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Koo HB, Heo E, Cho I, Kim SH, Kang J, Chang JB. Human hand-inspired all-hydrogel gripper with a high load capacity formed by the split-brushing adhesion of diverse hydrogels. MATERIALS HORIZONS 2023; 10:2075-2085. [PMID: 36920793 DOI: 10.1039/d2mh01309f] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Human hands are highly versatile. Even though they are primarily made of materials with high water content, they exhibit a high load capacity. However, existing hydrogel grippers do not possess a high load capacity due to their innate softness and mechanical strength. This work demonstrates a human hand-inspired all-hydrogel gripper that can bear more than 47.6 times its own weight. This gripper is made of two hydrogels: poly(methacrylamide-co-methacrylic acid) (P(MAAm-co-MAAc)) and poly(N-isopropylacrylamide) (PNIPAM). P(MAAm-co-MAAc) is extremely stiff but becomes soft above its transition temperature. By taking advantage of the difference in the kinetics of the stiff-soft transition of P(MAAm-co-MAAc) hydrogels and the swelling-shrinking transition of PNIPAM hydrogels, this gripper can be switched between its stiff-bent and stiff-stretched states by simply changing the temperature. The assembly of these two hydrogels into a gripper necessitated the development of a new hydrogel adhesion method, as existing topological adhesion methods are not applicable to such stiff hydrogels. A new hydrogel adhesion method, termed split-brushing adhesion, has been demonstrated to satisfy this need. When applied to P(MAAm-co-MAAc) hydrogels, this method achieves an adhesion energy of 1221.6 J m-2, which is 67.5 times higher than that achieved with other topological adhesion methods.
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Affiliation(s)
- Hye Been Koo
- Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Republic of Korea.
| | - Eunseok Heo
- Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Republic of Korea.
| | - In Cho
- Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Republic of Korea.
| | - Sun Hong Kim
- Department of Electronic Engineering, Hanyang University, Seoul, 04763, Republic of Korea
| | - Jiheong Kang
- Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Republic of Korea.
| | - Jae-Byum Chang
- Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Republic of Korea.
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Chawla D, Eriten M, Henak CR. Effect of osmolarity and displacement rate on cartilage microfracture clusters failure into two regimes. J Mech Behav Biomed Mater 2022; 136:105467. [PMID: 36198233 DOI: 10.1016/j.jmbbm.2022.105467] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2022] [Revised: 08/16/2022] [Accepted: 09/12/2022] [Indexed: 11/22/2022]
Abstract
Articular cartilage is a poroviscoelastic (PVE) material with remarkable resistance to fracture and fatigue failure. Cartilage failure mechanisms and material properties that govern failure are incompletely understood. Because cartilage is partially comprised of negatively charged glycosaminoglycans, altering solvent osmolarity can influence PVE relaxations. Therefore, this study aims to use osmolarity as a tool to provide additional data to interpret the role of PVE relaxations and identify cartilage failure regimes. Cartilage fracture was induced using a 100 μm radius spheroconical indenter at controlled displacement rates under three different osmolarity solvents. Secondarily, contact pressure (CP) and strain energy density (SED) were estimated to cluster data into two failure regimes with an expectation maximization algorithm. Critical displacement, critical load, critical time, and critical work to fracture increased with increasing osmolarity at a slow displacement rate whereas no significant effect was observed at a fast displacement rate. Clustering provided two distinct failure regimes, with regime (I) at lower normalized thickness (contact radius divided by sample thickness), and regime (II) at higher normalized thickness. Varied CP and SED in regime (I) suggest that failure in the regime is strain-governed. Constant CP and SED in regime (II) suggests that failure in the regime is dominantly governed by stress. These regimes can be interpreted as ductile versus brittle, or using a pressurized fragmentation interpretation. These findings demonstrated fundamental failure properties and postulate failure regimes for articular cartilage.
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Affiliation(s)
- Dipul Chawla
- Department of Mechanical Engineering, University of Wisconsin-Madison, 1513 University Ave., Madison, WI, 53706, USA
| | - Melih Eriten
- Department of Mechanical Engineering, University of Wisconsin-Madison, 1513 University Ave., Madison, WI, 53706, USA
| | - Corinne R Henak
- Department of Mechanical Engineering, University of Wisconsin-Madison, 1513 University Ave., Madison, WI, 53706, USA; Department of Biomedical Engineering, University of Wisconsin-Madison, 1550 University Ave., Madison, WI, 53706, USA; Department of Orthopedics and Rehabilitation, University of Wisconsin-Madison, 1111 Highland Ave., Madison, WI, 53705, USA.
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Sayed M, Nikaido T, Abdou A, Burrow MF, Tagami J. Potential use of silver diammine fluoride in detection of carious dentin. Dent Mater J 2021; 40:820-826. [PMID: 33775985 DOI: 10.4012/dmj.2020-308] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
This study aimed to examine whether discoloration of carious dentin after silver-diammine-fluoride (SDF) application might be used as a mean to detect demineralized-dentin. Fourty specimens were obtained from 20 human permanent teeth. Teeth were sectioned through the center of carious lesions to create 2-halves in which each half was assigned to a treatment group. Specimens were divided into two groups (n=20) (each half was assigned to one group) according to solution, namely Caries Check (CC), or SDF. SDF group was subdivided into 2 groups: light-cured and 2-day storage groups. The specimens were tested using light-microscope, microhardness test and SEM/EDS analysis. Repeated-measures ANOVA was used for statistical analysis. The light-microscope showed superficial discoloration in the CC-group while SDF (2-day storage) group showed deeper discoloration for the lesion area. SDF showed significant increase in the hardness compared with the CC-group. SDF showed potentiality to be used as an assisting-tool for caries detection.
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Affiliation(s)
- Mahmoud Sayed
- Department of Cariology and Operative Dentistry, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University (TMDU)
| | - Toru Nikaido
- Department of Cariology and Operative Dentistry, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University (TMDU).,Department of Operative Dentistry, Division of Oral Functional Science and Rehabilitation, School of Dentistry, Asahi University
| | - Ahmed Abdou
- Department of Cariology and Operative Dentistry, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University (TMDU).,Biomaterials Department, Faculty of Oral and Dental Medicine, Modern University for Technology and Information
| | | | - Junji Tagami
- Department of Cariology and Operative Dentistry, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University (TMDU)
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Tomasetti L, Breunig M. Preventing Obstructions of Nanosized Drug Delivery Systems by the Extracellular Matrix. Adv Healthc Mater 2018; 7. [PMID: 29121453 DOI: 10.1002/adhm.201700739] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2017] [Revised: 08/25/2017] [Indexed: 12/13/2022]
Abstract
Although nanosized drug delivery systems are promising tools for the treatment of severe diseases, the extracellular matrix (ECM) constitutes a major obstacle that endangers therapeutic success. Mobility of diffusing species is restricted not only by small pore size (down to as low as 3 nm) but also by electrostatic interactions with the network. This article evaluates commonly used in vitro models of ECM, analytical methods, and particle types with respect to their similarity to native conditions in the target tissue. In this cross-study evaluation, results from a wide variety of mobility studies are analyzed to discern general principles of particle-ECM interactions. For instance, cross-linked networks and a negative network charge are essential to reliably recapitulate key features of the native ECM. Commonly used ECM mimics comprised of one or two components can lead to mobility calculations which have low fidelity to in vivo results. In addition, analytical methods must be tailored to the properties of both the matrix and the diffusing species to deliver accurate results. Finally, nanoparticles must be sufficiently small to penetrate the matrix pores (ideally Rd/p < 0.5; d = particle diameter, p = pore size) and carry a neutral surface charge to avoid obstructions. Larger (Rd/p >> 1) or positively charged particles are trapped.
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Affiliation(s)
- Luise Tomasetti
- Department of Pharmaceutical Technology; University of Regensburg; Universitaetsstrasse 31 93040 Regensburg Germany
| | - Miriam Breunig
- Department of Pharmaceutical Technology; University of Regensburg; Universitaetsstrasse 31 93040 Regensburg Germany
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Silva JV, Lortal S, Floury J. Diffusion behavior of dextrans in dairy systems of different microstructures. Food Res Int 2015. [DOI: 10.1016/j.foodres.2015.02.006] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Baikeev RF, Gubanov RA, Sadikov KK, Safina SZ, Muhamadiev FF, Sibgatullin TA. Dynamic properties of water in breast pathology depend on the histological compounds: distinguishing tissue malignancy by water diffusion coefficients. BMC Res Notes 2014; 7:887. [PMID: 25487139 PMCID: PMC4295355 DOI: 10.1186/1756-0500-7-887] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2013] [Accepted: 11/18/2014] [Indexed: 11/11/2022] Open
Abstract
Background The parameters that characterize the intricate water diffusion in tumors may also reveal their distinct pathology. Specifically, characterization of breast cancer could be aided by diffusion magnetic resonance. The present in vitro study aimed to discover connections between the NMR biexponential diffusion parameters [fast diffusion phase (DFDP ), slow diffusion phase (DSDP ), and spin population of fast diffusion phase (P1)] and the histological constituents of nonmalignant (control) and malignant human breast tissue. It also investigates whether the diffusion coefficients indicate tissue status. Methods Post-surgical specimens of control (mastopathy and peritumoral tissues) and malignant human breast tissue were placed in an NMR spectrometer and diffusion sequences were applied. The resulting decay curves were analyzed by a biexponential model, and slow and fast diffusion parameters as well as percentage signal were identified. The same samples were also histologically examined and their percentage composition of several tissue constituents were measured: parenchyma (P), stroma (St), adipose tissue (AT), vessels (V) , pericellular edema (PCE), and perivascular edema (PVE). Correlations between the biexponential model parameters and tissue types were evaluated for different specimens. The effects of tissue composition on the biexponential model parameters, and the effects of histological and model parameters on cancer probability, were determined by non-linear regression. Results Meaningful relationships were found among the in vitro data. The dynamic parameters of water in breast tissue are stipulated by the histological constituents of the tissues (P, St, AT, PCE, and V). High coefficients of determination (R2) were obtained in the non-linear regression analysis: DFDP (R2 = 0.92), DSDP (R2 = 0.81), and P1(R2 = 0.93). In the cancer probability analysis, the informative value (R2) of the obtained equations of cancer probability in distinguishing tissue malignancy depended on the parameters input to the model. In order of increasing value, these equations were: cancer probability (P, St, AT, PCE, V) (R2 = 0.66), cancer probability (DFDP, DSDP)(R2 = 0.69), cancer probability (DFDP, DSDP, P1) (R2 = 0.85). Conclusion Histological tissue components are related to the diffusion biexponential model parameters. From these parameters, the relative probability of cancer in a given specimen can be determined with some certainty.
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Affiliation(s)
- Rustem F Baikeev
- Department of Biochemistry, Kazan State Medical University, Butlerova St,, 49, Kazan, Tatarstan, Russia.
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Schiller J, Huster D. New methods to study the composition and structure of the extracellular matrix in natural and bioengineered tissues. BIOMATTER 2014; 2:115-31. [PMID: 23507863 PMCID: PMC3549865 DOI: 10.4161/biom.20866] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
The extracellular matrix (ECM) comprises a gel of numerous biopolymers that occurs in a multitude of biological tissues. The ECM provides the basic support and mechanical strength of skeletal tissue and is responsible for shape retention. At the same time, the ECM is responsible for the viscoelastic properties and the elasticity of soft tissues. As expected, there are several important diseases that affect and degenerate the ECM with severe consequences for its properties. Bioengineering is a promising approach to support the regenerative capacity of the body. Unfortunately, the biomechanical properties of bioengineered ECM often only poorly meet the standards of their native counterparts. Many bioengineered tissues are characterized by an increased glycosaminoglycan (GAG) but decreased collagen content. This leads to an enhanced water content that strongly alters the viscoelastic and thus the biomechanical properties. Therefore, compositional analysis is important to estimate the tissue quality. We will show that nuclear magnetic resonance (NMR) spectroscopy and soft-ionization mass spectrometry (MS) represent useful techniques for ECM research both in natural and bioengineered tissues. Both methods are strongly complimentary: while MS techniques such as matrix-assisted laser desorption and ionization (MALDI) are excellent and very sensitive analytical tools to determine the collagen and the GAG contents of tissues, NMR spectroscopy provides insight into the molecular architecture of the ECM, its dynamics and other important parameters such as the water content of the tissue as well as the diffusion of molecules within the ECM.
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Affiliation(s)
- Jürgen Schiller
- University of Leipzig, Medical Faculty, Institute of Medical Physics and Biophysics, Leipzig, Germany.
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Bougault C, Cueru L, Bariller J, Malbouyres M, Paumier A, Aszodi A, Berthier Y, Mallein-Gerin F, Trunfio-Sfarghiu AM. Alteration of cartilage mechanical properties in absence of β1 integrins revealed by rheometry and FRAP analyses. J Biomech 2013; 46:1633-40. [DOI: 10.1016/j.jbiomech.2013.04.013] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2012] [Revised: 04/08/2013] [Accepted: 04/14/2013] [Indexed: 10/26/2022]
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Occhipinti P, Griffiths PC. Quantifying diffusion in mucosal systems by pulsed-gradient spin-echo NMR. Adv Drug Deliv Rev 2008; 60:1570-82. [PMID: 18940211 DOI: 10.1016/j.addr.2008.08.006] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2008] [Accepted: 08/28/2008] [Indexed: 01/22/2023]
Abstract
Mucus, a thick and slimy secretion produced by submucosal cells, covers many epithelial surfaces in mammalian organs and prevents foreign particles that enter the body from accessing cells. However, the mucus layer also represents a potential barrier to the efficient delivery of nano-sized drug delivery systems (polyplexes, lipoplexes, particles) to the underlying mucosal epithelium. Many studies have considered the ability of nano-sized particles and polymers to diffuse within the mucosal network using a range of different techniques, including multiple-particle tracking (MPT), diffusion chamber studies and fluorescence recovery after photobleaching (FRAP). This review highlights the current understanding of the interaction of the diffusion of nano-sized structures within mucosal networks. Moreover, this article presents an introduction to pulsed-gradient spin-echo NMR (PGSE-NMR), a potential new tool to investigate the mobility of molecular species through mucosal networks and related biological gels.
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Affiliation(s)
- Paola Occhipinti
- School of Chemistry, Cardiff University, Main Building, Park Place, Cardiff CF10 3AT, UK.
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Hosoya Y, Taguchi T, Arita S, Tay FR. Clinical evaluation of polypropylene glycol-based caries detecting dyes for primary and permanent carious dentin. J Dent 2008; 36:1041-7. [PMID: 18938022 DOI: 10.1016/j.jdent.2008.08.010] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2008] [Revised: 08/29/2008] [Accepted: 08/29/2008] [Indexed: 10/21/2022] Open
Abstract
OBJECTIVE The aim of this study was to compare the clinical efficacy of new caries detecting dye Caries Check Blue (CCB) with Caries Check (CC) and Caries Detector (CD) using a laser fluorescence device (DIAGNOdent). METHOD Primary and permanent teeth with dentin caries were stained with polypropylene glycol (MW=300) based new caries detecting dyes CCB, CC, or propylene glycol (MW=76) based CD. In the CCB and CC groups, stained dentin was completely removed. In the CD groups, pink-stained dentin was retained according to the manufacturers' instructions. Cavities before and after caries removal were measured with the DIAGNOdent. Data were analyzed using ANOVA and Fisher's PLSD multiple comparison test at alpha=0.05. Regression analyses were performed between DIAGNOdent readings and scores obtained from the clinical parameters. RESULTS The DIAGNOdent readings after caries removal were: primary-CCB (13.2+/-10.4), primary-CC (14.3+/-16.7), primary-CD (9.0+/-5.2), permanent-CCB (22.7+/-13.4), permanent-CC (10.6+/-6.8) and permanent-CD (9.7+/-9.0). Significant differences were identified between the permanent-CCB and all other groups. Correlation coefficients between DIAGNOdent readings and clinical parameters were low. CONCLUSIONS When dentin stained with Caries Check Blue or Caries Check was completely removed, the DIAGNOdent readings were higher than those recorded when palely-stained pink dentin was retained with the Caries Detector, with significant difference observed for the permanent-CCB group. Caries Check Blue may be used clinically to avoid excessive removal of caries-affected or sound dentin in permanent teeth but not in primary teeth.
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Affiliation(s)
- Y Hosoya
- Nagasaki University Graduate School of Biomedical Sciences, Medical and Dental Sciences, Unit of Translational Medicine, Department of Pediatric Dentistry, 1-7-1, Sakamoto, Nagasaki, 852-8588, Japan.
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Le Feunteun S, Mariette F. Effects of Acidification with and without Rennet on a Concentrated Casein System: A Kinetic NMR Probe Diffusion Study. Macromolecules 2008. [DOI: 10.1021/ma702248z] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Steven Le Feunteun
- Cemagref, Food Process Engineering Research Unit, CS 64426, 17 avenue de Cucillé, 35044 Rennes Cedex, France
| | - François Mariette
- Cemagref, Food Process Engineering Research Unit, CS 64426, 17 avenue de Cucillé, 35044 Rennes Cedex, France
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Le Feunteun S, Mariette F. Impact of casein gel microstructure on self-diffusion coefficient of molecular probes measured by 1H PFG-NMR. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2007; 55:10764-10772. [PMID: 18047279 DOI: 10.1021/jf071982v] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
The translational dynamics of poly(ethylene glycol) (PEG) polymers with molecular weights (Mw) varying from 6x10(2) to 5x10(5) were investigated by pulsed field gradient NMR in casein suspensions and in gels induced by acidification, enzyme action, and a combination of both. For molecules with Mw<or=1020, the diffusion was only dependent on the casein concentration whatever the molecular weight of the probe or the sample studied. However, for PEG with Mw>or=8000, there was strong dependence of diffusion on PEG size and on the casein network structure as revealed by scanning electron microscopy images. The diffusion coefficients of the two largest PEGs were increased after coagulation by amounts that depended on the internal structure of the gel. In addition, the 527,000 g/mol PEG was found to deviate from Gaussian diffusion behavior to greater or lesser extents according to the casein concentration and the sample microstructure. The results are discussed in terms of network rearrangements.
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Cosgrove T, Rodin V, Murray M, Buscall R. Self-diffusion in solutions of carboxylated acrylic polymers as studied by Pulsed Field Gradient NMR. 2. Diffusion of macromolecules. JOURNAL OF POLYMER RESEARCH 2007. [DOI: 10.1007/s10965-006-9088-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Hosoya Y, Taguchi T, Tay FR. Evaluation of a new caries detecting dye for primary and permanent carious dentin. J Dent 2007; 35:137-43. [PMID: 16945461 DOI: 10.1016/j.jdent.2006.06.004] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2006] [Revised: 06/04/2006] [Accepted: 06/19/2006] [Indexed: 10/24/2022] Open
Abstract
OBJECTIVE This study evaluated the clinical efficacy of a new caries detecting dye using a laser fluorescence device (DIAGNOdent). METHOD Primary and permanent teeth with dentin caries were stained with Caries Check (CC), containing 1% acid red in polypropylene glycol (MW=300) or Caries Detector (CD), containing 1% acid red in propylene glycol (MW=76). Primary-CC, primary-CD, permanent-CC and permanent-CD groups were prepared. In the CC groups, stained dentin was completely removed. In the CD groups, pink-stained dentin was retained according to the manufacturers' instructions. Cavities before and after caries removal were measured with the DIAGNOdent. Data were analyzed using ANOVA and Fisher's PLSD multiple comparison test at alpha=0.05. Regression analyses were performed between DIAGNOdent readings and scores obtained from the clinical parameters. RESULTS For all groups, there were no significant differences in the DIAGNOdent readings before treatment. The DIAGNOdent readings after caries removal were: primary-CC (16.0+/-17.6), primary-CD (9.6+/-5.2), permanent-CC (11.0+/-7.0) and permanent-CD (7.1+/-3.8). Significant differences were identified between the permanent-CC and primary-CD, and permanent-CC and permanent-CD subgroups but not for the primary subgroups. Correlation coefficients between DIAGNOdent readings and clinical parameters were low. CONCLUSIONS When dentin stained with Caries Check was completely removed, the DIAGNOdent readings were higher than those recorded when palely-stained pink dentin was retained with the Caries Detector, with significant difference observed for the permanent teeth. Caries Check may be used clinically to avoid excessive removal of caries-affected or sound dentin in permanent teeth but not in primary teeth.
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Affiliation(s)
- Y Hosoya
- Nagasaki University Graduate School of Biomedical Sciences, Course of Medical and Dental Sciences, Department of Developmental and Reconstractive Medicine, Division of Pediatric Dentistry, 1-7-1, Sakamoto, Nagasaki 852-8588, Japan.
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15
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Cosgrove T, Rodin V, Murray M, Buscall R. Self-diffusion in Solutions of Carboxylated Acrylic Polymers as Studied by Pulsed Field Gradient NMR. 1. Solvent Diffusion Studies. JOURNAL OF POLYMER RESEARCH 2007. [DOI: 10.1007/s10965-006-9087-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Lafitte G, Söderman O, Thuresson K, Davies J. PFG-NMR diffusometry: A tool for investigating the structure and dynamics of noncommercial purified pig gastric mucin in a wide range of concentrations. Biopolymers 2007; 86:165-75. [PMID: 17345632 DOI: 10.1002/bip.20717] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
For the first time, Pulsed Field Gradient-Nuclear Magnetic Resonance, a powerful noninvasive tool for studying the dynamics and structure of complex gels, has been used to measure diffusion of probe molecules in aqueous solutions/gels of noncommercial purified pig gastric mucin (PGM), in a concentration range up to 5 wt %. Complementary data were obtained from rheology measurements. The combination of techniques revealed a strong pH dependency of the structure of the PGM samples while changes in concentration, ionic strength, and temperature appeared to induce less pronounced alterations. Viscosity was found to vary in a nonmonotonous way with pH, with the more viscous solutions found at intermediate pH. We propose that this finding is due to a reduced charge density at lower pH, which is expected to continuously increase the relative importance of hydrophobic associations. The results suggest a loose network of expanded fully charged PGM molecules with considerable mobility at neutral pH (pH 7.4). At intermediate pH (pH 4), a three-dimensional expanded network is favored. At pH 1, the charge density is low and microphase separation occurs since hydrophobic associations prevail. This leads to the formation of clusters concentrated in PGM molecules separated by regions depleted in PGM. The results obtained increase our knowledge about the gastric mucosal layer, which in vivo contains mucin in the same concentration range as that of the samples investigated here.
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Affiliation(s)
- G Lafitte
- Physical Chemistry I, Center for Chemistry and Chemical Engineering, Lund University, PO Box 124, SE-221 00 Lund, Sweden.
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17
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Bardakci M, Tillich JE, Holz M. Characterization of Structure and Transport in Porous Media by Pulsed Field Gradient (PFG) NMR Technique. Part I: Master Curve and Characteristic Inner Length. Chem Eng Technol 2006. [DOI: 10.1002/ceat.200600043] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Colsenet R, Söderman O, Mariette F. Pulsed Field Gradient NMR Study of Poly(ethylene glycol) Diffusion in Whey Protein Solutions and Gels. Macromolecules 2006. [DOI: 10.1021/ma0519922] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Roxane Colsenet
- Cemagref, Process Engineering Technology Research Unit, CS 64426, 17 avenue de Cucillé, 35044 Rennes, Cedex, France, and Physical Chemistry 1, Chemical Center, University of Lund, P.O. Box 124, S-22100 Lund, Sweden
| | - Olle Söderman
- Cemagref, Process Engineering Technology Research Unit, CS 64426, 17 avenue de Cucillé, 35044 Rennes, Cedex, France, and Physical Chemistry 1, Chemical Center, University of Lund, P.O. Box 124, S-22100 Lund, Sweden
| | - François Mariette
- Cemagref, Process Engineering Technology Research Unit, CS 64426, 17 avenue de Cucillé, 35044 Rennes, Cedex, France, and Physical Chemistry 1, Chemical Center, University of Lund, P.O. Box 124, S-22100 Lund, Sweden
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Fechete R, Demco DE, Eliav U, Blümich B, Navon G. Self-diffusion anisotropy of water in sheep Achilles tendon. NMR IN BIOMEDICINE 2005; 18:577-86. [PMID: 16320373 DOI: 10.1002/nbm.995] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
The principal values of the diffusion tensor of free water in the pores of sheep Achilles tendon were determined. For this purpose, the azimuthally angular dependence of the self-diffusion coefficient was measured using a radiofrequency tilt coil and pulsed-field-gradient stimulated-echo (PFGSE) NMR. Combining the PFGSE with multiple acquisitions of Hahn echoes using the Carr-Purcell-Meiboom-Gill pulse sequence reduced the measuring time. The diffusion measurements revealed two diffusion process characterized by a fast and a slow effective diffusion coefficient. A model which describes the stimulated-echo amplitude, encoded by the water diffusion and magnetization transfer, was used for evaluation of the fast diffusion coefficients. The fast diffusion process characterizes the water molecules in pores surrounding the collagen fibrils. The diffusion coefficients characterizing the fast process show a well-defined anisotropy. The principal values of the diffusion tensors were determined assuming the elongated pores to be oriented parallel to the tendon fibrils and thus the orientation distribution function of the pores followed that of the collagen fibrils. The average aspect ratio of pores was estimated from the principal values of the water diffusion tensor and is suitable to characterize quantitatively the changes in tendon morphology due to healing or aging. The methods in this investigation can also be applied to measurements of the diffusion anisotropy using ex situ NMR sensors.
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Affiliation(s)
- R Fechete
- Institut für Technische Chemie und Makromolekulare Chemie, Rheinisch-Westfälische Technische Hochschule, Worringerweg 1, D-52056 Aachen, Germany
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Colsenet R, Soderman O, Mariette F. Effect of Casein Concentration in Suspensions and Gels on Poly(ethylene glycol)s NMR Self-Diffusion Measurements. Macromolecules 2005. [DOI: 10.1021/ma051294h] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Roxane Colsenet
- Process Engineering Technology Research Unit, Cemagref, CS 64426, 17 avenue de Cucillé, 35044 Rennes, Cedex, France, and Physical Chemistry 1, Chemical Center, University of Lund, P.O. Box 124, S-22100 Lund, Sweden
| | - Olle Soderman
- Process Engineering Technology Research Unit, Cemagref, CS 64426, 17 avenue de Cucillé, 35044 Rennes, Cedex, France, and Physical Chemistry 1, Chemical Center, University of Lund, P.O. Box 124, S-22100 Lund, Sweden
| | - François Mariette
- Process Engineering Technology Research Unit, Cemagref, CS 64426, 17 avenue de Cucillé, 35044 Rennes, Cedex, France, and Physical Chemistry 1, Chemical Center, University of Lund, P.O. Box 124, S-22100 Lund, Sweden
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21
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Mohamed EE, Gröger S, Schiller J, Stallmach F, Kärger J, Arnold K. The self-diffusion behavior of polyethylene glycol in cartilageas studied by pulsed-field gradient NMR. Phys Med 2005; 21:69-73. [DOI: 10.1016/s1120-1797(05)80022-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/17/2005] [Revised: 03/04/2005] [Accepted: 03/15/2005] [Indexed: 11/30/2022] Open
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22
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Shikii K, Seki H, Sakamoto S, Sei Y, Utsumi H, Yamaguchi K. Intermolecular Hydrogen Bonding of Steroid Compounds: PFG NMR Diffusion Study, Cold-Spray Ionization (CSI)-MS and X-Ray Analysis. Chem Pharm Bull (Tokyo) 2005; 53:792-5. [PMID: 15997137 DOI: 10.1248/cpb.53.792] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
An extensive analysis of hydrogen bonding of steroid compounds in diluted solution is preformed by pulsed field gradient (PFG) NMR and cold-spray ionization (CSI)-MS, in the solid state by X-ray crystallographic analysis. The formation of hydrogen bond interaction are quantified and discussed. Although X-ray analysis in the crystalline state and CSI-MS measurement in solution suggested that the observed diffusion coefficient D(obs) of the steroid compounds may vary in accordance with the number of hydrogen bonds, the actual observed D(obs) value determined from the diffusion studies diminished constantly without correlation on the decreasing numbers of hydrogen bonds. Comparison of two different calibration profiles of calculated molecular volume (V(cal)) vs. D(obs), which are obtained from compounds possessing no hydrogen bonding and the steroid compounds, formation of a chain structure (cluster) based on intermolecular hydrogen bonding of the steroid compounds is unambiguously confirmed.
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Affiliation(s)
- Kazuaki Shikii
- Chemical Analysis Center, Chiba University, Chiba, Japan
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Multicomponent diffusion in phase-separating polymer blends with different frictional interactions: a mean-friction model. Chem Eng Sci 2003. [DOI: 10.1016/s0009-2509(03)00313-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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25
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Naji L, Schiller J, Kaufmann J, Stallmach F, Kärger J, Arnold K. The gel-forming behaviour of dextran in the presence of KCl: a quantitative 13C and pulsed field gradient (PFG) NMR study. Biophys Chem 2003; 104:131-40. [PMID: 12834833 DOI: 10.1016/s0301-4622(02)00362-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Although the gel forming ability of certain polysaccharides in the presence of ions is a well-known phenomenon, detailed physicochemical mechanisms of such processes are still unknown. In this investigation high resolution 13C NMR as well as 1H pulsed field gradient (PFG) NMR were used to investigate the mobility of dextran in the sol and in the gel state. Gel-formation of dextran can be easily induced by the addition of large amounts of potassium chloride. No major differences in the T(1) relaxation times of dextran in the sol and in the gel state could be observed. Accordingly, the analysis of the 13C NMR spectroscopic data did not provide any indication of an observable line-broadening upon gel-formation. However, a KCl concentration dependent decrease of signal intensity in comparison to an internal standard was detected. On the other hand, the PFG NMR studies clearly indicated a gradual diminution of the self-diffusion coefficient of the dextran with increasing molecular weight as well as in the presence of potassium chloride. These measurements revealed in agreement with spectroscopic data that at least one potassium ion per monomer subunit (i.e. one glycopyranose residue) is necessary for gel formation.
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Affiliation(s)
- L Naji
- Institute of Medical Physics and Biophysics, Medical Faculty, University of Leipzig, Liebigstr. 27, D-04103 Leipzig, Germany
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