ABSTRACT
OBJECTIVE： To study the anti-inflammatory effect and its mechanism of the extract of Dcsmodium microphyllum， so as to provide experiment reference for further study of D. microphyllum. METHODS： Acute inflammatory model was established by xylene，glacial acetic acid and carrageenan. Using dexamethasone as positive control （0.005 g/kg）， inhibitory effects of intragastric different doses of the extract of D. microphyllum （50， 30， 15 g/kg） on xylene-induced ear swelling in normal mice and adrenalectomized mice， glacial acetic acid-induced permeability increasing of abdominal capillaries in normal mice， carrageenan- induced paw swelling in normal mice and adrenalectomized mice were investigated. The levels of MDA， SOD and NO in the inflammatory tissue of toes of adrenalectomized mice were detected in carrageenan-induced inflammation model. Blank group was set for control （ig. equal volumn of water）. RESULTS： Compared with blank group， ear swelling degree of normal mice and adrenalectomized mice were decreased significantly in D. microphyllum extract high-dose and medium-dose groups while inhibitory rate of ear swelling was increased significantly； the permeability of abdominal capillaries of normal mice was significantly decreased in D. microphyllum extract groups； the swelling degree of toes in normal mice of D. microphyllum extract high-dose and middle-dose groups and adrenalectomized mice were significantly decreased while inhibitory rate of toe swelling was increased significantly （P＜0.05 or P＜0.01）. The levels of MDA and NO in the toe inflammatory site of adrenalectomized mice were decreased significantly in D. microphyllum extract high-dose and medium-dose groups， while the level of SOD was increased significantly （P＜0.05）. CONCLUSIONS： D. microphyllum extract can inhibit acute inflammation in mice significantly. Its anti-inflammatory mechanism is associated with decreasing MDA and NO while increasing SOD levels， and the anti-inflammatory effect does not depend on the hypothalamus-pituitary-adrenal axis system.
ABSTRACT
BACKGROUND:Tissue-engineered bone scaffold fabricated by 3D-bioprinting technique has good controlability in morphology and structure. However, construction of tissue-engineered bone/cel growth factor complex and time-dose effect of sustained-release factors are needed to be further researched. OBJECTIVE:To fabricate a sustained-release composite of polylactic-co-glycolic acid (PLGA)/nano-hydroxyapatite (n-HA) scaffold carrying bone morphogenetic protein-2 (BMP-2) using 3D-bioprinting technique, and test the biological properties of the PLGA/n-HA scaffold carrying BMP-2 and the sustained-release properties, thereby to discuss its feasibility as the tissue-engineered bone scaffold composite. METHODS:Temperature-sensitive chitosan hydrogel was prepared using chitosan andβ-glycerophosphate to construct a sustained-release composite, chitosan nanoparticles carrying BMP-2 . 3D-bioprinting technique was utilized to fabricate the PLGA/n-HA scaffold carrying BMP-2. Biological features of the scaffold composite were tested, and time-dose effect of BMP-2 sustained-release was observed. RESULTS AND CONCLUSION:The average pore size of the scaffold-cytokine composite was (431.31±18.40)μm, and the porosity was (73.64±1.82)%. The cumulative release rate of BMP-2 from the scaffold-cytokine composite that effectively controled the burst release during 48 hours and 30 days were suitable for the physiological needs. In conclusion, the porosity, pore size, release property, degradation rate, and mechanical strength of the scaffold-cytokine composite al meet the biological requirements of tissue-engineered bone construction.