To obtain a kind of convenient oral dosage form of protein, which can be fully absorbed and is efficient and safe, the thymosin-loaded PLA（polylactic acid） microspheres are prepared by the emulsification- solvent ev...To obtain a kind of convenient oral dosage form of protein, which can be fully absorbed and is efficient and safe, the thymosin-loaded PLA（polylactic acid） microspheres are prepared by the emulsification- solvent evaporation method and the orthogonal design is used to optimize the technology of preparation. The form of the medicament microspheres of thymosin are proved by differential thermal analysis （DTA）. The drug content is determined by the Lowry method, and the package ratio of medicament microspheres of thymosin and drug release in vitro are calculated. The results show that the average diameter and encapsulation efficiency of the product prepared according to the optimized formulation are 13. 8 μm and 80. 7%, respectively. The in vitro release behavior within 12 h can be described by the Higuchi equation with T1/2 = 295 rain. There are no significant changes in size distribution and residual drug contents after being stored at 25℃ and 40 ℃ for 90 d, respectively. Due to the fact that its thymosin content and package ratio meet the requirement, and its releasing half life is long, the thymosin-loaded PLA microsohere has a favorable application future.展开更多
To design an accelerated method to evaluate thymopentin release from PLGA microspheres in vitro. Microspheres were prepared by double emulsion technique, using poly（lactide-co-glycolide） （PLGA） as carrier. At high...To design an accelerated method to evaluate thymopentin release from PLGA microspheres in vitro. Microspheres were prepared by double emulsion technique, using poly（lactide-co-glycolide） （PLGA） as carrier. At higher medium temperature （45℃, 50℃ and 55℃）, an accelerated release testing in short time was studied and correlated with the conventional release （37℃） in vitro. The release in vitro of thymopentin from PLGA microspheres at 45 ℃, 50℃ and 55℃ was significantly accelerated （P 〈 0.05）. In particular, at 50℃, an accelerated release （30 h） of the hydrophilic peptide from the PLGA matrix was achieved and correlated well with the conventional release （30 d）. An accelerated release testing in vitro at higher temperature could be used to monitor thymopentin release from PLGA microspheres.展开更多
The aim of this study was to investigate the effects of polypeptides from Chlamys farreri （PCF） on immunoeytes or immunocytes treated with dexamethasone （DEX） in vitro. After incubating immunoeytes with 25 mg/L PC...The aim of this study was to investigate the effects of polypeptides from Chlamys farreri （PCF） on immunoeytes or immunocytes treated with dexamethasone （DEX） in vitro. After incubating immunoeytes with 25 mg/L PCF or/and DEX for a given time, the proliferative response of thymocytes and splenoeytes to ConA were measured bv MTF assay; the subpopulations of thymocytes and splenic T lymphoeytes was analyzed by flow cytomety; the cytotoxicity of natural killer cells was measured by Llactate dehydrogenase （LDH） assay; the phagocytosis of rat peritoneal macrophages was measured by Neutral red assay and the Bel-2 protein expression of macrophages was detected by imrnunocytoehemical stain. The proliferative ability of rat thymocytes and splenocytes induced with ConA was enhanced and the depression of lymphoproliferation caused by DEX was reversed by PCF. The percentages of mouse thymic L3 T4^- Lyt-2^- and Lyt-2^＋ subpopulations and splenic Lyt-2 ^＋ cells were decreased and the percentage of splenic L3 T4^ ＋ cells was increased by PCF. The NK cytotoxicity, phagocytosis of macraphages and Bcl-2 protein expression of macrophages were enhanced and the decrease of NK cytotoxicity and Bel-2 protein expression of maerophages caused by DEX were reversed by PCF. PCF could not only enhance the normal immunity function, but also reverse the imrnunosuppression induced by DEX.展开更多
文摘To obtain a kind of convenient oral dosage form of protein, which can be fully absorbed and is efficient and safe, the thymosin-loaded PLA（polylactic acid） microspheres are prepared by the emulsification- solvent evaporation method and the orthogonal design is used to optimize the technology of preparation. The form of the medicament microspheres of thymosin are proved by differential thermal analysis （DTA）. The drug content is determined by the Lowry method, and the package ratio of medicament microspheres of thymosin and drug release in vitro are calculated. The results show that the average diameter and encapsulation efficiency of the product prepared according to the optimized formulation are 13. 8 μm and 80. 7%, respectively. The in vitro release behavior within 12 h can be described by the Higuchi equation with T1/2 = 295 rain. There are no significant changes in size distribution and residual drug contents after being stored at 25℃ and 40 ℃ for 90 d, respectively. Due to the fact that its thymosin content and package ratio meet the requirement, and its releasing half life is long, the thymosin-loaded PLA microsohere has a favorable application future.
文摘To design an accelerated method to evaluate thymopentin release from PLGA microspheres in vitro. Microspheres were prepared by double emulsion technique, using poly（lactide-co-glycolide） （PLGA） as carrier. At higher medium temperature （45℃, 50℃ and 55℃）, an accelerated release testing in short time was studied and correlated with the conventional release （37℃） in vitro. The release in vitro of thymopentin from PLGA microspheres at 45 ℃, 50℃ and 55℃ was significantly accelerated （P 〈 0.05）. In particular, at 50℃, an accelerated release （30 h） of the hydrophilic peptide from the PLGA matrix was achieved and correlated well with the conventional release （30 d）. An accelerated release testing in vitro at higher temperature could be used to monitor thymopentin release from PLGA microspheres.
文摘The aim of this study was to investigate the effects of polypeptides from Chlamys farreri （PCF） on immunoeytes or immunocytes treated with dexamethasone （DEX） in vitro. After incubating immunoeytes with 25 mg/L PCF or/and DEX for a given time, the proliferative response of thymocytes and splenoeytes to ConA were measured bv MTF assay; the subpopulations of thymocytes and splenic T lymphoeytes was analyzed by flow cytomety; the cytotoxicity of natural killer cells was measured by Llactate dehydrogenase （LDH） assay; the phagocytosis of rat peritoneal macrophages was measured by Neutral red assay and the Bel-2 protein expression of macrophages was detected by imrnunocytoehemical stain. The proliferative ability of rat thymocytes and splenocytes induced with ConA was enhanced and the depression of lymphoproliferation caused by DEX was reversed by PCF. The percentages of mouse thymic L3 T4^- Lyt-2^- and Lyt-2^＋ subpopulations and splenic Lyt-2 ^＋ cells were decreased and the percentage of splenic L3 T4^ ＋ cells was increased by PCF. The NK cytotoxicity, phagocytosis of macraphages and Bcl-2 protein expression of macrophages were enhanced and the decrease of NK cytotoxicity and Bel-2 protein expression of maerophages caused by DEX were reversed by PCF. PCF could not only enhance the normal immunity function, but also reverse the imrnunosuppression induced by DEX.
