Effect of anesthesia on cognitive status and MMP-2 expression in rats.

OBJECTIVE: To investigate the effect of anesthesia on the cognitive status damage and MMP-2 expression in rats. METHODS: A total of 120 healthy rats were selected and randomly divided into the control group, CF3-CH(OCH2F)-CF3 (Sevoflurane) group and CF3-CH2-O-CHF-CF3 group (Sevoflurane) (n=40). After training for 3 d by the Morris water maze, the control group were injected with fentanyl for analgesia, the CF3-CH(OCH2F)-CF3 group and the CF3-CH2-O-CHF-CF3 group were anesthesia with CF3-CH (OCH2F)-CF3 and CF3-CH2-O-CHF-CF3 on the basis of fentanyl, then rats in three groups underwent open surgery and suture conventional incision. Morris water maze was used to measure the rats' cognitive ability in three groups on the 1st d, 3rd d, 5th d and 7th d, and the brain tissue MMP-2 expression was detected. RESULTS: After 1 d/7 d of the surgery, Morris water maze performance and MMP-2 expression were not significantly different among three groups (P>0.05); After 3 d/5 d of the surgery, compared with the control group, the Morris water maze test result was significantly worsened, MMP-2 expression levels were significantly increased (P<0.05); After 3 d/5 d of the surgery, compared with the CF3-CH2-O-CHF-CF3 group, Morris water maze test result of CF3-CH(OCH2F)-CF3 group was significantly worsened, MMP-2 expression levels were significantly increased (P<0.05). CONCLUSIONS: Anesthesia can cause some injury on cognitive status, different anesthetic drugs may cause different injury, and the cognitive status injury is related to the MMP-2 expression.

[Preparation of scopolamine hydrobromide nanoparticles-in-microsphere system].

This study is to prepare scopolamine hydrobromide nanoparticles-in-microsphere system (SH-NiMS) and evaluate its drug release characteristics in vitro. SH nanoparticles were prepared by ionic crosslinking method with tripolyphosphate (TPP) as crosslinker and chitosan as carrier. Orthogonal design was used to optimize the formulation of SH nanoparticles, which took the property of encapsulation efficiency and drug loading as evaluation parameters. With HPMC as carrier, adjusted the parameters of spray drying technique and sprayed the SH nanoparticles in microspheres encaposulated by HPMC was formed and which is called nanoparticles-in-microsphere system (NiMS). SH-NiMS appearances were observed by SEM, structure was obsearved by FT-IR and the release characteristics in vitro were evaluated. The optimized formulation of SH nanoparticles was TPP/CS 1:3 (w/w), HPMC 0.3%, SH 0.2%. The solution peristaltic speed of the spray drying technique was adjusted to 15%, and the temperature of inlet was 110 degrees C. The encapsulation product yeild, drug loading and particle sizes of SH-NiMS were 94.2%, 20.4%, and 1256.5 nm, respectively. The appearances and the structure of SH-NiMS were good. The preparation method of SH-NiMS is stable and reliable to use, which provide a new way to develop new dosage form.