Retraction Watch

Tracking retractions as a window into the scientific process

Drug paper gets a fix, notching several corrections

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rsc_tb_1_3_COVER.inddThe Journal of Materials Chemistry B has issued a laundry list of corrections for a 2014 chemotherapy paper, which address re-use of “some text”, incorrectly stated doses, and miscalculations of the drug concentration, among other issues.

The paper described a new way to deliver gemcitabine via nanoparticles, focusing the drug on the tumors.

It turns out the authors’ focus wasn’t so clear when writing the paper. The researchers, at the Chinese Academy of Medical Science, Peking Union Medical College, and Tianjin University in China, said they used “some text” from two 2013 papers by a team of French oncologists “without appropriate attribution,” as well as repeatedly getting the in vivo dose wrong. The manuscript also contained several incorrect calculations of the “drug loading,” or the proportion of active drug.

Here’s the correction for “Tailor-made gemcitabine prodrug nanoparticles from well-defined drug–polymer amphiphiles prepared by controlled living radical polymerization for cancer chemotherapy” (free, but requires sign-in):

The authors would like to acknowledge and apologise for using some text from references 1 and 2 (below) without appropriate attribution in some sentences from sections 3.1 and 3.6 and that Scheme 1 was redrawn from Scheme 1 in reference 2 without appropriate attribution. The authors would like to clarify that this work is not the first example of such an amphiphilic polymer and related work is cited in the manuscript.

The in vivo drug concentration dose is incorrectly stated as 26 mg kg1 throughout the manuscript (Abstract, sentence 8; section 2.8, paragraph 2, sentence 5; section 3.6, sentence 2; Discussion, paragraph 7, sentence 9). The correct dose administered was 0.693 mg mL1 obtained by concentrating the nanoparticle suspensions and the injection volume was 250 mL.

In several instances (section 3.1, paragraph 2, sentence 8; section 3.2, sentence 5; Table 1, column 7) the drug loading should be 30.4% and 17.7% for PMMA5 and PMMA11.2, rather than 43.7% and 21.5%, respectively. The drug loading in the manuscript had been calculated using the formula Gem/PM, rather than by the more accurate formula Gem/(Gem + PMMA).

The conclusions remain unchanged.


1 D. Trung Bui, A. Maksimenko, D. Desma¨ele, S. Harrisson, C. Vauthier, P. Couvreur and J. Nicolas, Biomacromolecules, 2013, 14, 2837–2847.

2 S. Harrisson, J. Nicolas, A. Maksimenko, D. T. Bui, J. Mougin and P. Couvreur, Angew. Chem., Int. Ed., 2013, 52, 1678–1682.

The Royal Society of Chemistry apologises for these errors and any consequent inconvenience to authors and readers.

The paper has been the subject of some discussion on PubPeer. We reached out to the journal to find out why they decided to correct instead of retract, and got a response from executive editor Fiona McKenzie that’s similar to some we’ve received from the Royal Society of Chemistry in the past:

The Correction was published in accordance to our Correction and Retraction guidelines (please see our website for further information). Full details of the Correction are in the Correction notice, which clearly states the updates required. Publication of this Correction is in line with Committee on Publication Ethics guidelines.

We’ve reached out to the author, and will update if we hear back.

Hat tip: Julien Nicolas

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