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It is important to develop highly efficient and durable Earth-abundant oxygen evolution reaction (OER) electrocatalysts by an energy- and time-saving strategy. Herein, a facile strategy was used to synthesize S-doped nickel-iron oxyhydroxide (S-Ni/FeOOH) nanoparticles on nickel-iron foam (NFF) (S-Ni/FeOOH@NFF), which exhibits a striking enhancement of OER performance compared to Ni/FeOOH@NFF. The free-standing S-Ni/FeOOH@NFF electrode possesses a low overpotential of 229 mV at a current density of 10 mA cm -2 , which is 180 mV lower than that of Ni/FeOOH@NFF. In addition, the electrode was also remarkably stable. The current density still remains at 95% after 150 h at a high current density of 100 mA cm -2 .

A single chain polypeptide containing the low density lipoprotein receptor (LDLR) ligand Seq-1 with blood-brain barrier (BBB) crossing activity has been successfully modified by conventional genetic engineering to self-assemble into stable protein-only nanoparticles of 30nm. The nanoparticulate presentation dramatically enhances in vitro, LDLR-dependent cell penetrability compared to the parental monomeric version, but the assembled protein does not show any enhanced brain targeting upon systemic administration. While the presentation of protein drugs in form of nanoparticles is in general advantageous regarding correct biodistribution, this principle might not apply to brain targeting that is hampered by particular bio-physical barriers. Irrespective of this fact, which is highly relevant to the nanomedicine of central nervous system, engineering the cationic character of defined protein stretches is revealed here as a promising and generic approach to promote the controlled oligomerization of biologically active protein species as still functional, regular nanoparticles., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Biofabrication is attracting interest as a means to produce nanostructured functional materials because of its operational versatility and full scalability. Materials based on proteins are especially appealing, as the structure and functionality of proteins can be adapted by genetic engineering. Furthermore, strategies and tools for protein production have been developed and refined steadily for more than 30 years. However, protein conformation and therefore activity might be sensitive to production conditions. Here, we have explored whether the downstream strategy influences the structure and biological activities, in vitro and in vivo, of a self-assembling, CD44-targeted protein-only nanoparticle produced in Escherichia coli. This has been performed through the comparative analysis of particles built from soluble protein species or protein versions obtained by in vitro protein extraction from inclusion bodies, through mild, non-denaturing procedures. These methods have been developed recently as a convenient alternative to the use of toxic chaotropic agents for protein resolubilization from protein aggregates. The results indicate that the resulting material shows substantial differences in its physicochemical properties and its biological performance at the systems level, and that its building blocks are sensitive to the particular protein source.

The fully de novo design of protein building blocks for self-assembling as functional nanoparticles is a challenging task in emerging nanomedicines, which urgently demand novel, versatile, and biologically safe vehicles for imaging, drug delivery, and gene therapy. While the use of viruses and virus-like particles is limited by severe constraints, the generation of protein-only nanocarriers is progressively reachable by the engineering of protein-protein interactions, resulting in self-assembling functional building blocks. In particular, end-terminal cationic peptides drive the organization of structurally diverse protein species as regular nanosized oligomers, offering promise in the rational engineering of protein self-assembling. However, the in vivo stability of these constructs, being a critical issue for their medical applicability, needs to be assessed. We have explored here if the cross-molecular contacts between protein monomers, generated by end-terminal cationic peptides and oligohistidine tags, are stable enough for the resulting nanoparticles to overcome biological barriers in assembled form. The analyses of renal clearance and biodistribution of several tagged modular proteins reveal long-term architectonic stability, allowing systemic circulation and tissue targeting in form of nanoparticulate material. This observation fully supports the value of the engineered of protein building blocks addressed to the biofabrication of smart, robust, and multifunctional nanoparticles with medical applicability that mimic structure and functional capabilities of viral capsids.

Constructing a heterostructure is an efficient strategy to enhance the catalytic activity toward the oxygen evolution reaction (OER). Herein, Ce-modified Ni(OH)2 nanoparticles are anchored on Ni-MOF nanosheets by the electrodeposition strategy, forming a self-supporting electrode of Ce-m-Ni(OH)2@Ni-MOF. The Raman spectrum proves that both Ce(OH)3 and Ce doping exist in Ce-modified Ni(OH)2 nanoparticles. The heterostructure possesses an open nanosheet structure, with a good interaction between Ni-MOF and Ce-m-Ni(OH)2, which enables efficient mass/charge transfer and the synergetic effect between Ni and Ce, leading to a high-performance electrocatalyst. Specifically, Ce-m-Ni(OH)2@Ni-MOF achieves current densities of 50 and 100 mA cm−2 at low overpotentials of 219 and 272 mV, respectively, and retains high activity for at least 30 h. [ABSTRACT FROM AUTHOR]

A single chain polypeptide containing the low density lipoprotein receptor (LDLR) ligand Seq-1 with blood–brain barrier (BBB) crossing activity has been successfully modified by conventional genetic engineering to self-assemble into stable protein-only nanoparticles of 30 nm. The nanoparticulate presentation dramatically enhances in vitro , LDLR-dependent cell penetrability compared to the parental monomeric version, but the assembled protein does not show any enhanced brain targeting upon systemic administration. While the presentation of protein drugs in form of nanoparticles is in general advantageous regarding correct biodistribution, this principle might not apply to brain targeting that is hampered by particular bio-physical barriers. Irrespective of this fact, which is highly relevant to the nanomedicine of central nervous system, engineering the cationic character of defined protein stretches is revealed here as a promising and generic approach to promote the controlled oligomerization of biologically active protein species as still functional, regular nanoparticles. [ABSTRACT FROM AUTHOR]

Homing peptides are exploited in nanomedicine to functionalize either free drugs or nanostructured materials used as drug carriers. However, the influence of multivalent versus monovalent peptide presentation on the interaction with the receptor and on the consequent intracellular delivery of the associated cargo remains poorly explored. By using a tumor-homing peptide (T22) with regulatable self-assembling properties we have investigated here if its display in a either a monomeric form or as multimeric, self-assembled protein nanoparticles might determine the efficacy of receptor-mediated penetrability into target cells. This has been monitored by using a fluorescent cargo protein (iRFP), which when fused to the homing peptide acts as convenient reporter. The results indicate that the nanoparticulate protein versions are significantly more efficient in mediating receptor-dependent uptake than their unassembled counterparts. These finding stresses an additional benefit of nanostructured materials based on repetitive building blocks, regarding the multivalent presentation of cell ligands that facilitate cell penetration in drug delivery applications . [ABSTRACT FROM AUTHOR]

Highlights: [•] A series of BiOIαCl1-α solid solution electrode were successfully prepared through a simple electrodeposition method. [•] All prepared BiOIαCl1-α electrodes exhibited p-type conductivity. [•] The BiOIαCl1-α solid solution showed the best photoelectrochemical activity at α =0.5. [Copyright &y& Elsevier]

The increasing incidence of diseases affecting the central nervous system (CNS) demands the urgent development of efficient drugs. While many of these medicines are already available, the Blood Brain Barrier and to a lesser extent, the Blood Spinal Cord Barrier pose physical and biological limitations to their diffusion to reach target tissues. Therefore, efforts are needed not only to address drug development but specially to design suitable vehicles for delivery into the CNS through systemic administration. In the context of the functional and structural versatility of proteins, recent advances in their biological fabrication and a better comprehension of the physiology of the CNS offer a plethora of opportunities for the construction and tailoring of plain nanoconjugates and of more complex nanosized vehicles able to cross these barriers. We revise here how the engineering of functional proteins offers drug delivery tools for specific CNS diseases and more transversally, how proteins can be engineered into smart nanoparticles or ‘artificial viruses’ to afford therapeutic requirements through alternative administration routes. [ABSTRACT FROM AUTHOR]