131I-Labeled Silk Fibroin Microspheres for Radioembolic Therapy of Rat Hepatocellular Carcinoma.

Transarterial radioembolization (TARE) is a promising technology in hepatocellular carcinoma (HCC) therapy, which utilizes radionuclide-labeled microspheres to achieve arterial embolization and internal irradiation. However, the therapeutic effect of liver cancer can be affected by low radionuclide labeling rate and stability, as well as poor biocompatibility, and non-biodegradability of microspheres. Here, 131I-labeled silk fibroin microspheres (131I-SFMs) were developed as radioembolization material for effective TARE therapy against HCC. Silk fibroin rich in 10.03% of tyrosine was extracted from silkworm cocoons and then emulsified and genipin-crosslinked to prepare SFMs. SFMs show a good settlement rate, biodegradability, hemocompatibility, and low cytotoxicity. Afterward, 131I-SFMs were obtained by radiolabeling 131I onto the SFMs through the chloramine-T method. 131I-SFMs possess a high 131I labeling rate of over 84% and good radioactive stability and are thus conducive to internal radiotherapy. Significantly, 131I-SFMs with diameters around 11 µm were successfully radioembolized at the hepatic artery. 131I-SFMs were diffused in the liver, indicating the favorable biodistribution and biosafety in vivo. Based on the combination of embolization and local radiotherapy, the administration of 131I-SFMs shows a favorable inhibitive effect against the progression of HCC. Overall, the newly developed 131I-SFMs as radioembolization microspheres provide a promising application for effective TARE therapy against liver cancer.

Effects of tetramethylpyrazine phosphate on pancreatic islet microcirculation in SD rats.

PURPOSES: Abnormal islet microcirculation impetus the insulin production and accelerates progression of Type 1 and 2 diabetes. In this study, we investigated whether tetramethylpyrazine phosphate (TMPP), a vasoactive substance, could regulate the islet microcirculation and insulin concentration and improve glycaemia in SD rats. METHODS: SD rats were randomly divided into two groups, the control and TMPP groups. Each group was further divided into three subgroups according to the intravenous injection of either saline, 15 or 30% glucose. The non-radioactive microsphere technique was adopted to measure the organ blood flow. Nitric oxide synthase (NOS) blocker L-NAME was used to address whether NO was involved in mediating the vasoactive effects of TMPP. RESULTS: In the TMPP group, TMPP increased the PBF (pancreatic blood flow), IBF (islet blood flow), and fIBF (fraction of islet blood flow out of pancreatic blood flow) by 57, 76 and 47%, respectively, after 30% glucose infusion, compared with the control, indicating that TMPP could regulate islet microcirculation. Furthermore, TMPP induced a 66% elevation of IBF and 37% of fIBF in the 30% glucose subgroups than the 15% ones. In 30% glucose-treated subgroups, TMPP improved the blood glucose concentration by 10%, compared with the control (19.3 ± 0.64 vs 17.32 ± 0.56 mmol/l, P < 0.05), without influencing the insulin secretion. Blocking NO formation prevented the enhanced PBF and IBF, evoking by TMPP with 30% glucose. CONCLUSIONS: TMPP can regulate the pancreatic islet microcirculation and possess a hypoglycemia effect after glucose infusion through affecting the islet microcirculation.

Changes in Muscular Blood Flow Induced by Acupuncture in Rat Ischemic Hindlimb / 全日本鍼灸学会雑誌

[Objective] The effects of acupuncture on muscular blood flow, muscular weight, and muscular dynamics were investigated in the rat hindlimb with induced hypoemia. In addition, the optimal conditions for acupuncture in the model were investigated.<BR>[Methods] In male SD rats, the right femoral artery was cut, and a No. 20 40-mm stainless needle was inserted about 3-5 mm into the anterior tibial muscle of the ischemic hindlimb for acupuncture. During acupuncture, the needle was indwelled or electric current was passed, and various stimulations (5h/day, 1 h × 5 times/day, 15 min × 5 times/day, 1 h/day, and 15 min/day) were applied for 5 consecutive days. Seven days after cutting the artery, blood flow was measured by the radioactive microsphere method, and the degree of muscular atrophy was investigated by the weight ratio of the ischemic hindlimb to the contralateral healthy limb, and findings in the intact, hypoemia, hypoemia + indwelled needle, and hypoemia + various current groups were compared. In addition, the anterior tibial muscle was stained to observe the condition of muscular fibers.<BR>[Results and Discussion] In the ischemic group, muscular blood flow was decreased. In the hypoemia+current groups, blood flow was increased. In the groups that received electric current for a prolonged period, 5 h/day and 1 h ×5 times/day, the blood flow was increased but the muscular weight ratio was decreased. However, in the group that received stimulation for 15min×5 times/day, the muscular blood flow was markedly higher that those in the other groups, and the muscular weight ratio was not changed, showing that muscular atrophy did not occur. On staining, capillary neovascularization and VEGF production were greater than those in the hypoemia group, suggesting that these factors were closely involved in the increase in blood flow.