Effect of nano-hydroxyapatite/collagen composite and bone morphogenetic protein-2 on lumbar intertransverse fusion in rabbits

Objective: To investigate the effect of nano hydroxyapatite/collagen (nHA/collagen) composite as a graft extender and enhancer when combined with recombinant human bone morphogenetic protein 2 (rhBMP 2) on lumbar intertransverse fusion in rabbits. Methods: Sixty four adult female New Zealand white rabbits, aged 1 year and weighing 3.5 4.5 kg, underwent similar posterolateral intertransverse process arthrodesis and were randomly divided into 4 groups based on different grafts: autogenous cancellous bone alone (ACB group), nHA/collagen alone (HAC group), half autogenous cancellous bone and half nHA/collagen (ACB+HAC group) and nHA/collagen combined with rhBMP 2 (HAC+BMP group). The fusion masses were analyzed by manual palpation, radiography, biomechanical testing and histological examination. Results: Fusion was observed in 4 cases in the 6th week and in 5 cases in the 10th week after surgery in ACB group. No case showed fusion in HAC group. In ACB+HAC group, there was fusion in 3 cases in the 6th week and in 4 cases in the 10th week after surgery. In HAC+BMP group, fusion in 1 case was found in the 4th week, in 5 cases in the 6th week and in 6 cases in the 10th week after surgery. It suggested that ACB, ACB+HAC and HAC+BMP groups showed similar fusion ratio and mechanical strength in the 6th and 10th week after surgery. According to the microstructure analysis of the samples, nHA/collagen had no negative effect when implanted together with ilium autograft. In HAC+BMP group, new bone like tissue was observed in the 2nd week postoperatively, and nearly all of the implanted composites were replaced by mature bone matrix and new bones in 10th week postoperatively. Conclusions: The nHA/collagen, especially combined with rhBMP 2, is a promising bone substitute, for it has quick biodegradation, fine bone bending ability, and high osteoconductivity on posterolateral spinal fusion in rabbits.

Effects of friction stir processing and nano-hydroxyapatite on the microstructure,hardness,degradation rate and in-vitro bioactivity of WE43 alloy for biomedical applications

Nowadays,magnesium alloys are emerging in biomedical implants for their similar properties to natural bones.However,the rapid degradation of magnesium alloys in biological media hinders successful implantation.Refinement of microstructure,as well as reinforcement particles can significantly improve the degradation rate.In this work,multi-pass friction stir processing(FSP)was proposed to synthesize WE43/nano-hydroxyapatite(n HA)surface composite,the microstructure,reinforced particle distribution,micro-hardness,corrosion behavior and in-vitro bioactivity were studied.The subsequent FSP passes of WE43 alloy and WE43/n HA composite refined the grain size which was reduced by 94.29%and 95.92%(2.63 and 1.88μm,respectively)compared to base metal after three passes.This resulted in increasing the microhardness by 120%(90.86 HV0.1)and 135%(105.59 HV0.1)for the WE43 and WE43-n HA,respectively.It is found that increasing FSP passes improved the uniform distribution of n HA particles within the composite matrix which led to improved corrosion resistance and less degradation rate.The corrosion rate of the FSPed WE43/n HA composite after three passes was reduced by 38.2%(4.13 mm/year)and the degradation rate was reduced by 69.7%(2.87 mm/y).This is attributed to secondary phase(Mg24Y5and Mg41Nd5)particle fragmentation and redistribution,as well as a homogeneous distribution of n HA.Additionally,the growing Ca-P and Mg(OH)2layer formed on the surface represented a protective layer that reduced the degradation rate.The wettability test revealed a relatively hydrophilic surface with water contact angle of 49.1±2.2°compared to 71.2±2.1°for base metal.Also,biomineralization test showed that apatite layer grew after immersion 7d in simulated body fluid with atomic ratio of Ca/P 1.60 approaching the stoichiometric ratio(1.67)indicating superior bioactivity of FSPed WE43/n HA composite after three passes.These results raise that the grain refinement by FSP and introduction of n HA particles significantly improved the degradation rate and in-vitro bioactivity of WE43 alloy for biomedical applications.

Fabrication of Multi-layered Composite Scaffolds by Bi-directional Electrospinning Method

A multi-layered composite scaffolds consisting of poly （ L- ne） （ P （LLA-CL） ）, collagen （COL） and chitosan （CS） were fabricated by a bi-directional electrospinnlng method. Synthetic P （LLA-CL） was used as the middle layer to enhance the strength, while natural COL/CS blending （9： 1, v/v） was used as the bioactive surfaces （inner and outer layers ） to improve the biocompatibility. Each three transitional layers were set between inner/outer layer and middle layer for delamination resistance. Scanning electron microscopy （SEM） was used to observe the fiber morphology. The Fourier transform infrared attenuated total reflectance spectroscopy （FTIR-ATR） spectra, X- ray diffraction （XRD） and thermogravimetry （TG） tests were used to analyze the physical properties of the scaffolds. The results showed that the modified clectrospinning method bad no negative effect on the components, crystal structure and thermostability of the scaffolds, but could effectively combine the mechanical property of synthetic material and biocompatibility of natural materials. Such method could be applied to the fabrication of composite scaffolds for vascular, skin. and nerve tissue engineering.

Analysis of Mechanical Behavior of Composite Tissues Using Vibrational Optical Coherence Tomography

Extracellular matrices (ECMs) found in vertebrate tissues are fiber reinforced composite materials that prevent premature mechanical failure, store, transmit, and dissipate mechanical energy generated by the musculoskeletal system. We have developed a new method using optical cohesion tomography and vibrational analysis to non-destructively and non-invasively measure the mechanical properties of composite tissues and polymeric materials. In addition, this method can be used to measure the moduli of individual components of composite materials and perform “mechanical spectroscopy” on materials. In addition, we propose that measurement of the resonant frequency of a material minimizes the viscoelastic behavior of a composite material. This approach simplifies the analysis of mechanical behavior of polymers and others materials that demonstrate time-dependence to their properties.

没食子酸改性酶解-糖基化胶原蛋白-壳聚糖复合膜的制备及表征

为改善猪皮胶原蛋白(PC)可食性膜的机械性能、耐热性和疏水性较差等问题,本研究将猪皮胶原蛋白进行酶解-糖基化改性处理制备出糖基化胶原蛋白(HG-PC)可食性膜,然后通过没食子酸(GA)对糖基化胶原蛋白膜改性制备复合膜(GA-HG-PC膜)。对比分析PC膜、HG-PC膜和GA-HG-PC膜的机械性能、持水性、水蒸气透过率、颜色、热稳定性及抗氧化性,并通过傅里叶变换红外光谱和扫描电子显微镜表征薄膜结构、纳米粒度及Zeta电位仪测定膜液的粒径和电位。结果表明,GA-HG-PC膜的抗拉强度、断裂伸长率分别较PC膜和HG-PC膜提高121.57%、19.00个百分点和91.52%、14.16个百分点;其水蒸气透过率较PC膜和HG-PC膜下降,耐水性显著改善(P<0.05);GA-HG-PC膜的颜色比PC膜和HG-PC膜更深,透明度下降,热稳定性提高;此外,GA-HG-PC膜的内部结构更加稳定,氢键作用力较强,成膜溶液稳定性提高,其1,1-二苯基-2-苦基肼(DPPH)自由基清除率分别较HG-PC膜和PC膜增加10.49和18.26个百分点(P<0.05)。本研究可为改善PC膜的功能特性提供新思路,拓展其在果蔬、水产品、肉制品及烘焙食品等领域的应用,对开发新型可食性蛋白膜具有一定意义。

红鳘鱼胶胶原蛋白对D-半乳糖致衰老小鼠皮肤的抗衰老作用研究

以红鳘鱼胶为原料,酸酶法提取胶原蛋白,通过十二烷基硫酸钠-聚丙烯酰胺凝胶电泳(SDS-PAGE)、氨基酸组成分析等方法进行理化性质分析,并以D-半乳糖建立衰老小鼠模型,探究其对小鼠皮肤含水量、羟脯氨酸含量、皮肤病理形态和抗氧化活性的影响。结果表明,胶原蛋白由2条α链与1条β链组成,为典型的Ⅰ型胶原蛋白,以甘氨酸、丙氨酸、谷氨酸、脯氨酸为特征氨基酸,分别占总氨基酸含量13.890%,8.601%,7.650%和7.124%,且不含色氨酸;动物实验结果表明,经D-半乳糖造模后,MN组小鼠皮肤粗糙、松弛,皱纹数量增多,相较于CN组皮肤水分含量降低了13.52%,羟脯氨酸含量降低了26.20%,抗氧化能力降低,小鼠皮肤真皮层变薄,胶原纤维、弹性纤维含量降低,部分明显断开;红鳘鱼胶胶原蛋白干预后,能够显著改善由于D-半乳糖造成的小鼠背部皮肤水分流失,增强小鼠皮肤组织氧化应激抵抗力,胶原蛋白组皮肤结构基本恢复,皮肤胶原纤维和弹力纤维含量升高,Ⅰ/Ⅲ型胶原蛋白比例升高了9.79%。综上分析,通过红鳘鱼胶制备的胶原蛋白可延缓D-半乳糖引起的皮肤衰老,可为胶原蛋白在化妆品领域的高值化利用提供依据。

多尺度皮革胶原纤维/丁苯橡胶复合材料的制备与性能研究

利用巯丙基三乙氧基硅烷改性皮革胶原纤维(MCF),并将其作为丁苯橡胶(SBR)的补强剂,以提高丁苯橡胶复合材料的拉伸强度和断裂伸长率。结果表明,基于MCF多尺度结构在增韧中的作用及其与橡胶的界面相互作用,提高了MCF在橡胶中的分散,促进了界面应力传递,从而增强了复合材料的机械性能。与纯SBR相比,填充3%(质量分数)MCF的弹性体复合材料拉伸强度从1.6MPa提高到2.1MPa,断裂伸长率从184%提高到247%。

The characterization of acid and pepsin soluble collagen from ovine bones (Ujumuqin sheep)

Ovine bones are the major by-products after slaughtered. The present study was conducted to extract and characterize acid soluble collagens （ASC） and pepsin soluble collagens （PSC） from ovine bones （Ujumuqin sheep）. Ovine bones collagen were identified by sodium dodecyl sulfate-polyacrylamide gel electrophoresis （SDS-PAGE） and liquid chromatography-tan- dem mass spectrometry （LC-MS/MS） as type I collagen. The results of Fourier transform infrared （FTIR） spectra analysis testified the existence of triple superhelical structure in both ASC and PSC, showing pepsin did not disrupt the triple helical structure of ovine bones collagen. Glycine, accounting for one-third of total amino acids, was the major amino acid for ovine bones collagen. Higher imino acid content was responsible for higher thermal denaturation temperature of ovine bones collagen compared to fish collagens. The isoelectric point of ASC was lower than PSC due to the higher content of acidic amino acids. Therefore, this study provides the potential reference for collagen extraction and application of ovine bones by-procduct.

Magnesium/Nano-hydroxyapatite Composite for Bone Reconstruction: The Effect of Processing Method

Nano-ceramic particles can serve as reinforcing agents for metallic materials to improve their mechanical properties.However,it is important to ensure chemical compatibility between the matrix and particles.In the present study,magnesium composites with and without nano-hydroxyapatite(nHA)particles were fabricated for bone reconstruction applications.Two different techniques were used,Conventional Sintering(CS)of powder compacts and Spark Plasma Sintering(SPS)of pre-compacted powder.Results showed that a 10 wt%addition of nHA particles to magnesium,followed by SPS improved the compression strength by 27%.CS did not lead to any significant improvement compared to SPS processing.X-ray diffraction data after CS revealed the formation of unfavorable phases due to chemical reactions between nHA particles and the magnesium matrix,while these phases were absent after SPS processing.The mechanical properties of the specimens fabricated by CS were much inferior to those processed using SPS.The shorter processing time associated with SPS leaded to reduced interaction between nHA particles and the Mg-matrix,compared to CS.

Preparation and Biocompatibility of Porous Poly(vinylalcohol)-Glycosaminoglycan-Collagen Scaffold

This paper aims to prepare a PVA-GAG-COL composite with polyvinyl alcohol (PVA), glycosaminoglycan (GAG) and collagen (COL) by the method of freeze drying and to investigate the feasibility as a tissue engineering scaffold for tissue or organ repairing. In this study, SEM was used to observe the morphology. Biocompatibility was tested by cell culture with the extracted fluid of composite materials. Different proportional scaffolds could be obtained with different concentrations and alcoholysis degree of PVA. Different proportional scaffolds also had different porous structures. SEM proved that large amount of porous structure could be formed. Biocompatibility test showed that the extracted fluid of composite materials was nontoxic, which could promote the adhesion and proliferation of the fibroblast. Fibroblast could grow on the scaffold normally.A porous scaffold for tissue engineering with high water content can be fabricated by PVA, GAG and COL, which has excellent cell biocompatibility. The porous structure shows potential in tissue engineering and cell culture.

丝素胶原蛋白复合支架联合富血小板血浆修复皮肤损伤

背景:胶原与丝素蛋白复合构建的组织工程支架,在皮肤、神经、血管、骨、软骨等组织工程领域应用广泛。富血小板血浆是血液经过2次离心获得的血小板浓缩物,含有多种组织修复需要的生长因子,可促进组织再生与创面愈合。目的:观察丝素胶原蛋白支架复合富血小板血浆在皮肤创面愈合中的作用。方法:分别制备丝素胶原蛋白支架、SD大鼠富血小板血浆。取8周龄SD大鼠48只,每只背部制作2个直径2 cm的全层皮肤缺损创面,分4组处理:空白组缺损处注射生理盐水,单纯支架组缺损处植入丝素胶原蛋白复合支架,富血小板血浆组创缘注射同种异体富血小板血浆,联合组缺损处植入丝素胶原蛋白复合支架+创缘注射同种异体富血小板血浆,每组12只。造模后检测创面愈合率、创面炎症因子水平、创面组织学观察及相关蛋白表达。结果与结论:①联合组造模后第7,14天的创面愈合率大于空白组、单纯支架组、富血小板血浆组(P<0.05)。②联合组造模后第7,14天的肿瘤坏死因子α、白细胞介素6水平均低于空白组、单纯支架组、富血小板血浆组(P<0.05)。③造模后第14天的苏木精-伊红及Masson染色显示,空白组缺损处仅见少量的新生毛细血管与混乱排列的胶原纤维组织;其他3组可见大量的新生毛细血管与腺体样组织,胶原纤维排列较规律,其中以联合组新生血管最多、腺体样组织层次更清晰、胶原纤维排列更规则。免疫组化染色显示,空白组、单纯支架组、富血小板血浆组CD31+细胞密度少于联合组(P<0.05)。④Western blot检测显示,相较于空白组、单纯支架组、富血小板血浆组,联合组创面Ⅰ型胶原、Ⅲ型胶原、基质金属蛋白酶抑制剂1的蛋白表达升高(P<0.05),基质金属蛋白酶3、基质金属蛋白酶9蛋白表达降低(P<0.05)。⑤结果表明,丝素胶原蛋白支架复合富血小板血浆可通过抑制炎症反应、增加微血管密度、调节细胞外基质的代谢平衡来促进皮肤创面愈合。

纤维素纳米晶须提取及其复合膜的制备与表征

以白酒丢糟为原料,采用酸解法提取纤维素纳米晶须(Cellulose nanocrystals, CNCs),将CNCs、胶原蛋白(Collagen, COL)和黄原胶共混制备复合膜.采用单因素及响应面实验确定CNCs的提取工艺,以溶胀性为指标,探讨了CNCs-COL复合膜的制备工艺.利用扫描电镜(Scanning electron microscopy, SEM)、傅里叶变换红外光谱仪(Fourier transform infrared spectrometer, FT-IR)、X-射线衍射仪(X-ray diffractometer, XRD)及热重分析仪(Thermogravimetric, TG)等对LC、CNCs及复合膜的微观形貌、化学结构、晶型结构及热稳定性进行表征.结果表明,CNCs提取工艺条件为盐酸浓度11%,水解时间110 min,水解温度70℃.所提取CNCs呈规则棒状,具有典型纤维素的红外光谱特征,纤维素晶型为Ⅰ型,结晶度为43.91%,热稳定性优于纤维素;当CNCs与COL质量比1∶10,黄原胶质量分数0.5%,复合温度40℃,复合时间2 h时,CNCs-COL复合膜具有良好的溶胀性,具有较规则的孔隙结构,具有优良的热稳定性.研究结果可为白酒丢糟高值化、无害化转化利用及CNCs-COL基医用敷料的开发提供技术支持.

Pores Created by Laser Surface Modification of Poly(vinylalcohol)-Collagen with Glycosaminoglycan Scaffold for Cell Culture in Tissue Engineering

A PVA- GAG- COL composite scaffold is fabricated by polyvinyl alcohol (PVA), glycosaminoglycan (GAG) and collagen (COL). Laser surface modification technology is used to make holes on the surface of the scaffolds. Inside and outside interconnection microporous structure is obtained. Biocompatibility test of the scaffolds shows that PVA- GAG- COL scaffold can promote the adhesion and proliferation of the fibroblast. Also, fibroblast can grow normally on the scaffolds with pore diameter from 115 um to 255 um and pore distance from 500 um to 2000 um. PVA- GAG- COL scaffolds possess excellent cell biocompatibility. The porous structure is suitable for cell culture in tissue engineering.

胶原基生物材料在医学美容领域的研究进展

胶原是哺乳动物体内含量最多的蛋白质,在人体皮肤内的含量约为70%,是细胞外基质的主要成分,对皮肤的弹性、光泽、毛孔和水分等具有重要影响。作为天然高分子材料,胶原具有抗原性低、可吸收降解、美白保湿和填充修复等特性,基于天然胶原、水解胶原和重组人源胶原开发研制的产品可以满足不同患者、不同病症的治疗需求,已被广泛用于医学整形美容领域。纯胶原的湿热稳定性、耐酶解性和力学性能较差,将其与天然高分子材料共混制备复合材料可以弥补单一组分的不足,兼具多种材料的优势,胶原蛋白的复合改性是胶原基生物医用材料的研究热点之一。本文介绍了胶原蛋白、水解胶原和重组人源胶原的结构与性能,分析了胶原基复合材料对纯胶原材料缺陷的改善机理,列举了胶原基生物材料在注射医美、人工皮肤、美容敷贴和日用化妆品领域的应用进展,指出了胶原基材料目前存在的问题及今后的发展前景,以期为胶原基生物材料在医学美容领域的产品开发和临床应用提供参考。

二次胶原纤维吸音、阻燃性能评价及其复合纱布材料的特性研究

目的 对从废弃皮革提取的二次胶原纤维进行一系列性能评价,着重研究它在吸音、阻燃方面的性能,探究二次胶原纤维及其复合纱线、布料在包装领域应用的可能性。方法 采用SEM、氨基酸分析仪、傅里叶变换红外光谱分析、驻波管及氧指数法对二次胶原纤维进行测试,采用万能拉力机对复合纱线、布料进行力学测试。结果 二次胶原纤维具有多孔隙、多层结构的特点,其最佳吸声系数可达0.98,极限氧指数为34.7%,二次胶原纤维复合纱线、布料具有良好的力学性能。结论 实验结果表明,二次胶原纤维具有良好的吸音、阻燃性能,其复合纱线、布料具有良好的力学性能,在包装领域具有良好的应用前景。

鱼皮及其加工制品的研究进展与应用

近年来,随着鱼类加工产量的增加,其加工产生的副产物也随之增多。鱼皮作为鱼类加工副产物之一,含有丰富的蛋白质、氨基酸、矿物质和不饱和脂肪酸等,具有较强的加工潜力,但目前能够将其进行加工的企业较少,通常是将鱼皮直接丢弃,这不仅造成大量的浪费,而且污染环境。本文梳理了鱼皮中的营养成分、胶原蛋白的提取方法以及已有的鱼皮加工制品,对鱼皮在食品、功能性产品、化妆品、医疗和服饰领域等不同方面的研究现状及应用概况进行综述,提出现阶段鱼皮加工应用领域中所存在的问题,并对未来鱼皮加工产品的走向和发展进行展望,以期为鱼类加工副产物的高值化利用提供参考依据,对优化和拓宽我国水产品副产物的研究领域和提升国家经济效益具有重要意义。

胶原膜在引导骨再生技术中的应用和改良研究进展

胶原蛋白是哺乳动物体内最丰富的蛋白质,将其作为主要材料制成的生物膜具有良好的理化性质和生物学功能,被广泛用于骨组织工程等医学领域。在引导骨再生技术中,以胶原膜作为可吸收屏障膜被广泛应用,但仍存在降解不可控、机械强度低等缺陷。为了改进这些不足,通过交联、矿化、表面修饰等方法,新型胶原膜的不断开发和应用成为该领域未来的发展趋势。本文就胶原膜在引导骨再生技术中的应用和改良进行综述,以期为新型胶原膜的研发提供新的思路。

The development of collagen based composite scaffolds for bone regeneration

Bone is consisted of bone matrix,cells and bioactive factors,and bone matrix is the combination of inorganic minerals and organic polymers.Type I collagen fibril made of five triple-helical collagen chains is the main organic polymer in bone matrix.It plays an important role in the bone formation and remodeling process.Moreover,collagen is one of the most commonly used scaffold materials for bone tissue engineering due to its excellent biocompatibility and biodegradability.However,the low mechanical strength and osteoinductivity of collagen limit its wider applications in bone regeneration field.By incorporating different biomaterials,the properties such as porosity,structural stability,osteoinductivity,osteogenicity of collagen matrixes can be largely improved.This review summarizes and categorizes different kinds of biomaterials including bioceramic,carbon and polymer materials used as components to fabricate collagen based composite scaffolds for bone regeneration.Moreover,the possible directions of future research and development in this field are also proposed.

Comparative evaluation of the physicochemical properties of nano-hydroxyapatite/collagen and natural bone ceramic/collagen scaffolds and their osteogenesis-promoting effect on MC3T3-E1 cells

The use of various types of calcium phosphate has been reported in the preparation of repairing materials for bone defects.However,the physicochemical and biological properties among them might be vastly different.In this study,we prepared two types of calcium phosphates,nano-hydroxyapatite(nHA)and natural bone ceramic(NBC),into 3D scaffolds by mixing with type I collagen(CoL),resulting in the nHA/CoL and NBC/CoL scaffolds.We then evaluated and compared the physicochemical and biological properties of these two calcium phosphates and their composite scaffold with CoL.Scanning electron microscopy(SEM),X-ray photoelectron spectroscopy(XPS),Fourier-transform infrared spectroscopy(FTIR),X-ray diffraction spectroscopy(XRD)and compressive tests were used to,respectively,characterize the morphology,composition,distribution and the effect of nHA and NBC to collagen.Next,we examined the biological properties of the scaffolds using cytotoxicity testing,flow cytometry,immunofluorescence staining,biocompatibility testing,CCK-8 assays and RT-PCR.The results reflected that the Ca2t released from nHA and NBC could bind chemically with collagen and affect its physicochemical properties,including the infrared absorption spectrum and compression modulus,among others.Furthermore,the two kinds of scaffolds could promote the expression of osteo-relative genes,but showed different gene induction properties.In short,NBC/CoL could promote the expression of early osteogenic genes,while nHA/CoL could upregulate late osteogenic genes.Conclusively,these two composite scaffolds could provide MC3T3-E1 cells with a biomimetic surface for adhesion,proliferation and the formation of mineralized extracellular matrices.Moreover,nHA/CoL and NBC/CoL had different effects on the period and extent ofMC3T3-E1 cell mineralization.

In vitro characterization of novel nanostructured collagen-hydroxyapatite composite scaffolds doped with magnesium with improved biodegradation rate for hard tissue regeneration

New materials are required for bone healing in regenerative medicine able to temporarily substitute damaged bone and to be subsequently resorbed and replaced by endogenous tissues.Taking inspiration from basic composition of the mammalian bones,composed of collagen,apatite and a number of substitution ions,among them magnesium(Mg2+),in this work,novel composite scaffolds composed of collagen(10%)-hydroxyapatite(HAp)(90%)and collagen(10%)-HAp(80%)-Mg(10%)were developed.The lyophilization was used for composites preparation.An insight into the nanostructural nature of the developed scaffolds was performed by Scanning Electron Microscopy coupled with Energy Dispersive X-Ray and Transmission Electron Microscopy coupled with Energy Dispersive X-Ray.The HAp nanocrystallite clusters and Mg nanoparticles were homogeneously distributed within the scaffolds and adherent to the collagen fibrils.The samples were tested for degradation in Simulated Body Fluid(SBF)solution by soaking for up to 28 days.The release of Mg from collagen(10%)-HAp(80%)-Mg(10%)composite during the period of up to 21 days was attested,this composite being characterized by a decreased degradation rate with respect to the composite without Mg.The developed composite materials are promising for applications as bone substitute materials favouring bone healing and regeneration.