Investigation into the morphology and aqueous stability of electrospun PNIPAm nanofibrous scaffold cross-linked with OPEPOSS

• Main Authors: Yong, Ernest Hsin Nam, Tshai, Kim Yeow, Lim, Siew Shee
• Format: Conference Proceeding
• Language: English
• Subjects: Cell culture; Cell membranes; Crosslinking; Curing; Electrospinning; Flasks; Morphology; Nanofibers; Polyhedral oligomeric silsesquioxane; Polyisopropyl acrylamide; Pore size; Porosity; Scaffolds; Stability; Surface area; Temperature control
• ISSN: 0094-243X; 1551-7616
• DOI: 10.1063/5.0183682

Conventional cell culture on 2D surfaces such as culture flasks and tissue culture dishes have limited surface area for cell growth. Additionally, as cells reach confluence, standard cell harvesting techniques utilizing enzyme or mechanical scraping could cleave proteins on cell membranes resulting in reduced cell yield. This work presents the fabrication of a thermally responsive poly(N-isopropylacrylamide) (PNIPAm) nanofibrous scaffold by electrospinning. Electrospun nanofibrous scaffold presents a 3D microenvironment with high surface area for cell attachment, and PNIPAm based scaffolds offer the potential for a non-invasive cell harvesting mechanism by temperature control. PNIPAm was synthesized via radical polymerization yielding polymer with an average molecular weight of 381,000 g/mol and electrospun into randomly aligned nanofibers. Since linear uncross-linked PNIPAm exhibit poor aqueous stability, the electrospun nanofibrous scaffold was cross-linked with octaglycidyl polyhedral oligomeric silsesquioxane (OPEPOSS) to mitigate the instant aqueous dissolution of PNIPAm during cell culture. The OPEPOSS cross-linked PNIPAm nanofibrous scaffold was cured for 4 h at 120 °C under atmospheric pressure and its resulting difference in nanofibrous morphology is highlighted in this work. Prior to curing, PNIPAm nanofibrous scaffold exhibit fiber diameter of 369.24 ± 154.38 nm, pore size of 2.63 ± 2.98 µm and porosity of 74.4 %. After curing, its fiber diameter increased to 436.35 ± 187.04 nm while pore size and porosity decreased to 1.24 ± 1.27 µm and 63.6 %, respectively. Additionally, cross-linking with OPEPOSS showed significant improvement in the aqueous stability of electrospun PNIPAm nanofibers as compared to electrospun neat PNIPAm.