Preparation of DPPC liposomes using probe-tip sonication: investigating intrinsic factors affecting temperature phase transitions

Abstract

<jats:p>Liposomes are an important tool and have gained much attention for their promise as an effective means of delivering small therapeutic compounds to targeted sites. In an effort to establish an effective method to produce liposomes from the lipid, dipalmitoyl-phosphatidylcholine or DPPC, we have found important aspects that must be taken into consideration. Here, we used probe-tip sonication to prepare liposomes on a batch scale. During this process we uncovered interesting steps in their preparation that altered the thermodynamic properties and phase transitions of the resulting liposome mixtures. Using differential scanning calorimetry to assess this we found that increasing the sonication time had the most dramatic effect on our sample, producing almost an entirely separate phase transition relative to the main phase transition. This result is consistent with reports from the current literature. We also highlight a smaller transition, which we attribute to traces of unincorporated lipid that seems to gradually disappear as the total lipid concentration decreases. Overall, sonication is an effective means of producing liposomes, but we cannot assert this method is optimal in producing them with precise physical properties. Here we highlight the physical effects at play during this process.</jats:p>

Benzoate Group Attachment to Tempo Provides Enhanced Discrimination of Liposomes Fabricated Using Human Lung Normal and Carcinoma Cells

“…Total lipid extraction was performed using a widely accepted three-component system (water, chloroform and methanol) [23]. The liposomes from the lipids extracted from healthy and cancer cell suspensions were produced using the probetip sonication method [24].…”