@article{yang_joshi_rodenhausen_sumant_skoog_narayan_2021, title={Correlation of zeta potential and contact angle of oxygen and fluorine terminated nitrogen incorporated ultrananocrystalline diamond (N UNCD) thin films}, volume={295}, ISSN={["1873-4979"]}, DOI={10.1016/j.matlet.2021.129823}, abstractNote={• Surface chemistry of N-incorporated UNCD was altered by oxygen and fluorine plasma treatments. • O-termination rendered the surface hydrophilic. • O-termination shifted the zeta potential to less negative values at high pH values and was less sensitive to changes in pH. • F-termination rendered the surface more hydrophobic and shifted the zeta potential to more negative values. • The F-terminated UNCD experienced a more significant change of zeta potential across the pH range. The surface chemistry of nitrogen incorporated ultrananocrystalline diamond (N-UNCD) films was altered by plasma treatment utilizing oxygen and fluorine plasma chemistries; the modified N-UNCD surfaces were characterized using contact angle and zeta potential measurements to give a more complete understanding of the interactions between the solid surface and the aqueous solution. The bonding character, surface composition, and morphology of the N-UNCD films before and after surface treatment were also monitored using X-ray photoelectron spectroscopy, atomic force microscopy, and Raman spectroscopy to ensure the grafting of functional groups; the contributing factor to the results was purely from the surface termination.}, journal={MATERIALS LETTERS}, author={Yang, Kai-Hung and Joshi, Pratik and Rodenhausen, Keith B. and Sumant, Anirudha V. and Skoog, Shelby A. and Narayan, Roger J.}, year={2021}, month={Jul} }
 @misc{yang_boehm_skoog_narayan_2020, title={Nanostructured Medical Adhesives}, volume={16}, ISSN={["1550-7041"]}, DOI={10.1166/jbn.2020.2897}, abstractNote={Suturing has been the gold standard approach to close wounds for many decades. However, suturing causes tissue damage, which is accompanied by foreign body reaction, entry of pathogens, complications, infection, or death. In addition, the procedure is usually time-consuming, requiring manual dexterity and free moving space. Other adhesive approaches have been proposed and demonstrated with great potential, including laser-assisted tissue closure with either photothermal or photochemical reactions, application of nanoparticles, glues, constructs based on extracellular matrix (ECM), microbarbs, bio-inspired structures, and tape. The quality of closure has been evaluated by histological methods, indexing, morphology, tensile testing, patency rate, leakage pressure, and burst pressure. All the novel tissue joining methods aim to provide an adhesive with appropriate strength, non-cytotoxicity, and minimal damage. The capability for rapid attachment and release may further reduce surgical procedure time. More research is needed to prove the feasibility of new tissue joining techniques based on the type of tissue, surface chemistry, and working environment.}, number={3}, journal={JOURNAL OF BIOMEDICAL NANOTECHNOLOGY}, author={Yang, Kai-Hung and Boehm, Ryan D. and Skoog, Shelby A. and Narayan, Roger J.}, year={2020}, month={Mar}, pages={263–282} }
 @misc{pandey_shukla_skoog_boehm_narayan_2019, title={Current Advancements in Transdermal Biosensing and Targeted Drug Delivery}, volume={19}, ISSN={["1424-8220"]}, DOI={10.3390/s19051028}, abstractNote={In this manuscript, recent advancements in the area of minimally-invasive transdermal biosensing and drug delivery are reviewed. The administration of therapeutic entities through the skin is complicated by the stratum corneum layer, which serves as a barrier to entry and retards bioavailability. A variety of strategies have been adopted for the enhancement of transdermal permeation for drug delivery and biosensing of various substances. Physical techniques such as iontophoresis, reverse iontophoresis, electroporation, and microneedles offer (a) electrical amplification for transdermal sensing of biomolecules and (b) transport of amphiphilic drug molecules to the targeted site in a minimally invasive manner. Iontophoretic delivery involves the application of low currents to the skin as well as the migration of polarized and neutral molecules across it. Transdermal biosensing via microneedles has emerged as a novel approach to replace hypodermic needles. In addition, microneedles have facilitated minimally invasive detection of analytes in body fluids. This review considers recent innovations in the structure and performance of transdermal systems.}, number={5}, journal={SENSORS}, author={Pandey, Prem C. and Shukla, Shubhangi and Skoog, Shelby A. and Boehm, Ryan D. and Narayan, Roger J.}, year={2019}, month={Mar} }
 @article{skoog_lu_malinauskas_sumant_zheng_goering_narayan_casey_2017, title={Effects of nanotopography on the in vitro hemocompatibility of nanocrystalline diamond coatings}, volume={105}, ISSN={["1552-4965"]}, DOI={10.1002/jbm.a.35872}, abstractNote={Nanocrystalline diamond (NCD) coatings have been investigated for improved wear resistance and enhanced hemocompatibility of cardiovascular devices. The goal of this study was to evaluate the effects of NCD surface nanotopography on in vitro hemocompatibility. NCD coatings with small (NCD-S) and large (NCD-L) grain sizes were deposited using microwave plasma chemical vapor deposition and characterized using scanning electron microscopy, atomic force microscopy, contact angle testing, and Raman spectroscopy. NCD-S coatings exhibited average grain sizes of 50-80 nm (RMS 5.8 nm), while NCD-L coatings exhibited average grain sizes of 200-280 nm (RMS 23.1 nm). In vitro hemocompatibility testing using human blood included protein adsorption, hemolysis, nonactivated partial thromboplastin time, platelet adhesion, and platelet activation. Both NCD coatings demonstrated low protein adsorption, a nonhemolytic response, and minimal activation of the plasma coagulation cascade. Furthermore, the NCD coatings exhibited low thrombogenicity with minimal platelet adhesion and aggregation, and similar morphological changes to surface-bound platelets (i.e., activation) in comparison to the HDPE negative control material. For all assays, there were no significant differences in the blood-material interactions of NCD-S versus NCD-L. The two tested NCD coatings, regardless of nanotopography, had similar hemocompatibility profiles compared to the negative control material (HDPE) and should be further evaluated for use in blood-contacting medical devices. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 253-264, 2017.}, number={1}, journal={JOURNAL OF BIOMEDICAL MATERIALS RESEARCH PART A}, author={Skoog, Shelby A. and Lu, Qijin and Malinauskas, Richard A. and Sumant, Anirudha V. and Zheng, Jiwen and Goering, Peter L. and Narayan, Roger J. and Casey, Brendan J.}, year={2017}, month={Jan}, pages={253–264} }
 @article{skoog_kumar_goering_williams_stiglich_narayan_2016, title={Biological Response of Human Bone Marrow-Derived Mesenchymal Stem Cells to Commercial Tantalum Coatings with Microscale and Nanoscale Surface Topographies}, volume={68}, ISSN={["1543-1851"]}, DOI={10.1007/s11837-016-1934-x}, number={6}, journal={JOM}, author={Skoog, Shelby A. and Kumar, Girish and Goering, Peter L. and Williams, Brian and Stiglich, Jack and Narayan, Roger J.}, year={2016}, month={Jun}, pages={1672–1678} }
 @article{skoog_kumar_zheng_sumant_goering_narayan_2016, title={Biological evaluation of ultrananocrystalline and nanocrystalline diamond coatings}, volume={27}, ISSN={["1573-4838"]}, DOI={10.1007/s10856-016-5798-y}, number={12}, journal={JOURNAL OF MATERIALS SCIENCE-MATERIALS IN MEDICINE}, author={Skoog, Shelby A. and Kumar, Girish and Zheng, Jiwen and Sumant, Anirudha V. and Goering, Peter L. and Narayan, Roger J.}, year={2016}, month={Dec} }
 @article{boehm_jaipan_skoog_stafslien_vanderwal_narayan_2016, title={Inkjet deposition of itraconazole onto poly(glycolic acid) microneedle arrays}, volume={11}, ISSN={["1559-4106"]}, DOI={10.1116/1.4941448}, abstractNote={Poly(glycolic acid) microneedle arrays were fabricated using a drawing lithography process; these arrays were modified with a drug release agent and an antifungal agent by piezoelectric inkjet printing. Coatings containing poly(methyl vinyl ether-co-maleic anhydride), a water-soluble drug release layer, and itraconazole (an antifungal agent), were applied to the microneedles by piezoelectric inkjet printing. Microscopic evaluation of the microneedles indicated that the modified microneedles contained the piezoelectric inkjet printing-deposited agents and that the surface coatings were released in porcine skin. Energy dispersive x-ray spectrometry aided in confirmation that the piezoelectric inkjet printing-deposited agents were successfully applied to the desired target areas of the microneedle surface. Fourier transform infrared spectroscopy was used to confirm the presence of the component materials in the piezoelectric inkjet printing-deposited material. Itraconazole-modified microneedle arrays incubated with agar plates containing Candida albicans cultures showed zones of growth inhibition.}, number={1}, journal={BIOINTERPHASES}, author={Boehm, Ryan D. and Jaipan, Panupong and Skoog, Shelby A. and Stafslien, Shane and VanderWal, Lyndsi and Narayan, Roger J.}, year={2016}, month={Mar} }
 @article{miller_boehm_skoog_edwards_rodriguez_brozik_brener_byrd_baca_ashley_et al._2015, title={Electrodeposited Iron as a Biocompatible Material for Microneedle Fabrication}, volume={27}, ISSN={["1521-4109"]}, DOI={10.1002/elan.201500199}, abstractNote={Electroplated iron was investigated as a novel material for microneedle fabrication due to its recent success as a biocompatible metal in other medical device applications. Hollow polymer microneedles were made using a laser direct write process that involved two-photon polymerization of a commercially available Class 2a biocompatible polymer and subsequent electroplating of this structure with iron. Electroplating bath and deposition conditions were shown to affect the mechanical properties of both iron plated microneedles and iron plated on planar polymer substrates. Conditions for depositing the iron coatings were investigated in terms of grain size, residual strain, and elemental composition for planar iron samples. Fracture strength and puncture mechanics into ex vivo porcine skin for iron coated hollow microneedles were examined. Biocompatibility testing was performed using the MTT assay against human epidermal keratinocytes with several concentrations of iron extract to investigate iron as a material used for transdermal applications. Iron coatings proved to significantly improve the strength of the hollow polymer microneedles and sustained structural integrity up to 7 insertions into porcine skin without bending. A commercially available device (Medtronic MiniMed Quick-Serter®) was used for controlled application of microneedles into porcine skin and estimations of insertion forces for the device were made. Plating conditions were optimized such that an adherent, uniform, and high purity iron coating was deposited onto polymer substrates and polymer microneedles without delamination or fracturing of the microneedles upon ex vivo insertion into porcine skin.}, number={9}, journal={ELECTROANALYSIS}, author={Miller, Philip R. and Boehm, Ryan D. and Skoog, Shelby A. and Edwards, Thayne L. and Rodriguez, Mark and Brozik, Susan and Brener, Igal and Byrd, Thomas and Baca, Justin T. and Ashley, Carlee and et al.}, year={2015}, month={Sep}, pages={2239–2249} }
 @article{petrochenko_zhang_bayati_skoog_phillips_kumar_narayan_goering_2014, title={Cytotoxic evaluation of nanostructured zinc oxide (ZnO) thin films and leachates}, volume={28}, ISSN={["0887-2333"]}, DOI={10.1016/j.tiv.2014.05.004}, abstractNote={Nanostructured ZnO films have potential use as coatings on medical devices and food packaging due to their antimicrobial and UV-protection properties. However, their influence on mammalian cells during clinical use is not fully understood. This study investigated the potential cytotoxicity of ZnO thin films in RAW 264.7 macrophages. ZnO thin films (∼96nm thick with a 50nm grain) were deposited onto silicon wafers using pulsed laser deposition. Cells grown directly on ZnO thin film coatings exhibited less toxicity than cells exposed to extracts of the coatings. Cells on ZnO thin films exhibited a 43% and 68% decrease in cell viability using the MTT and 7-AAD/Annexin V flow cytometry assays, respectively, after a 24-h exposure as compared to controls. Undiluted 100% 24- and 48-h extracts decreased viability by 89%, increased cell death by LDH release to 76% 24h after treatment, and increased ROS after 5-24h of exposure. In contrast, no cytotoxicity or ROS were observed for 25% and 50% extracts, indicating a tolerable concentration. Roughly 24 and 34μg/m(2) Zn leached off the surfaces after 24 and 48h of incubation, respectively. ZnO coatings may produce gradual ion release which becomes toxic after a certain level and should be evaluated using both direct exposure and extraction methods.}, number={6}, journal={TOXICOLOGY IN VITRO}, author={Petrochenko, Peter E. and Zhang, Qin and Bayati, Reza and Skoog, Shelby A. and Phillips, K. Scott and Kumar, Girish and Narayan, Roger J. and Goering, Peter L.}, year={2014}, month={Sep}, pages={1144–1152} }
 @article{divan_makarova_skoog_narayan_sumant_tang_moldovan_2014, title={High-aspect-ratio nanoporous membranes made by reactive ion etching and e-beam and interference lithography}, volume={20}, ISSN={["1432-1858"]}, DOI={10.1007/s00542-013-1932-7}, number={10-11}, journal={MICROSYSTEM TECHNOLOGIES-MICRO-AND NANOSYSTEMS-INFORMATION STORAGE AND PROCESSING SYSTEMS}, author={Divan, Ralu and Makarova, Olga V. and Skoog, Shelby and Narayan, Roger and Sumant, Anirudha V. and Tang, Cha-Mei and Moldovan, Nicolaie}, year={2014}, month={Oct}, pages={1797–1802} }
 @article{skoog_goering_narayan_2014, title={Stereolithography in tissue engineering}, volume={25}, ISSN={["1573-4838"]}, DOI={10.1007/s10856-013-5107-y}, number={3}, journal={JOURNAL OF MATERIALS SCIENCE-MATERIALS IN MEDICINE}, author={Skoog, Shelby A. and Goering, Peter L. and Narayan, Roger J.}, year={2014}, month={Mar}, pages={845–856} }
 @article{skoog_nguyen_kumar_zheng_goering_koroleva_chichkov_narayan_2014, title={Two-photon polymerization of 3-D zirconium oxide hybrid scaffolds for long-term stem cell growth}, volume={9}, ISSN={["1559-4106"]}, DOI={10.1116/1.4873688}, abstractNote={Two-photon polymerization is a technique that involves simultaneous absorption of two photons from a femtosecond laser for selective polymerization of a photosensitive material. In this study, two-photon polymerization was used for layer-by-layer fabrication of 3-D scaffolds composed of an inorganic-organic zirconium oxide hybrid material. Four types of scaffold microarchitectures were created, which exhibit layers of parallel line features at various orientations as well as pores between the line features. Long-term cell culture studies involving human bone marrow stromal cells were conducted using these 3-D scaffolds. Cellular adhesion and proliferation were demonstrated on all of the scaffold types; tissuelike structure was shown to span the pores. This study indicates that two-photon polymerization may be used to create microstructured scaffolds out of an inorganic-organic zirconium oxide hybrid material for use in 3-D tissue culture systems.}, number={2}, journal={BIOINTERPHASES}, author={Skoog, Shelby A. and Nguyen, Alexander K. and Kumar, Girish and Zheng, Jiwen and Goering, Peter L. and Koroleva, Anastasia and Chichkov, Boris N. and Narayan, Roger J.}, year={2014}, month={Jun} }
 @article{miller_skoog_edwards_lopez_wheeler_arango_xiao_brozik_wang_polsky_et al._2012, title={Multiplexed microneedle-based biosensor array for characterization of metabolic acidosis}, volume={88}, ISSN={["1873-3573"]}, DOI={10.1016/j.talanta.2011.11.046}, abstractNote={The development of a microneedle-based biosensor array for multiplexed in situ detection of exercise-induced metabolic acidosis, tumor microenvironment, and other variations in tissue chemistry is described. Simultaneous and selective amperometric detection of pH, glucose, and lactate over a range of physiologically relevant concentrations in complex media is demonstrated. Furthermore, materials modified with a cell-resistant (Lipidure(®)) coating were shown to inhibit macrophage adhesion; no signs of coating delamination were noted over a 48-h period.}, journal={TALANTA}, author={Miller, Philip R. and Skoog, Shelby A. and Edwards, Thayne L. and Lopez, Deanna M. and Wheeler, David R. and Arango, Dulce C. and Xiao, Xiaoyin and Brozik, Susan M. and Wang, Joseph and Polsky, Ronen and et al.}, year={2012}, month={Jan}, pages={739–742} }
 @misc{skoog_elam_narayan, title={Atomic layer deposition: Medical and biological applications}, volume={58}, number={2}, journal={International Materials Reviews}, author={Skoog, S. A. and Elam, J. W. and Narayan, R. J.}, pages={113–129} }
 @article{skoog_narayan, title={Stereolithography in medical device fabrication}, volume={171}, number={3}, journal={Advanced Materials & Processes}, author={Skoog, S. A. and Narayan, R. J.}, pages={32–34} }