The dataset’s leading assignee holds 198 of the 2,064 records in scope, with the top five together accounting for 852 records, or 41.3% of the field. The ranking extends to 100 companies, so beyond the leaders the field fragments into a long tail of smaller filers. Because families rather than raw documents are the fairer comparison unit, this concentration reflects sustained research programmes rather than aggressive continuation filing alone.

Filings peaked at 128 in 2017 and, across the last window of complete years, fell from 98 in 2021 to 49 in 2024 — a -50% move. However, publication typically lags filing by about 18 months, so the lower counts shown for 2025 and 2026 in the raw trend are provisional and will rise as more records post. The 2021-2024 window is the most reliable evidence of an actual pullback.

This dataset is scoped specifically to polymeric nanoparticles, polyplex carriers and peptide carriers, distinct from lipid-based delivery systems, and filtered against practical formulation problems like buffering capacity, degradation rate, polymer toxicity, complexation ratio, colloidal stability and manufacturing consistency. The assignee base and claim language differ from lipid nanoparticle patent families, even where the two approaches compete for the same therapeutic applications. A carrier programme evaluating both routes should treat them as separate freedom-to-operate searches.