الفهرس 
صفحة العنوانOnly 14 pages are availabe for public view
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Abstract
Three-dimensional (3D) tissue culture has attracted great attention as a result of increasing demand to replace the conventional two-dimensional (2D) cell culture with more reliable methods, especially for understanding the sophisticated nature of the native tumor microenvironment. Therefore, numerous studies on developing techniques for 3D tissue culture have been conducted. However, most of them are laborious, expensive and limited to spheroids formation. In this study, low cost and highly effective chitosan/polyethylene oxide (CS/PEO) nanofibers scaffolds were developed as an artificial environment in which biological cells are permitted to grow and interact with their surroundings in all three dimensions forming the spontaneously 3D breast cancer microtissue and 3D lung cancer spheroids.
Experimentally, random, and aligned CS/PEO nanofibrous scaffolds were prepared with different chitosan concentration (2wt% and 4wt%) blended with PEO at dry ratio 2:1 (C2P1) and 4:1 (C4P1), respectively to be electrospun at different electrospinning processing parameters producing scaffolds with different surface topography. The relation between surface topography and electrospinning processing parameters were studied as pump flow rate which ranged from 0.006 to 0.024 ml/min. The CS/PEO scaffolds were structurally and morphologically characterized using different techniques as scanning electron microscope, atomic force microscope, contact angle, porometer, and in silico analysed into the bargain. The obtained data showed average fibers diameter for both random and aligned were in the range of 83 to 137 nm for the C2P1 scaffolds and from 134 to 199 nm for the C4P1 scaffolds. The results indicate that as polymer concentration and pump flow rates increase the fibers diameter, surface roughness, pore size, and wettability increase.
To test the applicability of the fabricated scaffolds, different cancer cell lines (Colo320, HepG2, A549, and MCF-7) were cultured on their surfaces. The grown cells were morphologically and biochemically evaluated. The results also showed a high proliferation rate for the grown cells on scaffolds compared to cells grown on 2D adherent plates (TCP). Moreover, the cells appeared highly compacted and connected with gap-tight junctions. Different cell morphology and behaviour have been recorded according to type of cell lines, which makes our scaffolds act as a 3D platform for specific cell lines (MCF-7, A549) and 2D platforms for other cell lines (Colo320, HepG2). Moreover, novel 3D breast cancer tissues were spontaneously formed within 10 days of culture on the C2P1 nanofibrous scaffolds with random and aligned surface topography that imitates the microenvironment of the in vivo tumor.
Our platform has many advantages as the fabricated scaffolds are cheap and produced by solution electrospinning which is an economic method. This novel platform will be useful in the evaluation of therapeutic strategy and point-of-care platform to a patient’s specific cancer cell biopsy with different chemotherapy and tailor personalized medicine. The spontaneously formed 3D cancer tissue is an essential step in drug development and screening.
Keywords:
Nanofibers, Electrospinning, Surface topography, Cancer cell lines, Two- dimensional, Three - dimensional, Spheroids, 3D breast cancer microtissue.