Lactose-crosslinked fish gelatin-based porous scaffolds embedded with tetrahydrocurcumin for cartilage regeneration

Tetrahydrocurcumin (THC) is one of the major colourless metabolites of curcumin and shows even greater pharmacological and physiological benefits. The aim of this work was the manufacturing of porous scaffolds as a carrier of THC under physiological conditions. Fish-derived gelatin scaffolds were prepared by freeze-drying by two solutions concentrations (2.5% and 4% w/v), cross-linked via addition of lactose and heat-treated at 105 °C. This cross-linking reaction resulted in more water resistant scaffolds with a water uptake capacity higher than 800%. Along with the cross-linking reaction, the gelatin concentration affected the scaffold morphology, as observed by scanning electron microscopy images, by obtaining a reduced porosity but larger pores sizes when the initial gelatin concentration was increased. These morphological changes led to a scaffold's strength enhancement from 0.92 ± 0.22 MPa to 2.04 ± 0.18 MPa when gelatin concentration was increased. THC release slowed down when gelatin concentration increased from 2.5 to 4% w/v, showing a controlled profile within 96 h. Preliminary in vitro test with chondrocytes on scaffolds with 4% w/v gelatin offered higher metabolic activities and cell survival up to 14 days of incubation. Finally the addition of THC did not influence significantly the cytocompatibility and potential antibacterial properties were demonstrated successfully against Staphylococcus aureus

A Review on the Mechanical Modeling of Composite Manufacturing Processes

© 2016, The Author(s). The increased usage of fiber reinforced polymer composites in load bearing applications requires a detailed understanding of the process induced residual stresses and their effect on the shape distortions. This is utmost necessary in order to have more reliable composite manufacturing since the residual stresses alter the internal stress level of the composite part during the service life and the residual shape distortions may lead to not meeting the desired geometrical tolerances. The occurrence of residual stresses during the manufacturing process inherently contains diverse interactions between the involved physical phenomena mainly related to material flow, heat transfer and polymerization or crystallization. Development of numerical process models is required for virtual design and optimization of the composite manufacturing process which avoids the expensive trial-and-error based approaches. The process models as well as applications focusing on the prediction of residual stresses and shape distortions taking place in composite manufacturing are discussed in this study. The applications on both thermoset and thermoplastic based composites are reviewed in detail

International lower limb collaborative (INTELLECT) study: a multicentre, international retrospective audit of lower extremity open fractures

Trauma remains a major cause of mortality and disability across the world1, with a higher burden in developing nations2. Open lower extremity injuries are devastating events from a physical3, mental health4, and socioeconomic5 standpoint. The potential sequelae, including risk of chronic infection and amputation, can lead to delayed recovery and major disability6. This international study aimed to describe global disparities, timely intervention, guideline-directed care, and economic aspects of open lower limb injuries

Vampires in the village Žrnovo on the island of Korčula: following an archival document from the 18th century

Središnja tema rada usmjerena je na raščlambu spisa pohranjenog u Državnom arhivu u Mlecima (fond: Capi del Consiglio de’ Dieci: Lettere di Rettori e di altre cariche) koji se odnosi na događaj iz 1748. godine u korčulanskom selu Žrnovo, kada su mještani – vjerujući da su se pojavili vampiri – oskvrnuli nekoliko mjesnih grobova. U radu se podrobno iznose osnovni podaci iz spisa te rečeni događaj analizira u širem društvenom kontekstu i prate se lokalna vjerovanja.The main interest of this essay is the analysis of the document from the State Archive in Venice (file: Capi del Consiglio de’ Dieci: Lettere di Rettori e di altre cariche) which is connected with the episode from 1748 when the inhabitants of the village Žrnove on the island of Korčula in Croatia opened tombs on the local cemetery in the fear of the vampires treating. This essay try to show some social circumstances connected with this event as well as a local vernacular tradition concerning superstitions

Properties and characteristics of salmon frame protein isolate films influenced by glycerol and squalene

Characteristics of edible/biodegradable film based on salmon frame protein isolate (SFPI), a processing by-product, containing glycerol at two different concentrations (50 and 65% by weight of protein) with and without 30% squalene (by weight of protein) were investigated. Without squalene, the SFPI film generally had higher hydrophilicity when higher concentration of glycerol was used as indicated by higher (p < 0.05) water-vapour permeability (WVP). The addition of squalene augmented yellowness and hydrophobicity of SFPI film as indicated by higher b* colour coordinate and lower WVP (p < 0.05), respectively, in comparison to those without squalene. The squalene also promoted the interactions in SFPI film matrix as revealed by Fourier-transform infrared spectra. These interactions were related to a superior mechanical properties, high barrier properties, and increased thermal resistance of the resulting SFPI film. Therefore, the addition of 30 squalene along with 50% glycerol as plasticiser improved physicochemical, mechanical, barrier, and thermal properties of SFPI film, which could be used as an alternative film for edible/biodegradable food packaging

Physical and antioxidant properties of starch/gelatin films incorporated with Garcinia atroviridis leaves

The potential application of Garcinia atroviridis leaves (GAL) extract as an active compound in tapioca starch/gelatin films for natural-based food packaging was studied in this work. Films with different concentrations of GAL extract (1, 3 and 5 %) were prepared by solution casting and the obtained films were homogenous, as observed by scanning electron microscopy (SEM). Regarding mechanical properties, tensile strength (TS) and elongation at break (EAB) increased with GAL concentration, leading to stronger and more flexible films. Furthermore, a higher level of GAL reduced water solubility. Additionally, DPPH radical scavenging assay showed that the antioxidant properties of the films were improved with the addition of GAL extract. Therefore, GAL extract incorporated into film-forming formulations showed potential as antioxidant additive. However, future research is essential to assess the shelf-life extension for various types of food products

Electrospinning of fish gelatin solution containing citric acid: An environmentally friendly approach to prepare crosslinked gelatin fibers

The majority of the crosslinking approaches employed to confer water resistance properties to electrospun gelatin mats are based on the use of potential cytotoxic agents, turning out to be not suitable for biomedical applications. Environmentally friendly chemical strategies based on the use of non-toxic agents are, therefore, strongly demanded. In the present work, the possibility to produce crosslinked electrospun fish gelatin mats by electrospinning an aqueous solution, containing citric acid as a crosslinking agent, is reported. The effect of pH on solution rheological properties, as well as on the electrospun mat morphology, chemistry, and crosslinking degree, is assessed. The increase of solution pH from 1.8 to 3.7 allows for obtaining fibers that maintain the fibrous morphology also in the mat. Subsequent thermal treatment of the electrospun mat (80 \ub0C for 30 min) turns out to increase the crosslinking degree and morphological stability of the mat

Kinetic and thermodynamic studies of the formation of a polyurethane based on 1,6-hexamethylene diisocyanate and poly(carbonate-co-ester)diol

This paper presents the kinetic and thermodynamic characterization of a non-catalyzed reaction between poly(hexamethylene carbonate-co-caprolactone)diol (PHMC-co-PCL) and aliphatic hexamethylene diisocyanate (HDI) with a stochiometric functional concentration, using both isothermal and dynamic differential scanning calorimetry, DSC, as well as Fourier transform infrared spectroscopy, FT-IR. DSC data were fitted using a Kamal autocatalytic equation. Model-free-isoconversional methods were also applied to analyse the conversion dependence of the global activation energy. This relation was used to predict the reaction conversion versus time pattern at different temperatures and to compare it with that of the model approach. Kinetic modelling and model-free analysis successfully described the conversion versus time curves. The reaction can be divided in two different paths: the forward path and the autocatalyzed one. Results corroborated that autocatalysis is promoted by the urethane group. Activation energies for both reaction paths have been found to be higher than those presented in the literature for aromatic diisocyanate systems, which explains the lower reaction rate of the presented system. © 2007 Elsevier B.V. All rights reserved.Fil: Fernández d’Arlas, Borja. Euskal Herriko Unibertsitatea; EspañaFil: Rueda, L.. Euskal Herriko Unibertsitatea; EspañaFil: Stefani, Pablo Marcelo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; ArgentinaFil: de la Caba, K.. Euskal Herriko Unibertsitatea; EspañaFil: Mondragon, I.. Euskal Herriko Unibertsitatea; EspañaFil: Eceiza, A.. Euskal Herriko Unibertsitatea; Españ