Structure and interactions in chitosan hydrogels formed by complexation or aggregation for biomedical applications

Berger, Julia; Reist, Marianne; Mayer, Joachim M.; Felt, O.; Gurny, Robert

doi:10.1016/s0939-6411(03)00160-7

Cited by 889 publications

(594 citation statements)

References 139 publications

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“…19,20) Hydrogels provide a cover on the wound in the absence of injured skin integrity. An ideal gel formulation used for burn healing should be easily applicable and retained for a long time on the wound.…”

Section: Resultsmentioning

confidence: 99%

Preparation of Fucoidan-Chitosan Hydrogel and Its Application as Burn Healing Accelerator on Rabbits

Sezer

Cevher

Hatıpoğlu

et al. 2008

Biological & Pharmaceutical Bulletin

160

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Burn healing includes a specific biological process related to the general phenomenon of growth and regeneration and the primary objective in burn care is the promotion of rapid wound healing with the best functional results. The principal function of a burn dressing is to provide an optimum healing milieu for natural healing and desirable burn dressing may, therefore, be characterized on the basis of its performance such as; (a) provision of adequate gaseous exchange, (b) provision and maintenance of a moist environment, (c) protection from infections and contamination, (d) absorption of wound fluids and (e) painless and easy removal. 1,2) Hydrogels are ideal biopolymeric pharmaceutical forms for the treatment of skin wounds. They have low interfacial tension, high molecular and oxygen permeability, good moisturizing and mechanical properties that resemble physiological soft tissue. 3,4) For this reasons, polysaccharides, e.g. chitosan, are having hydrogel forming properties have been considered to be advantageous in its application as a wound dressing material. 5) Chitosan, [a (1→4) 2-amino-2-deoxy-b-D-glucan], a unique polysaccharide derived from deacetylation of chitin, has been used in wound treatment owing to its good biocompatibility, biodegradability and accelerated granulation. [6][7][8] On the other hand, fucoidan is a sulphated polyfucose polysaccharide and has attracted considerable biotechnological research interest since the discovery that it possessed anti-coagulant activity similar to that of heparin and also reported to possess other properties including antithrombotic, anti-inflammatory, anti-tumoral and anti-viral effects. 9,10) Many of these effects are thought to be due to its interaction with growth factors such as basic fibroblast growth factor (bFGF) and transforming growth factor-b (TGF-b). Fucoidan may, therefore, be able to modulate growth factordependent pathways in the cell biology of tissue repair. 11) Although a great number of studies on different pharmacological properties of fucoidan and chitosan are present, there is little information on the fucoidan-based system used in burn healing and its only limited with cell culture. 12) The aim of this study was to prepare fucoidan-chitosan hydrogel and to investigate its treatment efficiency on dermal burns on rabbits. MATERIALS AND METHODSMaterials Chitosan (MW 250 kDa, deacetylation degree Ն90%, Pronova A/S, Norway; MW 400 kDa, deacetylation degree Ն60%, Fluka, Germany; MW 750 kDa, deacetylation degree Ն75%, Sigma, U.S.A.), Fucoidan (from Fucus vesiculosus) and lactic acid (85% m/v) purchased from Sigma, U.S.A. All other reagents used were of analytical grade.Preparation of Hydrogels The composition of gel formulations was given in Table 1. Fucoidan was dissolved in 1% m/v lactic acid solution by mechanical shaking at 300 rpm for 1 h. Then chitosan was left to swell in the fucoidan solution overnight to prepare hydrogels. 13) Formulations were kept at 4°C until experiment.Viscosity Measurement The viscosity of hydrogels was determine...

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Section: Resultsmentioning

confidence: 99%

Preparation of Fucoidan-Chitosan Hydrogel and Its Application as Burn Healing Accelerator on Rabbits

Sezer

Cevher

Hatıpoğlu

et al. 2008

Biological & Pharmaceutical Bulletin

160

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“…1). Side chains could be covalently linked to the C-2 free amino groups in deacetylated units or to the hydroxyl groups in the C-3 and C-6 carbons either of acetylated or deacetylated units (Lloyd et al, 1998;Berger et al, 2004). They are formed by the arrangement of the HEMA and AA monomers either in blocks or randomly.…”

Section: Resultsmentioning

confidence: 99%

“…Chitosan can enhance blood coagulation by an independent mechanism of the classical coagulation cascade and appear to be an interaction between negative charges of cell membranes of erythrocytes and positive charges of chitosan filaments (Rao and Sharma, 1997;Okamoto et al, 2003). One hypothesis advanced to explain the ability of chitosan to enhance wound healing is related to its biodegradability (Berger et al, 2004). Lysozyme, normally produced by macrophages, hydrolyses chitosan and its derivatives to oligomers, which activate macrophages to produce nitric oxide, activated oxygen species, tumor necrosis factor-␣, interferon and interleukin-1.…”

Section: Introductionmentioning

confidence: 99%

“…The modification of polymeric materials by graft copolymerization has been studied deeply by several authors (Kurika, 1996;Harish Prashanth and Tharanathan, 2003;Sashiwa and Aiba, 2004) because it can provide materials with desired properties through the appropriate choice of the molecular characteristics of the side chain to be grafted (Casimiro et al, 2005). Chitosan bears two types of reactive groups that can be modified by grafting: the C-2 free amino groups on deacetylated units and the hydroxyl groups in the C-3 and C-6 either in acetylated or deacetylated units (Lloyd et al, 1998;Berger et al, 2004) (Fig. 1).…”

Section: Introductionmentioning

confidence: 99%

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Synthesis and characterization of membranes obtained by graft copolymerization of 2-hydroxyethyl methacrylate and acrylic acid onto chitosan

Santos

Coelho

Ferreira

et al. 2006

International Journal of Pharmaceutics

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Chitosan based membranes to be applied on wound healing as topical drug delivery systems were developed by graft copolymerization of acrylic acid (AA) and 2-hydroxyethyl methacrylate (HEMA) onto chitosan using cerium ammonium nitrate as chemical initiator. Evidence for graft copolymerization of the vinyl monomers onto chitosan was obtained by FTIR and DMTA. Swelling degree, cytotoxicity, thrombogenicity and haemolytic activity of these membranes were evaluated. Chitosan-graft-AA-graft-HEMA showed to be the best matrix for drug delivery systems than chitosan-graft-AA because it retains good swelling properties, but the content in HEMA has improved cytocompatibility, hemocompatibility and thrombogenic character.

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“…CS is a hydrogel polymer, so CS nanoparticle clusters tend to be formed by self-adhesion through Brownian motion among nanoparticles themselves. In addition, intra-or intermolecular hydrogen tends to lead intra-or intermolecular aggregation of particles in polar solvent (Berger, Reist, Mayer, Felt, & Gurny, 2004) As the aggregates of nanoparticles are above one micron (seen by SEM), the actual size of them cannot be measured properly by the DLS and therefore, the size of aggregates was determined using a Mastersizer. The median diameter (D [v,50]) of the aggregates varied between 3.7 and 4.7 µm (Table 3.3), which are within the respirable range (<5µm) and suitable for DPI formulations.…”

Section: Preparation Of Nanoparticlesmentioning

confidence: 99%

Development of Nicotine Loaded Chitosan Nanoparticles for Lung Delivery

Wang¹

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Cigarette smoking has become one of the leading causes of preventable deaths all over the world, causing a serious threat to human wellbeing and a tremendous economic burden to governments. The currently available treatment options for smoking cessation are not efficient. The pulmonary delivery of drugs by methods such as dry powder inhaler (DPI) has been recognized as one of the most efficient routes of drug delivery to the targeted area. The lung delivery of nicotine in this way would be expected to mimic the effects of tobacco smoking and could significantly reduce the negative health effects of smoking that result from nicotine addiction.The aim of this study is to develop nanoparticles with controlled physicochemical properties using biodegradable polymer of chitosan (CS) loaded with nicotine salt for pulmonary delivery as DPI formulations. The outcomes of this project are expected to be a safe and effective CS-based nicotine formulation for pulmonary delivery to treat nicotine dependence. This thesis specially addresses the research questions: (1) how to develop a feasible process to manufacture the nanoparticles suitable for pulmonary drug delivery using biodegradable polymer of CS containing nicotine salt; (2) how to develop an animal model for pulmonary drug delivery from DPI formulation using a nose-only inhalation device.The current therapeutic options for treatment of smoking addiction have been reviewed, and current advancements of technology in pulmonary drug delivery are summarised. Buccal administration of drugs exhibits a low oral bioavailability, and sublingual tablets and chewing gums can be swallowed before being absorbed.Although nasal spray of nicotine is a fast way to deliver nicotine into the bloodstream, Development of Nicotine Loaded Chitosan Nanoparticles for Lung Delivery iii the rate of absorption is still not as rapid as cigarette smoking. Therefore, it is proposed that delivery of nicotine with sustained drug release profile direct into the deep lung is likely to more effectively mimic the rapid effects of cigarette smoking on a physiological level, which could eliminate patient craving and allow the tapering of nicotine level over time to improve patients' compliance.Water in oil (w/o) emulsion crosslinking method has been used to fabricate nicotine hydrogen tartrate (NHT)-loaded CS nanoparticles which separate as solid microaggregates. The physicochemical properties of particles are characterized by a series of techniques. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) shows that the prepared particles are spherical in morphology with rough surface after loading CS particles with NHT. Dynamic Light Scattering (DLS)by Zetasizer determined nanoparticle size ranging from 167.6 nm to 411 nm, while DLS by Mastersizer demonstrated that the microaggregates of these nanoparticles are in the respirable range (<5µm). The surface positive charge as measured by zeta potential tends to decrease with increase of mass ratios of NHT to CS, which is in contr...

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Structure and interactions in chitosan hydrogels formed by complexation or aggregation for biomedical applications

Cited by 889 publications

References 139 publications

Preparation of Fucoidan-Chitosan Hydrogel and Its Application as Burn Healing Accelerator on Rabbits

Preparation of Fucoidan-Chitosan Hydrogel and Its Application as Burn Healing Accelerator on Rabbits

Synthesis and characterization of membranes obtained by graft copolymerization of 2-hydroxyethyl methacrylate and acrylic acid onto chitosan

Development of Nicotine Loaded Chitosan Nanoparticles for Lung Delivery

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