A materials scientist is developing biodegradable hydrogels for tissue engineering scaffolds. The structural failure of one formulation, Alpha, during testing was hypothesized to be caused by an insufficient concentration of the cross-linking agent.
The table below shows the cross-linker concentration, CCC (in mmol/g\text{mmol/g}mmol/g), and the qualitative mechanical integrity status after 24 hours under physiological conditions for seven test formulations.
| Formulation | Cross-linker concentration (CCC / mmol/g\text{mmol/g}mmol/g) | Mechanical integrity status |
|---|---|---|
| Eta | 0.85 | Outstanding |
| Zeta | 0.68 | Highly stable |
| Epsilon | 0.52 | Stable |
| Delta | 0.31 | Unstable |
| Gamma | 0.24 | Stable |
| Beta | 0.12 | Highly unstable |
| Alpha | 0.05 | Collapsed |
Describe the evidence in the table that supports the hypothesis that a low cross-linker concentration contributed to the structural collapse of formulation Alpha.
Identify one piece of evidence from the table that does not support the hypothesis that a lower cross-linker concentration is directly correlated with a higher risk of mechanical instability.
