Polymeric worm micelles as nano-carriers for drug delivery.
TL;DR: W worm micelles as blends of degradable polylactic acid and inert block copolymer amphiphiles were prepared for controlled release and initial study of carrier transport through nano-porous media, suggesting a new class of hydrophobic drug nano-carriers that are capable of tissue permeation as well as controlled release.
Abstract: Nanoscale carriers of active compounds, especially drugs, need not be spherical in shape. Worm micelles as blends of degradable polylactic acid (PLA) and inert block copolymer amphiphiles were prepared for controlled release and initial study of carrier transport through nano-porous media. The loading capacity of a typical hydrophobic drug, Triamterene, and the release of hydrophobic dyes were evaluated together with morphological changes of the micelles. Degradation of PLA by hydrolysis led to the self-shortening of worms and a clear transition towards spherical micelles, correlating with the release of hydrophobic dyes. Perhaps equally important for application is the flexibility of worm micelles, which we show allows them to penetrate nanoporous gels where 100 nm sized vesicles cannot enter. Such gels have served as tissue models, and so the results here collectively suggest a new class of hydrophobic drug nano-carriers that are capable of tissue permeation as well as controlled release.
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TL;DR: In this paper, a sequential polymerization-induced self-assembly (PISA) and crystallization-driven selfassembly (CDSA) method was proposed to prepare crystalline nanorods on a large scale.
13 citations
TL;DR: In this article, the formation of "hairy-type" and "flower-like" micelles in aqueous and an unusual morphology of the “hairytype” micells was found in the lengthiest PEO and PAAm blocks.
13 citations
TL;DR: An insight is shown into how the addition of poly(ethylene oxide) homopolymer to a range of polymersome dispersions composed of amphiphilic di- and triblock copolymers transposes into much larger block copolymer systems which show great promise as biomimetic delivery vectors for controlled release.
Abstract: We have studied the addition of poly(ethylene oxide) homopolymer (PEO) to a range of polymersome dispersions composed of amphiphilic di- and triblock copolymers. A number of EnBm EnBmEn and BmEnBm ...
12 citations
TL;DR: In this article, self-consistent field theory (SCFT) was used to study the self-assembly of isolated block copolymer aggregates and showed that the tendency to form cylindrical and lamellar structures is sometimes overestimated due to neglect of edge effects due to the finite size of these aggregates.
Abstract: Diblock copolymers blended with homopolymer may self-assemble into spherical, cylindrical, or lamellar aggregates. Transitions between these structures may be driven by varying the homopolymer diblock molecular weight or composition. Using self-consistent field theory (SCFT), we reproduce these effects. Our results are compared to x-ray scattering and transmission electron microscopy measurements by Kinning et al. and good agreement is found, although the tendency to form cylindrical and lamellar structures is sometimes overestimated due to our neglect of edge effects due to the finite size of these aggregates. Our results demonstrate that SCFT can provide detailed information on the self-assembly of isolated block copolymer aggregates.
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TL;DR: In this paper, the authors investigated the mechanical properties of poly(methyl methacrylate)(PMMA)-b-poly(n-butyl acrylate) and poly(poly(methacrylated poly(n) butyl acylate) films with cylindrical and lamellar morphologies, prepared with two casting solvents.
Abstract: Electromechanical responses were investigated for poly(methyl methacrylate)(PMMA)-b-poly(n-butyl acrylate)(PnBA)-b-poly(methyl methacrylate)(PMMA) films with cylindrical and lamellar morphologies, prepared with two casting solvents. Toluene and acetone were used as casting solvents because their solubility parameters are very similar to the solubility parameters of PnBA and PMMA, respectively. The mechanical responses of films revealed that when acetone was used as a casting solvent the film formed with PMMA as a continuous phase, and when toluene was used as a casting solvent, the film formed with PnBA continuous phase. Films were pre-strained right before actuation to increase actuation performance. The film with a PnBA continuous phase with cylindrical structure showed almost 12% strain, whereas the film forms with PMMA continuous phase showed almost 4% strain in an electric field with same magnitude. These results were consistent with the results of dielectric constant data. Moreover the film that formed a PnBA continuous phase started to actuate at a lower electric field strength, and showed rapid deformation with and without electric field, compared to film with PMMA continuous phase.
12 citations
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TL;DR: The utility of polymeric micelles formed through the multimolecular assembly of block copolymers as novel core-shell typed colloidal carriers for drug and gene targeting and their feasibility as non-viral gene vectors is highlighted.
3,457 citations
TL;DR: This review examines the chemical nature of polymeric micelles as well as the methods used to characterize them with regard to drug delivery and potential medical applications, especially in cancer chemotherapy, are described and discussed.
1,200 citations
TL;DR: Experiments with poly(1,2-butadiene-b-ethylene oxide) diblock copolymers are described, which form Y-junctions and three-dimensional networks in water at weight fractions of PEO intermediate to those associated with vesicle and wormlike micelle morphologies.
Abstract: Amphiphilic compounds such as lipids and surfactants are fundamental building blocks of soft matter. We describe experiments with poly(1,2-butadiene-b-ethylene oxide) (PB-PEO) diblock copolymers, which form Y-junctions and three-dimensional networks in water at weight fractions of PEOintermediate to those associated with vesicle and wormlike micelle morphologies. Fragmentation of the network produces a nonergodic array of complex reticulated particles that have been imaged by cryogenic transmission electron microscopy. Data obtained with two sets of PB-PEOcompounds indicate that this type of self-assembly appears above a critical molecular weight. These block copolymers represent versatile amphiphiles, mimicking certain low molecular weight three-component (surfactant/water/oil) microemulsions, without addition of a separate hydrophobe.
1,126 citations
TL;DR: With all compositions, in both 100 nm and giant vesicles, the average release time reflects a highly quantized process in which any given vesicle is either intact and retains its encapsulant, or is porated and slowly disintegrates.
638 citations
TL;DR: A low molecular weight poly(ethyleneoxide)-poly(butadiene) (PEO-PB) diblock copolymer containing 50 weight percent PEO forms gigantic wormlike micelles at low concentrations (<5 percent by weight) in water.
Abstract: A low molecular weight poly(ethyleneoxide)-poly(butadiene) (PEO-PB) diblock copolymer containing 50 weight percent PEO forms gigantic wormlike micelles at low concentrations (<5 percent by weight) in water. Subsequent generation of free radicals with a conventional water-based redox reaction leads to chemical cross-linking of the PB cores without disruption of the cylindrical morphology, as evidenced by cryotransmission electron microscopy and small-angle neutron scattering experiments. These wormlike rubber micelles exhibit unusual viscoelastic properties in water.
626 citations