Oral Gene Delivery with cyclo-(d-Trp-Tyr) Peptide Nanotubes

Abstract

The feasibility of cyclo-(D-Trp-Tyr) peptide nanotubes (PNTs) as oral gene delivery carriers was investigated in nude mice with eight 40 μg doses of pCMV-lacZ in 2 days at 3 h intervals. The association between DNA and PNTs, the DNase I stability of PNTs-associated DNA, and in vitro permeability of DNA were estimated. The results showed that the cyclo-(D-Trp-Tyr) PNTs self-associated at concentrations above 0.01 mg/mL. Plasmid DNA associated with PNTs with a binding constant of 3.2 × 10 8 M −1 calculated by a fluorescence quenching assay. PNTs were able to protect DNA from DNase I, acid, and bile digestion for 50 min, 60 min, and 180 min, respectively. The in vitro duodenal apparent permeability coefficient of pCMV-lacZ calculated from a steady state flux was increased from 49.2 ± 21.6 × 10 −10 cm/s of naked DNA to 395.6 ± 142.2 × 10 −10 cm/s of pCMV-lacZ/PNT formulation. The permeation of pCMV-lacZ formulated with PNTs was found in an energy-dependent process. Furthermore, β-galatosidase (β-Gal) activity in tissues was quantitatively assessed using chlorophenol red-β-D-galactopyranoside (CPRG) and was significantly increased by 41% in the kidneys at 48 h and by 49, 63, and 46% in the stomach, duodenum, and liver, respectively, at 72 h after the first dose of oral delivery of pCMV-lacZ/PNT formulation. The organs with β-Gal activity were confirmed for the presence of pCMV-lacZ DNA with Southern blotting analysis and intracellular tracing the TM-rhodamine-labeled DNA and the presence of mRNA by reverse transcription-real time quantitative PCR (RT-qPCR). Another plasmid (pCMV-hRluc) encoding Renilla reniformis luciferase was used to confirm the results. An increased hRluc mRNA and luciferase in stomach, duodenum, liver, and kidney were detected by RT-qPCR, ex vivo bioluminescence imaging, luciferase activity quantification, and immunostaining, respectively.

Janus cyclic peptide–polymer nanotubes

“…Figure 2 outlines the synthesis of the CP-polymer conjugates, which can be achieved via two synthetic pathways; (i) coppercatalysed azide-alkyne cycloaddition/thiol-ene (CuAAC/thiolene) or (ii) thiol-ene/CuAAC. The first step in the CuAAC/ thiol-ene pathway involved the conjugation of an alkyneterminated PBA or PCHA to the azidolysine side chain of 2 via microwave-assisted CuAAC to yield a one-armed CP-polymer intermediate (3)(4)(5)(6)(7). Microwave-assisted CuAAC has previously been shown to yield high conversions for CP-polymer conjugates using 10 mol% excess polymer relative to the CP bearing two azidolysine residues 24,26 .…”

“…The simplicity of this bottom-up approach together with the resultant uniformity and size of the self-assembled nanoscopic structures provides an attractive strategy, which favours applicability in the field of nanoscience and nanotechnology 5 . Among the different types of self-assembled architectures, nanotubular structures have gained considerable interest because of their suitability for various applications including nanomedicine 6,7 , (bio)sensing 8,9 , separation and recovery technologies 10 as well as nanoelectronics 11 . A distinct feature of tubular structures that is often absent from traditional self-organized supramolecular structures for example, micelles and vesicles, is the internal channel cavity, which in the case of self-assembled nanotubes (NTs) has a defined diameter that can provide a means for selective transport or molecular encapsulation properties.…”

Effects of PEGylation on the physicochemical properties and in vivo distribution of organic nanotubes

“…Ding et al A couple of studies of drug-loaded ONTs in animals have also been reported for oral gene delivery, 19 intravitreal delivery of anticancer drugs, 20 and intravenous delivery of irinotecan. 21 An ONT with a length of 2 µm outer diameter of 70-90 nm was found to accumulate specifically in the lung and be quickly cleared from blood circulation.…”

Perspectives on the Emerging Applications of Multifaceted Biomedical Polymeric Nanomaterials

“…Among the most researched on are those that are highly responsive to the external stimuli. A wide range of polymeric nanomaterials carrying smart switchable components has been developed over the decades [1][2][3][4][5][6][7]. For example, multistimuli responsive nanomaterials based on amphiphilic polymer composites containing hydrophilic and lipophilic macromers with environment-sensitive micellar properties have been reported [8].…”