Preparation of a liposomal delivery system and its in vitro release of rapamycin.

The aim of this study was to prepare a liposomal delivery system for rapamycin and study its in vitro release characteristics. The results may provide a foundation for the further development of a liposomal delivery system for rapamycin and the establishment of a new active treatment method targeted towards the cellular components of atherosclerotic plaques. The ethanol injection method was used to prepare rapamycin-containing liposomes. The formulation was optimized by orthogonal design, and the degree of rapamycin release by the liposomes was measured by the reverse dialysis method. Orthogonal testing showed that the optimum formulation had a phospholipid concentration of 4%, a phospholipid-cholesterol mass ratio of 8:1, a drug-lipid mass ratio of 1:20 and an aqueous phase pH of 7.4. Rapamycin-containing liposomes with an encapsulation efficiency of 82.11±2.13% were prepared, and the in vitro release of rapamycin from the liposomes complied with a first-order kinetic equation. In conclusion, the formulation was optimized, the prepared liposomes had a high rapamycin encapsulation rate and good reproducibility, and their in vitro release had a certain delayed-release effect.

The clinical study of autologous peripheral blood stem cell transplantation by intracoronary infusion in patients with acute myocardial infarction (AMI).

PURPOSE: To investigate the effects and safety of autologous peripheral blood stem cell (PBSCs) transplantation by intracoronary infusion in patients with acute myocardial infarction (AMI). METHODS: 70 patients with AMI were allocated to two groups, one was PBSCs transplantation group (n=35) that received optimal post-infarction medical treatment (standard drug and coronary artery intervention therapy) and intracoronary transplantation of PBSCs; the other was control group (n=35) that received optimum post-infarction medical treatment (standard drug and coronary artery intervention therapy). The PBSCs transplantation group received granulocyte colony-stimulating factor (G-CSF: Filgrastim, 300 microg) with the dose of 300-600 microg/day to mobilize the stem cell, and the duration of administration G-CSF was 5 days. On the sixth day, PBSCs were separated by Baxter CS 3000 blood cell separator into suspend liquid 57 ml. Then, the suspend liquid was transferred into the infarct-related artery (IRA) by occluding the over-the-wire balloon and infusing artery through balloon center lumen. In the process of the mobilization, separation and intracoronary infusion of PBSCs, the complications have been investigated. Changes in left ventricular function were assessed at 6-month follow-up. RESULTS: 35 cases had finished follow-up in the treated group, while 23 cases in control group. After 6 months, within the treated group, there was a significant improvement in global left ventricular function ejection fraction (EF) from a baseline of 50.0+/-8.2% to 57.1+/-7.8% (P<0.0001), wall motion score index (WMSI) from 1.219+/-0.190 to 1.101+/-0.118 (P<0.0001), left end-systolic volume (ESV) from 63.8+/-23.9 ml to 52.6+/-20.3 ml (P=0.01) and left end-diastolic volume (EDV) from 134.2+/-36.7 ml to 119.2+/-30.3 ml (P=0.07); in the control group, there was no significant improvement in EF, WISM, EDV and ESV (P=0.490, 0.259, 0.117, 0.395). After 6-month follow-up, according to treatment group vs. control group, there was a significant improvement in EF from 57.1+/-7.8 to 52.6+/-5.7 (P=0.041) and WISM from 1.101+/-0.118 to 1.184+/-0.138 (P=0.034). There were a total of 25 cases with complications during the mobilization, separating and infusion of PBSC. The incidence of complications relating to mobilization was 37.1% (13/35), relating to separating was 14.3% (5/35) and relating to intracoronary infusion was 20.0% (7/35). No death was observed. CONCLUSION: Autologous PBSCs transplantation by intracoronary infusion is feasible and safe, and it can improve left ventricular function in the 6-month follow-up.

[Safety and efficacy of intracoronary transplantation of G-CSF mobilized autologous peripheral blood stem cells in patients with acute myocardial infarction].

OBJECTIVE: To investigate the safety and efficacy of intracoronary transplantation of G-CSF mobilized autologous peripheral blood stem cells in patients with acute myocardial infarction (AMI). METHODS: Patients with AMI were randomly assigned to receive intracoronary PBSCs transplantation following bone marrow cells mobilization by granulocyte colony-stimulating factor (300-600 microg/day subcutaneously for 5 days) in addition to standard therapy (standard drug therapy and PCI, PBSCs transplantation group, n = 35) or standard therapy (standard drug therapy and PCI, n = 35). One day after G-CSF treatment was finished the patient's mononuclear cells were harvested by Baxter CS 3000 blood cell separator in a volume of 57 ml and then transferred into the infarct related artery by occluding the over the wire balloon and infusing artery through balloon center lumen. Complications during intervention and left ventricular function at baseline and 6 months thereafter were monitored. RESULTS: No severe side effects of G-CSF treatment could be observed. Malignant arrhythmias were not observed either. Left ventricular function was significantly improved 6 months after G-CSF mobilized autologous peripheral blood stem cell transplantation compared to baseline (global left ventricular function ejection fraction: 57.1 +/- 7.8 vs. 50.0 +/- 8.2%, P < 0.0001; WMSI: 1.101 +/- 0.118 vs. 1.219 +/- 0.190, P < 0.0001; left end-systolic volume: 52.6 +/- 20.3 vs. 63.8 +/- 23.9 ml, P = 0.01 and left end-diastolic volume: 119.2 +/- 30.3 vs. 134.2 +/- 36.7 ml, P = 0.07) while these parameters remained unchanged in the control group. CONCLUSION: The present study demonstrates that G-CSF mobilized autologous intracoronary PBSCs transplantation is a safe and feasible treatment for patients with AMI and global left ventricular function is improved and left ventricular remodeling attenuated at six-month follow-up.