An in vitro three-dimensional model of tumor tissue, or “cylindroid,” invented by Neil Forbes of the Chemical Engineering Department, was the vehicle used for research in an article published in Nature Nanotechnolgy. The journal is part of the prestigious Nature Publishing Group, a spinoff of Nature, the leading international scientific journal, founded in 1869. The paper is entitled “Tuning payload delivery in tumour cylindroids using gold nanoparticles” and appeared on Nature Nanotechnology's website April 11.
The authors are Byoungjin Kim, Bhushan J. Toley, and Forbes of the Chemical Engineering Department, and Gang Han, Chae-kyu Kim, and Vincent M. Rotello of the Chemistry Department.
A cylindroid is a sort of cylindrical “rollup” sandwich, about 800 microns or one millimeter in diameter, made from alternating layers of plastic dividers and human cancer cells. The cylindroid allows researchers in the laboratory to use a microscope and actually view the various micro-environments within, as if they could magically peer inside the body at a real human tumor.
As the article’s abstract explains, “Nanoparticles have great potential as controllable drug delivery vehicles because of their size and modular functionality. Timing and location are important parameters when optimizing nanoparticles for delivery of chemotherapeutics. Here, we show that gold nanoparticles carrying either fluorescein or doxorubicin molecules move and localize differently in an in vitro three-dimensional model of tumour tissue, depending on whether the nanoparticles are positively or negatively charged. Fluorescence microscopy and mathematical modelling show that uptake, not diffusion, is the dominant mechanism in particle delivery. Our results indicate that positive particles may be more effective for drug delivery because they are taken up to a greater extent by proliferating cells. Negative particles, which diffuse more quickly, may perform better when delivering drugs deep into tissues. An understanding of how surface charge can control tissue penetration and drug release may overcome some of the current limitations in drug delivery.”
Nature Nanotechnology is a multidisciplinary journal that publishes papers of the highest quality and significance in all areas of nanoscience and nanotechnology. The journal covers research into the design, characterization, and production of structures, devices, and systems that involve the manipulation and control of materials and phenomena at atomic, molecular, and macromolecular scales.