Biodegradable concanavalin A functionalized polycaprolactone nanoparticle: A promising avenue for cancer therapy

Receptor-based tumor-selective delivery of therapeutic efficacy and therapeutic index of cytotoxic drugs that exhibit dose-limiting toxicity is observed. Concanavalin A (Con A) was selected as the ligand for the proposed system, which was appended to the polycaprolactone nanoparticles (NPs) carrying the drug to be a very efficient approach for the treatment of cancer.

Preparation of plain polycaprolactone nanoparticles was carried out employing the emulsion diffusion evaporation technique. Con A was conjugated using carbodiimide chemistry by coupling -COOH group on the surface of nanoparticles. The paclitaxel-loaded Con A-conjugated nanoparticles were further subjected to the characterization of various parameters, that is, surface morphology, particle size, and polydispersity index. In vitro drug release study of both the formulations (plain & conjugated) was done using a dialysis tube up to 48 h in phosphate buffer (pH 7.4).

Studies done in xenograft models evidently propose a dose-dependent cytotoxicity response, that is, shrink in % cell growth with increase in the concentration of the drug. The fluorescence photomicrograph clearly revealed the access of the Con A-conjugated nanoparticles to the tumor. A noteworthy biodistribution difference of the paclitaxel from prepared systems was observed. At the same time, Con A-coupled nanoparticles increased the accumulation of paclitaxel in the tumor cells.

Hence, the Con A-conjugated nanoparticles formulation as compared to uncoupled solid lipid nanoparticles formulation and free drug solution showed nearly two times higher uptake because of the lectin receptors on the surface of tumors. Hence, it was envisaged to design polymeric nanoparticles which would be administered intravenously for better therapeutic efficacy.