ABSTRACT
Objective To study the effects about rhizoma drynariae poly (lactic-co-glycolic acid) (DR-PLGA) /Calcium phosphate cement (CPC) composite scaffold on treating rabbit femoral bone defect.Methods Eight Newzealand rabbits were randomly divided into experiment group(n =4) and control group (n =4).The preparation of rabbit femoral bone defect model,separately implanted DR-PLGA/CPC scaffold and PLGA/CPC scaffold.After 4,8 weeks,we took out the materials,observed with X-ray,gross anatomy,histology observation to evaluate the osteogenetic activity,the effect of accelerating the healing of bone defect.Resuits At the 4th week and 8th week after implantation,the effect of promoting fracture healing and osteogenic activity of the experiment group were greater than those in the control group.Conclusions DR-PLGA combined with CPC could induce new bone formation,promote the healing of rabbit femoral defect.
ABSTRACT
BACKGROUND:Microcapsules is one of the main directions of targeted therapeutic dosing system. With a size of several microns to several hundred microns, it can be used for injection, oral, arterial administration and local treatment of targeted organs and other treatment approaches. OBJECTIVE: To prepare rhizoma drynariae total flavonoids/polylactic-co-glycolic acid microcapsules and optimize the preparation conditions. METHODS: The rhizoma drynariae total flavonoids/polylactic-co-glycolic acid microcapsules was prepared by ultrasonic emulsification. The effect of the mass concentration (60, 100, 140, 180 g/L), stirring speed (50, 1 000, 2 000, 4 000 r/minutes), colostrum emulsification time (2, 4, 6, 8 minutes), colostrum water oil ratio (1:5, 1:10, 1:15, 1:20) of rhizoma drynariae total flavonoids/polylactic-co-glycolic acid microcapsules on gross morphology, particle size distribution width and total flavonoids encapsulation efficiency of microcapsules was univariately analyzed. The rhizoma drynariae total flavonoids/polylactic-co-glycolic acid microcapsules with smaler particle size, uniform dispersion and higher encapsulation efficiency was filtered out. RESULTS AND CONCLUSION: The optimum process parameters were as folows: 140 g/L polylactic acid-glycolic acid solution, the stirring speed of 2 000 r/min, the colostrum emulsification time of 6 minutes, and the colostrum water-oil ratio of 1:15. The microcapsules prepared in the optimized process displayed a uniform distribution and its average particle size was (789.8±712.3) nm, which distributed relative narrowly and basicaly less than 5 μm. Microcapsules presented round, with a regular edge under scanning electron microscope. The average encapsulation efficiency was 47.72%.