Experimental Study Of Bladder Cancer Selfmade Targeting Nano Ultrasound Contrast Agents Targeting Tumor-Bearing Mice

Objective: Homemade targeted bladder cancer BIU-87 cells Nano ultrasound contrast agent and verify the characteristic of tumor targeting in vivo.Methods: targeting nano-microbubble contrast agent were successfully prepared by mechanical vibration method and biotin-avidin bridges. twelve SPF BALB / c-nu male nude mice were randomly divided into two groups(experimental and control groups)which has been selected successfully transplanted bladder cancer cell line BIU-87 two weeks.Experimental group(n = 6; Weight: 22g-24g) caudal vein injection 200 ? L targeting peptide NYZL1(cyclic heptapeptide CSSPIGRHC,Cys-Ser-Ser-Pro-Ile-Gly-Arg-His-Cys) mediated nano-bubbles agent; the control group(n= 6; changes in body weight: 21.5g ± 24.5g) tail intravenous injection of 200?l ordinary nano-bubbles; interventional ultrasound is used for dynamic observation of tumor imaging effects in vivo(start developing time, the largest peak gray value, duration of contrast agent development time, decay half-time of contrast agent) and tumor molecular fluorescence imaging.Results: 1. Successfully prepared targeted BIU-87 ultrasound contrast agents, more than90% of the microbubbles particle size are between 500-700 nm. Homemade Nano ultrasound contrast agent is physically stable, milky white suspension apparent, uniform microbubbles particle size, great dispersion; sphericalat 400 * light microscope.2. Nano ultrasound microbubbles 220?mol / L is the best injection concentration, 200?L injection volume inject into nude mice lumpy via the tail vein, CEUS showed:microbubble contrast agents can image in the site of tumor after circulating in vivo experiment group began to appear hyperechoic point about 10 seconds later,quickly filling the entire tumor,and ultrasound gray gradually increased to the peak. In the control group, the tumor began to image about 13 seconds later and gradually reached a peak concentration, peak grayscale of the experimental group is about 19.76 ± 1.95 d B, with control group about 15.49 ± 1.85 d B, P = 0.003 <0.05, targeted microbubbles was significantly higher than ordinary nano-bubbles on average time of peak for imaging(P<0.05), with half-decay time significantly longer than ordinary microbubbles(P <0.05), therefore, targeted microbubble contrast agent can be highly specific bind tumor,long-lasting, and be proved to have targeting effect.3. Caudal vein injection cy7 near-infrared fluorescent probe modified bladder cancer targeting peptide CSSPIGRHC sequences four hours later, the imaging of tumor is strongest and kidney is visible,while other organs are unconspicuous.after 12 hours,transplantation tumor is no images, it further validates that polypeptide sequence CSSPIGRHC is targeted to bladder cancer BIU87.Conclusion: The self-made nano-bubble contrast agent targeted bladder cancer BIU-87 can combine with xenograft tumor-specific,it can detect high concentrations of tumor.NYZL1 mediated nano-bubbles capable of specifically binding bladder tumor, good targeting ability and can not easily be rid by the phagocytic system, therefore,it could be animportant small molecule carrier for diagnosis and precise treatment of bladder cancer providing a theoretical basis for early accurate diagnosis and treatment.