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Effects of serum proteins on corrosion rates and product bioabsorbability of biodegradable metals

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Regenerative Biomaterials 2024年第1期3卷 132-148页

作者： Hongjie Zhang Xin li Zehua Qu Wanqian Zhang Qunsong Wang dinglingge Cao Yaoben Wang Xin Wang Yang Wang lin Yu jiandong ding State key laboratory of molecular engineering of polymers Department of Macromolecular ScienceFudan UniversityShanghai 200438China

Corrodible metals are the newest kind of biodegradable materials and raise a new problem of the corrosion ***,the removal of the precipitated products has been unclear and even largely ignored in ***,we find that albumin,an abundant macromolecule in serum,enhances the solubility of corrosion products of iron in blood mimetic Hank’s solution *** is universal for other main biodegradable metals such as magnesium,zinc and polyester-coated *** also influences corrosion rates in diverse trends in Hank’s solution and normal *** on quantitative study theoretically and experimentally,both the effects on corrosion rates and soluble fractions are interpreted by a unified mechanism,and the key factor leading to different corrosion behaviors in corrosion media is the interference of albumin to the Ca/P passivation layer on the metal *** work has illustrated that the interactions between metals and media macromolecules should be taken into consideration in the design of the next-generation metal-based biodegradable medical devices in the formulism of precision *** improved Hank’s solution in the presence of albumin and with a higher content of initial calcium salt is suggested to access biodegradable metals potentially for cardiovascular medical devices,where the content of calcium salt is calculated after consideration of chelating of calcium ions by albumin,resulting in the physiological concentration of free calcium ions.

关键词： biodegradable metal macromolecule albumin corrosion bioabsorbability iron polylactide magnesium zinc

Preparation of a gene-engineering mutant of bacteriorhodopsin BR-D96V and corresponding poly(vinyl alcohol)-based functional composite films

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science Bulletin 2010年第33期 3829-3834页

作者： ZHAO YingChun1,2,MING Ming1,HONG Jie2,MA DeWang1,WU Jia1,lI QingGuo3,HUANG WeiDa2 & ding jiandong1 1 key laboratory of molecular engineering of polymers of Ministry of Education,department of macromolecular science,fudan university,shanghai 2..433,china 2 department of Biochemistry,School of life sciences,fudan university,shanghai 2..433,china 3 department of Physiology and Biophysics,School of life sciences,fudan university,shanghai 2..433,china

Bacteriorhodopsin(BR)exhibits,as a membrane protein in Halobacterium salinarum,unique photoresponsive behaviors,and shows promise as a functional information material.A new mutant of BR with the 96th aspartic acid replaced by valine(BR-D96V)was obtained and then a composite film of BR-D96V in a synthetic polymer matrix was prepared in this *** mutant BR-D96V was expressed in a bacterio-opsin deficient halobacterial strain(l33)by gene *** valine is very hydrophobic,this point mutant keeps the basic biological activities,namely,photoelectric and photochromic ***,the lifetime of M intermediate in the BR mutant is nearly two orders of magnitude longer than that of wild-type BR in neutral aqueous solution,which benefits its potential application as an information *** M lifetime is further significantly prolonged after embedding BR-D96V into poly(vinyl alcohol)(PVA).It was also found that BR-D96V is very sensitive to water content in comparison with wild-type BR and another BR mutant.

关键词： synthetic polymer organic photoelectric material composite film bacteriorhodopsin site-specific mutagenesis photore-sponsive protein

Establishment of coverage-mass equation to quantify the corrosion inhomogeneity and examination of medium effects on iron corrosion

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Regenerative Biomaterials 2023年第1期10卷 486-497页

作者： Xin li jiandong ding State key laboratory of molecular engineering of polymers Department of Macromolecular ScienceFudan UniversityShanghai 200438China

Metal corrosion is important in the fields of biomedicine as well as construction and transportation *** most corrosion occurs inhomogeneously,there is so far no satisfactory parameter to characterize corrosion ***,we employ the Poisson raindrop question to model the corrosion process and derive an equation to relate corrosion coverage and corrosion *** resultant equation is named coverage-mass equation,abbreviated as C-M *** also suggest corrosion mass at 50%coverage,termed as half-coverage mass Mcorro50%,as an inhomogeneity parameter to quantify corrosion *** equation is confirmed and the half-coverage mass Mcorro50%is justified in our experiments of iron corrosion in five aqueous media,normal saline,phosphate-buffered saline,Hank’s solution,deionized water and artificial seawater,where the former three ones are biomimetic and very important in studies of biomedical *** half-coverage mass Mcorro50%is proved to be more comprehensive and mathematically convergent than the traditional pitting *** corrosion is detected using visual observation,scanning electron microscopy with a build-in energy dispersive spectrometer,inductive coupled plasma emission spectrometry and electrochemical *** rates and inhomogeneity extents of iron corrosion are compared among the five aqueous *** factors underlying the medium effects on corrosion rate and inhomogeneity are discussed and *** rates of iron in the five media differ about 7-fold,and half-coverage mass values differ about *** fastest corrosion and the most significant inhomogeneity occur both in biomimetic media,but not the same *** new equation(C-M equation)and the new quantity(half-coverage mass)are stimulating for dealing with a dynamic and stochastic process with global inhomogeneity including but not limited to metal *** findings are particularly meaningful for research and development of nex

关键词： biomaterials biodegradable metal corrosion inhomogeneity coverage-mass equation biomimetic media biodegradable medical device

A composite strategy to fabricate high-performance biodegradable stents for tissue regeneration

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science china Materials 2018年第8期61卷 1132-1134页

作者： jiandong ding State key laboratory of molecular engineering of polymers Department of Macromolecular Science Fudan University

While most of the present medical implants are nonbiodegradable,biodegradable materials are thought to replace many nonbiodegradable ones in the future,which is dependent on development of the corresponding core techniques of biomaterials[1-4].Much progress has been made in the field of biodegradable materials during the last decade[5-7].

关键词： A composite strategy to fabricate high-performance biodegradable stents for tissue regeneration

Effects of l-lactic acid and D,l-lactic acid on viability and osteogenic differentiation of mesenchymal stem cells

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Chinese science Bulletin 2013年第20期58卷 2404-2412,1-3页

作者： HE Yao WANG WeiRan ding jiandong State key laboratory of molecular engineering of polymers Department of Macromolecular Science Advanced Materials Laboratory Fudan University

Poly(lactic acid) (PlA) and other aliphatic polyesters containing the unit of lactic acid are very popular biodegradable materials. While the degradation products, lactic acids, have been worried to bring with negative influence on biocompatibility, the focused experimental studies are less reported. This study is aimed at an in vitro examination of cytotoxicity of both l-lactic acid and D,l-lactic acid. Mesenchymal stem cells (MSCs) derived from rat bone marrow are employed to test the cytotoxicity of the lactic acids. Considering that the addition of lactic acids not only introduces lactate groups but also alters medium pH and ion strength, these three candidate effects are examined in a decoupled way by setting different comparison groups. The results confirm that the change of medium pH is the predominant factor. It has also been found that D-lactate is more cytotoxic than l-lactate at high concentrations. Yet, either l-or D,l-lactic acids seem acceptable in most of medical applications, because the cytotoxicity is significant only when the concentrations are as high as 20 mmol/l for both of them.

关键词：骨髓间充质干细胞 l-乳酸成骨分化细胞毒作用能力细胞毒性可生物降解生物相容性

Preparation of a cross-linked gelatin/bacteriorhodopsin film and its photochromic properties

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science china Chemistry 2011年第2期54卷 405-409页

作者： WANG YaZhuo WU Jia MA DeWang ding jiandong key laboratory of molecular engineering of polymers of Ministry of Education Department of Macromolecular ScienceFudan UniversityShanghai 200433China

Bacteriorhodopsin (BR) is a photochromic membrane protein isolated from a strain of *** of BR into a polymeric matrix enables the application of the photoactive protein as an optical *** this work,a chemically crosslinked BR/gelatin film was *** cross-linked film was found to be highly stable even under extreme alkaline or detergent circumstance while BR maintained its *** treatments of base and detergents also led to dramatic prolongation of the lifetime of M photoproduct,which might be beneficial for potential applications such as information *** BR/gelatin film was demonstrated to tentatively record a simple pattern.

关键词： bacteriorhodopsin photochromic protein natural macromolecule functional polymer photoresponsive materials

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engineering 2022年第6期8卷 31-45页

作者： Jingming Gao Xiaoye Yu Xinlei Wang Yingning He jiandong ding State key laboratory of molecular engineering of polymers Department of Macromolecular ScienceFudan UniversityShanghai 200438China

An appropriate cell microenvironment is key to tissue engineering and regenerative *** the factors that influence the cell microenvironment is a fundamental research topic in the fields of cell biology,biomaterials,tissue engineering,and regenerative *** cell microenvironment consists of not only its surrounding cells and soluble factors,but also its extracellular matrix(ECM)or nearby external biomaterials in tissue engineering and *** review focuses on six aspects of bioma-terial-related cell microenvironments:①chemical composition of materials,②material dimensions and architecture,③material-controlled cell geometry,④effects of material charges on cells,⑤matrix stiff-ness and biomechanical microenvironment,and⑥surface modification of *** present chal-lenges in tissue engineering are also mentioned,and eight perspectives are predicted.

关键词： Tissue engineering Regenerative medicine Biomaterials Cell microenvironment Porous scaffold Surface patterning Cell-material interactions

Distribution of bone marrow stem cells in large porous polyester scaffolds

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Chinese science Bulletin 2009年第17期54卷 2968-2975页

作者： WANG Zhen ZHANG Zheng ZHANG JunChuan SHE ZhenJue ding jiandong key laboratory of molecular engineering of polymers Ministry of Education Department of Macromolecular Science Fudan University Shanghai 200433 China department of Anatomy Embryology and Histology Shanghai Medical School Fudan University Shanghai 200032 China

This work examined the optimal syringing depth during in vitro cell loading in order to even cell distribution after syringing a drop of cell suspension in cylinder poly(lactide-co-glycolide) (PlGA) porous scaffolds. The scaffolds of 10 mm height and 10 mm diameter were fabricated via room-temperature compression molding & particulate leaching technique based on spherical porogens. In vitro tests were employed for such examinations: a global observation of a cell-loaded scaffold stained by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) technique and a quantitative measurement of spatial distribution of cells after slicing the cell-loaded scaffolds into layers. It was found that an even distribution of cells was soon achieved only if the initial cell suspension was seeded on the layer that was below the top surface but above the middle of scaffolds. The availability of in vitro osteoblastic differentiation of rat bone marrow stem cells in such a kind of spherical-pore PlGA scaffolds was meanwhile confirmed.

关键词：细胞分布多孔支架聚酯骨髓体外培养压缩成型共聚物乙醇酸

Coordination Insertion Mechanism of Ring-Opening Polymerization of lactide Catalyzed by Stannous Octoate

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Chinese Journal of Chemistry 2021年第7期39卷 1965-1974页

作者： Weihan Rao Caiyun Cai Jingyu Tang Yiman Wei Caiyun Gao lin Yu jiandong ding State key laboratory of molecular engineering of polymers Department of Macromolecular ScienceFudan UniversityShanghai200438 China Zhuhai fudan Innovation Institute ZhuhaiGuangdong519000 China

Main observation and conclusion Ring-opening polymerization(ROP)of cyclic esters in the presence of stannous octoate(Sn(Oct)2)is the main way to obtain biodegradable aliphatic polyesters,an important family of biodegradable polymers which have been widely used and still rapidly developed in the fields of biomedical polymers and environment-friendly materials.

关键词： Ring-opening polymerization Transition states Curtin-Hammett principle Polylactide Density functional theory