Bioprinting 101 – Part 15, Microarrays

Share this Article

DNA Microarray Setup

A DNA microarray can be referred to as a DNA chip or biochip. This technology refers to a collection of microscopic DNA spots attached to a solid surface. Scientists typically use microarrays to measure the expression levels of large numbers of genes simultaneously or to genotype multiple regions of a genome. So how is this technology relevant to bioprinting? We will go through this intriguing technology and how it affects bioprinting as a whole.

In terms of bioprinting, we must classify microarray bioprinting. Microarray bioprinting refers to printing cells encapsulated in hydrogels in a spatially addressable manner using automated liquid dispensing robots such as microarray spotters. An automated liquid dispensing robot refers to pipetting as well as pumping procedures done through machine automation. One can think of typical bioprinting setups with programmable syringe pumps. Microarray spotters refer to the robotic instruments used for making microarrays. This technology deposits (or “spots”) cDNA probes onto a microscope slide or other substrate. In genetics, complementary DNA (cDNA) is DNA synthesized from a single-stranded RNA (e.g., messenger RNA (mRNA) or microRNA) template in a reaction catalyzed by the enzyme reverse transcriptase. Cells are usually within the nanoliter volume (30 – 60nL) and can be dispensed onto functionalized glass slides or micropillar/microwell chip platforms. This is directly related to our previous article on DNA and how we talked about microfluidics. These cells can be grown in growth media to support miniaturized 3D cell cultures for toxicology assays. Toxicology assays are important in terms of bioprinting because one wants to make sure beforehand that the material being printed will not be detrimental or toxic to the body.

Microwell Chip and Extrusion setup

The microwell chip mentioned previously can accommodate up to 950 nL of compounds, recombinant viruses, growth factors, and fluorescent dyes for various cell-based assays. Since the micropillar chip is complementary to the microwell chip, cells on the micropillars can be exposed to hundreds of different test conditions in the microwells simultaneously by simply sandwiching the two chips together. The cells on the micropillar chip can be exposed to compounds for a period of time and stained with fluorescent dyes or fluorescently labeled antibodies to assess drug efficacy and toxicity. Compared to traditional 2D cell monolayer cultures, microarray bioprinting offers several attractive features, including physiologically relevant cells grown in 3D, miniaturization of cell-based assays saving valuable raw materials, such as primary human cells obtained from patients, and ultrahigh-throughput capability of testing cell culture conditions.

It is important to outline why physiologically relevant cell growth in 3D, miniaturization of cell-based assays, and ultrahigh-throughput capability of testing cell culture conditions are very important within microarray based bioprinting. In terms of microfluidics, the various cell structures in the human body must be vascularized to receive the nutrients and gas exchange help that they need to survive. Similarly, 3D cell cultures in vitro require certain levels of fluid circulation, which can be problematic for dense, 3D cultures where cells may not all have adequate exposure to nutrients. This is particularly important in hepatocyte cultures because the liver is a highly vascularized organ. Miniaturization of cell-based assays allows for rapid prototyping as well as low cost implementation within bioprinting processes. High-throughput screening (HTS) is a method for scientific experimentation especially used in drug discovery and relevant to the fields of biology and chemistry. Using robotics, data processing/control software, liquid handling devices, and sensitive detectors, high-throughput screening allows a researcher to quickly conduct millions of chemical, genetic, or pharmacological tests. Being able to do this in vitro allows us to feel more confident in the what is being used within the body in terms of bioprinting.

High Throughput Screening

Microarray bioprinting is a promising high-throughput approach for miniaturized 3D cell cultures. The reduction in sample volume and the speed of printing hundreds of samples in a short period of time make this technology suitable for wide ranges of cell-based assays. The biggest issue is learning how to control these microenvironments enabled by microarray bioprinting.

Share this Article


Recent News

Janne Kyttanen on Creativity in 3D Printing

What is Metrology Part 16: Introductory Coding



Categories

3D Design

3D Printed Art

3D Printed Food

3D Printed Guns


You May Also Like

What is Metrology Part 15: Inverse Filtering

This is an article on the essence of Inverse Filtering. Within this image processing method there are two distinct methods to deblur images.

What is Metrology Part 14: Image Restoration

This is an article detailing the depth of information and and knowledge within image restoration. Be prepared to take a brief trip on the extent of this technology and how it can be utilized.

What is Metrology Part 13: Object Recognition

This is an article focused on object recognition and how humans are doing such compared to computer systems. There is an attention to detail that humans have more then robots currently.

What is Metrology Part 12: 3D Reconstruction

In this article we are taking a closer look at 3D reconstruction. It is one of the many interesting fields to study under the lens of metrology and computer vision.


Shop

View our broad assortment of in house and third party products.


Print Services

Subscribe To Our Newsletter

Subscribe To Our Newsletter

Join our mailing list to receive the latest news and updates from our 3DPrint.com.

You have Successfully Subscribed!