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Nguyen AK, Narayan RJ. Liquid-Phase Laser Induced Forward Transfer for Complex Organic Inks and Tissue Engineering. Ann Biomed Eng 2016; 45:84-99. [PMID: 27090894 DOI: 10.1007/s10439-016-1617-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2016] [Accepted: 04/09/2016] [Indexed: 01/17/2023]
Abstract
Laser induced forward transfer (LIFT) acts as a novel alternative to incumbent plotting techniques such as inkjet printing due to its ability to precisely deposit and position picoliter-sized droplets while being gentle enough to preserve sensitive structures within the ink. Materials as simple as screen printing ink to complex eukaryotic cells have been printed with applications spanning from microelectronics to tissue engineering. Biotechnology can benefit from this technique due to the efficient use of low volumes of reagent and the compatibility with a wide range of rheological properties. In addition, LIFT can be performed in a simple lab environment, not requiring vacuum or other extreme conditions. Although the basic apparatus is simple, many strategies exist to optimize the performance considering the ink and the desired pattern. The basic mechanism is similar between studies so the large number of variants can be summarized into a couple of categories and reported on with respect to their specific applications. In particular, precise and gentle deposition of complex molecules and eukaryotic cells represent the unique abilities of this technology. LIFT has demonstrated not only marked improvements in the quality of sensors and related medical devices over those manufactured with incumbent technologies but also great applicability in tissue engineering due to the high viability of printed cells.
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Pandey PC, Pandey G, Narayan RJ. Controlled synthesis of polyethylenimine coated gold nanoparticles: Application in glutathione sensing and nucleotide delivery. J Biomed Mater Res B Appl Biomater 2016; 105:1191-1199. [PMID: 27059517 DOI: 10.1002/jbm.b.33647] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2015] [Revised: 02/01/2016] [Accepted: 02/12/2016] [Indexed: 11/08/2022]
Abstract
Synthesis of functional gold nanoparticles (AuNPs) justifying selectivity in biochemical interaction along with biocompatibility suited for in vivo biomedical applications has been a challenging issue. We report herein the role of polyethylenimine (PEI) in controlled synthesis of AuNPs under ambient conditions which has potentiality for sensing glutathione and selective interaction with DNA binding proteins facilitating endosomal escape for the nucleotide delivery. The choice of organic reducing agents like formaldehyde/acetaldehyde/acetyl acetone/tetrahydrofuran hydroperoxide and other similar compounds allow rapid conversion of PEI capped gold cations into AuNPs at room temperature thus controlling the functional ability of nanoparticles as a function of organic reducing agents. Both small and higher molecular weight PEI facilitates fast synthesis of AuNPs controlling cytotoxicity during in vivo biomedical applications. The AuNPs have been characterized by UV-Vis and transmission electron microscopy revealing excellent polycrystallinity and controlled nanogeometry. The cationic polymer coating enhances the electrocatalytic performances of nanoparticles. The typical biomedical application on glutathione (GSH) sensing based on peroxidase mimetic ability of as made AuNPs is studied. The as synthesized AuNPs are extreme salt and pH resistant and have potentiality for both homogeneous and heterogeneous biocatalysis. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 1191-1199, 2017.
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Boehm RD, Jaipan P, Yang KH, Stewart TN, Narayan RJ. Microstereolithography-fabricated microneedles for fluid sampling of histamine-contaminated tuna. Int J Bioprint 2016. [DOI: 10.18063/ijb.2016.01.010] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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Miller PR, Narayan RJ, Polsky R. Microneedle-based sensors for medical diagnosis. J Mater Chem B 2016; 4:1379-1383. [DOI: 10.1039/c5tb02421h] [Citation(s) in RCA: 82] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The field of microneedle sensors is reviewed discussing current trends and future applications.
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Petrochenko PE, Kumar G, Fu W, Zhang Q, Zheng J, Liang C, Goering PL, Narayan RJ. Nanoporous Aluminum Oxide Membranes Coated with Atomic Layer Deposition-Grown Titanium Dioxide for Biomedical Applications: An In Vitro Evaluation. J Biomed Nanotechnol 2015; 11:2275-85. [DOI: 10.1166/jbn.2015.2169] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Miller PR, Boehm RD, Skoog SA, Edwards TL, Rodriguez M, Brozik S, Brener I, Byrd T, Baca JT, Ashley C, Narayan RJ, Polsky R. Electrodeposited Iron as a Biocompatible Material for Microneedle Fabrication. ELECTROANAL 2015. [DOI: 10.1002/elan.201500199] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
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57
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Petrochenko PE, Torgersen J, Gruber P, Hicks LA, Zheng J, Kumar G, Narayan RJ, Goering PL, Liska R, Stampfl J, Ovsianikov A. Laser 3D printing with sub-microscale resolution of porous elastomeric scaffolds for supporting human bone stem cells. Adv Healthc Mater 2015; 4:739-47. [PMID: 25522214 DOI: 10.1002/adhm.201400442] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2014] [Revised: 11/23/2014] [Indexed: 01/10/2023]
Abstract
A reproducible method is needed to fabricate 3D scaffold constructs that results in periodic and uniform structures with precise control at sub-micrometer and micrometer length scales. In this study, fabrication of scaffolds by two-photon polymerization (2PP) of a biodegradable urethane and acrylate-based photoelastomer is demonstrated. This material supports 2PP processing with sub-micrometer spatial resolution. The high photoreactivity of the biophotoelastomer permits 2PP processing at a scanning speed of 1000 mm s(-1), facilitating rapid fabrication of relatively large structures (>5 mm(3)). These structures are custom printed for in vitro assay screening in 96-well plates and are sufficiently flexible to enable facile handling and transplantation. These results indicate that stable scaffolds with porosities of greater than 60% can be produced using 2PP. Human bone marrow stromal cells grown on 3D scaffolds exhibit increased growth and proliferation compared to smooth 2D scaffold controls. 3D scaffolds adsorb larger amounts of protein than smooth 2D scaffolds due to their larger surface area; the scaffolds also allow cells to attach in multiple planes and to completely infiltrate the porous scaffolds. The flexible photoelastomer material is biocompatible in vitro and is associated with facile handling, making it a viable candidate for further study of complex 3D-printed scaffolds.
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Petrochenko PE, Zhang Q, Bayati R, Skoog SA, Phillips KS, Kumar G, Narayan RJ, Goering PL. Cytotoxic evaluation of nanostructured zinc oxide (ZnO) thin films and leachates. Toxicol In Vitro 2014; 28:1144-52. [DOI: 10.1016/j.tiv.2014.05.004] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2014] [Revised: 04/17/2014] [Accepted: 05/09/2014] [Indexed: 01/26/2023]
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Nguyen AK, Gittard SD, Koroleva A, Schlie S, Gaidukeviciute A, Chichkov BN, Narayan RJ. Two-photon polymerization of polyethylene glycol diacrylate scaffolds with riboflavin and triethanolamine used as a water-soluble photoinitiator. Regen Med 2014; 8:725-38. [PMID: 24147528 DOI: 10.2217/rme.13.60] [Citation(s) in RCA: 63] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
AIM In this study, the suitability of a mixture containing riboflavin (vitamin B2) and triethanolamine (TEOHA) as a novel biocompatible photoinitiator for two-photon polymerization (2PP) processing was investigated. MATERIALS & METHODS Polyethylene glycol diacrylate was crosslinked using Irgacure(®) 369, Irgacure 2959 or a riboflavin-TEOHA mixture; biocompatibility of the photopolymer extract solutions was subsequently assessed via endothelial cell proliferation assay, endothelial cell viability assay and single-cell gel electrophoresis (comet) assay. Use of a riboflavin-TEOHA mixture as a photoinitiator for 2PP processing of a tissue engineering scaffold and subsequent seeding of this scaffold with GM-7373 bovine aortic endothelial cells was also demonstrated. RESULTS The riboflavin-TEOHA mixture was found to produce much more biocompatible scaffolds than those produced with Irgacure 369 or Irgacure 2959. CONCLUSION The results suggest that riboflavin is a promising component of photoinitiators for 2PP fabrication of tissue engineering scaffolds and other medically relevant structures (e.g., biomicroelectromechanical systems).
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Skoog SA, Goering PL, Narayan RJ. Stereolithography in tissue engineering. JOURNAL OF MATERIALS SCIENCE. MATERIALS IN MEDICINE 2014; 25:845-856. [PMID: 24306145 DOI: 10.1007/s10856-013-5107-y] [Citation(s) in RCA: 150] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/09/2013] [Accepted: 11/22/2013] [Indexed: 06/02/2023]
Abstract
Several recent research efforts have focused on use of computer-aided additive fabrication technologies, commonly referred to as additive manufacturing, rapid prototyping, solid freeform fabrication, or three-dimensional printing technologies, to create structures for tissue engineering. For example, scaffolds for tissue engineering may be processed using rapid prototyping technologies, which serve as matrices for cell ingrowth, vascularization, as well as transport of nutrients and waste. Stereolithography is a photopolymerization-based rapid prototyping technology that involves computer-driven and spatially controlled irradiation of liquid resin. This technology enables structures with precise microscale features to be prepared directly from a computer model. In this review, use of stereolithography for processing trimethylene carbonate, polycaprolactone, and poly(D,L-lactide) poly(propylene fumarate)-based materials is considered. In addition, incorporation of bioceramic fillers for fabrication of bioceramic scaffolds is reviewed. Use of stereolithography for processing of patient-specific implantable scaffolds is also discussed. In addition, use of photopolymerization-based rapid prototyping technology, known as two-photon polymerization, for production of tissue engineering scaffolds with smaller features than conventional stereolithography technology is considered.
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Xiao X, Miller PR, Narayan RJ, Brozik SM, Wheeler DR, Brener I, Wang J, Burckel DB, Polsky R. Simultaneous Detection of Dopamine, Ascorbic Acid and Uric Acid at Lithographically-Defined 3D Graphene Electrodes. ELECTROANAL 2013. [DOI: 10.1002/elan.201300253] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Petrochenko PE, Skoog SA, Zhang Q, Comstock DJ, Elam JW, Goering PL, Narayan RJ. Cytotoxicity of cultured macrophages exposed to antimicrobial zinc oxide (ZnO) coatings on nanoporous aluminum oxide membranes. BIOMATTER 2013; 3:25528. [PMID: 23881040 PMCID: PMC3749283 DOI: 10.4161/biom.25528] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Zinc oxide (ZnO) is a widely used commercial material that is finding use in wound healing applications due to its antimicrobial properties. Our study demonstrates a novel approach for coating ZnO with precise thickness control onto 20 nm and 100 nm pore diameter anodized aluminum oxide using atomic layer deposition (ALD). ZnO was deposited throughout the nanoporous structure of the anodized aluminum oxide membranes. An 8 nm-thick coating of ZnO, previously noted to have antimicrobial properties, was cytotoxic to cultured macrophages. After 48 h, ZnO-coated 20 nm and 100 nm pore anodized aluminum oxide significantly decreased cell viability by ≈65% and 54%, respectively, compared with cells grown on uncoated anodized aluminum oxide membranes and cells grown on tissue culture plates. Pore diameter (20–200 nm) did not influence cell viability.
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Gittard SD, Chen B, Xu H, Ovsianikov A, Chichkov BN, Monteiro-Riviere NA, Narayan RJ. The Effects of Geometry on Skin Penetration and Failure of Polymer Microneedles. JOURNAL OF ADHESION SCIENCE AND TECHNOLOGY 2013; 27:227-243. [PMID: 23543070 PMCID: PMC3610923 DOI: 10.1080/01694243.2012.705101] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Microneedles are small-scale devices that may be used for drug delivery and biosensing. In this study, the forces required for mechanical failure, the modes of mechanical failure, as well as the mechanisms for microneedle penetration into porcine skin were examined. Microneedles produced from the acrylate-based polymer e-Shell 200 using an indirect rapid prototyping approach involving two-photon polymerization and poly(dimethylsiloxane) micromolding were found to possess sufficient strength for penetration of porcine skin. The failure forces were an order of magnitude greater than the forces necessary for full insertion into the skin. Bending was the most common form of failure; an increasing aspect ratio and a decreasing tip diameter were associated with lower failure forces. Video captured during skin penetration revealed that microneedle penetration into the skin occurred by means of a series of insertions and not by means of a single insertion event. Images obtained during and after skin penetration confirmed microneedle penetration of skin as well as transdermal delivery of lucifer yellow dye. These findings shed insight into the mechanisms of microneedle penetration and failure, facilitating design improvements for polymer microneedles.
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Meredith JR, Jin C, Narayan RJ, Aggarwal R. Biomedical applications of carbon-nanotube composites. Front Biosci (Elite Ed) 2013; 5:610-21. [PMID: 23277017 DOI: 10.2741/e643] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The unique physical, chemical and mechanical properties of carbon nanotubes make them attractive for a variety of biomedical applications. Carbon nanotubes have been used to modify conventional biomedical materials to enhance mechanical properties, biocompatibility, or to impart other functionalities. New multifunctional composite materials using carbon nanotubes have been developed by combining them with inorganic, polymeric or biological materials. The biomedical applications for which novel carbon nanotube composites have been investigated include antimicrobial coatings, neural implants, tissue engineering scaffolds and electrochemical biosensors. In this paper, research on development and application of carbon nanotube composites for biomedical applications has been reviewed.
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Bayati MR, Ding J, Lee YF, Narayan RJ, Narayan J, Zhou H, Pennycook SJ. Defect mediated photocatalytic decomposition of 4-chlorophenol on epitaxial rutile thin films under visible and UV illumination. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2012; 24:395005. [PMID: 22941905 DOI: 10.1088/0953-8984/24/39/395005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
We show that pure rutile TiO(2) can be photo-responsive even under low energy visible light after annealing in vacuum where we envisage that the point defects, i.e. oxygen vacancies and titanium interstitials, serve an important role. In this study, single crystal rutile films were grown by the pulsed laser deposition technique and then vacuum annealed under different oxygen pressures to introduce defects into their lattices. 4-chlorophenol was selected as a model material and decomposed by the annealed TiO(2) films where the maximum photocatalytic reaction rate constants were determined as 0.0107 and 0.0072 min(-1) under UV and visible illumination. Epitaxial growth along the [200] direction was confirmed by φ-scan and 2θ-scan XRD and the epitaxial relationship between the rutile film and the c-sapphire substrate was explained as (100)[010](R) [parallel] (0001)[12[combining overline]10](S). The formation of atomically sharp interfaces and the epitaxial growth were ascertained by annular dark-field STEM imaging. Based on the XPS, UV-vis and PL spectroscopy results, it was found that the defect concentration increased after annealing under lower pressures, e.g. 5 × 10(-6) Torr. In contrast, more perfect crystals were obtained when the films were annealed under high oxygen pressures, namely 5 × 10(1) Torr. The morphology of the films was also investigated by employing an AFM technique. It was observed that increase of the annealing pressure results in the formation of larger grains. It was also found that the electrical resistivity of the rutile films strongly increased by about three orders of magnitude when the annealing pressure increased from 5 × 10(-4) to 5 × 10(1) Torr.
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Miller PR, Skoog SA, Edwards TL, Wheeler DR, Xiao X, Brozik SM, Polsky R, Narayan RJ. Hollow microneedle-based sensor for multiplexed transdermal electrochemical sensing. J Vis Exp 2012:e4067. [PMID: 22688693 PMCID: PMC3471292 DOI: 10.3791/4067] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
The development of a minimally invasive multiplexed monitoring system for rapid analysis of biologically-relevant molecules could offer individuals suffering from chronic medical conditions facile assessment of their immediate physiological state. Furthermore, it could serve as a research tool for analysis of complex, multifactorial medical conditions. In order for such a multianalyte sensor to be realized, it must be minimally invasive, sampling of interstitial fluid must occur without pain or harm to the user, and analysis must be rapid as well as selective. Initially developed for pain-free drug delivery, microneedles have been used to deliver vaccines and pharmacologic agents (e.g., insulin) through the skin. Since these devices access the interstitial space, microneedles that are integrated with microelectrodes can be used as transdermal electrochemical sensors. Selective detection of glucose, glutamate, lactate, hydrogen peroxide, and ascorbic acid has been demonstrated using integrated microneedle-electrode devices with carbon fibers, modified carbon pastes, and platinum-coated polymer microneedles serving as transducing elements. This microneedle sensor technology has enabled a novel and sophisticated analytical approach for in situ and simultaneous detection of multiple analytes. Multiplexing offers the possibility of monitoring complex microenvironments, which are otherwise difficult to characterize in a rapid and minimally invasive manner. For example, this technology could be utilized for simultaneous monitoring of extracellular levels of, glucose, lactate and pH, which are important metabolic indicators of disease states (e.g., cancer proliferation) and exercise-induced acidosis.
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Boehm RD, Miller PR, Singh R, Shah A, Stafslien S, Daniels J, Narayan RJ. Indirect rapid prototyping of antibacterial acid anhydride copolymer microneedles. Biofabrication 2012; 4:011002. [PMID: 22287512 DOI: 10.1088/1758-5082/4/1/011002] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Microneedles are needle-like projections with microscale features that may be used for transdermal delivery of a variety of pharmacologic agents, including antibacterial agents. In the study described in this paper, an indirect rapid prototyping approach involving a combination of visible light dynamic mask micro-stereolithography and micromolding was used to prepare microneedle arrays out of a biodegradable acid anhydride copolymer, Gantrez(®) AN 169 BF. Fourier transform infrared spectroscopy, energy dispersive x-ray spectrometry and nanoindentation studies were performed to evaluate the chemical and mechanical properties of the Gantrez(®) AN 169 BF material. Agar plating studies were used to evaluate the in vitro antimicrobial performance of these arrays against Bacillus subtilis, Candida albicans, Enterococcus faecalis, Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus. Large zones of growth inhibition were noted for Escherichia coli, S. aureus, Enterococcus faecalis and B. subtilis. The performance of Gantrez(®) AN 169 BF against several bacteria suggests that biodegradable acid anhydride copolymer microneedle arrays prepared using visible light dynamic mask micro-stereolithography micromolding may be useful for treating a variety of skin infections.
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Webster TJ, Yao C, Lu J, Allhoff F, Facchini D, Martin TM, Robinson DB, Narayan RJ, Choudhury P, Agrawal D, Pareta RA, Sirivisoot S, Sirivisoot S, Pareta RA, Tran PA, Webster TJ, Santos HA, Bimbo LM, Neves JD, Sarmento B, Yu H, Chen Y, Coughlin AJ, West JL, van Heeren H, Willander M, Nur O, Oseni AO, Seifalian AM, Wang H, Fu X, Mikael PE, Wallace JA, Nukavarapu SP, Alsbaiee A, Beingessner R, Fenniri H, Kumar Dubey A, Balani K, Basu B, Zhang LG, Li J, Lee JD, Musib M, Saha S, Lock J, Liu H. Contributor contact details. Nanomedicine (Lond) 2012. [DOI: 10.1016/b978-0-85709-233-5.50024-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022] Open
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Gittard SD, Nguyen A, Obata K, Koroleva A, Narayan RJ, Chichkov BN. Fabrication of microscale medical devices by two-photon polymerization with multiple foci via a spatial light modulator. BIOMEDICAL OPTICS EXPRESS 2011; 2:3167-78. [PMID: 22076276 PMCID: PMC3207384 DOI: 10.1364/boe.2.003167] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/08/2011] [Revised: 10/07/2011] [Accepted: 10/09/2011] [Indexed: 05/20/2023]
Abstract
Two-photon polymerization is an appealing technique for producing microscale devices due to its flexibility in producing structures with a wide range of geometries as well as its compatibility with materials suitable for biomedical applications. The greatest limiting factor in widespread use of two-photon polymerization is the slow fabrication times associated with line-by-line, high-resolution structuring. In this study, a recently developed technology was used to produce microstructures by two-photon polymerization with multiple foci, which significantly reduces the production time. Computer generated hologram pattern technology was used to generate multiple laser beams in controlled positions from a single laser. These multiple beams were then used to simultaneously produce multiple microstructures by two-photon polymerization. Arrays of micro-Venus structures, tissue engineering scaffolds, and microneedle arrays were produced by multifocus two-photon polymerization. To our knowledge, this work is the first demonstration of multifocus two-photon polymerization technology for production of a functional medical device. Multibeam fabrication has the potential to greatly improve the efficiency of two-photon polymerization production of microscale devices such as tissue engineering scaffolds and microneedle arrays.
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Petrochenko P, Narayan RJ. Novel approaches to bone grafting: porosity, bone morphogenetic proteins, stem cells, and the periosteum. J Long Term Eff Med Implants 2011; 20:303-15. [PMID: 21488823 DOI: 10.1615/jlongtermeffmedimplants.v20.i4.50] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
The disadvantages involving the use of a patient's own bone as graft material have led surgeons to search for alternative materials. In this review, several characteristics of a successful bone graft material are discussed. In addition, novel synthetic materials and natural bone graft materials are being considered. Various factors can determine the success of a bone graft substitute. For example, design considerations such as porosity, pore shape, and interconnection play significant roles in determining graft performance. The effective delivery of bone morphogenetic proteins and the ability to restore vascularization also play significant roles in determining the success of a bone graft material. Among current approaches, shorter bone morphogenetic protein sequences, more efficient delivery methods, and periosteal graft supplements have shown significant promise for use in autograft substitutes or autograft extenders.
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Boehm RD, Miller PR, Hayes SL, Monteiro-Riviere NA, Narayan RJ. Modification of microneedles using inkjet printing. AIP ADVANCES 2011; 1:22139. [PMID: 22125759 PMCID: PMC3217292 DOI: 10.1063/1.3602461] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/15/2011] [Accepted: 05/28/2011] [Indexed: 05/28/2023]
Abstract
In this study, biodegradable acid anhydride copolymer microneedles containing quantum dots were fabricated by means of visible light dynamic mask micro-stereolithography-micromolding and inkjet printing. Nanoindentation was performed to obtain the hardness and the Young's modulus of the biodegradable acid anhydride copolymer. Imaging of quantum dots within porcine skin was accomplished by means of multiphoton microscopy. Our results suggest that the combination of visible light dynamic mask micro-stereolithography-micromolding and inkjet printing enables fabrication of solid biodegradable microneedles with a wide range of geometries as well as a wide range of pharmacologic agent compositions.
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Hyde GK, Stewart SM, Scarel G, Parsons GN, Shih CC, Shih CM, Lin SJ, Su YY, Monteiro-Riviere NA, Narayan RJ. Atomic layer deposition of titanium dioxide on cellulose acetate for enhanced hemostasis. Biotechnol J 2011; 6:213-23. [PMID: 21298806 DOI: 10.1002/biot.201000342] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
TiO₂ films may be used to alter the wettability and hemocompatibility of cellulose materials. In this study, pure and stoichiometric TiO₂ films were grown using atomic layer deposition on both silicon and cellulose substrates. The films were grown with uniform thicknesses and with a growth rate in agreement with literature results. The TiO₂ films were shown to profoundly alter the water contact angle values of cellulose in a manner dependent upon processing characteristics. Higher amounts of protein adsorption indicated by blurry areas on images generated by scanning electron microscopy were noted on TiO₂ -coated cellulose acetate than on uncoated cellulose acetate. These results suggest that atomic layer deposition is an appropriate method for improving the biological properties of hemostatic agents and other blood-contacting biomaterials.
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Miller PR, Gittard SD, Edwards TL, Lopez DM, Xiao X, Wheeler DR, Monteiro-Riviere NA, Brozik SM, Polsky R, Narayan RJ. Integrated carbon fiber electrodes within hollow polymer microneedles for transdermal electrochemical sensing. BIOMICROFLUIDICS 2011; 5:13415. [PMID: 21522504 PMCID: PMC3082351 DOI: 10.1063/1.3569945] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2011] [Accepted: 03/02/2011] [Indexed: 05/04/2023]
Abstract
In this study, carbon fiber electrodes were incorporated within a hollow microneedle array, which was fabricated using a digital micromirror device-based stereolithography instrument. Cell proliferation on the acrylate-based polymer used in microneedle fabrication was examined with human dermal fibroblasts and neonatal human epidermal keratinocytes. Studies involving full-thickness cadaveric porcine skin and trypan blue dye demonstrated that the hollow microneedles remained intact after puncturing the outermost layer of cadaveric porcine skin. The carbon fibers underwent chemical modification in order to enable detection of hydrogen peroxide and ascorbic acid; electrochemical measurements were demonstrated using integrated electrode-hollow microneedle devices.
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McCullen SD, Miller PR, Gittard SD, Gorga RE, Pourdeyhimi B, Narayan RJ, Loboa EG. In situ collagen polymerization of layered cell-seeded electrospun scaffolds for bone tissue engineering applications. Tissue Eng Part C Methods 2011; 16:1095-105. [PMID: 20192901 DOI: 10.1089/ten.tec.2009.0753] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Electrospun scaffolds have been studied extensively for their potential use in bone tissue engineering applications. However, inherent issues with the electrospinning approach limit the thickness of these scaffolds and constrain their use for repair of critical-sized bone defects. One method to increase overall scaffold thickness is to bond multiple electrospun scaffolds together with a biocompatible gel. The objective of this study was to determine whether multiple human adipose-derived stem cell (hASC-seeded electrospun, nanofibrous scaffolds could be layered via in situ collagen assembly and whether the addition of laser-ablated micron-sized pores within the electrospun scaffold layers was beneficial to the bonding process. Pores were created by a laser ablation technique. We hypothesized that the addition of micron-sized pores within the electrospun scaffolds would encourage collagen integration between scaffold layers, and promote osteogenic differentiation of hASCs seeded within the layered electrospun scaffolds. To evaluate the benefit of assembled scaffolds with and without engineered pores, hASCs were seeded on individual electrospun scaffolds, hASC-seeded scaffolds were bonded with type I collagen, and the assembled ∼3-mm-thick constructs were cultured for 3 weeks to examine their potential as bone tissue engineering scaffolds. Assembled electrospun scaffolds/collagen gel constructs using electrospun scaffolds with pores resulted in enhanced hASC viability, proliferation, and mineralization of the scaffolds after 3 weeks in vitro compared to constructs using electrospun scaffolds without pores. Scanning electron microscopy and histological examination revealed that the assembled constructs that included laser-ablated electrospun scaffolds were able to maintain a contracted structure and were not delaminated, unlike assembled constructs containing nonablated electrospun scaffolds. This is the first study to show that the introduction of engineered pores in electrospun scaffolds assists with multilayered scaffold integration, resulting in thick constructs potentially suitable for use as scaffolds for bone tissue engineering or repair of critical bone defects.
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