Centella asiatica Extract Potentiates Anticancer Activity in an Improved 3-D PHBV-Composite-CMC A549 Lung Cancer Microenvironment Scaffold

Abstract

Traditional cell culture makes use of two-dimensional (2-D) surfaces for unnatural characteristics in vitro cell response and growth. To overcome the limitation, 3-D culture models mimicking the cancer microenvironment in vivo are gaining attention. Herein, we investigated an improved composite 3-D biomimetic structure comprising poly(hydroxybutyrate-co-hydroxyvalerate) and carboxymethylcellulose (CMC) (PHBV-co-CMC) for determining the potentiation effects of Centella asiatica extract on lung cancer cells (A549). To improve its biological acceptance characteristics, the 3-D scaffold was infused with low viscosity CMC gel (0.009 ± 0.0004 Pa s) under vacuum pressure. The composite material was left immersed in complete growth media with the presence of cells to determine its optimum day of degradation prior to anti-proliferative (IC50) analysis through 2-D and 3-D cell culture. All scaffolds were found to be sustained for up to 7 days of incubation with breakages ranging from 10 to 70% (w/w). The A549 cell mortality treated with the extract (IC50 5.75 ± 1.0 µg/ml) on both porous 3-D PHBV and composite-CMC scaffolds were 70% higher than the 2-D model (30%) (p < 0.05). Visual assessment on the inner structure of the 3-D scaffold using fluorescent microscopy and scanning electron microscopy showed a scattering number of living cells on the scaffold pores wall and on the CMC gel with a glowing blue color indicating the presence of a livable cells post DAPI dye staining. Therefore, the structure of composite 3-D PHBV scaffold co-CMC produced a potential alternative method of a 3-D cell culture model to study the effectiveness of medicinal plant extracts (e.g. anticancer properties) in which might potentially mimic specific cancerous tissue ex vivo.