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海藻酸盐复合水凝胶是目前肿瘤药物递送系统材料的研究热点之一。海藻酸盐水凝胶具有良好的生物相容性、可再生的特点,然而天然海藻酸盐水凝胶因降解缓慢、凝胶不稳定等缺点使其在机体环境下可能无法实现预期的结果。海藻酸盐通过结合其他材料,并用离子交联、共价交联和自由基聚合等方法形成水凝胶,使其在癌症治疗中得到广泛应用。本文基于海藻酸盐水凝胶复合体系,综述了海藻酸盐水凝胶结构及其基本性质,重点阐述了近几年来海藻酸盐复合水凝胶在常见癌症治疗应用的研究状况,总结当前研究重点方向并讨论了海藻酸盐复合水凝目前存在问题,为进一步拓展海藻酸盐复合水凝胶在临床癌症治疗的研究提供参考。 相似文献
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目的 评价新型静电纺丝伤口敷料的止血性能及促创伤愈合作用,为该敷料的进一步开发应用奠定基础。方法 将胶原蛋白和壳聚糖的混合溶液通过静电纺丝技术纺在海藻酸盐无纺布基布上,制备成新型静电纺丝伤口敷料(胶原蛋白-壳聚糖静电纺丝膜复合海藻酸盐敷料,Collagen-Chitosan Electrostatic spinning membrane Alginate Dressing,CCEAD)。通过体外凝血实验、兔耳动脉创伤止血实验和兔背部创伤止血实验评价CCEAD的止血性能。建立大鼠背部全皮层创伤模型,分别在术后3、5、7、12 d拍照计算伤口愈合率,测定CCEAD的促愈合作用;取伤口创面皮肤组织,HE染色观察组织病理学变化;免疫组化染色观察在伤口愈合过程中CD31、FGF-2和TGF-β的表达情况。结果 CCEAD组的体外凝血指数BCI为36.91±6.62,显著小于阳性对照明胶海绵组(69.82±1.83)和阴性对照医用纱布组(79.93±6.30)(P<0.01)。兔耳动脉创伤止血实验中,CCEAD组的止血时间(107.67±17.62) s短于医用纱布组(163.67±15.50) s(P<0.05)。兔背部创伤止血实验中,CCEAD组Hb光度吸收值(0.120±0.052)明显低于医用纱布组(0.294±0.021)(P<0.01)。在促创伤愈合实验中,术后第7天,CCEAD组愈合率为65.70%±4.94%,高于阳性对照壳聚糖敷料组(48.78%±8.33%,P<0.05),明显高于医用纱布组(37.76%±6.35%,P<0.01)。HE染色显示,CCEAD在伤口愈合早期能够促进成纤维细胞生长和新生血管形成,促进肉芽组织的生成。免疫组化结果显示,CCEAD能促进CD31、FGF-2和TGF-β在伤口愈合早期的表达,有利于伤口的愈合。结论 新型静电纺丝伤口敷料(胶原蛋白-壳聚糖静电纺丝膜复合海藻酸盐敷料)止血性能优良,具有明显的促创伤愈合作用,有望开发成新型伤口敷料。 相似文献
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摘要:目的 研究海藻酸盐敷料的止血性能,并初步探究其生物相容性。方法 采用凝血指数试验测定体外凝血性能。采用新西兰兔耳和背部创伤止血试验测定止血性能。采用溶血试验和细胞毒性试验进行初步安全性评价。结果海藻酸盐敷料、明胶海绵的凝血指数BCI分别为33.1±4.9、72.0±3.3,海藻酸盐敷料凝血效果优于明胶海绵。在背部创伤出血模型中,海藻酸盐敷料、明胶海绵、纱布的平均止血时间为(55.3±5.1)s、(80.2±7.4)s、(101±14.7)s,Hb光度吸收值分别为1.5±0.7、2.5±0.5、3.8±0.7。与明胶海绵比较,海藻酸盐敷料的平均止血时间缩短了31.05%,Hb光度吸收值降低了40.00%;与纱布比较,海藻酸盐敷料的平均止血时间缩短了45.25%,Hb光度吸收值降低了60.53%。在兔耳动脉止血实验中,海藻酸盐敷料、明胶海绵、纱布的出血量分别为(2.4±0.2)g、(3.0±0.2)g、(3.9±0.2)g,止血时间分别为(226.3±6.5)s、(332.3±14.2)s、(466.5±19.1)s。与明胶海绵组比较,海藻酸盐敷料的出血量降低了20.00%,止血时间分别为缩短了31.90%;与纱布比较,海藻酸盐敷料的出血量降低了38.46%,出血时间缩短了51.49%。海藻酸盐敷料的溶血率低于5%。细胞毒性实验中各浓度的海藻酸盐敷料浸提液为0级或1级,提示其对细胞无明显毒性。结论 海藻酸盐敷料具有良好的止血效果,溶血率符合国标要求,且对皮肤成纤维细胞无细胞毒性。 相似文献
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一种新的缓释载体──海藻酸钙凝胶小球的研究概况 总被引:2,自引:0,他引:2
海藻酸及海藻酸盐是来源于褐藻的亲水性胶态多聚糖,是由β-(1,4)-D-甘露糖醛酸(M)和α-(1,4)-L-古罗糖醛酸(G)形成的线性高分子化合物,具有与多价阳离子形成凝胶的特性,如海藻酸钠与钙离子形成海藻酸钙凝胶,电镜扫描为三维网状结构,被称为“鸡蛋箱”结构,非常形象。因此海藻酸及海藻酸盐广泛应用于药学、食品、生物技术领域,作为药物的载体或用于细胞及酶的固定[1,2]。海藻酸钙凝胶小球具有以下特点:(1)溶胀特性,可作为缓控释给药的载体。(2)其溶胀特性受pH值的影响,故可防止酸敏感性药物在胃中被降解。(… 相似文献
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“湿性愈合理论”认为,将创面置于一个封闭、湿润的环境中,有利于创面的加速愈合。封闭敷料(occlusive dressings)是在“湿性愈合理论”指导下研发的新型伤口敷料。其中应用最多的水胶体敷料其基本成分是羧甲基纤维素钠(sodium carboxymethyl cellulose,CMC),具有吸收创面渗液形成凝胶的特性,可以起到保持创面适宜的温湿度、支撑创面的作用。本文对羧甲基纤维素钠在急性伤口中的应用进行简述。 相似文献
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Protein release from alginate matrices 总被引:2,自引:0,他引:2
There are a variety of both natural and synthetic polymeric systems that have been investigated for the controlled release of proteins. Many of the procedures employed to incorporate proteins into a polymeric matrix can be harsh and often cause denaturation of the active agent. Alginate, a naturally occurring biopolymer extracted from brown algae (kelp), has several unique properties that have enabled it to be used as a matrix for the entrapment and/or delivery of a variety of biological agents. Alginate polymers are a family of linear unbranched polysaccharides which contain varying amounts of 1,4'-linked beta-D-mannuronic acid and alpha-L-guluronic acid residues. The residues may vary widely in composition and sequence and are arranged in a pattern of blocks along the chain. Alginate can be ionically crosslinked by the addition of divalent cations in aqueous solution. The relatively mild gelation process has enabled not only proteins, but cells and DNA to be incorporated into alginate matrices with retention of full biological activity. Furthermore, by selection of the type of alginate and coating agent, the pore size, degradation rate, and ultimately release kinetics can be controlled. Gels of different morphologies can be prepared including large block matrices, large beads (>1 mm in diameter) and microbeads (<0.2 mm in diameter). In situ gelling systems have also been made by the application of alginate to the cornea, or on the surfaces of wounds. Alginate is a bioadhesive polymer which can be advantageous for the site specific delivery to mucosal tissues. All of these properties, in addition to the nonimmunogenicity of alginate, have led to an increased use of this polymer as a protein delivery system. This review will discuss the chemistry of alginate, its gelation mechanisms, and the physical properties of alginate gels. Emphasis will be placed on applications in which biomolecules have been incorporated into and released from alginate systems. 相似文献
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There are a variety of both natural and synthetic polymeric systems that have been investigated for the controlled release of proteins. Many of the procedures employed to incorporate proteins into a polymeric matrix can be harsh and often cause denaturation of the active agent. Alginate, a naturally occurring biopolymer extracted from brown algae (kelp), has several unique properties that have enabled it to be used as a matrix for the entrapment and/or delivery of a variety of biological agents. Alginate polymers are a family of linear unbranched polysaccharides which contain varying amounts of 1,4′-linked β-d-mannuronic acid and α-l-guluronic acid residues. The residues may vary widely in composition and sequence and are arranged in a pattern of blocks along the chain. Alginate can be ionically crosslinked by the addition of divalent cations in aqueous solution. The relatively mild gelation process has enabled not only proteins, but cells and DNA to be incorporated into alginate matrices with retention of full biological activity. Furthermore, by selection of the type of alginate and coating agent, the pore size, degradation rate, and ultimately release kinetics can be controlled. Gels of different morphologies can be prepared including large block matrices, large beads (> 1 mm in diameter) and microbeads (< 0.2 mm in diameter). In situ gelling systems have also been made by the application of alginate to the cornea, or on the surfaces of wounds. Alginate is a bioadhesive polymer which can be advantageous for the site specific delivery to mucosal tissues. All of these properties, in addition to the nonimmunogenicity of alginate, have led to an increased use of this polymer as a protein delivery system. This review will discuss the chemistry of alginate, its gelation mechanisms, and the physical properties of alginate gels. Emphasis will be placed on applications in which biomolecules have been incorporated into and released from alginate systems. 相似文献
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The aims of this research were to develop a novel bilayer hydrocolloid film based on alginate and to investigate its potential as slow-release wound healing vehicle. The bilayer is composed of an upper layer impregnated with model drug (ibuprofen) and a drug-free lower layer, which acted as a rate-controlling membrane. The thickness uniformity, solvent loss, moisture vapour transmission rate (MVTR), hydration rate, morphology, rheology, mechanical properties, in vitro drug release and in vivo wound healing profiles were investigated. A smooth bilayer film with two homogenous distinct layers was produced. The characterisation results showed that bilayer has superior mechanical and rheological properties than the single layer films. The bilayers also showed low MVTR, slower hydration rate and lower drug flux in vitro compared to single layer inferring that bilayer may be useful for treating low suppurating wounds and suitable for slow release application on wound surfaces. The bilayers also provided a significant higher healing rate in vivo, with well-formed epidermis with faster granulation tissue formation when compared to the controls. In conclusions, a novel alginate-based bilayer hydrocolloid film was developed and results suggested that they can be exploited as slow-release wound dressings. 相似文献
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Electrospinning of polysaccharides for regenerative medicine 总被引:1,自引:0,他引:1
Electrospinning techniques enable the production of continuous fibers with dimensions on the scale of nanometers from a wide range of natural and synthetic polymers. The number of recent studies regarding electrospun polysaccharides and their derivatives, which are potentially useful for regenerative medicine, is increasing dramatically. However, difficulties regarding the processibility of the polysaccharides (e.g., poor solubility and high surface tension) have limited their application. In this review, we summarize the characteristics of various polysaccharides such as alginate, cellulose, chitin, chitosan, hyaluronic acid, starch, dextran, and heparin, which are either currently being used or have potential to be used for electrospinning. The recent progress of nanofiber matrices electrospun from polysaccharides and their biomedical applications in tissue engineering, wound dressings, drug delivery, and enzyme immobilization are discussed. 相似文献
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Recombinant human basic-fibroblastic growth factor: different medical dressings for clinical application in wound healing. 总被引:2,自引:0,他引:2
Recombinant human basic-Fibroblastic Growth Factor (rhb-FGF) is a basic single-chain protein showing high activity as mitogenetic and angiogenetic agent. The application of rhb-FGF in wound healing as stimulator of the tissue repair process is strictly connected with the covering of the wound by means of a proper dressing. A wide number of synthetic occlusive or non-occlusive wound dressings has been developed. Owing to the delicate proteic structure of rhb-FGF, and generally of all the Growth Factors, compatibility with the dressings has to be every time tested, to avoid its inactivation and consequent loss of tissue repair properties. 相似文献
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Silvia Rossi Marzia Marciello Giuseppina Sandri Franca Ferrari Maria Cristina Bonferoni Adele Papetti 《Pharmaceutical development and technology》2013,18(4):415-422
In the present work wound dressings, based on chitosan hydrochloride (HCS), 5-methyl-pyrrolidinone chitosan (MPC), and their mixtures with an anionic polymer, hyaluronic acid (HA), were prepared by freeze-drying. Chlorhexidine diacetate (CX) was used as an antimicrobic drug. The mechanical properties of the wound dressings were investigated. In particular, the wound dressings were subjected to dynamic hydration measurements to evaluate their capability to absorb wound exudate and to rheological analysis to investigate their resistance to mechanical stresses on hydration. The wound dressings were also characterized for drug release properties. The antioxidant and antimicrobial activities of medicated and non-medicated wound dressings were also investigated. All the wound dressings are characterized by mechanical resistance suitable for skin application. The addition of hyaluronic acid to chitosans leads to a reduction in wound dressing hydration properties and a modulation of drug release. The wound dressing based on MPC is characterized by the highest elastic properties and by the best scavenger activity. Antimicrobial activity against bacteria and C. albicans is shown by the dressing based on chitosan also in absence of chlorhexidine. 相似文献
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Wound dressings based on chitosans and hyaluronic acid for the release of chlorhexidine diacetate in skin ulcer therapy 总被引:2,自引:0,他引:2
Rossi S Marciello M Sandri G Ferrari F Bonferoni MC Papetti A Caramella C Dacarro C Grisoli P 《Pharmaceutical development and technology》2007,12(4):415-422
In the present work wound dressings, based on chitosan hydrochloride (HCS), 5-methyl-pyrrolidinone chitosan (MPC), and their mixtures with an anionic polymer, hyaluronic acid (HA), were prepared by freeze-drying. Chlorhexidine diacetate (CX) was used as an antimicrobic drug. The mechanical properties of the wound dressings were investigated. In particular, the wound dressings were subjected to dynamic hydration measurements to evaluate their capability to absorb wound exudate and to rheological analysis to investigate their resistance to mechanical stresses on hydration. The wound dressings were also characterized for drug release properties. The antioxidant and antimicrobial activities of medicated and non-medicated wound dressings were also investigated. All the wound dressings are characterized by mechanical resistance suitable for skin application. The addition of hyaluronic acid to chitosans leads to a reduction in wound dressing hydration properties and a modulation of drug release. The wound dressing based on MPC is characterized by the highest elastic properties and by the best scavenger activity. Antimicrobial activity against bacteria and C. albicans is shown by the dressing based on chitosan also in absence of chlorhexidine. 相似文献