ABSTRACT
In recent years, non-viral gene vectors have attracted great attention for efficient gene delivery due to the advantages, including low toxicity, low immunogenicity and simple preparation. Polyethylenimine (PEI) is one of the typical non-viral gene carriers that have been widely utilized for gene delivery owing to its superior capabilities in gene compression and buffering capacity. This article discusses the processes of gene delivery and the barriers of PEI-based carrier during the gene delivery, such as low biocompatibility, cytotoxicity, lack of specific targeting and insufficient gene release, etc. Therefore, we summarize the multiple approaches for the modifications of PEI in terms of improved biocompatibility, degradability, specific targeting and buffering capacity. Furthermore, we also review on the recent impressive progresses of smart stimuli-responsive PEI carriers, including endogenous stimuli (pH, reactive oxygen species, glutathione, biomolecular, etc), exogenous stimuli (light, temperature, magnetic field, etc) and dual-responsive strategies, which might provide guidance for the development of more efficient and safer non-viral gene vectors.
ABSTRACT
OBJECTIVE@#To investigate the management of crossing vessels compression in laparoscopic pyeloplasty.@*METHODS@#From January 2016 to June 2018, a total of 21 patients who were admitted to Peking University People's Hospital with ureteropelvic junction obstruction (UPJO) associated with crossing vascular compression were reviewed. There were 15 males and 6 females who formed this group, with a mean age of (33.9±15.0) years. There were 4 cases of mild hydronephrosis, 12 cases of moderate hydronephrosis and 5 cases of severe hydronephrosis before operation. All the patients underwent laparoscopic pyeloplasty in our hospital, including 13 on the left and 8 on the right. Laparoscopic pyeloplasty (Anderson-Hynes) were performed in all the patients. Hem-o-lok suspension (14 cases in the suspension group) or translocation of the crossing vessels (7 cases in the translocation group) were used for the intraoperative management of the crossing vessels. Double J tubes were removed 8 weeks postoperatively. The patient demographic data were collected (including operation time, treatment time of crossing vessels, intraoperative blood loss, time of drainage tube removal after operation, and average length of hospital stay), postoperative outcomes were evaluated and the patients were followed up regularly.@*RESULTS@#In all the patients, the crossing vessels were successfully reserved, and none of them were ligated intra-operatively. Mean operative times were (202.2±57.0) min. The duration of intraoperative treatment of crossing vessels was (10.5±3.2) min, (6.1±2.0) min in the suspension group, and (13.7±5.2) min in the translocation group, respectively. Intraoperative blood loss was (47.8±25.6) mL, postoperative drainage time was (4.8±2.6) d, and length of hospital stay was (11.5±3.3) d. Postoperative slight urinary leakage occurred in 1 case. Preoperative pyelectasis of the affected side of all the patients was (3.4±1.7) cm, compared with postoperative pyelectasis of (1.9±1.3) cm. The difference was statistically significant (P<0.05). Postoperative follow-up of all the patients was carried out until December 2018. There was no significant difference in kidney size in all the patients before or after the operations, and hydronephrosis was alleviated compared with that before surgery.@*CONCLUSION@#For UPJO patients with crossing vascular compression, according to the location of the crossing vessels, Hem-o-lok suspension or vessel transposition can be adopted to relieve the crossing vascular compression and improve the success rate of the surgery.