To finish the project we created a roadmap of our process:
The previous five weeks we have been working on the “Bones” project. Together with coach Dafydd Visscher (later referred to as Dafydd) we have been looking for a universal so-called ‘scaffold’ to help burn victims with reconstructing their damaged ears. At the start, the aim of the project was a bit vague to us. We thought that we were ‘just another group of students’ who would work on something that wasn’t genuinely useful for the VUmc. When we got further into the process, we started understanding the meaning of the project more and more (what does a “general” or “ideal” pattern actually mean in this context?). And more important, it became clearer what our function was within the project. The deeper we got into the project, and thus the more we learned about the subject, the more exciting it became.
The first week was all about researching, and trying to understand the project’s goal. This start was a bit rough since the information was very new to us. We tried researching as much as we could, and tried scheduling meetings with the coaches. It was very nice to look into information other than ‘design-information’ for once. This project is in a way very related to the minor, but concerning the bio-medical part it is completely different. This was refreshing and in good balance with the other project of the minor. As for the following three/four weeks, it was all about finding a pattern, and looking into software that could provide this pattern for us. It was nice for us to work in Amsterdam with a lot of experts on different fields. When we got stuck somewhere in the process, there were always people wanting to help and try different things with us. That’s why we tried going to Amsterdam as much as we can. Also, our coach Dafydd Visscher was always open to questions and suggestions, which made us feel very welcome at the VUmc and which stimulated us to do even more for the project.
The Science Fair felt like icing on the cake. We had our stories straight and we were really proud of what we achieved, so we felt proud presenting our results at the Science Fair. A lot of interested people approached us with interesting questions, which we discussed thoroughly. Some of them were so excited about the project that they kept asking information, reaching subjects which went beyond our acquired knowledge, and raising even more questions along the way, which mattered to the project (e.g. “How is the dissolved biodegradable material later expelled from the body?”). Thanks to the presence of Dafydd all of the “extra” questions could be answered as well as allowing us to go even more into detail with the people who came to listen to our story. Concluding, the entire Science Fair was both a nice presentation of our achievements, and an extra learning moment for all of us.
Even though we managed to finish the project the way we wanted to, with realistic results, the project was very short. Five weeks isn’t enough, given the fact that the first week was focussed on understanding the assignment and biology behind it, and the last week was all about the Science Fair. This leaves three weeks for the actual project, and although this isn’t very long, we are proud to have achieved our initial goals. We all felt a bit sad when the five weeks were over, which is probably a good thing.
Overall the project was very refreshing, especially next to the other minor project which was more focused on construction, mechanics and form-concepts. It was also a very nice project because we had to tackle a challenging problem. We loved working with the people from VUmc, and we think our results are probably the best we could have achieved in this amount of time. We look back at the project with joy and pride, and obviously we are really glad with the grade we got. A special thanks to Dafydd for guiding and helping us, and ofcourse to everyone else involved in the process from VUmc.
Yesterday, the 27th of October, the Science Fair took place at the faculty of Industrial Design at the University of Technology in Delft. At this event we presented our 4 week project on developing a general extracellular matrix of ear cartilage.Above you see a picture of the team members and our PHD coach. From left to right: Patrick Sengalrayan, Feline Hunink, Dafydd Visscher, Jelmer van de Scheur and Femke Maas. Unfortunately Ennio Donders couldn’t be present.
Most important was our final model, which was also 3D printed with a Gypson printer (left image). Furthermore we showed a prototype before the final model (right image) which was a simplified print because the CAD models couldn’t handle the complex inital models.
We finished our project by writing a manual (see also the visual below) on how to create such an extended general extracellular model for ear cartilage, so they can use it also for other bone or cartilage types. Our model will be printed by an american company who can print on a mirco-scale (the above models for example were scaled from 5 mm to 30 cm so they were easy to present) in both collagen as pcl. Afterwards cells are grown in a lab and inserted in the lagunes.
Our process went well but it also had some difficulties which we could solve eventually. You can read and see more about our process in our reflection on the project.
The scaffold is printed by a 3D-bioprinter present at the VUmc. Since this printer is quite complicated we need to know more about it so we can prepare our files before printing. We read the printer’s manual & we asked some questions in the meeting with the expert group.
How will the bioprinter eventually print our scaffold?
A PCL outer layer (shell) is printed to prevent contraction of the natural polymer. Daffyd assumes that the cells connect to the PCL layer which makes contraction impossible. The inside matrix consists of the natural polymer, which is a gelatine-like substance with cells.
Bounderies of Bio-Printer
The bioprinter can only read an STL file as a whole, while temperature and other factors have to be controlled per printed layer. Therefore the STL file has to be devided into layers and each layer has to be uploaded to the printer seperately. The printer doesn’t work with STL files but there is a special Bio Cad program for this. The printer works with g-code. What they didn’t try yet is uploading a dwg or dfx file.
How are the images/3D files made of a piece/slice of ear cartillage?
This is done with a laserscanning microscope, which is much more precise than a CT-scan. This is needed because the intercellular matrix of ear cartillage is very small. MRI is also a possibility, however with the laserscanning microscoop the collageen can be distinguished from the elastine.
On the second Friday (2nd of October) there was a discussion on the research we had read and the upcoming plans and scope of the project. Furthermore other core experts of the project were introduced.
Some conclusions: To what extent should our scaffold be similair real ear cartillage? Answer: We assume this can be a simplified scaffold, however it should be tested by printing the scaffolds and letting the cells generate new cartillage wich takes approximately 2 months. Only the cartilage should be mimicked. The perichondrium and skin are other layers. Other parts, like cells will grow from the bioink of the bioprinter.
Ideas – With the research as background, we generated several ideas to edit the original STL Ear cartillage file. Can we for example make a negative which is simpler to edit or can we use a 2D image of the pattern and extrude that later? The next steps are to test different approaches on their feasibillity. We concluded that a formula to find an average pattern would be convienent.
After gaining enough knowledge about (ear) cartilage, 3D and bio printing techniques we could finalize our project proposal. See the objectives and approach, taken from the proposal, below:
- Find the general pattern of ear cartilage
- Recreating matrix/lattice of ear cartilage in simplified form while taking into account cell environment requirements, 3D & bio-printer constraints and strength of the lattice concerning possible future trauma to the ear.
- Final goals: Create a standard model of the ear cartilage lattice and put it in a (helix) shell of the ear, so bio-ink can be printed in between the lattice in future project developments.
- Using Rhino, GOM, 3-matic and/or other available software to simplify the model & create a new model to print with.
- Use Mathlab or/and other pattern recognition software to find a general pattern in the Ear-cartilage STL files ( files available at VUmc 3Dlab Amsterdam, obtained by scanning ears with CT-technology and transferred by experts to STL files).
- Testing (multiple/ different) scaffolds on strength with Finite Element techniques in 3D modelling software (for example GOM, 3-matic and/or Solidworks).
- Doing research about anatomy of ear cartilage and trying to find requirements for the natural environment to stimulate cells to grow new cartilage.
- Using 3Dprinters to print tests of our simplified scaffold and combine them with cells (done by VUmc).
So in the upcoming weeks…we will search for and use a programs that can find general patterns in STL files or images. For that we will contact experts at the TU Delft. In the 3D/Cad-programs we will try out different commands to make the model more simple/ to find a general pattern/to try finite elements on the initial STL file. Furthermore to set-up a list of requirements that our model has to meet we will look at the manual of the VUmc Bio-printer and we have to select a 3D-printer. The bio-printer for example is very complex and can only be used by an expert.
A part of our project takes place at the VUmc which enables us to use more advanced computers and enables us to discuss and cooperate with the experts of the 3D innovation lab.
To proceed with the tests we needed more knowledge about (ear) cartilage and the problem with surgery of damaged ears. Therefore we went through several papers including the topics:
- Different types of ear cartilage and other bone structures & their functions
- Development of the external ear (pinna) (embryology stage)
- Developments & procedure of reconstruction surgery techiques
- 3D techniques used to print ear-scaffolds
- 3D printing used and future advantages in the health sector
- Notions: Scaffold, Lattice, Chondrytes, Perichondrium
- Problem with damaged ears and currently used procedures
Read more about the anatomy of the ear concerning the research focus in About Cartilage.
On the first Friday (25th of September) we were invited to the VUmc in Amsterdam.They introduced us to their 3D Innovation lab which is managed by the jaw-surgery-department.
Different printed models of jaws and skeletons areprinted to test before the actual surgery.
Besides the lab there is also a bio-printer and a ZCorp-like printer. The Bio-printer has three printer heads. One with air, used to generate pressure. A second one for printing bio-gel with cells and the last one prints dissolvable PCL to create a supporting structure/lattice. STL-files don’t work on the printer, so a special biocad program is used with g-codes. In the future they want to develop printers which are sterile.
The ZCorp-like printer prints different layers of plaster-like material, which are merged at specific points by a binding material. The bio-printer prints hydrogel or bio-degradable materials.
Recap – A new approach to ear reconstruction is needed since it is very difficult to create a lasting and realistic ear. 3D printing offers new opportunities to create ear-scaffolds and our task is to do tests with printed matrixes of ear cartilage and to find a general and simplified pattern of the ear cartilage matrix.
During this day Dafydd Visscher and Ernst-Jan Bos introduced us on the topics and problems of the project and gave us an introduction on the PHD research. Our scaffold should for example mimic real cartilage since cells react differently on different textures/structures and forms. The form of our mimicked (bio-degradable) intercellular ear cartilage should signal the cells to make new ear-cartilage when the mimicked cartilage is broken down. The PCl dissolves in two years, but the cells should start growing a new lattice after only two months. We need to know how ear cartilage differs from other cartilage in function and form for example cartilage present in the nose. Another challenge is to see if we can print two layers that can interconnected. For that we need to do research on how cells are layered. The project has STL-files of CT-scans of ear cartilage available for this. See a 3D-model of this file:
For next week our challenge is to read multiple papers on ear cartilage and ear reconstruction surgery methods. And what are our first ideas on creating this mimicked cartilage? We will also do some starting tests with adapting the STL ear cartilage files.