Over the past decade there has been an exponential increase in the number of research papers utlising nanoparticles for biological applications such as intracellular sensing [1, 2], theranostics [3-5] and more recently drug delivery and precision medicine [6, 7]. Despite the success stories, there is a disconnect regarding current dogma on issues such as nanoparticle uptake and trafficking, nanoparticle delivery via the enhanced permeability and retention (EPR) effect, and endosomal escape. Critical re-evaluation of these concepts both conceptually and experimentally is needed for continued advancement in the field.

 

For this preregistration, Said et al. (2024) focus on nanoparticle intracellular trafficking, specifically endosomal escape [8]. The current consensus in the literature is that nanoparticles enter cells via endocytosis [9, 10] but reportedly just 1-2% of nanoparticles/ nanoparticle probes escape endosomes and enter the cytoplasm [11-13]. There is therefore an apparent paradox over how sensing nanoparticles can detect their intended targets in the cytoplasm if they are trapped within the cell endosomes. To address this fundamental issue of nanoparticle endosomal escape, Lévy and coworkers are carrying out replication studies to thoroughly and transparently replicate the most influential papers in the field of nanoparticle sensing. The aim of these replication studies is twofold: to establish a robust methodology to study endosomal escape of nanoparticles, and to encourage discussions, transparency and a step-change in the field.  

 

 

For this replication study, the authors classified papers on the topic of nanoparticle sensing and subsequently ranked them by number of citations.  Based on this evaluation they selected a paper by Zhu and colleagues [14] entitled “Carbon-Dot-Based Dual-Emission Nanohybrid Produces a Ratiometric Fluorescent Sensor for In Vivo Imaging of Cellular Copper Ions” for their seminal replication study.  To determine the reproducibility of the results from Zhu et al., the authors aim to establish the proportion of endosomal escape of the nanoparticles, and to examine the data in a biological context relevant to the application of the probe.

 

 

The authors plan to replicate the exact conditions reported in the materials and methods section of the selected paper such as nanoparticle probe synthesis of CdSe@C-TPEA nanoparticles, assessment of particle size, stability and reactivity and effect on cells (TEM, pH experiments, fluorescent responsivity to metal ions and cell viability). In addition, Said et al., plan to include further experimental characterisation to complement the existing study by Zhu and colleagues. They will incorporate additional controls and methodology to determine the intracellular location of nanoparticle probes in cells including: quantifying excess fluorescence in the culture medium, live cell imaging analysis, immunofluorescence with endosomal and lysosomal markers, and electron microscopy of cell sections. The authors will also include supplementary viability studies to assess the impact of the nanoparticles on HeLa cells as well as an additional biologically relevant cell line (for use in conjunction with the HeLa cells as per the original paper).

 

The Stage 1 manuscript underwent two rounds of thorough in-depth review. After considering the detailed responses to the reviewers' comments, the recommenders  determined that the manuscript met the Stage 1 criteria and awarded in-principle acceptance (IPA).  

 

The authors have thoughtfully considered their experimental approach to the replication study, whilst acknowledging any potential limitations. Given that conducting such a replication study is novel in the field of Nanotechnology and there is currently no ‘gold standard’ approach in doing so, the authors have showed thoughtful regard of statistical analysis and unbiased methodology where possible.

 

Based on current information, this study is the first use of preregistration via Peer Community in Registered Reports and the first formalised replication study in Nanotechnology for Biosciences. The outcomes of this of this study will be significant both scientifically and in the wider context in discussion of the scientific method.

 

 
Level of bias control achieved: Level 6. No part of the data or evidence that will be used to answer the research question yet exists and no part will be generated until after IPA.
 
List of eligible PCI RR-friendly Journals:

 

 

1. Howes, P. D., Chandrawati, R., & Stevens, M. M. (2014). Colloidal nanoparticles as advanced biological sensors. Science, 346(6205), 1247390. https://doi.org/10.1126/science.1247390

 

2. Liu, C. G., Han, Y. H., Kankala, R. K., Wang, S. B., & Chen, A. Z. (2020). Subcellular performance of nanoparticles in cancer therapy. International Journal of Nanomedicine, 675-704. https://doi.org/10.2147/IJN.S226186

 

3. Tang, W., Fan, W., Lau, J., Deng, L., Shen, Z., & Chen, X. (2019). Emerging blood–brain-barrier-crossing nanotechnology for brain cancer theranostics. Chemical Society Reviews, 48(11), 2967-3014. https://doi.org/10.1039/C8CS00805A

 

4. Yoon, Y. I., Pang, X., Jung, S., Zhang, G., Kong, M., Liu, G., & Chen, X. (2018). Smart gold nanoparticle-stabilized ultrasound microbubbles as cancer theranostics. Journal of Materials Chemistry B, 6(20), 3235-3239. https://doi.org/10.1039%2FC8TB00368H

 

5. Lin, H., Chen, Y., & Shi, J. (2018). Nanoparticle-triggered in situ catalytic chemical reactions for tumour-specific therapy. Chemical Society Reviews, 47(6), 1938-1958. https://doi.org/10.1039/C7CS00471K

 

6. Hou, X., Zaks, T., Langer, R., & Dong, Y. (2021). Lipid nanoparticles for mRNA delivery. Nature Reviews Materials, 6(12), 1078-1094. https://doi.org/10.1038/s41578-021-00358-0

 

7. Mitchell, M. J., Billingsley, M. M., Haley, R. M., Wechsler, M. E., Peppas, N. A., & Langer, R. (2021). Engineering precision nanoparticles for drug delivery. Nature Reviews Drug Discovery, 20(2), 101-124. https://doi.org/10.1038/s41573-020-0090-8

 

8. Said, M., Gharib, M., Zrig, S., & Lévy, R. (2024). Replication of “Carbon-Dot-Based Dual-Emission Nanohybrid Produces a Ratiometric Fluorescent Sensor for In Vivo Imaging of Cellular Copper Ions”. In principle acceptance of Version 3 by Peer Community in Registered Reports. https://osf.io/qbxpf

 

9. Behzadi, S., Serpooshan, V., Tao, W., Hamaly, M. A., Alkawareek, M. Y., Dreaden, E. C., ... & Mahmoudi, M. (2017). Cellular uptake of nanoparticles: Journey inside the cell. Chemical Society Reviews, 46(14), 4218-4244. https://doi.org/10.1039/C6CS00636A

 

10. de Almeida, M. S., Susnik, E., Drasler, B., Taladriz-Blanco, P., Petri-Fink, A., & Rothen-Rutishauser, B. (2021). Understanding nanoparticle endocytosis to improve targeting strategies in nanomedicine. Chemical society reviews, 50(9), 5397-5434. https://doi.org/10.1039/D0CS01127D

 

11. Smith, S. A., Selby, L. I., Johnston, A. P., & Such, G. K. (2018). The endosomal escape of nanoparticles: toward more efficient cellular delivery. Bioconjugate Chemistry, 30(2), 263-272. http://dx.doi.org/10.1021/acs.bioconjchem.8b00732

 

12. Cupic, K. I., Rennick, J. J., Johnston, A. P., & Such, G. K. (2019). Controlling endosomal escape using nanoparticle composition: current progress and future perspectives. Nanomedicine, 14(2), 215-223. https://doi.org/10.2217/nnm-2018-0326

 

13. Wang, Y., & Huang, L. (2013). A window onto siRNA delivery. Nature Biotechnology, 31(7), 611-612. https://doi.org/10.1038/nbt.2634

 

14. Zhu, A., Qu, Q., Shao, X., Kong, B., & Tian, Y. (2012). Carbon-dot-based dual-emission nanohybrid produces a ratiometric fluorescent sensor for in vivo imaging of cellular copper ions. Angewandte Chemie (International ed. in English), 51(29), 7185-7189. https://doi.org/10.1002/anie.201109089

Rapid learning in response to pain is a crucial survival mechanism, relying on forming associations between cues in the environment and subsequent pain or injury. Existing evidence suggests that associations between conditioned stimuli (cues) and unconditioned aversive stimuli (such as pain) are learned faster than for appetitive stimuli that signal pain relief. In addition, when the link between a conditioned and unconditioned stimulus is broken (by unpairing them), the extinction of this learning effect is slower for aversive that appetitive stimuli, resulting in a flatter extinction slope. Understanding why extinction slopes are reduced for aversive stimuli is important for advancing theoretical models of learning, and for devising ways of increasing the slope (and thus facilitating extinction learning) could help develop more effective methods of pain relief, particularly in the treatment of chronic pain.

 

In the current programmatic submission, Busch et al. (2023) will undertake two Registered Reports to test whether a verbal instruction intervention that explicitly informs participants about contingency changes between conditioned and unconditioned stimuli facilitates extinction learning, especially for aversive (painful) stimuli, and how changes in extinction learning relate to neural biomarkers of functional connectivity. In the first Registered Report, they will initially seek to replicate previous findings including faster acquisition of aversive than appetitive conditioned stimuli as well as incomplete extinction of aversive conditioned stimuli without verbal instruction. They will then test how the instruction intervention alters extinction slopes and the completeness of extinction for appetitive and aversive stimuli, using a range of behavioral measures (expectancy and valence ratings) and physiological measures (pupillometry, skin conductance responses). To shed light on the neural correlates of these processes, in the second Registered Report the authors will use functional magnetic resonance imaging (fMRI) to ask firstly how acquisition and extinction of aversive and appetitive conditioned responses are related to resting state brain connectivity within a network that includes ventromedial prefrontal cortex, amygdala, and striatum, and secondly, whether the effectiveness of instruction on extinction learning is associated with differences in resting state connectivity across this network.

 

The Stage 1 manuscript was evaluated over two rounds of in-depth review. Based on detailed responses to the reviewers' comments, the recommender judged that the manuscript met the Stage 1 criteria and therefore awarded in-principle acceptance (IPA).

 

URL to the preregistered Stage 1 protocol: https://osf.io/cj75p (under temporary private embargo)
 
Level of bias control achieved: Level 6. No part of the data or evidence that will be used to answer the research question yet exists and no part will be generated until after IPA.
 
List of eligible PCI RR-friendly journals:
 

 

1. Busch, L., Wiech, K., Gamer, M., Knicses, B., Spisak, T., Schmidt, K., & Bingel, U. (2023). Modulatory effects of instructions on extinction efficacy in appetitive and aversive learning: A registered report. In principle acceptance of Version 3 by Peer Community in Registered Reports. https://osf.io/cj75p

Recent studies have revealed potential benefits of unconditional cash transfers (UCTs) on a variety of health and social outcomes, including self-reported happiness and life satisfaction (Haushofer & Shapiro, 2016), economic and financial well-being (Blattman et al., 2013; Baird et al., 2018) and educational attainment (Baird et al., 2016). Although the effects of UCTs do not always out-perform rigorous control conditions (Whillans & West, 2022), these findings prompt the question of whether the alleviation of poverty via UCTs can also influence cognitive processing and performance.

 

In the current study, Szaszi et al. analysed the results of a previous randomised trial of UCTs by Blattman et al. (2017) to test whether a $200 lump sum – equivalent to three months of income – administered to a sample of young men in Liberia carries both short- and long-term benefits for a range of executive functions, including attention, response inhibition, and working memory capacity. Overall, the results suggest minimal if any consequences of the intervention – the observed effects of UCTs on cognition were several times smaller than suggested by previous research, and the evidence for a positive effect was inconclusive. Extensive multiverse analyses showed that these findings were robust to a range of alternative analytical specifications, and the authors estimate that a sample size of nearly 5000 would be required to provide strong evidence.

 

In their Discussion, the authors explore a range of reasons for the negative findings compared with previous research, including the more rigorous and severe causal test enabled by the randomised trial design, the demographic homogeneity of the sample demographic, the use of pen-and-paper tests (cf. computerised tests in previous studies), and the delivery of a lump-sum cash transfer compared with a regular monthly installment. In addition, although the results were negative or inconclusive, there were hints that a positive effect of UCTs may be more evident in some cognitive domains than in others – in this case, potentially benefiting working memory more than inhibitory control. Further research would be required to confirm this hypothesis.

 

The Stage 2 manuscript was evaluated over one round of in-depth review. Based on the responses to the reviewers' comments, the recommender judged that the manuscript met the Stage 2 criteria and awarded a positive recommendation.

 

URL to the preregistered Stage 1 protocol: https://osf.io/k56yv

 

Level of bias control achieved: Level 2. At least some data/evidence that was used to answer the research question had been accessed and partially observed by the authors prior to Stage 1 acceptance, but the authors certified that they had not yet observed the key variables within the data that would be used to answer the research question AND they took additional steps to maximise bias control and rigour.

 

 

 

 

1. Haushofer, J. & Shapiro, J.  (2016). The short-term impact of unconditional cash transfers to the poor: Experimental evidence from Kenya. Quarterly Journal of Economics, 13, 1973–2042. https://doi.org/10.1093/qje/qjw025

 

2. Blattman, C., Fiala, N. & Martinez, S. (2013) Generating skilled self-employment in developing countries: Experimental evidence from Uganda. Quarterly Journal of Economics, 129, 697–752. https://doi.org/10.1093/qje/qjt057

 

3. Baird, S., McKenzie, D., & Özler, B. (2018). The effects of cash transfers on adult labor market outcomes. IZA Journal of Development and Migration, 8, 1-20. https://doi.org/10.1186/s40176-018-0131-9

 

4. Baird, S., Chirwa, E., De Hoop, J., & Özler, B. (2016). Girl power: cash transfers and adolescent welfare: evidence from a cluster-randomized experiment in Malawi. In African Successes, Volume II: Human Capital (pp. 139-164). University of Chicago Press. https://www.nber.org/system/files/chapters/c13380/c13380.pdf

 

5. Whillans, A., & West, C. (2022). Alleviating time poverty among the working poor: A pre-registered longitudinal field experiment. Scientific Reports, 12(1), 1-17. https://doi.org/10.1038/s41598-021-04352-y

 

6. Blattman, C., Jamison, J. C. & Sheridan, M. (2017). Reducing crime and violence: Experimental evidence from cognitive behavioral therapy in Liberia. American Economic Review, 107, 1165–1206. http://doi.org/10.1257/aer.20150503

 

7. Szaszi, B., Palfi, B., Neszveda, G., Taka, A., Szecsi, P., Blattman, C., Jamison, J. C., & Sheridan, M. (2022). Does alleviating poverty increase cognitive performance? Short- and long-term evidence from a randomized controlled trial. Stage 2 Registered Report, acceptance of Version 2 by Peer Community in Registered Reports. https://psyarxiv.com/4gyzh

Cerebral small vessel disease (CSVD) is a common and multi-faceted set of pathologies that affect the small arteries, arterioles, venules and capillaries of the brain. The disease manifests through a range of symptoms and conditions, including psychiatric disorders, abnormal gait, and urinary incontinence, while accounting for 25% of strokes and nearly 50% of dementia.

 

The presence of CSVD is associated with white matter lesions detected as white matter hyperintensities (WMH) using neuroimaging, which have in turn been shown to predict future stroke, cognitive decline and dementia. While vascular risk factors of CSVD (such as hypertension and obesity) are also associated with CSVD, a complete picture of the predictive relationship between WMH, cognitive decline, and blood pressure remains to be determined, as does the role of sex/gender. These inter-relationships are important to determine for improving the diagnosis and treatment of CSVD.

 

In the current study, Beyer et al. analysed a large emerging dataset from the LIFE-Adult project – a longitudinal, two-wave, population-based study – to ask whether higher blood pressure predicts a greater increase in WMH, and whether progression of WMH is associated with measures of memory and executive function. In addition, the authors explored the relationship between abdominal obesity and WMH progression, and the extent to which WMH progression, and its interaction with vascular risk factors, depends on sex/gender.

 

Results revealed no reliable association between baseline blood pressure with WMH progression. WMH progression significantly predicted global cognitive decline but not decline in executive function specifically. Exploratory analyses revealed that increases in diastolic blood pressure as well as baseline and systolic blood pressure were associated with WMH progression, specifically in frontal periventricular regions, but there was no association of waist-to-hip ratio (a proxy of abdominal fat deposits) with WMH progression nor any gender-specific associations. The authors conclude that strict control of blood pressure might confer a protective effect, limiting WMH progression and negative effects on global cognitive function in the middle-aged to older population.

 

The Stage 2 manuscript was evaluated over one round of in-depth review. Based on responses to the reviewer's comments, the recommender judged that the manuscript met the Stage 2 criteria and awarded a positive recommendation.
 
URL to the preregistered Stage 1 protocol: https://osf.io/qkbgj

 

Level of bias control achieved: Level 2. At least some data/evidence that was used to answer the research question had been accessed and partially observed by the authors prior to Stage 1 in-principle acceptance, but the authors certify that they had not yet observed the key variables within the data that were used to answer the research question.

 
List of eligible PCI RR-friendly journals:

 

• Brain and Neuroscience Advances
• Cortex
• F1000Research
• Imaging Neuroscience
• In&Vertebrates
• NeuroImage: Reports
• Peer Community Journal
• PeerJ
• Royal Society Open Science
   

 

 

1. Beyer, F., Lammer, L., Loeffler, M., Riedel-Heller, S., Debette, S., Villringer, A. & Witte, A. V. (2023). Progression of white matter hyperintensities is related to blood pressure increases and global cognitive decline – a registered report [Stage 2]. Acceptance of Version 2 by Peer Community in Registered Reports. https://osf.io/k24pm

A poor diet has severe detrimental health effects, and attempts to reduce caloric intake often prove unsuccessful. Unhealthy foods, high in fat, sugar, and salt tend to be highly appetitive, and can undermine individuals’ ability to refrain themselves from consuming them. Computerized cognitive retraining techniques have shown promise in curbing the intake of unhealthy foods and promoting weight loss. However, in real-world scenarios, adherence to such retraining programs can be suboptimal, potentially diminishing their effectiveness.

 

In the present study, Maclellan et al. (2024) aimed to investigate whether the incorporation of gamified elements, transforming the cognitive retraining task into a game-like experience, can enhance adherence and overall intervention effectiveness by boosting engagement and motivation.

 

Upon testing the main hypotheses, the authors found mostly non-significant effects of adding gamified elements to adherence, motivation, or effectiveness of food response inhibition training programs. These results hold high relevance, as indeed there has been a push in introducing gamified elements to cognitive retraining programs. These findings should guide future developments in the field of cognitive retraining.

 

The Stage 2 manuscript was evaluated over one round of review and revision. Based on detailed evaluations by two expert reviewers, the recommender judged that the manuscript met the Stage 2 criteria and awarded a positive recommendation.

 

Level of bias control achieved: Level 6. No part of the data or evidence that was used to answer the research question was generated until after IPA.
 
List of eligible PCI RR-friendly journals:
 

• Addiction Research & Theory
• Advances in Cognitive Psychology
• Collabra: Psychology
• Journal of Cognition
• Peer Community Journal
• PeerJ
• Royal Society Open Science
• Studia Psychologica
• Swiss Psychology Open
   

 

MacLellan, A., Pennington, C. R., Lawrence, N., Westwood, S. J., Jones, A., Slegrova, A., Sung, B., Parker, L., Relph, L., Miranda, J. O., Shakeel, M., Mouka, E., Lovejoy, C., Chung, C., Lash, S., Suhail, Y., Nag M., and Button​, K. S. (2024). The effects of isolated game elements on adherence rates in food response inhibition training​ [Stage 2]. Acceptance of Version 3 by Peer Community in Registered Reports.