Investigating 3R In Vivo Approaches for Bio‐Distribution and Efficacy Evaluation of Nucleic Acid Nanocarriers: Studies on Peptide‐Mimicking Ionizable Lipid

Abstract

Formulations based on ionizable amino‐lipids have been put into focus as nucleic acid delivery systems. Recently, the in vitro efficacy of the lipid formulation OH4:DOPE has been explored. However, in vitro performance of nanomedicines cannot correctly predict in vivo efficacy, thereby considerably limiting pre‐clinical translation. This is further exacerbated by limited access to mammalian models. The present work proposes to close this gap by investigating in vivo nucleic acid delivery within simpler models, but which still offers physiologically complex environments and also adheres to the 3R guidelines (replace/reduce/refine) to improve animal experiments. The efficacy of OH4:DOPE as a delivery system for nucleic acids is demonstrated using in vivo approaches. It is shown that the formulation is able to transfect complex tissues using the chicken chorioallantoic membrane model. The efficacy of DNA and mRNA lipoplexes is tested extensively in the zebra fish (Danio rerio) embryo which allows the screening of biodistribution and transfection efficiency. Effective transfection of blood vessel endothelial cells is seen, especially in the endocardium. Both model systems allow an efficacy screening according to the 3R guidelines bypassing the in vitro–in vivo gap. Pilot studies in mice are performed to correlate the efficacy of in vivo transfection.

PET imaging to assess fibroblast activation protein inhibitor biodistribution: A training program adapted to pharmacology education

“…Therefore, it is the goal of pharmacy teaching reform to replace animal experiments or reduce the use of laboratory animals with innovative experiments guided by the principle of the three R's (replacement, reduction, and refinement). 6 , 7 , 8 …”

“…This not only consumes large of experimental animals but also fails to provide an opportunity for visual observation of drug metabolism; thus, it is not conducive to the development of students' theoretical knowledge. Therefore, it is the goal of pharmacy teaching reform to replace animal experiments or reduce the use of laboratory animals with innovative experiments guided by the principle of the three R's (replacement, reduction, and refinement) 6–8 …”

“…Therefore, it is the goal of pharmacy teaching reform to replace animal experiments or reduce the use of laboratory animals with innovative experiments guided by the principle of the three R's (replacement, reduction, and refinement). [6][7][8] Positron emission tomography (PET) or PET with computed tomography (PET/CT) is a sensitive and rapidly emerging technology for in vivo imaging after labeling compounds capable of participating in metabolic processes with positron-emitting radionuclides (e.g., 18F, etc.). 9,10 PET imaging is widely used to obtain crucial pharmacokinetic information non-invasively and has developed rapidly on drug development recent years.…”