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TEM images with utilizing uranyl formate as a contrast agent for (a) 70-L-G3, (b) 50-L-G3, (c) 30-L-G3, (d) 70-DL-G3, (e) 50-DL-G3, and (f) 30-DL-G3; additional enlarged images are located in the ESI.
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Herein, we present a facile and comprehensive synthetic methodology for the preparation of polyester‐polyamidoamine (PAMAM) (i.e., polyester: polylactide [PLA] (hydrophobic) and polyamidoamine, PAMAM [hydrophilic]) polymers. A library of PLA‐PAMAM linear dendritic block copolymers (LDBCs) in which both l and d, l polylactide were employed in mass r...
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... SAXS analysis (vide infra). TEM captured aggregate morphologies of sizes (radii) ranging from 4.8 to 10.4 nm (Fig. 4 and enlarged images S25-30). Uranyl formate was used as a stain to increase the contrast between the hydrophilic and hydrophobic portions. LDBC 70-L-G3 shows a distribution of bilayered vesicles and elongated worm-like particles [ Fig. 4(a)]. 50-L-G3 produces bilayered vesicles with radii ranging from 4.8 to 6.1 nm [ Fig. 4(b)]. 30-L-G3 yields core-shell micelles with 7.1 nm radius [Fig. 4(c)]. In comparison with 70-L-G3, 70-DL-G3 showed bilayered vesicles, but no elongated wormlike particles were observed [ Fig. 4(d)]. 50-DL-G3 [Fig. 4(e)] yields bilayered vesicles, and ...
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... from 4.8 to 10.4 nm (Fig. 4 and enlarged images S25-30). Uranyl formate was used as a stain to increase the contrast between the hydrophilic and hydrophobic portions. LDBC 70-L-G3 shows a distribution of bilayered vesicles and elongated worm-like particles [ Fig. 4(a)]. 50-L-G3 produces bilayered vesicles with radii ranging from 4.8 to 6.1 nm [ Fig. 4(b)]. 30-L-G3 yields core-shell micelles with 7.1 nm radius [Fig. 4(c)]. In comparison with 70-L-G3, 70-DL-G3 showed bilayered vesicles, but no elongated wormlike particles were observed [ Fig. 4(d)]. 50-DL-G3 [Fig. 4(e)] yields bilayered vesicles, and 30-DL-G3 [Fig. 4(f)] produces coreshell micelles with the radii of 6.0 nm, 5.3 nm, ...
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... formate was used as a stain to increase the contrast between the hydrophilic and hydrophobic portions. LDBC 70-L-G3 shows a distribution of bilayered vesicles and elongated worm-like particles [ Fig. 4(a)]. 50-L-G3 produces bilayered vesicles with radii ranging from 4.8 to 6.1 nm [ Fig. 4(b)]. 30-L-G3 yields core-shell micelles with 7.1 nm radius [Fig. 4(c)]. In comparison with 70-L-G3, 70-DL-G3 showed bilayered vesicles, but no elongated wormlike particles were observed [ Fig. 4(d)]. 50-DL-G3 [Fig. 4(e)] yields bilayered vesicles, and 30-DL-G3 [Fig. 4(f)] produces coreshell micelles with the radii of 6.0 nm, 5.3 nm, ...
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... of bilayered vesicles and elongated worm-like particles [ Fig. 4(a)]. 50-L-G3 produces bilayered vesicles with radii ranging from 4.8 to 6.1 nm [ Fig. 4(b)]. 30-L-G3 yields core-shell micelles with 7.1 nm radius [Fig. 4(c)]. In comparison with 70-L-G3, 70-DL-G3 showed bilayered vesicles, but no elongated wormlike particles were observed [ Fig. 4(d)]. 50-DL-G3 [Fig. 4(e)] yields bilayered vesicles, and 30-DL-G3 [Fig. 4(f)] produces coreshell micelles with the radii of 6.0 nm, 5.3 nm, ...
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... vesicles and elongated worm-like particles [ Fig. 4(a)]. 50-L-G3 produces bilayered vesicles with radii ranging from 4.8 to 6.1 nm [ Fig. 4(b)]. 30-L-G3 yields core-shell micelles with 7.1 nm radius [Fig. 4(c)]. In comparison with 70-L-G3, 70-DL-G3 showed bilayered vesicles, but no elongated wormlike particles were observed [ Fig. 4(d)]. 50-DL-G3 [Fig. 4(e)] yields bilayered vesicles, and 30-DL-G3 [Fig. 4(f)] produces coreshell micelles with the radii of 6.0 nm, 5.3 nm, ...
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... 50-L-G3 produces bilayered vesicles with radii ranging from 4.8 to 6.1 nm [ Fig. 4(b)]. 30-L-G3 yields core-shell micelles with 7.1 nm radius [Fig. 4(c)]. In comparison with 70-L-G3, 70-DL-G3 showed bilayered vesicles, but no elongated wormlike particles were observed [ Fig. 4(d)]. 50-DL-G3 [Fig. 4(e)] yields bilayered vesicles, and 30-DL-G3 [Fig. 4(f)] produces coreshell micelles with the radii of 6.0 nm, 5.3 nm, ...
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... et al. postulated the crystallization of the PLLA hydrophobic block following microphase separation in a selective solvent lead to destabilization of spherical particles, which fuse with other spherical micelles to grow into worm-like aggregates. 64 In addition to the morphologies presented in Figures 4 and 5, elongated micelles, cubes, and tube-like nanostructures have been observed for these PLLA-PAMAM and PDLLA-PAMAM LDBCs under varying conditions. This work is currently on going with efforts toward understanding the selfassembly mechanism using both computational modeling and analytical characterization. ...
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... SAXS analysis (vide infra). TEM captured aggregate morphologies of sizes (radii) ranging from 4.8 to 10.4 nm (Fig. 4 and enlarged images S25-30). Uranyl formate was used as a stain to increase the contrast between the hydrophilic and hydrophobic portions. LDBC 70-L-G3 shows a distribution of bilayered vesicles and elongated worm-like particles [ Fig. 4(a)]. 50-L-G3 produces bilayered vesicles with radii ranging from 4.8 to 6.1 nm [ Fig. 4(b)]. 30-L-G3 yields core-shell micelles with 7.1 nm radius [Fig. 4(c)]. In comparison with 70-L-G3, 70-DL-G3 showed bilayered vesicles, but no elongated wormlike particles were observed [ Fig. 4(d)]. 50-DL-G3 [Fig. 4(e)] yields bilayered vesicles, and ...
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... from 4.8 to 10.4 nm (Fig. 4 and enlarged images S25-30). Uranyl formate was used as a stain to increase the contrast between the hydrophilic and hydrophobic portions. LDBC 70-L-G3 shows a distribution of bilayered vesicles and elongated worm-like particles [ Fig. 4(a)]. 50-L-G3 produces bilayered vesicles with radii ranging from 4.8 to 6.1 nm [ Fig. 4(b)]. 30-L-G3 yields core-shell micelles with 7.1 nm radius [Fig. 4(c)]. In comparison with 70-L-G3, 70-DL-G3 showed bilayered vesicles, but no elongated wormlike particles were observed [ Fig. 4(d)]. 50-DL-G3 [Fig. 4(e)] yields bilayered vesicles, and 30-DL-G3 [Fig. 4(f)] produces coreshell micelles with the radii of 6.0 nm, 5.3 nm, ...
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... formate was used as a stain to increase the contrast between the hydrophilic and hydrophobic portions. LDBC 70-L-G3 shows a distribution of bilayered vesicles and elongated worm-like particles [ Fig. 4(a)]. 50-L-G3 produces bilayered vesicles with radii ranging from 4.8 to 6.1 nm [ Fig. 4(b)]. 30-L-G3 yields core-shell micelles with 7.1 nm radius [Fig. 4(c)]. In comparison with 70-L-G3, 70-DL-G3 showed bilayered vesicles, but no elongated wormlike particles were observed [ Fig. 4(d)]. 50-DL-G3 [Fig. 4(e)] yields bilayered vesicles, and 30-DL-G3 [Fig. 4(f)] produces coreshell micelles with the radii of 6.0 nm, 5.3 nm, ...
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... of bilayered vesicles and elongated worm-like particles [ Fig. 4(a)]. 50-L-G3 produces bilayered vesicles with radii ranging from 4.8 to 6.1 nm [ Fig. 4(b)]. 30-L-G3 yields core-shell micelles with 7.1 nm radius [Fig. 4(c)]. In comparison with 70-L-G3, 70-DL-G3 showed bilayered vesicles, but no elongated wormlike particles were observed [ Fig. 4(d)]. 50-DL-G3 [Fig. 4(e)] yields bilayered vesicles, and 30-DL-G3 [Fig. 4(f)] produces coreshell micelles with the radii of 6.0 nm, 5.3 nm, ...
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... vesicles and elongated worm-like particles [ Fig. 4(a)]. 50-L-G3 produces bilayered vesicles with radii ranging from 4.8 to 6.1 nm [ Fig. 4(b)]. 30-L-G3 yields core-shell micelles with 7.1 nm radius [Fig. 4(c)]. In comparison with 70-L-G3, 70-DL-G3 showed bilayered vesicles, but no elongated wormlike particles were observed [ Fig. 4(d)]. 50-DL-G3 [Fig. 4(e)] yields bilayered vesicles, and 30-DL-G3 [Fig. 4(f)] produces coreshell micelles with the radii of 6.0 nm, 5.3 nm, ...
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... 50-L-G3 produces bilayered vesicles with radii ranging from 4.8 to 6.1 nm [ Fig. 4(b)]. 30-L-G3 yields core-shell micelles with 7.1 nm radius [Fig. 4(c)]. In comparison with 70-L-G3, 70-DL-G3 showed bilayered vesicles, but no elongated wormlike particles were observed [ Fig. 4(d)]. 50-DL-G3 [Fig. 4(e)] yields bilayered vesicles, and 30-DL-G3 [Fig. 4(f)] produces coreshell micelles with the radii of 6.0 nm, 5.3 nm, ...
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... et al. postulated the crystallization of the PLLA hydrophobic block following microphase separation in a selective solvent lead to destabilization of spherical particles, which fuse with other spherical micelles to grow into worm-like aggregates. 64 In addition to the morphologies presented in Figures 4 and 5, elongated micelles, cubes, and tube-like nanostructures have been observed for these PLLA-PAMAM and PDLLA-PAMAM LDBCs under varying conditions. This work is currently on going with efforts toward understanding the selfassembly mechanism using both computational modeling and analytical characterization. ...
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Citations
... Recently, we reported an accessible and robust synthetic methodology for the preparation of a library of LDBCs. 15 Bilayer vesicles were observed for the systems consisting of hydrophobic portions >50 wt % (CAC <6.59 mg/L) and attracted particular interest due to their biomimetic nature (i.e., resembling biological vesicles). This work has laid the foundation for a diverse library of biocompatible and biodegradable materials, which provides evidence of potential applications in nanomedicine. ...
... PAMAM-G3-Boc and C3 were prepared as previously reported. 15,29 All of the synthetic procedures were conducted under an ultrapurified nitrogen atmosphere using standard organic synthesis techniques (e.g., Schlenk line) unless otherwise specified. Chloroform (99.9%, ...
... The PAMAM dendron was synthesized according to a previously reported procedure in which ethanolamine acted as the focal point. 15 To preserve the hydroxyl focal point as the principal nucleophile, the terminal amine groups were protected with di-tert-butyl dicarbonate (Boc). 15 Boc-protected LDBC intermediates (i.e., before making the dendritic portion hydrophilic) were made by the ROP of εcaprolactone, employing Sn(Oct) 2 as the catalyst. ...
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Abstract
This study summarizes the synthesis, characterization, and evaluation of a library of biocompatible self-assembling Janus dendrimers (JDs) and their resulting nanostructures possessing either a cationic (NH3+), anionic (COO-), or neutral (OH) surface. Strategically designed for applications in therapeutic delivery, the dendrimers are comprised of a polyamidoamine (PAMAM) dendron as the hydrophilic portion and fatty acid (FA) functionalized dendrons as the hydrophobic portion. The physicochemical characterization and in vitro cell viability of amphiphilic JDs were performed. Microscopy (TEM) and dynamic light scattering (DLS) analysis indicate the size (i.e., diameters) of spherical nanoaggregates ranging from 40 to 100 nm with zeta-potential values ranging from -17.9 to +58.7 mV with respect to the terminal functional group of the JD employed. Furthermore, these systems exhibited spherical nanoaggregates with critical aggregate concentrations (CAC) ranging from 2.8 to 7.0 mg/L. At low concentrations (<200 g/mL), JDs nanoaggregates showed minimal cell growth inhibitory properties in the in vitro testing, demonstrating their safety. The results of this study prove that a simple yet strategic combination of chemically distinctive dendritic segments can afford a versatile library of unique JDs nanoplatforms with excellent potential for biomedical applications.
