Amphiphilic Janus Micelles with Polystyrene and Poly(methacrylic acid) Hemispheres

Particulate systems have been widely used as containers of drugs or cells with the purpose of releasing them in a particularThe search for more effi cient therapeutic strategies and diagnosis tools is a continuous challenge. Advances in understanding the biological mechanisms behind diseases and tissues regeneration have widened the fi eld of applications of particulate systems. Particles are no more just protective systems for the encapsulated drugs, but they play an active role in the success of the therapy. Moreover, particles have been explored for innovative purposes as templates for cells growth and as diagnostic tools. Until few years ago the most relevant parameters in particles formulation were the chemistry and the size. Currently, it is known that other physical characteristics can remarkably affect the performance of particulate systems. Particles with non-conventional shapes exhibit advantages due to the increasing circulation time in blood stream, less clearance by the immune system and more effi cient cell internalization and traffi cking. Creation of compartments has been found useful to control drug release, to tune the transport of substances across biological barriers, to supply the target with more than one bioactive agent or even to act as theranostic systems. It is expected that such complex shaped and compartmentalized systems improve the therapeutic outcomes and also the patient's compliance, acting as advanced devices that serve for simultaneous diagnosis and treatment of the disease, combining agents of very different features, at the same time. In this review, we overview and analyse the most recent advances in particle shape and compartmentalization and applications of newly designed particulate systems in the biomedical fi eld.

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“…[ 262 ] Cylinders, sheets, and ribbons Poly(tert-butoxystyrene)-bpoly(butadiene)-b-poly(tertbutyl methacrylate)…”

Section: Reviewmentioning

confidence: 99%

Design Advances in Particulate Systems for Biomedical Applications

Lima

Álvarez-Lorenzo

Mano

2016

Adv Healthcare Materials

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“…Müller and coworkers prepared disc-like polymer Janus particles from assem-bled films of polystyrene-block-poly(butadiene)-block-PMMA triblock copolymer (SBM) [42], selective crosslinking of the poly(butadiene) block, and dissolution via sonication, and then assembled them into supracolloidal Janus micelles. They revisited this in another paper and described the hydrolysis of the PMMA into poly(methacrylic acid) [43]. Again, assembly into supracolloidal micelles was driven by the hydrophobic effect.…”

Section: Self-assembly Of Amphiphilic Particles Driven By the Hydrophmentioning

confidence: 99%

Physical Methods for the Preparation of Hybrid Nanocomposite Polymer Latex Particles

Teixeira

Bon

2010

Hybrid Latex Particles

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In this chapter, we will highlight conceptual physical approaches towards the fabrication of nanocomposite polymer latexes in which each individual latex particle contains one or more "hard" nanoparticles, such as clays, silicates, titanates, or other metal(oxides). By "physical approaches" we mean that the "hard" nanoparticles are added as pre-existing entities, and are not synthesized in situ as part of the nanocomposite polymer latex fabrication process. We will narrow our discussion to focus on physical methods that rely on the assembly of nanoparticles onto the latex particles after the latex particles have been formed, or its reciprocal analogue, the adhesion of polymer onto an inorganic nanoparticle. First, will discuss the phenomenon of heterocoagulation and its various driving forces, such as electrostatic interactions, the hydrophobic effect, and secondary molecular interactions. We will then address methods that involve assembly of nanoparticles onto or around the more liquid precursors (i.e., swollen/growing latex particles or monomer droplets). We will focus on the phenomenon of Pickering stabilization. We will then discuss features of particle interaction with soft interfaces, and see how the adhesion of particles onto emulsion droplets can be applied in suspension, miniemulsion, and emulsion polymerization. Finally, we will very briefly mention some interesting methods that make use of interface-driven templating for making well-defined assembled clusters and supracolloidal structures.

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“…Although the aggregate is still in thermodynamic equilibrium, the degree of stretching is different when polymers form aggregates of different morphologies. 40 For example, Zhang and Eisenberg 2 showed that spheres, rods, and vesicles were formed from PS 200 -b-PAA 21 , PS 200 -b-PAA 15 , and PS 200 -b-PAA 8 copolymers, respectively, in dimethylformamide (DMF)/water solutions. The degree of PS stretching in these three types of aggregates was 1.41, 1.26, and 0.99, respectively.…”

Section: Copolymer Composition and Concentrationmentioning

confidence: 99%

Preparation of block copolymer vesicles in solution

Soo

Eisenberg

2004

J Polym Sci B Polym Phys

369

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Block copolymer vesicles can be prepared in solution from a variety of different amphiphilic systems. Polystyreneblock-poly(acrylic acid), polystyrene-block-poly(ethylene oxide), and many other block copolymer systems can produce vesicles of a wide range of sizes; those in the range of 100 -1000 nm have been explored extensively. Different factors, such as the absolute and relative block lengths, the presence of additives (ions, homopolymers, and surfactants), the water content in the solvent mixture, the nature and composition of the solvent, the temperature, and the polydispersity of the hydrophilic block, provide control over the types of vesicles produced. Their high stability, resistance to many external stimuli, and ability to package both hydrophilic and hydrophobic compounds make them excellent candidates for use in the medical, pharmaceutical, and environmental fields.

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Amphiphilic Janus Micelles with Polystyrene and Poly(methacrylic acid) Hemispheres

Cited by 350 publications

References 12 publications

Design Advances in Particulate Systems for Biomedical Applications

Design Advances in Particulate Systems for Biomedical Applications

Physical Methods for the Preparation of Hybrid Nanocomposite Polymer Latex Particles

Preparation of block copolymer vesicles in solution

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