Synthesis and characterization of polycholesteryl methacrylate–polyhydroxyethyl methyacrylate block copolymers

Zhou, Yuxiang; Kasi, Rajeswari M.

doi:10.1002/pola.22988

Cited by 31 publications

(39 citation statements)

References 71 publications

(111 reference statements)

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“…Poly(cholesteryl methacrylate) (PCMA; M n,GPC , 4000 g/mol; PDI, 1.13) and poly(methacrylic acid) (P(MAA; M n,GPC , 36000 g/mol; PDI, 1.17) displayed T g values at 82 and 228°C respectively, consistent with literature. 50,66 A representative DSC thermogram of copolymer P(MAA-co-CMA) (8 mol % CMA) exhibited a T g of 168°C valued between the two homopolymer transition temperatures. The existence of a single glass-transition temperature indicated the absence of microphase separations, suggesting an overall statistical copolymer structure.…”

Section: ■ Results and Discussionmentioning

confidence: 99%

“…Cholesteryl methacrylate (CMA) monomer was synthesized according to a modified procedure described previously in the literature ( Figure S1, Supporting Information). 49,50 The RAFT agent, 4-(cyanopentanoic acid)-4-dithiobenzoate (CPADB), was synthesized according to the procedure reported in the literature. 51,52 Membranes for dialysis (MWCO 3500) were purchased from Fisher Biotech (Cellu SepT4, regenerated cellulose-Tubular membrane).…”

Section: ■ Experimental Sectionmentioning

confidence: 99%

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Well-Defined Cholesterol Polymers with pH-Controlled Membrane Switching Activity

Sevimli¹,

İnci

Zareie

et al. 2012

Biomacromolecules

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Cholesterol has been used as an effective component of therapeutic delivery systems because of its ability to cross cellular membranes. Considering this, welldefined copolymers of methacrylic acid and cholesteryl methacrylate, poly(methacrylic acid-co-cholesteryl methacrylate) P(MAA-co-CMA), were generated as potential delivery system components for pH-controlled intracellular delivery of therapeutics. Statistical copolymers with varying cholesterol contents (2, 4, and 8 mol %) were synthesized via reversible addition−fragmentation chain transfer (RAFT) polymerization. Dynamic light scattering (DLS) analysis showed that the hydrodynamic diameters of the copolymers in aqueous solutions ranged from 5 ± 0.3 to 7 ± 0.4 nm for the copolymers having 2 and 4 mol % CMA and 8 ± 1.1 to 13 ± 1.9 nm for the copolymer having 8 mol % CMA with increasing pH (pH 4.5−7.4). Atomic force microscopy (AFM) analysis revealed that the copolymer having 8 mol % CMA formed supramolecular assemblies while the copolymers having 2 and 4 mol % CMA existed as unimers in aqueous solution. The pH-responsive behavior of the copolymers was investigated via UV−visible spectroscopy revealing phase transitions at pH 3.9 for 2 mol % CMA, pH 4.7 for 4 mol % CMA, and pH 5.4 for 8 mol % CMA. Lipid bilayers and liposomes as models for cellular membranes were generated to probe their interactions with the synthesized copolymers. The interactions were determined in a pH-dependent manner (at pH 5.0 and 7.4) using surface plasmon resonance (SPR) spectroscopy and liposome leakage assay. Both the SPR analyses and liposome leakage assays indicated that the copolymer containing 2 mol % CMA displayed the greatest polymer−lipid interactions at pH 5.0, presenting the highest binding ability to the lipid bilayer surfaces, and also demonstrating the highest membrane destabilization activity. CellTiter−Blue assay showed that the copolymers did not affect the cell viability up to 30 μM over a period of 72 h.

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Section: ■ Results and Discussionmentioning

confidence: 99%

Section: ■ Experimental Sectionmentioning

confidence: 99%

Well-Defined Cholesterol Polymers with pH-Controlled Membrane Switching Activity

Sevimli¹,

İnci

Zareie

et al. 2012

Biomacromolecules

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“…Cholesteryl methacrylate (CMA) monomer was synthesized according to a modified procedure in contradistinction to the literature. 51,52 In brief, cholesterol (2.0 g, 0.02 mol) was dissolved in the mixture of toluene containing triethylamine (5 mL, 23% v/v triethylamine/ toluene) in a 100 mL round bottom flask with a stirrer bar. …”

Section: Methodsmentioning

confidence: 99%

Synthesis, self-assembly and stimuli responsive properties of cholesterol conjugated polymers

et al. 2012

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Reversible addition-fragmentation chain transfer (RAFT) polymerization was used to generate welldefined pH-responsive biofunctional polymers as potential 'smart' gene delivery systems. A series of five poly(dimethylamino ethyl methacrylate-co-cholesteryl methacrylate) P(DMAEMA-co-CMA) statistical copolymers, with similar molecular weights and varying cholesterol content, were prepared. The syntheses, compositions and molecular weight distributions for P(DMAEMA-co-CMA) were monitored by nuclear magnetic resonance (NMR), solid-state NMR and gel permeation chromatography (GPC) evidencing well-defined polymeric structures with narrow polydispersities. Aqueous solution properties of the copolymers were investigated using turbidimetry and light scattering to determine hydrodynamic diameters and zeta potentials associated with the phase transition behaviour of P(DMAEMA-co-CMA) copolymers. UV-Visible spectroscopy was used to investigate the pH-responsive behaviour of copolymers. Hydrodynamic radii were measured in the range 10-30 nm (pH, temperature dependent) by dynamic light scattering (DLS). Charge studies indicated that P(DMAEMA-co-CMA) polymers have an overall cationic charge, mediated by pH. Potentiometric studies revealed that the buffering capacity and pK a values of polymers were dependent on cholesterol content as well as on cationic charge. The buffering capacity increased with increasing charge ratio, overall demonstrating transitions in the pH endosomal region for all five copolymeric structures. Cell viability assay showed that the copolymers displayed increasing cytotoxicity with decreasing number of cholesterol moieties. These preliminary results show the potential of these welldefined P(DMAEMA-co-CMA) polymers as in vitro siRNA delivery agents.

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“…305 [140] O O N N 306 [128] O O N N 307 [128] O O N N N 308 [128] [295,301] 310 [382] O O (CH 2 ) 6 O N N N 311 [382] (CH 2 312 [210] O O O [308] O O C 8 F 17…”

Section: End-functional Polymers and End-group Transformationsmentioning

confidence: 99%

“…MMA [296] St [296] 128* [283] S S C 12 H 25 S CO 2 H AA [91] CA [297] tBA [298] MA [299] (BMA) [300] (BMA) [300] CMA [301] MMA [122,283] (MMA) [122] BAM [302] DEAM [302,303] DMAM [302,303] EMAM [302,303] NIPAM [302][303][304][305][306] PAM [302,306] MVK [307] PVK [307] 297 [308] tBS [276] CMS [309] HMS [309] St [91,300,309] (St) [300] 4VP [310] Ip [311] 320 [312] 325 [100] 327 [309] 331 [313] 332 [313] NVP [103] 331-b-St [313] tBA-b-Ip [298] tBA-b-St [298] tBA-b-IP-b-St …”

Section: S S Cn C 2 H 5 Smentioning

confidence: 99%

Living Radical Polymerization by the RAFT Process - A Second Update

Moad¹,

Rizzardo²,

Thang³

2009

Aust. J. Chem.

906

720

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This paper provides a second update to the review of reversible deactivation radical polymerization achieved with thiocarbonylthio compounds (ZC(=S)SR) by a mechanism of reversible addition-fragmentation chain transfer (RAFT) that was published in June 2005 (Aust. J. Chem. 2005, 58, 379-410). The first update was published in November 2006 (Aust. J. Chem. 2006, 59, 669-692). This review cites over 500 papers that appeared during the period mid-2006 to mid-2009 covering various aspects of RAFT polymerization ranging from reagent synthesis and properties, kinetics and mechanism of polymerization, novel polymer syntheses and a diverse range of applications. Significant developments have occurred, particularly in the areas of novel RAFT agents, techniques for end-group removal and transformation, the production of micro/nanoparticles and modified surfaces, and biopolymer conjugates both for therapeutic and diagnostic applications.

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Synthesis and characterization of polycholesteryl methacrylate–polyhydroxyethyl methyacrylate block copolymers

Cited by 31 publications

References 71 publications

Well-Defined Cholesterol Polymers with pH-Controlled Membrane Switching Activity

Well-Defined Cholesterol Polymers with pH-Controlled Membrane Switching Activity

Synthesis, self-assembly and stimuli responsive properties of cholesterol conjugated polymers

Living Radical Polymerization by the RAFT Process - A Second Update

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