Skin Metrology for Optimised Automation of the Ten Bio Device Portfolio

"Everyone knows that tension plays a key role in skin health. Finally, someone has figured out how to incorporate it into a product. This is huge!"
Jon Volmer PhD (Senior Director of Research Biology and Innovation at Medpharm) commenting on the present project's focus product.

The pharmaceutical and cosmetics sector have a need for advanced skin models that mimic the performance of living human skin. This situation is more pronounced than ever given increasing restrictions on animal testing. A solution has arisen from Ten Bio, an award-winning spin-out company from the University of Dundee, who have developed a unique platform that employs human skin within a patent-protected compact platform and that maintains the skin in stretched form. The application of tension in this manner has been found to not only increase the longevity of the product's viability, but also retains a demonstrable level of functionality that competing technologies cannot match, extending potential towards a plethora of additional applications including predictive drug response and even wound healing. Whilst Ten Bio is a young company, their presence on the world stage has already piqued industry's curiosity as to its potential. So much so, that Braham Shroot, the retired head of Research at Galderma, and now Chair of the Advisory Board to Ten Bio, has commented [in relation to Ten Bio's TenSkinTM product]: 'There is nothing like this in the field. You have developed a technology that is going to disrupt the market. This is very exciting."

At present, production of the company's main product is slow and labour intensive at about 4 units per hour. In light of this fact, Ten Bio have engaged with expert industrial product design engineers (i4 Product Design Ltd., (i4PD) Edinburgh) with a view to automating manufacture and have since identified a bottleneck here related to the step involving the mounting and tensioning of skin into its optimal regime. The issue relates to the complex viscoelastic behaviour of the skin and essentially asks the question: how fast we can stretch skin, and by what extent, without damaging it irreversibly in the production process?

We believe that that question can be answered with a modification to the existing instrumentation used for tension testing at Ten Bio, and with the addition of a further sensing system that can either assess directly, or infer in a reliable fashion, the instantaneous level of tension arising for a set stretch at a specific strain rate. The methodology to be applied here relates to fast in-situ and non-invasive optical sensing of the skin sample's state using commercial instrumentation and in-house constructed equipment that will lead to a fast remote and non-destructive assessment of skin sample tension without the need for contact methods and which should serve as a reliable methodology for not only identifying the material constraints that would be rate determining steps limiting production capacity in the manufacturing process, but could also function as a quality assurance step during the automated manufacturing process. The secondee brings expertise in concept formation and instrument development, as well as a suite of state of the art imaging and peripheral tools for characterisation of the product. On the back of the intended measurements we anticipate translation of the main product towards TRL6, together with broadening of the company portfolio in readiness for entering a market worth an estimated $2B. We include one final comment, from Jean Phillippe Therrien PhD (former head of Biology at Tergus Pharaceuticals and now an Advisory Board member at Ten Bio) that underscores this potential for market exploitation: 'We do not typically purchase ready-to-use products such as those provided by Genoskin because there is nothing that those products do that we cannot do ourselves. However, your product is different. We cannot do what you have been able to do."

The individual elements of the work programme will involve:

1: Consultation with the i4PD product development and design team at length in order to assess the most likely next generation architecture for the automated platform and obtain training on the Ten Bio instruments and methods.

2: Prototype development: exploiting the existing instrument platform and architecture at the company with modified electronics and control to facilitate fast cycling and accurate displacement sensing. -> Preliminary measurements.

3. Explore alternative means whereby tension can be assessed/inferred using optical probing as opposed to the contact probe approach presently used, which hampers access in the instrument space.

4. Deploy intense white light source:- an electronically controlled bright LED focussed to the target skin tissue samples and with exposure [period] and duty cycle under full computer control to assess reflective and transmissive components and calibrate with parallel strain gauge based measurements.

5. Examine filter options and the use of polarising plates to assess depth profiling. Reflected light will allow a facility to image the skin surface and assess this for wrinkling signatures that could inform machine vision style control and adjustment to the target tension regime.

6. In assessing risks: scope to move to a more sophisticated measurement using optical coherence tomography if needs be.

7. Implement temperature dependent strain rates measurements by addition of regulated enclosure around the instrument-skin interface.

8. An optimisation approach based on the reliable and widely accepted, but computationally inexpensive Ogden model and analysis will facilitate development of a predictive capacity to assist in the ordering of the manufacturing steps.

9. Generation of new IP covering the extended multi-sample capacity concept. These improvements/supporting data will then be developed for journal dissemination and reported at SID.