Objective To develop MSNs loaded with ICG and investigate its diagnostic value and photodynamic therapeutic value in the experimental pancreatic cancer. Methods ICG was loaded into MSNs to prepare the ICG/MSNs probe. The probe toxicity was evaluated by MTT assays. Near?infrared stereo fluores?cence microscope ( NISFM) was applied to investigate whether the ICG/MSNs would be uptaken by the human pancreatic cancer cells. After incubated with PBS, ICG (10μg/ml), MSNs or ICG/MSNs (10μg/ml ICG) for 24 h and treated with photodynamic therapy (PDT, (780±25) nm laser, 500 mW/cm2), the human pancreatic cancer cells survival rate was determined by MTT method. The human pancreatic cancer cells were implanted into nude mice to prepare subcutaneous tumor models. The distribution of ICG/MSNs in sub?cutaneous tumor models was studied with in vivo imaging system ( IVIS ) . With reference to the injection dose of ICG(0.5 mg/kg), the mice in PBS group, ICG group, ICG/MSNs group (4 mice per group) were injected via tail vein with 150μl PBS, ICG solution and ICG/MSNs solution, respectively. After treated by PDT for 48 h, the mice were observed by IVIS for 2 weeks using BLI to evaluate the therapeutic effect of PDT. NISFM was used to observe the fluorescence in tumor region. One?way analysis of variance was used to analyze the data. Results The diameter of ICG/MSNs was about 100 nm and it could be uptaken by human pancreatic cancer cells. After treated by PDT, the survival rates of human pancreatic cancer cells were (24?5±5.0)%, (81.2±1.6)%, (90.7±2.0)% and (93.4±1.7)% in ICG/MSNs group, ICG group, MSNs group and PBS group, respectively(F=212.289, P<0.05). ICG/MSNs group showed better therapeutic effect than ICG group( P<0.05) . After 12 d treated by PDT, the tumor did not recur or grow in ICG/MSNs group, but grew obviously in ICG group and PBS group. The BLI of tumor area in PBS group, ICG group and ICG/MSNs group were (61.2±7.7)×108, (56.7±9.0)×108 and (2.4±1.5)×108, respectively(F=67?098, P<0.05) . And the difference between ICG/MSNs and ICG group was statistically significant ( P<0.05) . Meanwhile, the NISFM showed clearly the tumor location with ICG/MSNs. Conclusions ICG/MSNs have good biocompatibility, good PDT effect on pancreatic cancer cells and pancreatic cancer xeno?grafts. Near?infrared fluorescence imaging with ICG/MSNs could delineate the tumor location.

Since the concept of molecular imaging was put forward in 1999,optical molecular imaging techniques have been widely applied in the field of biomedical and clinical research.Its unique application value is especially shown in hepatobiliary surgery,such as in liver tumor imaging,anatomical liver resection,liver transplant angiography,cholangiography,and bile or pancreatic leakage prevention.Optical molecular imaging technique "lights up" targeted areas in surgical operations and provides convenience in carrying out precision operation.This paper reviewed the advantages of optical molecular imaging technology in clinical research and discussed its limitations in translational surgery,and put forward possible directions in improvement for the future.

Objective: To investigate the clinical application of indocyanine green fluorescence imaging in open hepatectomy. Methods: A total of forty-five patients who underwent liver resection in Department of Hepatobiliary Surgery, Affiliated Hospital of Southwest Medical University from July 2017 to December 2018 were included in this prospective study. There were 26 males and 19 females, aged between 29 to 74 (51±10) years. Indocyanine green was injected intravenously 72~96 hours prior to surgery in all these patients. An intraoperative fluorescence imaging system was used to locate and remove the tumor, the liver parenchymal transection planes and surgical margins were detected by fluorescence again after tumor resection. The fluorescence profiles of the tumor specimens in relation to the tumor differentiation were analyzed. Results: Indocyanine green fluorescence imaging was performed in 45 patients. A total of 66 lesions were detected by preoperative CT (or MRI), abdominal ultrasound and intraoperative fluorescence imaging. After excision of the primary liver cancer, the surgical margins of the remnant liver stumps and fluorescence in the excised liver specimens were studied. Thirteen small lesions were found in 10 patients, most of which were located at the surgical margin, and the smallest tumors detected were less than 5 mm in diameter. Five venous cancer emboli were found in 5 patients, 3 of which were not detected by preoperative imaging examinations. The fluorescence profile images of the excised hepatocellular carcinoma specimens showed homogeneous fluorescence in most highly differentiated hepatocellular carcinoma, and partial fluorescence or ring fluorescence in moderately differentiated hepatocellular carcinoma. Conclusion Indocyanine green fluorescence imaging technology can identify liver surface lesions, as well as detect small residual lesions at the cutting edge and venous thrombus, which improves the efficiency of hepatocellular carcinoma resection.