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Traditional medical device sterilization processes are mature, but there are constraints when using on medical devices by new materials. With increasing environmental concerns, using of ethylene oxide sterilization has been limited by global environmental protection administrations. Exploring new sterilization methods for medical devices is urgently needed. This paper reviews the supercritical carbon dioxide sterilization technology by arranging the exploratory work of industry researchers. In the paper, we introduce the theory of supercritical carbon dioxide sterilization technology, microbial inactivation ability, material influence research and sterilization equipment. Then we discuss the concerns and possibilities of the technology applied to the medical device industry basing on the good manufacturing practices.
Subject(s)
Carbon Dioxide , SterilizationABSTRACT
BACKGROUND: In recent years, there have been many studies on the use of supercritical fluids for biological material treatment in countries outside China. However, little is reported on application of supercritical fluids to bone tissue extraction, in particular in China. OBJECTIVE: To evaluate the effectiveness of supercritical carbon dioxide extraction technology in the treatment of porcine femur cancellous bone and its effect on bone biological properties. METHODS: Porcine femoral bone blocks that were subjected to supercritical carbon dioxide extraction (study group) or not (control group) were prepared to determine bone mineral density, microstructure, maximum compressive strength, elastic modulus, bone tissue composition, collagen content and perform histological analysis. Bone marrow mesenchymal stem cells (BMSCs) were inoculated into two groups of bone blocks, and cultured for 1 day. The microporous structure of trabecular bone and cell adhesion and growth in bone material-cell composite were observed by scanning electron microscopy. The two groups of bone blocks were implanted subcutaneously in SD rats. The inflammatory reaction of subcutaneous tissue was observed histologically at 1, 2 and 4 weeks after surgery. The experimental protocol had been approved by the Animal Ethics Committee of Chinese PLA General Hospital, China. RESULTS AND CONCLUSION: There were no significant differences in pore size, bone mineral density, maximum compressive strength, elastic modulus and collagen content between the study and control groups (P>0.05). Scanning electron microscopy showed that in the control group, the material pores had poor connectivity and there was soft tissue residue; in the study group, material pores were connected to each other and the structure was intact. Fourier transform infrared spectroscopy and X-ray diffraction analysis showed that the two groups of bone tissue materials had similar absorption and diffraction peaks. Thermogravimetric analysis showed that supercritical carbon dioxide extraction could reduce water content in bone tissue. Hematoxylin-eosin staining showed that there were no soft tissue residues in the bone, and the cell residues in the bone pit were significantly reduced in the study group, while soft tissue and cell residues were observed in the control group. Sirius red staining and modified Masson staining showed that the structure of bone collagen in the study group was intact, the cytoplasmic components reduced, and the cytoplasmic components in the control group remained significantly. Scanning electron microscopy showed that there was no obvious cell adhesion in the control group, but cell adhesion growth was obvious in the study group. Perivascular inflammatory response in the bone tissue implantation region was obviously weaker in the study group than in the study group. These results suggest that supercritical carbon dioxide extraction technology is an effective and environment-friendly bone tissue processing technology. It can effectively remove porcine cancellous bone cells and soft tissue without affecting its collagen structure and content and mechanical properties, retaining intact bone pore structure, increasing cell adhesion and growth, and effectively reducing inflammatory rejection.
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Luffa cylindrica (LC) is a very fast-growing climber and its fruit have been considered as agricultural wastes. We conducted to check the comparative qualities of ethanol solvent extraction (LCE) and supercritical carbon dioxide extraction (LCS) of L. cylindrica fruit and seed. LCS had higher antioxidant and polyphenol contents than LCE. LCS were significantly increased peroxisome proliferator-activated receptor (PPAR)-a and involucrin expression as epidermal differentiation marker in 3D skin equivalent model. LCS also showed antimicrobial activity against Staphylococcus aureus, a causative bacteria in atopic dermatitis. In addition, LCS inhibited the adipocyte differentiation of 3T3-L1 cells. When treated with the extract at a concentration of 100 µg/mL, the Wnt/β-catenin pathway reporter luciferase activity of HEK 293-TOP cells was increased approximately by 2-folds compared to that of the untreated control group. These results indicate that L. cylindrica supercritical carbon dioxide extract may serve as a cosmeceutical for improving skin barrier function and the treatment of obesity.
Subject(s)
3T3-L1 Cells , Adipocytes , Bacteria , Carbon Dioxide , Carbon , Dermatitis, Atopic , Ethanol , Fruit , Luciferases , Luffa , Obesity , Peroxisomes , Skin , Staphylococcus aureusABSTRACT
Objective To research the extraction conditions of cinnamon polyphenols with defatted cinnamon bark powder. Methods Cinnamon bark powder was extracted by supercritical carbon dioxide extraction to de-fat firstly and then the effects of extraction time, ethanol concentration, ratio of feed to liquid, and extraction temperature on the extraction ratio of polyphenols were investigated in detail. Results The result shows that the optimum extraction conditions of cinnamon polyphenols from the defatted cinnamon bark powder are: extraction time 2 h, ethanol concentration 55%, feed liquid ratio 1:8, and temperature 60 ℃. Under the above conditions, the extracted ratio of the polyphenols from the defatted cinnamon bark powder went up to 106.4 mg/g and the yield of cinnamon bark extract went up to 20.7%. The content of polyphenols in the dry extract was 51.4%, which was much higher than that from the original cinnamon powder while the content of coumarin of the extract was 104 μg/g. Conclusion The defatting of cinnamon powder by supercritical carbon dioxide extraction in advance can greatly increase the yield of cinnamon polyphenols and reduce the content of coumarin in the cinnamon bark extract.
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A novel method was established for the qualitative and quantitative determination of fatty acids in Channel Catfish muscle by gas chromatography-electron ionization-mass spectrometry (GC-EI-MS) after supercritical carbon dioxide fluid extraction (SFE-CO_2). The extraction parameters for the methodology were optimized). The optimal conditions were extraction pressure of 25 MPa at 45 ℃ and extraction time of 100 min at the rate of carbon dioxide 30 L/h. The fatty acids in the muscle oil were derived by boron-trifluoride method). The saponification time was 10 min, and the esterication time was 20 min. The obtained fatty acid methylesters were separated by gas chromatography using a HP-Innowax capillary column, and were detected by electron) ionization) mass spectrometry. Full scan mode and SIM mode were used for the qualitative and quantitative analysis), respectively. In the SIM mode, saturated fatty acids were determined with m/z 74, mono-unsaturated) fatty acids were determined with m/z 55, double-unsaturated fatty acids were determined with m/z 67, and polyunsaturated fatty acids were determined with m/z 79. The detection limits of 14 fatty acids were 2.2-20.0 μg/L(S/N=3)), and the quantitative limits were 7.39-59.85 μg/L(S/N=10). The recoveries fell in the range from 90.0% to 111.2%(n=4), and the relative standard deviation was between) 2.0% and 5.9%. This effective, sensitive and reproducible method can be used for the determination of fatty acids in Channel Catfish muscle sample.
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Objective:To find out the coefficients of garlic oil by Supercritical Fluid Extraction (SFE). Methods: Cutting, squeezing fermentation and fermentation and ethanol extraction of garlic were respectively as pretreatments and then the use of supercritical carbon dioxide as an extraction and given garlic oil was analysed by means of IR. Result: Garlic oil can be directly extracted by SFE and its best operation condition was under the pressure of 15 MPa and at 40 ?C extractability of garlic oil was up to 44.57% . Conclusion: Fermentation and ethanol extraction method is a best one for garlic oil obtained.
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AIM:To study the extraction of Schisandra Chinensis (Turcz) using supercritical carbon dioxide as extracting ageat. METHODS: The study was carried out through orthogonal test design,the content of schizandrin from Schisandra Chinensis (Turcz) was selected by 3 influencing factors, extract temperature, extract pressure and separation temperature. RESULTS:The optimal condition for the extraction as A3B2C1 Schisandra Chinensis (Turcz) was extracted by supercritical carbon dioxide, extract pressure was 25MPa, extract temperature was 50?C, separation was 7 MPa, separate temperature was 60?C, extract time was 2.5h and runing amount of CO2 was 15kg?h -1. CONCLUSION:It is feasible that supercritical carbon dioxide is used in the preparation of Schisandra Chinensis (Turcz).