HELP Vol. 02: Let’s Create Samples of Artificial Blood Vessels and Stent Covers for the Exhibition in China!
The second edition of “HELP” has begun! For this installment, we are preparing samples of artificial blood vessels and stent covers to be showcased at “Medtec China 2024,” a medical device manufacturing event taking place in China from September 25 (Wednesday) to 27 (Friday).
2024 Medtec China
18th International Medical Device Design and Manufacturing Technology Exhibition
(Supporting Japanese, Chinese, and English)
Participants for This Edition of “HELP”
Joining us this time is our new staff member, “Jin,” adding even more power to “HELP”! We look forward to delivering an enhanced experience.
Since the upcoming exhibition is focused on medical devices, I’d like to create tubular nanofibers and have many people see them!
I want to be able to spin tubular nanofibers, too!
Alright, let’s ask spinning expert Nakatsuka-san for help right away!
I’ll join it and learn.
Nakatsuka-san! Please help us!!
We want to learn how to create tubular nanofibers!
Good idea. Tubular nanofibers are ideal for making artificial blood vessels and stent covers in the medical field.
I’d like to practice making samples of artificial blood vessels and stent covers.
What solutions are commonly used?
For artificial blood vessels, PU is often used, and for stent covers, PCL is commonly chosen.
I’ve never spun PCL before, so I’d like to try using PCL.
Me too.
Then how about Jin-san and I work on PU?
Sounds good!
When making tubular samples, let’s use the “Mandrel Collector” from the optional collectors!
Preparing the Solution for Spinning Tubular Nanofibers
We prepared the solution using the ratio that Nakatsuka-san taught us.
• Group A (Ko, Jin)’s solution → 12.5 wt% PU
•Group B (Wang, Masagaki)’s solution → 12 wt% PCL
How thick are blood vessels?
Blood vessels are classified by size, with those 6mm or larger considered large-diameter, and those under 6mm classified as small-diameter. Incidentally, the production of small-diameter artificial blood vessels is a global challenge.
Can our equipment make small-diameter vessels?
Of course! NANON can create various size of Tubular Nanofibers for blood vessels.
Alright, I’ve decided! Let’s make both large and small ones this time!
< Mandrel Rod Sizes >
Diameter: 10mm / 6mm / 2mm
Let’s try spinning PU (artificial blood vessels)!
Starting with the 6mm rod. You can begin by using the following parameters.
[Parameters]
・Voltage: 18kV
・Flow Rate: 1ml/h
・Spinning Distance: 150mm
・Needle Size: 27G
Oh, right! When you spin just PU, the sample won’t come off the rod once it’s done!
What?! Really?! Why is that?
PU adheres tightly to the rod, leaving no gap at all.
What?!So, we just need to create a gap, right?
Exactly! Now, how do we create that gap?
How about spinning a water-soluble solution first? Then, spin PU on top of that. Once the sample is finished, you can soak it in water, and the water-soluble layer will dissolve, creating a gap between the rod and the PU, making it easier to remove…?!
Bingo! That’s correct. So, what water-soluble solution should we use first?
How about PEO?
That’s a great choice! PEO is commonly used.
I see! I learned something new!
Thanks to Nakatsuka-san’s advice, Group A’s experiment progressed smoothly.
6ｍｍ
Soaked the PU sample into water like this.
Let’s Try Spinning PCL (Stent Cover)!
We would like to use a 22G needle. Let’s see if we can finish spinning in a shorter time with using a thicker needle and increasing the feed rate.
Group B decided to use a 22G needle.
Do we need to spin a water-soluble solution first when spinning PCL as well?
No need. PCL will come off instantly if you soak it in ethanol.
Really?! Sounds fun!
It really came off in just a second! (Though I forgot to capture that important moment…!)
Let’s check the membrane thickness!
Since we have the chance, we also measured the membrane thickness.
Summary
We successfully created tubular nanofiber samples using PU and PCL.
Group A
To remove PU from the rod, spinning a water-soluble solution first makes it easier to remove, such as PEO
Note: Using ultrasonic cleaning will make the process even faster!
Group B
1. We successfully spun PCL using a 22G needle with a feed rate of 1.5ml/h.
2. Soaking the sample in ethanol allows for easy removal from the rod.
Thanks to everyone, we were able to practice creating tubular nanofibers! Thank you very much.
We can confidently show them at the exhibition!
At Medtec China 2024, where Wang and Gao will participate, we will not only display the samples we created but also conduct a demonstration of nanofiber spinning using our most popular NANON machine. Additionally, we will offer free consultations on spinning, so please come and visit us. Don’t miss seeing the growth of our team members!
Tell us! HELP！
We hope you look forward to the next time!