Water absorbing and antibacterial properties of N-isopropyl acrylamide grafted and collagen/chitosan immobilized polypropylene nonwoven fabric and its application on wound healing enhancement

A durable sandwich wound dressing system with high liquid absorbing, biocompatibility, and antibacterial properties was designed. Various solution weight ratios of collagen to chitosan were used to immobilize on the polypropylene nonwoven fabric, which were pregrafted with acrylic acid (AA) or N-isopropyl acrylamide (NIPAAm) to construct a durable sandwich wound dressing membrane with high water absorbing, easy removal, and antibacterial activity. Swelling properties and antibacterial activity of the membranes were measured, and wound healing enhancement by skin full-thickness excision on animal model was examined. The results indicated that NIPAAm-grafted and collagen/chitosan-immobilized polypropylene nonwoven fabric (PP-NIPAAm-collagen-chitosan) showed a better healing effect than AA-grafted and collagen/chitosan-immobilized polypropylene nonwoven fabric (PP-AA-collagen-chitosan). The wound treated with PP-NIPAAm-collagen-chitosan demonstrated the excellent remodeling effect in histological examination with respect to the construction of vein, epidermis, and dermis at 21 days after skin injury. The values of water uptake and water diffusion coefficient for PP-NIPAAm-collagen-chitosan were higher than that for PP-AA-collagen-chitosan under a given solution weight ratio of collagen/chitosan. Both PP-NIPAAm-collagen-chitosan and PP-AA-collagen-chitosan demonstrated antibacterial activity.     

Enhanced biocompatibility and antibacterial property of polyurethane materials modified with citric acid and chitosan

Citric acid (CA) and chitosan (CS) were covalently immobilized on polyurethane (PU) materials to improve the biocompatibility and antibacterial property. The polyurethane pre-polymer with isocyanate group was synthesized by one pot method, and then grafted with citric acid, followed by blending with polyethersulfone (PES) to prepare the blend membrane by phase-inversion method so that chitosan can be grafted from the membrane via esterification and acylation reactions eventually. The native and modified membranes were characterized by attenuated total reflectance-Fourier transform infrared spectroscope, X-ray photoelectron spectroscopy, scanning electron microscopy, water contact angle measurement, and tensile strength test. Protein adsorption, platelet adhesion, hemolysis assay, activated partial thromboplastin time, prothrombin time, thrombin time, and adsorption of Ca²⁺ were executed to evaluate the blood compatibility of the membranes decorated by CA and CS. Particularly, the antibacterial activities on the modified membranes were evaluated based on a vitro antibacterial test. It could be concluded that the modified membrane had good anticoagulant property and antibacterial property.     

Nonwoven supported temperature-sensitive poly(N-isopropylacrylamide)/polyurethane copolymer hydrogel with antibacterial activity

This article is focused on the study of the antibacterial activity of temperature sensitive poly(N-isopropylacrylamide/polyurethane (PNIPAAm/PU) hydrogel grafted nonwoven fabrics with chitosan modification. A series of temperature sensitive hydrogel grafted nonwoven fabrics with different N-isopropylacrylamide/polyurethane (NIPAAm/PU) feeding ratios have been synthesized by using ammonium persulfate (APS) as initiator and N,N,N',N'-tetramethyl-ethane-1,2-diamine (TEMED) as accelerator. FTIR and XPS were used to examine the surface modification of chitosan. The phase transition temperature of hydrogel grafted nonwoven fabrics was about 32 degrees C by DSC. S. aureus and E. coli were used to evaluate the antibacterial efficiency of the fabric composite. After chitosan modification, the hydrogel grafted nonwoven cellulose fabrics demonstrates an antibacterial activity to S. aureus. and E. coli and the antibacterial efficiency is about 80%.     

Synthesis and evaluation of collagen-chitosan-hydroxyapatite nanocomposites for bone grafting

Incorporation of hydroxyapatite (HA) into the matrix of collagen (Col) and chitosan (Chi) by in situ synthesis was introduced to prepare nanocomposites. Structural investigations of the pure Col-Chi mixture validated the influence of Chi on Col assembly, but the molecular interactions between Col and Chi was partially depressed during the intervention of in situ HA synthesis, as revealed by FTIR and DSC analyses. A series of Col-Chi-HA (CCHA) nanocomposites with varying HA content were thereby prepared by a sequential method, involving in situ synthesis in the Col-Chi system, then gelling at 25 degrees C and subsequently washing the resultant elastic gel followed by dehydration consolidation. The structural characteristics and biological properties of the dehydrated CCHA nanocomposites were further evaluated by using XRD, FTIR, TG, and SEM analyses and the osteoblast culture experiment. Formation of a well integrated microstructure of organic fibers (ca. 90 nm in size) and dense matrix including inorganic aggregates (less than 30 nm in size) was found in these nanocomposites. Rat Ros 17/2.8 Osteoblasts proliferated and attached well on the surface of both CCHA nanocomposite and Col-Chi mixture. These results indicated that in situ HA synthesis in the Col-Chi system provided a feasible route for bone grafting nanocomposites.     

Wound healing properties of PVA/starch/chitosan hydrogel membranes with nano Zinc oxide as antibacterial wound dressing material

In this work, hydrogel membranes were developed based on poly vinyl alcohol (PVA), starch (St), and chitosan (Cs) hydrogels with nano Zinc oxide (nZnO). PVA/St/Cs/nZnO hydrogel membranes were prepared by freezing-thawing cycles, and the aqueous PVA/St solutions were prepared by dissolving PVA in distilled water. After the dissolution of PVA, starch was mixed, and the mixture was stirred. Then, chitosan powder was added into acetic acid, and the mixture was stirred to form a chitosan solution. Subsequently, Cs, St and PVA solutions were blended together to form a homogeneous PVA/St/Cs ternary blend solution. Measurement of Equilibrium Swelling Ratio (ESR), Water Vapor Transmission Test (WVTR), mechanical properties, scanning electron microscopy (SEM), MTT [3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyl tetrazolium bromide] assay, antibacterial studies, in vivo wound healing effect and histopathology of the hydrogel membranes were then performed. The examination revealed that the hydrogel membranes were more effective as a wound dressing in the early stages of wound healing and that the gel could be used in topic applications requiring a large spectrum of antibacterial activity; namely, as a bandage for wound dressing.     

Protein adsorption,fibroblast activity and antibacterial properties of poly(3-hydroxybutyric acid-co-3-hydroxyvaleric acid) grafted with chitosan and chitooligosaccharide after immobilized with hyaluronic acid

Poly(3-hydroxybutyric acid-co-3-hydroxyvaleric acid) (PHBV) membrane was treated with ozone and grafted with acrylic acid. The resulting membranes were further grafted with chitosan (CS) or chitooligosaccharide (COS) via esterification. Afterward hyaluronic acid (HA) was immobilized onto CS- or COS-grafting membranes. The antibacterial activity of CS and COS against Staphylococus aureus, Escherichia coli, and Pseudomonas aeruginosa was preserved after HA immobilization. Among them, CS-grafted PHBV membrane showed higher antibacterial activity than COS-grafted PHBV membrane. In addition, after CS- or COS-grafting, the L929 fibroblasts attachment and protein adsorption were improved, while the cell number was decrease. After immobilizing HA, the cell proliferation was promoted, the protein adsorption was decreased, and the cell attachment was slightly lower than CS- or COS-grafting PHBV.     

Biological and antibacterial properties of plasma sprayed wollastonite coatings grafting gentamicin loaded collagen

In this work, gentamicin loaded collagen was grafted on the surface of plasma sprayed wollastonite coatings to obtain an implant having excellent bioactivity and cytocompatibility as well as antibacterial property. The bioactivity and cytocompatibility of the wollastonite coatings grafting gentamicin loaded collagen were examined by simulated body fluid (SBF) soaking test and in vitro cell culture test. The release rate of gentamicin from collagen was measured using UV spectrophotometer in phosphate-buffered saline (PBS) and the antibacterial activity against Staphylococcus aureus (S. aureus) was evaluated by zone of inhibition test and bacterial counting method. The results showed that a composite layer with collagen and silicon-rich particles was formed on the surface of the coating after the graft of collagen. The grafted collagen layer mixed with silicon-rich particles could induce the precipitation of apatite after soaking in SBF for 14 days and improved the cellular proliferation on wollastonite coatings. The release of gentamicin from the collagen layer sustained 11 days in PBS and effectively inhibited the growth of S. aureus. In conclusion, the wollastonite coating grafting gentamicin loaded collagen had excellent bioactivity and cytocompatibility as well as good antibacterial properties, which would be beneficial for the long term stability and surgical success rate of implants.     

胶原/壳聚糖止血敷料在外科伤口中的应用

背景：壳聚糖与胶原联合可更有效地止血。 目的：评价胶原/壳聚糖止血敷料的材料学性能及应用于外科伤口的生物相容性。 方法：以“生物材料,止血敷料,纱布,胶原/壳聚糖,生物相容性”为中文关键词,以“biomaterial;hemostatic material;bioresorbable material;hemostasis effect;hemostatic mechanism”为英文关键词,采用计算机检索2000-01/2010-06与生物敷料、胶原/壳聚糖止血材料在伤口或创面止血过程中应用相关的文献。 结果与结论：壳聚糖独特的生物学特性,具有广谱抑菌、促进上皮细胞生长及止血,促进创面愈合的作用,在体内具有良好的生物降解性与组织相容性,可用于指端损伤和肉芽创面的治疗,如制成伤口敷料、可吸收缝线、止血材料、防粘连剂、药物缓释及组织工程支架,用于平战时伤口的处理。     

含纳米银壳聚糖/聚乙烯醇抗菌敷料的制备和性能

背景：抗菌敷料是预防创面发生侵袭性感染的重要措施之一,但长期使用抗生素会使细菌产生耐药性;同时,将抗菌材料与棉织物复合制得的抗菌敷料,生物相容性差,不宜用于创面的长期覆盖。 目的：制备一种具有良好的生物相容性、抗菌消炎性的新型抗菌生物敷料,并初步检测该材料的生物学性能。 方法：通过在乙醇/水/NaOH溶液中,构建一个纳米级的吸附相反应器,制得吸附纳米银的纳米SiO₂粉末;将载银的SiO₂粉末添加到壳聚糖/聚乙烯醇反应溶液中,通过缩醛化反应制得含Ag/SiO₂纳米颗粒的壳聚糖/聚乙烯醇海绵。检测材料的各项物理性能、表面形貌、细胞毒性、抗菌性能。 结果与结论：材料呈多孔结构,吸水率、透气性和保湿性良好,具有较高的拉伸强度;材料孔隙率高、空隙致密均匀,孔径大小为0.1~1 mm;MTT法检测材料对小鼠成纤维细胞毒性显示无明显毒性,并且能促进该细胞的生长;材料对金黄色葡萄球菌、大肠杆菌、白色念珠菌、铜绿假单胞菌、伤寒沙门菌均有良好的杀菌效果。以上结果显示材料不但具有良好的物理性能、生物活性和抗菌性能,而且合成工艺简单,可作为创面敷料。     

葡甘聚糖一胶原蛋白一壳聚糖共混膜（I）

用溶液共混法制备了葡甘聚糖一胶原蛋白一壳聚糖（KCCS）共混膜。并用FT—IR，X—RD，SEM及透光率表征了膜的结构，同时测试了膜的抗张强度、断裂伸长率、吸水率、透水汽性、渗透性和吸附性。结果表明：共混膜中葡甘聚糖、胶原蛋白及壳聚糖之间存在着强烈的相互作用和良好的相容性，三者共混明显改善了纯聚合物和二元膜的性能。以共混膜为载体培养内皮细胞，发现共混膜具有良好的细胞相容性，预示着共混膜可作为潜在的组织工程支架材料。     

含银介孔二氧化硅-壳聚糖复合材料的制备与性能研究

目的探讨含银介孔二氧化硅-壳聚糖复合材料(Ag/MSN-Chi)的制备方法及其微观表征、细胞毒性、吸水性能、抗菌性能及止血性能。 方法以正硅酸乙酯为前驱体，十六烷基三甲基溴化铵为致孔剂，采用离子交换法在介孔二氧化硅纳米粒子(MSN)中引入银离子，制备出具有抗菌作用的新型有序的含银介孔二氧化硅纳米粒子(Ag/MSN)材料。再利用烷基化壳聚糖负载Ag/MSN，制备出Ag/MSN-Chi。根据所用材料不同将实验分为实验组和空白对照组，实验组又分为3个亚组：MSN组、Ag/MSN组、Ag/MSN-Chi组，空白组为不加任何材料的阳性对照。计算MSN和Ag/MSN的比表面积、孔容、孔径和Ag/MSN与Ag/MSN-Chi的电荷。并通过吸水实验、体外凝血实验、抗菌实验对MSN、Ag/MSN和Ag/MSN-Chi的细胞毒性、吸水性能、止血性能及抗菌性能进行评价，计算细胞相对存活率、吸水率、凝血酶原时间(PT)、凝血活酶时间(APTT)及抑菌率。取健康成年新西兰大白兔18只，随机分成3组：对照组(采用医用纱布处理)、Ag/MSN组(采用Ag/MSN处理)、Ag/MSN-Chi组(采用Ag/MSN-Chi处理)，每组6只，建立肝创伤出血模型，计算止血时间。数据比较采用方差分析和t检验。 结果MSN的比表面积为(523.8±12.4) m²/g、孔容为(1.2±0.4) m³/g、孔径为(3.5±0.9) nm；Ag/MSN的比表面积为(521.6±11.7) m²/g、孔容为(1.15±0.5) m³/g、孔径为(3.6±0.7) nm，2种材料的比表面积、孔容、孔径比较差异均无统计学意义(t＝0.224、0.135、0.015，P值均大于0.05)。经测量，Ag/MSN的Zeta电位为－19.7 mV，Ag/MSN-Chi的Zeta电位为10.27 mV，表明Ag/MSN表面电荷从负值变为正值。Ag/MSN-Chi组、Ag/MSN组和MSN组与小鼠成肌细胞共培养1、4、7 d的细胞相对存活率比较，差异均无统计学意义(F＝2.61、4.72、3.52, P值均大于0.05)。Ag/MSN组吸水率分别与MSN组和Ag/MSN-Chi组比较，差异均无统计学意义(t＝0.482、1.159，P值均大于0.05)。经检测，Ag/MSN-Chi组、Ag/MSN组、MSN组和空白对照组的PT比较，差异无统计学意义(F＝10.28，P>0.05)；Ag/MSN-Chi组、Ag/MSN组、MSN组和空白对照组APTT分别为(20.9±2.1)、(28.5±3.4)、(31.4±2.6)、(38.7±2.5) s，4组比较差异有统计学意义(F＝8.70，P<0.05)；Ag/MSN-Chi组、Ag/MSN组、MSN组APTT分别与空白对照组比较，差异均有统计学意义(t＝9.443、4.186、3.506，P值均小于0.05)；Ag/MSN-Chi组APTT与Ag/MSN组比较，差异有统计学意义(t＝3.294，P<0.05)。MSN组在培养0.5、2、4、6、24 h 5个时间点抑菌率比较差异无统计学意义(F＝5.437，P>0.05)；培养0.5 h，Ag/MSN组和Ag/MSN-Chi组抑菌率分别为(99.7±5.2)%、(97.1±5.4)%，与培养0.5 h MSN组抑菌率(11.2±5.8)%比较，差异均有统计学意义(t＝19.678、18.775, P值均小于0.05)；培养24 h，Ag/MSN组和Ag/MSN-Chi组抑菌率分别为(73.2±5.1)%和(72.9±6.9)%，与MSN组(11.8±5.7)%比较，差异均有统计学意义(t＝13.904、11.825, P值均小于0.05)。Ag/MSN-Chi组、Ag/MSN组和对照组止血时间分别为(12.3±1.5)、(17.2±3.4)、(28.1±3.8) s，3组比较差异有统计学意义(F＝5.892，P<0.05)；Ag/MSN-Chi组和Ag/MSN组止血时间分别与对照组比较，差异均有统计学意义(t＝9.473、5.236, P值均小于0.05)；且Ag/MSN-Chi组与Ag/MSN组止血时间比较，差异有统计学意义(t＝3.230，P<0.05)。 结论Ag/MSN-Chi在不增加细胞毒性的基础上具有有较好的吸水性能、止血性能及抗菌性能。     

Electrospun collagen–chitosan nanofiber: A biomimetic extracellular matrix for endothelial cell and smooth muscle cell

Electrospinning of collagen and chitosan blend solutions in a 1,1,1,3,3,3-hexafluoroisopropanol/trifluoroacetic acid (v/v, 90/10) mixture was investigated for the fabrication of a biocompatible and biomimetic nanostructure scaffold in tissue engineering. The morphology of the electrospun collagen–chitosan nanofibers was observed by scanning electron microscopy (SEM) and stabilized by glutaraldehyde (GTA) vapor via crosslinking. Fourier transform infrared spectra analysis showed that the collagen–chitosan nanofibers do not change significantly, except for enhanced stability after crosslinking by GTA vapor. X-ray diffraction analysis implied that both collagen and chitosan molecular chains could not be crystallized in the course of electrospinning and crosslinking, and gave an amorphous structure in the nanofibers. The thermal behavior and mechanical properties of electrospun collagen–chitosan fibers were also studied by differential scanning calorimetry and tensile testing, respectively. To assay the biocompatibility of electrospun fibers, cellular behavior on the nanofibrous scaffolds was also investigated by SEM and methylthiazol tetrazolium testing. The results show that both endothelial cells and smooth muscle cells proliferate well on or within the nanofiber. The results indicate that a collagen–chitosan nanofiber matrix may be a better candidate for tissue engineering in biomedical applications such as scaffolds.     

葡甘聚糖-胶原蛋白-壳聚糖共混膜(I)

用溶液共混法制备了葡甘聚糖-胶原蛋白-壳聚糖(KCCS)共混膜。并用FT-IR,X-RD,SEM及透光率表征了膜的结构,同时测试了膜的抗张强度、断裂伸长率、吸水率、透水汽性、渗透性和吸附性。结果表明:共混膜中葡甘聚糖、胶原蛋白及壳聚糖之间存在着强烈的相互作用和良好的相容性,三者共混明显改善了纯聚合物和二元膜的性能。以共混膜为载体培养内皮细胞,发现共混膜具有良好的细胞相容性,预示着共混膜可作为潜在的组织工程支架材料。     

羧甲基壳聚糖用作防止术后粘连的研究

本研究合成制备了N-羧甲基壳聚糖（N-CMC）、O-羧甲基壳聚糖（O-CMC）和N,O-羧甲基壳聚糖（N,O-CMC）;研究了它们的凝血性、体外酶解、抑菌性、对细胞生长的影响、对胶原合成的作用等生物特性;评价了它们的动物体内防粘连效果.研究结果表明,与N-CMC和N,O-CMC相比,O-CMC具有良好的凝血性,良好的生物降解性,轻微的抑菌活性,适度的抑制成纤维细胞增殖作用,轻微的抑制表皮细胞增殖作用,能抑制成纤维细胞胶原合成的能力,显示较好的防止术后粘连的效果,有希望成为新一代术后防止粘连材料.     

京尼平交联3D打印胶原/壳聚糖支架的表征北大核心

背景:胶原/壳聚糖支架需交联才能达到相应力学性能,有研究表示调节交联剂浓度可以在一定范围内调控支架的理化性能。目的:探究京尼平浓度对胶原/壳聚糖支架理化性能的影响,制备理化性能可调节的组织工程支架。方法:将胶原和壳聚糖粉末分别溶于弱酸后混合均匀,作为打印墨水,利用生物3D打印机低温打印胶原支架与胶原/壳聚糖支架,经冻干、中和处理后分别以1,3,5 mmol/L的京尼平进行交联。检测各组支架的表观结构稳定性、抗拉能力、溶胀性能、降解性能与生物相容性。结果与结论:①将支架在PBS中浸泡3 d后,对比未交联的冻干支架,交联后胶原支架表面维持规则的孔结构,但是支架出现明显变形;交联后胶原/壳聚糖支架表面结构规则,仅1 mmol/L京尼平交联的胶原/壳聚糖支架存在轻微变形。②随着京尼平浓度的增加,各组支架的力学性能增加,并且对应交联浓度下的胶原/壳聚糖支架力学性能好于胶原支架。③随着京尼平浓度的增加,胶原支架的溶胀率下降,胶原/壳聚糖支架的溶胀率无明显变化。④浸泡于胶原酶溶液中后,不同浓度京尼平交联的胶原支架在1 h内被完全降解,胶原/壳聚糖支架的降解速率随京尼平浓度的增加而降低,均呈现先快速后平缓的趋势。⑤将骨髓间充质干细胞接种于各组交联支架3 d后,1,3 mmol/L京尼平交联的胶原/壳聚糖支架(或胶原支架)上的细胞数量明显多于5 mmol/L京尼平交联的胶原/壳聚糖支架(P<0.05)。⑥结果表明,京尼平可在一定范围调节胶原/壳聚糖支架理化性能,其中3 mmol/L京尼平交联的胶原/壳聚糖支架具有较好的力学性能、抗酶解能力与生物相容性。     

Preparation of a novel antibacterial chitosan-poly(ethylene glycol) cryogel/silver nanoparticles composites

Cryogel was synthesized through cryogelation of methacrylated carboxymethyl chitosan (mCMC) and poly(ethylene glycol) diacrylate (PEGDA) precursors by photopolymerization. Due to its excellent properties, such as fast swelling behavior, inter-connective porous structure, high water absorbing capacity, especially the presence of abundant carboxylmethyl groups on its backbone, the cryogel not only favored the absorption of silver ions but also was proved to be a good matrix for the incorporation of silver nanoparticles (AgNPs) by in situ chemical reduction. The structure, morphology, and swelling behavior of the cryogel and cryogel/AgNPs composite were characterized. And the results of inhibition zone test and antibacterial inhibition ratio indicated the cryogel/AgNPs composite exhibited prominent and durable antibacterial activity against Gram-negative E. coli and could be utilized as potential antibacterial materials.     

胶原-壳聚糖复合材料作为组织工程支架的研究

目的 本研究考察壳聚糖对于胶原膜理化性质的影响,选择合适比例的胶原-壳聚糖复合膜作为骨髓间充质干细胞（BMSCs）载体.方法 胶原溶涨液中添加一定比例的壳聚糖,交联并冷冻干燥制备多孔组织工程支架,研究壳聚糖对胶原膜形态学、孔隙率、机械强度、降解特性等理化性质的影响,并初步探讨了胶原-壳聚糖材料作为组织工程三维支架材料与BMSCs的相容性.结果 制备的胶原-壳聚糖支架孔径分布均匀;相对于单纯胶原海绵支架,胶原-壳聚糖复合材料支架降低体外降解速度,提高支架材料的力学性能,稳定支架的结构.BMSCs种植于胶原-壳聚糖（mCol∶mCS=9∶1）支架14 d时,SEM观察到细胞通过微绒毛与支架纤维复合,细胞相容性好.结论 胶原-壳聚糖复合支架有良好的细胞相容性,作为BMSCs诱导体外支架材料具有好的研究前景.     

Organic/inorganic hybrid network structure nanocomposite scaffolds based on grafted chitosan for tissue engineering

We describe the first study of structure-processing-property relationship in organic/inorganic hybrid network structure nanocomposite scaffolds based on grafted chitosan for bone tissue engineering. Chitosan was first grafted with propylene oxide to form hydroxypropylated chitosan, which was subsequently linked with ethylene glycol functionalized nanohydroxyapatite to form an organic/inorganic network structure. The resulting scaffold was characterized by a highly porous structure and significantly superior physico-chemical, mechanical and biological properties compared to pure chitosan. The scaffolds exhibited high modulus, controlled swelling behavior and reduced water uptake, but the water retention ability was similar to pure chitosan scaffold. MTT assay studies confirmed the non-cytotoxic nature of the scaffolds and enabled degradation products to be analyzed. The nanocomposite scaffolds were biocompatible and supported adhesion, spreading, proliferation and viability of osteoblasts cells. Furthermore, the cells were able to infiltrate and colonize into the pores of the scaffolds and establish cell-cell interactions. The study suggests that hydroxypropylation of chitosan and forming a network structure with a nano-inorganic constituent is a promising approach for enhancing physico-chemical, functional and biological properties for utilization in bone tissue engineering applications.     

Covalent immobilization of chitosan derivatives onto polymeric film surfaces with the use of a photosensitive hetero-bifunctional crosslinking reagent

Partially N-acetylated chitosan was covalently immobilized onto polymeric film surfaces using the photosensitive hetero-bifunctional crosslinking reagent, methyl 4-azidobenzoimidate, which was previously attached to the chitosan by the reaction between an imidoester group of the reagent and a free amino group of the chitosan. The grafting was accomplished by irradiating with ultraviolet light the modified chitosan being coated on the film surfaces to photolyse arylazide groups, thus crosslinking the chitosan and the underlying substrate polymer together. For ultraviolet absorption and infrared spectroscopy, the irradiation time of 3 min was found to be sufficient for the photolysis of the azide group. The thickness of the immobilized chitosan layer was estimated to be of the order of 30–150 nm using attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR). The chitosan molecules immobilized on the surfaces could be chemically modified by several reagents and also treated with a heparin solution to form a polyelectrolyte complex on the surface. The ionically bound heparin was partially released into a phosphate buffer solution.     

胶原蛋白/壳聚糖复合纳米纤维膜在生物医学工程中的应用

背景：胶原蛋白-壳聚糖复合纳米纤维膜以其优异的力学性能和良好的组织细胞相容性而成为近年来科学研究的热点。 目的：总结胶原蛋白/壳聚糖复合纳米纤维膜在生物医学工程中的应用进展。 方法：以“胶原蛋白、壳聚糖、复合纳米纤维膜、胶原蛋白/壳聚糖复合纳米纤维膜、collagen/chitosan、compound Nanofiber membrane、collagen/chitosan compound nanofiber membrane、development of research” 为检索词,应用计算机检索Pubmed数据库、Elsevier数据库、万方数据库1993-01/2010-05关于胶原蛋白/壳聚糖复合纳米纤维膜研究的相关文章,对53篇文献进行分析。 结果与结论：研究表明,将胶原蛋白/壳聚糖共混,在不同条件下交联,其共混复合物在力学性能方面较单一的胶原蛋白有一定的改善,其共混膜可以作为较小软骨缺损的修复的支架材料。研究证实胶原蛋白/壳聚糖复合纳米纤维膜有着优异的力学性能、很好的组织细胞相容性和生物可降解性。文章从胶原蛋白和壳聚糖单一生物材料的缺陷性、复合纤维膜的优势及其在生物医药工程中的应用方面进行了探讨。