Researchers used bacterial retrons to build synthetic, non‑genetic DNA systems inside cells that bind specific proteins, creating programmable protein‑binding DNA constructs without altering the host genome. The approach produces small DNA molecules in situ that act as modular scaffolds for sequestering or reporting on protein activities, expanding the toolkit for intracellular synthetic biology. The technique could enable transient control of protein function, spatial reprogramming of cellular biochemistry, and new diagnostic or therapeutic constructs that avoid permanent genomic edits. Teams developing intracellular biologics and gene‑modulation platforms may adopt retron‑based systems where reversibility and minimal genomic perturbation are priorities.