Tiny Fibres, Big Impact: 3D Scaffolds from Nanofibres of Electrospun Smart Polymer, PNIPAm

What is it about?

Cell culture is an indispensable tool with applications in vaccine production, stem cell research, drug development, biomedical research, environmental toxicology studies, cancer research, and so on. Its importance lies in its ability to cultivate and maintain cells outside their natural environment in a controlled and reproducible laboratory setting. However, in conventional cell culture systems, 2D surfaces such as culture flasks and tissue culture dishes exhibit limited surface area for cell growth, requiring a lot of space with very limited cell yield. A 3D microenvironment composed of nano-sized fibers (nanofibers) can be developed to not only increase the surface area within a smaller space but also to mimic the structure of the native environment where cells grow (i.e., in the body). This work dives into the development of a 3D cell culture platform made of fibers more than a hundred times thinner than human hair, produced by the state-of-the-art electrospinning technique. A biocompatible smart polymer, poly(N-isopropylacrylamide) (PNIPAm), capable of reversible transition between hydrophilic and hydrophobic states across ~32 °C (close to human physiological temperatures), was used as the base material for these fibers. This gives rise to a culture platform that could spontaneously release of cells during harvest simply by cooling to temperature well below 32 °C instead of the conventional practice by mechanical scraping or using the enzyme, trypsin.

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Why is it important?

PNIPAm is a valuable biopolymer known to be non-toxic to cells. By careful temperature control, its responsiveness to heat allows it to be used as a switchable platform to have a different degree of interaction with anchorage-dependent cells (all cells except those that circulate in the blood). This work explores the development of a PNIPAm-based scaffold from its synthesis to processing into nanofibers. More importantly, it provides insight into addressing one of its biggest drawbacks that limits its use: its stability in water-based mediums. This serves as part of the foundational work for an alternative cell culture system with the objective of increasing cell culture yields, furnished with a non-invasive, temperature-controlled cell release mechanism.

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