What the correction notice says
On 11 February 2026, Bioengineering published a formal correction (Birjandi and Sharpe 2026, Bioengineering 13(2):202, doi:10.3390/bioengineering13020202) to the 2025 paper “The Secretome of the Inductive Tooth Germ Exhibits Signals Required for Tooth Development” (Bioengineering 12(2):96), the source of this site’s 2026-08-31 analysis. The notice states that an error was identified in Figure 7, affecting panels D through I: the replacement microscopic images now correspond to the appropriate treatment conditions used in the study. The notice also states that the correction “does not affect the figure legend, the manuscript text, or the interpretation of the results” and that “the scientific conclusions of the study remain unchanged.” The Acknowledgments section was updated to thank Ana Angelova and Xuechen Zhang for support during the recombination experiments, and the notice records that the correction was approved by the Academic Editor and that the original publication has been updated in place (Birjandi and Sharpe 2026, Correction notice).
Why those panels matter
Figure 7 is the paper’s functional readout, not a peripheral measurement. Panels D through I hold the recombination-assay micrographs: the positive control pairing E14.5 inductive mesenchyme with E13.5 tooth germ epithelium, the negative control using non-inductive E10.5 branchial-arch mesenchyme, and the four test conditions in which epithelium pretreated with inductive small extracellular vesicles or secretome was recombined with the non-inductive mesenchyme. Every conclusion in the paper, and in this site’s August piece, about whether the cell-free preparations can substitute for living inductive mesenchyme rests on those six panels.
What changes for the record
The correction is about image provenance, not outcome. The stated result, that i-sEV-treated and i-secretome-treated epithelium failed to induce tooth formation when paired with non-inductive mesenchyme while the positive control formed tooth germs, stands as published, and both the authors and the handling editor explicitly affirm that the conclusions are unchanged. The August analysis said the same in its limitations section and its account of the functional test remains consistent with the corrected figure. Readers should nonetheless treat the corrected panels as the evidentiary basis going forward: the original micrographs for the core assay did not depict the conditions the legend described, which is a material documentation error even though the replacement images carry the same interpretation. For the bioengineered tooth germ program, the boundary the paper draws, that paracrine cargo can shift epithelial signaling but cannot replace inductive mesenchyme in this mouse reassociation assay, is unchanged by the correction.
Boundary of this note
This piece reports the publisher record only. It does not re-examine the raw recombination data, which are not published as source images beyond Figure 7, and it takes no position on how the mismatched images arose. If a further publisher action (for example an expression of concern or retraction) appears, this record will be updated with a dated note.
Provenance: grounded in the open-access correction notice Birjandi AA, Sharpe P. Correction: “The Secretome of the Inductive Tooth Germ Exhibits Signals Required for Tooth Development.” Bioengineering. 2026;13(2):202. doi:10.3390/bioengineering13020202, retrieved in full from the publisher. Method and sourcing standard at /method/.