Synthesis of Poly(ethylene glycol)-Polydiacetylene Conjugates and Their Micellar and Chromic Characteristics

Abstract

In this report, novel polymer-lipid conjugates were synthesized and their unique micellar and chromic properties were studied. The conjugates were synthesized by the liquid-phase peptide synthesis method using methoxy(polyethylene glycol)-amine (mPEG-NH2, MW2000) as a supporting material. One and two 10,12-pentacosadiynoic acid (PCDA) groups were conjugated to mPEG-NH2 to prepare mPEG-PCDA and mPEG-PCDA2, respectively. The polymer conjugates could form nanometer-sized micelles in aqueous media and be further polymerized under the exposure of UV 254 nm due to the UV sensitive nature of PCDA. It was observed that mPEG-PCDA2 micelle showed very distinctive photochromism and thermochromism in response to UV or heat, whereas mPEG-PCDA did not display any chromic properties. Moreover, a distinctive chromic property change was observed by adding alpha-cyclodextrin as a model biological molecule to the micelle solution. Due to their unique properties such as high water-solubility, cross-linkable micelle formation with a nano-scaled size, and stimuli-responsive chromic nature, the polymer-lipid conjugates would be useful for various biomedical applications, in particular as a nano-carrier for drug delivery and biosensor.

Sequentially Programmable and Cellularly Selective Assembly of Fluorescent Polymerized Vesicles for Monitoring Cell Apoptosis

“…Poly(ethylene glycol) (PEG) doping was then implemented to address this issue. Methoxy poly(ethylene glycol)‐conjugated diacetylene (PEG‐DA) was prepared according to a literature procedure 34, 35. Doping PEG‐DA to DA generates a DA vesicle coated with PEG on its surface.…”

“…All of these were used without further purification. Methoxy PEG‐DA was synthesized and purified according to procedures reported previously 34, 35. The synthesis and characterization of DC were shown in the Supporting Information.…”

Characteristics of PEGylated Polydiacetylene Liposome and its Inclusion Complex Formation with α-Cyclodextrin

“…Methoxy poly(ethylene glycol)-conjugated PCDA monomer (mPEG-PCDA) was successfully synthesized according to our previously reported method. 8 The molecular weight of the mPEG-PCDA monomer lipid was measured as 2645.1 g/mol by MALDI-TOF mass spectrometry. 8 A mixture of mPEG-PCDA conjugate and PCDA (1:9 molar ratio) was prepared in chloroform, followed by solvent evaporation under a stream of N 2 gas.…”

“…8 The molecular weight of the mPEG-PCDA monomer lipid was measured as 2645.1 g/mol by MALDI-TOF mass spectrometry. 8 A mixture of mPEG-PCDA conjugate and PCDA (1:9 molar ratio) was prepared in chloroform, followed by solvent evaporation under a stream of N 2 gas. Distilled water was added to yield a total PCDA lipid concentration of 1 mM and the resulting suspension was then sonicated using a bath-type sonicator for 15 min.…”

Drug Delivery and Imaging with Polydiacetylene Micelles

“…Distribution of total radioactivity in different organs (from left to right: adrenal glands, blood, bone marrow, brain, heart, intestine walls, kidney medulla, kidney cortex, liver, lungs, and spleen) of Wistar rats after single intravenous administration of www.chemeurj.org phylic chain, but bearing a poly(ethylene glycol) (PEG) chain in lieu of the NTA polar head. [10] With this PEGylation strategy, we expected to minimize the in vivo clearance of the micelle while preserving its stability and cargo-shielding properties. [11] In fact, PEG-coating of the micelle contributes to steric protection from plasma proteins (opsonins), which classically bind to objects of foreign origin and trigger phagocytosis by macrophages.…”