The synthesis of a new zwitterionic diblock copolymer poly(l-glutamic acid)-b-poly(l-lysine) (PGA-b-PLys) is described, and its self-assembly into schizophrenic vesicles that can reversibly be produced in moderate acidic or basic aqueous solutions is reported. These pH-sensitive nanoparticles are expected to be very promising candidates in macromolecular nanobiotechnologies.

This review discusses the potential of block copolymer type macromolecular building blocks for the preparation of self‐assembled materials. Three different classes of block copolymer type architectures will be distinguished: (i) coil–coil diblock copolymers, (ii) rod–coil diblock copolymers, and (iii) rod–coil diblock oligomers. The basic principles that underlie the self‐assembly of each of these different building blocks will be discussed. These theoretical considerations are complemented with examples from recent literature that illustrate the potential of the different types of block copolymers to prepare (functional) supramolecular materials. Finally, several strategies will be presented that could allow the preparation of stimuli‐sensitive self‐assembled materials, i.e., materials whose properties can be reversibly manipulated under the action of appropriate external stimuli.

The cell is certainly one of the most complex and exciting systems in Nature that scientists are still trying to fully understand. Such a challenge pushes material scientists to seek to reproduce its perfection by building biomimetic materials with high-added value and previously unmatched properties. Thanks to their versatility, their robustness and the current state of polymer chemistry science, we believe polymer-based materials to constitute or represent ideal candidates when addressing the challenge of biomimicry, which defines the focus of this review. The first step consists in mimicking the structure of the cell: its inner compartments, the organelles, with a multicompartmentalized structure, and the rest, i.e. the cytoplasm minus the organelles (mainly cytoskeleton/cytosol) with gels or particular solutions (highly concentrated for example) in one compartment, and finally the combination of both. Achieving this first structural step enables us to considerably widen the gap of possibilities in drug delivery systems. Another powerful property of the cell lies in its metabolic function. The second step is therefore to achieve enzymatic reactions in a compartment, as occurs in the organelles, in a highly controlled, selective and efficient manner. We classify the most exciting polymersome nanoreactors reported in our opinion into two different subsections, depending on their very final concept or purpose of design. We also highlight in a thorough table the experimental sections crucial to such work. Finally, after achieving control over these prerequisites, scientists are able to combine them and push the frontiers of biomimicry further: from cell structure mimics towards a controlled biofunctionality. Such a biomimetic approach in material design and the future research it will stimulate, are believed to bring considerable enrichments to the fields of drug delivery, (bio)sensors, (bio)catalysis and (bio)technology.

Polypeptide secondary structure controls the dimensions of aggregates formed from a polybutadiene‐b‐poly(L‐glutamic acid) diblock copolymer after direct dissolution into water. The hydrodynamic radius (RH) of these aggregates (even at high NaCl concentrations) were found to correlate (see picture) with a transition from a compactly folded α‐helical poly(L‐glutamic acid) block at low pH to an extended random coil conformation at basic pH.

Enzyme‐filled polystyrene‐b‐poly(3‐(isocyano‐L‐alanyl‐aminoethyl)thiophene) (PS‐b‐PIAT) nanoreactors are encapsulated together with free enzymes and substrates in a larger polybutadiene‐b‐poly(ethylene oxide) (PB‐b‐PEO) polymersome, forming a multicompartmentalized structure, which shows structural resemblance to the cell and its organelles. An original cofactor‐dependent three‐enzyme cascade reaction is performed, using either compatible or incompatible enzymes, which takes place across multiple compartments.

International audienceHydrophobically modified maghemite (γ-Fe2O3) nanoparticles were encapsulated within the membrane of poly(trimethylene carbonate)-b-poly(L-glutamic acid) (PTMC-b-PGA) block copolymer vesicles using a nanoprecipitation process. This formation method gives a simple access to highly magnetic nanoparticles (MNPs) (loaded up to 70 wt %) together with a good control over the vesicles size (100 to 400 nm). The simultaneous loading of maghemite nanoparticles and doxorubicin was also achieved by nanoprecipitation. The deformation of the vesicle membrane under an applied magnetic field has been evidenced by small angle neutron scattering. These superparamagnetic hybrid self-assemblies display enhanced contrast properties that open potential applications for Magnetic Resonance Imaging. They can also be guided in a magnetic field gradient. The feasibility of controlled drug release by radio-frequency magnetic hyperthermia was demonstrated in the case of encapsulated doxorubicin molecules, showing the viability of the concept of magneto-chemotherapy. These magnetic polymersomes can be used as efficient multifunctional nano-carriers for combined therapy and imaging

Magnetic responsive materials are the topic of intense research due to their potential breakthrough applications in the biomedical, coatings, microfluidics and microelectronics fields. By merging magnetic and polymer materials one can obtain composites with exceptional magnetic responsive features. Magnetic actuation provides unique capabilities as it can be spatially and temporally controlled, and can additionally be operated externally to the system, providing a non-invasive approach to remote control. We identified three classes of magnetic responsive composite materials, according to their activation mode and intended applications, which can be defined by the following aspects. (A) Their ability to be deformed (stretching, bending, rotation) upon exposure to a magnetic field. (B) The possibility of remotely dragging them to a targeted area, called magnetic guidance, which is particularly interesting for biomedical applications, including cell and biomolecule guidance and separation. (C) The opportunity to use magnetic induction for thermoresponsive polymer materials actuation, which has shown promising results for controlled drug release and shape memory devices. For each category, essential design parameters that allow fine-tuning of the properties of these magnetic responsive composites are presented using key examples.

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