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

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

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.

Shedding light on surface exposition of poly(ethylene glycol) and folate targeting units on nanoparticles of poly(ε-caprolactone) diblock copolymers: beyond a paradigm

Polymeric nanoparticles (NPs) of poly(\u3b5-caprolactone) (PCL) covered with a hydrophilic poly(ethylene glycol) (PEG) shell are usually prepared from diblock PEG-PCL copolymers through different techniques. Furthermore PEG, NPs can be decorated with targeting ligands to accumulate in specific cell lines. However, the density and conformation of PEG on the surface and its impact on the exposition of small targeting ligands has been poorly considered so far although this has a huge impact on biological behaviour. Here, we focus on PEG-PCL NPs and their folate-targeted version to encourage accumulation in cancer cells overexpressing folate receptor \u3b1. NPs were prepared with mixtures of PEG-PCL with different PEG length (short 1.0kDa, long 2.0kDa,) and a folate-functionalized PEG-PCL (PEG 1.5kDa) by the widely employed solvent displacement method. In depth characterization of NPs surface by 1H NMR, fluorescence and photon correlation spectroscopy evidenced a PEGylation extent below 7% with PEG in a mushroom conformation and the presence of folate more exposed to water pool in the case of copolymer with short PEG. NPs with short PEG adsorbed HSA forming a soft corona without aggregating. Although limited, PEGylation overall reduced NPs uptake in human macrophages. Uptake of NPs exposing folate prepared with short PEG was higher in KB cells (FR+) than in A549 (FR-), occurred via FR-receptor and involved lipid rafts-dependent endocytosis. In conclusion, the present results demonstrate that PEG length critically affects protein interaction and folate exposition with a logical impact on receptor-mediated cell uptake. Our study highlights that the too simplistic view suggesting that PEG-PCL gives PEG-coated NPs needs to be re-examined in the light of actual surface properties, which should always be considered case-by-case

Separation and recovery of a hemicellulose-derived sugar produced from the hydrolysis of biomass by an acidic ionic liquid

ABSTRACT: Biomass processing with ionic liquids (ILs) has been one of the most topical research areas in recent years. However, separation and recovery of biomass products and ILs are currently a challenge. Recovery of produced monosaccharides from an IL postreaction solution and the possibility to reuse the IL are strongly required to guarantee the sustainability of biomass processing. The present study demonstrates a novel approach that aims at separating a biomass hemicellulose-derived product, namely, xylose, and 1-ethyl-3-methylimidazolium hydrogensulfate ([emim][HSO4]). High polarity of a postreaction system composed of xylose, IL, and water is one of the major hindrances in the separation performance. A proposed solution is fine-tuning of the system polarity by the addition of moderately polar acetonitrile. To scrutinize the potential of xylose and IL separation, phase equilibria of a system constituted by [emim][HSO4], water, and acetonitrile were studied. Additionally, preparative chromatography experiments with alumina as a stationary phase were performed to determine the conditions required for efficient separation of the sugar and the IL by selective adsorption of xylose on alumina in detriment of IL. The amount and treatment of the stationary phase, eluent polarity, and amount of loaded sample were also scrutinized in this study. Treatment of alumina was considered as a necessary step to achieve recovery yields of 90.8 and 98.1 wt% for the IL and xylose, respectively, as separate fractions.info:eu-repo/semantics/publishedVersio

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

Conservative management for postprostatectomy urinary incontinence

BACKGROUND: Urinary incontinence is common after radical prostatectomy and can also occur in some circumstances after transurethral resection of the prostate (TURP). Conservative management includes pelvic floor muscle training with or without biofeedback, electrical stimulation, extra-corporeal magnetic innervation (ExMI), compression devices (penile clamps), lifestyle changes, or a combination of methods.   OBJECTIVES: To determine the effectiveness of conservative management for urinary incontinence up to 12 months after transurethral, suprapubic, laparoscopic, radical retropubic or perineal prostatectomy, including any single conservative therapy or any combination of conservative therapies.  SEARCH METHODS: We searched the Cochrane Incontinence Group Specialised Register (5 February 2014), CENTRAL (2014, Issue 1), EMBASE (January 2010 to Week 3 2014), CINAHL (January 1982 to 18 January 2014), ClinicalTrials.gov and World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP) (both searched 29 January 2014), and the reference lists of relevant articles.  SELECTION CRITERIA: Randomised or quasi-randomised controlled trials evaluating conservative interventions for urinary continence in men after prostatectomy.  DATA COLLECTION AND ANALYSIS: Two or more review authors assessed the methodological quality of the trials and abstracted data. We tried to contact several authors of included studies to obtain extra information.  MAIN RESULTS: Fifty trials met the inclusion criteria, 45 in men after radical prostatectomy, four trials after TURP and one trial after either operation. The trials included 4717 men of whom 2736 had an active conservative intervention. There was considerable variation in the interventions, populations and outcome measures. Data were not available for many of the pre-stated outcomes. Men's symptoms improved over time irrespective of management.There was no evidence from eight trials that pelvic floor muscle training with or without biofeedback was better than control for men who had urinary incontinence up to 12 months after radical prostatectomy; the quality of the evidence was judged to be moderate (for example 57% with urinary incontinence in the intervention group versus 62% in the control group, risk ratio (RR) for incontinence after 12 months 0.85, 95% confidence interval (CI) 0.60 to 1.22). One large multi-centre trial of one-to-one therapy showed no difference in any urinary or quality of life outcome measures and had narrow CIs. It seems unlikely that men benefit from one-to-one PFMT therapy after TURP. Individual small trials provided data to suggest that electrical stimulation, external magnetic innervation, or combinations of treatments might be beneficial but the evidence was limited. Amongst trials of conservative treatment for all men after radical prostatectomy, aimed at both treatment and prevention, there was moderate evidence of an overall benefit from pelvic floor muscle training versus control management in terms of reduction of urinary incontinence (for example 10% with urinary incontinence after one year in the intervention groups versus 32% in the control groups, RR for urinary incontinence 0.32, 95% CI 0.20 to 0.51). However, this finding was not supported by other data from pad tests. The findings should be treated with caution because the risk of bias assessment showed methodological limitations. Men in one trial were more satisfied with one type of external compression device, which had the lowest urine loss, compared to two others or no treatment. The effect of other conservative interventions such as lifestyle changes remained undetermined as no trials involving these interventions were identified.  AUTHORS' CONCLUSIONS: The value of the various approaches to conservative management of postprostatectomy incontinence after radical prostatectomy remains uncertain. The evidence is conflicting and therefore rigorous, adequately powered randomised controlled trials (RCTs) which abide by the principles and recommendations of the CONSORT statement are still needed to obtain a definitive answer. The trials should be robustly designed to answer specific well constructed research questions and include outcomes which are important from the patient's perspective in decision making and are also relevant to the healthcare professionals. Long-term incontinence may be managed by an external penile clamp, but there are safety problems