The ins and outs of nanoparticle technology in neurodegenerative diseases and cancer.

As we enter the twenty-first century, several therapies based on using nanoparticles (NPs) ranging in size 1 - 1000 nm have been successfully brought to the clinic to treat cancer, pain and infectious diseases. These therapies bring together the ability of NPs to target the delivery of drugs more precisely, to improve solubility, to prevent degradation, to improve their therapeutic index and to reduce the immune response. NPs come in all shapes and sizes, designed specifically for biomedical applications such as solid lipid polymers, liposomes, dendrimers, nanogels, and quantum dots. These NPs offer many attractive characteristics such as biological stability and biocompatibility, thus incorporating different biological or drug molecules. Among the major therapeutic challenges from neurological diseases through to cancer is the development of nanomaterials that are able to be effective against the disease. In the case of neurodegeneration, one of the most difficult areas to penetrate for drug discovery in the body is the central nervous system, protected by the blood-brain-barrier. Whilst in the case of cancer, the biggest problem is how to specifically target a tumor with sufficient drug without causing side effects or inducing resistance. A new generation of intelligent NPs are emerging for the treatment of human disease such as neurological disorders and cancer. The use of natural alternative therapy is an encouraging idea in drug discovery. To this end as we gain more knowledge into the biological function of exosomes, this will allow us to harness their potential as natural NPs in future therapeutics

Development of multisubstituted hydroxyapatite nanopowders as biomedical materials for bone tissue engineering applications

Ionic substitutions have been proposed as a tool to control the functional behavior of synthetic hydroxyapatite (HA), particularly for Bone Tissue Engineering applications. The effect of simultaneous substitution of different levels of carbonate (CO3) and silicon (Si) ions in the HA lattice was investigated. Furthermore, human bone marrow‐derived mesenchymal stem cells (hMSCs) were cultured on multi‐substituted HA (SiCHA) to determine if biomimetic chemical compositions were osteoconductive. Of the four different compositions investigates, SiCHA‐1 (0.58 wt % Si) and SiCHA‐2 (0.45 wt % Si) showed missing bands for CO3 and Si using FTIR analysis, indicating competition for occupation of the phosphate site in the HA lattice; 500°C was considered the most favorable calcination temperature as: (i) the powders produced possessed a similar amount of CO3 (2–8 wt %) and Si (<1.0 wt %) as present in native bone; and (ii) there was a minimal loss of CO3 and Si from the HA structure to the surroundings during calcination. Higher Si content in SiCHA‐1 led to lower cell viability and at most hindered proliferation, but no toxicity effect occurred. While, lower Si content in SiCHA‐2 showed the highest ALP/DNA ratio after 21 days culture with hMSCs, indicating that the powder may stimulate osteogenic behavior to a greater extent than other powder

Synthesis by solid route and physicochemical characterizations of blends of calcium orthophosphate powders and mesoporous silicon particles

The purpose of the study was to investigate the synthesis of economic calcium phosphate powders from recycled oyster shells, using a ball milling method. The oyster shell powder and a calcium pyrophosphate powder were used as starting materials and ball milled, then heat treated at 1,050°C for 5 h to produce calcium phosphate powders through a solid-state reaction. Electrochemically synthesized mesoporous silicon microparticles were then added to the prepared phosphate powders by mechanical mixer. The final powders were characterized using X-ray diffraction, Fourier transform infrared spectroscopy, and scanning electron microscopy to analyze their chemical composition and determine the most suitable process conditions. The biocompatibility of the produced powders was also tested in vitro using murine cells and the results showed good biocompatibility

Développement de céramiques pour l'ingénierie tissulaire osseuse : de la synthèse de matériaux à l’évaluation biologique

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Calcium phosphate bioceramics: From cell behavior to chemical-physical properties

International audienceCalcium phosphate ceramics, including hydroxyapatite (HA), have been used as bone substitutes for more than 40 years. Their chemical composition, close to that of the bone mineral, confers them good biological and physical properties. However, they are not sufficient to meet all the needs in bone regenerative medicine, such as in the context of critical bone lesions. Therefore, it is essential to improve their biological performances in order to extend their application domains. In this aim, three approaches are mainly followed on the assumption that the biological response can be tuned by modifications of the chemical physical properties of the ceramic: 1) Incorporation of specific chemical species into the calcium phosphate crystalline lattice of chemical elements to stimulate bone repair. 2) Modulation of the bioceramic architecture to optimize the cellular responses at the interface. 3) Functionalization of the bioceramic surface with bioactive molecules. These approaches are supposed to act on separate parameters but, as they are implemented during different steps of the ceramic processing route, they cannot be considered as exclusive. They will ineluctably induces changes of several other physical chemical properties of the final ceramic that may also affect the biological response. Using examples of recent works from our laboratory, the present paper aims to describe how biology can be affected by the bioceramics modifications according to each one of these approaches. It shows that linking biological and chemical physical data in a rational way makes it possible to identify pertinent parameters and related processing levers to target a desired biological response and then more precisely tune the biological performance of ceramic biomaterials. This highlights the importance of integrating the biological evaluation into the heart of the processes used to manufacture optimized biomaterials

Stomatodynie et cannabis

Les stomatodynies sont des douleurs chroniques donnant des sensations de brûlures des muqueuses buccales sans lésion biologique/ clinique ou radiologique. Elles concernent majoritairement les femmes ménopausées. Ces douleurs sont sous-tendues par un mécanisme neuropathique, non élucidé encore, altérant les fonctions sensorielles centrales et/ ou périphériques. Afin de soulager les patients, de nombreuses thérapeutiques sont tentées (antidépresseurs tricycliques, gabapentinoïdes, dérivés morphiniques, anesthésiques locaux) mais les résultats sont souvent décevants et les rémissions rares. Motivé par le cas d’une patiente stomatodynique chez qui l’inhalation de cannabis a provoqué la disparition des symptômes douloureux, nous décrivons, dans ce travail, les mécanismes d’action des cannabinoïdes. En se liant, notamment, aux récepteurs cannabinoïdes CB1 et CB2 mais aussi au récepteur vanilloïde TRPV1, les cannabinoïdes et les endocannabinoïdes (produits par notre organisme) sont capables d’atténuer l’hyperalgésie et l’allodynie thermiques dans le cadre de douleurs chroniques orofaciales. Ces résultats constituent un espoir thérapeutique pour les patients atteints de stomatodynie chez qui une altération du système endocannabinoïde est observée. Ainsi, l’augmentation des taux d’endocannabinoïdes ou l’administration des cannabinoïdes exogènes font partie des pistes thérapeutiques potentielles

La transdisciplinarité au service de la conception d’implants innovants éphémères

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Des matériaux céramiques pour réparer l’os : Comprendre l’interaction des cellules avec leur environnement pour créer des substituts osseux innovants

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