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Budai L, Budai M, Fülöpné Pápay ZE, Vilimi Z, Antal I. Rheological Considerations of Pharmaceutical Formulations: Focus on Viscoelasticity. Gels 2023; 9:469. [PMID: 37367140 DOI: 10.3390/gels9060469] [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: 05/09/2023] [Revised: 05/26/2023] [Accepted: 06/01/2023] [Indexed: 06/28/2023] Open
Abstract
Controlling rheological properties offers the opportunity to gain insight into the physical characteristics, structure, stability and drug release rate of formulations. To better understand the physical properties of hydrogels, not only rotational but also oscillatory experiments should be performed. Viscoelastic properties, including elastic and viscous properties, are measured using oscillatory rheology. The gel strength and elasticity of hydrogels are of great importance for pharmaceutical development as the application of viscoelastic preparations has considerably expanded in recent decades. Viscosupplementation, ophthalmic surgery and tissue engineering are just a few examples from the wide range of possible applications of viscoelastic hydrogels. Hyaluronic acid, alginate, gellan gum, pectin and chitosan are remarkable representatives of gelling agents that attract great attention applied in biomedical fields. This review provides a brief summary of rheological properties, highlighting the viscoelasticity of hydrogels with great potential in biomedicine.
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Affiliation(s)
- Lívia Budai
- Department of Pharmaceutics, Semmelweis University, 1092 Budapest, Hungary
| | - Marianna Budai
- Department of Pharmaceutics, Semmelweis University, 1092 Budapest, Hungary
| | | | - Zsófia Vilimi
- Department of Pharmaceutics, Semmelweis University, 1092 Budapest, Hungary
| | - István Antal
- Department of Pharmaceutics, Semmelweis University, 1092 Budapest, Hungary
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Cutolo F, Meola A, Carbone M, Sinceri S, Cagnazzo F, Denaro E, Esposito N, Ferrari M, Ferrari V. A new head-mounted display-based augmented reality system in neurosurgical oncology: a study on phantom. Comput Assist Surg (Abingdon) 2017; 22:39-53. [PMID: 28754068 DOI: 10.1080/24699322.2017.1358400] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022] Open
Affiliation(s)
- Fabrizio Cutolo
- Department of Translational Research and New Technologies in Medicine and Surgery, EndoCAS Center, University of Pisa, Pisa, Italy
- Department of Information Engineering, University of Pisa, Pisa, Italy
| | - Antonio Meola
- Department of Neurosurgery, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Marina Carbone
- Department of Translational Research and New Technologies in Medicine and Surgery, EndoCAS Center, University of Pisa, Pisa, Italy
| | - Sara Sinceri
- Department of Translational Research and New Technologies in Medicine and Surgery, EndoCAS Center, University of Pisa, Pisa, Italy
| | | | - Ennio Denaro
- Department of Translational Research and New Technologies in Medicine and Surgery, EndoCAS Center, University of Pisa, Pisa, Italy
| | - Nicola Esposito
- Department of Translational Research and New Technologies in Medicine and Surgery, EndoCAS Center, University of Pisa, Pisa, Italy
| | - Mauro Ferrari
- Department of Translational Research and New Technologies in Medicine and Surgery, EndoCAS Center, University of Pisa, Pisa, Italy
- Department of Vascular Surgery, Pisa University Medical School, Pisa, Italy
| | - Vincenzo Ferrari
- Department of Translational Research and New Technologies in Medicine and Surgery, EndoCAS Center, University of Pisa, Pisa, Italy
- Department of Information Engineering, University of Pisa, Pisa, Italy
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Strohm EM, Wirtzfeld LA, Czarnota GJ, Kolios MC. High frequency ultrasound imaging and simulations of sea urchin oocytes. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2017; 142:268. [PMID: 28764480 DOI: 10.1121/1.4993594] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
High frequency ultrasound backscatter signals from sea urchin oocytes were measured using a 40 MHz transducer and compared to numerical simulations. The Faran scattering model was used to calculate the ultrasound scattered from single oocytes in suspension. The urchin oocytes are non-nucleated with uniform size and biomechanical properties; the backscatter from each cell is similar and easy to simulate, unlike typical nucleated mammalian cells. The time domain signal measured from single oocytes in suspension showed two distinct peaks, and the power spectrum was periodic with minima spaced approximately 10 MHz apart. Good agreement to the Faran scattering model was observed. Measurements from tightly packed oocyte cell pellets showed similar periodic features in the power spectra, which was a result of the uniform size and consistent biomechanical properties of the cells. Numerical simulations that calculated the ultrasound scattered from individual oocytes within a three dimensional volume showed good agreement to the measured signals and B-scan images. A cepstral analysis of the signal was used to calculate the size of the cells, which was 78.7 μm (measured) and 81.4 μm (simulated). This work supports the single scattering approximation, where ultrasound is discretely scattered from single cells within a bulk homogeneous sample, and that multiple scattering has a negligible effect. This technique can be applied towards understanding the complex scattering behaviour from heterogeneous tissues.
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Affiliation(s)
- Eric M Strohm
- Department of Physics, Ryerson University, 350 Victoria Street, Toronto, Ontario M5B 2K3, Canada
| | - Lauren A Wirtzfeld
- Department of Physics, Ryerson University, 350 Victoria Street, Toronto, Ontario M5B 2K3, Canada
| | - Gregory J Czarnota
- Senior Scientist and Director, Odette Cancer Research Program, Sunnybrook Research Institute, 2075 Bayview Avenue, Toronto, Ontario M4N 3M5, Canada
| | - Michael C Kolios
- Department of Physics, Ryerson University, 350 Victoria Street, Toronto, Ontario M5B 2K3, Canada
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Lanata A, Guidi A, Baragli P, Paradiso R, Valenza G, Scilingo EP. Removing movement artifacts from equine ECG recordings acquired with textile electrodes. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2016; 2015:1955-8. [PMID: 26736667 DOI: 10.1109/embc.2015.7318767] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
This study reports on the implementation of a novel system to detect and reduce movement artifact (MA) contribution in electrocardiogram (ECG) recordings acquired from horses in free movement conditions. The system comprises both integrated textile electrodes for ECG acquisition and one triaxial accelerometer for movement monitoring. Here, ECG and physical activity are continuously acquired from seven horses through the wearable system and a model that integrates cardiovascular and movement information to estimate the MA contribution is implemented. Moreover, in this study we propose a new algorithm where the Stationary Wavelet Transform (SWT) decomposition algorithm is employed to identify and remove movement artifacts from ECG recodigns. Achieved results showed a reduction of MA percentage greater than 40% between before- and after- the application of the proposed algorithm to seven hours of recordings.
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Kazimierska-Drobny K, El Fray M, Kaczmarek M. Determination of mechanical and hydraulic properties of PVA hydrogels. MATERIALS SCIENCE & ENGINEERING. C, MATERIALS FOR BIOLOGICAL APPLICATIONS 2015; 48:48-54. [DOI: 10.1016/j.msec.2014.11.034] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2014] [Revised: 10/07/2014] [Accepted: 11/10/2014] [Indexed: 11/16/2022]
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Lanata A, Greco A, Valenza G, Scilingo EP. On the tridimensional estimation of the gaze point by a stereoscopic wearable eye tracker. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2015; 2015:2283-2286. [PMID: 26736748 DOI: 10.1109/embc.2015.7318848] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
This paper reports a novel stereo-vision-method (binocular system-geometrical mapped (BS-GM)) to estimate the depth coordinates of the eye gaze point in a controlled 3D space of vision. The method outcomes were compared in both 2D and 3D visual targets with both mono- and stereo-vision algorithms in order to estimate accuracy of results. More specifically, we compared BS-GM with a monocular method and with two stereo-vision methodologies which were different in order to the mapping functions. All of the methods were implemented in the same head mounted eye tracking system able to acquire both eyes. In 2D visual space (i.e. plane of vision) we compared BS-GM with a monocular method, a binocular system-linear mapped (BS-LM) and a binocular system-quadratic mapped (BS-QM). In the 3D space estimation all of the binocular systems were compared each other. Thirteen enrolled subjects observed 31 targets of known coordinates in a controlled environment. Results achieved on 2D comparison showed no statistical significant difference among the four methods, while the comparison on 3D space of vision showed that BS-GM method achieved a significant better accuracy than BS-LM and BS-QM method. Specifically, BS-GM showed and average percentage error obit of 3.47%.
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Pradny M, Vetrik M, Hruby M, Michalek J. Biodegradable Porous Hydrogels. Adv Healthc Mater 2014. [DOI: 10.1002/9781118774205.ch8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Xia W, Piras D, Heijblom M, Steenbergen W, van Leeuwen TG, Manohar S. Poly(vinyl alcohol) gels as photoacoustic breast phantoms revisited. JOURNAL OF BIOMEDICAL OPTICS 2011; 16:075002. [PMID: 21806259 DOI: 10.1117/1.3597616] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
A popular phantom in photoacoustic imaging is poly(vinyl alcohol) (PVA) hydrogel fabricated by freezing and thawing (F-T) aqueous solutions of PVA. The material possesses acoustic and optical properties similar to those of tissue. Earlier work characterized PVA gels in small test specimens where temperature distributions during F-T are relatively homogeneous. In this work, in breast-sized samples we observed substantial temperature differences between the shallow regions and the interior during the F-T procedure. We investigated whether spatial variations were also present in the acoustic and optical properties. The speed of sound, acoustic attenuation, and optical reduced scattering coefficients were measured on specimens sampled at various locations in a large phantom. In general, the properties matched values quoted for breast tissue. But while acoustic properties were relatively homogeneous, the reduced scattering was substantially different at the surface compared with the interior. We correlated these variations with gel microstructure inspected using scanning electron microscopy. Interestingly, the phantom's reduced scattering spatial distribution matches the optical properties of the standard two-layer breast model used in x ray dosimetry. We conclude that large PVA samples prepared using the standard recipe make excellent breast tissue phantoms.
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Affiliation(s)
- Wenfeng Xia
- University of Twente, Biomedical Photonic Imaging group, Mira Institute for Biomedical Technology and Technical Medicine, P.O. Box 217, 7500AE Enschede, The Netherlands
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