Interpolymer association of amphiphilic diblock copolymers bearing pendant siloxane and phosphorylcholine groups

Abstract

In this study, amphiphilic diblock copolymers (PMPC m -PTSM n ) composed of hydrophilic poly(2-methacryloylo xyethyl phosphorylcholine) (PMPC) and hydrophobic poly(3-(tris (trimethylsiloxy)silyl)propyl methacrylate) (PTSM) were prepared via RAFT-controlled radical polymerization. The subscripts m and n represent the degrees of polymerization of the PMPC and PTSM blocks, respectively. Thus, the m/n ratio represents the hydrophilic/hydrophobic balance of the block copolymer. We prepared PMPC m -PTSM n with m/n ratios of 12, 1.8, and 0.3 and studied their association behaviors in water. PMPC m -PTSM n with m/n ratios of 12 and 1.8 could dissolve in water. However, PMPC m -PTSM n with an m/n ratio of 0.3 did not directly dissolve in water. First, PMPC m -PTSM n with an m/n ratio of 0.3 dissolved in ethanol, whose solution was dialyzed in water to prepare the aqueous solution. The solubilizing state of these polymers in water was examined by light scattering, a fluorescence probe method, and TEM. These polymers took interpolymer aggregation state with various morphologies. The m/n ratios of 12, 1.8, and 0.3 yielded spherical shapes, cylindrical micelles, and vesicle interpolymer aggregate shapes, respectively.Polydimethylsiloxane (PDMS) is flexible and hydrophobic and is characterized by processability and low cytotoxicity. 7-10 Lowmolecular-weight siloxane surfactants are used to manufacture textiles, cosmetics, formulations, agricultural chemicals, paints, and other technologies. Amphiphilic diblock copolymers that contain siloxane groups, which act as a hydrophobic block, have been prepared in the previous studies. For example, diblock copolymers composed of hydrophilic PEO and PDMS 11,12 form spherical micelles, cylinders, and vesicles in water according to the hydrophilic/hydrophobic block chain length ratio, which is due to the hydrophobic interactions between siloxane blocks. Car et al. 13 prepared pH-responsive diblock copolymers composed of PDMS and poly(2-(dimethylamino)ethyl methacrylate) blocks and reported their pH-responsive behavior in an aqueous solution.Poly(2-(methacryloyloxy)ethyl phosphorylcholine) (PMPC) has pendant phosphorylcholine group, which is the same chemical structure as one of the polar parts of the phospholipids that constitutes the cell membrane. 14 PMPC is water-soluble polymer and the surfaces bound with the PMPC shows an excellent resistance for protein adsorption and cell adhesion. Seo et al. 15 reported the preparation of amphiphilic ABA triblock copolymers composed of PMPC as an "A" block and PDMS as a "B" block, as well as random copolymers composed of 2-(methacryloyloxy)ethyl phosphory lcholine (MPC) and 3-(tris(trimethylsiloxy)silyl)propyl methacrylate (TSM) units. ABA triblock copolymers could attach on the PDMS substrates, which are more stable than random copolymers. Since the PMPC unit located on the PDMS substrate surface, Additional supporting information may be found in the online version of this article.

Dendritic core derived unimolecular micelles with poly(lactic acid) arms: Synthesis and application as a phase transfer agent

“…To confirm that the polymerization is initiated from the dendritic hydroxyl‐terminated groups, low molecular weight star polymer P1 was synthesized. 1 H NMR of P1 shows a slight broadening in the signals of starting material peaks after polymerization, along with the appearance of three new signals at 1.5, 4.3, and 5.2 ppm, 57 corresponding to the methyl protons, terminal, and main chain methine protons of the lactide unit, respectively, as shown in Figure 2. At a high monomer/initiator ratio, the signals of starting material disappeared as shown in Figure S19.…”

Diblock Copolymers of Methacryloyloxyethyl Phosphorylcholine and Dopamine Methacrylamide: Synthesis and Real-Time Adsorption Dynamics by SEIRAS and RAIRS

“…In previous studies, many amphiphilic diblock copolymers were synthesized starting from the pMPC block. 10 , 57 − 60 Several solvents were used for the chain extension reaction, including methanol, 10 ethanol, 60 ethanol/chloroform (3:7 v/v), 58 methanol/DMSO (1:1 v/v), 59 and ethanol/tetrahydrofuran (THF) (1:1 or 3:1 v/v). 6 In the present study, chain extension by the units of ADOPMA from pMPC was done in MeOH, EtOH, and several mixtures of these alcohols with DMF and CHCl 3 ( Table 1 ).…”

pH- and Thermo-Responsive Water-Soluble Smart Polyion Complex (PIC) Vesicle with Polyampholyte Shells

“…Fluorescence spectroscopy measurements for PEG-Py in the presence and absence of the PIC vesicles were performed to detect PEG-Py content in the solution after dialysis. The loading capacity (LC) and loading efficiency (LE) were calculated according to the following Equations [39]:…”