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Lu X, Sun H, Chang T, Zhang J, Cui H. Terahertz detection of porosity and porous microstructure in pharmaceutical tablets: A review. Int J Pharm 2020; 591:120006. [DOI: 10.1016/j.ijpharm.2020.120006] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2020] [Revised: 10/15/2020] [Accepted: 10/18/2020] [Indexed: 12/14/2022]
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Marr N, Hopkinson M, Hibbert AP, Pitsillides AA, Thorpe CT. Bimodal Whole-Mount Imaging of Tendon Using Confocal Microscopy and X-ray Micro-Computed Tomography. Biol Proced Online 2020; 22:13. [PMID: 32624710 PMCID: PMC7329428 DOI: 10.1186/s12575-020-00126-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2020] [Accepted: 06/21/2020] [Indexed: 12/25/2022] Open
Abstract
Background Three-dimensional imaging modalities for optically dense connective tissues such as tendons are limited and typically have a single imaging methodological endpoint. Here, we have developed a bimodal procedure utilising fluorescence-based confocal microscopy and x-ray micro-computed tomography for the imaging of adult tendons to visualise and analyse extracellular sub-structure and cellular composition in small and large animal species. Results Using fluorescent immunolabelling and optical clearing, we visualised the expression of the novel cross-species marker of tendon basement membrane, laminin-α4 in 3D throughout whole rat Achilles tendons and equine superficial digital flexor tendon 5 mm segments. This revealed a complex network of laminin-α4 within the tendon core that predominantly localises to the interfascicular matrix compartment. Furthermore, we implemented a chemical drying process capable of creating contrast densities enabling visualisation and quantification of both fascicular and interfascicular matrix volume and thickness by x-ray micro-computed tomography. We also demonstrated that both modalities can be combined using reverse clarification of fluorescently labelled tissues prior to chemical drying to enable bimodal imaging of a single sample. Conclusions Whole-mount imaging of tendon allowed us to identify the presence of an extensive network of laminin-α4 within tendon, the complexity of which cannot be appreciated using traditional 2D imaging techniques. Creating contrast for x-ray micro-computed tomography imaging of tendon using chemical drying is not only simple and rapid, but also markedly improves on previously published methods. Combining these methods provides the ability to gain spatio-temporal information and quantify tendon substructures to elucidate the relationship between morphology and function.
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Affiliation(s)
- Neil Marr
- Comparative Biomedical Sciences, Royal Veterinary College, Royal College Street, London, UK
| | - Mark Hopkinson
- Comparative Biomedical Sciences, Royal Veterinary College, Royal College Street, London, UK
| | - Andrew P Hibbert
- Comparative Biomedical Sciences, Royal Veterinary College, Royal College Street, London, UK
| | - Andrew A Pitsillides
- Comparative Biomedical Sciences, Royal Veterinary College, Royal College Street, London, UK
| | - Chavaunne T Thorpe
- Comparative Biomedical Sciences, Royal Veterinary College, Royal College Street, London, UK
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Ma Y, Qi M, An Y, Zhang L, Yang R, Doro DH, Liu W, Jin Y. Autophagy controls mesenchymal stem cell properties and senescence during bone aging. Aging Cell 2018; 17. [PMID: 29210174 PMCID: PMC5770781 DOI: 10.1111/acel.12709] [Citation(s) in RCA: 226] [Impact Index Per Article: 37.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/14/2017] [Indexed: 12/22/2022] Open
Abstract
Bone marrow‐derived mesenchymal stem cells (BMMSCs) exhibit degenerative changes, including imbalanced differentiation and reduced proliferation during aging, that contribute to age‐related bone loss. We demonstrate here that autophagy is significantly reduced in aged BMMSCs compared with young BMMSCs. The autophagy inhibitor 3‐methyladenine (3‐MA) could turn young BMMSCs into a relatively aged state by reducing their osteogenic differentiation and proliferation capacity and enhancing their adipogenic differentiation capacity. Accordingly, the autophagy activator rapamycin could restore the biological properties of aged BMMSCs by increasing osteogenic differentiation and proliferation capacity and decreasing adipogenic differentiation capacity. Possible underlying mechanisms were explored, and the analysis revealed that autophagy could affect reactive oxygen species and p53 levels, thus regulating biological properties of BMMSCs. In an in vivo study, we found that activation of autophagy restored bone loss in aged mice. In conclusion, our results suggest that autophagy plays a pivotal role in the aging of BMMSCs, and activation of autophagy could partially reverse this aging and may represent a potential therapeutic avenue to clinically treat age‐related bone loss.
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Affiliation(s)
- Yang Ma
- State Key Laboratory of Military Stomatology & National Clinical Research Center for Oral Diseases & Shaanxi International Joint Research Center for Oral Diseases; Center for Tissue Engineering; School of Stomatology; The Fourth Military Medical University; Xi'an Shaanxi China
- Department of Craniofacial Development and Stem Cell Biology; Dental Institute; Kings College London; London UK
| | - Meng Qi
- State Key Laboratory of Military Stomatology & National Clinical Research Center for Oral Diseases & Shaanxi International Joint Research Center for Oral Diseases; Center for Tissue Engineering; School of Stomatology; The Fourth Military Medical University; Xi'an Shaanxi China
| | - Ying An
- State Key Laboratory of Military Stomatology & National Clinical Research Center for Oral Diseases & Shaanxi International Joint Research Center for Oral Diseases; Center for Tissue Engineering; School of Stomatology; The Fourth Military Medical University; Xi'an Shaanxi China
- State Key Laboratory of Military Stomatology & National Clinical Research Center for Oral Diseases & Shaanxi International Joint Research Center for Oral Diseases; Department of Periodontology; School of Stomatology; The Fourth Military Medical University; Xi'an Shaanxi China
| | - Liqiang Zhang
- State Key Laboratory of Military Stomatology & National Clinical Research Center for Oral Diseases & Shaanxi International Joint Research Center for Oral Diseases; Center for Tissue Engineering; School of Stomatology; The Fourth Military Medical University; Xi'an Shaanxi China
- Xi'an Institute of Tissue Engineering & Regenerative Medicine; Xi'an Shaanxi China
| | - Rui Yang
- State Key Laboratory of Military Stomatology & National Clinical Research Center for Oral Diseases & Shaanxi International Joint Research Center for Oral Diseases; Center for Tissue Engineering; School of Stomatology; The Fourth Military Medical University; Xi'an Shaanxi China
- Department of Stomatology; PLA Army General Hospital; Beijing China
| | - Daniel H Doro
- Department of Craniofacial Development and Stem Cell Biology; Dental Institute; Kings College London; London UK
| | - Wenjia Liu
- State Key Laboratory of Military Stomatology & National Clinical Research Center for Oral Diseases & Shaanxi International Joint Research Center for Oral Diseases; Center for Tissue Engineering; School of Stomatology; The Fourth Military Medical University; Xi'an Shaanxi China
- Xi'an Institute of Tissue Engineering & Regenerative Medicine; Xi'an Shaanxi China
| | - Yan Jin
- State Key Laboratory of Military Stomatology & National Clinical Research Center for Oral Diseases & Shaanxi International Joint Research Center for Oral Diseases; Center for Tissue Engineering; School of Stomatology; The Fourth Military Medical University; Xi'an Shaanxi China
- Xi'an Institute of Tissue Engineering & Regenerative Medicine; Xi'an Shaanxi China
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Markl D, Strobel A, Schlossnikl R, Bøtker J, Bawuah P, Ridgway C, Rantanen J, Rades T, Gane P, Peiponen KE, Zeitler JA. Characterisation of pore structures of pharmaceutical tablets: A review. Int J Pharm 2018; 538:188-214. [PMID: 29341913 DOI: 10.1016/j.ijpharm.2018.01.017] [Citation(s) in RCA: 66] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2017] [Revised: 01/03/2018] [Accepted: 01/05/2018] [Indexed: 10/18/2022]
Abstract
Traditionally, the development of a new solid dosage form is formulation-driven and less focus is put on the design of a specific microstructure for the drug delivery system. However, the compaction process particularly impacts the microstructure, or more precisely, the pore architecture in a pharmaceutical tablet. Besides the formulation, the pore structure is a major contributor to the overall performance of oral solid dosage forms as it directly affects the liquid uptake rate, which is the very first step of the dissolution process. In future, additive manufacturing is a potential game changer to design the inner structures and realise a tailor-made pore structure. In pharmaceutical development the pore structure is most commonly only described by the total porosity of the tablet matrix. Yet it is of great importance to consider other parameters to fully resolve the interplay between microstructure and dosage form performance. Specifically, tortuosity, connectivity, as well as pore shape, size and orientation all impact the flow paths and play an important role in describing the fluid flow in a pharmaceutical tablet. This review presents the key properties of the pore structures in solid dosage forms and it discusses how to measure these properties. In particular, the principles, advantages and limitations of helium pycnometry, mercury porosimetry, terahertz time-domain spectroscopy, nuclear magnetic resonance and X-ray computed microtomography are discussed.
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Affiliation(s)
- Daniel Markl
- Department of Chemical Engineering and Biotechnology, University of Cambridge, Philippa Fawcett Drive, CB3 0AS Cambridge, UK.
| | - Alexa Strobel
- Department of Chemical Engineering and Biotechnology, University of Cambridge, Philippa Fawcett Drive, CB3 0AS Cambridge, UK
| | - Rüdiger Schlossnikl
- Department of Chemical Engineering and Biotechnology, University of Cambridge, Philippa Fawcett Drive, CB3 0AS Cambridge, UK
| | - Johan Bøtker
- Department of Pharmacy, University of Copenhagen, Universitetsparken 2, DK-2100 Copenhagen, Denmark
| | - Prince Bawuah
- School of Pharmacy, Promis Centre, University of Eastern Finland, P.O. Box 1617, FI-70211 Kuopio, Finland
| | - Cathy Ridgway
- Omya International AG, CH-4665 Oftringen, Switzerland
| | - Jukka Rantanen
- Department of Pharmacy, University of Copenhagen, Universitetsparken 2, DK-2100 Copenhagen, Denmark
| | - Thomas Rades
- Department of Pharmacy, University of Copenhagen, Universitetsparken 2, DK-2100 Copenhagen, Denmark
| | - Patrick Gane
- Omya International AG, CH-4665 Oftringen, Switzerland; School of Chemical Technology, Department of Bioproducts and Biosystems, Aalto University, FI-00076 Aalto, Helsinki, Finland
| | - Kai-Erik Peiponen
- Institute of Photonics, University of Eastern Finland, P.O. Box 111, FI-80101 Joensuu, Finland
| | - J Axel Zeitler
- Department of Chemical Engineering and Biotechnology, University of Cambridge, Philippa Fawcett Drive, CB3 0AS Cambridge, UK
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Krishnakumar SB, Podgorsak AR, Nagesh SS, Jain A, Rudin S, Bednarek DR, Ionita CN. Investigation of Noise and Contrast Sensitivity of an Electron Multiplying Charge-Coupled Device (EMCCD) based Cone Beam Micro-CT System. PROCEEDINGS OF SPIE--THE INTERNATIONAL SOCIETY FOR OPTICAL ENGINEERING 2016. [PMID: 28638172 DOI: 10.1117/12.2216794] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
A small animal micro-CT system was built using an EMCCD detectors having complex pre-digitization amplification technology, high-resolution, high-sensitivity and low-noise. Noise in CBCT reconstructed images when using pre-digitization amplification behaves differently than commonly used detectors and warrants a detailed investigation. In this study, noise power and contrast sensitivity were estimated for the newly built system. Noise analysis was performed by scanning a water phantom. Tube voltage was lowered to minimum delivered by the tube (20 kVp and 0.5 mA) and detector gain was varied. Contrast sensitivity was analyzed by using a phantom containing different iodine contrast solutions (20% to 70%) filled in six different tubes. First, we scanned the phantom using various x-ray exposures at 40 kVp while changing the gain to maintain the background air value of the projection images constant. Next, the exposure was varied while the detector gain was maintained constant. Radial NPS plots show that noise power level increases as gain increases. Contrast sensitivity was analyzed by calculating ratio of signal-to-noise ratios (SNR) for increased gain with those of low constant gain at each exposure. The SNR value at low constant gain was always lower than SNR of high detector gain at all x-ray settings and iodine contrast. The largest increase of SNR approached 1.3 for low contrast feature for an iodine concentration of 20%. Despite an increase in noise level as gain increases, the SNR improvement shows that signal level also increases because of the unique on-chip gain of the detector.
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Affiliation(s)
- Sumukh Bysani Krishnakumar
- Department of Biomedical Engineering, State University of New York at Buffalo.,Toshiba Stroke and Vascular Research Center, Buffalo, NY
| | - Alexander R Podgorsak
- Department of Biomedical Engineering, State University of New York at Buffalo.,Toshiba Stroke and Vascular Research Center, Buffalo, NY
| | | | - Amit Jain
- Toshiba Stroke and Vascular Research Center, Buffalo, NY
| | - Stephen Rudin
- Department of Biomedical Engineering, State University of New York at Buffalo.,Toshiba Stroke and Vascular Research Center, Buffalo, NY
| | | | - Ciprian N Ionita
- Department of Biomedical Engineering, State University of New York at Buffalo.,Toshiba Stroke and Vascular Research Center, Buffalo, NY
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Hachaj T. Real time exploration and management of large medical volumetric datasets on small mobile devices—Evaluation of remote volume rendering approach. INTERNATIONAL JOURNAL OF INFORMATION MANAGEMENT 2014. [DOI: 10.1016/j.ijinfomgt.2013.11.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Yagi M, Arentsen L, Shanley RM, Rosen CJ, Kidder LS, Sharkey LC, Yee D, Koizumi M, Ogawa K, Hui SK. A dual-radioisotope hybrid whole-body micro-positron emission tomography/computed tomography system reveals functional heterogeneity and early local and systemic changes following targeted radiation to the murine caudal skeleton. Calcif Tissue Int 2014; 94:544-52. [PMID: 24562595 PMCID: PMC3987955 DOI: 10.1007/s00223-014-9839-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/30/2013] [Accepted: 01/17/2014] [Indexed: 12/27/2022]
Abstract
The purpose of this study was to develop a longitudinal non-invasive functional imaging method using a dual-radioisotope hybrid micro-positron emission tomography/computed tomography (PET/CT) scanner in order to assess both the skeletal metabolic heterogeneity and the effect of localized radiation that models therapeutic cancer treatment on marrow and bone metabolism. Skeletally mature BALB/c female mice were given clinically relevant local radiation (16 Gy) to the hind limbs on day 0. Micro-PET/CT acquisition was performed serially for the same mice on days -5 and +2 with FDG and days -4 and +3 with NaF. Serum levels of pro-inflammatory cytokines were measured. Significant differences (p < 0.0001) in marrow metabolism (measured by FDG) and bone metabolism (measured by NaF) were observed among bones before radiation, which demonstrates functional heterogeneity in the marrow and mineralized bone throughout the skeleton. Radiation significantly (p < 0.0001) decreased FDG uptake but increased NaF uptake (p = 0.0314) in both irradiated and non-irradiated bones at early time points. An increase in IL-6 was observed with a significant abscopal (distant) effect on marrow and bone metabolic function. Radiation significantly decreased circulating IGF-1 (p < 0.01). Non-invasive longitudinal imaging with dual-radioisotope micro-PET/CT is feasible to investigate simultaneous changes in marrow and bone metabolic function at local and distant skeletal sites in response to focused radiation injury. Distinct local and remote changes may be affected by several cytokines activated early after local radiation exposure. This approach has the potential for longer-term studies to clarify the effects of radiation on marrow and bone.
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Affiliation(s)
- Masashi Yagi
- Masonic Cancer Center, University of Minnesota, Minneapolis, MN, USA
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