Bottom-up approach to fabricate 3D-vascularized tissue construct

Rationals:

In our previous work, we achieved directed assembly of microengineered microgels with different shapes (rectangular and lock-and-key) into 3D tissue construct with pre-defined architectures (Du et al. PNAS 2008). Despite the control we have gained in the final geometries, the arrangement of the different microgel building blocks is still random. In order to engineer biomimetic tissue constructs with complex geometry (i.e. bifurcated vascularized tissue) and heterogeneous properties (i.e. different cell types), microgels with different shapes and properties should be incorporated synergistically into the final modular assembly. Therefore, novel assembly approaches are required to achieve the spatially-controlled assembly of different microgels with heterogeneous properties (geometries and chemical/biological components). Here we propose a directed assembly approach to achieve spatially-controlled assembly of the microgel building blocks by sequentially assembling. This approach allows the in vitro creation of cell-laden tissue constructs that closely mimic blood vessels.

Plans:

Fig 1. Schematic of the sequential assembly procedure;(Done)

Fig 2. Optimization of the several parameters (thickness of hydrogel, speed of the needle, effects of surfactant, space between hydrogel, size of hydrogel)of the sequential assembly using one-hole design; (Done)

Fig 3. Build 3D bifurcated microfluidic system: test the flow properties by perfusing dyes inside the 3D microfluidic system after secondary-crosslinking to stabilize the structure, diffusion of dye with time (In progress)

Fig 4. Fabrication of vascularized 3D tissue structures (with endothelial cells and functional cells) (in progress)

Fig 5. Test the tissue performance of the 3D vascularized tissue construct under perfusion (viability, proliferation) (planning);