Rapid assembly of living micro-tissues with holographic optical tweezers; Cell 'LEGO' for regenerative medicine

Lead Research Organisation: University of Nottingham
Department Name: Sch of Pharmacy

Abstract

The headline or sound bite for this project is 'laser-guided positioning of live cells and building of living micro-tissues - a new, cell scale manufacturing process for pharmaceutical testing and regenerative medicine'. The project showcases how scientists from seemingly unrelated backgrounds in tissue engineering and optical physics are collaborating to develop new healthcare technologies. The driver for the project is the increasing need to produce living human tissues, in the culture dish, with structures and functions that are as close as possible to those in the body and to use these in vitro tissues to more effectively test, develop and improve new and existing medicines and therapies. This approach can minimize use of animals in research and also reduce potentially costly, both health and economic, failures with new medicines.

Our ability to achieve this ambitious goal of manufacturing living micro-tissues with lasers is underpinned by an instrument called an optical tweezers. Optical tweezers, invented in the 1980s exploit a phenomenon, whereby a tightly focused beam of laser light creates a localized force at its point of focus and has the effect of attracting small particles towards it - a so called optical trap or optical trapping. Suspending the particles within fluid gives a damping force producing a single (laser) beam optical trap that is stable in three dimensions (3D) - by moving the beam of laser light, the trapped particle can be also moved and controlled in multiple directions and subsequently positioned at defined points/locations with 'laser precision'. A range of different types and sizes of particles can be trapped and moved including, 2 micron (one 500th of a millimetre) glass beads to live human cells, which are typically 10 microns (one 100th of a millimetre) in size. Importantly, the properties of the laser, in terms of its power and wavelength are such that it causes little or no damage to cells and certainly in the time taken (seconds/minutes) to trap and move them.

An evolution of this instrument is the holographic optical tweezers, where the single laser beam is split to create multiple traps, each capable of holding and moving particles. This is done using a spatial light modulator (SLM), a component typically found in an overhead and/or data projector. The SLM acts as a diffractive optical element, or hologram, and can be continuously updated via a computer program. Thus, multiple traps can be created in 3D and each trap independently controlled and positioned to create predetermined configurations and patterns. Using conventional microscope optics and a joy stick or iPad touch screen, the traps can be visualized in real time and controlled with the dexterity of a 'virtual hand'.

Here, we will use this technology to exert hitherto unattainable levels of control over the movements and positioning of live cells, with the predefined precision akin to natural processes of tissue development and formation. With dynamic, precision control at the scale of the individual cell, we will show how holographic optical tweezers can be used to manufacture definable and tuneable, 3D micro-tissues; micro-tissue components, such as cells or small (~5 micron) polymer particles containing drugs, can be assembled together within minutes in a manner similar to building with 'cell LEGO'. With inherent control over manufacturing complexity we can deliver 'simple' 3D cell aggregates with applications in drug discovery and pharmaceutical testing, each aggregate consistent with the next, assembled with an exact number of cells and drug-loaded microparticles. This will be the focus of this phase of the project.

Developing the project further we will also seek to push the boundaries for manufacture of more complex, bespoke structures that mimic specific tissues like liver, skin, heart etc and can be used to better understand disease processes and develop new therapies.

Planned Impact

Progress and outputs from this project will be shared with the academic community via the usual methods of peer-reviewed publications and presentation (oral/poster) at research conferences and invited seminars. Significantly, the multidisciplinary nature of the project and involvement of investigators and researchers from the biological and physical sciences will ensure that our research findings will be disseminated across diverse audiences.

A key stage in the project is development and evolution of the manufacturing with (laser) light process and involves a number of technical innovations and biological observations that we fully intend to share through our demonstrated (and aspired to) publications in journals such as, Nature Biotechnology, Nature Photonics, Tissue Engineering, Journal of Controlled Release, Soft Matter, Lab-on-a-Chip, and Developmental Biology.

In terms of research conferences and workshops, we have demonstrated participation and presentations to many that are relevant to this project including, Tissue Engineering International and Regenerative Medicine Society (TERMIS), World Biomaterials Congress etc. The investigators are routinely invited to give more informal seminars, often to groups that are working directly on research relevant to the project, providing a significant opportunity to share, discuss and develop data in small focussed groups.

Recent data, training/demonstrations and 'mini-projects' in new research and techniques (e.g, holographic optical tweezers) is also currently shared with students and researchers and includes; University of Nottingham MSc Stem Cell Technology, the EPSRC Doctoral Training Centre in Regenerative Medicine, the BBSRC Doctoral Training Partnership
(http://cmswip01.nottingham.ac.uk/doctoral-training-centres/doctoral-training-centres.aspx) and the EPSRC Centre for Innovative Manufacturing in Regenerative Medicine (http://www.epsrc.ac.uk/funding/centres/innovativemanufacturing/Pages/imrcmedicine.aspx)

Engaging the wider community and the public we have active outreach programmes that includes; 'After-Schools Clubs' (e.g. the School of Pharmacy's award-winning After School Science Club for Year 5 and 6 primary school children, where we have discussed previously stem cells and tissue engineering), public lectures and exhibitions - School of Pharmacy presented an exhibit at the Royal Society's 2013 Summer Science Exhibition in London - 'Biology Builders', showcasing our research and innovation in regenerative medicine. Notably, this involved hands-on interaction with the holographic optical tweezers via a remote, iPad-controlled live interface, between the exhibit and the tweezers back Nottingham and this was extremely well received.

We also regularly participate in university 'Open Days' and 'May Fest' and give tours and interactive demonstrations of our research. Research is also publicized via university media offices (e.g www.nottingham.ac.uk/news/pressreleases/2012/march/artificial-womb-unlocks-secrets-of-early-embryo-development.aspx) and via research group websites . We shall also engage with and consult the EPSRC Press Office. The university and investigators also maintain Twitter accounts and frequently use this to communicate research outputs, conference attendance etc

Publications

10 25 50
 
Description This project is ongoing and runs from February 2014 to September 2015. We are using an instrument called Holographic Optical Tweezers, which uses low energy laser light to move small objects, including living cells. We are using this approach to move stem cells and with the precision of a laser, position live cells into definable configurations and build small (micro) scale cellular structures that mimic arrangements of cells in the body.

The major goal of the project is to develop this
Exploitation Route With precision manufacture of cell-scale/micro-tissue products this can be readily taken up by the pharmaceutical industry in developing new drugs and can also impact on the reduction, replacement and refinement of animals in medical research.

For the stem cell and regenerative medicine industries it provides tunable cell models for modelling diseases and developing therapies.
Sectors Healthcare,Manufacturing, including Industrial Biotechology,Pharmaceuticals and Medical Biotechnology

URL http://sine.ni.com/cs/app/doc/p/id/cs-16720
 
Description This project is ongoing, but we have been developing the technology over several years, allied to other projects and 'in-house' small value (?5-10K) research awards. High profile outputs included the Royal Society Summer Exhibition 2013, where we had an exhibit 'The Biology Builders' showcasing our approaches towards developing the field of tissue engineering /regenerative medicine. The holographic optical tweezers were a key part of the exhibit and had a live interface between the exhibition
First Year Of Impact 2013
Sector Healthcare,Manufacturing, including Industrial Biotechology,Pharmaceuticals and Medical Biotechnology
Impact Types Societal,Economic

 
Description CDT REGEN MED (LOUGHBOROUGH - KEELE - NOTTINGHAM)
Amount £49,000 (GBP)
Organisation University of Leeds 
Department Faculty of Engineering
Sector Academic/University
Country United Kingdom
Start 03/2015 
End 03/2015
 
Title Optical Tweezers 
Description Holographic optical tweezers - using laser light to move living cells and build cell-scale structures/micro-tissues 
Type Of Material Technology assay or reagent 
Year Produced 2014 
Provided To Others? Yes  
Impact Royal Society Summer Exhibition EPSRC Manufacturing with Light research award 
 
Description Embryo implantation 
Organisation University of Cambridge
Department Gurdon Institute
Country United Kingdom 
Sector Academic/University 
PI Contribution Developing environments to study the process of mammalian embryo implantation
Collaborator Contribution Monitoring embryo development on engineered surfaces
Impact Publication in Nature Communications Patent application
Start Year 2010
 
Description Laser tweezers 
Organisation University of Glasgow
Country United Kingdom 
Sector Academic/University 
PI Contribution Building optical tweezers instrument. Development of cell applications
Collaborator Contribution Technological development of the instruments to work with living cells
Impact Publications in 2009, 2015 Royal Society Summer Exhibition, 2013 EPSRC Manufacturing with Light award
Start Year 2007
 
Description Biology Builders 
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 Royal Society Summer Exhibition - showcasing our development of regenerative medicine via technology including optical tweezers and 3D bioprinting

Members of the team were invited back to give seminars at the 2014 Royal Society Summer Exhbition. Work also featured on BBC Children's TV programme and Channel 4's Embarrassing Bodies.
Year(s) Of Engagement Activity 2013