共查询到20条相似文献,搜索用时 31 毫秒
1.
Qiu Xia Ji Qing Sheng Zhao Jing Deng Rui Lü 《Journal of materials science. Materials in medicine》2010,21(8):2435-2442
The aim of this paper was to evaluate the application potential of CS–HTCC/GP–0.1%Chx thermosensitive hydrogel which was synthesized
using chitosan (CS), quaternized CS, and α,β-glycerophosphate (α,β-GP) loading with 0.1% chlorhexidine (Chx) (w/v) for periodontal
treatment. An aqueous solution of CS–HTCC/GP–0.1%Chx was transformed into hydrogel at 6 min when the temperature was increased
to 37°C. The scan electron microscopy (SEM) image of the gel was a porous, loose and crosslinked network. In vitro, Chx released
over 18 h from the CS–HTCC/GP thermosensitive hydrogel in artificial saliva pH 6.8. Release rate could be controlled through
adjustment of α,β-GP or Chx concentration. CS–HTCC/GP–0.1%Chx thermosensitive hydrogel exhibited excellent inhibitory activity
against primary periodontal pathogens. CS–HTCC/GP–0.1%Chx thermosensitive hydrogel had no acute toxicity; the maximum tolerated
dose in rats was 400 mg/ml. All results indicated that CS–HTCC/GP–0.1%Chx thermosensitive hydrogel is a strong candidate as
a local drug delivery system for periodontal treatment. 相似文献
2.
Design and optimization of thermosensitive nanoemulsion hydrogel for sustained-release of praziquantel 总被引:1,自引:0,他引:1
Zhaotong Cong Xue Peng Bei Wei Yu Wang Jincheng Li 《Drug development and industrial pharmacy》2017,43(4):558-573
Objective: This work aimed to develop an alternative sustained-release thermosensitive praziquantel-loaded nanoemulsion (PZQ-NE) hydrogel for better schistosomiasis treatment.Significance: PZQ-NE-dispersed chitosan/glycerol 2-phosphate disodium/HPMC (NE/CS/β-GP/HMPC) hydrogel was successfully prepared to improve bioavailability of PZQ.Methods: Solubility tests and pseudo-ternary phase diagrams were applied to screen optimal oils, surfactants and co-surfactants of NE. The hydrogels were characterized for gelling time, surface exudates, rheological properties and in vitro drug release. Formulation optimization of NE/CS/β-GP/HMPC hydrogel was conducted by Box–Behnken experimental design combined with response surface methodology. In vitro cytotoxicity of hydrogel was studied by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide method. The sustained-release property of PZQ in NE and optimized hydrogel was evaluated by pharmacokinetic study in rabbits.Results: The formulation of PZQ-NE consisted of mass ratio of 12.5% capryol 90 containing PZQ (160?mg/g), 40% cremophor RH 40/tween 20 and transcutol HP (S/CoS?=?2:1), 47.5% deionized water. PZQ releasing from NE/CS/β-GP/HMPC hydrogels was best fitted to Higuchi model and governed by diffusion. Rheological investigation evidenced the themosensitive gelation of different hydrogel systems and their gel-like character at 37?°C. The optimized hydrogel formulation consisted of HPMC solution (103.69?mg/g), 3.03% (w/v) chitosan and 14.1% (w/v) β-GP showed no cytotoxicity when the addition of NE was no more than 100?mg/g. Pharmacokinetic parameters indicated that NE/CS/β-GP/HMPC hydrogel can significantly slow down drug elimination, prolong mean residence time and improve bioavailability of PZQ.Conclusions: NE/CS/β-GP/HMPC hydrogel possessed sustained-release property and could be an alternative antischistosomal drug delivery system with improved therapeutic effect. 相似文献
3.
Sun B Ma W Su F Wang Y Liu J Wang D Liu H 《Journal of materials science. Materials in medicine》2011,22(9):2111-2118
Type I collagen was added to the composite chitosan solution in a ratio of 1:2 to build a physical cross-linked self-forming
chitosan/collagen/β-GP hydrogel. Osteogenic properties of this novel injectable hydrogel were evaluated. Gelation time was
about 8 min which offered enough time for handling a mixture containing cells and the subsequent injection. Scanning electronic
microscopy (SEM) observations indicated good spreading of bone marrow mesenchymal stem cells (BMSCs) in this hydrogel scaffold.
Mineral nodules were found in the dog-BMSCs inoculated hydrogel by SEM after 28 days. After subcutaneous injection into nude
mouse dorsum for 4 weeks, partial bone formation was observed in the chitosan/collagen/β-GP hydrogel loaded with pre-osteodifferentiated
dog-BMSCs, which indicated that chitosan/collagen/β-GP hydrogel composite could induce osteodifferentiation in BMSCs without
exposure to a continual supply of external osteogenic factors. In conclusion, the novel chitosan/collagen/β-GP hydrogel composite
should prove useful as a bone regeneration scaffold. 相似文献
4.
An injectable thermo-sensitive double crosslinking hydrogel based on thiolated chitosan (CS-TGA)/beta-glycerophosphate (β-GP)
was prepared by combining physical and chemical crosslinking. The effect of the concentrations of CS-TGA and β-GP on gelation
temperature of CS-TGA-GP hydrogel was investigated. The gelation and mechanical properties of CS-TGA-GP in situ gel system
were studied by oscillatory rheology and unconfined compression testing. By the physical interaction of CS-TGA and β-GP, CS-TGA-GP
system undergoes a fast gelation at body temperature within 2 min. In addition, CS-TGA-GP hydrogel contains a low concentration
of β-GP, which significantly decreases the toxicity of the gel. Owing to the chemical crosslinking of disulfide bonds, the
gel is durable and possesses high-mechanical strength without introducing any potential cytotoxicity. The integrity of CS-TGA-GP
hydrogel maintains for more than 30 days both in vitro and in vivo, and the interior morphology visualized by scanning electron
microscopy reveals that the gel has interconnected porous network structure. In vitro release behavior of protein from CS-TGA-GP
hydrogel was investigated using BSA as model protein. There is a sustained protein release from the gel without any initial
burst. In vitro cytotoxicity, hemolysis, and histopathological analysis reveal that the gel is biocompatible. These features
indicate that CS-TGA-GP hydrogel is a promising candidate for injectable protein delivery system and biomedical applications. 相似文献
5.
Preparation,fabrication and biocompatibility of novel injectable temperature-sensitive chitosan/glycerophosphate/collagen hydrogels 总被引:1,自引:0,他引:1
Kedong Song Mo Qiao Tianqing Liu Bo Jiang Hugo M. Macedo Xuehu Ma Zhanfeng Cui 《Journal of materials science. Materials in medicine》2010,21(10):2835-2842
This paper introduces a novel type of injectable temperature-sensitive chitosan/glycerophosphate/collagen (C/GP/Co) hydrogel
that possesses great biocompatibility for the culture of adipose tissue-derived stem cells. The C/GP/Co hydrogel is prepared
by mixing 2.2% (v/v) chitosan with 50% (w/w) β-glycerophosphate at different proportions and afterwards adding 2 mg/ml of
collagen. The gelation time of the prepared solution at 37°C was found to be of around 12 min. The inner structure of the
hydrogel presented a porous spongy structure, as observed by scanning electron microscopy. Moreover, the osmolality of the
medium in contact with the hydrogel was in the range of 310–330 mmol kg−1. These analyses have shown that the C/GP/Co hydrogels are structurally feasible for cell culture, while their biocompatibility
was further examined. Human adipose tissue-derived stem cells (ADSCs) were seeded into the developed C/GP and C/GP/Co hydrogels
(The ratios of C/GP and C/GP/Co were 5:1 and 5:1:6, respectively), and the cellular growth was periodically observed under
an inverted microscope. The proliferation of ADSCs was detected using cck-8 kits, while cell apoptosis was determined by a
Live/Dead Viability/Cytotoxicity kit. After 7 days of culture, cells within the C/GP/Co hydrogels displayed a typical adherent
cell morphology and good proliferation with very high cellular viability. It was thus demonstrated that the novel C/GP/Co
hydrogel herein described possess excellent cellular compatibility, representing a new alternative as a scaffold for tissue
engineering, with the added advantage of being a gel at the body’s temperature that turns liquid at room temperature. 相似文献
6.
Dan-Dan Li Jian-Feng Pan Qiu-Xia Ji Xin-Bo Yu Ling-Shuang Liu Hui Li Xiao-Ju Jiao Lei Wang 《Journal of materials science. Materials in medicine》2016,27(8):134
A novel injectable chitosan thermosensitive hydrogel was designed as a target multi-effect scaffold for endogenous repair of the periodontium. The hydrogel complex was designed by embedding chitosan nanoparticles (CSn) loaded with bone morphogenetic protein-2 plasmid DNA (pDNA-BMP2) into a chitosan (CS)-based hydrogel with α,β-glycerophosphate (α,β-GP), termed CS/CSn(pDNA-BMP2)-GP. Characterization, the in vitro release profile for pDNA-BMP2, and cytocompatibility to human periodontal ligament cells (HPDLCs), were then conducted. The average diameter of the CSn(pDNA-BMP2) was 270.1 nm with a polydispersity index (PDI) of 0.486 and zeta potential of +27.0 mv. A DNase I protection assay showed that CSn could protect the pDNA-BMP2 from nuclease degradation. Encapsulation efficiency and loading capacity of CSn(pDNA-BMP2) were more than 80 and 30 %, respectively. The sol–gel transition time was only 3 min when CSn(pDNA-BMP2) was added into the CS/α,β-GP system. Scanning electron microscopy showed that CSn(pDNA-BMP2) was randomly dispersed in a network with regular holes and a porous structure. Weighting method showed the swelling ratio and degradation was faster in medium of pH 4.0 than pH 6.8. An in vitro pDNA-BMP2 release test showed that the cumulative release rate of pDNA-BMP2 was much slower from CS/CSn-GP than from CSn in identical release media. In release media with different pH, pDNA-BMP2 release was much slower at pH 6.8 than at pH 4.0. Three-dimensional culture with HPDLCs showed good cell proliferation and the Cell-Counting Kit-8 assay indicated improved cell growth with the addition of CSn(pDNA-BMP2) to CS/α,β-GP. In summary, the CS/CSn(pDNA-BMP2)-GP complex system exhibited excellent biological properties and cytocompatibility, indicating great potential as a gene delivery carrier and tissue regeneration scaffold for endogenous repair of the periodontium. 相似文献
7.
A novel method was developed to obtain N-(2-hydroxy)-propyl-3-trimethylammonium chitosan chloride (HTCC) using glycidyl trimethyl ammonium chloride (GTMAC) and chitosan
in a homogeneous system. The factors affecting the degree of substitution (DS) of HTCC, including the amount of perchloric
acid, the reaction temperature, and the reaction time, were especially investigated. Under optimal conditions (i.e., with
2.0, 1.9, and 15 g of chitosan, perchloric acid, and GTMAC, respectively), chitosan was pre-reacted with GTMAC at 60 °C, and
then the reaction was continued at 80 °C for 8 h. The as-produced HTCC had a DS of 86.9%. Its structure was characterized
by Fourier transform infrared spectroscopy and nuclear magnetic resonance. Moreover, it had a good solubility in water within
a wide pH range. Besides, the composite was formed from HTCC loaded on bentonite surface. 相似文献
8.
Wei-Fang LIU Chuan-Zhen KANG Ming KONG Yang LI Jing SU An YI Xiao-Jie CHENG Xi-Guang CHEN 《材料科学前沿(英文版)》2012,6(3):250
Chitosan/α, β-glycerophosphate (CS/α, β-GP) thermo-sensitive hydrogels presented flowable solution state at low temperature and semisolid hydrogel when the ambient temperature increased. In this research, different concentrations of metronidazole encapsulated, CS and α, β-GP, as well as different acid solvents, were chosen to evaluate their influences on the drug release behaviors from CS/α, β-GP hydrogels. It was found that there was a sustaining release during the first 3 h followed by a plateau. SEM images showed that drugs were located both on the surface and in the interior of hydrogels. The optimal preparation conditions of this hydrogel for drug release were as follows: 1.8% (w/v) CS in HAc solvent, 5.6% (w/v) α, β-GP and 5 g/L metronidazole encapsulation. Cytotoxicity evaluation found no toxic effect. In order to control the release rate, 2.5 g/L chitosan microspheres with spherical shape and smooth surface were incorporated, and it was found that the initial release process was alleviated, while drug concentration had no obvious effect on the release rate. It could be concluded that the metronidzole release behaviors could be optimized according to practical applications. 相似文献
9.
In vitro characterization of chitosan scaffolds: influence of composition and deacetylation degree 总被引:2,自引:0,他引:2
Seda Tiğli R Karakeçili A Gümüşderelioğlu M 《Journal of materials science. Materials in medicine》2007,18(9):1665-1674
In this study, the influence of degree of deacetylation (DD) and composition on some structural and biological properties
of chitosan scaffolds were examined in vitro. 3D chitosan scaffolds of 2% (w/v) and 3% (w/v) composition in different DDs
i.e. 75–85% and >85% were prepared by freeze-drying method at −80 °C. We noticed that >85% deacetylated chitosan scaffolds
of 2% (w/v) composition has a highly interconnected morphological structure having ∼100 μm pore size with 0.0917 N/mm2 compression modulus. L929 fibroblastic cells were cultured on chitosan scaffolds in order to evaluate their biocompatibilities.
Cell culture studies demonstrated that fibroblastic cell attachment and proliferation is affected by DD. The higher deacetylated
chitosan scaffolds strongly supported the attachment and proliferation when compared with the lower deacetylated scaffolds.
MTT assay indicated that >85% deacetylated chitosan scaffolds of 2% (w/v) composition, having the highest specific growth
rate 0.017 h−1 of all, was found to be the most suitable for cell culture studies and a potential candidate for tissue engineering with
enhanced biostability and good biocompatibility. 相似文献
10.
In this study, a series of CaO–SiO2–MgO composites with different β-CaSiO3 (CS)/Mg2SiO4 (M2S) composite ratios were prepared to produce new bioactive and biodegradable biomaterials for potential bone repair. The mechanical
properties of CS–M2S composites increased steadily with the increase of M2S ratios in composites. Dissolution tests in Tris–HCl buffer solution showed obvious differences with different CS initial
composite ratio in composites. The dissolution rate increased with the increase of CS composite ratio, which suggested that
the solubility of composites could be tailored by adjusting the initial CS/M2S composite ratio. Formation of bone-like apatite on a range of CS–M2S composites with CS weight percentage ranging from 0 to 100 has been investigated in simulated body fluid (SBF). The presence
of bone-like apatite layer on the composite surface after soaking in SBF was demonstrated by X-ray diffraction (XRD), field
emission scanning electron microscopy (FESEM). The results showed that the apatite formation ability of the CS–M2S composite with 70% CS was detected after 10 days immersion. In vitro cell experiments showed that the 50 and 70% CS composites
supported greater osteoblast-like cell proliferation as compared with pure M2S (p < 0.05). The results of this study suggested that the CS–M2S composites with 50 and 70% initial CS composite amount might be more suitable for preparation of bone repair materials. 相似文献
11.
The near monodispersed ibuprofen-loaded superparamagnetic alginate (AL/IBU/Fe3O4) nanoparticles with particles size less than 200 nm were prepared via the facile heterogeneous coprecipitation of the superparamagnetic
Fe3O4 nanoparticles, sodium alginate (AL) and the model drug ibuprofen (IBU) from the aqueous dispersion. Then the chitosan multilayers
were self-assembled onto the AL/IBU/Fe3O4 nanoparticles to produce novel magnetic-targeted controlled release drug delivery system, with chitosan as the polycation
(CS) and the carboxymethyl chitosan (CMCS) as the polyanion. The drug controlled releasing behaviors of the AL/IBU/Fe3O4 nanoparticles and the CS multilayers encapsulated ibuprofen-loaded superparamagnetic alginate ((AL/IBU/Fe3O4)@(CS–CMCS)3) nanoparticles were compared in the different pH media. In media with the same pH value, the encapsulated vessels exhibited
the slower releasing rate. 相似文献
12.
A. Champa Jayasuriya Shane Kibbe 《Journal of materials science. Materials in medicine》2010,21(2):393-398
The aim of this study was to prepare bone like mineral (BLM) layers rapidly on the exterior surfaces of chitosan (CS) microparticles
(MPs). The CS MPs were fabricated using a scale-up double emulsification method. The CS MPs were in the spherical shape and
the size of 30–60 μm. The MPs were then placed in 5× concentrated simulated body fluid (5 × SBF) and allowed to undergo biomineralization
to form a BLM layers on the surface of CS MPs at 37°C over a 24 h period. The BML layers on the exterior surface of CS MPs
were characterized using wide angle X-ray diffraction (XRD), Fourier transform infrared microscopy (FTIR), and scanning electron
microscopy (SEM). Insulin like growth factor-1 (IGF-1) was dissolved at a concentration of 1 μg/ml in 5 × SBF to incorporate
into the BLM layer. The CS MPs (100 mg) were incubated in a sample of 4 ml of 5 × SBF containing IGF-1 at a concentration
of 1 μg/ml for 24 h. The IGF-1 release from BML layers on CS MPs were studied by placing MPs in 4 ml of phosphate buffered
saline (PBS) and incubating MPs at 37°C for 30 days. Samples (100 μl) were taken over the course of the 30 days and analyzed
using Enzyme-linked Immunosorbent assay (ELISA). The release IGF-1 from BML layers was in a burst manner followed by a sustained
release during the 30-day period. This study suggests that the CS MPs have the potential to be used to help deliver therapeutic
drugs to localized areas and hence increase and accelerate bone growth. 相似文献
13.
Low-stress creep behaviour of a two-phase Zr–2.5%Nb alloy, differently heat treated, has been investigated using helical test
specimens. The phase diagram of the α (hcp) + β (bcc) alloy is characterized by the monotectoid reaction at 893 ± 10 K: β
1 → (α + β
2) where β
1 (Zr–20Nb) and β
2 (Zr–80Nb) have widely differing compositions. At the creep testing temperature, 818 K, which is close to but below the monotectoid
temperature, the creep rate for samples with the equilibrium α + β
2 structure has been found to be considerably higher, over an order of magnitude, than that in samples with the metastable
α + β
1 structure. Microstructural changes accompanying the markedly enhanced creep rate for the α + β
2 structure at stresses as low as 1–4 MPa have been explained in terms of the relative stability of the β
1 and the β
2 phases during the creep process. An attempt has been made to elicit the likely mechanism underlying the observed enhancement
of creep rate and the changes in morphology, composition and volume fraction of the β phase. 相似文献
14.
Optimizing the hot-forging process parameters for connecting rods made of PM titanium alloy 总被引:1,自引:0,他引:1
J. W. Qiu Y. Liu B. Liu Y. B. Liu B. Wang Earle Ryba H. P. Tang 《Journal of Materials Science》2012,47(8):3837-3848
In order to optimize the processing parameters of a new low-cost titanium alloy connecting rod made of powder forging, the
deformation behavior of an α + β type Ti–1.5Fe–2.25Mo (wt%) alloy produced by elemental powder metallurgy (PM) route was studied
using isothermal compression tests. The constitutive equations and a processing map were established to characterize the flow
behavior and predict the optimum deformation parameters. The calculated apparent activation energy was 257.73 kJ/mol for deformation
in the α + β phase region and 378.01 kJ/mol in the β phase region. Two deformation mechanism domains were found: α + β → β
phase transformation and dynamic recrystallization. The results show that the optimum deformation parameters for the present
alloy are (700–800 °C, 10−1.7–1 s−1) and (800–900 °C, 10−2–10 s−1). Based on these results, a finite element method (FEM) simulation of the hot-forming of a connecting rod was conducted,
and the simulated results have been successfully used in an industrial forging of the connecting rod. 相似文献
15.
S. A. Voronov I. D. Goncharov A. Yu. Kashin N. N. Skasyrskaya V. P. Tukmakov 《Technical Physics Letters》1998,24(6):414-416
It is established by x-ray structure analysis that the oxide film formed on the surface of uranium during oxidation by dry
oxygen at pressures of 0.1–0.001 Pa and temperatures of 500–700 °C for several hours consists of UO2 with U4O9 inclusions. Near the surface of the uranium the temperature of the α→β phase transition is lowered by 150–160 °C in comparison with the transition in the bulk of the metal, and the low-temperature
stabilization of the β phase of uranium is observed.
Pis’ma Zh. Tekh. Fiz. 24, 7–11 (June 12, 1998) 相似文献
16.
Bin Tang Hong-Chao Kou Yi-Hong Wang Zhi-Shou Zhu Feng-Shou Zhang Jin-Shan Li 《Journal of Materials Science》2012,47(1):521-529
The kinetics of martensite decomposition in TC21 alloy was investigated at isothermal conditions in the temperature range
500–850 °C. The dilatometry technique was utilized to trace the transformation process for different aging temperatures. Within
the framework of the Avrami theory, the analysis of the experimental data was made by means of the Johnson–Mehl–Avrami (JMA)
equation. A very good correspondence between the calculated and the experimental results was found. The JMA kinetic parameters
obtained from different aging temperatures implied different mechanisms of the transformation. The α″ phase transforms to
α + α″ (rich) at 500 °C and the transformation is incomplete. Further increase of the temperature to 800 and 850 °C results
in directly transformation α″ →α + β. The mechanism of the transformation alters during the course of the transformation for
550, 600, 650, 700, and 750 °C. Moreover, The TTT diagram was constructed for the martensite decomposition in TC21 alloy based
on the dilatometry analysis and JMA theory, respectively. Good agreement between experimental and calculated TTT diagram is
observed. 相似文献
17.
Juan Dai Wei Long Zhongping Liang Fan Yang 《Drug development and industrial pharmacy》2018,44(1):89-98
Delivery of biomacromolecular drugs into the inner ear is challenging, mainly because of their inherent instability as well as physiological and anatomical barriers. Therefore, protein-friendly, hydrogel-based delivery systems following local administration are being developed for inner ear therapy. Herein, biodegradable poly(lactic-co-glycolic acid) (PLGA) nanoparticles (NPs) containing interferon α-2?b (IFN α-2?b) were loaded in chitosan/glycerophosphate (CS/GP)-based thermosensitive hydrogel for IFN delivery by intratympanic injection. The injectable hydrogel possessed a physiological pH and formed semi-solid gel at 37?°C, with good swelling and deswelling properties. The CS/GP hydrogel could slowly degrade as visualized by scanning electron microscopy (SEM). The presence of NPs in CS/GP gel largely influenced in vitro drug release. In the guinea pig cochlea, a 1.5- to 3-fold increase in the drug exposure time of NPs-CS/GP was found than those of the solution, NPs and IFN-loaded hydrogel. Most importantly, a prolonged residence time was attained without obvious histological changes in the inner ear. This biodegradable, injectable, and thermosensitive NPs-CS/GP system may allow longer delivery of protein drugs to the inner ear, thus may be a potential novel vehicle for inner ear therapy. 相似文献
18.
We have developed a procedure for the synthesis of phase-pure α- and β-Cu2V2O7. Thermal analysis and X-ray diffraction demonstrate that the β-phase (monoclinic structure) exists at low temperatures (stability
range 25–610°C), while α-Cu2V2O7 (orthorhombic structure) is stable in the range 610–704°C. The α-phase observed during cooling, in particular at room temperature,
is in a metastable state. The melting of the high-temperature phase γ-Cu2V2O7, which forms between 704 and 716°C, has the highest rate in the range 770–785°S and is accompanied by peritectic decomposition
and oxygen gas release. Subsequent cooling gives rise to four exothermic peaks, one of which (780.9°C) is attributable to
the crystallization of the peritectic melt, one (620.1°C) is due to the γ → α → β phase transformations of Cu2V2O7, and the other two arise from the crystallization of multicomponent low-melting-point eutectics containing α- and β-Cu2V2O7, CuVO3, and other compounds. 相似文献
19.
Chang-qing Li Bo Huang Gang Luo Chuan-zhi Zhang Ying Zhuang Yue Zhou 《Journal of materials science. Materials in medicine》2010,21(2):741-751
To construct a novel scaffold for nucleus pulposus (NP) tissue engineering, The porous type II collagen (CII)/hyaluronate
(HyA)–chondroitin-6-sulfate (6-CS) scaffold was prepared using 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide (EDC) and N-hydroxysuccinimide (NHS) cross-linking system. The physico-chemical properties and biocompatibility of CII/HyA–CS scaffolds
were evaluated. The results suggested CII/HyA–CS scaffolds have a highly porous structure (porosity: 94.8 ± 1.5%), high water-binding
capacity (79.2 ± 2.8%) and significantly improved mechanical stability by EDC/NHS crosslinking (denaturation temperature:
74.6 ± 1.8 and 58.1 ± 2.6°C, respectively, for the crosslinked scaffolds and the non-crosslinked; collagenase degradation
rate: 39.5 ± 3.4 and 63.5 ± 2.0%, respectively, for the crosslinked scaffolds and the non-crosslinked). The CII/HyA–CS scaffolds
also showed satisfactory cytocompatibility and histocompatibility as well as low immunogenicity. These results indicate CII/HyA–CS
scaffolds may be an alternative material for NP tissue engineering due to the similarity of its composition and physico-chemical
properties to those of the extracellular matrices (ECM) of native NP. 相似文献
20.
Mansur Ahmed Azdiar A. Gazder Dmytro G. Savvakin Orest M. Ivasishin Elena V. Pereloma 《Journal of Materials Science》2012,47(19):7013-7025
In the present study, two powders near-β Ti alloys having a nominal composition of Ti-5Al-5Mo-5V-XCr-1Fe (X = 1–2, wt%) were studied. The alloys were produced via the blended elemental powder metallurgy technique using hydrogenated Ti powder. Microstructure evolution and the distribution of the alloying elements between the phases were investigated after each step of thermo-mechanical processing (TMP). Microstructures were refined through the TMP in both alloys. Porosity was reduced with deformation at 1173 K (900 °C) in the β phase field. The β → α phase transformation occurred during soaking at 1023 K (750 °C) in the α + β phase field. Fragmentation of the continuous grain boundary α occurred because of the 40 % deformation at 1023 K (750 °C). Variation in the concentration of the alloying elements in each phase took place through the diffusion during soaking in the α + β phase field, e.g. exit of β-stabilisers from the α-phase. However, the α phase remained supersaturated with β stabilisers. Deformation had no influence on the distribution of the alloying elements. An addition of 1 % Cr content slightly affects the amount of the α phase formed and β grain size, but it has no noticeable effect on the distribution of the alloying elements between the phases. 相似文献