Spectroscopic Characterization of Core-Based Hyperbranched Poly(ethyleneimine) and Dendritic Poly(propyleneimine) as Selective Uptake Devices

Abstract

Dendritic polymers have a wide range of potential applications; however, the extensive synthesis and limited availability of bulk quantities of dendrimers restrict their use. Core-based hyperbranched polymers (CBHPs) are, therefore, an attractive alternative to dendrimers for many applications. The selectivity of core-based hyperbranched poly(ethyleneimine), as a host for phenol blue and 2-hydroxy Nile red guests, was investigated using absorption and fluorescence spectroscopies. Research results are compared to those for its dendritic counterpart, poly(propyleneimine). Phenol blue is known to associate near the core in both the CBHPs and dendrimers investigated. The interfering agent, 2-hydroxy Nile red, has also been shown to associate with these polymers; however, this interaction occurs in the outermost branches. In this work, it was found that phenol blue was sequestered in both the CBHPs and dendrimers in the presence of interfering agent, and this association appeared to be the same as that of the polymers with phenol blue alone. Although the presence of 2-hydroxy Nile red did affect the association of phenol blue, there was still considerable association even when 2-hydroxy Nile red was in 10-fold excess. The association of phenol blue with both the CBHPs and dendrimers was stable and robust; however, the association of 2-hydroxy Nile red was relatively weak and unstable.

A Comparative Study on the Photophysics and Photochemistry of Xanthene Dyes in the Presence of Polyamidoamine (PAMAM) Dendrimers

“…Interestingly, K bind values followed the order Eos/PAMAM<Ery/PAMAM<RB/PAMAM for each PAMAM generation, which suggested a certain selectivity of the dendrimers toward xanthene dyes. This property of dendrimers has already been previously reported by other researchers, with solvatochromic dyes as fluorescent probes . In the case of xanthene dyes, Balzani et al.…”

Insights into Azetidine Polymerization for the Preparation of Poly(propylenimine)-Based CO2 Adsorbents

“…Owing to the efficiency of PEI, recent work has focused on closely related polymers, such as poly­(propylenimine) (PPI). While PPI is well-studied in applications associated with metal binding, , drug delivery, − and water purification, , comparably less work has appeared on its use in CO 2 separations. , Further, the existing studies primarily utilize dendritic poly­(propyleneimine) structures, with their dynamics and rheological properties being well-characterized. − Dendrimers are attractive due to the low polydisperities achieved during synthesis; however, their involved synthesis protocol has limited their extensive industrial application.…”

MicroRNA and Drug Delivery

“…PEI is a polycation polymer capable of complexing with DNA and protecting nucleic acids from nuclease degradation. PEI polymers can be synthesized in the nanoscale allowing for cellular endocytosis and also allowing for pH-buffering capability [230]. The number of positive charges in the polymer and negative phosphate groups within the RNA determines the size and structure of the resulting complexes (termed "polyplexes" or "polymersomes").…”