Amphiphilic Linear-Dendritic Triblock Copolymers Composed of Poly(amidoamine) and Poly(propylene oxide) and Their Micellar-Phase and Encapsulation Properties

Abstract

A novel amphiphilic ABA dendritic-linear-dendritic block copolymer consisting of poly(amidoamine) and poly(propylene oxide) has been synthesized. The solution-phase behavior of the block copolymer was studied as a function of the generation of the dendritic block, ionic strength, and solution pH. The triblock self-assembles in aqueous media to form stable micelles with CMC values ranging from 10(-6) to 10(-5) M. Dynamic light scattering results indicate the formation of particles ranging from 9 to 18 nm in diameter, with smaller diameters exhibited at higher generations. Additional experiments were performed to assess the feasibility of the nanoparticles for drug delivery applications. Drug loading studies were performed with a model hydrophobic drug, triclosan, resulting in high loading efficiencies ranging from 79 to 86%w/w. The dendritic-linear-dendritic block copolymer synthesized was found to be a promising candidate for drug delivery due to its relative stability in aqueous solution and its drug encapsulation and release properties.

Drug releasing behavior of hybrid micelles containing polypeptide triblock copolymer

“…All of the micelles have core-shell structures with water-insoluble blocks forming cores and watersoluble blocks acting as coronas. One promising application of this type of aggregates is for drug delivery [1][2][3][4][5][6][7][8][9]. Usually, hydrophobic drugs can be loaded in the cores of the micelles to lower its toxicity in human body, and to prolong their circulation time in blood [10].…”

Blue-emitting PEGylated hyperbranched PAMAM: transformation of cross-linked micelles to hollow spheres controlled by the PEG grafting density

“…On the other hand, the grafted PEG chains enhance the affinity of aggregates in THF. In the earlier reports, the mid-generation dendrimers usually create a significantly deformed morphology when self-assembly driven by hydrophilic and hydrophobic interactions [21,22]. In our case, due to the flexibility of peripheral PEG arms, the rigid h-PAMAM units can be mainly directed toward one side in the block-selective solvent, eventually leading to formation of the spherical micelles with an h-PAMAM core and grafted PEG chains.…”

Effect of the Branching Pattern of Hydrophobic Dendrons on the Core Structure of Linear‐Dendritic Copolymer Micelles

“…[15][16][17][18] For example, it has been shown that critical micelle concentration (CMC) of linear-dendritic copolymers decreases with increasing generation in keeping with increasing hyrophobicity of the dendrons. [ 19,20 ] Morphology of an azo-dendron-poly(ethylene glycol) (PEG) polymer changed from nanofi bers to micelles to vesicles with increasing dendron generations. [ 21 ] However, hydrophobicity or hydrophilicity of these copolymers increases rapidly with generation of dendron because of exponential increase in the number of terminal groups and concomitant increase in dendron size.…”