The effect of chitosan, a carbohydrate biopolymer extracted from chitin, on periodontal regeneration is of particular interest. The purpose of this study was to evaluate the effect of chitosan on primary rat calvarial cells in vitro, with special focus on their proliferative properties by cell activity and the amount of total protein synthesis. The experimental groups were cultured with chitosan in concentration of 0.01, 0.1, 1.0, 2.0 and 5.0 mg/ml for MTT assay. In the experimental groups, cells were cultured with chitosan in concentration of 0.01, 0.1, 1.0 and 2.0 mg/ml. Each group was characterized by examining alkaline phosphatase activity at 3 and 7 days and the ability to produce mineralized nodules of rat calvarial cells at 14 and 21 days. The results were as follows: 1. The cell activity was not reduced in the concentration of 0.01~1.0 mg/ml whereas the cell activity was reduced in the concentration of 5.0 mg/ml than the control at day 1 and 3 (p<0.05). 2. Primary rat calvarial cells treated with chitosan in the concentration 0.01 mg/ml and 0.1 mg/ml showed more protein synthesis than the control at day 3 (p<0.01). But primary rat calvarial cells treated with chitosan showed more protein synthesis than in control but they didn't have statistically difference among groups at day 7. 3. At 3 and 7 days, alkaline phosphatase activity was significantly increased in the concentration of 0.01 mg/ml. 0.1 mg/ml and 1.0 mg/ml (p<0.05). 4. The percentage of mineralized bone nodule was more in the concentration of chitosan 0.1 mg/ml and 1.0 mg/ml than the control. These results suggested that chitosan has a positive effect on the bone formation of primary rat calvarial cells in the concentration of 0.1 mg/ml and 1.0 mg/ml.
Alkaline Phosphatase ; Animals ; Biopolymers ; Chitin ; Chitosan* ; Osteogenesis ; Rats* ; Regeneration

The major goals of periodontal therapy is the functional regeneration of periodontal supporting structures already destructed by periodontal disease as well as the reduction of signs and symptoms of progressive periodontal disease. There have been many efforts to develop materials and therapeutic methods to promote periodontal wound healing. There have been increasing interest on the chitosan made by chitin. Chitin is second only to cellulose as the most abundant natural biopolymer. It is a structural component of the exoskeleton of invertebrates(e.g., shrimp, crabs, lobsters), of the cell wall of fungi, and of the cuticle of insects. Chitosan is a derivative of chitin made by deacetylation of side chains. Many experiments using chitosan in various animal models have proven its beneficial effects. The aim of this study is to evaluate the osteogenesis of chitosan on the calvarial critical size defect in Sprague Dawley rats. An 8 mm surgical defect was produced with a trephine bur in the area of the midsagittal suture. The rats were divided into two groups: Untreated control group versus experimental group with 50mg of soluble chitosan gel. The animals were sacrificed at 2, 4 and 8 weeks after surgical procedure. The specimens were examined by histologic, histomorphometric and radiodensitometric analyses. The results are as follows: 1. The length of newly formed bone in the defects was 102.91+/-25.46micrometer, 219.46+/-97.81micrometer at the 2 weeks, 130.95+/-39.24micrometer, 212.39+/-89.22micrometer at the 4 weeks, 181.53+/-76.35micrometer and 257.12+/-51.22micrometer at the 8 weeks in the control group and experimental group respectively. At all periods, the means of experimental group was greater than those of control group. But, there was no statistically significant difference between the two groups. 2. The area of newly formed bone in the defects was 2962.06+/-1284.48micrometer2, 5194.88+/-1247.88micrometer2 at the 2 weeks, 5103.25+/-1375.88micrometer2, 7751.43+/-2228.20micrometer2 at the 4 weeks and 8046.02+/-818.99micrometer2, 15578.57+/-5606.55micrometer2 at the 8 weeks in the control group and experimental group respectively. At all periods, the means of experimental group was greater than those of control group. The experimental group showed statistically significant difference to the control group at the 2 and 8 weeks. 3. The density of newly formed bone in the defects was 14.26+/-6.33%, 27.91+/-6.65% at the 2 weeks, 20.06+/-9.07%, 27.86+/-8.20% at the 4 weeks and 22.99+/-3.76%, 32.17+/-6.38% at the 8 weeks in the control group and experimental group respectively. At all periods, the means of experimental group was greater than those of control group. The experimental group showed statistically significant difference to the control group at the 2 and 8 weeks. These results suggest that the use of chitosan on the calvarial defects in rats has significant effect on the regeneration of bone tissue in itself
Animals ; Biopolymers ; Bone and Bones ; Cell Wall ; Cellulose ; Chitin ; Chitosan* ; Fungi ; Insects ; Models, Animal ; Osteogenesis ; Periodontal Diseases ; Rats ; Rats, Sprague-Dawley* ; Regeneration ; Sutures ; Wound Healing

Periodontal therapy has dealt primarily with attempts at arresting progression of disease, however, more recent techniques have focused on regenerating the periodontal ligament having the capacity to regenerate the periodontium. The effect of chitosan(poly-N-acetyl glucosaminoglycan), a carbohydrate biopolymer extracted from chitin, on periodontal ligament regeneration is of particular interest. The purpose of this study was to evaluate the effect of chitosan on the human periodontal ligament fibroblasts(hPDLFs) in vitro, with special focus on their proliferative properties by MTT assay, the synthesis of type I collagen by reverse transcription-polymerase chain reaction(RT-PCR) and the activity of alkaline phosphatase(ALP). Fibroblast populations were obtained from individuals with a healthy periodontium and cultured with alpha-MEM as the control group. The experimental groups were cultured with chitosan in concentration of 0.01, 0.1, 1, 2mg/ml. The results are as follows; 1. Chitosan-induced proliferative responses of hPDLFs reached a plateau at the concentration of 0.1mg/ml (p<0.05). 2. When hPDLFs were stimulated with 0.1mg/ml chitosan, mRNA expression of type I collagen was up-regulated. 3. When hPDLFs were stimulated with 0.1mg/ml chitosan, ALP activity was significantly upregulated(p<0.05). In summary, chitosan(0.1mg/ml) enhanced the type I collagen synthesis in the early stage, and afterwards, facilitated differentiation into osteogenic cells. The results of this in vitro experiment suggest that chitosan potentiates the differentiation of osteoprogenitor cells and may facilitate the formation of bone.
Biopolymers ; Chitin ; Chitosan* ; Collagen Type I ; Fibroblasts* ; Humans* ; Periodontal Ligament* ; Periodontium ; Regeneration ; RNA, Messenger

BACKGROUND: Biopolymeric in situ hydrogels play a crucial role in the regenerative repair and replacement of infected or injured tissue. They possess excellent biodegradability and biocompatibility in the biological system, however only a few biopolymeric in situ hydrogels have been approved clinically. Researchers have been investigating new advancements and designs to restore tissue functions and structure, and these studies involve a composite of biometrics, cells and a combination of factors that can repair or regenerate damaged tissue. METHODS: Injectable hydrogels, cross-linking mechanisms, bioactive materials for injectable hydrogels, clinically applied injectable biopolymeric hydrogels and the bioimaging applications of hydrogels were reviewed. RESULTS: This article reviews the different types of biopolymeric injectable hydrogels, their gelation mechanisms, tissue engineering, clinical applications and their various in situ imaging techniques. CONCLUSION: The applications of bioactive injectable hydrogels and their bioimaging are a promising area in tissue engineering and regenerative medicine. There is a high demand for injectable hydrogels for in situ imaging.
Biopolymers* ; Hydrogel* ; Hydrogels* ; Regenerative Medicine ; Tissue Engineering*

Chitosan, which is a biopolymer, composed of glucosamine units linked by beta-1, 4 glycoside bonds, is rich in shells of crustacean such as crabs and shrimps. Consumption of chitosan has been rapidly increased as a functional food. We examined effects of chitosan on the damages caused by lead (Pb) exposure in rats. Male Sprague-Dawley rats were divided into 8 groups (n = 64), then fed diets containing 3% cellulose (control) or 3% chitosan, each with 4 different lead doses (0 mg/d, 20 mg/d, 50 mg/d, and 100 mg/d) for 4 wks. Lead doses were given 3 times per week by oral administration. Blood lead levels in rats increased depending on the administered doses of lead. Rats fed chitosan diets showed lower blood lead concentration than did their respective controls. Effect of chitosan on the blood lead was more beneficial in rats exposed to lower lead (20 mg/d) than in rats exposed to higher lead (50 mg/d and 100 mg/d). Histological changes in erythrocytes and liver were also examined. Chitosan tended to reduce numbers of basophilic stippling erythrocytes and improve the histological liver changes in rats given various lead doses. The preventive effects of chitosan on liver damages were stronger in rats with higher lead than those with lower lead. These results indicate that chitosan has beneficial effects on both blood toxicological responses and histological damages of erythrocytes and liver induced by the administration of various lead doses.
Administration, Oral ; Animals ; Basophils ; Biopolymers ; Cellulose ; Chitosan* ; Diet ; Erythrocytes ; Functional Food ; Glucosamine ; Humans ; Liver ; Male ; Rats* ; Rats, Sprague-Dawley

The purpose of this study was to investigate and compare the biomechanical properties of orthodontic rubber elastic materials. Latex bands, nylon-covered elastic threads and polyurethane-based elastic modules, delivering 205 +/- 10 grams force at 30mm stretching state were selected and stored separately in 3 environments-air (22+/-3degreesC), distilled water (37+/-1degreesC), or natural saliva (37+/-1degreesC). And, the amount of remaining force and permanent elongation of each sample were measured on Instron at interval of 1 hour, 6 hours, 12 hours, 24 hours, 1 week, and 2 weeks. So the data derived were analyzed statistically. The results were as follows: 1. Force decay and permanent elongation of all materials increased with time lapsed; elastic module, latex band and nylon-covered elastic thread in that order of the amount of force decay; elastic module, elastic thread, latex band in that order of the amount of permanent elongation. 2. Among environmental conditions, force decay and permanent elongation in natural saliva, most increased, and those in air, least increased. 3. There was a negative correlation between force decay and permanent elongation. 4. Force decay and permanent elongation were most affected by the material itself, time and environments in that order. 5. After 24 hours in saliva, the percentage of remaining force in elastic module was 51.9% (107.37grams); in latex band, 83.2%(172.62grams); in elastic thread, 85.0%(179.25grams). After 2 weeks in saliva, the percentage of remaining force in elastic module was 42.9%(88.75grams); in latex band, 74.5%(154.50grams); in elastic thread, 77.6%(163.75grams).
Latex ; Rubber* ; Saliva ; Water

Stomach ; Rubber ; Latex

Periodontal therapy has dealt primarily with attempts at arresting progression of disease, however, more recent techniques have focused on regenerating the periodontal ligament having the capacity to regenerate the periodontium. The effect of chitosan, a carbohydrate biopolymer extracted from chitin, on periodontal ligament regeneration is of particular interest. The purpose of this study was to evaluate the effect of chitosan on the expression of extracellular matrix proteins in primary rat calvarial cells in vitro. In the control group, cells was cultured with BGJb media. In the experimental groups, cells were cultured with chitosan in concentration of 0.01, 0.1, 1.0 and 2.0 mg/ml. Then each group was characterized by examining alkaline phosphatase activity at 3 and 7 days, and the ability to produce mineralized nodules of rat calvarial cells at 14 and 21 days. Synthesis of type I collagen (COL-I), osteocalcin (OCN), bone sialoprotein (BSP) was evaluated by RT-PCR at 14 days. The results were as follows: 1. Alkaline phosphatase activity was significantly higher in the concentration of chitosan 0.01mg/ml, 0.1mg/ml and 1.0mg/ml compared to control (p<0.05). 2. The percentage of mineralized bone nodule was more in the concentration of chitosan 0.1mg/ml and 1.0 mg/ml than the control. 3. At 14 day culture, the expression of OCN was increased by chitosan in concentration of 1.0 mg/ml and 2.0 mg/ml. These results suggested that chitosan in concentration of 0.1 and 1.0 mg/ml stimulate the extracellular matrix of primary rat calvarial cells and may facilitate the formation of bone.
Alkaline Phosphatase ; Animals ; Biopolymers ; Bone Matrix* ; Chitin ; Chitosan* ; Collagen Type I ; Extracellular Matrix ; Extracellular Matrix Proteins ; Integrin-Binding Sialoprotein ; Osteocalcin ; Periodontal Ligament ; Periodontium ; Rats* ; Regeneration

AIMTo investigate the formation mechanism, macromolecular drug loading capacity and release property of alginate-chitosan microcapsules (ACM).

METHODSACM was prepared by emulsification-gelation method and its formation mechanism was studied by DSC analysis. Using bovine serum albumin (BSA) as model drug, the drug loading and release properties of the microcapsules on macromolecular drug were investigated.

RESULTSThe results of DSC analysis showed that there is electrostatic interaction between materials encapsulated in the microcapsule. With the increase of BSA microcapsule ratio, the BSA loading percentage rose from 9.20% to 35.08%; and with the ascent of chitosan (CTS) concentration, the BSA loading percentage increased from 30.29% to 38.12%. The BSA microcapsules whowed a two-phase release in both 0.1 mol.L-1 HCl and phosphate buffer saline (pH 7.4). With the increase of CTS concentration, the BSA release more and more slowly in 0.1 mol.L-1 HCl.

CONCLUSIONSpheric and well-dispersed alginate-chitosan microcapsules were prepared. The microcapsule showed good loading capacity to BSA as well as sustained release to a certain degree.

Alginates ; chemistry ; Biopolymers ; Calorimetry, Differential Scanning ; Capsules ; Chitin ; analogs & derivatives ; chemistry ; Chitosan ; Delayed-Action Preparations ; Drug Carriers ; Drug Delivery Systems ; Serum Albumin, Bovine ; administration & dosage ; Technology, Pharmaceutical ; methods

Hypolipidemic effect of biopolymers extracted from culture broth (CP), mycelia (MP), and fruiting bodies (FP) of Auricularia auricula-judae was investigated in dietary-induced hyperlipidemic rats. The experimental animals were administrated (100 mg/kg body weight) with different biopolymers, daily for 4 weeks. Hypolipidemic effects were achieved in all the experimental groups, however, FP was proved to be the most potent one. The administration of the FP reduced the plasma triglyceride, total cholesterol, low-density lipoprotein cholesterol, and atherogenic index by 24.3, 28.5, 36.4, and 40.9%, respectively, while increased the high-density lipoprotein cholesterol level (9.0%), when compared to the saline (control) administered group.
Animals ; Biopolymers* ; Cholesterol ; Fruit* ; Lipoproteins ; Plasma ; Rats* ; Triglycerides