3.3. Stability Comparison of DOX-Loaded Liposomes with and without α1(IV)1263–1277PA To determine the effect that the α1(IV)1263–1277PA has on liposomal stability, DOX-loaded liposomes were prepared with and without 10%α1(IV)1263–1277PA. The DOX:phospholipid ratios were 1.65:1 (1300μg DOX:μmol

phospholipid) and 1.93:1 (1520μg DOX:μmol phospholipid) for targeted [+10%α1(IV)1263–1277PA] and nontargeted [no α1(IV)1263–1277PA] liposomes, respectively. Fluorescence intensity measurements for each vesicle sample at 4, 25, or 37°C were taken at selected time points over a 30 d period. The targeted and nontargeted liposomes Inhibitors,research,lifescience,medical exhibited similar stability profiles over 918h (38d), with approximately 30–35% DOX Inhibitors,research,lifescience,medical release at 4°C (Figure 2) and 40–49% DOX release at 25 and 37°C (Figures ​(selleck compound Figures33 and ​and4).4). Within the first 6h following preparation, the liposomes again demonstrated similar and minimal DOX release. Only ≤15% release was observed for both targeted and nontargeted liposomes when incubated at 4 or 25°C (Figures ​(Figures22–3), and targeted liposomes were more stable than nontargeted liposomes after 6h at 37°C (Figure 4). Data presented here are for the targeted liposomes possessing 10% PA, but similar results were observed for liposomes incorporating 5% PA (data not shown). Thus, the presence of the α1(IV)1263–1277PA

did not serve to destabilize the liposomes used in Inhibitors,research,lifescience,medical this study. Figure 2 Temperature dependent stability comparisons between targeted [10%α1(IV)1263–1277PA] and nontargeted DSPG-DSPC liposomes loaded with DOX and stored at 4°C for 30d. DOX release was determined as … Figure 3 Temperature dependent stability comparisons between targeted [10%α1(IV)1263–1277PA] Inhibitors,research,lifescience,medical and nontargeted DSPG-DSPC liposomes loaded with DOX and stored at 25°C for 30d. DOX release was determined … Figure 4 Temperature dependent stability comparisons

between targeted [10%α1(IV)1263–1277PA] and nontargeted DSPG-DSPC liposomes loaded with DOX and stored at 37°C for 30d. DOX release was determined … 3.4. Cytotoxicity Inhibitors,research,lifescience,medical of DOX-Loaded Liposomes for Cells Varying in CD44/CSPG Content Cytotoxicity experiments were performed on metastatic melanoma M14#5 and M14#11 and fibroblast BJ cell lines. BJ fibroblasts have ~60% of the CD44 content of M14#5 melanoma cells, while M14#11 melanoma cells have ~75% of the CD44 content [23]. The variation GSK-3 in CD44/CSPG content allowed for the examination of selectivity of liposome table 5 encapsulated DOX, free DOX, and empty liposomes (Scheme 1). Empty liposomes were included due to possible unpredictable cellular responses to specific lipids within a liposome [72]. Cytotoxicity results for targeted liposomes containing 5% PA were found to be inconsistent (data not shown), so only results with 10% PA are described below. A dose-dependent response was observed for M14#5 cytotoxicity by DOX encapsulated targeted liposomes (Figure 5), with an IC50 value of 9.8μM.