| Criteria | |||||
| Mechanism of detection | Access to cytosol | Calibration | Limit of detection | Endosomal escape | |
| Rationale | Justification | Validation | Translation | ||
| Data | Mentioned but not shown | Data provided but they do not support the conclusions | Lack of evidence that could support the conclusions | ||
| Figures | Values or units | Similarity | Duplication | Resolution | Label |
| Methodology | Materials preparation | Characterization | |||
| Characterization | DLS | TEM | |||
| Cell lines | Confluency | Lack of control | |||
| Use of scientific terms | Inaccurate | ||||
| References | Miscitation | No citation | Primary sources | Citation error |
Specification of the common issues
Articles lacking a discussion of endosomal escape
In the field of bionanoscience, several articles report the use of nanoparticles for intracellular sensing (viz. mRNAs, various ions, pH changes, and others). However, nanoparticles generally enter the cell by endocytosis. Many of those publications lack an explanation about the internalisation mechanism, and, crucially, endosomal escape. Indeed, to achieve the purpose of detection of cytosolic targets inside cells, the nanoparticles must escape the endosomes. In most articles that we have analysed so far this issue is ignored.
Here you can find a list of our comment on articles that report intracellular sensing with nanoparticles but do not discuss the endosomal escape of the nanomaterials.
Mechanisms of detection
Access to cytosol
The article claims the intracellular localisation of nanoparticles, but there is no mention of the mechanism of uptake through which the nanomaterials enter the cells.
Calibration
Lack of calibration or calibration that raises questions (e.g. binding equilibrium does not follow what would be expected from thermodynamics).
Limit of detection
LOD is not calculated; or the experiments or calculations raise questions.
Endosomal escape
There is no proof of nanomaterials endosomal escape.
Rationale
Justification
An explanation for justifying the necessity of the work is missing.
Validation
The data presented does not validate the claimed achievements or the methodology applied.
Translation
The work is presented as useful tool for certain purposes, e.g., diagnosis. However, the limitations for translating the methods “from the bench” to the application itself is not stated.
Data
Mentioned but not shown
Some techniques are mentioned in the methodology or results, but the data are not shown in the full text, nor in the supporting information.
Data provided but they do not support the conclusions
Lack of evidence that could support the conclusions
Figures
Values or units
The units or values of X-axis and Y-axis are not shown.
The values in the axis do not match the ticks.
Similarity
Data from different samples or conditions are more similar than would be expected.
Duplication
Image duplication for different conditions detected within the article or across publications.
Magnification and resolution
The magnification or resolution is too low to draw conclusions, e.g. on precise intracellular localisation of nanoparticles.
Label
Errors in the text of the labels or confusing definitions.
Methodology
Materials preparation
Reproducing the experiments would be difficult because specifications are missing regarding the preparation or procurement of materials.
Characterization
Characterization of materials is incomplete or lacking.
Nanoparticles size
DLS
When claiming the nanoparticles hydrodynamic diameter, for more precise conclusions we suggest the following issues to be corrected:
-
- The size distribution is not shown.
- The average size of multimodal data is reported. In such cases, the discussion should make clear that different size populations were observed, and state the average of each population, not of the sample.
- It is not clear whether the distribution represents the intensity of light, number or volume of particles. (For more precise claiming of the nanomaterials size, this should be indicated, because many times only one population of particles is seen in the number or volume data, but actually the intensity shows a multimodal distribution. Further, number and volume can only be considered when the quality of the data are adequate, which means good correlation function and low PdI. For more information, please check Intensity-Volume-Number: Which size is correct?. Please note this comes from a company, and additional references will be provided as soon as possible).
TEM
The physical size is given, but the distribution is not provided and there is no detail about the statistics.
The physical size is given but only a few nanoparticles can be seen in the micrographs.
The stability of the nanomaterials is claimed but aggregates are present in the micrographs.
Cell lines
Lack of control
Control experiments are missing, for example, to prove specificity or demonstrate lack of toxicity.
Use of scientific terms
Inaccurate
Established terms used in a different way from their normal use.
Replacing established terms in the literature by confusing definitions.
Overstatement
An exaggeration of the claims, results and relevance of the work is made without being adequately justified, usually supported by words as ‘exceptional’, ‘the best material’, ‘we report a new method’, ‘high sensitivity’, ‘significant enhancement’, and others.
References
Miscitation
The citation is not related to or does not support the claim. In some cases the citation supports an idea or fact opposite to what it is stated in the publication we are analysing.
No citation
An important claim is made mentioning sentences as “previous works” or “it is discussed” but no reference is cited at the end of the sentence.
Primary sources
Reviews or other secondary sources are cited instead of the original work.
Citation error
The cited work is from an author different from the one mentioned in the text.
Other remarks
The concerns which are not classified in the grid, but still relevant according to us.
