Ammonium glycyrrhizinate-loaded niosomes as a potential nanotherapeutic system for anti-inflammatory activity in murine models
Authors: Michelangelo Iannone
Maria Carafa
Massimo Fresta
Carlotta Marianecci
Marica Mastriota
Donatella Paolino
Christian Celia
Luisa Di Marzio
Stefano Pieretti
Federica Rinaldi
Journal: International Journal of Nanomedicine (2014)
Discipline: PHARMACOLOGY & TOXICOLOGY
Keywords: ammonium glycyrrhizinate; cytotoxicity; inflammation; niosomes; pH sensitivity.
Affiliations: Department of Drug Chemistry and Technologies, University Sapienza of Rome, Rome, Italy., Department of Pharmacy, University G d'Annunzio of Chieti of Pescara, Chieti, Italy., Department of Therapeutic Research and Medicine Evaluation, Istituto Superiore di Sanità, Rome, Italy., Department of Pharmacy, University G d'Annunzio of Chieti of Pescara, Chieti, Italy ; Department of Nanomedicine, The Methodist Hospital Research Institute, Houston, TX, USA., Department of Health Sciences, University Magna Graecia of Catanzaro, University Campus S Venuta, Building of BioSciences, Germaneto, Italy., ARPA Calabria, Environmental Epidemiology Center, Italy ; CNR, Neuroscience Institute, Pharmacology Section, Complesso "Nini Barbieri", Roccelletta di Borgia, Italy.

Abstract:  Background: Liquorice extracts demonstrate therapeutic efficacy in treating dermatitis, eczema, and psoriasis when compared with corticosteroids. In this work, nonionic surfactant vesicles (niosomes, NSVs) containing polysorbate 20 (Tween 20), cholesterol, and cholesteryl hemisuccinate at different molar concentrations were used to prepare monoammonium glycyrrhizinate (AG)-loaded NSVs. The anti-inflammatory properties of AG-loaded NSVs were investigated in murine models. Methods: The physicochemical properties of the NSVs were characterized using dynamic light scattering. The fluidity of the lipid bilayer was evaluated by measuring the fluorescence intensity of diphenylhexatriene. The drug entrapment efficiency of AG was assessed using high-performance liquid chromatography. The physicochemical stability of the NSVs was evaluated as a function of time using dynamic light scattering combined with Turbiscan Lab Expert analysis. Serum stability was determined by incubating the NSVs with 10% v/v fetal bovine serum. The cytotoxic effects of the NSVs were investigated in human dermal fibroblasts using the Trypan blue dye exclusion assay (for cell mortality) and an MTT assay (for cell viability). Release profiles for the AG-loaded NSVs were studied in vitro using cellulose membranes. NSVs showing the most desirable physicochemical properties were selected to test for in vivo anti-inflammatory activity in murine models. The anti-inflammatory activity of the NSVs was investigated by measuring edema and nociception in mice stimulated with chemical agents. Results: NSVs showed favorable physicochemical properties for in vitro and in vivo administration. In addition, they demonstrated long-term stability based on Turbiscan Lab Expert analysis. The membrane fluidity of the NSVs was not affected by self-assembling of the surfactants into colloidal structures. Fluorescence anisotropy was found to be independent of the molar ratios of cholesteryl hemisuccinate and/or cholesterol during preparation of the NSVs. The anti-inflammatory AG drug showed no effect on the stability of the NSVs. In vivo experiments demonstrated that AG-loaded NSVs decreased edema and nociceptive responses when compared with AG alone and empty NSVs. In vitro and in vivo results demonstrated that pH sensitive and neutral NSVs show no statistical significant difference. Conclusion: NSVs were nontoxic and showed features favorable for potential administration in vivo. In addition, neutral NSVs showed signs of increased anti-inflammatory and antinociceptive responses when compared with AG. 

Retracted: No

PubPeer comments:
 image duplication ![file] Disclaimer: These potential image duplications have been detected automatically using ImageTwin http: dx.doi.org 10.1145 3019612.3019875 Although results have been curated, the automatic algorithm may have generated false positive results and cannot take into account all scientific explanations for apparent duplications like stripped and reprobed blots, time series, serial sections and reused controls. , 
 #1 I agree and have indicated another overlap in red. The PubPeer system seems to have gotten the last two authorsu2019 names confused. *** ![file] , 
 Retracted [3 August 2022] . ------------------------ The Editor and Publisher of International Journal of Nanomedicine wish to retract the published article. Concerns were raised regarding the alleged duplication of TEM images in Figure 1. Specifically, - Figure 1A, F1, appears to have been duplicated with the same image for Figure 1C, F3 and Figure 1D, F3AG. The authors did respond to our queries but were unable to explain how the duplication of images occurred, nor were they able to provide the original TEM images from the reported study. The decision was made to retract the article and the authors were notified of this. Our decision-making was informed by our policy on publishing ethics and integrity and the COPE guidelines on retraction. The retracted article will remain online to maintain the scholarly record, but it will be digitally watermarked on each page as u201cRetractedu201d. , 
 #3 The freeze-fracture transmission electron microscopy analyses were performed 9 years ago by an external laboratory (article Received 27 September 2013). The lab was closed in 2015, the cryo-TEM apparatus is no more in use and our collaboration ended in 2014. The researcher who performed the experiment retired. As our publications can confirm there are no more cryo-TEM images of our samples published after 2015. We started new collaborations to collect TEM and AFM images. For all these reasons, it was impossible to retrieve original TEM images collected for Figure 1. We found after a long and complex research some unpublished images of the same samples described in the article and stored in an old CD. They come from the original published study and are provided to the Editor. The date of the image files are the extraction date of the files from the CD. We are sure it was an unintentional error of that occurred during the assembly of the Figure. We regret that in Fig 1, maybe due to a technical error in exporting images from the microscope, a part of the images are duplicated. We are really sorry for this and we hope you will trust us. We didnu2019t mean to alter data or to publish false images. If so, we would have falsified images in a perfect way. In the article the presence of niosomes in our samples was confirmed by 3 different technique: DLS, Turbiscanu00ae Lab expert and Fluorescence analysis. Furthermore, we can also assure that the experiment in question had no influence or impact on the major conclusions of the article: Ammonium glycyrrhizinate-loaded niosomes containing Tween 20 cholesterol improve the anti-inflammatory activity and antinociceptive effects of AG in comparison with the free drug in a murine animal model. We ask to the Editor to retire only Figure 1 because the error was unintentional and all other results did not depend by TEM images. The Editor and the referee verified the quality of our results before pubblication. This article collected 41 citations meaning a wide interest in our research and in our results, despite the unintentional error in Figure 1. Furthermore, it is classified in the journal website as u201chighly accessedu201d The authors confirm that it is not a malicious error but only negligent, which does not change the conclusions of our experimental investigation. We ask Editor to trust us and allow us to modify Figure 1 using the recovered images. Editor unwavering judgment can cause reputational damage to the authors and the institutions they represent. , 
 #4 I thank the author for providing the editorial background. I understand the author s frustration, however the possibility of an error during figure assembly does not appear to explain all of the issues that are illustrated in #2. Nor would a technical error when exporting the images from the microscope. Both of the areas outlined (the green ones and the red ones) have different aspect ratios. These seem to have been stretched disproportionally to each other while the scale bars indicates the scale is the same for all three images involved (which would be expected). This suggests that someone resized the images without concern about preserving the image dimensions or size. It is hard to believe that a researcher would think it OK to alter images in this fashion during figure assembly. ,