Needle-punched three-dimensional nonwoven wound dressings with density gradient from biocompatible calcium alginate fiber

2018 ◽  
Vol 89 (14) ◽  
pp. 2776-2788 ◽  
Author(s):  
Yingjun Gao ◽  
Xiangyu Jin
Keyword(s):  
Density Gradient ◽  
Calcium Alginate ◽  
Three Dimensional ◽  
Wound Dressings ◽  
Alginate Fiber

scholarly journals Xanthan Gum–Konjac Glucomannan Blend Hydrogel for Wound Healing

Polymers ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 99 ◽  
Author(s):  
Andreia Alves ◽  
Sónia P. Miguel ◽  
André R.T.S. Araujo ◽  
María José de Jesús Valle ◽  
Amparo Sánchez Navarro ◽  
...  
Keyword(s):  
Xanthan Gum ◽  
Biomedical Application ◽  
Three Dimensional ◽  
High Water ◽  
Biological Properties ◽  
Konjac Glucomannan ◽  
Wound Dressings ◽  
Dimensional Structure ◽  
Future Application ◽  
High Water Content

Hydrogels are considered to be the most ideal materials for the production of wound dressings since they display a three-dimensional structure that mimics the native extracellular matrix of skin as well as a high-water content, which confers a moist environment at the wound site. Until now, different polymers have been used, alone or blended, for the production of hydrogels aimed for this biomedical application. From the best of our knowledge, the application of a xanthan gum–konjac glucomannan blend has not been used for the production of wound dressings. Herein, a thermo-reversible hydrogel composed of xanthan gum–konjac glucomannan (at different concentrations (1% and 2% w/v) and ratios (50/50 and 60/40)) was produced and characterized. The obtained data emphasize the excellent physicochemical and biological properties of the produced hydrogels, which are suitable for their future application as wound dressings.

scholarly journals Nanocellulose-Based Inks—Effect of Alginate Content on the Water Absorption of 3D Printed Constructs

2019 ◽  
Vol 6 (3) ◽  
pp. 65 ◽  
Author(s):  
Eduardo Espinosa ◽  
Daniel Filgueira ◽  
Alejandro Rodríguez ◽  
Gary Chinga-Carrasco
Keyword(s):  
Water Absorption ◽  
Moisture Absorption ◽  
Cellulose Nanofibrils ◽  
Three Dimensional ◽  
Wound Dressings ◽  
Cross Linking ◽  
Porous Structures ◽  
Freeze Dried ◽  
3D Printed ◽  
The Cross

2,2,6,6-tetramethylpyperidine-1-oxyl (TEMPO) oxidized cellulose nanofibrils (CNF) were used as ink for three-dimensional (3D) printing of porous structures with potential as wound dressings. Alginate (10, 20, 30 and 40 wt%) was incorporated into the formulation to facilitate the ionic cross-linking with calcium chloride (CaCl2). The effect of two different concentrations of CaCl2 (50 and 100 mM) was studied. The 3D printed hydrogels were freeze-dried to produce aerogels which were tested for water absorption. Scanning Electronic Microscopy (SEM) pictures demonstrated that the higher the concentration of the cross-linker the higher the definition of the printed tracks. CNF-based aerogels showed a remarkable water absorption capability. Although the incorporation of alginate and the cross-linking with CaCl2 led to shrinkage of the 3D printed constructs, the approach yielded suitable porous structures for water and moisture absorption. It is concluded that the 3D printed biocomposite structures developed in this study have characteristics that are promising for wound dressings devices.

scholarly journals DYNAMICS OF A LONGITUDINALLY STRATIFIED ESTUARY

1976 ◽  
Vol 1 (15) ◽  
pp. 177 ◽  
Author(s):  
Jorg Imberger
Keyword(s):  
Density Gradient ◽  
Fresh Water ◽  
Salinity Gradient ◽  
Vertical Mixing ◽  
Three Dimensional ◽  
First Order ◽  
Vertical Density ◽  
Stratified Estuary ◽  
Set Up ◽  
Australian Estuary

Introduction. A partially stratified estuary is defined as one which possesses a quite definite longitudinal salinity gradient from the mouth to the head of the estuary, but only a very weak vertical or transverse salinity structure. For an estuary to exhibit such characteristics it must possess a source of fresh water near the head of the estuary, sufficient vertical mixing to overcome the potential energy associated with such a fresh water inflow and be very much longer than its width to reduce transverse variations. If the estuary is very shallow (a few meters) then wind generated turbulence is often sufficient to eliminate most or all the vertical structure. Deeper, or very sheltered, estuaries require additional strong tidal shears to break up the vertical density gradients. However, in both cases the mixing is usually not sufficient to completely homogenize the estuary longitudinally and it is found that these estuaries display a near linear salinity gradient along the principle axis of the estuary throughout most of the spring and summer months. Such a density gradient drives a gravitational circulation within the estuary which leads to a net transport of salt from the sea mouth to the head of the estuary. Two dimensional theories (see for instance Rat tray and Mitsuda (1974)) have been established, but In general these greatly underestimate the longitudinal transport found in such estuaries and three dimensional circulation effects must be considered. Fischer (1972) was the first to recognise this fact and he carried out a first order analysis which pointed to a greatly increased longitudinal dispersion. However, Fischer (1972) carried out his analysis only to first order, not explaining how the transverse pressure field, set up by the first order velocity field convecting the longitudinal density gradient, is balanced. It is the purpose of this paper to give a rigorous foundation to Fischer's (1972) hypothesis that it is the transverse variations in velocity which yield the greatest contribution to any longitudinal transport of the density or any passive pollutant. Furthermore, the presented theory is applied to a local Western Australian estuary which is ideally suited for such a comparison complying strictly to the assumptions of the theory.

scholarly journals Calcitonin Gene-Related Peptide-Induced Calcium Alginate Gel Combined with Adipose-Derived Stem Cells Differentiating to Osteoblasts

2015 ◽  
Vol 73 (3) ◽  
pp. 609-617 ◽  
Author(s):  
Chang-zhi Huang ◽  
Xiao-ning Yang ◽  
Da-cheng Liu ◽  
Yi-gong Sun ◽  
Xing-ming Dai
Keyword(s):  
Calcium Alginate ◽  
Calcium Concentration ◽  
Three Dimensional ◽  
Osteoblastic Differentiation ◽  
Control Group ◽  
Alginate Gel ◽  
Calcitonin Gene ◽  
Calcium Alginate Gel ◽  
Osteogenic Induction ◽  
Experimental Group

Abstract Calcitonin gene-related peptide (CGRP) has been confirmed with induction osteoblastic differentiation, but if it can make the three-dimensional culture of adipose-derived stem cells (ADSCs) to the osteoblastic differentiation, thus constructing tissue-engineered bone rare reports. To investigate the feasibility of exogenous CGRP-induced calcium alginate gel combined with ADSCs from rabbits in three-dimensional condition to construct tissue-engineered bone. ADSCs were obtained by collagenase I digestion of the subcutaneous adipose tissue of inguinal region of New Zealand rabbits. At the third passage, cells were mixed with sodium alginate to prepare calcium alginate gel, and the cells were assigned into two-group cultivates in 24 orifice plates. ADSCs in the control group were treated with DMEM/F-12 medium supplemented with 10−2 mol/L β-glycerophosphate sodium, 10−7mol/L dexamethasone, 50 mg/L ascorbic acid, 0.1 % volume fraction of fetal bovine serum. ADSCs in the experimental group were incubated with the same medium as above, and in addition 1.5 µg/L CGRP was added. The cells proliferation and the mRNA expressions of collagen I and osteocalcin were detected by MTT and RT-PCR assays, respectively and alkaline phosphatase(ALP)and calcium concentration at different induction time were detected. The cell proliferation curves were S shaped. The OD values of experimental group were higher than those of control group at 1, 3, 5, 7, 14, and 21 days after osteogenic induction (P < 0.05). ALP and alizarin red stains of ADSCs were all positive, but golden round nodes became bigger and more in the experimental group compared with the control group after 2 weeks. At 7 and 14 days, collagen I and osteocalcin mRNA expression were greater in the experimental group than the control group. ALP and calcium concentration of experimental group were higher than that of control group at 1, 2, 3, 4 weeks after osteogenic induction (P < 0.05). Thus, these results show that the CGRP-induced ADSCs combined with calcium alginate gel to osteoblasts differentiation.

scholarly journals Three-dimensional multilayered fibrous constructs for wound healing applications

2016 ◽  
Vol 4 (2) ◽  
pp. 319-330 ◽  
Author(s):  
Tiago C. Reis ◽  
Steven Castleberry ◽  
Ana M. B. Rego ◽  
Ana Aguiar-Ricardo ◽  
Paula T. Hammond
Keyword(s):  
Wound Healing ◽  
Physicochemical Properties ◽  
Three Dimensional ◽  
Wound Dressings ◽  
Self Organization ◽  
Electrospun Fibers

Electrical driven self-organization of electrospun fibers is used to create topographically bioinspired three-dimensional multilayered constructs, with tunable morphological and physicochemical properties for ideal wound dressings.

scholarly journals МОДЕЛЮВАННЯ ПРОЦЕСІВ ВОЛОГОПЕРЕНОСУ В БАГАТОШАРОВИХ АПЛІКАЦІЙНИХ МАТЕРІАЛАХ МЕДИЧНОГО ПРИЗНАЧЕННЯ

2020 ◽  
Vol 144 (2) ◽  
pp. 54-61
Author(s):  
Г. В. Шуцька ◽  
Н. П. Супрун ◽  
Г. М. Пожилов-Несміян
Keyword(s):  
Moisture Transfer ◽  
Three Dimensional ◽  
Medical Application ◽  
Geometric Parameters ◽  
Raw Material ◽  
Wound Dressings ◽  
The Real ◽  
Three Dimensional Modeling ◽  
Dimensional Modeling ◽  
Computer Environment

To carry out modeling of moisture transfer processes in multilayer medical application materials for forecasting of targeted transport of drugs of a certain effective concentration into the lesion center, based on the geometric parameters of the wounds. Using digital image processing techniques in a computer environment have developed methods for designing three-dimensional fluid propagation effects in multilayer medical wound dressings. Modern wound dressings have been found to be multilayer multidimensional compositions with complex fluid kinetics. Additionally, the wounds on the human body itself have a complex space geometric shape. This requires taking into account the volumetric effects when analyzing and forecasting the processes of wetting and fluid flow in such systems. An algorithm for ordering the boundary of a wound by digital photography with the subsequent processing of a wound image in a computer environment is proposed. To evaluate the moisture transport properties for the controlled release of medicinal substances at the desired concentration in different layers of wound dressings, an experiment was made with wetting from two and three sources, followed by three-dimensional modeling. It has been experimentally found that the parameters of the layered distribution of liquid moisture in multilayer dressings vary significantly.. The results of the simulation are suitable for making prompt decisions about the type, the required geometric parameters of medical materials and wound dressings. The proposed method of establishing the real geometry of the wound, together with three-dimensional modeling, allows to predict the exact boundaries of the application of the drug, to calculate its required amount and time of movement to the wound. Using 3D computer graphics of discrete objects, methods have been developed to predict the conditions for the reliable functioning of multilayer dressings. Investigated processes of transport and distribution of liquid moisture can be used in the selection of components of the raw material composition, structure and number of layers of multilayer wound dressings, taking into account the real geometric profile of the wound.

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