Facile Approach for DNA Encapsulation in Functional Polyion Complex for Triggered Intracellular Gene Delivery: Design, Synthesis, and Mechanism

Abstract

A facile route for DNA encapsulation in triggered intracellular degradable polymer microcapsules has been achieved via electrostatic interaction, using a polycation, that is, poly[(dimethylamino)ethyl methacrylate] end-capped with cholesterol moiety (Chol-PDMAEMA(30)), along with a polyanion named MePEG2000-block-poly(methacrylic acid) carring partial thiol groups (MePEG2000-b-PMAA(SH)). The encapsulation procedure involves three steps: (i) DNA was first complexed with the polycation (Chol-PDMAEMA(30)); (ii) the complex was then further set into interaction with the anion-containing MePEG2000-b-PMAA(SH); and (iii) the compound carrier was subsequently obtained by cross-linking the thiol groups of the MePEG2000-b-PMAA(SH) to form disulfide linkages. The interactions between every pair among calf thymus DNA, Chol-PDMAEMA(30), and MePEG2000-b-PMAA(SH) were studied by agarose gel retardation assay and ethidium bromide displacement assay. The results indicate that the prepared microcapsules may remain stable during systemic circulation, but degrade and release the carried DNA in a cellular reducing environment. Furthermore, the biophysical properties of the microcapsule have been investigated by zeta-potential, laser light scattering, and transmission electron microscopy (TEM) measurements.

Effect of cholesterol-poly(N,N-dimethylaminoethyl methacrylate) on the properties of stimuli-responsive polymer liposome complexes

“…3A and B shows the 1 H NMR spectra of PDMAEMA and CHO-PDMAEMA, respectively. The most intense bands were similar in both spectra and were ascribed to PDMAEMA [16,22]: (a) the methyl group at 0.9-1.1 ppm; (b) the peaks related with the CH 2 from PDMAEMA backbone at about 1.8-2.0 ppm; (c) the O CH 2 peak at 4.1 ppm; (d) the (CH 3 ) 2 N peak at 2.6 ppm and (e) the CH 2 N peak at 2.3 ppm. The presence of the cholesteryl-2-bromoisobutyrate initiator [16,19] from the cholesteryl CH 3 singlet at 0.7 ppm (g) and the double bound (CH C from CHO) peak at 5.4 ppm (f), both of them labeled in the spectra, reveals the success of the polymerization reaction (Fig.…”

“…Therefore, CHO would facilitate the anchoring of the thermo and pH-sensitive N,N-dimethylaminoethyl methacrylate (DMAEMA) polymer into the liposomal membrane. In a recent study [16,17], CHO-PDMAEMA was obtained by oxyanion-initiated polymerization, a complex and time consuming method. However, the ATRP method of synthesis is much simpler and uses mild conditions of polymerization along with a rigorous control of the polymer properties.…”

Antibacterial Effects of Poly(2-(dimethylamino ethyl)methacrylate) against Selected Gram-Positive and Gram-Negative Bacteria

“…The pKa of the hostasolconjugated and reducible analogues was not determined as these molecules were not used in pH determination experiments. 21 . pDMAEMA tested with hostasol attached.…”

Synthesis and characterization of a pH-sensitive shielding system for polycation gene carriers

“…Walker et al [12,13] developed PEG-shielded polyplexes, of which the lower pH of the endosome triggers the removal of PEG due to instability of pH-labile bonds, such as hydrazone bond. Ni et al [14] synthesized a polyanion and used it to coat the polyplex by electrostatic interactions. However, chain-exchanging reaction of polyanion with DNA in the complexes occurred and DNA was released when excess polyanion was added.…”