Editorial: High added-value nanoparticles: Rethinking and recycling cell protein waste

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Editorial: High added-value nanoparticles: Rethinking and recycling cell protein waste

Extracellular vesicles; Biomedicine; NanobiotechnlogyVesículas extracelulares; Biomedicina; NanobiotecnologíaVesícules extracel·lulars; Biomedicina; Nanobiotecnologi

Protein features instruct the secretion dynamics from metal-supported synthetic amyloids

Hexahistidine-tagged proteins can be clustered by divalent cations into self-containing, dynamic protein depots at the microscale, which under physiological conditions leak functional protein. While such protein granules show promise in clinics as time-sustained drug delivery systems, little is known about how the nature of their components, that is, the protein and the particular cation used as cross-linker, impact on the disintegration of the material and on its secretory performance. By using four model proteins and four different cation formulations to control aggregation, we have here determined a moderate influence of the used cation and a potent impact of some protein properties on the release kinetics and on the final fraction of releasable protein. In particular, the electrostatic charge at the amino terminus and the instability and hydropathicity indexes determine the disintegration profile of the depot. These data offer clues for the fabrication of efficient and fully exploitable secretory granulesthat being biocompatible and chemically homogenous allow their tailored use as drug delivery platforms in biological systems

Selecting subpopulations of high-quality protein conformers among conformational mixtures of recombinant bovine MMP-9 solubilized from inclusion bodies

Altres ajuts: CERCA Programme/Generalitat de CatalunyaA detailed workflow to analyze the physicochemical characteristics of mammalian matrix metalloproteinase (MMP-9) protein species obtained from protein aggregates (inclusion bodies-IBs) was followed. MMP-9 was recombinantly produced in the prokaryotic microbial cell factories Clearcoli (an engineered form of Escherichia coli) and Lactococcus lactis, mainly forming part of IBs and partially recovered under non-denaturing conditions. After the purification by affinity chromatography of solubilized MMP-9, four protein peaks were obtained. However, so far, the different conformational protein species forming part of IBs have not been isolated and characterized. Therefore, with the aim to link the physicochemical characteristics of the isolated peaks with their biological activity, we set up a methodological approach that included dynamic light scattering (DLS), circular dichroism (CD), and spectrofluorometric analysis confirming the separation of subpopulations of conformers with specific characteristics. In protein purification procedures, the detailed analysis of the individual physicochemical properties and the biological activity of protein peaks separated by chromatographic techniques is a reliable source of information to select the best-fitted protein populations

Recombinant Leishmania infantum heat shock protein 83 for the serodiagnosis of cutaneous, mucosal, and visceral lieshmaniases

Routine serological diagnoses for leishmaniases, except in visceral cases, are performed using wholeparasite\ud antigens. We used enzyme-linked immunosorbent assay (ELISA) to evaluate the performance of Leishmania\ud infantum rHsp83 compared with L. major-like total promastigote antigen in the diagnosis of cutaneous (CL), mucosal\ud (ML), and visceral leishmaniases (VL). ELISA-rHsp83 was significantly more sensitive than ELISA–L. major-like when\ud considering either CL/ML (P = 0.041) or all leishmaniasis patients (P = 0.013). When samples from other infectious\ud disease patients were evaluated for cross-reactivity, ELISA-rHsp83 was more specific than ELISA–L. major-like,\ud specifically for Chagas disease samples (P < 0.001). We also evaluated the anti-rHsp83 antibody titers months after\ud treatment and observed no significant difference in ML (P = 0.607) or CL (P = 0.205). We recommend ELISA–L.\ud infantum-rHsp83 as a routine confirmatory serological assay for the diagnosis of Leishmania infection because of the high sensitivity, the specificity, and the insignificant cross-reactivity with other infectious diseases.Financial support: This work was supported by Fundação de Amparo à Pesquisa do Estado de São Paulo (2011/02235-0), Conselho Nacional de Pesquisa (CNPq; research fellowship; to H.G.), Instituto Nacional de Ciência e Tecnologia-CNPq-Nanotecnologia para Marcadores Integrados, and Laboratório de Investigação Médica-38/Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo

In Vivo Bactericidal Efficacy of GWH1 Antimicrobial Peptide Displayed on Protein Nanoparticles, a Potential Alternative to Antibiotics

Oligomerization of antimicrobial peptides into nanosized supramolecular complexes produced in biological systems (inclusion bodies and self-assembling nanoparticles) seems an appealing alternative to conventional antibiotics. In this work, the antimicrobial peptide, GWH1, was N-terminally fused to two different scaffold proteins, namely, GFP and IFN-γ for its bacterial production in the form of such recombinant protein complexes. Protein self-assembling as regular soluble protein nanoparticles was achieved in the case of GWH1-GFP, while oligomerization into bacterial inclusion bodies was reached in both constructions. Among all these types of therapeutic proteins, protein nanoparticles of GWH1-GFP showed the highest bactericidal effect in an in vitro assay against Escherichia coli, whereas non-oligomerized GWH1-GFP and GWH1-IFN-γ only displayed a moderate bactericidal activity. These results indicate that the biological activity of GWH1 is specifically enhanced in the form of regular multi-display configurations. Those in vitro observations were fully validated against a bacterial infection using a mouse mastitis model, in which the GWH1-GFP soluble nanoparticles were able to effectively reduce bacterial loads

The spectrum of building block conformers sustains the biophysical properties of clinically-oriented self-assembling protein nanoparticles

Altres ajuts: Acord transformatiu CRUE-CSICHistidine-rich peptides confer self-assembling properties to recombinant proteins through the supramolecular coordination with divalent cations. This fact allows the cost-effective, large-scale generation of microscopic and macroscopic protein materials with intriguing biomedical properties. Among such materials, resulting from the simple bioproduction of protein building blocks, homomeric nanoparticles are of special value as multivalent interactors and drug carriers. Interestingly, we have here identified that the assembly of a given His-tagged protein might render distinguishable categories of self-assembling protein nanoparticles. This fact has been scrutinized through the nanobody-containing fusion proteins EM1-GFP-H6 and A3C8-GFP-H6, whose biosynthesis results in two distinguishable populations of building blocks. In one of them, the assembling and disassembling is controllable by cations. However, a second population immediately self-assembles upon purification through a non-regulatable pathway, rendering larger nanoparticles with specific biological properties. The structural analyses of both model proteins and nanoparticles revealed important conformational variability in the building blocks. This fact renders different structural and functional categories of the final soft materials resulting from the participation of energetically unstable intermediates in the oligomerization process. These data illustrate the complexity of the His-mediated protein assembling in recombinant proteins but they also offer clues for a better design and refinement of protein-based nanomedicines, which, resulting from biological fabrication, show an architectonic flexibility unusual among biomaterials

Recruiting potent membrane penetrability in tumor cell-targeted protein-only nanoparticles

Altres ajuts: Marató de TV3 foundation (TV32013-3930 i TV32013-2030) i ICREA Academia awardThe membrane pore-forming activities of the antimicrobial peptide GWH1 have been evaluated in combination with the CXCR4-binding properties of the peptide T22, in self-assembling protein nanoparticles with high clinical potential. The resulting materials, of 25 nm in size and with regular morphologies, show a dramatically improved cell penetrability into CXCR4 cells (more than 10-fold) and enhanced endosomal escape (the lysosomal degradation dropping from 90% to 50%), when compared with equivalent protein nanoparticles lacking GWH1. These data reveal that GWH1 retains its potent membrane activity in form of nanostructured protein complexes. On the other hand, the specificity of T22 in the CXCR4 receptor binding is subsequently minimized but, unexpectedly, not abolished by the presence of the antimicrobial peptide. The functional combination T22-GWH1 results in 30% of the nanoparticles entering cells via CXCR4 while also exploiting pore-based uptake. Such functional materials are capable to selectively deliver highly potent cytotoxic drugs upon chemical conjugation, promoting CXCR4-dependent cell death. These data support the further development of GWH1-empowered cell-targeted proteins as nanoscale drug carriers for precision medicines. This is a very promising approach to overcome lysosomal degradation of protein nanostructured materials with therapeutic value

Artificial inclusion bodies for clinical development

Bacterial inclusion bodies (IBs) are mechanically stable protein particles in the microscale, which behave as robust, slow-protein-releasing amyloids. Upon exposure to cultured cells or upon subcutaneous or intratumor injection, these protein materials secrete functional IB polypeptides, functionally mimicking the endocrine release of peptide hormones from secretory amyloid granules. Being appealing as delivery systems for prolonged protein drug release, the development of IBs toward clinical applications is, however, severely constrained by their bacterial origin and by the undefined and protein-to-protein, batch-to-batch variable composition. In this context, the de novo fabrication of artificial IBs (ArtIBs) by simple, cell-free physicochemical methods, using pure components at defined amounts is proposed here. By this, the resulting functional protein microparticles are intriguing, chemically defined biomimetic materials that replicate relevant functionalities of natural IBs, including mammalian cell penetration and local or remote release of functional ArtIB-forming protein. In default of severe regulatory issues, the concept of ArtIBs is proposed as a novel exploitable category of biomaterials for biotechnological and biomedical applications, resulting from simple fabrication and envisaging soft developmental routes to clinic

Nanostructure empowers active tumor targeting in ligand-based molecular delivery

Altres ajuts: to EU COST Action CA 17140 and ICREA AcademiaCell-selective targeting is expected to enhance effectiveness and minimize side effects of cytotoxic agents. Functionalization of drugs or drug nanoconjugates with specific cell ligands allows receptor-mediated selective cell delivery. However, it is unclear whether the incorporation of an efficient ligand into a drug vehicle is sufficient to ensure proper biodistribution upon systemic administration, and also at which extent biophysical properties of the vehicle may contribute to the accumulation in target tissues during active targeting. To approach this issue, structural robustness of self-assembling, protein-only nanoparticles targeted to the tumoral marker CXCR4 is compromised by reducing the number of histidine residues (from six to five) in a histidine-based architectonic tag. Thus, the structure of the resulting nanoparticles, but not of building blocks, is weakened. Upon intravenous injection in animal models of human CXCR4 colorectal cancer, the administered material loses the ability to accumulate in tumor tissue, where it is only transiently found. It instead deposits in kidney and liver. Therefore, precise cell-targeted delivery requires not only the incorporation of a proper ligand that promotes receptor-mediated internalization, but also, unexpectedly, its maintenance of a stable multimeric nanostructure that ensures high ligand exposure and long residence time in tumor tissue