Green chitosan extraction from Hermetia illucens waste breeding (prepupal cases): Characterization and bioadsorption activity

International audienceHeavy metal contamination has harmful consequences for the ecosystem. They are naturally non-biodegradable, and can cause severe ecotoxicity and numerous pathologies. Several bioadsorbents have been used for metal pollution control, and chitosan is one of the biomaterials that has proven to be an efficient adsorbent. The aim of the present work is to exploit the rearing waste of Hermetia illucens (prepupal cases), commonly known as the Black Soldier Fly (BSF), to produce chitin and its derivative chitosan by microwave-assisted process, and to study the interaction of this biopolymer with zinc and cadmium. All the samples obtained were characterized by several methods, including FTIR, XRD, TGA/DSC, 1H NMR, SEM, and viscosimetric studies. The chitosan obtained has interesting physicochemical properties with an acetylation degree (DA) equal to 2.3 %, Molecular weight (Mv) equal to 155 kDa, and a crystallinity index (ICr) around 51.26 %. Chitosan was also found to have an adsorption capacity of Cd and Zn around 141.05 mg·g-1 and 45 mg·g-1 respectively by absorption atomic spectroscopy (AAS). Results confirm the effectiveness of chitosan derived from BSF, obtained through an eco-friendly method, as a sustainable and efficient bioadsorbent for addressing heavy metal contamination

Exploring the potential use of chitosan derived from <i>Hermetia illucens</i> waste for olive oil mill wastewater treatment

International audienceIn this study, we aimed to explore a potential chitinous source, specifically the prepupal cases, which considered as a waste of Hermetia illucens. We focused on evaluating the interaction between chitosan extracted and Olive Mill Wastewater (OMW) recovered from olive oil producer in the Frouga region-Imintanout-Morocco, which presents a valuable economic income for Mediterranean countries, we aimed to replace the conventional metal-based coagulants used for pretreatment. The characterization of chitosan obtained and its interaction with OMW were studied by FTIR spectroscopy, XRD, 1H-NMR, potentiometry study, conductivity, and zeta potential measurements. The goal was to produce a healthy olive vegetation water after treatment that could potentially be reused in several fields of application such as pharmaceuticals and cosmetics. Chitosan obtained with a molecular weight of 62 KDa and an acetylation degree of 3.15% was selected as a model natural organic coagulant known by its efficiency in wastewater treatment, and the coagulation process was optimized by examining various interaction factors such as agitation and temperature. The results showed high efficiency of chitosan interaction, with maximum removal rates of iron, copper, and phosphorus reaching 86.84%, 82.14%, and 43.47%, respectively, and 77% reduction in phenolic content. The optimal performance was achieved using chitosan in interaction with olive mill wastewater with agitation factor and heating factor at 45 degrees C

Exploring the potential of chitosan/aragonite biocomposite derived from cuttlebone waste: Elaboration, physicochemical properties and in vitro bioactivity

International audienceCuttlefish bone biowaste is a potential source of a composite matrix based on chitin and aragonite. In the present work, we propose for the first time the elaboration of biocomposites based on chitosan and aragonite through the valorization of bone waste. The composition of the ventral and dorsal surfaces of bone is well studied by ICP-OES. An extraction process has been applied to the dorsal surface to extract β-chitin and chitosan with controlled physico-chemical characteristics. In parallel, aragonite isolation was carried out on the ventral side. The freeze-drying method was used to incorporate aragonite into the chitosan polymer to form CHS/ArgS biocomposites. Physicochemical characterizations were performed by FT-IR, SEM, XRD, 1H NMR, TGA/DSC, potentiometry and viscometry. The ICP-OES method was used to evaluate in vitro the bioactivity level of biocomposite in simulated human plasma (SBF), enabling analysis of the interactions between the material and SBF. The results obtained indicate that the CHS/ArgS biocomposite derived from cuttlefish bone exhibits bioactivity, and that chitosan enhances the bioactivity of aragonite. The CHS/ArgS biocomposite showed excellent ability to form an apatite layer on its surface. After three days' immersion, FTIR and SEM analyses confirmed the formation of this layer

Exploring the potential of chitosan from royal shrimp waste for elaboration of chitosan/bioglass biocomposite: Characterization and “in vitro” bioactivity

International audienceExploiting royal shrimp waste to produce value-added biocomposites offers environmental and therapeutic benefits. This study proposes biocomposites based on chitosan and bioglass, using shrimp waste as the chitosan source. Chitin extraction and chitosan preparation were characterized using various analytical techniques. The waste composition revealed 24 % chitin, convertible to chitosan, with shells containing 77.33-ppm calcium. (X-ray diffraction) XRD analysis showed crystallinity index of 54.71 % for chitin and 49.14 % for chitosan. Thermal analysis indicated degradation rates of 326 °C and 322 °C, respectively. The degree of deacetylation of chitosan was 97.08 % determined by proton nuclear magnetic resonance (1H-NMR) analysis, with an intrinsic viscosity of 498 mL.g-1 and molar mass of 101,720 g/mol, showing improved solubility in 0.3 % acetic acid. Royal chitosan (CHR) was combined with bioglass (BG) via freeze-drying to create a CHR/BG biocomposite for bone surgery applications. The bioactivity of the CHR/BG was tested in simulated body fluid (SBF), revealing a biologically active apatite layer on its surface. Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES) analysis confirmed enhanced bioactivity of the CHR/BG compared to commercial chitosan. The CHR/BG biocomposite demonstrated excellent apatite formation, validated by Scanning Electron Microscopy (SEM), highlighting its potential in bone surgery

Chitosan from Periplaneta americana L.: a sustainable solution for heavy metals removal

International audienceThe objective of this study is to explore the potential of the cockroach species, Periplaneta americana L., native to the Zagora region, in producing chitin and chitosan, contributing to water quality management and natural resource sustainability. Chitin and chitosan were extracted from the whole body of this insect and their characterization confirmed the successful extraction process. Through the Broussignac method, chitosan was obtained with a degree of acetylation (DA) of 15.3% and a molecular weight (Mv) of 75 KDa. The study focused on the interaction between this chitosan and the pollutants copper and lead, known for their detrimental health impacts. Using analysis methods such as Zeta potential and energy dispersive X-ray (EDX), it was found that chitosan has a higher affinity for copper (5 mg) than for lead (3.4 mg). These results were applied in the decontamination of real effluents polluted with heavy metals. This research aligns with Sustainable Development Goal 6 (SDG 6) by offering a promising solution for water decontamination from heavy metal pollutants, thus contributing to environmental sustainability and improved water quality in the Euro-Mediterranean region

Investigation on Akis granulifera (Coleoptera, Sahlberg, 1823) as a potential source of chitin and chitosan: Extraction, characterization and hydrogel formation

International audienceThe majority of studies have focused on the industrial exploitation of marine fisheries waste through the production of natural bioactive bioploymeres such as chitin and chitosan. However, in recent years, beetles are increasingly attracting the interest of scientists as a source of chitin and chitosan for the preparation of hydrogels for sustainable engineering development. In the present work, we focus on the study for the first time a new Moroccan species of beetle (Akis granulifera Sahlberg, 1823), for the extraction of chitin and the elaboration of chitosan. A chemical extraction process was used. Then, physicochemical characterizations by FT-IR, SEM, XRD, (1)H NMR, TGA/DSC, Potentiometry, Viscosimetry, and elemental analysis were performed. In addition, to evaluate its physicochemical quality, the elaborated chitosan is combined with alginate to form a hydrogel. This hydrogel was effectively characterized by SEM, DRX and FTIR to show the potential of chitosan from Akis granulifera in biomaterial applications

Chitosan and Its Derivatives as Potential Neuro-Protective Agents for the Treatment of Parkinson's Disease

International audienceAlthough Parkinson's disease (PD) is the second most common neurological disorder, it faces a lack of credible medications, treatments, and diagnostics. Many current conventional substances are designed as anti-Parkinson's drugs, but their poor brain transfer across the blood-brain barrier (BBB) and bioavailability are a problem. Recently, chitosan (CTS) and its derivatives from arthropod exoskeletons have attracted much attention because of their neuroprotective effects and their ability to transport therapeutic substances across the BBB. CTS and its derivatives have the ability to inhibit apoptosis, oxidative stress, and neuroinflammation. In addition to these properties, CTS nanoparticles constitute a system for the controlled delivery of therapeutic molecules across the BBB. This chapter will focus on the neuroprotective effects of CTS and its derivatives and their applications in the delivery of certain therapeutic substances

A review of chitosan polysaccharides: Neuropharmacological implications and tissue regeneration

International audienceOne of the current challenges in targeting neurological disorders is that many therapeutic molecules cannot cross the blood-brain barrier (BBB), which limits the use of natural molecules in nervous tissue regeneration. Thus, the development of new drugs to effectively treat neurological disorders would be a challenge. Natural resources are well known as a source of several therapeutic agents for the treatment of neurologic disorders. Recently, chitosan (CTS) and its derivatives from arthropod exoskeletons, have attracted much attention as a drug delivery system to transport therapeutic substances across the BBB and thanks to other neuroprotective effects including the participation to the CNS regenerations scaffolds to replicate the extracellular matrix and microenvironment of the body. This review will discuss the place of natural resource therapy in targeting neurological disorders. In particular, it will highlight recent understanding and progress in the applications of CTS as drug delivery systems and their therapeutic effects on these disorders through tissue regeneration, as well as the molecular mechanisms by which they exert these effects

Etude transversale sur les connaissances, attitudes et pratiques préventives des professionnels de la santé contre la Covid-19 au Maroc (Meknès)

La nouvelle pandémie de la Covid-19 est considérée comme l'épidémie du siècle qui a provoqué une vague de panique mondiale et a eu des effets dévastateurs sur les économies et les politiques de la plupart des pays. Les mesures préventives étaient les piliers les plus importants de la lutte contre cette pandémie. Objectifs : Cette étude vise à déterminer les connaissances, les attitudes et les pratiques préventives utilisées par les professionnels de la santé contre le coronavirus émergent. Méthodologie : Cette étude a été menée durant les mois d'Avril et Mai 2020 à l'hôpital « Sidi Saïd » à la ville de Meknès au Maroc. Un échantillonnage par commodité a été suivi pour recruter les professionnels de santé travaillant à l'hôpital. Un questionnaire autoadministré a été utilisé pour recueillir les données. Résultats : Au total, 104 professionnels de la santé ont participé à cette étude dont 70,2% étaient des femmes et 58,7% étaient des infirmiers. L'étude a révélé que la totalité des professionnels de santé ont des connaissances sur la Covid-19, et 43% d'entre eux ont confirmé avoir reçu une formation directe sur ce sujet par simulation. Les pratiques préventives les plus utilisées contre la Covid-19 étaient le port du masque (100 %), le lavage et la désinfection des mains (96 %), le port de blouse (84 %), les gants stériles (81 %) et les écrans faciaux (64 %). Conclusion : Les professionnels de la santé ont une bonne connaissance sur la Covid19 et qu’ils accordaient une grande importance au respect des mesures préventives contre la pandémie lors de leur pratique quotidienne. L'étude a conclu que malgré l'existence de toutes ces mesures, le nombre de cas de contamination enregistré parmi les professionnels de santé est important. Des études plus profondes devront être menées pour comprendre les facteurs sous-jacents limitant l’efficacité de ces mesures et la productivité des professionnels de sant