Pharmacokinetics and Biodegradation Performance of a Hydroxypropyl Chitosan Derivative

Hydroxypropyl chitosan(HP-chitosan) has been shown to have promising applications in a wide range of areas due to its biocompatibility, biodegradability and various biological activities, especially in the biomedical and pharmaceutical fields. However, it is not yet known about its pharmacokinetics and biodegradation performance, which are crucial for its clinical applications. In order to lay a foundation for its further applications and exploitations, here we carried out fluorescence intensity and GPC analyses to determine the pharmacokinetics mode of fluorescein isothiocyanate-labeled HP-chitosan(FITC-HP-chitosan) and its biodegradability. The results showed that after intraperitoneal administration at a dose of 10 mg per rat, FITC-HP-chitosan could be absorbed rapidly and distributed to liver, kidney and spleen through blood. It was indicated that FITC-HP-chitosan could be utilized effectively, and 88.47% of the FITC-HP-chitosan could be excreted by urine within 11 days with a molecular weight less than 10 k Da. Moreover, our data indicated that there was an obvious degradation process occurred in liver(< 10 k Da at 24 h). In summary, HP-chitosan has excellent bioavailability and biodegradability, suggesting the potential applications of hydroxypropyl-modified chitosan as materials in drug delivery, tissue engineering and biomedical area.

Immobilization of microorganisms using carrageenan gels coated with chitosan and application to biodegradation of 4-chlorophenol

A new cell immobilization method based on the replacement of KCl by KCl+chitosan as the gelling agent was developed. The experimental results showed that through addition of chitosan into gelling agent, the mechanical strength and the thermal stability of the carrageenan gel were greatly improved. The new immobilization method was used to entrap a chlorophenol degrading microorganism. The immobilized microbial cells were applied for chlorophenol biodegradation. The experiments demonstrated that immobilized cells exhibit a higher bioactivity in the degradation of chlorophenol than free cells.

Pharmacokinetics and Biodegradation of Chitosan in Rats

Chitosan, an excellent biomedical material, has received a widespread in vivo application. In contrast, its metabolism and distribution once being implanted were less documented. In this study, the pharmacokinetics and biodegradation of fluorescein isothiocyanate(FITC) labeled and muscle implantation administrated chitosan in rats were investigated with fluorescence spectrophotometry, histological assay and gel chromatography. After implantation, chitosan was degraded gradually during its distribution to diverse organs. Among the tested organs, liver and kidney were found to be the first two highest in chitosan content, which was followed by heart, brain and spleen. Urinary excretion was believed to be the major pathway of chitosan elimination, yet 80% of chitosan administered to rats was not trackable in their urine. This indicated that the majority of chitosan was degraded in tissues. In average, the molecular weight of the degradation products of chitosan in diverse organs and urine was found to be <65 k Da. This further confirmed the in vivo degradation of chitosan. Our findings provided new evidences for the intensive and safe application of chitosan as a biomedical material.

PREPARATION AND PROPERTIES OF CHITOSAN/LIGNIN COMPOSITE FILMS

Biodegradable composite films based on chitosan and lignin with various composition were prepared via the solution-casting technique.FT-IR results indicate the existence of hydrogen bonding between chitosan and lignin,and SEM images show that lignin could be well dispersed in chitosan when the content of lignin is below 20 wt%due to the strong interfacial interaction.As a result of strong interaction and good dispersion,the tensile strength,storage modulus,thermal degradation temperature and glass transitio...

Synthesis and Characterization of a Hydroxyethyl Derivative of Chitosan and Evaluation of Its Biosafety

Hydroxyethyl chitosan （HE-chitosan） is a water-soluble derivative of chitosan with many apparent biological properties. For example, it is non-toxic and rapidly biodegradable. Moreover, HE-chitosan has advantages in water-solubility, moisture retention and gelling property due to its hydroxyethyl group. However, the biocompatibility and biodegradability of this multifimctional de- rivative have rarely been documented although they are critical for its application in biomedical and clinical treatments. The purpose of this work was to evaluate the biosafety of HE-chitosan, and draw important clues for its diverse applications. HE-chitosan was synthesized and characterized its chemical structure with FTIR. Its molecular weight （Mw） was determined by gel permeation chro- matography （GPC）, and its deacetylation degree （DD） was investigated through potentiometric analysis. The cytotoxicity of HE-chitosan on mouse fibroblast cell L929 was tested. The biocompatibility and biodegradability of HE-chitosan in rat and rabbit were evaluated. The FTIR results indicated that the hydroxyethyl groups were linked to C6 of chitosan. The GPC analysis confirmed that its Mw was about 90.01 kDa. It was also demonstrated that HE-chitosan had excellent biocompatibility and biodegradability in vivo and had no cytotoxicity on L929. These findings indicated that HE-chitosan can potentially be applied as a biomaterial in tissue engineering, drug delivery, and other biomedical fields.

Ectopic osteogenesis and scaffold biodegradation of tissue engineering bone composed of chitosan and osteo-induced bone marrow mesenchymal stem cells in vivo

Background Chitosan （CS） scaffolds combined with osteogenically induced bone marrow mesenchymal stem cells （BMSCs） have been proved to be promising substitutes for repairing bone defects.Nevertheless,the bone-forming and scaffold-biodegrading processes are seldom studied.This study aimed to determine the osteogenic ability of CS/osteoinduced BMSC composites by observing the bone-forming process and explore the relationship between bone formation and scaffold biodegradation.Methods The CS/osteo-induced BMSC composites （CS＋cells group） and the CS scaffolds （CS group） were,respectively,implanted into SD rat thigh muscles.At 2,4,6,8,and 12 weeks postoperatively,the rat femurs were scanned by CT,and the CT values of the implants were measured and comparatively analyzed.Subsequently,the implants were harvested and stained with hematoxylin and eosin and Masson trichrome,and the percentages of bone area,scaffold area,and collagen area were calculated and compared between the two groups.Results The imaging results showed that the densities of implants of the two groups gradually increased along with time,but the CT values of implants in the CS＋cells group were much higher than in the CS group at the same time point （P ＜0.05）.The histological results showed that the de novo bone and collagen formed in the pores of the scaffolds and gradually increased since 2 weeks postoperation in both groups,and the scaffold gradually degraded along with the boneforming process.However,the comparative analysis results showed that the CS＋cells group gained more de novo bone and collagen formation and had less scaffold than the CS group at the same time point （P ＜0.05）.Conclusion The CS/osteo-induced BMSC composites are excellent bone tissue engineering substitutes,and the scaffold biodegradation is accordant with the bone formation.

Biological Properties of Chitosan Films with Different Degree of Deacetylation

Chitin and chitosan films were prepared by solution casting method. Chitosan specimens used in this study were deacetylated by 50.4%, 69.2%, 85.5% and 96.3%. Their water content, protein adhesion ability, cytocompatibility, cell adhesion ability, in vitro and vivo degradability and biocompatibility were evaluated. Results indicated that with the degree of deacetylation （DD） between 50% and 70%, the chitosan showed higher water content. The higher the DD, the stronger protein adhesion ability the chitosan had. All the films have good cytocompatibility and the films with higher DD have better cell adhesion ability. Chitin films degraded more rapidly than others, which disappeared in 2 to 4 weeks after they were implanted in subcutaneous tissue and musculature. Their inflammatory reaction became weaker as the films degraded. As the DD got higher, the films degraded slower. The films of DD 85.5% and DD 90.3% even didn＇t disappeared in 12 weeks after they were implanted. Their inflammatory reaction was mild at the beginning of degradation, and became severe in 4 to 8 weeks, then weaken at last. This basic result can be very helpful for tissue engineering.

Biodegradable Colour Polymeric Film (Starch-Chitosan) Development: Characterization for Packaging Materials

Biodegradable starch-based chitosan reinforced composite polymeric films were prepared by casting. The chitosan content in the films was varied from 20% to 80% (w/w). Tensile strength (TS) was improved significantly with the addition of chitosan but elongation at break (EB %) of the composites decreased. Tensile strength of the composites raised more with the addition of the acacia catechu content in the films varied from 0.05% to 0.2% (w/w). The better thermal stability of this prepared film was confirmed by thermo-gravimetric analysis. Structural characterization was done by Fourier transform infrared spectroscopy. Surface morphologies of the composites were examined by scanning electron microscope (SEM) which suggested sufficient homogenization of starch, chitosan and acacia catechu. Water uptake was found lower for final composites in comparison to starch/chitosan and chitosan films. The satisfactory rate of degradation in the soil is expected that the final composite film is within less than 6 months. The developed films intended to use as the alternative of synthetic non-biodegradable colored packaging films.

Bombyx Mori Chitosan Nanoparticles: Synthesis and Properties

A synthesis of nanochitosan from Bombyx mori chitosan with particle sizes of 20 - 100 nm was carried out. The antibacterial and immunological properties of synthesized nanochitosan were first studied. It was revealed that preparations based on nanochitosan have pronounced antibacterial activity, and are also able to significantly increase the immune response of the living system.

Synthesis and Characterization of New Biodegradable Chitosan/Polyvinyl Alcohol/Cellulose Nanocomposite

In this report, a new nanocomposite based on chitosan/polyvinyl alcohol/nanocrystalline cellulose (Cts/PVA/NCC) was synthesized. The morphology and particle size of NCC and nanocomposites were studied by scanning electron microscopy (SEM), X-ray diffraction (XRD) analysis and Fourier transform infrared (FT-IR) spectroscopy. According to XRD results, the size of NCC was found to be at the range of 15 - 17 nm. SEM images showed the rod-like shape of NCC whiskers. Finally, biodegradation and swelling studies were performed on Cts/PVA/NCC nanocomposites.

Development of Ecological Absorbent Core Sanitary Pads in Combination of Kenaf and Chitosan Fibers

The menstrual cycle is always considered as a big nightmare by many women. This research aims to make this process smooth and safe by developing natural sanitary pads which are used to absorb and retain menstrual blood from the body. Some existing sanitary pads contain 90% plastics made of non-woven polypropylene/polyethylene sheets, super absorbent polymers, and polyethylene back sheets that will take up to 600 - 800 years to decompose. So, biodegradable sanitary pads using natural fibers are the best alternative to eliminate the pads which contain non-biodegradable materials. In this research, nonwoven bamboo will be used as the top layer, nonwoven cotton will be used as the second layer, the absorbent core is to be made by the combination of kenaf and chitosan fibers as the third layer, cotton as the fourth layer, and cornstarch-based bioplastic sheets as the bottom layer. These biodegradable natural materials will change the menstrual process into a healthy one as well as create a robust ecological community.

Chitosan as A Preservative for Fruits and Vegetables:A Review on Chemistry and Antimicrobial Properties

Chitosan,derived from chitin,a major constituent(in quantity)of crustaceans,is a unique aminopolysaccharide with emerging commercial potential in agriculture,food,pharmaceuticals and nutraceuticals due to its nontoxic,biodegradable and biocompatable properties.Chitosan coating on fruits and vegetables has been found to be effective for the reduction of a variety of harmful micro-organims and extend the shelf-life of these products.In this review,our focus is on the antimicrobial properties of chitosan and its application as a natural preservative for fresh products.We detailed the key properties that are related to food preservation,the molecular mechanism of the antimicrobial activity of chitosan on fungi,gram-positive and gram-negative bacteria,coating methods for using chitosan and its formulation for preserving fruits and vegetables,as well as the radiation method of producing chitosan from chitin.Understanding the economic and scientific factors of chitosan’s production and efficiency as a preservative will open its practical application for fruits and vegetable preservation.

Chitosan Conduit for Peripheral Nerve Regeneration

Chitosan, the N\|deacetylated form of chitin, has good biocompatibility and biodegradability. This paper investigates the feasibility of using chitosan conduits for peripheral nerve regeneration. Cell culture experiments were used to test the material's cytotoxicity and affinity to nerve cells. Conduit implantation experiments were used to study the degradation of the material and the regeneration of injured sciatic nerves. The primary results indicate that chitosan has good mechanical properties, biocompatibility, and biodegradability and it may be a promising biomaterial for peripheral nerve regeneration.

Development of Ficus carica Linn leaves extract incorporated chitosan films for active food packaging materials and investigation of their properties

The serious problems caused by extensive usage of petroleum-based plastic materials led to investigating the comprehensive studies and developing active food packaging materials.Even if the chitosan-based films are considered an attractive source,they exhibit some practical difficulties in developing active food packaging applications.Hence,Ficus carica Linn leaves extract(FLE),with the features of its cheapness,easy accessibility and superoxide anion radical scavenging activity,was incorporated into chitosan(CS)film at various concentrations(2%-6%w/w).To the best of our knowledge,this was the first time that FLE was utilized as a bioactive substance incorporated into chitosan films to develop eco-friendly,biodegradable,active food packaging material.The results obtained revealed that FLE incorporation into chitosan films significantly improved the swelling,water solubility and opacity of neat chitosan films.FTIR and morphological analysis indicated that the films produced exhibited smooth structure with homogenous dispersion of FLE.In mechanically,the addition of FLE resulted in a significant reduction in tensile strength while the elasticity of the films was improved.Additionally,the antioxidant and biodegradability properties of neat chitosan films were enhanced significantly.It was concluded that CS-FLE films appeared to be a capable and enhanced option for synthetic polymer-based food packaging materials.Based on the analyses performed,further studies are suggested on the packaging application for various foods and to evaluate the possible interaction of packaging film materials with the compounds of the food products,to avoid possible negative effects.

壳聚糖生物降解薄膜在食品保鲜包装中的应用进展

壳聚糖是天然高分子材料,其来源广,可再生,生物降解性和生物相容性良好,同时也具有优良的成膜性能、抗菌性能和抗氧化性能,在食品保鲜包装领域展现出巨大的应用前景。本文综述了壳聚糖生物降解薄膜的制备方法、改性方法和其在食品保鲜包装中的应用进展,并对壳聚糖生物降解薄膜的未来发展方向进行了展望。今后对壳聚糖食品包装材料的研究,应侧重于降低材料成本,提升材料的安全性;还应加强对新型壳聚糖复合材料的研究,以拓展其应用范围;此外,还应深入研究壳聚糖的保鲜机理和作用方式,从而提升其保鲜效果和适用性。

壳聚糖和壳寡糖的制备及应用

壳聚糖和壳寡糖因其生物相容性、降解性、无毒和多种生物活性等特性,在食品、化妆品、复合材料、废水处理和生物医药等众多领域广泛应用。本文介绍了壳聚糖和壳寡糖的研究历史、制备原料,分析了壳聚糖的制备工艺(包括脱蛋白工艺、脱盐工艺、脱色工艺、脱乙酰工艺)和应用领域以及壳寡糖的制备方法(包括化学降解法、物理降解法、酶降解法)和应用领域,以期为壳聚糖和壳寡糖及其衍生产品的研究利用提供一定的参考。

壳寡糖交联明胶可生物降解薄膜的制备与性能研究

目的:研究壳寡糖改性对明胶基薄膜性能的影响。方法:以废猪皮中提取明胶为基质,以壳寡糖和聚乙烯醇为改性交联剂,制备得到了明胶基薄膜。利用红外光谱、X射线衍射、扫描电子显微镜、分光光度法、拉力试验测试法对其结构和力学性能进行了测定,并测试了明胶基薄膜在抗氧化、抗菌、水稳定性和生物降解方面的性能。结果:交联改性后明胶薄膜的力学性能得到显著提升,断裂应力最高可达37.09 MPa,最大撕裂能为56.71 kJ/m^(2),且浸泡于水中48 h仍能维持良好的物理形态,此外,薄膜还拥有优异透光性(最大可达92.32%),良好抗氧化性(自由基的清除率最高可达75.12%),优异抗菌性和生物降解性(完全降解时间<45 h)。结论:壳寡糖改性一定程度上改善了明胶基薄膜的力学性能和生物降解性能,赋予了薄膜良好抗菌性和抗氧化能力,表明其在食品包装上存在较大潜在应用价值。

低聚壳聚糖的制备及应用研究进展

从壳聚糖降解得到的低聚壳聚糖具有特殊的生理活性而日益受到人们的关注。综述了近年来壳聚糖降解制备低聚壳聚糖的方法,包括化学降解法、酶降解法、物理作用帮助下的降解法以及复合降解法。重点介绍了这些方法的降解机理、影响因素和对产品质量的影响以及低分子质量壳聚糖在化妆品、食品、医药、农业、抗菌等方面的应用。

壳聚糖膜的降解与生物相容性研究

用小鼠作实验动物，研究了壳聚膜的生物降解与生物相容性。结果表明，壳聚糖膜易于生物降解，在植入初期有轻度炎症反应，至１６周后炎症反应基本消失。作为一种新型天然可吸收性生物材料，壳聚糖具有很好的发展应用前景。

壳聚糖钉固定兔胫骨近端截骨的实验研究

用生物相容性较好且可降解吸收的壳聚糖（ｃｈｉｔｏｓａｎ）制成直径４ｍｍ，长３０～４０ｍｍ钉，其抗张强度４３３ＭＰａ，剪切强度４６ＭＰａ。４０只兔胫骨近端做横形截骨，将壳聚糖钉插入髓腔内固定骨折；手术后３、６、１２、２４和４８周作Ｘ线摄片，四环素荧光标记和组织学观察。结果显示：壳聚糖钉植入后３周有骨痂形成，新骨形成和四环素荧光摄入在３～６周最多。除２例壳聚糖钉在术后３周内断裂外，到术后１２周骨折全部愈合。组织学观察术后３～１２周有明显的炎性反应，主要是非特异性的异物排斥反应，这种炎性反应未影响新骨形成和骨折愈后，术后２４周炎性反应减弱。壳聚糖钉在骨内降解缓慢，术后４８周只有表面部分降解，大部分未被正常组织替代。如对壳聚糖钉进行表面改性，增加力学强度，壳聚糖钉有希望用于临床。