Assessment of Intracellular Delivery Potential of Novel Sustainable Poly(δ-decalactone)-Based Micelles.

Biodegradable polymers from renewable resources have attracted much attention in recent years within the biomedical field. Lately, poly(delta-decalactone) based copolymer micelles have emerged as a potential drug delivery carrier material as a sustainable alternative to fossil-based polymers. However, their intracellular drug delivery potential is not yet investigated and therefore, in this work, we report on the synthesis and cellular uptake efficiency of poly(delta-decalactone) based micelles with or without a targeting ligand. Folic acid was chosen as a model targeting ligand and Rhodamine B as a fluorescent tracer to demonstrate the straightforward functionalisation aspect of copolymers. The synthesis of block copolymers was accomplished by a combination of facile ring-opening polymerisation and click chemistry to retain the structure uniformity. The presence of folic acid on the surface of micelles with diameter similar to 150 nm upsurge the uptake efficiency by 1.6 fold on folate receptor overexpressing MDA-MB-231 cells indicating the attainment of targeting using ligand functionality. The drug delivery capability of these carriers was ascertained by using docetaxel as a model drug, whereby the in vitro cytotoxicity of the drug was significantly increased after incorporation in micelles 48 h post incubation. We have also investigated the possible endocytosis route of non-targeted micelles and found that caveolae-mediated endocytosis was the preferred route of uptake. This work strengthens the prospect of using novel bio-based poly(delta-decalactone) micelles as efficient multifunctional drug delivery nanocarriers towards medical applications.