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Characterization of complexation of poly (N-isopropylacrylamide-co-2-(dimethylamino) ethyl methacrylate) thermoresponsive cationic nanogels with salmon sperm DNA.

Moselhy J, Vira T, Liu FF, Wu XY - Int J Nanomedicine (2009)

Bottom Line: Quaternized P[NIPAM/DMAEMAQ] TCNGs did not undergo sharp VPT up to 50 degrees C.The VPT of P[NIPAM/DMAEMAQ]/sasDNA diminished in magnitude with increasing W(p)/W(d) suggesting greater compaction of the polyplexes.The findings demonstrate that stable TCNGs can be prepared with controllable responsive properties determined by the nature of the cationic charge incorporated and may have potential as vehicles for DNA delivery.

View Article: PubMed Central - PubMed

Affiliation: Department of Pharmaceutical Sciences, Leslie Dan Faculty of Pharmacy, University of Toronto, Toronto, ON, Canada M5S 3M2.

ABSTRACT
Thermoresponsive cationic nanogel (TCNG) networks based on N-isopropylacrylamide (NIPAM), 2-(dimethylamino)ethyl methacrylate (DMAEMA), and quaternary alkyl ammonium halide salts of DMAEMA (DMAEMAQ) were synthesized by dispersion polymerization technique. The thermoresponsive properties of TCNGs and TCNG-salmon sperm DNA (sasDNA) polyplexes were characterized in aqueous media of various pH and ionic strength. P[NIPAM] and P[NIPAM/DMAEMA] TCNGs exhibited sharp volume phase transition (VPT) in water at critical temperatures (T(c)) of 32 degrees C and 36 degrees C, respectively. Quaternized P[NIPAM/DMAEMAQ] TCNGs did not undergo sharp VPT up to 50 degrees C. The VPT of uncomplexed TCNGs were sensitive to the ionic composition and ionic strength of salts in solution, but were insensitive to pH in the range 5.0 to 7.4. The VPT of P[NIPAM/DMAEMAQ]/sasDNA diminished in magnitude with increasing W(p)/W(d) suggesting greater compaction of the polyplexes. The distinct phase-transition properties of P[NIPAM/DMAEMA]/sasDNA and P[NIPAM/DMAEMAQ]/sasDNA polyplexes were attributed to the condensing capability of polycations and to differences in the spatial distribution of structural charges in quaternized and nonquaternized networks. The findings demonstrate that stable TCNGs can be prepared with controllable responsive properties determined by the nature of the cationic charge incorporated and may have potential as vehicles for DNA delivery.

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Temperature dependence of particle size of NDQPI6/sasDNA complexes with in DDIW as a function of Wp/Wd.
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f8-ijn-4-153: Temperature dependence of particle size of NDQPI6/sasDNA complexes with in DDIW as a function of Wp/Wd.

Mentions: The thermal transition profiles of NDQPI6/sasDNA polyplexes in 150 mM pH 7.4 PBS and deionized water are shown in Figure 7 and Figure 8, respectively. The NDQPI6/sasDNA polyplexes aggregate in PBS at a temperature well below that of uncomplexed NDQPI6 (Tc ∼36 °C) and much closer to the LCST of P[NIPAM] (Tc ∼32 °C). This is in contrast to the behavior observed for ND9-2/sasDNA polyplex, which was stabilized by complexation. As with ND9-2/sasDNA, the thermal response profile of NDQPI6/sasDNA profile was insensitive to Wp/Wd. Incubation of the sasDNA with NDQPI6 for a 72 h period did not alter the shape of the transition profile.


Characterization of complexation of poly (N-isopropylacrylamide-co-2-(dimethylamino) ethyl methacrylate) thermoresponsive cationic nanogels with salmon sperm DNA.

Moselhy J, Vira T, Liu FF, Wu XY - Int J Nanomedicine (2009)

Temperature dependence of particle size of NDQPI6/sasDNA complexes with in DDIW as a function of Wp/Wd.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2747350&req=5

f8-ijn-4-153: Temperature dependence of particle size of NDQPI6/sasDNA complexes with in DDIW as a function of Wp/Wd.
Mentions: The thermal transition profiles of NDQPI6/sasDNA polyplexes in 150 mM pH 7.4 PBS and deionized water are shown in Figure 7 and Figure 8, respectively. The NDQPI6/sasDNA polyplexes aggregate in PBS at a temperature well below that of uncomplexed NDQPI6 (Tc ∼36 °C) and much closer to the LCST of P[NIPAM] (Tc ∼32 °C). This is in contrast to the behavior observed for ND9-2/sasDNA polyplex, which was stabilized by complexation. As with ND9-2/sasDNA, the thermal response profile of NDQPI6/sasDNA profile was insensitive to Wp/Wd. Incubation of the sasDNA with NDQPI6 for a 72 h period did not alter the shape of the transition profile.

Bottom Line: Quaternized P[NIPAM/DMAEMAQ] TCNGs did not undergo sharp VPT up to 50 degrees C.The VPT of P[NIPAM/DMAEMAQ]/sasDNA diminished in magnitude with increasing W(p)/W(d) suggesting greater compaction of the polyplexes.The findings demonstrate that stable TCNGs can be prepared with controllable responsive properties determined by the nature of the cationic charge incorporated and may have potential as vehicles for DNA delivery.

View Article: PubMed Central - PubMed

Affiliation: Department of Pharmaceutical Sciences, Leslie Dan Faculty of Pharmacy, University of Toronto, Toronto, ON, Canada M5S 3M2.

ABSTRACT
Thermoresponsive cationic nanogel (TCNG) networks based on N-isopropylacrylamide (NIPAM), 2-(dimethylamino)ethyl methacrylate (DMAEMA), and quaternary alkyl ammonium halide salts of DMAEMA (DMAEMAQ) were synthesized by dispersion polymerization technique. The thermoresponsive properties of TCNGs and TCNG-salmon sperm DNA (sasDNA) polyplexes were characterized in aqueous media of various pH and ionic strength. P[NIPAM] and P[NIPAM/DMAEMA] TCNGs exhibited sharp volume phase transition (VPT) in water at critical temperatures (T(c)) of 32 degrees C and 36 degrees C, respectively. Quaternized P[NIPAM/DMAEMAQ] TCNGs did not undergo sharp VPT up to 50 degrees C. The VPT of uncomplexed TCNGs were sensitive to the ionic composition and ionic strength of salts in solution, but were insensitive to pH in the range 5.0 to 7.4. The VPT of P[NIPAM/DMAEMAQ]/sasDNA diminished in magnitude with increasing W(p)/W(d) suggesting greater compaction of the polyplexes. The distinct phase-transition properties of P[NIPAM/DMAEMA]/sasDNA and P[NIPAM/DMAEMAQ]/sasDNA polyplexes were attributed to the condensing capability of polycations and to differences in the spatial distribution of structural charges in quaternized and nonquaternized networks. The findings demonstrate that stable TCNGs can be prepared with controllable responsive properties determined by the nature of the cationic charge incorporated and may have potential as vehicles for DNA delivery.

Show MeSH
Related in: MedlinePlus