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BACKGROUND: Polyvinyl alcohol (PVA) has similar water content as human tissues, good biocompatibility and high mechanical strength, thereby being utilized as tissue-engineered matrix material. However, the modification in cellular affinity benefits the function as tissue regeneration scaffold materials. OBJECTIVE: To prepare chitosan (CS) / PVA composite scaffold and explore the feasibility of serving as a scaffold for tissue engineering. METHODS: Scaffolds of CS/PVA was fabricated by blending PVA-124 with various amounts of CS using film forming, particle forming, and free-drying methods. Water content, light transmittance, and swelling ratio were tested. Scanning electron microscope was used to observe the configuration of the cress section. RESULTS AND CONCLUSION: A total of 7 different proportional scaffolds were obtained with different PVA and CS dosage. The composite film showed light transmittance between 70%-80%, high water content between 121.2%-162.5% and swelling ratio between 60.3%-133.7%.Composita particle and sponge obtained water content between 82.0%-461.2% and 280.8%-1 939.0%. Composite scaffold with the amount ratio of PVA 0.75 g/CS 0.15 g exhibited the best performance. Scanning electron microscope showed that at a mass ratio of PVA 0.75 g/CS 0.15 g, the scaffold prepared by freeze-drying method had regular, tluffy inner structure, with good mechanics and high water content.
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Objective To fabricate a novel polyvinyl alcohol (PVA)-chitosan(Cs)-collagen (Col) composite material and to confirm the feasibility of its application as a scaffold in tissue engineering.Methods PVA was blended with chitosan and collagen.The water content,swelling ratio,and tensile strength of the scaffolds were tested.SEM was used to observe the histological modality of the cross section.Results Scaffolds which al'e composite with different molecular weight and different amount of Cs and Collagen ale made,with water content ranging from 60.15% to 72.50% and swelling ratio being from 185.33% to 317.57%.The tensile strength of the composite material is 5.70MPa.The inner modality and structure of the scaffolds varied as the proportion of the chemical components changed.Conclusion PVA-Cs-Col scaffolds have high water content and proper swelling ratio and ale rich in porous structure.When the blending proportion is Cs:PVA:COI=30:15:0.20,the scaffold performs best,which shows to be a suitable structure for tissue engineering scaffold.
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Objective To study the effect of procyanidin on neural cell apoptosis and the expression of Caspase-3 of cerebral ische-mia reperfusion(I/R) injury in rats. Methods 40 rats were randomly divided into 4 groups, which were sham operated group, I/R group, low dose procyanidin treated group and high dose procyanidin treated group. The focal middle cerebral artery occlusion (MCAO) model was made by suture-occluded method. After MCAO for 90min following 24h of reperfusion, neural cell apoptosis and the expression of caspase-3 was investigated with TUNEL and immunohistochemistry. HE staining and Trc staining was also used. Result Compared with sham opera-ted group, neural cell apoptosis rate and the expression of caspase-3 were increased at the 24th hour of reperfusion in the ischemic territory(P < 0.05) . Compared with I/R group, low and high dose procyanidin treated group reduced expression of caspase-3 and neural cell apopto-sis rate in a dose-dependent manor (P <0.05). The change of ischemic impairment in procyanidin treated group was less than that of I/R group, and the change of high dose procyanidin treated group was less than that of low dose procyanidin treated group. Compared with that of I/R group, cerebral infarction volume of procyanidin treated group was decreased in a dose-dependent manor (P < 0.05). Conclusion Procyanidin may reduce cerebral ischemia-reperfusion injure by reducing expression of caspase-3 and neural cell apoptosis.
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BACKGROUND:Polyvinyl alcohol(PVA)has similar water content as human tissues,good biocompatibility and high mechanical strength,thereby being utilized as tissue-engineered matrix material.However,the modification in cellular affinity benefits the function as tissue regeneration scaffold materials.OBJECTIVE:To prepare chitosan(CS)/PVA composite scaffold and explore the feasibility of serving as a scaffold for tissue engineering.METHODS:Scaffolds of CS/PVA was fabricated by blending PVA-124 with various amounts of CS using film forming,particle forming,and free-drying methods.Water content,light transmittance,and swelling ratio were tested.Scanning electron microscope was used to observe the configuration of the cross section.RESULTS AND CONCLUSION:A total of 7 different proportional scaffolds were obtained with different PVA and CS dosage.The composite film showed light transmittance between 70%-80%,high water content between 121.2%-162.5% and swelling ratio between 60.3%-133.7%.Composite particle and sponge obtained water content between 82.0%-461.2% and 280.8%-1 939.0%.Composite scaffold with the amount ratio of PVA 0.75 g/CS 0.15 g exhibited the best performance.Scanning electron microscope showed that at a mass ratio of PVA 0.75 g/CS 0.15 g,the scaffold prepared by freeze-drying method had regular,fluffy inner structure,with good mechanics and high water content.
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AIM: Based on the water-solubility of polyethylene glycol (PEG) with different relative molecular weight (RMW) and sodium alginate, we investigated the porous structure and property of calcium alginate scaffold with different RMW and dosages of PEG, which was used as porogenic agent. METHODS: The experiment was carried out in the Key Laboratory of Biomedical Engineering and Biomaterials, Jinan University from March 2006 to September 2007.①PEG at different RMWs (Mw=2 000, 4 000, 6 000, 8 000, 10 000, 20 000, 35 000) and different dosages (mass fraction=0, 0.01, 0.02, 0.03, 0.04, 0.05, 0.06) were added into sodium alginate solution at 0.02 mass fraction. Then alginate was crosslinked, solidified and molded into indiscerptible film and graininess through Ca2+. PEG was dissolved by water. Therefore, a mass of porous structures could be formed in alginate.②Water content and swelling ratio of alginate was tested. Scanning electron microscope was used to observe the porous configuration. RESULTS: ①Porous alginate scaffold could be obtained through PEG and it exhibited good intensity and toughness, with water content reaching 92%. The scaffold could be formed into film and graininess.②Scanning electron microscope results revealed that the distribution of porous structure was uniformed. The aperture was 43.75 ?m-2.8 mm, and could be controlled by PEG's RMW and dosage. Inflated and uniform aperture structure was harvested when RMW of PEG was 4 000 and 6 000. CONCLUSION: Porous alginate structure can be obtained through regulating PEG's RMW and dosage. High water content and porosity of alginate scaffold material can be used in cell culture of tissue engineering and used as controlled release matrix of bio-active component.