Peptides to Overcome the Limitations of Current Anticancer and Antimicrobial Nanotherapies

Biomedical research devotes a huge effort to the development of efficient non-viral nanovectors (NV) to improve the effectiveness of standard therapies. NVs should be stable, sustainable and biocompatible and enable controlled and targeted delivery of drugs. With the aim to foster the advancements of such devices, this review reports some recent results applicable to treat two types of pathologies, cancer and microbial infections, aiming to provide guidance in the overall design of personalized nanomedicines and highlight the key role played by peptides in this field. Additionally, future challenges and potential perspectives are illustrated, in the hope of accelerating the translational advances of nanomedicine

Formation of miRNA Nanoprobes—Conjugation Approaches Leading to the Functionalization

International audienceRecently, microRNAs (miRNA) captured the interest as novel diagnostic and prognostic biomarkers, with their potential for early indication of numerous pathologies. Since miRNA is a short, non-coding RNA sequence, the sensitivity and selectivity of their detection remain a cornerstone of scientific research. As such, methods based on nanomaterials have emerged in hopes of developing fast and facile approaches. At the core of the detection method based on nanotechnology lie nanoprobes and other functionalized nanomaterials. Since miRNA sensing and detection are generally rooted in the capture of target miRNA with the complementary sequence of oligonucleotides, the sequence needs to be attached to the nanomaterial with a specific conjugation strategy. As each nanomaterial has its unique properties, and each conjugation approach presents its drawbacks and advantages, this review offers a condensed overview of the conjugation approaches in nanomaterial-based miRNA sensing. Starting with a brief recapitulation of specific properties and characteristics of nanomaterials that can be used as a substrate, the focus is then centered on covalent and non-covalent bonding chemistry, leading to the functionalization of the nanomaterials, which are the most commonly used in miRNA sensing methods

Two-step formulation of magnetic nanoprobes for microRNA capture

International audienceMicroRNAs (miRs) belong to a family of short non-coding endogenous RNAs. Their over-expression correlates with various pathologies: for instance, miRNA-155 (miR-155) is over-expressed upon the development of breast cancers. However, the detection of miRs as disease biomarkers suffers from insufficient sensitivity. In the present study, we propose a protocol for a rapid and efficient generation of magnetic nanoprobes able to capture miR-155, with the aim of increasing its concentration. As a nanoprobe precursor, we first synthesized superparamagnetic iron oxide nanoparticles (SPIONs) coated with covalently attached polyethylene glycol carrying a free biotin terminus (PEG-bi). Using streptavidin–biotin interactions, the nanoprobes were formulated by functionalizing the surface of the nanoparticles with the miR sequence (CmiR) complementary to the target miR-155 (TmiR). The two-step formulation was optimized and validated using several analytical techniques, in particular with Size-Exclusion High Performance Liquid Chromatography (SE-HPLC). Finally, the proof of the nanoprobe affinity to TmiR was made by demonstrating the TmiR capture on model solutions, with the estimated ratio of 18 : 22 TmiR : CmiR per nanoprobe. The nanoprobes were confirmed to be stable after incubation in serum

Nanomedicines functionalized with anti-EGFR ligands for active targeting in cancer therapy: Biological strategy, design and quality control

International audienceRecently, active targeting using nanocarriers with biological ligands has emerged as a novel strategy for improving the delivery of therapeutic and/or imaging agents to tumor cells. The presence of active targeting moieties on the surface of nanomedicines has been shown to play an important role in enhancing their accumulation in tumoral cells and tissues versus healthy ones. This property not only helps to increase the therapeutic index but also to minimize possible side effects of the designed nanocarriers. Since the overexpression of epidermal growth factor receptors (EGFR) is a common occurrence linked to the progression of a broad variety of cancers, the potential application of anti-EGFR immunotherapy and EGFR-targeting ligands in active targeting nanomedicines is getting increasing attention. Henceforth, the EGFR-targeted nanomedicines were extensively studied in vitro and in vivo but exhibited both satisfactory and disappointing results, depending on used protocols. This review is designed to give an overview of a variety of EGFR-targeting ligands available for nanomedicines, how to conjugate them onto the surface of nanoparticles, and the main analytical methods to confirm this successful conjugation

Stealth magnetic nanocarriers of siRNA as platform for breast cancer theranostics

International audienceThe endogenous mechanism of RNA interference is more and more used in research to obtain specific down-regulation of gene expression in diseases such as breast cancer. Currently, despite the new fields of study open up by RNA interference, the rapid degradation of siRNA by nucleases and their negative charges prevent them from crossing cell membranes. To overcome these limitations, superparamagnetic iron oxide nanoparticles (SPIONs) represent a promising alternative for nucleic acid delivery. Previously, we reported the magnetic siRNA nanovectors (MSN) formulation using electrostatic assembly of (1) SPIONs, also able to act as contrast agents for magnetic resonance imaging (MRI), (2) siRNA and (3) chitosan aiming at their protection and enhancing their transfection efficacy. However, these nanoparticles displayed low stability in biological suspensions and inefficient transfection of active siRNA.This work aimed at upgrading MSN to Stealth MSN (S-MSN) by adding a polyethylene glycol coating to ensure colloidal stability and stealth properties. Furthermore, another polymer (poly-L-arginine) was added for efficient siRNA transfection and the quantitative composition of the formulation was adapted for biological purposes. Results showed that S-MSN provide high siRNA complexation and protection against enzymatic degradation. Green fluorescent protein (GFP) specific down-regulation on MDA-MB231/GFP cells was comparable to that of commercially available reagents, without observable cytotoxicity. According to our works, S-MSN appears as an effective formulation for in vitro siRNA specific delivery

Polyethylene-glycol-Stabilized Ag Nanoparticles for Surface-Enhanced Raman Scattering Spectroscopy: Ag Surface Accessibility Studied Using Metalation of Free-Base Porphyrins

International audienceSilver nanoparticles (Ag NPs) stabilized with a permeable layer of long-chain polyethylene glycol (PEG) represent a new generation of surface-enhanced Raman scattering (SERS) substrates for bioanalytical applications. This paper will shed light on their efficiency in the SERS detection of biomolecules. Two types of thiol-terminated PEG (average molecular weight 5000 g/mol) were used. Metalation of free-base porphyrins (10–9–10–6 M) of different size and charge was employed as the probe of accessibility of the Ag-PEG NP surface. The influence of NaCl (0.01 M) on the system was examined. The metalation was significantly decreased by the interaction of porphyrins with propionylamino groups of PEG1, while no interaction with the neutral chain of PEG2 was observed. Sterical hindrance of the porphyrin side groups seemed to cause a rather perpendicular porphyrin orientation on both types of Ag-PEG NP surfaces, inhibiting the metalation. Moreover, chloride anions influenced the structure of the polymer coating and improved the porphyrin accessibility on the Ag-PEG1 NPs. Finally, the studied Ag-PEG NPs remained isolated even after addition of porphyrins and chlorides, therefore being favorable for SERS applications inside the living cells

Active targeting strategy in nanomedicines using anti-EGFR ligands - a promising approach for cancer therapy and diagnosis

International audienceAs active targeting using nanomedicines establishes itself as a strategy of choice in cancer therapy, several target receptors or ligands overexpressed in cancer cells have been identified and exploited. Among them, the epidermal growth factor receptor (EGFR) has emerged as one of the most promising oncomarkers for active targeting nanomedicines due to its overexpression and its active involvement in a wide range of cancer types. Henceforth, many novel EGFR-targeted nanomedicines for cancer therapy have been developed, giving encouraging results both in vitro and in vivo. This review focuses on different applications of such medicines in oncotherapy. On an important note, the contribution of EGFR-targeting ligands to final therapy efficacy along with current challenges and possible solutions or alternatives are emphasized

Design strategies of hybrid metallic nanoparticles for theragnostic applications.

International audienceMetallic nanoparticles (MNPs) such as iron oxide and gold nanoparticles are interesting platforms to build theragnostic nanocarriers which combine both therapeutic and diagnostic functions within a single nanostructure. Nevertheless, their surface must be functionalized to be suitable for in vivo applications. Surface functionalization also provides binding sites for targeting ligands, and for drug loading. This review focuses on the materials and surface chemistry used to build hybrid nanocarriers that are inorganic cores functionalized with organic materials. The surface state of the MNPs largely depends on their synthesis routes, and dictates the strategies used for functionalization. Two main strategies can be found in the literature: the design of core-shell nanosystems, or embedding nanoparticles in organic materials. Emerging tendencies such as the use of clusters or alternative coating materials are also described. To present both hydrophilic and lipophilic nanosystems, we chose the doxorubicin anticancer agent as an example, as the molecule presents an affinity for both types of materials

Use of experimental design methodology for the development of new magnetic siRNA nanovectors (MSN).

International audienceShort interfering RNAs (siRNAs) can downregulate the synthesis of proteins and thus be used to treat certain diseases where the protein synthesis is upregulated, such as cancer. The challenge is to deliver siRNAs in the target cell as they are rapidly degraded by nucleases and have difficulties to cross the cellular membranes. Superparamagnetic iron oxide nanoparticles (SPIONs) are widely studied as platforms for smart biocompatible nanosystems which can be used for magnetic drug targeting and magnetic resonance imaging. The aim of this work was to combine siRNAs, SPIONs, and chitosan, to develop new magnetic siRNA nanovectors suitable for systemic administration. In a first time, the one factor at a time (OFAT) methodology was used to adjust different formulation parameters and to test the feasibility of such a formulation. In a second time, design of experiment (DOE) methodology was used to analyze the influence of these formulation parameters on the physicochemical characteristics hydrodynamic diameter (DH) and ζ-potential. Finally, four MSNs suitable for systemic administration could be identified using the OFAT method. The DOE method showed a significant effect of CR and [NaNO3] on the DH and a significant effect of MR and [siRNA] on the ζ-potential of the nanocarriers

Nanomédecines fonctionnalisées par un scfv anti-EGFR pour le ciblage actif des cellules de cancer du sein triple négatif

poster + "pitch" présentation du poster en 90 sContexte: Les nanovecteurs magnétiques à base de nanoparticules d’oxydes de fer superparamagnétiques (SPIONs) apparaissent comme un système prometteur pour l’administration ciblée de médicaments (1) et comme agents d’imagerie (2). On parle alors de nanomédecines (NM) théranostiques. Le ciblage des tumeurs à l’aide des NM peut-être amélioré par le greffage de ligands biologiques comme des fragments d’anticorps de type scFv (single chain variable fragment) (3). Pour le diagnostic, les NM peuvent être utilisés en tant qu’agents de contraste en imagerie par résonance magnétique (IRM) ou détectées en imagerie de fluorescence grâce au couplage d’un fluorochrome proche infrarouge (fluoPIR) à la surface. Il est également possible de complexer des polyplexes sur les NM permettant ainsi la delivrance intracellulaire ciblée de siRNA. Cette étude porte sur l’évaluation de ces NM fonctionnalisés avec un scFv anti-EGFR (Epidermal Growth Factor Receptor) pour le ciblage actif du cancer du sein triple négatif (CSTN) et l’impact de la modification de la couche polymérique sur l’interaction de ces NM avec les cellules cancéreuses.Résultats :Grâce au couplage par scFv anti-EGFR, les NM ont montré une bonne affinité et un spécifique ciblage des cellules de CSTN (lignée MDA-MB231). En effet, la pénétration dans les cellules correspondantes des NM ciblées est 4 et 6 fois plus élevée que les NM sans scFv à 4 heures et 24 heures d’incubation respectivement. En augmentant la couche de polymère en surface des NM, nous démontrons une diminuation de la pénétration cellulaire de ces NM sans l’agent de ciblage, cette réduction étant ensuite gommée suite au greffage de l’agent de ciblage. Les SPIONs-PEG entre mieux dans les cellules cancéreuses que les SPIONs-2xPEG mais au contraire les SPIONs-PEG-scFv entre moins bien que les SPIONs-2xPEG-scFv au même temps d’incubation. De plus, l’accroissement de la couche de polymère ne perturbe pas la complexation entre les NM et les siRNA car les propriétés physico-chimiques mesurées restent très semblables.Conclusions : Cette étude montre que les NM fonctionnalisées par scFv anti-EGFR sont prometteurs pour le ciblage actif du cancer du sein triple négatif