3D Bioprinting for 3D Tissue Models

The 3D bioprinting techniques have been demonstrating the impressive achievements. However, the reconstruction precise tissue organ structures remain the challenges. For example, the integration of blood vessel into tissue organs for nutrient supply is not achievable. Therefore, it is expecting new technologies, which can well control define individual cells resolution to mimic reconstruction tissue organs. Light is appropriate method to accurately control individual objects and could help to reconstruct precise tissue organ structures. Here, we develop a new technique near infrared light (NIR) laser for printing and assembling building blocks such as cell-laden microgel, tissues forming desired patterns. The method allowed for high throughput as well as a high level of precision, thanks to the ability to control the laser spot size and direction.

Publications:

Journals:

1. '' Effective Light Directed Assembly of Building Blocks with Microscale Control'', Small, 2017, (Cover Feature)

Patents:

1. ''Methods of Assembling A Structure'', Patent filed, No. 10201701321V

Awards:

The work has been shortlisted (4 from ~600) for the Federation of Analytical Chemistry and Spectroscopy Societies (FACSS) innovation award.

Conferences:

1. Optofluidics, 2017

2. MicroTAS, 2017

Light-directed forces have been widely used to pattern micro/nanoscale objects with precise control, forming functional assemblies. However, a substantial laser intensity is required to generate sufficient optical gradient forces to move a small object in a certain direction, causing limited throughput for applications. In this study, we demonstrated a high-throughput light-directed assembly as a printing technology by introducing gold nanorods to induce thermal convection flows that move microparticles (diameter = 40 µm to several hundreds of micrometers) to specific light-guided locations, forming desired patterns. An automatic stage integrated with a light source was developed as a printing system to design the patterns with programmable manner. With the advantage of effective light-directed assembly, the microfluidic-fabricated monodispersed biocompatible microparticles were used as building blocks to construct a structured assembly (~10 cm scale) in ~2 min. The control with microscale precision was approached by changing the size of the laser light spot. After crosslinking assembly of building blocks, a novel soft material with wanted pattern was approached. To demonstrate its application, the mesenchymal stem-cell-seeded hydrogel microparticles were prepared as functional building blocks to construct scaffold-free tissues with desired structures. This light-directed fabrication method can be applied to integrate different building units, enabling the bottom-up formation of materials with precise control over their internal structure for bio-printing, tissue engineering, and advanced manufacturing.

3D Bioprinting (developing):