As the current global vaccination against COVID-19 has shown, the administration of conventional needle vaccines on a large scale has its limits. John Kawola, CEO – Global, Boston Micro Fabrication, explains how micro 3D printing microneedles could radically change the world’s response to vaccine distribution.
According to the latest figures from Bloomberg, more than 1.5 billion doses of the COVID-19 vaccine have been administered worldwide.1 These numbers are certainly impressive considering the short time it took from vaccine development to launch, but the past few months have revealed some major logistical challenges of conventional needle vaccines – especially their difficulty in large-scale administration.
Imagine how much easier it could be to distribute if a vaccine could be sent straight to your door and administered through a tiny, painless patch that sticks to your arm. What if vaccines in this form could be sent to impoverished or remote places with no access to health care? Advanced immunization technologies, namely microneedles, are bringing these ideas closer to reality.
The concept of microneedles for vaccination or other drug delivery has been around for some time, but COVID accelerated the demand and research to make it possible. But once the delivery method for microneedles is determined, the industry faces another hurdle: figuring out how to make these tiny, functional devices on a large scale and as inexpensively as traditional vaccination methods. The answer lies in micro-precise 3D printing.
Brings us closer to the future
A team of staff led by Carnegie Mellon University, with the participation of Boston Micro Fabrication (BMF), recently announced that they are developing a novel vaccination approach using low-dose, low-cost, hybrid microneedle array technology.2 The microneedle arrays pass made up of hundreds of tiny needles on a small patch that when applied to the skin can quickly dissolve and deliver the vaccine.
This method of administration requires a small dose amount (less than 1/100 the dose of a traditional vaccine) without the same cold chain storage requirements, which means it can simplify the transportation and storage of vaccines and reduce vaccine bottlenecks and easier distribution of vaccines to people all over the world. These are all concerns that have been exposed in recent months with traditional methods of vaccine use.
Research so far has been promising – it found that the smaller the microneedles, the easier it is to puncture the skin and effectively deliver the vaccine. This realization leads to completely new challenges in the application of micro-needle arrays, and this is where micro-3D printing comes into play.
When smaller is better, bigger challenges arise
As with any type of manufacturing and product development, the smaller the part, the more difficult it is to design, the more expensive it is to manufacture, and the more complicated it is to produce on a scale. This is especially true for traditional manufacturing processes like micro injection molding and CNC machining, where the smaller and more detailed the part, the higher the cost and the longer the wait (and if that’s the case) pandemic taught us all about manufacturing , it is that time is of the essence).
For a long time, additive manufacturing was considered to be more cost-effective and time-efficient, but even 3D printing has traditionally become less attractive as parts become smaller. Challenges with precision and accuracy have blocked innovation for years; Quite simply, there is a lack of viable additive manufacturing technologies that can print with the right resolution and at the right scale.
The high costs associated with traditional manufacturing processes, combined with the lack of powerful 3D printing alternatives, would have broken the promise of microneedle vaccinations before research was complete, had it not been for the latest developments in micro 3D printing . Newer technologies such as stereolithography (SLA), digital light processing (DLP), and a combination of the two known as projection microstereolithography (PµSL) can finally produce ultra-precise, micro-sized parts that are useful for both rapid prototyping and production.
Micro 3D printing for micro needles
Carnegie Mellon invited BMF for the company’s PμSL technology, which can print small parts down to 2 µm resolution. The technology makes it possible to print precisely and efficiently with the right resolution, size, and accuracy … but how exactly micro 3D printing will be used to make the final microneedle vaccine is up for debate.
In a perfect world, PμSL would be used to print the microneedles for end use with a dissolvable, biocompatible material. This would be the most efficient way to get the arrays to production and distribution, and would eliminate the need for other processes such as molding, but this process relies on developing the right dissolvable material. With the passage of the essence, there are also a number of alternatives that should be considered.
One of these options would be to use PμSL to print shape patterns that have enough strength to create shapes that are then used for production. This would allow many microneedles to be 3D printed from the same 3D printed mold and would still be cheaper, more accurate and more precise compared to traditional manufacturing methods.
Although microneedle vaccines are still in the early stages of research and development, there is no doubt that micro 3D printing will play an essential role in making their mass production and distribution a reality. These tiny devices have the potential to completely revolutionize the way the world responds to health crises and immunize millions of people quickly and on a large scale, and while hopefully COVID-19 was a one-off event, innovative vaccine manufacturing and delivery techniques, developed today will ensure a smoother battle against future threats.