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Herein novel multicompartment nanoparticles (MCNs) that combine high stability and cargo loading capacity are developed. The MCNs are fabricated by crystallization-driven self-assembly (CDSA) of a tailor-made 21 arm star polymer, poly(L-lactide)[poly(tert-butyl acrylate)-block-poly(ethylene glycol)] 20 [PLLA(PtBA-b-PEG) 20 ]. Platelet-like or spherical MCNs containing a crystalline PLLA core and hydrophobic PtBA subdomains are formed and stabilized by PEG. Hydrophobic cargos, such as Nile Red and chemotherapeutic drug doxorubicin, can be successfully encapsulated into the collapsed PtBA subdomains with loading capacity two orders of magnitude higher than traditional CDSA nanoparticles. Depolarized fluorescence measurements of the Nile Red loaded MCNs suggest that the free volume of the hydrophobic chains in the nanoparticles may be the key for regulating their drug loading capacity. In vitro study of the MCNs suggests excellent cytocompatibility of the blank nanoparticles as well as a dose-dependent cellular uptake and cytotoxicity of the drug-loaded MCNs., (© 2022 Wiley-VCH GmbH.)

Interactive materials that can respond to a trigger by changing their morphology, but that can also gradually degrade into a fully soluble state, are attractive building blocks for the next generation of biomaterials. Herein, we design such transiently responsive polymers that exhibit UCST behaviour while gradually losing this property in response to a hydrolysis reaction in the polymer side chains. The polymers operate within a physiologically relevant window in terms of temperature, pH, and ionic strength. Whereas such behaviour has been reported earlier for LCST systems, it is at present unexplored for UCST polymers. Furthermore, we demonstrate that, in contrast to LCST polymers, in aqueous medium the UCST polymer forms a coacervate phase below the UCST, which can entrap a hydrophilic model protein, as well as a hydrophobic dye. Because of their non-toxicity, we also provide in vivo proof of concept of the use of this coacervate as a protein depot, in view of sustained-release applications., (© 2019 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Interactive materials that can respond to a trigger by changing their morphology, but that can also gradually degrade into a fully soluble state, are attractive building blocks for the next generation of biomaterials. Herein, we design such transiently responsive polymers that exhibit UCST behaviour while gradually losing this property in response to a hydrolysis reaction in the polymer side chains. The polymers operate within a physiologically relevant window in terms of temperature, pH, and ionic strength. Whereas such behaviour has been reported earlier for LCST systems, it is at present unexplored for UCST polymers. Furthermore, we demonstrate that, in contrast to LCST polymers, in aqueous medium the UCST polymer forms a coacervate phase below the UCST, which can entrap a hydrophilic model protein, as well as a hydrophobic dye. Because of their non‐toxicity, we also provide in vivo proof of concept of the use of this coacervate as a protein depot, in view of sustained‐release applications. [ABSTRACT FROM AUTHOR]

Here we report on a simple, generally applicable method for depositing metal nanoparticles on a wide variety of solid surfaces under all aqueous conditions. Noble-metal nanoparticles obtained by citrate reduction followed by coating with thermoresponsive polymers spontaneously form a monolayer-like structure on a wide variety of substrates in presence of sodium chloride whereas this phenomenon does not occur in salt-free medium. Interestingly, this phenomenon occurs below the cloud point temperature of the polymers and we hypothesize that salt ion-induced screening of electrostatic charges on the nanoparticle surface entropically favors hydrophobic association between the polymer-coated nanoparticles and a hydrophobic substrate. [ABSTRACT FROM AUTHOR]

It is demonstrated how cellular uptake and protein corona of (co)polymer-coated gold nanoparticles can be altered by the hydrophilic-to-hydrophobic comonomer ratio. A novel, label-free flow cytometry strategy is developed to investigate particle uptake. These findings offer insight in the design and analysis of hybrid nanomaterials for interfacing with biological systems. [ABSTRACT FROM AUTHOR]

Nanoporous microparticles are produced in a single step based on hydrogen bonding between a neutral polymer and tannic acid. These particles are stable in physiological medium, are non-toxic to in vitro cultured cells, and can efficiently encapsulate proteins. In vitro and in vivo experiments show that these porous hydrogen bonded microparticles are able to induce antigen-specific cellular and humoral immune responses against encapsulated vaccine antigens. Considering the easy and low cost manufacturing of this dry powder formulation from approved readily available components, it is anticipated that this technology holds great promise for the formulation of vaccines for developing countries or for pandemic vaccines where long term storage under refrigerated conditions is a major issue. Additionally, due to the versatility of the approach facilitates straightforward co-encapsulation of a wide variety of additional components to further modulate the immune response. [ABSTRACT FROM AUTHOR]

Wereport that the aqueous self-assembly behavior of citrate basedgold nanoparticles decorated with the temperature responsive RAFT-basedpolymer poly(N-isopropylacrylamide) critically dependson the presence of salt in the medium. Both for temperature inducedreversible agglomeration and for hydrogen bonding based layer-by-layerassembly with tannic acid, the presence of salt dramatically promotesthe assembly behavior. We attribute this to a combination of ionicscreening of the remaining citrate groups on the nanoparticle surfaceand a salting out effect which increases the contribution of hydrophobicinteractions in the self-assembly process. These findings providenew insights into an attractive class of polymer/gold hybrid nanomaterialsthat can find application in biotechnology, catalysis, and biomedicine. [ABSTRACT FROM AUTHOR]