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We present a high-performance liquid chromatography (HPLC) method suitable for the analysis of epirubicin and its metabolite epirubicinol in saliva and plasma. Preparation of saliva and plasma samples was performed by extraction of analytes with a chloroform:2-propanol mixture (6:1, vol/vol) and evaporation of the organic phase to dryness under vacuum at a temperature of approximately 45 degrees C. The chromatographic analysis was carried out by reversed-phase isocratic elution of the anthracyclines with a Chromsep stainless steel HPLC column (150 x 4.6 mm I.D.) filled with Nucleosil 100 S C(18) material, particle size 5 micro m. The detection was accomplished by spectrofluorimetry at excitation and emission wavelengths of 474 and 551 nm, respectively. The anthracyclines eluted within 10 min of injection, and the method appeared to be specific. The method is linear over a concentration range of 5 to 1000 micro g/L for epirubicin and 2 to 400 micro g/L for epirubicinol (r > 0.99) in both saliva and plasma. The recoveries from saliva and plasma of epirubicin, epirubicinol, and the internal standard doxorubicin were 88.9 and 69.0%, 87.6 and 77.3%, and 80 and 67.9%, respectively. The lower limit of quantification was 5 micro g/L for epirubicin and 2 micro g/L for epirubicinol. The method proved to be precise and accurate, as the within-day and between-day coefficients of variation were less than 10%. Overall results indicate that our method is suitable for the bioanalysis of epirubicin and epirubicinol in saliva as well as plasma.

Vascular endothelial growth factor (VEGF) is the major regulating factor for the formation of new blood vessels, also known as angiogenesis. VEGF is often incorporated in synthetic scaffolds to promote vascularization and to enhance the survival of cells that have been seeded in these devices. Such applications require sustained local delivery of VEGF of around 4 weeks for stable blood vessel formation. Most delivery systems for VEGF only provide short-term release for a couple of days, followed by a release phase with very low VEGF release. We now have developed VEGF-loaded polymeric microspheres that provide sustained release of bioactive VEGF for 4 weeks. Blends of two swellable poly(ε-caprolactone)–poly(ethylene glycol)–poly(ε-caprolactone)- b -poly( l -lactide) ([PCL–PEG–PCL]- b -[PLLA])-based multiblock copolymers with different PEG content and PEG molecular weight were used to prepare the microspheres. Loading of the microspheres was established by a solvent evaporation-based membrane emulsification method. The resulting VEGF-loaded microspheres had average sizes of 40–50 μm and a narrow size distribution. Optimized formulations of a 50:50 blend of the two multiblock copolymers had an average VEGF loading of 0.79 ± 0.09%, representing a high average VEGF loading efficiency of 78 ± 16%. These microspheres released VEGF continuously over 4 weeks in phosphate-buffered saline pH 7.4 at 37 °C. This release profile was preserved after repeated and long-term storage at −20 °C for up to 9 months, thereby demonstrating excellent storage stability. VEGF release was governed by diffusion through the water-filled polymer matrix, depending on PEG molecular weight and PEG content of the polymers. The bioactivity of the released VEGF was retained within the experimental error in the 4-week release window, as demonstrated using a human umbilical vein endothelial cells proliferation assay. Thus, the microspheres prepared in this study are suitable for embedment in polymeric scaffolds with the aim of promoting their functional vascularization.

A sensitive and selective LC-MS/MS method has been developed and validated for the determination of free and total dopamine in human plasma. This article demonstrates how essential careful optimization of the sample preparation procedures was for developing a successful method.

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