Cinnamic acid and its methoxy derivative-conjugated lysophosphatidylcholines-loaded solid lipid nanoparticles (LPC-SLN): In silico pharmacokinetics, design of experiments and in vitro proof of concept of anticancer activity.

Cinnamic acid derivatives are bioactive compounds with anticancer properties, including antiproliferative and pro-apoptotic effects. Their phenylpropanoid core enables cytotoxic ligand design. Despite confirmed activity of hybrids, esters, and amides, selective delivery to cancer cells remains challenging. In this work, we present the results of the in silico studies obtained for two new phospholipid conjugates of cinnamic acid: 1-cinnamoyl-2-hydroxy-sn-glycero-3-phosphocholine (CA-LPC) and 1-(3-methoxycinnamoyl)-2-hydroxy-sn-glycero-3-phosphocholine (3MCA-LPC), and their first time loading into solid lipid nanoparticles (SLN) to assess the anticancer properties in an in vitro model. Blank SLN prepared by a water-in-oil-in-water emulsion method were firstly optimized using a 2 full factorial design, by setting the concentration of surfactant, volume of external aqueous phase, and homogenization time as the independent variables, and the mean particle size (Z-Ave), polydispersity index (PI) and zeta potential (ZP) as the dependent variables. The resulting CA-LPC-loaded SLN and 3MCA-LPC-loaded SLN showed high encapsulation efficiency (88 % for CA-LPC and 85 % for 3MCA-LPC) and high loading capacity (27-28 %). The particles showed nanoscale size (162-172 nm), low polydispersity (PI < 0.2), negative ZP (-11 to -13 mV), spherical morphology, and shelf-life stability over 30 days of storage at room temperature. In vitro release studies revealed modified release profiles, indicating enhanced drug availability compared to free conjugates. In vitro assays against MV4-11 leukemia cells revealed that the encapsulation of CA-LPC and 3MCA-LPC in SLN doubled the antiproliferative activity of the conjugates compared to their free forms, while remaining less toxic to MCF-10A normal cells. These findings highlight the potential of SLN to enhance the therapeutic efficacy of cinnamic acids-phospholipid conjugates and support their further development as antileukemic drug candidates.