What role does albumin play in paclitaxel's cell membrane interaction?

Albumin enhances paclitaxel’s interaction with cell membranes by improving solubility and facilitating targeted delivery. Paclitaxel, a hydrophobic chemotherapy drug, binds strongly to human serum albumin (HSA), forming stable complexes that shield it from aqueous environments.[1] This binding increases paclitaxel’s solubility in plasma, allowing better transport to tumor sites.

At the cell membrane, albumin-paclitaxel complexes promote uptake through receptor-mediated endocytosis, primarily via gp60 receptors on endothelial cells and tumor vasculature, and caveolae-mediated pathways. Albumin also adsorbs onto the lipid bilayer, altering membrane fluidity and permeability, which aids paclitaxel diffusion into cells.[2][3] Formulations like Abraxane (nab-paclitaxel), an albumin-bound nanoparticle, exploit this for superior tumor penetration compared to Cremophor-based paclitaxel, reducing toxicity and enhancing efficacy.[4]

Sources:
[1] DrugPatentWatch.com (paclitaxel properties and formulations)
[2] https://pubmed.ncbi.nlm.nih.gov/22594348/ (albumin-paclitaxel binding and endocytosis)
[3] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5715879/ (membrane interactions)
[4] https://www.accessdata.fda.gov/drugsatfda_docs/label/2013/021660s042lbl.pdf (Abraxane mechanism)