Development of oxaliplatin encapsulated in magnetic nanocarriers of pectin as a potential targeted drug delivery for cancer therapy

Superparamagnetic iron oxide nanoparticles (SPIONs) and oxaliplatin (OHP) were in-situ encapsulated in pectin cross-linked with Ca²⁺ forming 100–200 nm sized magnetically functionalized pectin nanocarriers, referred here as MP-OHP nanocarriers. The scanning electron microscopy (SEM) and transmission electron microscopy (TEM) studies revealed formation of spherical nanostructures. The magnetic measurements by vibration sample magnetometer (VSM) revealed high saturation magnetization (M_s=45.65 emu/g). The superparamagnetic property of MP-OHP was confirmed from the blocking temperature (T_B) determined from field cooled and zero field cooled magnetization, measured by superconducting quantum unit interference device (SQUID) magnetometry. The stability of the aqueous dispersion of MP-OHP nanocarriers was confirmed from its high zeta potential (−30.5 mV). The drug encapsulation efficiency (55.2±4.8% w/w) and the drug loading content (0.10±0.04 wt%) in MP-OHP nanocarriers were determined from corresponding platinum contents in OHP and MP-OHP batches measured by inductively coupled plasma mass spectrometry (ICPMS). These nanocarriers exhibited a sustained release of OHP in phosphate buffer solution maintained at pH 5.5 and 7.4, where the drug release profile satisfied a combination of diffusion and swelling controlled mechanism. The cytotoxicity effect of MP-OHP nanocarriers was studied on MIA-PaCa-2 (pancreas) cancer cell line, where the GI₅₀ values were more than 5 mg/mL and it exhibited 10 folds higher cytoxicity than the equivalent concentration of free drug.