Aggregation behavior in water of amphiphilic diblock copolymers bearing biocompatible phosphorylcholine and cholesteryl groups

Abstract

Poly(2-(methacryloyloxy)ethyl phosphorylcholine)-block-poly(cholesteryl 6-methacryloyloxyhexanoate) (PMPC 82 -b-PChM n ) copolymers with different PChM block lengths were prepared via reversible addition-fragmentation chain transfer controlled/living radical polymerization using a PMPC-based macro-chain transfer agent. The subscript number and n ( = 3 and 6) refer to the degree of polymerization of the PMPC and PChM blocks, respectively. PMPC 82 -b-PChM n cannot dissolve in water directly due to the strong hydrophobic nature of the PChM block. To prepare the aqueous solution, the diblock copolymer was dissolved in an organic solvent and then dialyzed against pure water. These diblock copolymers formed spherical and rod-like micelles in water, depending on the composition of cholesteryl (Chol) group in the polymer. The prepared aggregates were characterized using static light scattering, dynamic light scattering, transmission electron microscopy and fluorescence probe techniques. The characterization results suggest that the morphology of the polymer aggregates can be controlled from spherical to rod-like micelles by increasing the number of Chol groups in the polymer.

Epigenetically reprogrammed methylation landscape drives the DNA self-assembly and serves as a universal cancer biomarker

“…1b , right). Previous studies suggest that the methyl group is highly hydrophobic, and hydrophobic forces are indeed vastly involved in aggregation processes of polymers 16 . Moreover, hydrophobic driven methylation-dependent conformational changes of DNA have already been reported in the literature 12 .…”

Phosphonic Acid-Functionalized Diblock Copolymer Nano-Objects via Polymerization-Induced Self-Assembly: Synthesis, Characterization, and Occlusion into Calcite Crystals

“…Recent progress in the development of controlled/living polymerization methods such as atom transfer radical polymerization (ATRP) and reversible addition–fragmentation transfer (RAFT) polymerization has facilitated the design of a wide range of well-defined controlled-structure polymers. Many examples of well-defined PMPC-based diblock copolymers have been prepared by ATRP , and RAFT. , Of particular relevance to the present study, (1-ethoxy­carbonyl)­vinyl dimethyl­phosphate was homopolymerized via ATRP and also copolymerized using either polystyrene or poly­(methyl methacrylate) macroinitiators . While control over the polymerization of this dialkylphosphate monomer was rather poorincomplete conversions or broad molecular weight distributions ( M w / M n > 1.60) were obtained depending on the choice of catalystsubsequent hydrolysis produced the corresponding phosphoric acid-based diblock copolymers.…”

“…Many examples of well-defined PMPC-based diblock copolymers have been prepared by ATRP 25,26 and RAFT. 27,28 Of particular relevance to the present study, (1-ethoxycarbonyl)vinyl dimethylphosphate was homopolymerized via ATRP and also copolymerized using either polystyrene or poly(methyl methacrylate) macroinitiators. 29 While control over the polymerization of this dialkylphosphate monomer was rather poorincomplete conversions or broad molecular weight distributions (M w /M n > 1.60) were obtained depending on the choice of catalystsubsequent hydrolysis produced the corresponding phosphoric acid-based diblock copolymers.…”

Simulation Studies on Signature Interactions between Cancer DNA and Cysteamine-Decorated AuNPs for Universal Cancer Screening

“…It was revealed that the exterior of the agglomerated DNAs has significant variations, while the inside component is relatively stiff (see Figure c,d). It is worth noting that the methylated DNA shows a larger rigid region (shown in orange) in comparison to the unmethylated DNA, which is due primarily to the methylation-dependent hydrophobicity. , The hydrophobic forces have been found to be related to polymer aggregation . Our results demonstrate that the DNA polymeric behavior is strongly affected by DNA methylation, leading to significant differences in DNA solvation and DNA–gold affinity between the methylated and unmethylated DNA, discussed in the following sections.…”

“…16,43 The hydrophobic forces have been found to be related to polymer aggregation. 44 Our results demonstrate that the DNA polymeric behavior is strongly affected by DNA methylation, leading to significant differences in DNA solvation and DNA−gold affinity between the methylated and unmethylated DNA, discussed in the following sections.…”