Table 4.
Engineered Solutions for Three-Dimensional Cell Culture
| Polymer name | Description | Example uses | Considerations |
|---|---|---|---|
| PLGA | A copolymer of lactic and glycolic acid, two monomers with different bond strengths. By changing the ratio of these two components, their hydrolysis rate can be tuned. PLGA has been used to form hard sponges at high densities and flexible hydrogels at low densities. | Electrospinning into filamentous scaffold, forming over dissolvable templates, crosslinking to form hydrogels259 | Intended as a robust initial matrix to be dissolved and wholly replaced over time. Used clinically in implants.260 |
| Poly (glycerol sebacate) | An engineered two-part polymer that has excellent biocompatibility and easily tunable degradation rates and stiffness. | Heart patches261 | Cells cannot be integrated into the scaffold during the formation process due to high temperatures and vacuum conditions. Cells must infiltrate into the scaffold postformation. |
| Photosetting hydrogels | PEGDA is an inert and biodegradable polymer that rapidly crosslinks when exposed to UV light and has been used to form 3D printed constructs through photolithographic printing.262,263 Other similar photosetting hydrogels exist.264,265 | Creation of vasculature in engineered cardiac tissue77 | The field of fabricating 3D printed biological constructs is rapidly evolving, so new and improved photosetting hydrogels are constantly being published. |
| PEG | A tunable biodegradable and largely inert polymer which is typically used for microscale tissue engineering, although it can be used as a surface treatment or used to fill up a more rigid scaffold. | High throughput microscale cardiac coculture with endothelial and fibroblasts for drug screening.266 PEG as a surface treatment.267 |
Typically used for 2D cell culture. |
| Modified biological hydrogels | Biological hydrogels improved using chemicals or postprocessing techniques. | Highly cross-linked collagen using a synthetic crosslinking compound.268 | Maintains physiological applicability of the base matrix, but with modified characteristics. |
2D, two-dimensional; PEG, polyethylene glycol; PEGDA, poly (ethylene glycol) diacrylate; PLGA, poly-lactic-glycolic-acid.