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Lali N, Tsiatsiani L, Elffrink W, Kokke B, Satzer P, Dirksen E, Eppink M, Jungbauer A. An inert tracer: The binding site of a fluorescent dye on the antibody and its effects on Protein A chromatography. J Chromatogr A 2024; 1728:464995. [PMID: 38805895 DOI: 10.1016/j.chroma.2024.464995] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2024] [Revised: 05/10/2024] [Accepted: 05/11/2024] [Indexed: 05/30/2024]
Abstract
Fluorescently labeled antibodies are widely used to visualize the adsorption process in protein chromatography using confocal laser scanning microscopy (CLSM), but also as a tracer for determination of residence time distribution (RTD) in continuous chromatography. It is assumed that the labeled protein is inert and representative of the unlabeled antibody, ignoring the fact that labeling with a fluorescent dye can change the characteristics of the original molecule. It became evident that the fluorescently labeled antibody has a higher affinity toward protein A resins such as MabSelect Sure. This can be due to slight differences in hydrophobicity and net charge, which are caused by the addition of the fluorescent dye. However, this difference is eliminated when using high salt concentrations in the adsorption studies. In this work, the site occupancy of two labeled antibodies, MAb1 (IgG1 subclass) and MAb2 (IgG2 subclass) conjugated with the fluorescent dye Alexa Fluor™ 488 was elucidated by intact mass spectrometry (MS) and peptide mapping LC-MS/MS, employing a sequential cleavage with Endoproteinase Lys-C and trypsin and in parallel with chymotrypsin alone. It was shown that the main binding site for the dye was a specific lysine in the heavy chains of the MAb1 and MAb2 molecules, in positions 188 and 189 respectively. Other lysine residues distributed throughout the protein sequence were labeled to a lot lesser extent. The labeled antibody had a slightly different affinity to MabSelect Sure although its primary binding site (to Protein A) was not affected by labeling, despite the secondary region responsible for binding to the protein A was partly labeled. Overall, the fluorescent-labeled antibodies are a good compromise as an inert tracer in residence time distribution and chromatography studies because they are much cheaper than isotope-labeled antibodies; However, the differences between the labeled and unlabeled antibodies should be considered.
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Affiliation(s)
- Narges Lali
- ACIB- Austrian Centre of Industrial Biotechnology, Krenngasse 37, A-8010 Graz, Austria; Department of Biotechnology, University of Natural Resources and Life Sciences, Vienna, Austria
| | | | | | - Bas Kokke
- Byondis, Microweg 22, 6545 CM Nijmegen, the Netherlands
| | - Peter Satzer
- ACIB- Austrian Centre of Industrial Biotechnology, Krenngasse 37, A-8010 Graz, Austria; Department of Biotechnology, University of Natural Resources and Life Sciences, Vienna, Austria
| | - Eef Dirksen
- Byondis, Microweg 22, 6545 CM Nijmegen, the Netherlands
| | - Michel Eppink
- Byondis, Microweg 22, 6545 CM Nijmegen, the Netherlands
| | - Alois Jungbauer
- ACIB- Austrian Centre of Industrial Biotechnology, Krenngasse 37, A-8010 Graz, Austria; Department of Biotechnology, University of Natural Resources and Life Sciences, Vienna, Austria.
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2
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Phan CM, Wy Chan V, Drolle E, Hui A, Ngo W, Bose S, Shows A, Liang S, Sharma V, Subbaraman L, Zheng Y, Shi X, Wu J, Jones L. Evaluating the in vitro wettability and coefficient of friction of a novel and contemporary reusable silicone hydrogel contact lens materials using an in vitro blink model. Cont Lens Anterior Eye 2024; 47:102129. [PMID: 38423868 DOI: 10.1016/j.clae.2024.102129] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2023] [Revised: 02/09/2024] [Accepted: 02/20/2024] [Indexed: 03/02/2024]
Abstract
PURPOSE To evaluate the in vitro wettability and coefficient of friction of a novel amphiphilic polymeric surfactant (APS), poly(oxyethylene)-co-poly(oxybutylene) (PEO-PBO) releasing silicone hydrogel (SiHy) contact lens material (serafilcon A), compared to other reusable SiHy lens materials. METHODS The release of fluorescently-labelled nitrobenzoxadiazole (NBD)-PEO-PBO was evaluated from serafilcon A over 7 days in a vial. The wettability and coefficient of friction of serafilcon A and three contemporary SiHy contact lens materials (senofilcon A; samfilcon A; comfilcon A) were evaluated using an in vitro blink model over their recommended wearing period; t = 0, 1, 7, 14 days for all lens types and t = 30 days for samfilcon A and comfilcon A (n = 4). Sessile drop contact angles were determined and in vitro non-invasive keratographic break-up time (NIKBUT) measurements were assessed on a blink model via the OCULUS Keratograph 5 M. The coefficient of friction was measured using a nano tribometer. RESULTS The relative fluorescence of NBD-PEO-PBO decreased in serafilcon A by approximately 18 % after 7 days. The amount of NBD-PEO-PBO released on day 7 was 50 % less than the amount released on day 1 (6.5±1.0 vs 3.4±0.5 µg/lens). The reduction in PEO-PBO in the lens also coincided with an increase in contact angles for serafilcon A after 7 days (p < 0.05), although there were no changes in NIKBUT or coefficient of friction (p > 0.05). The other contact lens materials had stable contact angles and NIKBUT over their recommended wearing period (p > 0.05), with the exception of samfilcon A, which had an increase in contact angle after 14 days as compared to t = 0 (p < 0.05). Senofilcon A and samfilcon A also showed an increase in coefficient of friction at 14 and 30 days, respectively, compared to their blister pack values (p < 0.05). CONCLUSION The results indicate that serafilcon A gradually depletes its reserve of PEO-PBO over 1 week, but this decrease did not significantly change the lens performance in vitro during this time frame.
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Affiliation(s)
- Chau-Minh Phan
- Centre for Ocular Research & Education (CORE), School of Optometry and Vision Science, University of Waterloo, 200 University Avenue West, Waterloo, ON N2L 3G1, Canada; Centre for Eye and Vision Research (CEVR), 17W Hong Kong Science Park, Hong Kong, China.
| | - Vivian Wy Chan
- Centre for Ocular Research & Education (CORE), School of Optometry and Vision Science, University of Waterloo, 200 University Avenue West, Waterloo, ON N2L 3G1, Canada
| | - Elizabeth Drolle
- Centre for Ocular Research & Education (CORE), School of Optometry and Vision Science, University of Waterloo, 200 University Avenue West, Waterloo, ON N2L 3G1, Canada
| | - Alex Hui
- Centre for Ocular Research & Education (CORE), School of Optometry and Vision Science, University of Waterloo, 200 University Avenue West, Waterloo, ON N2L 3G1, Canada; School of Optometry and Vision Science, Faculty of Medicine and Health, UNSW Sydney, Australia
| | - William Ngo
- Centre for Ocular Research & Education (CORE), School of Optometry and Vision Science, University of Waterloo, 200 University Avenue West, Waterloo, ON N2L 3G1, Canada; Centre for Eye and Vision Research (CEVR), 17W Hong Kong Science Park, Hong Kong, China
| | - Susmita Bose
- Centre for Ocular Research & Education (CORE), School of Optometry and Vision Science, University of Waterloo, 200 University Avenue West, Waterloo, ON N2L 3G1, Canada
| | - Amanda Shows
- Alcon Research LLC, Fort Worth TX & Johns Creek, GA, USA
| | - Shuang Liang
- Alcon Research LLC, Fort Worth TX & Johns Creek, GA, USA
| | - Vinay Sharma
- Alcon Research LLC, Fort Worth TX & Johns Creek, GA, USA
| | | | - Ying Zheng
- Alcon Research LLC, Fort Worth TX & Johns Creek, GA, USA
| | - Xinfeng Shi
- Alcon Research LLC, Fort Worth TX & Johns Creek, GA, USA
| | - James Wu
- Alcon Research LLC, Fort Worth TX & Johns Creek, GA, USA
| | - Lyndon Jones
- Centre for Ocular Research & Education (CORE), School of Optometry and Vision Science, University of Waterloo, 200 University Avenue West, Waterloo, ON N2L 3G1, Canada; Centre for Eye and Vision Research (CEVR), 17W Hong Kong Science Park, Hong Kong, China
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3
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Wang Y, Borthwell RM, Hori K, Clarkson S, Blumstein G, Park H, Hart CM, Hamad CD, Francis KP, Bernthal NM, Phillips KS. In vitro and in vivo methods to study bacterial colonization of hydrogel dermal fillers. J Biomed Mater Res B Appl Biomater 2022; 110:1932-1941. [PMID: 35352867 PMCID: PMC10371418 DOI: 10.1002/jbm.b.35050] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2021] [Revised: 12/27/2021] [Accepted: 02/09/2022] [Indexed: 11/11/2022]
Abstract
Preclinical in vitro and in vivo methods to study bacterial interactions with dermal fillers and infection pathogenesis are lacking. In this work, first in vitro methods to assess protein biofouling and effective pore size of commercial dermal fillers, including degradable hyaluronic acid (HA)-based fillers and other semi-degradable or permanent fillers (non-HA), were developed. The results were then related to Staphylococcus aureus (S. aureus) adhesion rates in vitro. HA fillers had less protein sorption than non-HA fillers and overall had smaller effective pore sizes. The properties correlated with levels of bacterial adhesion, where the control glass surface had the most rapid increase in bacterial cell adhesion, with a slope of 0.29 cm-2 min-1 , three unique non-HA fillers had intermediate adhesion with slopes of 0.11 and 0.06 cm-2 min-1 , and three unique HA fillers had the least adhesion with slopes of 0.02, 0.02, and 0.01 cm-2 min-1 . S. aureus had greater motility on the HA fillers than on non-HA fillers. Next, a mouse model for dermal filler biofilm and infection was developed. Mice were inoculated with a controlled amount of bioluminescent bacteria (Xen36 S. aureus) and polyacrylamide hydrogels of different stiffness were injected. In vivo bioluminescence was monitored longitudinally for 35 days to ensure that lasting colonization was established. The inoculum was optimized to achieve adequate bioluminescent signal, and bacterial bioburden over time and inter-animal variability in bioburden were determined. These in vitro and in vivo approaches can be used for future studies of antimicrobial interventions for dermal fillers.
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Affiliation(s)
- Yi Wang
- Division of Biology, Chemistry and Materials Science, Center for Devices and Radiological Health, Office of Science and Engineering Laboratories, Office of Medical Products and Tobacco, United States Food and Drug Administration, Silver Spring, Maryland, USA
| | - Rachel M Borthwell
- Department of Orthopaedic Surgery, Orthopaedic Hospital Research Center, David Geffen School of Medicine at University of California Los Angeles, Los Angeles, California, USA
| | - Kellyn Hori
- Department of Orthopaedic Surgery, Orthopaedic Hospital Research Center, David Geffen School of Medicine at University of California Los Angeles, Los Angeles, California, USA
| | - Samuel Clarkson
- Department of Orthopaedic Surgery, Orthopaedic Hospital Research Center, David Geffen School of Medicine at University of California Los Angeles, Los Angeles, California, USA
| | - Gideon Blumstein
- Department of Orthopaedic Surgery, Orthopaedic Hospital Research Center, David Geffen School of Medicine at University of California Los Angeles, Los Angeles, California, USA
| | - Howard Park
- Department of Orthopaedic Surgery, Orthopaedic Hospital Research Center, David Geffen School of Medicine at University of California Los Angeles, Los Angeles, California, USA
| | - Christopher M Hart
- Department of Orthopaedic Surgery, Orthopaedic Hospital Research Center, David Geffen School of Medicine at University of California Los Angeles, Los Angeles, California, USA
| | - Christopher D Hamad
- Department of Orthopaedic Surgery, Orthopaedic Hospital Research Center, David Geffen School of Medicine at University of California Los Angeles, Los Angeles, California, USA
| | - Kevin P Francis
- Department of Orthopaedic Surgery, Orthopaedic Hospital Research Center, David Geffen School of Medicine at University of California Los Angeles, Los Angeles, California, USA
| | - Nicholas M Bernthal
- Department of Orthopaedic Surgery, Orthopaedic Hospital Research Center, David Geffen School of Medicine at University of California Los Angeles, Los Angeles, California, USA
| | - K Scott Phillips
- Division of Biology, Chemistry and Materials Science, Center for Devices and Radiological Health, Office of Science and Engineering Laboratories, Office of Medical Products and Tobacco, United States Food and Drug Administration, Silver Spring, Maryland, USA
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4
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Masoudi S, Willcox M. Development of an enzymatic method for the evaluation of protein deposition on contact lenses. BIOFOULING 2022; 38:84-99. [PMID: 35016572 DOI: 10.1080/08927014.2021.2019225] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/02/2021] [Revised: 12/09/2021] [Accepted: 12/10/2021] [Indexed: 06/14/2023]
Abstract
The aim of this study was to evaluate a new digestion method to quantify protein deposition on contact lenses. Four silicone hydrogel and one hydrogel contact lens material were incubated in lactoferrin, lysozyme, immunoglobulin A, and bovine serum albumin solutions at approximate physiological concentrations and temperature. Immobilized trypsin was used to digest the protein deposits from the contact lens surfaces. The total protein absorbed to lenses was extracted and digested using sequencing grade trypsin. The tryptic peptides were quantified using selected reaction monitoring mass spectrometry. The concentration of surface protein deposits was either lower than or the same as the total protein for all lens types and proteins. Immobilised trypsin can digest protein deposits from the surface of contact lenses. This ability to analyse the amount of protein at a contact lens surface may help in elucidating the effect of surface deposition on clinical outcomes during lens wear.
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Affiliation(s)
- Simin Masoudi
- School of Optometry and Vision Science, University of New South Wales, Sydney, NSW, Australia
| | - Mark Willcox
- School of Optometry and Vision Science, University of New South Wales, Sydney, NSW, Australia
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5
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Lee SW, Phillips KS, Gu H, Kazemzadeh-Narbat M, Ren D. How microbes read the map: Effects of implant topography on bacterial adhesion and biofilm formation. Biomaterials 2020; 268:120595. [PMID: 33360301 DOI: 10.1016/j.biomaterials.2020.120595] [Citation(s) in RCA: 73] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2020] [Revised: 11/24/2020] [Accepted: 12/06/2020] [Indexed: 12/19/2022]
Abstract
Microbes have remarkable capabilities to attach to the surface of implanted medical devices and form biofilms that adversely impact device function and increase the risk of multidrug-resistant infections. The physicochemical properties of biomaterials have long been known to play an important role in biofilm formation. More recently, a series of discoveries in the natural world have stimulated great interest in the use of 3D surface topography to engineer antifouling materials that resist bacterial colonization. There is also increasing evidence that some medical device surface topographies, such as those designed for tissue integration, may unintentionally promote microbial attachment. Despite a number of reviews on surface topography and biofilm control, there is a missing link between how bacteria sense and respond to 3D surface topographies and the rational design of antifouling materials. Motivated by this gap, we present a review of how bacteria interact with surface topographies, and what can be learned from current laboratory studies of microbial adhesion and biofilm formation on specific topographic features and medical devices. We also address specific biocompatibility considerations and discuss how to improve the assessment of the anti-biofilm performance of topographic surfaces. We conclude that 3D surface topography, whether intended or unintended, is an important consideration in the rational design of safe medical devices. Future research on next-generation smart antifouling materials could benefit from a greater focus on translation to real-world applications.
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Affiliation(s)
- Sang Won Lee
- Department of Biomedical and Chemical Engineering, Syracuse University, Syracuse, NY, 13244, United States; Syracuse Biomaterials Institute, Syracuse University, Syracuse, NY, 13244, United States
| | - K Scott Phillips
- United States Food and Drug Administration, Office of Medical Products and Tobacco, Center for Devices and Radiological Health, Office of Science and Engineering Laboratories, Division of Biology, Chemistry, and Materials Science, Silver Spring, MD, 20993, United States.
| | - Huan Gu
- Department of Biomedical and Chemical Engineering, Syracuse University, Syracuse, NY, 13244, United States; Syracuse Biomaterials Institute, Syracuse University, Syracuse, NY, 13244, United States
| | - Mehdi Kazemzadeh-Narbat
- United States Food and Drug Administration, Office of Medical Products and Tobacco, Center for Devices and Radiological Health, Office of Product Evaluation and Quality, Office of Health Technology 6, Silver Spring, MD, 20993, United States; Musculoskeletal Clinical Regulatory Advisers (MCRA), Washington DC, 20001, United States
| | - Dacheng Ren
- Department of Biomedical and Chemical Engineering, Syracuse University, Syracuse, NY, 13244, United States; Syracuse Biomaterials Institute, Syracuse University, Syracuse, NY, 13244, United States; Department of Civil and Environmental Engineering, Syracuse University, Syracuse, NY, 13244, United States; Department of Biology, Syracuse University, Syracuse, NY, 13244, United States.
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6
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Cheung S, Subbaraman LN, Ngo W, Jay GD, Schmidt TA, Jones L. Localization of full-length recombinant human proteoglycan-4 in commercial contact lenses using confocal microscopy. JOURNAL OF BIOMATERIALS SCIENCE-POLYMER EDITION 2019; 31:110-122. [PMID: 31594478 DOI: 10.1080/09205063.2019.1678454] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
The aim of this study was to determine the sorption location of full-length recombinant human proteoglycan 4 (rhPRG4) tagged with fluorescein isothiocyanate (FITC) to four silicone hydrogel contact lenses [balafilcon A (PureVision, Bausch + Lomb), senofilcon A (Acuvue Oasys, Johnson & Johnson), comfilcon A (Biofinity, CooperVision), lotrafilcon B (Air Optix, Alcon)] and one conventional hydrogel lens [etafilcon A (Acuvue 2, Johnson & Johnson)], using confocal laser scanning microscopy (CLSM). Lenses (n = 3 each) were incubated under two conditions: (1) FITC-rhPRG4 solution at 300 μg/mL and (2) phosphate-buffered saline, for 1 h at 37 °C in darkness with gentle shaking. The central 4 mm of each lens was removed and viewed with the Zeiss 510 CLSM using an argon laser at 488 nm (FITC excitation 495 nm, emission 521 nm). Depth scans were taken at 1 μm intervals to a maximum depth of 100 μm. All lens materials demonstrated sorption of rhPRG4. Both senofilcon A and balafilcon A revealed FITC-rhPRG4 penetration into the bulk of the lens, generally favoring the surface. rhPRG4 was observed exclusively on the surface of lotrafilcon B, with no presence within the bulk of the lens. rhPRG4 was evenly distributed throughout the bulk of the lens, as well as on the surface, for comfilcon A and etafilcon A. The sorption profile of FITC-rhPRG4 was successfully visualized using CLSM in various contact lens materials. The polymer composition, surface treatment and pore size of the material can influence the sorption of rhPRG4.
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Affiliation(s)
- Steven Cheung
- Centre for Ocular Research & Education (CORE), School of Optometry and Vision Science, University of Waterloo, Waterloo, Ontario, Canada
| | - Lakshman N Subbaraman
- Centre for Ocular Research & Education (CORE), School of Optometry and Vision Science, University of Waterloo, Waterloo, Ontario, Canada
| | - William Ngo
- Centre for Ocular Research & Education (CORE), School of Optometry and Vision Science, University of Waterloo, Waterloo, Ontario, Canada
| | - Gregory D Jay
- Department of Emergency Medicine, Alpert Medical School & School of Engineering, Brown University, Providence, Rhode Island, USA
| | - Tannin A Schmidt
- Faculty of Kinesiology & Schulich School of Engineering, University of Calgary, Calgary, Alberta, Canada.,Biomedical Engineering Department, University of Connecticut Health Center, Farmington, Connecticut, USA
| | - Lyndon Jones
- Centre for Ocular Research & Education (CORE), School of Optometry and Vision Science, University of Waterloo, Waterloo, Ontario, Canada
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Zheng Y, Xu L, Yang J, Peng X, Wang H, Yu N, Hua Y, Zhao J, He J, Hong T. The effects of fluorescent labels on Aβ42
aggregation detected by fluorescence correlation spectroscopy. Biopolymers 2018; 109:e23237. [DOI: 10.1002/bip.23237] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2018] [Revised: 09/02/2018] [Accepted: 09/13/2018] [Indexed: 01/23/2023]
Affiliation(s)
- Yanpeng Zheng
- School of Sciences; Beijing Jiaotong University; Beijing China
| | - Lingwan Xu
- School of Sciences; Beijing Jiaotong University; Beijing China
| | - Jingfa Yang
- Institute of Chemistry; Chinese Academy of Sciences; Beijing China
| | - Xianglei Peng
- School of Sciences; Beijing Jiaotong University; Beijing China
| | - He Wang
- School of Sciences; Beijing Jiaotong University; Beijing China
| | - Na Yu
- School of Sciences; Beijing Jiaotong University; Beijing China
- Shandong Xinchuang Biological Technology Co., Ltd.; Jinan China
| | - Ying Hua
- School of Sciences; Beijing Jiaotong University; Beijing China
| | - Jiang Zhao
- Institute of Chemistry; Chinese Academy of Sciences; Beijing China
| | - Jinsheng He
- School of Sciences; Beijing Jiaotong University; Beijing China
| | - Tao Hong
- School of Sciences; Beijing Jiaotong University; Beijing China
- Institute for Viral Disease Control and Prevention; Chinese Centre for Disease Control and Prevention; Beijing China
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8
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Guan A, Wang Y, Phillips KS. An extraction free modified o-phthalaldehyde assay for quantifying residual protein and microbial biofilms on surfaces. BIOFOULING 2018; 34:925-934. [PMID: 30362370 DOI: 10.1080/08927014.2018.1521959] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/16/2018] [Revised: 08/27/2018] [Accepted: 09/04/2018] [Indexed: 06/08/2023]
Abstract
Biological contamination of surfaces in industry and healthcare is an important vector of disease transmission. Current assays for detecting surface-adherent contamination require extraction of biological soil. However, physical inaccessibility or poor solubility may limit recovery. Here, how the o-phthalaldehyde (OPA) protein assay can be modified to measure residual protein (modeled with bovine serum albumin) or biofilm on a surface without extraction is described. The assay limit of detection (LOD) for protein was 1.6 µg cm-2. The detection threshold for Staphylococcus epidermis biofilm was 117 µg cm-2. The clinical utility of the method was demonstrated for measurements taken from clinically used endoscopes. Since this method is more sensitive than extraction-based testing, clinical results should not be compared with conventional benchmarks. By enabling direct detection and quantification of soils in complex or hard-to-reach areas, this method has potential to improve the margin of safety in medical and industrial cleaning processes.
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Affiliation(s)
- Allan Guan
- a Division of Biology, Chemistry and Materials Science, Center for Devices and Radiological Health , Office of Science and Engineering Laboratories, Office of Medical Products and Tobacco, United States Food and Drug Administration , Silver Spring , MD , USA
| | - Yi Wang
- a Division of Biology, Chemistry and Materials Science, Center for Devices and Radiological Health , Office of Science and Engineering Laboratories, Office of Medical Products and Tobacco, United States Food and Drug Administration , Silver Spring , MD , USA
| | - K Scott Phillips
- a Division of Biology, Chemistry and Materials Science, Center for Devices and Radiological Health , Office of Science and Engineering Laboratories, Office of Medical Products and Tobacco, United States Food and Drug Administration , Silver Spring , MD , USA
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9
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Wang Y, Guan A, Wickramasekara S, Phillips KS. Analytical Chemistry in the Regulatory Science of Medical Devices. ANNUAL REVIEW OF ANALYTICAL CHEMISTRY (PALO ALTO, CALIF.) 2018; 11:307-327. [PMID: 29579404 DOI: 10.1146/annurev-anchem-061417-125556] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
In the United States, regulatory science is the science of developing new tools, standards, and approaches to assess the safety, efficacy, quality, and performance of all Food and Drug Administration-regulated products. Good regulatory science facilitates consumer access to innovative medical devices that are safe and effective throughout the Total Product Life Cycle (TPLC). Because the need to measure things is fundamental to the regulatory science of medical devices, analytical chemistry plays an important role, contributing to medical device technology in two ways: It can be an integral part of an innovative medical device (e.g., diagnostic devices), and it can be used to support medical device development throughout the TPLC. In this review, we focus on analytical chemistry as a tool for the regulatory science of medical devices. We highlight recent progress in companion diagnostics, medical devices on chips for preclinical testing, mass spectrometry for postmarket monitoring, and detection/characterization of bacterial biofilm to prevent infections.
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Affiliation(s)
- Yi Wang
- Division of Biology, Chemistry, and Materials Science, Office of Science and Engineering Laboratories, Center for Devices and Radiological Health, Office of Medical Products and Tobacco, US Food and Drug Administration, Silver Spring, Maryland 20993, USA;
| | - Allan Guan
- Division of Biology, Chemistry, and Materials Science, Office of Science and Engineering Laboratories, Center for Devices and Radiological Health, Office of Medical Products and Tobacco, US Food and Drug Administration, Silver Spring, Maryland 20993, USA;
| | - Samanthi Wickramasekara
- Division of Biology, Chemistry, and Materials Science, Office of Science and Engineering Laboratories, Center for Devices and Radiological Health, Office of Medical Products and Tobacco, US Food and Drug Administration, Silver Spring, Maryland 20993, USA;
| | - K Scott Phillips
- Division of Biology, Chemistry, and Materials Science, Office of Science and Engineering Laboratories, Center for Devices and Radiological Health, Office of Medical Products and Tobacco, US Food and Drug Administration, Silver Spring, Maryland 20993, USA;
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10
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Chen Y, Hua Y, Zhang W, Tang C, Wang Y, Zhang Y, Qiu F. Amyloid-like staining property of RADA16-I nanofibers and its potential application in detecting and imaging the nanomaterial. Int J Nanomedicine 2018; 13:2477-2489. [PMID: 29719395 PMCID: PMC5922240 DOI: 10.2147/ijn.s159785] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Background Designer self-assembling peptide nanofibers (SAPNFs) as a novel kind of emerging nanomaterial have received more and more attention in the field of nanomedicine in recent years. However, a simple method to monitor and image SAPNFs is still currently absent. Methods RADA16-I, a well-studied ionic complementary peptide was used as a model to check potential amyloid-like staining properties of SAPNFs. Thioflavin-T (ThT) and Congo red (CR) as specific dyes for amyloid-like fibrils were used to stain RADA16-I nanofibers in solution, combined with drugs or cells, or injected in vivo as hydrogels. Fluorescent spectrometry and fluorescent microscopy were used to check ThT-binding property, and polarized light microscopy was used to check CR-staining property. Results ThT binding with the nanofibers showed enhanced and blue-shifted fluorescence, and specific apple-green birefringence could be observed after the nanofibers were stained with CR. Based on these properties we further showed that ThT-binding fluorescence intensity could be used to monitor the forming and changing of nanofibers in solution, while fluorescent microscopy and polarized light microscopy could be used to image the nanofibers as material for drug delivery, 3D cell culture, and tissue regeneration. Conclusion Our results may provide convenient and reliable tools for detecting SAPNFs, which would be helpful for understanding their self-assembling process and exploring their applications.
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Affiliation(s)
- Yongzhu Chen
- Periodical Press of West China Hospital, Sichuan University, Chengdu, China
| | - Yusi Hua
- Department of Anesthesiology, West China Hospital, Sichuan University, Chengdu, China
| | - Wensheng Zhang
- Laboratory of Anaesthesia and Critical Care Medicine, Translational Neuroscience Centre, West China Hospital, Sichuan University, Chengdu, China
| | - Chengkang Tang
- Core Facility of West China Hospital, Sichuan University, Chengdu, China
| | - Yan Wang
- Core Facility of West China Hospital, Sichuan University, Chengdu, China
| | - Yujun Zhang
- Laboratory of Anaesthesia and Critical Care Medicine, Translational Neuroscience Centre, West China Hospital, Sichuan University, Chengdu, China
| | - Feng Qiu
- Laboratory of Anaesthesia and Critical Care Medicine, Translational Neuroscience Centre, West China Hospital, Sichuan University, Chengdu, China
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11
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Walther H, Phan CM, Subbaraman LN, Jones L. Differential Deposition of Fluorescently Tagged Cholesterol on Commercial Contact Lenses Using a Novel In Vitro Eye Model. Transl Vis Sci Technol 2018; 7:18. [PMID: 29644148 PMCID: PMC5892225 DOI: 10.1167/tvst.7.2.18] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2017] [Accepted: 02/17/2018] [Indexed: 11/24/2022] Open
Abstract
Purpose We evaluate the differences in lipid uptake and penetration in daily disposable (DD) contact lenses (CL) using a conventional “in-vial” method compared to a novel in vitro eye model. Methods The penetration of fluorescently labelled 22-(N-(7-Nitrobenz-2-Oxa-1,3-Diazol-4-yl)Amino)-23,24-Bisnor-5-Cholen-3beta-Ol (NBD)–cholesterol on three silicone hydrogel (SH) and four conventional hydrogel (CH) DD CLs were investigated. CLs were incubated for 4 and 12 hours in a vial, containing 3.5 mL artificial tear solution (ATS), or were mounted on an in vitro eye-blink platform designed to simulate physiologic tear flow (2 mL/24 hours), tear volume and “simulated” blinking. Subsequently, CLs were analyzed using laser scanning confocal microscopy and ImageJ. Results Penetration depth and fluorescence intensities of NBD-cholesterol varied between the incubation methods as well as lens materials. Using the traditional vial incubation method, NBD-cholesterol uptake occurred equally on both sides of all lens materials. However, using our eye-blink model, cholesterol penetration was observed primarily on the anterior surface of the CLs. In general, SH lenses showed higher intensities of NBD-cholesterol than CH materials. Conclusions The traditional “in-vial” incubation method exposes the CLs to an excessively high amount of ATS, which results in an overestimation for cholesterol deposition. Our model, which incorporates important ocular factors, such as intermittent air exposure, small tear volume, and physiological tear flow between blinks, provides a more natural environment for in vitro lens incubation. Translational Relevance In vitro measurements of CLs are a common approach to predict their interactions and performance on the eye. Traditional methods, however, are rudimentary. Therefore, this study presents a novel in vitro model to evaluate CLs, which consequently will enhance elucidations of the interactions between CLs and the eye.
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Affiliation(s)
- Hendrik Walther
- Centre for Ocular Research & Education (CORE) - formerly Centre for Contact Lens Research (CCLR), School of Optometry and Vision Science, Waterloo, Ontario, Canada
| | - Chau-Minh Phan
- Centre for Ocular Research & Education (CORE) - formerly Centre for Contact Lens Research (CCLR), School of Optometry and Vision Science, Waterloo, Ontario, Canada
| | - Lakshman N Subbaraman
- Centre for Ocular Research & Education (CORE) - formerly Centre for Contact Lens Research (CCLR), School of Optometry and Vision Science, Waterloo, Ontario, Canada
| | - Lyndon Jones
- Centre for Ocular Research & Education (CORE) - formerly Centre for Contact Lens Research (CCLR), School of Optometry and Vision Science, Waterloo, Ontario, Canada
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A Review of Techniques to Measure Protein Sorption to Soft Contact Lenses. Eye Contact Lens 2017; 43:276-286. [PMID: 28198731 DOI: 10.1097/icl.0000000000000366] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE To compare and critically evaluate a variety of techniques to measure the quantity and biological activity of protein sorption to contact lenses over short time periods. METHODS A literature review was undertaken investigating the major techniques to measure protein sorption to soft contact lens materials, with specific reference to measuring protein directly on lenses using in situ, ex situ, protein structural, and biological activity techniques. RESULTS The use of in situ techniques to measure protein quantity provides excellent sensitivity, but many are not directly applicable to contact lenses. Many ex situ techniques struggle to measure all sorbed proteins, and these measurements can have significant signal interference from the lens materials themselves. Techniques measuring the secondary and tertiary structures of sorbed proteins have exhibited only limited success. CONCLUSIONS There are a wide variety of techniques to measure both the amount of protein and the biological activity of protein sorbed to soft contact lens materials. To measure the mass of protein sorbed to soft contact lenses (not just thin films) over short time periods, the method of choice should be I radiolabeling. This technique is sensitive enough to measure small amounts of deposited protein, provided steps are taken to limit and measure any interaction of the iodine tracer with the materials. To measure the protein activity over short time periods, the method of choice should be to measure the biological function of sorbed proteins. This may require new methods or adaptations of existing ones.
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Winzen S, Koynov K, Landfester K, Mohr K. Fluorescence labels may significantly affect the protein adsorption on hydrophilic nanomaterials. Colloids Surf B Biointerfaces 2016; 147:124-128. [PMID: 27497932 DOI: 10.1016/j.colsurfb.2016.07.057] [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: 05/09/2016] [Revised: 07/27/2016] [Accepted: 07/28/2016] [Indexed: 01/24/2023]
Abstract
Fluorescently labelled proteins are often used to study processes in vitro, e.g. the binding of proteins to cell surfaces or the adsorption of plasma proteins on drug nanocarriers. However, the fact that the fluorescent labelling may affect the protein properties is frequently neglected. On the example of a simple model system, we reiterate the importance of this issue by showing that even a single label may perturb interactions between hydrophilic starch-based nanocapsules and serum albumin and thus prevent binding.
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Affiliation(s)
- Svenja Winzen
- Max Planck Institute for Polymer Research, Ackermannweg 10, D-55128 Mainz, Germany.
| | - Kaloian Koynov
- Max Planck Institute for Polymer Research, Ackermannweg 10, D-55128 Mainz, Germany.
| | - Katharina Landfester
- Max Planck Institute for Polymer Research, Ackermannweg 10, D-55128 Mainz, Germany.
| | - Kristin Mohr
- Max Planck Institute for Polymer Research, Ackermannweg 10, D-55128 Mainz, Germany.
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McCracken JM, Badea A, Kandel ME, Gladman AS, Wetzel DJ, Popescu G, Lewis JA, Nuzzo RG. Programming Mechanical and Physicochemical Properties of 3D Hydrogel Cellular Microcultures via Direct Ink Writing. Adv Healthc Mater 2016; 5:1025-39. [PMID: 26924676 DOI: 10.1002/adhm.201500888] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2015] [Revised: 01/28/2016] [Indexed: 11/12/2022]
Abstract
3D hydrogel scaffolds are widely used in cellular microcultures and tissue engineering. Using direct ink writing, microperiodic poly(2-hydroxyethyl-methacrylate) (pHEMA) scaffolds are created that are then printed, cured, and modified by absorbing 30 kDa protein poly-l-lysine (PLL) to render them biocompliant in model NIH/3T3 fibroblast and MC3T3-E1 preosteoblast cell cultures. Spatial light interference microscopy (SLIM) live cell imaging studies are carried out to quantify cellular motilities for each cell type, substrate, and surface treatment of interest. 3D scaffold mechanics is investigated using atomic force microscopy (AFM), while their absorption kinetics are determined by confocal fluorescence microscopy (CFM) for a series of hydrated hydrogel films prepared from prepolymers with different homopolymer-to-monomer (Mr ) ratios. The observations reveal that the inks with higher Mr values yield relatively more open-mesh gels due to a lower degree of entanglement. The biocompatibility of printed hydrogel scaffolds can be controlled by both PLL content and hydrogel mesh properties.
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Affiliation(s)
- Joselle M. McCracken
- School of Chemical Sciences; University of Illinois Urbana-Champaign; Urbana IL 61801 USA
| | - Adina Badea
- School of Chemical Sciences; University of Illinois Urbana-Champaign; Urbana IL 61801 USA
| | - Mikhail E. Kandel
- Department of Electrical and Computer Engineering; University of Illinois Urbana-Champaign; Urbana IL 61801 USA
| | - A. Sydney Gladman
- Wyss Institute; School of Engineering and Applied Sciences; Harvard University; Cambridge MA 02138 USA
| | - David J. Wetzel
- School of Chemical Sciences; University of Illinois Urbana-Champaign; Urbana IL 61801 USA
| | - Gabriel Popescu
- Department of Electrical and Computer Engineering; University of Illinois Urbana-Champaign; Urbana IL 61801 USA
| | - Jennifer A. Lewis
- Wyss Institute; School of Engineering and Applied Sciences; Harvard University; Cambridge MA 02138 USA
| | - Ralph G. Nuzzo
- School of Chemical Sciences; University of Illinois Urbana-Champaign; Urbana IL 61801 USA
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Guan A, Wang Y, Phillips KS, Li Z. A contact-lens-on-a-chip companion diagnostic tool for personalized medicine. LAB ON A CHIP 2016; 16:1152-1156. [PMID: 26923038 DOI: 10.1039/c6lc00034g] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
We present a novel, microfluidic platform that integrates human tears (1 μL) with commercial contact lens materials to provide personalized assessment of lens care solution performance. This device enabled the detection of significant differences in cleaning and disinfection outcomes between subjects and between biofilms vs. planktonic bacteria.
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Affiliation(s)
- Allan Guan
- Department of Biomedical Engineering, The George Washington University, 800 22nd Street NW, Washington, DC 20052, USA.
| | - Yi Wang
- Division of Biology, Chemistry and Materials Science, Office of Science and Engineering Laboratories, Center for Devices and Radiological Health, U.S. Food and Drug Administration, 10903 New Hampshire Avenue, Silver Spring, MD 20993, USA.
| | - K Scott Phillips
- Division of Biology, Chemistry and Materials Science, Office of Science and Engineering Laboratories, Center for Devices and Radiological Health, U.S. Food and Drug Administration, 10903 New Hampshire Avenue, Silver Spring, MD 20993, USA.
| | - Zhenyu Li
- Department of Biomedical Engineering, The George Washington University, 800 22nd Street NW, Washington, DC 20052, USA.
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Romanowska J, Kokh DB, Wade RC. When the Label Matters: Adsorption of Labeled and Unlabeled Proteins on Charged Surfaces. NANO LETTERS 2015; 15:7508-7513. [PMID: 26491986 DOI: 10.1021/acs.nanolett.5b03168] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Fluorescent labels are often attached to proteins to monitor binding and adsorption processes. Docking simulations for native hen egg white lysozyme (HEWL) and HEWL labeled with fluorescein isothiocyanate show that these adsorb differently on charged surfaces. Attachment of even a small label can significantly change the interaction properties of a protein. Thus, the results of experiments with fluorescently labeled proteins should be interpreted by modeling the structures and computing the interaction properties of both labeled and unlabeled species.
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Affiliation(s)
- Julia Romanowska
- Molecular and Cellular Modeling Group, Heidelberg Institute for Theoretical Studies , 69117 Heidelberg, Germany
| | - Daria B Kokh
- Molecular and Cellular Modeling Group, Heidelberg Institute for Theoretical Studies , 69117 Heidelberg, Germany
| | - Rebecca C Wade
- Molecular and Cellular Modeling Group, Heidelberg Institute for Theoretical Studies , 69117 Heidelberg, Germany
- Zentrum für Molekulare Biologie der Universität Heidelberg, DKFZ-ZMBH Alliance, Heidelberg University , 69117 Heidelberg, Germany
- Interdisciplinary Center for Scientific Computing (IWR), Heidelberg University , 69117 Heidelberg, Germany
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Frey J, Guan A, Li Z, Turtil S, Phillips KS. Hemoglobin assay for validation and quality control of medical device reprocessing. Anal Bioanal Chem 2015; 407:6885-9. [DOI: 10.1007/s00216-015-8856-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2015] [Revised: 06/10/2015] [Accepted: 06/15/2015] [Indexed: 11/24/2022]
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Jalani G, Naccache R, Rosenzweig DH, Lerouge S, Haglund L, Vetrone F, Cerruti M. Real-time, non-invasive monitoring of hydrogel degradation using LiYF4:Yb(3+)/Tm(3+) NIR-to-NIR upconverting nanoparticles. NANOSCALE 2015; 7:11255-11262. [PMID: 26067274 DOI: 10.1039/c5nr02482j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
To design a biodegradable hydrogel as cell support, one should know its in vivo degradation rate. A technique commonly used to track gel degradation is fluorescence spectroscopy. However, the fluorescence from conventional fluorophores quickly decays, and the fluorophores are often moderately cytotoxic. Most importantly, they require ultraviolet or visible (UV-Vis) light as the excitation source, which cannot penetrate deeply through biological tissues. Lanthanide-doped upconverting nanoparticles (UCNPs) are exciting alternatives to conventional fluorophores because they can convert near-infrared (NIR) to UV-Vis-NIR light via a sequential multiphoton absorption process referred to as upconversion. NIR light can penetrate up to few cm inside tissues, thus making these UCNPs much better probes than conventional fluorophores for in vivo monitoring. Also, UCNPs have narrow emission bands, high photoluminescence (PL) signal-to-noise ratio, low cytotoxicity and good physical and chemical stability. Here, we show a nanocomposite system consisting of a biodegradable, in situ thermogelling injectable hydrogel made of chitosan and hyaluronic acid encapsulating silica-coated LiYF4:Yb(3+)/Tm(3+) UCNPs. We use these UCNPs as photoluminescent tags to monitor the gel degradation inside live, cultured intervertebral discs (IVDs) over a period of 3 weeks. PL spectroscopy and NIR imaging show that NIR-to-NIR upconversion of LiYF4:Yb(3+)/Tm(3+)@SiO2 UCNPs allows for tracking of the gel degradation in living tissues. Both in vitro and ex vivo release of UCNPs follow a similar trend during the first 5 days; after this time, ex vivo release becomes faster than in vitro, indicating a faster gel degradation ex vivo. Also, the amount of released UCNPs in vitro increases continuously up to 3 weeks, while it plateaus after 15 days inside the IVDs showing a homogenous distribution of UCNPs throughout the IVD tissue. This non-invasive optical method for real time, live tissue imaging holds great potential for tissue analysis, biomapping and bioimaging applications.
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Affiliation(s)
- Ghulam Jalani
- Department of Mining and Materials Engineering, McGill University, Montreal, QC H3A 0C5, Canada.
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Guan A, Li Z, Phillips KS. The effects of non-ionic polymeric surfactants on the cleaning of biofouled hydrogel materials. BIOFOULING 2015; 31:689-697. [PMID: 26469384 DOI: 10.1080/08927014.2015.1094690] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Block co-polymer surfactants have been used for cleaning hydrogel medical devices that contact the body (e.g., contact lenses) because of their biocompatibility. This work examined the relationship between concentration and detergency of two non-ionic polymeric surfactants (Pluronic F127 and Triton X-100) for cleaning protein soil, with anionic surfactants (sodium dodecyl sulfate and sodium laureth sulfate) as positive controls. Surface plasmon resonance was used to quantify removal of simulated tear soil from self-assembled monolayer surfaces, and a microplate format was used to study the removal of fluorescently labeled soil proteins from contact lenses. While detergency increased as a function of concentration for anionic surfactants, it decreased with concentration for the two polymeric surfactants. The fact that the protein detergency of some non-ionic polymeric surfactants did not increase with concentration above the critical micelle concentration could have implications for optimizing the tradeoff between detergency and biocompatibility.
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Affiliation(s)
- Allan Guan
- a Department of Biomedical Engineering , The George Washington University , Washington , DC , USA
| | - Zhenyu Li
- a Department of Biomedical Engineering , The George Washington University , Washington , DC , USA
| | - K Scott Phillips
- b Division of Biology, Chemistry and Materials Science , United States Food and Drug Administration, Office of Medical Products and Tobacco, Center for Devices and Radiological Health, Office of Science and Engineering Laboratories , Silver Spring , MD , USA
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