Structure‐Transport Relationship of Dendritic Core‐Shell Nanocarriers for Polar Dyes

Abstract

TriPEGylated functionalized dendritic poly(ethylene imines) were synthesized and their transportation properties for rose Bengal (up to 50 guests per dendrimer) were evaluated. A critical aggregation concentration was observed, demonstrating the formation of aggregates among the dendrimers. The structure‐activity relationships show that their encapsulation capacities were dependent linearly on the density of the PEG shell, either as PEG length or degree of functionality, which confirmed that the PEG chains play a predominant role in the encapsulation process. It further gives some insights that the guest molecules appeared to be predominantly located in the PEG shell rather than in the core.

Oligosaccharide Shells as a Decisive Factor for Moderate and Strong Ionic Interactions of Dendritic Poly(ethylene imine) Scaffolds under Shear Forces

“…Thus, the analyte is mainly bound to the PEI core scaffold and the formed complexes are very stable. This complexation scheme is supported by the results of Haag and co-workers, [5] who also verified that at lower dye concentrations anionic dye molecules primarily interact with the cationic PEI core in core-shell architectures. Owing to the larger size of B 12 in the "Group 2 molecules" category, partly surface-driven interactions can also be assumed on the surface of the globular-shaped PEI-OS [19] (Figure 2 b).…”

“…Based on the present and previous studies, [3,5,12,[13][14][15][16][17][18][27][28][29] we would like to suggest the following general interaction scheme between low-molar-mass analyte molecules and PEI-OS as presented in Figure 2. With weak interactions (Figure 2 a), "Group 1 molecules" can be located anywhere in PEI-OS architecture, but the interactions are weak and highly dy-namic and thus, the analyte uptake is low.…”

“…[1,2] The variation in the structural composition of these dendritic core-shell architectures, using dendrimers and hyperbranched polymers as core components, allows the tailoring of analyte uptake in the core and/or shell compartment of those architectures. [3][4][5][6][7][8] In most cases, polar and non-polar dyes have been used as model drugs, but only few relevant drugs have been tested in respect to their potential applications. [9,10] The main driving forces for encapsulating/complexing analyte molecules in various core-shell architectures [10,11,12] are ionic/electrostatic and hydrophobic-hydrophobic interactions, but also combinations of these.Recently, our studies showed that cationic poly(propylene imine) dendrimers and hyperbranched poly(ethylene imine)s (PEI) decorated with oligosaccharide shells are suitable materials to complex anionic analyte molecules (e.g., ATP, [13,14] Mant-ATP, [15] Rose Bengal [16] and nucleic acids [17,18] ).…”

Charge‐selective separation and recovery of organic ions by polymeric micelles

“…The more polar core of PG‐COOH2@C16 should be responsible for its aggregation. Aggregation of similar core–shell‐structured polymers based on hyperbranched polymers has been observed by other researchers and it is termed multimicelle aggregate, and the behavior of guest entrapment by such aggregate is also termed “encapsulation.” PAA@PS was previously shown to exist as a physical micelle ( D h = 19 nm at 10 −6 M in chloroform by DLS) …”

Xanthate‐mediated polymerization of styrene on hyperbranched polyethylenimine: Synthesis, characterization, and guest‐encapsulating property

“…Hyperbranched polyethylenimine (HPEI) is a commercially available, hydrophilic, multifunctional polymer, with active amino protons distributed in core through shell of the globular structure and constitute a platform of a variety of chemical modifications. Core‐shell amphiphiles based on HPEI were synthesized via amidation, Michael addition, quaternization or alkylation of the amino groups, and the resulting globular amphiphiles could be used as nanocapsule in host–guest chemistry 22–28. However, to date, most of the derivatives were obtained by modification with small molecules, the drawback of such amphiphilic derivative of HPEI included their tendency to aggregate8, 23 and limited miscibility with polymer matrix.…”