Synthesis and characterization of nuclear nano-theranostic formulation for metastatic ovarian cancer treatment

Background and Aim: Ovarian cancer (OC) is frequently diagnosed at an advanced stage, limiting treatment options. Luteinizing hormone-releasing hormone (LHRH) receptors are overexpressed on ovarian tumour cells, enabling receptor-mediated targeting. Nano-particles (NPs) offer precise drug delivery. In nuclear medicine, theranostic NPs are promising tools for delivering both therapeutic and diagnostic agents. In our previous study, we synthesised and radiolabelled Poly-lactic-co-glycolic acid (PLGA) NPs in a single step by using an innovative microfluidic technique. This study focuses on the functionalization of PLGA NPs with LHRH for targeted ovarian cancer therapy.
Methods: PLGANPs were synthesized using a microfluidic technique, providing precise control over particle size and reproducibility. Technetium-99m (99mTc) was used to radio-label PLGA NPs. Non-radioactive formulations were synthesized under similar conditions and functionalized with LHRH. Particle size and surface charge were assessed via dynamic light scattering (DLS), and LHRH conjugation efficiency was quantified using high-performance liquid chromatography (HPLC). Cellular uptake and cytotoxicity were evaluated in LHRH receptor-positive ES-2 ovarian cancer cells.
Results: PLGA NPs synthesized at a total flow rate of 15 mL/min and a 5:1 flow rate ratio showed optimal size and radiolabelling efficiency. LHRH conjugation achieved ~70% efficiency. Zeta potential measurements confirmed successful surface modification during activation and peptide attachment. Cellular uptake and viability studies were conducted to evaluate the targeting efficiency and biocompatibility of LHRH-conjugated PLGA nanoparticles. Fluorescence intensity showed significantly higher uptake of LHRH-PLGANPs in LHRH receptor-positive ES-2 ovarian cancer cells compared to native NPs, confirming receptor-mediated internalization. In contrast, uptake in control cells remained low, indicating non-specific binding. Cell viability revealed no toxicity of PLGA NPs.
Conclusion: The microfluidic technique facilitated rapid and efficient NPs formulation, minimizing batch variability. LHRH-functionalized PLGA NPs demonstrated selective uptake in OC cells, supporting their potential as an effective targeted delivery system and future nuclear theranostic tool for OC management.