University of Macau / Institute of Chinese Medical Sciences

University of Macau / Institute of Chinese Medical Sciences

University of Macau / Institute of Chinese Medical Sciences

Surgical resection is the best option for both liver and kidney cancers, which providing the long term survival. However intraoperative blood loss can be a significant challenge, and is clearly associated with morbidity and mortality. Radiofrequency ablation (RFA) precoagulation has been introduced into liver and kidney surgery. Promising results have already achieved in reduction of intraoperative blood loss. In this thesis, a detailed explanation on precoagulation by RFA has been given. Our group developed a novel bipolar multi-array RFA device ??? InLine (ILRFA). In this thesis, we have investigated the performance in a variety of fields. In the study of ILRFA-assisted laparoscopic liver resection, ILRFA was easily employed through a hand port and achieved significant decrease of blood loss compared to control group (p < 0.05). In the liver trauma study, ILRFA produced a 63.88% reduction of blood loss in peripheral injury and 53.57% in central injury respectively. In postoperative evaluation of ILRFA-assisted liver resection, animals underwent an uneventful recovery, no complications occurred. Histological examination revealed a typical post RFA evolution. In ILRFA-assisted partial nephrectomy, the mean intraoperative blood loss 35 ?? 7 ml in the ILRFA and 152 ?? 94 ml in the control, a 77.0% reduction (P = 0.024). The mean blood loss per centimetre resection area was 2.09 ?? 1.41 ml/cm2 in the ILRFA compared with 12.79 ?? 1.68 ml/cm2 in controls, the reduction was 79.0% (P = 0.019). In ILRFAassisted laparoscopic partial nephrectomy, the mean intraoperative blood loss was 32 ?? 15 ml in the ILRFA and 187 ?? 69 ml in the control group, a 77.0% reduction (P = 0.043). The mean blood loss per centimetre resection area was 2.27 ?? 0.95 ml/cm2 in the ILRFA compared with 26.46 ?? 8.81 ml/cm2 in controls, the reduction was 79.0% (P = 0.047). In the renal trauma experiment, ILRFA also achieved promising results in haemostasis. We believe that ILRFA is a useful device which may help in the treatment of patients with liver and kidney illness.

Surgical resection is the best option for both liver and kidney cancers, which providing the long term survival. However intraoperative blood loss can be a significant challenge, and is clearly associated with morbidity and mortality. Radiofrequency ablation (RFA) precoagulation has been introduced into liver and kidney surgery. Promising results have already achieved in reduction of intraoperative blood loss. In this thesis, a detailed explanation on precoagulation by RFA has been given. Our group developed a novel bipolar multi-array RFA device ??? InLine (ILRFA). In this thesis, we have investigated the performance in a variety of fields. In the study of ILRFA-assisted laparoscopic liver resection, ILRFA was easily employed through a hand port and achieved significant decrease of blood loss compared to control group (p < 0.05). In the liver trauma study, ILRFA produced a 63.88% reduction of blood loss in peripheral injury and 53.57% in central injury respectively. In postoperative evaluation of ILRFA-assisted liver resection, animals underwent an uneventful recovery, no complications occurred. Histological examination revealed a typical post RFA evolution. In ILRFA-assisted partial nephrectomy, the mean intraoperative blood loss 35 ?? 7 ml in the ILRFA and 152 ?? 94 ml in the control, a 77.0% reduction (P = 0.024). The mean blood loss per centimetre resection area was 2.09 ?? 1.41 ml/cm2 in the ILRFA compared with 12.79 ?? 1.68 ml/cm2 in controls, the reduction was 79.0% (P = 0.019). In ILRFAassisted laparoscopic partial nephrectomy, the mean intraoperative blood loss was 32 ?? 15 ml in the ILRFA and 187 ?? 69 ml in the control group, a 77.0% reduction (P = 0.043). The mean blood loss per centimetre resection area was 2.27 ?? 0.95 ml/cm2 in the ILRFA compared with 26.46 ?? 8.81 ml/cm2 in controls, the reduction was 79.0% (P = 0.047). In the renal trauma experiment, ILRFA also achieved promising results in haemostasis. We believe that ILRFA is a useful device which may help in the treatment of patients with liver and kidney illness.

University of Macau / Institute of Chinese Medical Sciences

In the growing landscape of innovative non-viral delivery vehicles, polymeric and lipid nanoparticles remain at the forefront for their versatility in encapsulating a variety of therapeutic payloads. This thesis investigates their potential for facilitating the transport of nucleic acid components into cells, with a focus on targeted delivery to the liver and brain. To achieve this, we address key considerations including the composition of the delivery vector, the nature of the therapeutic cargo, and the chosen delivery route. The challenge of targeted delivery to specific organs or cell types, i.e. hepatocytes or neurons, is addressed through rational design and development of libraries of nanoparticulate systems tailored for nucleic acid therapeutics. Although liver gene editing using non-viral systems has been extensively studied, oral delivery for liver targeting remains challenging due to the mucosal barrier. To that end, we explore intraduodenal delivery as a strategy to bypass the mucosal barrier and target the liver. Furthermore, insights from collaborative research with the Mao lab at Johns Hopkins University reveal that tuning the composition of lipid nanoparticles (LNPs) can influence their preferential targeting of specific cell types. Leveraging this, we employed an in vitro library screening and machine learning approach to identify populations of LNPs capable of preferentially transfecting hepatocytes. The efficacy of these LNPs in liver gene editing is then evaluated through “cluster-mode” screening in vivo, and therapeutic efficacy was demonstrated using a proof-of-concept in vivo model for PCSK9 and ANGPTL3 knockdown, resulting in 27% serum cholesterol knockdown. In addition to liver-targeted gene delivery, this thesis also investigates the potential of polymeric and lipid nanoparticles for delivering nucleic acid therapeutics to the brain. However, overcoming the blood-brain barrier (BBB) is crucial for systemic delivery to the brain. To circumvent the BBB, we explored two methods: intracranial injection and theranostic ultrasound (THUS)-mediated temporary opening of the BBB. While intracranial injection achieves localized gene editing, THUS offers a non-invasive approach for transient and widespread BBB opening. Utilizing the previously validated in vitro screening and machine learning approaches for chitosan-grafted bPEI (CS-PEI) and lipid nanoparticle (LNP) carriers with tunable compositions, we assessed their efficacy in systemic gene delivery to the brain, and specifically their capability in preferentially transfecting neuronal cells over hepatocytes. Subsequently, we validated their efficiency via intracranial administration using the Ai14 reporter mouse model and observed up to 20% gene editing of the targeted cross-sectional area of the brain hemisphere using the top-performing cluster. Through comprehensive investigations into both brain and liver gene delivery, this thesis aims to contribute to the advancement of non-viral nanoparticle-based gene therapy strategies for treating a range of cholestatic liver diseases and hereditary neurodegenerative diseases.

Finally, the hepatoprotection of the 50%EtWZ was evaluated using rat model. The results indicated that the 50%EtWZ possessed potent hepatoprotective activities. The protective effect of the extract against hepatotoxicity induced by long-term treatment with ethanol might be attributed to its inhibitory action on oxidative stress. Although multiple factors could be involved in the inhibition of oxidative injury in the liver, the inhibition of CYP2E1 pathway and the enhanced GSH-related antioxidant capacity might be responsible for the protective effect. In addition, the 50%EtWZ also produced anti-inflammatory effect partly by interfering Toll-Like-Receptor-4 (TLR-4)-mediated signal pathway and reducing the production of Tumor Necrosis Factor-alpha (INF-alpha) in Kupffer cells during long-term ethanol exposure. / First, in order to determine which kind of extract possesses the strongest hepatoprotective effect on ethanol-induced cytotoxicity, various extracts were screened for cytochrome P450 2E1 isoenzyme (CYP2E1) inhibitory activity using the fluorogenic CYP2E1 substrate and HepG2 cells overexpressing human CYP2E1. The results showed that all extracts (aqueous, 50% ethanol, and 90% ethanol) of WZ produced inhibitory effect on CYP2E1. The 50% ethanol extract of WZ (50%EtWZ) displayed a stronger CYP2E1 inhibition than the aqueous and 90% ethanol extracts. The aqueous extract and 50%EtWZ showed protective effect against ethanol-induced cytotoxicity at concentrations equivalent to 100 and 1000 mug raw herb/ml. At the same concentration of 100 1.1g/ml, the 50%EtWZ exhibited a more potent protective effect. Higher degree of cytotoxicity was found in the 90% ethanol extract of WZ. Thus, 50%EtWZ was chosen for further study. / In summary, all data suggest that the inhibition of CYP2E1 pathway and the inhibition of oxidative stress by the 50%EtWZ, together with the anti-inflammatory effect on Kupffer cells, may contribute to its hepatoprotection against chronic ethanol-induced liver injury. / Second, the chemical components of the 50%EtWZ were analyzed by chromatographic fingerprints. The fingerprint revealed six hepatoprotective compounds including schisandrin B, schisandrin, deoxyschisandrin, betaine, hyperin, and quercitrin in the formula. / Third, the protective mechanism of the 50%EtWZ was investigated in E47 cells model. The 50%EtWZ protected against CYP2E1-dependent toxicity and oxidative stress induced by ethanol. The mechanism of protection involved the decrease of reactive oxygen species production and the inhibition of lipid peroxidation. The hepataprotection was associated with the maintenance of mitochondrial GSH. Pre-treating E47 cells with the 50%EtWZ significantly inhibited the expression of CYP2E1. Therefore, the protective effect of the 50%EtWZ was most likely attributed to its antioxidant activities and the inhibition of CYP2E1. In addition, the 50%EtWZ prevented ethanol-induced apoptosis and protected against oxidative damage to mitochondria which are critical for maintenance of cell viability. / Wu-Zi-Yan-Zong-Wan (WZ), a traditional medicinal formula, is used for treatment of male sexual dysfunctions. In this study, the hepatoprotection afforded by Wu-Zi-Yan-Zong-Wan treatment and its biochemical mechanism involved against chronic alcohol-induced injury were investigated. / Chen, Mengli. / "May 2008." / Adviser: Che Chun Tao. / Source: Dissertation Abstracts International, Volume: 70-03, Section: B, page: 1609. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2008. / Includes bibliographical references (p. 157-179). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstracts in English and Chinese. / School code: 1307.

University of Macau / Institute of Chinese Medical Sciences