Biological properties study and animal experiment of polylactide/polytrimethylene carbonate blends membrane / 生物医学工程学杂志

Polylactide is a biodegradable and biocompatible biomaterial. Based on the PLA (Polylactide) membrane, we have produced a new PLA/PTMC (Polytrimethylene carbonate) blends membrane. The biological properties of this membrane were studied by cell toxicity experiment, acute toxicity experiment, skin irritant experiment, sensitization test, hemolytic test, micronucleus test and subcutaneous implantation test. The results demonstrated that the blends membrane has no toxicity and it does not cause skin irritation, hypersensitive reaction and hemolysis. The micronucleus ratio of the membrane is 1.3% +/- 1.0%, being less than 3%. The result of medullary micronucleus test was reported negative. The wounds were free from suppuration and necrosis after subcutaneous implantation in all periods. In the experimental application of this member to preventing adhesion after rabbit intestine operation, the membrane demonstrated good effect. In conclusion, PLA/PTMC blends membrane is a material with good biocompatibility.

Kinetics and related thermodynamics on the extraction of flavonoids from Fagopyrum tartarjcum / 中成药

AIM: To explore the kinetics and thermodynamics parameters in the extraction of flavonoids from Fagopyrum tartarjcum . METHODS: Rutin was adopted as marker substance to create a regression equation between Rutin concentration and absorbance by meaus of UV. RESULTS: According to Fick diffusion principle Ⅱ, extraction process was analysed to gain parameters, such as K, Ea, Y, t 1/2 , K ?. CONCLUSION: The method would be useful for the process design and the choice of operation condition to extract flavonoids from Fagopyrum tartarjcum.

Influence of the technology of supercritical CO_2 extraction on the separate rate of the extractives from fruits of Cnidium Monnieri(L.) Cuss / 中成药

AIM: To use secondary regression coherent design to explore the extraction parameters of fruits of Cnidiunm by supercritical CO_2 extraction. METHODS: Extraction pressure,extraction temperature,isolation pressure,isolation temperature Ⅰ and Ⅱ were viewed as factors. RESULTS: The best technological conditions were: extractive kettle pressure was 20 MPa,extractive kettle temperature was at 40(?C);separate kettle Ⅰ pressure was 15 MPa,separate kettle Ⅰ temperature was at 65(?C);separate kettle Ⅱ pressure was 5 MPa,separate ketle Ⅱ temperature was at 38(?C);CO_2 flow rate was 18 L/H,extractive time was 80 min. CONCLUSION: Under these conditions,the separate rate of the extractives from fruits of Cnidium Monnieri(L.) Cuss.could be(24.03%).Using secondary regression coherent design could naturally react the influence of the rule on the every factor to the goal function.