What they found
RADA16/EAK16 scaffolds support neuronal attachment, extensive neurite outgrowth (PC12, hippocampal, cerebellar, DRG neurons), and functional synapse formation comparable to Matrigel. First in vivo biocompatibility data: intramuscular injection in Fisher 344 rats (1 mg/ml, 20 μl) showed no inflammation, necrosis, motor impairment, or tissue abnormalities at 9 days to 5 weeks. Injection site was visually undetectable. No immune responses detected (rabbit/goat antibody assay). Scaffold pore size 50–200 nm, >99% water, macroscopic filament diameter 10–20 nm (consistent with Zhang 1993).
How this applies to h09
Biocompatibility data is directly relevant to the ototopical delivery route. The five stabilization mechanisms listed (H-bonds, ionic bonds, hydrophobic interactions, overlap, salt coordination) confirm that assembly depends on all four RADA units — truncation or charge disruption anywhere is likely to impair gelation, which is relevant to the 118 aa tail question. The “no immune response” data supports the scaffold as a safe delivery vehicle.
Key numbers
- Scaffold filament diameter (EM): 10–20 nm (bundle; consistent with Zhang 1993)
- Scaffold pore size: 50–200 nm
- In vivo biocompatibility: no inflammatory response, 9 days–5 weeks, rat IM injection
- Peptide assembly concentration: 1–10 mg/ml
- Cell types supporting growth: PC12, hippocampal, cerebellar granule, DRG, sympathetic neurons
Links
- PubMed: https://pubmed.ncbi.nlm.nih.gov/10841558/
- PMC: https://pmc.ncbi.nlm.nih.gov/articles/PMC18719/
- DOI: https://doi.org/10.1073/pnas.97.12.6728
Connections
- STRC Horizontal Top Connector Hydrogel Hypothesis — in vivo biocompatibility; no immune response
- STRC Phase 4d F-actin Bundling Model — supports safe delivery assumption
[see-also]1993-zhang-eak16-rada16-spontaneous-assembly — structural basis[see-also]2005-yokoi-kinoshita-zhang-rada16-reassembly — geometry follow-up