| The skin flap is the most commonly used means for wound repair in plastic surgery. For the prevention of flap necrosis and ensuring flap survival rate, advance delay of the flap is still recognized as the most effective way in raising the survival rate. Surgical delay can get a high survival rate, but need for secondary surgery, much more long hospital stay, the patients'burden is increased.At present, some progress has made in drug flap delay, Karacaoglu et al have shown that local injection of adrenaline microspheres can make the role of delayed in flap. In this study, we use simple injection of epinephrine drugs, and make sure a good delayed effect of the flap. We prepare the adrenaline flexible nano-liposome according to the flexible nano-liposomes could serve as a transdermal drug delivery carrier and it's slow controlled release characteristics. A series test show that adrenaline flexible nano-liposome could be slow-release in transdermal drug delivery, and the preparation technology is feasible, and the quality control method is simple and reliable.In this study, ultra-long cross-regional flap was designed in the back of the rats, comparing survival rate of adrenaline flexible nano-liposome transdermal delivery groups, other forms of epinephrine treatment group, surgery group and control group, the results showed that:delay effect can be greatly improved by adrenaline flexible nano-liposome transdermal delivery.At the same time, we can avoid the painful delay surgery in patients, cut medical costs and get a broad clinical application. Adrenaline flexible nano-liposome transdermal delivery can replace the traditional surgical method as a novel idea of non-invasive drug delivery way.Objective:The purpose of the present study was to prepare epinephrine nano-flexible liposomes and to exosyndrome it.Method:Epinephrine nano-Flexible liposomes were prepared by reverse evaporation method, it's encapsulation efficiency and liquidity were observed. Flexible liposome size was measured under the conditions of different ultrasonic to determine the best experimental values of ultrasonic power and time. The morphous of Flexible nano-liposome particle was precisely measured under the transmission electron microscope under the standard experiments state.Results:The encapsulation efficiency of water-soluble hydrochloride Epinephrine flexible liposomes was 61.83%, the relative permeation rate of flexible liposome colloidal solution was 70.49%. Observed by the transmission electron microscope, epinephrine flexible nano-liposomes can get a stable nano-particle size of about 80nm under the ultrasonic conditions of 50% power and 14 minutes.Conclusion:The preparation technology of adrenaline flexible liposomes is feasible, the quality control method is simple and reliable. The adrenaline flexible liposomes'encapsulation efficiency and particle size are in line with general requirements of the pharmacopoeia.Objective:The purpose of the present study was to research the feasibility of adrenaline flexible nano-liposome transdermal delivery.Methods:The methods of analysis adrenaline by high performance liquid chromatography was established and using amended Franz diffusion cells to transdermal delivery of adrenaline flexible nano-liposome across rat skin in vitro. The cumulative transdermal absorption percentages were observed after 24h.Results:Chromatographic conditions were mobile phase:methanol: 0.02mol/L potassium dihydrogen phosphate solution (V/V)=25:75, flow rate:1.0 mL·min-1, detection wavelength:280nm, the cumulative transdermal absorption percentage in 24h was 47.6%. Conclusion:adrenaline flexible nano-liposome penetration rate and absorption rate are in line with general requirements of the pharmacopoeia.Objective:The purpose of the present study was to explore new ways in flap delay, enhance the efficiency of flap delay, reduce surgical trauma and the suffering of patients, explore the feasibility of non-invasive transdermal method.Method:252 healthy male Wister rats were taken back-flap about 5 cm×1 cm, across the midline area 2.5 cm, bilateral main vessel in the middle zone had a constant anastomosis. The 252 rats were randomly divided into 6 groups:surgical delay group (A), epinephrine injection delayed group (B), normal saline control group (C), epinephrine injection liposome delayed group (D group), epinephrine liposome transdermal delivery delay group (E group),epinephrine liposome transdermal and injected delayed group (F group), each flap were then divided into groups, without delay (A1, B1, C1, D1, E1, F1), delayed three days (A2, B2, C2, D2, E2, F2), delayed 7 days (A3, B3, C3, D3, E3, F3), delayed 14 days (A4, B4, C4, D4, E4, F4). Capillary density, lactic acid content, VEGF expression and oxide gelatin infusion in general samples were observed, comparing flap survival rate of each group.Results:Since delayed three days, A group flaps'blood vessel density were increased in the midline area, lactic acid concentration were descending with the extended delay time, following by increased flap survival rate. In B and D group delay 7 days and 14 days after the injection,lactic acid in a relatively stable value, but F and E group had sustained rise. The survival rate of A group, B group, D group, E group and F group were increasing according to the observation time. A group, B group and D group had no significant statistically difference between groups (p>0.01); capillary density, lactic acid content of the three groups had no significant statistically difference (p> 0.01). E group and the F group are better than ABD groups in all indicators, there was a significant statistical difference (p<0.01). Group F was better than E group, there was a significant statistical difference (p<0.01). Compared A, B, D, E, and F group with C group, there was a significant statistical difference (p <0.01).Conclusion:We made use of the slow-release effect of liposomes, and prepared nano-flexible liposomes epinephrine, through the transdermal delivery, improved skin flap survival rate, created a new type of non-invasive method of delays with a high clinical value.
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