Surprising lack of liposome-induced complement activation by artificial 1,3-diamidophospholipids in vitro.

Cardio-vascular diseases are the main cause of death, emphasizing the need to improve patient treatment and survival. One therapeutic approach is a liposome-based drug carrier system specifically targeting constricted arteries. The recently discovered mechano-sensitive liposomes use hemodynamic shear-stress differences between healthy and constricted blood vessels as trigger for drug release. Liposomes are promising delivery containers but are being recognized as foreign by the immune system. Complement activation as essential factor of the recognition leads to adverse effects. Here, we tested complement activation by liposomes formulated from the artificial phospholipid Pad-PC-Pad in vitro. Surprisingly no complement activation was detected in human sera and porcine plasma. In in vivo experiments with three pigs, neither anaphylactic reactions nor other significant hemodynamic changes were observed even at comparably high liposome doses. The pilot study holds promise for an absence of complement-mediated adverse effects of Pad-PC-Pad liposomes in human. FROM THE CLINICAL EDITOR: A lot of research has been done on new treatment for cardiovascular diseases. Liposome-based carrier systems have also shown promises. In this article, the authors studied the potential risks of complement activation by liposomes in in-vivo experiments. The absence of complement activation by Pad-PC-Pad liposomes may indicate its use in humans.

Single-port live donor nephrectomy using a novel Curved Radius r2 Surgical System in an in vivo model.

OBJECTIVE: Single-port laparoscopic donor nephrectomy provides low morbidity and satisfactory cosmetic results for patients. The aim of this animal study was to establish a surgical technique of single-site (LESS) living donor nephrectomy using novel curved r2 CURVE manipulators specially designed for single-port access. MATERIAL AND METHODS: A total of six LESS nephrectomies were performed in three female pigs. r2 CURVE-instruments (Tuebingen Scientific Medical GmbH) were used providing a curved rotatable shaft, endless tip rotation, as well as 90° tip deflection. A 10 mm 30° extra long laparoscope, r2-curved Grasper, Maryland dissector and bipolar scissors were used for mobilization and dissection. RESULTS: All LESS nephrectomies were performed successfully. Average operative time was 80 min (range, 42-149 min). No technical problems were observed. Insertion and extraction of the instruments through the single-port were easy to conduct. The diameter of the used single-port was sufficient for safe manual organ harvesting. Potential conflict between the laparoscope and the instrument handles was avoided by using an extra long laparoscope. CONCLUSIONS: The new curved and deflectable instruments showed that single-port nephrectomy using the R2 manipulators is feasible. Single-port laparoscopic nephrectomy might be more patient-friendly and improve the willingness of potential donors to donate live organs.