3d bioprinting

Allevi Author: NJIT Bioprints Vascularized Tissue

NJIT allevi guvendiren vascular vasculature vein 3d bioprint bioprinted bioprinter

We are VERY excited to announce the latest addition the Allevi Author Club; the Guvendiren Lab from the New Jersey Institute of Technology.

Dr. Guvendiren’s lab focuses on creating novel bioinks for tissue engineering and regenerative medicine applications with a focus on 3D bioprinting. Their most recent paper, published in Acta Biomaterialia and titled “3D bioprinting of complex channels within cell-laden hydrogels”, explores their new approach to 3D bioprinting vasculature into 3D tissue.

There are many different methods for creating microchannels within constructs, including electrospinning, fiber bonding, and casting solvents into molds. However these techniques don’t allow for precise control of channel size, shape or location. They can also be time-consuming and restrictive in the number of cell lines that you are able to work with simultaneously.

The Guvendiren lab is exploring a new approach to creating these channel-laden tissues using their Allevi 2 bioprinter. In their paper, they explore a method of 3D bioprinting sacrificial bioinks into cell-laden hydrogels (pluronic into methacrylated alginate/methacrylated hyaluronic acid to be specific). This technique allows them to create custom channel geometries, control channel thickness and tune the hydrogel rigidity. They also explored a super cool technique wherein they alter the printhead speed in order to create channels of differing diameters.

Their images from confocal scanning show strong endothelial cell (HUVEC) attachment to the channel walls and depict the final 3D bioprinted vein construct.

HUVEC vascular channel vein 3d bioprinted bioprint allevi NJIT guvendiren

This research explores important techniques for creating tunable microchannels within 3D tissues. We can imagine a future wherein these methods are used to create 3D bioprinted organs with custom and complex vascular networks. It could also be used to create custom 3D models to study disease progression and test drug efficacy and toxicity. Amazing work, Guvendiren Lab!!

Click through to read their material characterization and learn more about their bioprinting approach: https://www.sciencedirect.com/science/article/pii/S1742706119301515.

Allevi Author - Valentine's Day Edition: GWU Bioprints Heart Tissue

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George Washington University joins the #AlleviAuthor club with their new paper titled, “Use of GelMA for 3D printing of cardiac myocytes and fibroblasts” and published in Journal of 3D Printing in Medicine.

First let’s review some basics about your heart! Heart tissue is composed of two main cell types; cardiac fibroblasts (CFB) & cardiomyocytes (CMC).

 
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Cardiomyocytes are the contracting cells which allow the heart to pump. Each cardiomyocyte needs to contract in coordination with its neighboring cells to efficiently pump blood from the heart, and if this coordination breaks down then the heart may not pump at all.

Fibroblast cells give support to the muscle tissue. They are unable to provide forceful contractions like cardiomyocytes, but instead are largely responsible for creating and maintaining the extracellular matrix which forms the mortar in which cardiomyocyte bricks are embedded. Fibroblasts also play a crucial role in responding to injury by creating collagen while gently contracting to pull the edges of the injured area together.

In previous academic studies, tests of pure populations of cardiomyoctes have failed to stay viable making it difficult to study the heart in a lab setting. In their recent paper, the team at George Washington University set out to determine how 3D bioprinting affects these two types of cells and if there is a way to create viable 3D tissue in the lab by bioprinting both CMCs and CFBs in tandem.

The team studied the effects of temperature, pressure, bioink composition, and UV exposure to determine the best conditions for 3D bioprinting heart muscle.

Through LIVE/DEAD assays, bioluminescence imaging and morphological assessment, they determined that cell survival within a 3D bioprinted CMC-laden GelMA construct was MORE sensitive to extruder pressure and bioink composition than the fibroblast-laden constructs. Also they determined that BOTH cell types were adversely impacted by the UV curing step. And finally they determined that using a mixture of cardiomyocytess and cardiac fibroblasts increased viability of the tissue- showing that CMCs <3 CFBs.

Cheers to the team at GWU! Their research creates an important foundation for future studies of 3D bioprinted heart tissue.

Read their paper here.

Allevi Author: 3D‐Printed Sugar Stents to Aid in Surgery

Microvascular anastomosis (or the method of surgically connecting blood vessels) is a common part of many reconstructive and transplant surgical procedures.

There are multiple methods for connecting two veins together including coupling devices, surgical glue, and surgical suturing but each method has it’s downsides; coupling devices can face rejection from the body, glue can introduce contamination or clotting to the vein, and suturing (the most commonly accepted practice) is a delicate and time consuming procedure.

 
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During the suturing procedure, surgeons are in a race against the clock to quickly connect the veins together to ensure that organs continue to receive proper blood flow. However, blood vessels of differing shapes and sizes can sometimes make this procedure difficult to maneuver in a timely fashion.

 
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In their recent paper titled, “3D‐Printed Sugar‐Based Stents Facilitating Vascular Anastomosis”, researchers at Brigham and Women’s Hospital & The University of Nebraska Lincoln collaborated using an Allevi 2 bioprinter to find a solution to aid in the intricacies surrounding this procedure.

Here, dissolvable sugar‐based stents are 3D printed as an assistive tool for facilitating surgical anastomosis. The non-brittle sugar‐based stent holds the vessels together during the procedure and are dissolved upon the restoration of the blood flow. The incorporation of sodium citrate minimizes the chance of thrombosis, and the dissolution rate of the sugar‐based stent can be tailored between 4 and 8 min.

 
allevi 2 3d bioprinter fabricates sugar stents to aid in surgical procedure
 

3D printing is an ideal method for constructing these stents because you are able to quickly design and create custom geometries to fit the patient’s vessels.

The effectiveness of the printed sugar‐based stent was assessed ex vivo and found to be a fast and reliable fabrication method that can be performed in the operating room.

This new method of aiding surgeons is a game-changer as it is dissolvable, tunable, and completely customizable. In the future, your doctor could quickly print out stents to match your exact vein geometry which would reduce the time spent on the operating table and under anesthesia.

Interested in learning more about this novel technique? You can read the full paper here: https://onlinelibrary.wiley.com/doi/abs/10.1002/adhm.201800702?af=R&

The Allevi Academy

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By Lauren McLeod, Bioengineer: 

Here at Allevi, we’re always looking to the future - how to prepare for future challenges, how to revolutionize and improve on current research and methodologies...but sometimes it’s necessary to reflect on the past.  We took some time to think about the education experiences that got us to where we are today. Most of us conjured up memories of an impressionable teacher, exciting project, or even an awesome field trip that sparked an excitement for learning and science.  We thought to ourselves, “Why not have bioprinting be the seed of students’ excitement and learning for the field of bioengineering?”

We’re excited to announce the launch of The Allevi Academy- the first step in preparing today’s students for the regenerative medicine challenges of the future!  We partnered with high school teachers, university professors, and educators across the world to produce the best, most streamlined and accessible curriculum possible to arm teachers with the materials and resources needed to introduce their students to bioprinting.  

Through our curriculum, students gain experience with cutting edge biotechnology, putting them light years ahead of their peers as they enter college and the workforce.  According to the US Bureau of Labor Statistics, bioengineers hold the third fastest growing job in the United States, with a projected ten year growth of 61.7% by 2020. Our curriculum gives students a competitive advantage in this burgeoning field.

The curriculum enables students to develop valuable skills across multiple engineering disciplines. Included activities incorporate coding, computer aided design, engineering drawings and 3D fabrication to produce innovative solutions for situations modeled after real life tissue engineering challenges. From designing and prototyping hydrogel wound coverings, to vascularization channels for organ on a chip applications, students learn to problem solve and think critically- skills that span way beyond the field of bioengineering.

       -    All inclusive
       -    Easy to use
       -    Satisfies Next Generation Science 
       -    Satisfies National Science Education Standards
       -    Hands on
       -    Real world applications
       -    Adaptable

Check out The Allevi Academy and learn how you can prepare students for the future of STEM and provide them with the tools they need to tackle the challenges of the future!

Print Alive, Print Allevi

Allevi Author: 3D Bioprinting a Spinal Cord

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People often ask us, “what is it that a bioprinter can do really well?”, and we tell them that it’s the ability to print and pattern living cells. Your cells are incredible organisms; they understand the environment around them and communicate with other cells to perform specific organ functions. This is why a bioprinter is such an amazing tool - it empowers you to control the geometry and placement of multiple cell types which allows cells to mimic the environments that they are used to in the body. But some cells are more finicky than others… induced pluripotent stem cells and neural cells for instance are difficult to keep alive and difficult to control.

That’s why this next #AlleviAuthor from University of Minnesota really blew us away with their new paper titled “3D Printed Stem-Cell Derived Neural Progenitors Generate Spinal Cord Scaffolds” and published in Advanced Functional Materials, wherein they used Allevi bioinks to 3D bioprint a spinal cord using induced pluripotent stem cells and oligodendrocyte progenitor cells (OPCs).

Successfully bioprinting multicellular neural tissue is a huge win for the field of regenerative medicine as it would allow damaged tissue to rebuild functional axonal connections across the central nervous system, essentially healing damaged connections. This technique will hopefully help develop new clinical approaches to treat neurological disease, such as spinal cord injury.

You can access the full paper here to learn more.