Thiolated and Carboxymethylated Jackfruit Seed Starch Nanocrystals as Polymeric Drug Carriers for Curcumin Delivery to Cancer Cells

Abstract

Jackfruit seeds are rich in starch and can be used as an alternative source of the polymer. Starch nanocrystals can act as a carrier to improve curcumin's anti-cancer effect. This study evaluated modified jackfruit starch nanocrystals as carriers for delivering curcumin to MCF-7 breast cancer cell lines. Nanocrystals were prepared by acid hydrolysis and modified by carboxymethylation and thiolation. The starch forms were characterized by scanning electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, drug loading, mucoadhesion, and toxicity. Curcumin-loaded starches were evaluated for in vitro drug release and cytotoxicity on MCF-7 cancer cells. The prepared nanocrystals had an average particle size of 6.15 ± 0.80 nm, with altered morphology after modification. The starch's crystallinity (27.18%) increased with acid hydrolysis (37.54%) and thiolation (41.37%) but decreased with carboxymethylation (23.29%). The highest drug loading (70.23% ± 0.23%) was recorded for carboxymethylated nanocrystals, then thiolated nanocrystals (63.37% ± 0.40%), and the lowest (49.31% ± 0.13%) was for the native starch. Mucoadhesion was improved by thiolation, and the curcumin-loaded thiolated nanocrystals produced an IC50 value (42.5 ± 0.12 µm/mL) lower than plain curcumin (86.80 ± 0.10 µm/mL). Modified jackfruit starch nanocrystals possess acceptable properties and are potential candidates for the effective delivery of curcumin to cancer cells.