Dynamics of laser induced thermoelastic expansion of native and coagulated ex-vivo soft tissue samples and their optical and thermo-mechanical properties

Author(s):  
Behrouz Soroushian ◽  
William M. Whelan ◽  
Michael C. Kolios
2006 ◽  
Vol 975 ◽  
Author(s):  
Amanpreet Kaur Bembey ◽  
Michelle L Oyen ◽  
Virginia L. Ferguson ◽  
Andrew J. Bushby ◽  
Alan Boyde

ABSTRACTIn the current study, the effects of polar solvents on tissue volume and mechanical properties are considered. Area shrinkage measurements are conducted for mineralized, bone tissue samples soaked in polar solvents. Area shrinkage is used to calculate approximate linear and volume shrinkage. Results are compared with viscoelastic mechanical parameters for bone in the same solvents (as measured previously) and with both shrinkage measurements and mechanical data for nonmineralized tissues, as taken from the existing literature. As expected, the shrinkage of mineralized tissues is minimal when compared with shrinkage of nonmineralized tissues immersed in the same polar solvents. The mechanical changes in bone are also substantially less than in nonmineralized tissues. The largest stiffness values are found in shrunken bone samples (immersed in acetone and ethanol). The mineral phase in bone thus resists tissue shrinkage that would otherwise occur in the pure soft tissue phase.


2018 ◽  
Vol 25 (4) ◽  
pp. 1153-1161 ◽  
Author(s):  
Mara Saccomano ◽  
Jonas Albers ◽  
Giuliana Tromba ◽  
Marina Dobrivojević Radmilović ◽  
Srećko Gajović ◽  
...  

Synchrotron radiation micro-computed tomography (SRµCT) based virtual histology, in combination with dedicated ex vivo staining protocols and/or phase contrast, is an emerging technology that makes use of three-dimensional images to provide novel insights into the structure of tissue samples at microscopic resolution with short acquisition times of the order of minutes or seconds. However, the high radiation dose creates special demands on sample preparation and staining. As a result of the lack of specific staining in virtual histology, it can supplement but not replace classical histology. Therefore, the aim of this study was to establish and compare optimized ex vivo staining and acquisition protocols for SRµCT-based virtual histology of soft-tissue samples, which could be integrated into the standard workflow of classical histology. The high grade of coherence of synchrotron radiation allows the application of propagation-based phase contrast imaging (PBI). In this study, PBI yielded a strong increase in image quality even at lower radiation doses and consequently prevented any damage to the tissue samples or the embedding material. This work has demonstrated that the improvement in contrast-to-noise ratio by PBI enabled label-free virtual histology of soft-tissue specimens embedded in paraffin to a level of detail that exceeds that achieved with staining protocols.


2016 ◽  
Vol 11 (03) ◽  
pp. C03005-C03005 ◽  
Author(s):  
J. Dudak ◽  
J. Zemlicka ◽  
F. Krejci ◽  
J. Karch ◽  
M. Patzelt ◽  
...  
Keyword(s):  
Ex Vivo ◽  

IEEE Access ◽  
2021 ◽  
Vol 9 ◽  
pp. 14599-14607
Author(s):  
Jianan Wu ◽  
Zhihui Qian ◽  
Ruixia Xu ◽  
Jing Liu ◽  
Luquan Ren ◽  
...  

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Mary Beth Wandel ◽  
Craig A. Bell ◽  
Jiayi Yu ◽  
Maria C. Arno ◽  
Nathan Z. Dreger ◽  
...  

AbstractComplex biological tissues are highly viscoelastic and dynamic. Efforts to repair or replace cartilage, tendon, muscle, and vasculature using materials that facilitate repair and regeneration have been ongoing for decades. However, materials that possess the mechanical, chemical, and resorption characteristics necessary to recapitulate these tissues have been difficult to mimic using synthetic resorbable biomaterials. Herein, we report a series of resorbable elastomer-like materials that are compositionally identical and possess varying ratios of cis:trans double bonds in the backbone. These features afford concomitant control over the mechanical and surface eroding degradation properties of these materials. We show the materials can be functionalized post-polymerization with bioactive species and enhance cell adhesion. Furthermore, an in vivo rat model demonstrates that degradation and resorption are dependent on succinate stoichiometry in the elastomers and the results show limited inflammation highlighting their potential for use in soft tissue regeneration and drug delivery.


2021 ◽  
Vol 38 ◽  
pp. 6-12
Author(s):  
R.J. Samson ◽  
F.H. Mpagike ◽  
A.K. Felix ◽  
A.B. Matondo ◽  
M. Makungu

A seven-year-old female mongrel dog was presented at the Sokoine University of Agriculture Teaching Animal Hospital for second opinion regarding a progressive swelling of the right hind limb of two months duration. Clinical examination revealed a loss of body condition, tachypnea and tachycardia, a painful immobile solid mass of 20 cm x 14 cm x 10 cm located on the right stifle joint, leucocytosis, and anaemia. Radiographic examination of the joint revealed marked soft tissue swelling with amorphous areas of mineralization and complete destruction of the proximal tibia. Smooth and solid periosteal reaction was seen around the tibia and fibula with a Codman’s triangle. Multiple nodules and a mass with soft tissue opacity were seen in the lung fields. Post-mortem examination revealed separation of tibia and fibula, softening of the proximal parts of the tibia, and complete integration of the proximal region of the two bones and articular tissues into the surrounding muscular tissues. Multifocal nodular lesions of variable sizes were mostly found in the lungs and partly in the liver. Histologically, predominantly oval and round cells with variable nuclear sizes and moderate mitoses were observed in tissue samples from the joint, lungs and the liver although some parts of the lung metastases showed both round and spindle shaped tumor cells. Clinical profile is suggestive of aggressive biphasic (spindle and epithelial) type of synovial cell sarcoma with lung and liver metastasis. Early radiographic and biopsy examination of persistent musculoskeletal nodules is recommended for early diagnosis and interventions.


2000 ◽  
Vol 88 (3) ◽  
pp. 1022-1028 ◽  
Author(s):  
Lu Wang ◽  
Kenneth L. Pinder ◽  
Joel L. Bert ◽  
Mitsushi Okazawa ◽  
Peter D. Paré

Folding of the airway mucosal membrane provides a mechanical load that impedes airway smooth muscle contraction. Mechanical testing of rabbit tracheal mucosal membrane showed that the membrane is stiffer in the longitudinal than in the circumferential direction of the airway. To explain this difference in the mechanical properties, we studied the morphological structure of the rabbit tracheal mucosal membrane in both longitudinal and circumferential directions. The collagen fibers were found to form a random meshwork, which would not account for differences in stiffness in the longitudinal and circumferential directions. The volume fraction of the elastic fibers was measured using a point-counting technique. The orientation of the elastic fibers in the tissue samples was measured using a new method based on simple geometry and probability. The results showed that the volume fraction of the elastic fibers in the rabbit tracheal mucosal membrane was ∼5% and that the elastic fibers were mainly oriented in the longitudinal direction. Age had no statistically significant effect on either the volume fraction or the orientation of the elastic fibers. Linear correlations were found between the steady-state stiffness and the quantity of the elastic fibers oriented in the direction of testing.


2021 ◽  
Author(s):  
K Moffitt ◽  
E Cheung ◽  
T Yeung ◽  
C Stamoulis ◽  
R Malley

A comprehensive understanding of how Staphylococcus aureus adapts to cause infections in humans can inform development of diagnostic, therapeutic, and preventive approaches. Expression analysis of clinical strain libraries depicts in vitro conditions that differ from those in human infection, but low bacterial burden and the requirement for reverse transcription or nucleic acid amplification complicate such analyses of bacteria causing human infection. We developed methods to evaluate the mRNA transcript signature of S. aureus in pediatric skin and soft tissue (SSTI) infections directly ex vivo. Abscess drainage from 47 healthy pediatric patients undergoing drainage of a soft tissue infection was collected, and RNA was extracted from samples from patients with microbiologically confirmed S. aureus abscesses (42% due to methicillin-resistant S. aureus, MRSA). Using the Nanostring platform and primers targeting S. aureus mRNA transcripts encoding surface-expressed or secreted proteins, we measured direct counts of 188 S. aureus mRNA transcripts in abscess drainage. We further evaluated this mRNA signature in murine models of S. aureus SSTI and nasal colonization where the kinetics of the transcriptome could be determined. Heat maps of the S. aureus mRNA signatures from pediatric abscesses demonstrated consistent per target expression across patients. While there was significant overlap with the profiles from murine SSTI and nasal colonization, important differences were noted, which can inform efforts to develop therapeutic and vaccine approaches.


2022 ◽  
Author(s):  
Katarína Kacvinská ◽  
Martina Trávničková ◽  
Lucy Vojtová ◽  
Petr Poláček ◽  
Jana Dorazilová ◽  
...  

Abstract This study deals with cellulose derivatives in relation to the collagen fibrils in composite collagen-cellulose scaffolds for soft tissue engineering. Two types of cellulose, i.e., oxidized cellulose (OC) and carboxymethyl cellulose (CMC), were blended with collagen (Col) to enhance its elasticity, stability and sorptive biological properties, e.g. hemostatic and antibacterial features. The addition of OC supported the resistivity of the Col fibrils in a dry environment, while in a moist environment OC caused a radical drop. The addition of CMC reduced the mechanical strength of the Col fibrils in both environments. The elongation of the Col fibrils was increased by both types of cellulose derivatives in both environments, which is closely related to tissue like behaviour. In these various mechanical environments, the ability of human adipose-derived stem cells (hADSCs) to adhere and proliferate was significantly greater in the Col and Col/OC scaffolds than in the Col/CMC scaffold. This is explained by deficient mechanical support and loss of stiffness due to the high swelling capacity of CMC. Although Col/OC and Col/CMC acted differently in terms of mechanical properties, both materials were observed to be cytocompatible, with varying degrees of further support for cell adhesion and proliferation. While Col/OC can serve as a scaffolding material for vascular tissue engineering and for skin tissue engineering, Col/CMC seems to be more suitable for moist wound healing, e.g. as a mucoadhesive gel for exudate removal, since there was almost no cell adhesion.


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