scholarly journals Chitosan-based biomaterials used in critical-size bone defects: radiographic study in rat's calvaria

2012 ◽  
Vol 41 (5) ◽  
pp. 312-317 ◽  
Author(s):  
Rubens Spin-Neto ◽  
Felipe Leite Coletti ◽  
Rubens Moreno de Freitas ◽  
Chaíne Pavone ◽  
Sérgio Paulo Campana-Filho ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Bone Density ◽  
High Molecular Weight ◽  
Critical Size ◽  
Bone Defects ◽  
Control Group ◽  
Low Molecular Weight ◽  
Chitosan Hydrochloride ◽  
Low Molecular Weight Chitosan ◽  
High Molecular Weight Chitosan

OBJECTIVE: This study evaluated, using digital radiographic images, the action of chitosan and chitosan hydrochloride biomaterials, with both low and high molecular weight, used in the correction of critical-size bone defects (CSBD's) in rat's calvaria. MATERIAL AND METHOD: CSBD's with 8 mm in diameter were surgically created in the calvaria of 50 Holtzman rats and these were filled with a blood clot (Control), low molecular weight chitosan, high molecular weight chitosan, low molecular weight chitosan hydrochloride and high molecular weight chitosan hydrochloride, for a total of 10 animals, which were divided into two experimental periods (15 and 60 days), for each biomaterial. The radiographic evaluation was made using two digital radiographs of the animal's skull: one taken right after the bone defect was created and the other at the moment of the sacrifice, providing the initial and the final radiographic bone density in the area of the defect, which were compared. RESULT: Analysis of radiographic bone density indicated that the increase in the radiographic bone density of the CSBD's treated with the proposed biomaterials, in either molecular weight, in both observed periods, where similar to those found in control group. CONCLUSION: Tested chitosan-based biomaterials were not able to enhance the radiographic density in the CSBD's made in rat's calvaria.

scholarly journals APPROACHES TO THE SELECTION OF EXCIPIENTS FOR DENTAL GEL WITH CETYLPYRIDINIUM CHLORIDE

2021 ◽  
Vol 9 (1) ◽  
pp. 54-63
Author(s):  
E. Yu. Zagorulko ◽  
A. S. Karavaeva
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Cetylpyridinium Chloride ◽  
Poloxamer 407 ◽  
Low Molecular Weight ◽  
Complex Evaluation ◽  
Low Molecular Weight Chitosan ◽  
Penetration Ability ◽  
Osmotic Activity ◽  
High Molecular Weight Chitosan

The aim of the study was to determine the excipients influence on the characteristics of gels with cetylpyridinium chloride and to select the dental gel formulation gelation agents promising for the development of dental gel compositions. Hereby, the properties of the active pharmaceutical ingredient, characteristics of the specific gelation agents, as well as their influence on stability, biopharmaceutical and application properties of gels, were taken into account. Materials and methods. In this study, polymers with various gelation mechanisms were considered. Their compatibility with cetylpyridinium chloride as well as storing kinetic and colloid kinds of stability, pH of aqueous solutions, spreadability and textural properties, a penetration ability by the agar diffusion method, an osmotic activity and rheological properties of the gels, were examined. For a complex evaluation of gel compositions study results, a desirability function was used.Results. Stable homogenous dental gels with cetylpyridinium chloride can be obtained by using 25% poloxamer 407 and 5.0% high molecular weight chitosan as the basis.The addition of poloxamer 188 to high molecular weight chitosan gels can produce stable systems with improved textural characteristics as well as increase their osmotic activity. Agar and low molecular weight chitosan addition significantly decrease, whereas poloxamer188 and various molecular weight polyethyleneglycol increase the osmotic activity of 25 % poloxamer 407 gels which are also characterized by a high penetration ability.Conclusion. A complex evaluation of biopharmaceutical, physicochemical and application properties of the gels made it possible to establish that combinations of poloxamer 407 with polyvinylpyrrolidone, agar, and low molecular weight chitosan, can be recommended as a base for a dental gel with cetylpyridinium chloride.

Perbedaan Pengaruh Aplikasi Gel Kombinasi Kitosan Berat Molekul Tinggi dan Rendah dengan Ekstrak Lidah Buaya (Aloe vera) Terhadap Kepadatan Kolagen pada Proses Penyembuhan Ulkus Traumatikus

DENTA ◽  
2018 ◽  
Vol 12 (1) ◽  
pp. 60
Author(s):  
Sularsih Sularsih ◽  
Michelle Suhartono ◽  
Nafi’ah Nafi’ah
Keyword(s):  
Molecular Weight ◽  
Wound Healing ◽  
High Molecular Weight ◽  
Aloe Vera ◽  
Collagen Fibers ◽  
Control Group ◽  
Low Molecular Weight ◽  
Group I ◽  
Significant Difference ◽  
Low Molecular Weight Chitosan

<p><strong><em>Background:</em></strong><em> Traumatic ulcer is one of the most common oral wounds. Chitosan has mucoadhesive characteristic while Aloe vera containing lignin which is able to penetrate the skin. It is expected that the combined gel of chitosan and Aloe vera will function as wound healing accelerator in traumatic ulcer. Molecular weight is one of the characteristics of chitosan quality. <strong>Purpose:</strong> the aim of this experiment was to know the density of collagen fibers in wound healing of traumatic ulcer using the combined gel of chitosan with different molecular weight and Aloe vera. <strong>Materials and method: </strong>30 Male Rattus Norvegicus were divided into 3 groups. Group I was control group (without chitosan and Aloe vera), group II was given low molecular weight chitosan and Aloe vera, group III was given high molecular weight chitosan and Aloe vera. The groups were given traumatic ulcer making with 4 mm diameter and 2 mm depth. Rats were sacrificed by decapitation on day 3 and 7 then they were examined histopatologically to see the density of collagen fibers. <strong>Result:</strong> Statistical analysis with Kruskall Wallis and Mann-Whitney U test showed that there were significant difference p&lt;0,05 between high and low molecular weight chitosan with Aloe vera group on day 3 and 7. <strong>Conclusion:</strong> Chitosan with high molecular weight and Aloe vera were more effective in wound healing of traumatic ulcer b</em><em>ecause they increase</em><em> the density of collagen fibers.</em><em></em></p><p><strong><em> </em></strong></p><p><strong><em>Keywords:</em></strong><em>  Combined gel of chitosan and Aloe vera, density of collagen fibers, wound healing.</em><em></em></p><p><strong><em> </em></strong></p><strong><em>Korespondensi:</em></strong><em> Sularsih, Bagian Ilmu Biomaterial Kedokteran Gigi, Fakultas Kedokteran Gigi, Universitas Hang Tuah, Arif Rahman Hakim 150, Telepon 031-5912191.</em>

scholarly journals Synthesis of High Molecular Weight Chitosan from Chitin by Mechanochemistry and Aging

2019 ◽  
Author(s):  
Thomas Di Nardo ◽  
Caroline Hadad ◽  
Albert Nguyen Van Nhien ◽  
Audrey Moores
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Magic Angle Spinning ◽  
Low Molecular Weight ◽  
Magic Angle ◽  
Energy Usage ◽  
Molecular Weights ◽  
Low Molecular Weight Chitosan ◽  
Angle Spinning ◽  
High Molecular Weight Chitosan

Chitosan can be obtained from the deacetylation of chitin. This process is however difficult and usually accompanied by depolymerization, affording low molecular weight chitosan. We report a novel path, relying on a combination of mechanochemitry and aging, to afford high molecular weight chitosan with minimal use of energy and solvent. This method is versatile and applicable to a number of chitin sources, including crude crustaceans and insect shells, yielding deacetylation up to 98% and remarkably high molecular weights. Chitin deacetylation was measured by magic angle spinning nuclear magnetic resonance and molecular weight by viscometry. This process affords chitosan in a safer fashion and with less materials and energy usage than the classic hydrothermal one.

scholarly journals Synthesis of High Molecular Weight Chitosan from Chitin by Mechanochemistry and Aging

2019 ◽  
Author(s):  
Thomas Di Nardo ◽  
Caroline Hadad ◽  
Albert Nguyen Van Nhien ◽  
Audrey Moores
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Magic Angle Spinning ◽  
Low Molecular Weight ◽  
Magic Angle ◽  
Energy Usage ◽  
Molecular Weights ◽  
Low Molecular Weight Chitosan ◽  
Angle Spinning ◽  
High Molecular Weight Chitosan

Chitosan can be obtained from the deacetylation of chitin. This process is however difficult and usually accompanied by depolymerization, affording low molecular weight chitosan. We report a novel path, relying on a combination of mechanochemitry and aging, to afford high molecular weight chitosan with minimal use of energy and solvent. This method is versatile and applicable to a number of chitin sources, including crude crustaceans and insect shells, yielding deacetylation up to 98% and remarkably high molecular weights. Chitin deacetylation was measured by magic angle spinning nuclear magnetic resonance and molecular weight by viscometry. This process affords chitosan in a safer fashion and with less materials and energy usage than the classic hydrothermal one.

scholarly journals Reproductive and Behavioral Evaluation of a New Immunocastration Dog Vaccine

Animals ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 226
Author(s):  
Daniela Siel ◽  
María José Ubilla ◽  
Sonia Vidal ◽  
Alexandra Loaiza ◽  
John Quiroga ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Recombinant Protein ◽  
Control Group ◽  
Low Molecular Weight ◽  
Specific Antibodies ◽  
Controlled Conditions ◽  
Low Molecular Weight Chitosan ◽  
And Control ◽  
Complementary Strategy ◽  
Positive Effect

Canine immunocastration development has been of interest for many years as a complementary strategy to surgical castration. The purpose of this paper was to verify the effect of a recombinant vaccine for dog immunocastration. Two tests were done, one under controlled conditions and a second under field conditions. Animals were injected with 1 mL of 500 µg GnRXG/Q recombinant protein; 500 µg of low molecular weight chitosan as adjuvant; 1 mL NaCl 0.9% q.s. In the first trial, eight Beagle male dogs between the ages of 1 and 3 comprised the sample, randomly divided into two groups: vaccinated group (n = 7) and control group (n = 2). The second trial had 32 dogs with owners. In the first controlled conditions trial, the vaccine produced specific antibodies that remained until the end of the trial (day 270), inducing reduced testosterone and spermiogram changes in the immunized animals. In a second trial, on the field, specific immunity was induced, which remained high up to day 150. The vaccine also reduced sexual agonistic and marking behaviors. This new vaccine proved to be safe, immunogenic, capable of reducing gonadal functionality, and had a positive effect on inducing reduced sexual, agonistic, and marking behavior of the animals.

scholarly journals Antibacterial activity of high-molecular-weight and low-molecular-weight chitosan upon oral pathogens

2019 ◽  
Vol 22 (2) ◽  
pp. 169 ◽  
Author(s):  
Niloofar Jenabian ◽  
Zeinab Abedian ◽  
AliAkbar Moghadamnia ◽  
Ebrahim Zabihi ◽  
Hamed Tashakorian ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Antibacterial Activity ◽  
High Molecular Weight ◽  
Low Molecular Weight ◽  
Low Molecular Weight Chitosan ◽  
Oral Pathogens

Researches on the Fixation Performance of Chitosan and its Derivative

2012 ◽  
Vol 535-537 ◽  
pp. 1547-1551
Author(s):  
Ning Ning Lei ◽  
Na Zhong ◽  
Yi Dong Shi ◽  
Xiao Rui Ling
Keyword(s):  
Molecular Weight ◽  
Infrared Spectrum ◽  
High Molecular Weight ◽  
Reactive Dyes ◽  
Cross Linking ◽  
Low Molecular Weight ◽  
Chitosan Hydrochloride ◽  
Dyed Fabrics ◽  
Dyed Fabric ◽  
Different Molecular Weight

The fixing performance of chitosan hydrochloride (CSH) with different molecular weight and chitosan biguanide hydrochloride (CSGH) as a fixing agent for cotton fabric dyed with reactive dyes was discussed. The results showed that the fixing effects of CSH on reactive dyes were related to its molecular weight, and the CSH with high molecular weight (HMW) exhibited better fixing effects than that with low molecular weight (LMW). The fixing effects of CSGH on reactive dyes were superior to that of the CSH with HMW, because of the CSGH molecule with positive charges and the imino groups, which could further strengthened the interaction among the CSGH, dyes and cellulose molecules. After treated by the CSGH, the soaping, perspiration and dry rubbing fastness of the dyed fabrics could be increased 0.5 to 1 grade, while the wet rubbing fastness of ones was also improved obviously. The infrared spectrum (FTIR) of the dyed fabric treated by CSGH showed that a cross-linking was formed among CSGH, dyes and cellulose molecules.

scholarly journals Manufacturing technology of low-molecular-weight chitosan based on enzymatic hydrolysis

2021 ◽  
Author(s):  
E.I. Kovaleva ◽  
A.I. Albulov ◽  
M.A. Frolova ◽  
V.P. Varlamov ◽  
A.V. Grin
Keyword(s):  
Molecular Weight ◽  
Biological Activity ◽  
Enzymatic Hydrolysis ◽  
Aqueous Solutions ◽  
High Molecular Weight ◽  
The Body ◽  
Low Molecular Weight ◽  
High Molecular Weight Polymer ◽  
Low Molecular Weight Chitosan ◽  
Chitin And Chitosan

Chitosan is natural high molecular weight polymer of D-glucosamine and N-acetyl - D - glucosamine connected by 1,4 - b - glycoside bond with a molecular mass of 1000 kDa (and above), practical use is difficult because of high viscosity of its aqueous solutions even at low concentrations, and lack of solubility at neutral pH and, consequently, low biological activity. To reduce viscosity, improve the solubility and enhance biological activity of high molecular weight chitosan subjected to depolymerization. Chitosan, like other polysaccharides, is characterized by a hydrolysis reaction, which is due to the presence of glycoside bonds in the molecule that are lable to hydrolyzing agents, for example, aqueous solutions of acids, alkalis, as well as to the effect of some hydrolases. During hydrolysis, glycoside bonds are broken and, as a result, the molecular weight of chitosan decreases. However, these processes are accompanied by the formation of significant amounts of toxic products and require very costly disposal of waste before it is discharged into the environment. Chitin and chitosan are natural biopolymers and their synthesis, modification and degradation are associated with enzymatic transformations. It is the biodegradability to the usual substances for the body that is one of the main advantages of chitosan. It is obvious that the most appropriate method is the enzymatic hydrolysis of chitosan. As enzyme preparations for the degradation of chitin and chitosan, enzyme complexes of various origins are used. These can be enzymes from crab or krill hepatopancreas complexes, as well as pancreatin from the pancreas of cattle. But more often for this purpose, enzymes complexes with chitinolytic activity of microbiological origin are used. In this study, low-molecular-weight chitosan was obtained by enzymatic hydrolysis using the extracellular chitinolytic complex of Streptomyces kurssanovii. The resulting chitosan had a medium-viscosity molecular weight of 25-40 kDa. Carrying out two stages of fractionation (stepwise acidification and separation on membranes) made it possible to obtain chitosan fractions with a narrow distribution by molecular weight.

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