36 research outputs found
Marine Polysaccharides Volume 1
The field of marine polysaccharides is constantly evolving, due to progress in the discovery and production of new marine polysaccharides. Seaweed remains the most abundant source of polysaccharides, but recent advances in biotechnology have allowed the production of large quantities of polysaccharides from a variety of micro-algae, by controlling growth conditions and tailoring the production of bioactive compounds in a bioreactor. Of particular interest are polysaccharides produced by micro-organisms from extreme marine environments, due to their recognized different biochemistry. Extracellular polysaccharides (EPSs) with unique properties produced by a number of micro-algae are known. The first volume is a collection of papers concerning the identification and characterization of novel marine polysaccharides. It is divided into three chapters; the first two are dedicated to polysaccharides from different marine sources (algae, micro-algae, animals), while the third one gathers information on the isolation, characterization and bioactivity of new EPSs
Alginate/human elastin-like polypeptide composite films with antioxidant properties for potential wound healing application
In this contribution we describe the preparation and characterization of a series of cross-linked films based on the combination of an elastin-derived biomimetic polypeptide (Human elastin-like polypeptide (HELP)) with alginate (ALG) to obtain a composite with enhanced properties. ALG/HELP composite films loaded with the hydrophobic natural antioxidant curcumin were prepared by solvent casting method followed by the cross-linking with calcium chloride. The compatibility between the two components as well as the final properties was evaluated. The micro-morphological study of films showed a homogeneous structure, but the film tensile strength decrease with HELP content and elongation at break was adversely affected by biopolymer addition. Spectroscopic and thermal analyses confirmed an interaction between ALG and HELP which also causes a modification in swelling kinetics and faster degradation. Moreover, the study of curcumin release showed a controlled delivery up to 10\u202fdays with a faster release rate in the presence of HELP. Human Dermal Fibroblasts (hDF) were used to test the in vitro cytocompatibility. The antioxidant activity correlated to the increase of HELP content suggested the applicability of these composites to develop smart biomaterials. Overall, these features indicated how this composite material has considerable potential as customizable platforms for various biomedical applications
Water buffalo mozzarella cheese stored in polysaccharide-based gels: correlation between prolongation of the shelf-life and physicochemical parameters.
An innovative packaging system has been developed, based on natural gels, that has shown the peculiar characteristic to strongly increase the shelf life of water buffalo Mozzarella cheese. To explain the mechanism of action of the gel, measurements of Ca and Na in the cheese and in the storage liquid were carried out, together with pH determination. A correlation has been found between the constant level of Ca and pH in the cheese and the prolongation of nutritional characteristics; in fact, both parameters diminish significantly in the absence of gel. At the same time, the weight of the cheese in gel remained constant for as long as 30 d. Confocal laser microscopy gave direct evidence of the persistent physical structure of proteins and lipids of Mozzarella when stored in gel
OPTIMASI KONDISI LARUTAN DAN PARAMETER PROSES PEMINTALAN ELEKTRIK PADA SINTESIS SERAT NANO KITOSAN-PEO
Serat nano kitosan telah berhasil dibuat dengan penambahan polietilen oksida (PEO) sebagai polimer sekunder pada kondisi larutan dan parameter proses pemintalan elektrik yang optimum. Pada penelitian ini, larutan polimer kitosan/PEO pada berbagai konsentrasi (3,2, 3,6, dan 4 wt%) dan rasio (3:2 dan 1:1) dipintal secara elektrik (electrospinning) untuk memperoleh serat dengan morfologi paling baik. Selain kondisi larutan, parameter proses pintal elektrik yang penting seperti tegangan, laju alir umpan, dan jarak antara jarum dengan kolektor juga disesuaikan untuk mendapatkan proses dengan kondisi jet polimer yang stabil. Serat nano yang terbaik yakni tanpa butiran polimer (polymer microspheres) dan minim jumlah manik-manik (beads) berhasil diperoleh pada konsentrasi kitosan/PEO 4 wt% dan rasio 3:2. Parameter proses yang digunakan untuk mendapatkan serat ini yaitu tegangan 30 kV, laju alir umpan 0,3 ml/jam, dan jarak antara jarum dan kolektor 30 cm. Karakterisasi morfologi serat dari setiap eksperimen dilakukan dengan menggunakan mikroskop Phenom. Selanjutnya, serat nano terbaik yang diperoleh dikarakterisasi dengan menggunakan SEM dan diameter rata-rata serat diukur dengan aplikasi ImageJ. Hasil menunjukkan bahwa serat nano yang dihasilkan pada kondisi optimum memiliki diameter rata-rata 68 nm dan distribusi ukuran diameter serat tersebar cukup lebar mulai dari 30-150 nm.
Functionalized PCL/HA nanocomposites as microporous membranes for bone regeneration
In the present work, microporous membranes based on poly(ε-caprolactone) (PCL) and PCL functionalized with amine (PCL-DMAEA) or anhydride groups (PCL-MAGMA) were realized by solvent-non solvent phase inversion and proposed for use in Guided Tissue Regeneration (GTR). Nanowhiskers of hydroxyapatite (HA) were also incorporated in the polymer matrix to realize nanocomposite membranes. Scanning Electron Microscopy (SEM) showed improved interfacial adhesion with HA for functionalized polymers, and highlighted substantial differences in the porosity. A relationship between the developed porous structure of the membrane and the chemical nature of grafted groups was proposed. Compared to virgin PCL, hydrophilicity increases for functionalized PCL, while the addition of HA influences significantly the hydrophilic characteristics only in the case of virgin polymer. A significant increase of in vitro degradation rate was found for PCL-MAGMA based membranes, and at lower extent of PCL-DMAEA membranes. The novel materials were investigated regarding their potential as support for cell growth in bone repair using multipotent mesenchymal stromal cells (MSC) as a model. MSC plated onto the various membranes were analyzed in terms of adhesion, proliferation and osteogenic capacity that resulted to be related to chemical as well as porous structure. In particular, PCL-DMAEA and the relative nanocomposite membranes are the most promising in terms of cell-biomaterial interactions
Correction: Biodegradable nanoparticles bearing amine groups as a strategy to alter surface features, biological identity and accumulation in a lung metastasis model
Correction for 'Biodegradable nanoparticles bearing amine groups as a strategy to alter surface features, biological identity and accumulation in a lung metastasis model' by Diletta Esposito et al., J. Mater. Chem. B, 2018, 6, 5922–5930
Marine Polysaccharides in Pharmaceutical Applications: An Overview
The enormous variety of polysaccharides that can be extracted from marine plants and animal organisms or produced by marine bacteria means that the field of marine polysaccharides is constantly evolving. Recent advances in biological techniques allow high levels of polysaccharides of interest to be produced in vitro. Biotechnology is a powerful tool to obtain polysaccharides from a variety of micro-organisms, by controlling the growth conditions in a bioreactor while tailoring the production of biologically active compounds. Following an overview of the current knowledge on marine polysaccharides, with special attention to potential pharmaceutical applications and to more recent progress on the discovering of new polysaccharides with biological appealing characteristics, this review will focus on possible strategies for chemical or physical modification aimed to tailor the final properties of interest
Marine Polysaccharides Volume 2
The field of marine polysaccharides is constantly evolving, due to progress in the discovery and production of new marine polysaccharides. Seaweed remains the most abundant source of polysaccharides, but recent advances in biotechnology have allowed the production of large quantities of polysaccharides from a variety of micro-algae, by controlling growth conditions and tailoring the production of bioactive compounds in a bioreactor. Of particular interest are polysaccharides produced by micro-organisms from extreme marine environments, due to their recognized different biochemistry. Extracellular polysaccharides (EPSs) with unique properties produced by a number of micro-algae are known. The first volume is a collection of papers concerning the identification and characterization of novel marine polysaccharides. It is divided into three chapters; the first two are dedicated to polysaccharides from different marine sources (algae, micro-algae, animals), while the third one gathers information on the isolation, characterization and bioactivity of new EPSs