival Music Festival Science Tent (4 days) - exhibit in shared Science Tent, mixed Festival audience (mainly general public and especially young people 17-25) Measure 1: visitors passing stand; 1400 per day = 5600 Measure 2: visitors interacting with researchers on stand; 500 per day = 2000 Particularly notable was the impact of this activity on the researchers themselves and how they viewed the importance of their own research. For example one researcher reported: "This festival was great to see how amazed people are about the potential of stem cells"
Year(s) Of Engagement Activity 2015
 
Description Stem Cell Mountain at the Glastonbury Music Festival Science Tent 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Public/other audiences
Results and Impact Stem Cell Mountain exhibit in shared Science Tent, mixed Festival audience (academics, post-docs, science specialists, general public, families and young people) Measure 1: visitors passing stand; 1100 per day = 5500 Measure 2: visitors interacting with researchers on stand; 500 per day = 2500 Engaged classically hard to reached audience. Quote: "I was considering doing a PhD at one point - I didn't think I'd reconsider it here"
Year(s) Of Engagement Activity 2015
 
Description Winchester Science Festival 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Public/other audiences
Results and Impact Stem Cell Mountain at a three day up and coming science festival. Engaged largely family audience and science festival talk attendees Measure 1: visitors passing stand; 300 per day = 900 Measure 2: visitors interacting with researchers on stand; 150 per day = 450
Year(s) Of Engagement Activity 2015