Amphiphilic β‐cyclodextrin‐based star‐like block copolymer unimolecular micelles for facile in situ preparation of gold nanoparticles

Abstract

Multifunctional polymer unimolecular micelles, which are used as templates to fabricate stable gold nanoparticles (GNPs) in one‐step without external reductant, have been designed and prepared. Amphiphilic 21‐arm star‐like block copolymers β‐cyclodextrin‐{poly(lactide)‐poly(2‐(dimethylamino) ethyl methacrylate)‐poly[oligo(2‐ethyl‐2‐oxazoline)methacrylate]}21 [β‐CD‐(PLA‐PDMAEMA‐PEtOxMA)21] and the precursors are synthesized by the combination of ring‐opening polymerization (ROP) and activators regenerated by electron transfer atom transfer radical polymerization (ARGET ATRP). The tertiary amine groups of PDMAEMA block reduce the AuCl4− counterion to zerovalent gold in situ, and these gold atoms combine mutually to form final GNPs. GNPs with relatively small size and narrow size distribution can be obtained in longer DMAEMA block copolymer, larger molar ratio of DMAEMA to HAuCl4 and smaller absolute concentrations of both polymer and HAuCl4. These results showed that the unimolecular micelles can be used as templates for preparing and stabilizing GNPs in situ without any external reducing agents and organic solvents, suggesting that the nanocomposite systems are latent nanocarriers for further biomedical application. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016, 54, 186–196

Co-Delivery of Imiquimod and Plasmid DNA via an Amphiphilic pH-Responsive Star Polymer that Forms Unimolecular Micelles in Water

“…2-(Dimethylamino)ethyl methacrylate (DMAEMA, >98%, TCI, Tokyo, Japan) was purified by passing through a column filled with neutral alumina to remove inhibitor before use. Oligo(2-ethyl-2-oxazoline)methacrylate (EtOxMA) has been synthesized and reported in our previous article [32]. Triethylamine (TEA, 99%, Sigma-Aldrich, St. Louis, MO, USA), toluene (Sigma-Aldrich), tetrahydrofuran (THF, Sinopharm, Beijing, China), and anisole (Sinopharm) were dried over CaH 2 and distilled under nitrogen.…”

“…Dulbecco's modified Eagle medium (DMEM), fetal bovine serum (FBS), penicillin, and streptomycin were all purchased from Invitrogen (Carlsbad, CA, USA). 21 The amphiphilic pH-responsive star copolymer was synthesized by combining activator regenerated by electron-transfer atom-transfer radical polymerization (ARGET ATRP) with ring opening polymerization (ROP) [32]. First, the synthesis of β-CD-(PLA-OH) 21 by ROP of D,L-LA (5.50 g, 37.8 mmol) in anhydrous toluene (25 mL) was carried out using β-CD (681 mg, 0.6 mmol) as an initiator and Sn(Oct) 2 (65 µL, 0.2 mmol) as a catalyst at 130 • C for 24 h. The macroinitiator β-CD-(PLA-Br) 21 was then synthesized from β-CD-(PLA-OH) 21 (5.50 g, 0.6 mmol) and TEA (3.34 mL, 24 mmol) with 2-bromoisobutyryl bromide (2.97 mL, 24 mmol) in anhydrous THF (100 mL) at room temperature.…”

“…The interaction parameters were calculated according to our previous method [32,36]. DPD simulations were conducted in the Mesocite module at 298.15 K in Materials Studio 5.0 (Accelrys Inc., San Diego, CA, USA).…”

β-Cyclodextrin-g-Poly (2-(dimethylamino) ethyl methacrylate) as the Stabilizer and Reductant to Prepare Colloid Silver Nanoparticles in situ

“…Recently, some reports have demonstrated that PDMAEMA can act as both reducing agent and stabilizer simultaneously in the formation of gold nanoparticles, [21][22][23][24] based on the fact that Poly (2-(dimethylamino) ethyl methacrylate) (PDMAEMA) is a hydrophilic polymer with temperature and pH sensitivities, excellent biocompatibility, and a well-studied environmentally responsive polymer. 25 Such an approach greatly simplified the preparation and purification of gold nanoparticles.…”

Poly(2-(diethylamino)ethyl methacrylate)-based, pH-responsive, copolymeric mixed micelles for targeting anticancer drug control release

“…[15][16][17][18] In particular, pH-responsive polymeric micelles are selfassembled by triblock or multi-block copolymers containing hydrophilic blocks, hydrophobic blocks and functional response blocks. A substantial proportion of hydrophilic/ hydrophobic block in the micelles structure improved the in vivo micelle stability and drug-loading capability but at the price of the reduced micellar pH responsiveness.…”