Methacrylic-based nanogels for the pH-sensitive delivery of 5-Fluorouracil in the colon

N Ashwanikumar,1,* Nisha Asok Kumar,2,* S Asha Nair,2 GS Vinod Kumar11Chemical Biology, 2Cancer Research Programme, Rajiv Gandhi Center for Biotechnology, Poojappura, Thiruvananthapuram, Kerala, India *These authors contributed equally to this workAbstract: Methacrylic-based copolymers in drug-delivery systems demonstrate a pH-sensitive drug-releasing behavior in the colon. In this study, copolymers of methacrylic acid and 2-ethyl hexyl acrylate were prepared using a microemulsion polymerization technique. The purified copolymer was characterized by Fourier transform infrared spectroscopy, proton nuclear magnetic resonance spectroscopy, and differential scanning calorimetry. 5-Fluorouracil (5-FU) was entrapped within methacrylic-based copolymers by a solvent evaporation method. The size of the nanogels formed was characterized by transmission electron microscopy and atomic force microscopy. In vitro drug-release studies using phosphate-buffered saline at different pH levels demonstrated the sustained release of 5-FU and its pH dependence. Cell proliferation assay of a human colon tumor colon cancer cell line (HCT-116) was performed and showed that the nanogels containing 5-FU exhibited considerable cytotoxicity in comparison with free 5-FU. Cell uptake of the nanogels was also monitored using confocal microscopy. Western blot analysis and flow cytometry studies confirmed that the nanogels could be successfully used as an efficient vector for pH-sensitive and controlled delivery of drugs specifically targeted to the colon.Keywords: 5-FU, methacrylic polymer, colon cancer, nanoge

Self-assembling peptide nanofibers containing phenylalanine for the controlled release of 5-fluorouracil

Narayanan Ashwanikumar,1 Nisha Asok Kumar,2 Padma S Saneesh Babu,2 Krishnankutty C Sivakumar,3 Mithun Varghese Vadakkan,1 Parvathi Nair,1 Ilamathi Hema Saranya,1 Sivakumari Asha Nair,2 Gopalakrishnapillai S Vinod Kumar1 1Chemical Biology, Nano Drug Delivery Systems, Bio-Innovation Center, 2Cancer Research Programme, 3Distributed Information Sub-Centre (Bioinformatics Centre), Rajiv Gandhi Centre for Biotechnology, Poojappura, Thiruvananthapuram, Kerala, India Abstract: The study shows that RADA-F6 peptide with pH-responsive self-assembling nature can be effectively used as a drug delivery system for the sustained release of a potent anticancer drug 5-fluorouracil (5-FU) at basic pH. As 5-FU contains the aromatic pyrimidine ring, RADA-F6 system is suitable for entrapping an aromatic drug due to effective π–π stacking with phenylalanine and be able to show better controlled release behavior. The stability and controlled release nature of RADA-F6 in different conditions followed by 5-FU entrapment at in silico conditions was confirmed by molecular dynamics simulation taking RADA-16 as control. Cytotoxicity of the drug-loaded RADA-F6 was measured by MTT assay and cellular uptake by confocal microscopy. Physicochemical characterization and further Western blot analysis and flow cytometric studies confirm that RADA-F6 can be successfully used as an efficient vector for pH-sensitive, controlled 5-FU delivery system. Keywords: scaffold, drug delivery, nanofibrous, aromati

Author Correction: Naturally-occurring cholesterol analogues in lipid nanoparticles induce polymorphic shape and enhance intracellular delivery of mRNA

An amendment to this paper has been published and can be accessed via a link at the top of the paper

Boosting Intracellular Delivery of Lipid Nanoparticle-Encapsulated mRNA

Intracellular delivery of mRNA holds great potential for vaccine− and therapeutic discovery and development. Despite increasing recognition of the utility of lipid-based nanoparticles (LNPs) for intracellular delivery of mRNA, particle engineering is hindered by insufficient understanding of endosomal escape, which is believed to be a main limiter of cytosolic availability and activity of the nucleic acid inside the cell. Using a series of CRISPR-based genetic perturbations of the lysosomal pathway, we have identified that late endosome/lysosome (LE/Ly) formation is essential for functional delivery of exogenously presented mRNA. Lysosomes provide a spatiotemporal hub to orchestrate mTOR signaling and are known to control cell proliferation, nutrient sensing, ribosomal biogenesis, and mRNA translation. Through modulation of the mTOR pathway we were able to enhance or inhibit LNP-mediated mRNA delivery. To further boost intracellular delivery of mRNA, we screened 212 bioactive lipid-like molecules that are either enriched in vesicular compartments or modulate cell signaling. Surprisingly, we have discovered that leukotriene-antagonists, clinically approved for treatment of asthma and other lung diseases, enhance intracellular mRNA delivery in vitro (over 3-fold, <i>p</i> < 0.005) and in vivo (over 2-fold, <i>p</i> < 0.005). Understanding LNP-mediated intracellular delivery will inspire the next generation of RNA therapeutics that have high potency and limited toxicity