@article{petrella_levit_fesmire_tang_sano_2022, title={Polymer Nanoparticles Enhance Irreversible Electroporation In Vitro}, volume={69}, ISSN={["1558-2531"]}, DOI={10.1109/TBME.2022.3143084}, abstractNote={Expanding the volume of an irreversible electroporation treatment typically necessitates an increase in pulse voltage, number, duration, or repetition. This study investigates the addition of polyethylenimine nanoparticles (PEI-NP) to pulsed electric field treatments, determining their combined effect on ablation size and voltages. U118 cells in an in vitro 3D cell culture model were treated with one of three pulse parameters (with and without PEI-NPs) which are representative of irreversible electroporation (IRE), high frequency irreversible electroporation (H-FIRE), or nanosecond pulsed electric fields (nsPEF). The size of the ablations were compared and mapped onto an electric field model to describe the electric field required to induce cell death. Analysis was conducted to determine the role of PEI-NPs in altering media conductivity, the potential for PEI-NP degradation following pulsed electric field treatment, and PEI-NP uptake. Results show there was a statistically significant increase in ablation diameter for IRE and H-FIRE pulses with PEI-NPs. There was no increase in ablation size for nsPEF with PEI-NPs. This all occurs with no change in cell media conductivity, no observable degradation of PEI-NPs, and moderate particle uptake. These results demonstrate the synergy of a combined cationic polymer nanoparticle and pulsed electric field treatment for the ablation of cancer cells. These results set the foundation for polymer nanoparticles engineered specifically for irreversible electroporation.}, number={7}, journal={IEEE TRANSACTIONS ON BIOMEDICAL ENGINEERING}, author={Petrella, Ross A. and Levit, Shani L. and Fesmire, Christopher C. and Tang, Christina and Sano, Michael B.}, year={2022}, month={Jul}, pages={2353–2362} }
 @article{tang_saquing_morton_glatz_kelly_khan_2014, title={Cross-linked Polymer Nanofibers for Hyperthermophilic Enzyme Immobilization: Approaches to Improve Enzyme Performance}, volume={6}, ISSN={["1944-8244"]}, DOI={10.1021/am5033633}, abstractNote={We report an enzyme immobilization method effective at elevated temperatures (up to 105 °C) and sufficiently robust for hyperthermophilic enzymes. Using a model hyperthermophilic enzyme, α-galactosidase from Thermotoga maritima, immobilization within chemically cross-linked poly(vinyl alcohol) (PVA) nanofibers to provide high specific surface area is achieved by (1) electrospinning a blend of a PVA and enzyme and (2) chemically cross-linking the polymer to entrap the enzyme within a water insoluble PVA fiber. The resulting enzyme-loaded nanofibers are water-insoluble at elevated temperatures, and enzyme leaching is not observed, indicating that the cross-linking effectively immobilizes the enzyme within the fibers. Upon immobilization, the enzyme retains its hyperthermophilic nature and shows improved thermal stability indicated by a 5.5-fold increase in apparent half-life at 90 °C, but with a significant decrease in apparent activity. The loss in apparent activity is attributed to enzyme deactivation and mass transfer limitations. Improvements in the apparent activity can be achieved by incorporating a cryoprotectant during immobilization to prevent enzyme deactivation. For example, immobilization in the presence of trehalose improved the apparent activity by 10-fold. Minimizing the mat thickness to reduce interfiber diffusion was a simple and effective method to further improve the performance of the immobilized enzyme.}, number={15}, journal={ACS APPLIED MATERIALS & INTERFACES}, author={Tang, Christina and Saquing, Carl D. and Morton, Stephen W. and Glatz, Brittany N. and Kelly, Robert M. and Khan, Saad A.}, year={2014}, month={Aug}, pages={11899–11906} }
 @article{sullivan_tang_kennedy_talwar_khan_2014, title={Electrospinning and heat treatment of whey protein nanofibers}, volume={35}, ISSN={["1873-7137"]}, DOI={10.1016/j.foodhyd.2013.07.023}, abstractNote={The ability to develop nanofibers containing whey proteins presents a unique opportunity to exploit the inherent benefits of whey protein with that of the desirable attributes of nanofibers. In this study, aqueous whey protein solutions, both whey protein isolate (WPI) and one of its major components beta-lactoglobulin (BLG), are electrospun into nanofibers in conjunction with a spinnable polymer, poly(ethylene oxide) (PEO). WP:PEO solution composition as high as 3:1 and with average fiber diameters ranging from 312 to 690 nm are produced depending on polymer composition and concentration. WP/PEO solutions are also successfully electrospun at acidic pH (2 ≤ pH ≤ 3), which could improve shelf life. FTIR analysis of WP/PEO fiber mat indicates some variation in WP secondary structure with varying WPI concentration (as WPI increases, % α-helix increases and β-turn decreases) and pH (as pH decreases from neutral (7.5) to acidic (2), % β-sheet decreases and α-helix increases). XPS also confirms the presence of WP on the surface of the blend fibers, augmenting the FTIR analysis. Interestingly, WP/PEO composite nanofibers maintain its fibrous morphology at temperatures as high as 100 °C, above the 60 °C PEO melting point. In addition, the mats swell in water and retain a fibrous quality which makes them desirable for application in regenerative medicine. Finally, we incorporate a small hydrophobic molecule Rhodamine B (RhB) as a model flavonoid into WP/PEO nanofiber mats. The BLG:PEO nanofibers qualitatively exhibit improved fiber quality and RhB distribution compared to PEO nanofibers; however, no effect on the release profile is observed.}, journal={FOOD HYDROCOLLOIDS}, author={Sullivan, Stephanie T. and Tang, Christina and Kennedy, Anthony and Talwar, Sachin and Khan, Saad A.}, year={2014}, month={Mar}, pages={36–50} }
 @article{tang_saquing_sarin_kelly_khan_2014, title={Nanofibrous membranes for single-step immobilization of hyperthermophilic enzymes}, volume={472}, ISSN={["1873-3123"]}, DOI={10.1016/j.memsci.2014.08.037}, abstractNote={We report a single-step method to immobilize hyperthermophilic enzymes within chemically crosslinked polyvinyl alcohol (PVA) nanofibrous membranes. The polymer crosslinking that entraps the enzyme within the fiber is not affected by the particular enzyme and can thus be applied to any enzyme. Using a reactive electrospinning process, the chemical crosslinking that occurs during processing effectively entraps the enzyme within the fiber preventing enzyme leaching at elevated temperature establishing that the system is sufficiently robust for immobilization of hyperthermophilic enzymes. Upon immobilization, the enzyme retains 20% of its catalytic activity as well as its hyperthermophilicity, as the maximum activity occurs at ~90 °C, and that activity at 90 °C is an order of magnitude higher than at 37 °C. Furthermore, thermostability of the enzyme is enhanced upon immobilization as indicated by the 2-fold increase in half-life at 90 °C and pH 5.5 which extends the use of these biocatalysts at high temperatures. Compared to alternative methods, the apparent activity using the single-step method is significantly higher than alternative two-step methods (4 orders of magnitude higher than non-solvent based crosslinking and 3-fold higher than vapor-phase crosslinking). Analysis of this immobilization method indicates that the apparent decrease in specific activity could be attributed to enzyme deactivation arising from the crosslinking reaction, whereas mass transfer limits the apparent activity using alternative two-step immobilization methods. Based on this understanding, enzyme activity upon immobilization may be improved by using enzymes with higher intrinsic stability. Since significant enzyme activity is observed upon immobilization and the stability under high temperatures is enhanced, this versatile approach leverages the unique properties of hyperthermophilc enzymes and electrospun nanofibers providing a platform to produce catalytically active nanofibrous membranes appropriate for high temperature processes.}, journal={JOURNAL OF MEMBRANE SCIENCE}, author={Tang, Christina and Saquing, Carl D. and Sarin, Pooja K. and Kelly, Robert M. and Khan, Saad A.}, year={2014}, month={Dec}, pages={251–260} }
 @article{canbolat_gera_tang_monian_rao_pourdeyhimi_khan_2013, title={Preservation of Cell Viability and Protein Conformation on Immobilization within Nanofibers via Electrospinning Functionalized Yeast}, volume={5}, ISSN={["1944-8252"]}, DOI={10.1021/am4022768}, abstractNote={We investigate the immobilization of a model system of functionalized yeast that surface-display enhanced green fluorescent protein (eGFP) within chemically crosslinked polyvinyl alcohol (PVA) nanofibers. Yeast is incorporated into water insoluble nanofibrous materials by direct electrospinning with PVA followed by vapor phase chemical crosslinking of the polymer. Incorporation of yeast into the fibers is confirmed by elemental analysis and the viability is indicated by live/dead staining. Following electrospinning and crosslinking, we confirm that the yeast maintains its viability as well as the ability to express eGFP in the correct conformation. This method of processing functionalized yeast may thus be a powerful tool in the direct immobilization of properly folded, active enzymes within electrospun nanofibers with potential applications in biocatalysis.}, number={19}, journal={ACS APPLIED MATERIALS & INTERFACES}, author={Canbolat, M. Fatih and Gera, Nimish and Tang, Christina and Monian, Brinda and Rao, Balaji M. and Pourdeyhimi, Behnam and Khan, Saad A.}, year={2013}, month={Oct}, pages={9349–9354} }
 @article{canbolat_tang_bernacki_pourdeyhimi_khan_2011, title={Mammalian Cell Viability in Electrospun Composite Nanofiber Structures}, volume={11}, ISSN={["1616-5195"]}, DOI={10.1002/mabi.201100108}, abstractNote={Incorporation of mammalian cells into nanofibers (cell electrospinning) and multilayered cell-nanofiber structures (cell layering) via electrospinning are promising techniques for tissue engineering applications. We investigate the viability of 3T3-L1 mouse fibroblasts after incorporation into poly(vinyl alcohol) nanofibers and multilayering with poly(caprolactone) nanofibers and analyze the possible factors that affect cell viability. We observe that cells do not survive cell electrospinning but survive cell layering. Assessing the factors involved in cell electrospinning, we find that dehydration and fiber stretching are the main causes of cell death. In cell layering, the choice of solvent is critical, as residual solvent in the electrospun fibers could be detrimental to the cells.}, number={10}, journal={MACROMOLECULAR BIOSCIENCE}, author={Canbolat, Mehmet Fatih and Tang, Christina and Bernacki, Susan H. and Pourdeyhimi, Behnam and Khan, Saad}, year={2011}, month={Oct}, pages={1346–1356} }
 @article{saquing_tang_monian_bonino_manasco_alsberg_khan, title={Alginate-polyethylene oxide blend nanofibers and the role of the carrier polymer in electrospinning}, volume={52}, number={26}, journal={Industrial & Engineering Chemistry Research}, author={Saquing, C. D. and Tang, C. and Monian, B. and Bonino, C. A. and Manasco, J. L. and Alsberg, E. and Khan, S. A.}, pages={8692–8704} }
 @article{manasco_saquing_tang_khan, title={Cyclodextrin fibers via polymer-free electrospinning}, volume={2}, number={9}, journal={RSC Advances}, author={Manasco, J. L. and Saquing, C. D. and Tang, C. and Khan, S. A.}, pages={3778–3784} }
 @article{tang_ozcam_stout_khan, title={Effect of pH on protein distribution in electrospun PVA/BSA composite nanofibers}, volume={13}, number={5}, journal={Biomacromolecules}, author={Tang, C. and Ozcam, A. E. and Stout, B. and Khan, S. A.}, pages={1269–1278} }
 @article{higham_tang_landry_pridgeon_lee_andrady_khan, title={Foam electrospinning: A multiple jet, needle-less process for nanofiber production}, volume={60}, number={4}, journal={AIChE Journal}, author={Higham, A. K. and Tang, C. and Landry, A. M. and Pridgeon, M. C. and Lee, E. M. and Andrady, A. L. and Khan, S. A.}, pages={1355–1364} }
 @article{manasco_tang_burns_saquing_khan, title={Rapidly dissolving poly(vinyl alcohol)/cyclodextrin electrospun nanofibrous membranes}, volume={4}, number={26}, journal={RSC Advances}, author={Manasco, J. L. and Tang, C. and Burns, N. A. and Saquing, C. D. and Khan, S. A.}, pages={13274–13279} }