Bioactive Gelatin-based Date By-Product for Packaging Applications: Physico-Chemical and Biological Characterization

 Biodegradable films from gelatin (Gn) with various date by-product (DBP) concentrations (1, 2, 3 and 4 wt %) were prepared. Elaborated films were examined in terms of physical properties (thickness, density, water solubility, water content, degree of swelling, color), and antimicrobial properties (Escherichia coli and Staphylcoccus aureus). Adding the highest concentration of DBP (4%), resulted an increase in the WHC of film as compared with control film. Moreover, the incorporation of 1% DBP reduced the moisture level of Gn based composite films as compared with the control film. Furthermore, Film with 4% of DBP had the lowest solubility which reached 39.39%. Incorporation of DBP from 1 to 4% showed decrease of L- and a-values. The active Gn-DBP 1% showed less lightness as compared to Gn-DBP 3%. The incorporation of DBP into film-forming solutions led to increased opaqueness for all gelatin-based composite films. The calculated opacity value was inversely proportional to transparency. Moreover, the Active Gn-DBP 1% and 2% film presented effective antibacterial activity against bacteria such as Staphylococcus aureus and Escherichia coli. The results showed an enhancement in the biodegradability of Gn-DBP films in moist soil. The results reveal the benefits of date by-products incorporated into gelatin based films as a potential material for active food packaging.&nbsp

Ionic Conductivity of Strontium Fluoroapatites Co-doped with Lanthanides

Britholites derivatives of apatite’s that contain lanthanium and neodymium in the serial compounds Sr8La2−xNdx(PO4)4(SiO4)2F2 with 0 ≤ x ≤ 2 were subject of the present investigation. The solid state reaction was the route of preparing these materials. Several techniques were employed for the analysis and characterization of the synthesized powders. The chemical analysis results indicated that molar ratio Sr+La+NdP+Si was of about 1.67 value of a stoichiometric powder. The X-ray diffraction data showed single-phase apatites crystallizing in hexagonal structure with P63/m space group were successively obtained. Moreover, the substitution of lanthanium by neodymium in strontium phosphosilicated fluorapatite was total. This was confirmed by the a and c lattice parameters contraction when (x) varies coherently to the sizes of the two cations. The infrared spectroscopy and the 31P NMR (MAS) exhibited the characteristic bands of phosphosilicated fluorapatite. The pressureless sintering of the material achieved a maximum of 89% relative density. The sintered specimens indicated that the Nd content as well as the heating temperature affected the ionic conduction of the materials and the maximum was 1.73 × 10−6 S cm−1 obtained at 1052 K for x = 2

Biological therapy of strontium-substituted bioglass for soft tissue wound-healing: Responses to oxidative stress in ovariectomised rats.

The authors declare that they have no conflicts of interest concerning this article.International audienceNew synthetic biomaterials are constantly being developed for wound repair and regeneration. Bioactive glasses (BG) containing strontium have shown successful applications in tissue engineering account of their biocompatibility and the positive biological effects after implantation. This study aimed to assess whether BG-Sr was accepted by the host tissue and to characterize oxidative stress biomarker and antioxidant enzyme profiles during muscle and skin healing. Wistar rats were divided into five groups (six animals per group): the group (I) was used as negative control (T), after ovariectomy, groups II, III, IV and V were used respectively as positive control (OVX), implanted tissue with BG (OVX-BG), BG-Sr (OVX-BG-Sr) and presented empty defects (OVX-NI). Soft tissues surrounding biomaterials were used to estimate superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) and malondialdehyde (MDA) concentration. Our results show that 60 days after operation, treatment of rats with BG-Sr significantly increased MDA concentration and caused an increase of SOD, CAT and GPx activities in both skin and muscular tissues. BG-Sr revealed maturation of myotubes followed a normal appearance of muscle regenerated with high density and mature capillary vessels. High wound recovery with complete re-epithelialization and regeneration of skin was observed. The results demonstrate that the protective action against reactive oxygen species (ROS) was clearly observed in soft tissue surrounding BG-Sr. Moreover, the potential use of BG-Sr rapidly restores the wound skin and muscle structural and functional properties. The BG advantages such as ion release might make BG-Sr an effective biomaterial choice for antioxidative activity

Biocompatibility of implantable materials: an oxidative stress viewpoint

Oxidative stress occurs when the production of oxidants surpasses the antioxidant capacity in living cells. Oxidative stress is implicated in a number of pathological conditions such as cardiovascular and neurodegenerative diseases but it also has crucial roles in the regulation of cellular activities. Over the last few decades, many studies have identified significant connections between oxidative stress, inflammation and healing. In particular, increasing evidence indicates that the production of oxidants and the cellular response to oxidative stress are intricately connected to the fate of implanted biomaterials. This review article provides an overview of the major mechanisms underlying the link between oxidative stress and the biocompatibility of biomaterials. ROS, RNS and lipid peroxidation products act as chemo-attractants, signalling molecules and agents of degradation during the inflammation and healing phases. As chemo-attractants and signalling molecules, they contribute to the recruitment and activation of inflammatory and healing cells, which in turn produce more oxidants. As agents of degradation, they contribute to the maturation of the extracellular matrix at the healing site and to the degradation of the implanted material. Oxidative stress is itself influenced by the material properties, such as by their composition, their surface properties and their degradation products. Because both cells and materials produce and react with oxidants, oxidative stress may be the most direct route mediating the communication between cells and materials. Improved understanding of the oxidative stress mechanisms following biomaterial implantation may therefore help the development of new biomaterials with enhanced biocompatibility

Antioxidative/oxidative status of muscular tissue surrounding strontium-substituted bioactive glass implanted in bone of ovariectomised rats

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Repair of bone defect using bioglass-chitosan as a pharmaceutical drug: An experimental study in an ovariectomised rat model

International audienceBone loss associated with skeletal trauma or metabolic diseases often require bone grafting. The present study aimed to evaluate the performance of bioactive glass-chitosan composite (BG-CH) produced by a freeze-drying process. BG containing 17% wt% CH was implanted in the femoral condyl of an ovariectomised rat. The resected bone was prepared for analysis using several physico-chemical techniques such as fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy-dispersive X-ray (EDX). After 2 weeks, the implanted sample gave a spectrum in which two pronounced absorption bands with the maxima at 932 and 1036 cm(-1) arising from (Si-O-Si) groups disappeared 15 days after surgery. These bands were replaced 30 days after implantation by 601 and 564 cm(-1) (P- O) arisen form bone apatite bands. After 4 weeks, peaks at 31.6 and 25.8 degrees (2 theta) were registered thus inducing a degradation of BG-CH which occurred simultaneously with the implant replacement by the bone cells. Our data showed that the incorporation of 17% wt% CH with BG matrix promoted a highly significant bioactivity and generated an osteoinductive property. These effects might make BG-CH an effective biomaterials choice for the biomedical field

Antioxidative/oxidative effects of strontium-doped bioactive glass as bone graft. In vivo assays in ovariectomised rats

International audienceRecently, oxidative stress has been identified as a pivotal pathological factor inducing bone osteoporosis. This phenomenon is responsible for low bone density. It alters bone quality and generates bone fractures. Strontium is found to induce osteoblast activity by stimulating bone formation and reducing bone resorption by restraining osteoclasts. Bioglass (BG) has been used to repair bone defects, and, in combination with strontium (BG-Sr), offers an opportunity to treat this disease. This study investigated the potential role of BG-Sr in improving antioxidant activity and regenerative bone capacity, The effects of both BG-Sr and BG were tested on osteoblast SaOS2 and endothelial EAhy926 cell proliferation in vitro. In vivo, BG-Sr and BG were implanted in the femoral condyles of Wistar rats and compared to that of control groups. Cell proliferation increased significantly by 120% at SaOS2 and 127% at EAhy926. Superoxide Dismutase (SOD), Catalase (CAT) and Glutathione Peroxidase (GPx) were significantly enhanced in BG-Sr treated rats compared to other groups. Moreover, a significant decrease of thiobarbituric acid-reactive substances (TBARs) was observed. The Ca/P ratio increase improved progressive bone mineralization. According to these results, BG-Sr ameliorated cell proliferation and developed an antioxidative defense against ROS. The histological findings highlight the BG-Sr implications in the osteoporosis treatment confirmed by bone construction. The development of BG-Sr as a therapeutic biomaterial protecting against oxidative stress might make an effective choice for application in tissue engineering

Cytocompatibility, gene-expression profiling, apoptotic, mechanical and 29Si, 31P solid-state nuclear magnetic resonance studies following treatment with a bioglass-chitosan composite

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Biologic response to carbonated hydroxyapatite associated with orthopedic device: experimental study in a rabbit model.

International audienceBACKGROUND: Carbonated hydroxyapatite (CHA) and related calcium phosphates have been studied for many years as implant materials due to their similarity with the mineral phase of bone. The main limitation of CHA ceramics as well as other bioactive materials is that they have poor mechanical proprieties. It is thought that the mechanical device can cause an increase in metabolic activity and bone healing. In this study we investigated the reactivity and tissue behaviour of implanted CHA biomaterial reinforced by mini external fixator. METHODS: The evaluation of biomaterial biocompatibility and osteogenesis was performed on a rabbit model over a period of 6 weeks by radiological, histological and scanning electron microscopy (SEM) coupled with energy dispersive X-ray SEM-energy-dispersive X-ray (EDX) analysis. RESULTS: While rabbits treated with CHA exhibited more bone formation, and fibrous tissue was observed when empty bone defects were observed. EDX analysis detected little calcium and phosphorus on the surface of the bone that was not implanted, while high content of calcium (62.7%) and phosphorus (38%) was found on the interface bone cement. CONCLUSIONS: Bone repairing showed that the mini external fixator stimulated the ossification which was pushed when grafted by CHA. This effect may play an important role in the prevention of implant loosening