scholarly journals In vivo soft tissue reinforcement with bacterial nanocellulose

2021 ◽  
Author(s):  
Irene Anton-Sales ◽  
Soledad Roig-Sanchez ◽  
Kamelia Anna Traeger ◽  
Christine Weis ◽  
Anna Laromaine ◽  
...  

The use of surgical meshes to reinforce damaged internal soft tissues has been instrumental for successful hernia surgery; a highly prevalent condition affecting yearly more than 20 million patients worldwide....

Author(s):  
Ming Jia ◽  
Jean W. Zu ◽  
Alireza Hariri

Knowledge of tissue mechanical properties is widely required by medical applications, such as disease diagnostics, surgery operation, simulation, planning, and training. A new portable device, called Tissue Resonator Indenter Device (TRID), has been developed for measurement of regional viscoelastic properties of soft tissues at the Bio-instrument and Biomechanics Lab of the University of Toronto. As a device for soft tissue properties in-vivo measurements, the reliability of TRID is crucial. This paper presents TRID’s working principle and the experimental study of TRID’s reliability with respect to inter-reliability, intra-reliability, and the indenter misalignment effect as well. The experimental results show that TRID is a reliable device for in-vivo measurements of soft tissue mechanical properties.


Author(s):  
Massoud Akbarshahi ◽  
Justin W. Fernandez ◽  
Anthony Schache ◽  
Richard Baker ◽  
Marcus G. Pandy

The ability to accurately measure joint kinematics in vivo is of critical importance to researchers in the field of biomechanics [1]. Applications range from the quantitative evaluation of different surgical techniques, treatment methods and/or implant designs, to the development of computer-based models capable of simulating normal and pathological musculoskeletal conditions [1,2]. Currently, non-invasive marker-based three dimensional (3D) motion analysis is the most commonly used method for quantitative assessment of normal and pathological locomotion. The accuracy of this technique is influenced by movement of the soft tissues relative to the underlying bones, which causes inaccuracies in the determination of segmental anatomical coordinate systems and tracking of segmental motion. The purpose of this study was to quantify the errors in the measurement of knee-joint kinematics due solely to soft-tissue artifact (STA) in healthy subjects. To facilitate valid inter-subject comparisons of the kinematic data, relevant anatomical coordinate systems were defined using 3D bone models generated from magnetic resonance imaging (MRI).


2000 ◽  
Vol 44 (10) ◽  
pp. 2728-2732 ◽  
Author(s):  
Martin Frossard ◽  
Christian Joukhadar ◽  
Boban M. Erovic ◽  
Peter Dittrich ◽  
Paulus E. Mrass ◽  
...  

ABSTRACT Fosfomycin is a broad-spectrum antibiotic which is established as therapy for uncomplicated lower urinary tract infections. In addition, preliminary data indicate that fosfomycin has a potential role in the treatment of soft tissue infections. However, the use of fosfomycin has not been established for this condition, and it is unclear whether the level of fosfomycin penetration into human soft tissues is high enough to eradicate relevant pathogens. To better characterize the antibiotic potential of fosfomycin, we applied a combined in vivo pharmacokinetic-in vitro pharmacodynamic model to human volunteers. For this purpose fosfomycin concentrations in vivo in the fluid of the interstitial space of human soft tissues were measured by microdialysis following intravenous infusion of 4 or 8 g of fosfomycin (n = 6). Subsequently, bacterial isolates with relevance for soft tissue infections were exposed to concentrations according to the in vivo pharmacokinetic profile in the interstitial space fluid obtained by microdialysis. Our experiments indicated a high degree of soft tissue penetration for fosfomycin, with ratios of the area under the concentration-time curve from 0 to 8 h for muscle (AUC0–8muscle )/AUC0–8serum of 0.48 ± 0.08 and 0.53 ± 0.04 and ratios of AUC0–8adipose tissue /AUC0–8serum of 0.74 ± 0.12 and 0.71 ± 0.11 following administration of 4 and 8 g, respectively. In corresponding in vitro simulation experiments with selected isolates of Staphylococcus aureus,Enterobacter cloacae, and Serratia marcescensfor which MICs were 16 μg/ml, organisms were undetectable after a single dosing interval. Fosfomycin exhibits a strong ability to penetrate into the fluid of the interstitial space of soft tissues and reaches levels sufficient to substantially inhibit the growth of relevant bacteria at the target site. We therefore conclude that fosfomycin might qualify as an alternative candidate for the therapy of soft tissue infections.


2004 ◽  
Vol 48 (11) ◽  
pp. 4246-4249 ◽  
Author(s):  
Florian Islinger ◽  
Rene Bouw ◽  
Mathias Stahl ◽  
Edith Lackner ◽  
Petra Zeleny ◽  
...  

ABSTRACT Free gemifloxacin concentrations in the interstitial space fluid of skeletal muscle and subcutaneous adipose tissue were measured by means of in vivo microdialysis to characterize the ability of gemifloxacin to penetrate human soft tissues. Twelve healthy volunteers received a single oral dose of 320 mg of gemifloxacin. The mean areas under the concentration-time curves from 0 to 10 h (AUC0-10) were significantly higher for soft tissue than for unbound gemifloxacin in plasma (P < 0.05). The ratios of the mean AUC0-10 for tissue to the AUC0-10 for free gemifloxacin in plasma were 1.7 ± 0.7 (mean ± standard deviation) for skeletal muscle and 2.4 ± 1.0 for adipose tissue. The AUC0-24 ratios for free gemifloxacin in tissues to the MIC at which 90% of frequently isolated bacteria are inhibited were close to or higher than 100 h. Therefore, based on pharmacokinetic and pharmacodynamic calculations, we conclude that gemifloxacin might be a useful therapeutic option for the treatment of soft tissue infections.


2005 ◽  
Vol 49 (10) ◽  
pp. 4368-4371 ◽  
Author(s):  
F. J. Legat ◽  
R. Krause ◽  
P. Zenahlik ◽  
C. Hoffmann ◽  
S. Scholz ◽  
...  

ABSTRACT We investigated the pharmacokinetics of piperacillin and tazobactam in the extracellular space fluid of inflamed soft tissues of six patients with diabetic foot infection using in vivo microdialysis and found similar penetration for piperacillin but not for tazobactam into inflamed and noninflamed soft tissue.


2008 ◽  
Vol 52 (11) ◽  
pp. 3941-3946 ◽  
Author(s):  
Aryun Kim ◽  
Larry A. Suecof ◽  
Christina A. Sutherland ◽  
Lihong Gao ◽  
Joseph L. Kuti ◽  
...  

ABSTRACT Daptomycin is approved for the treatment of complicated skin and soft tissue infections, including diabetic wounds of the lower extremities, at a dose of 4 mg/kg of body weight once daily. For such localized tissue infections, drug concentrations in the interstitial space are an important determinant of successful therapy. In the diabetic population, peripheral arterial disease may limit antibiotic penetration into the target tissue. The objective of this study was to describe and compare the pharmacokinetic profiles of daptomycin in the interstitial fluid of soft tissues in diabetic and healthy volunteers by using in vivo microdialysis. Twelve subjects (six diabetic and six healthy) received a single 4-mg/kg dose of daptomycin intravenously. Samples of plasma and tissue were simultaneously collected over 24 h. Diabetic and healthy groups were matched in mean age (±10 years), gender ratio, mean weight (±10 kg), and creatinine clearance rate (±20 ml/min/1.73 m2). Pharmacokinetic parameters for plasma were similar between groups (P > 0.05). The mean peak drug concentrations ± standard deviations in tissue were 4.3 ± 3.3 μg/ml and 3.8 ± 1.4 μg/ml for diabetic and healthy subjects, respectively. The degree of tissue penetration, defined as the ratio of the area under the free drug concentration-time curve for tissue to that for plasma, was 0.93 ± 0.61 for diabetic subjects and 0.74 ± 0.09 for healthy subjects (P = 0.46). Daptomycin at 4 mg/kg penetrated well into the soft tissue, reaching concentrations approximately 70 to 90% of those of the free drug in plasma. Moreover, these free, bioactive concentrations in tissue exceeded the MICs for staphylococci and streptococci over the 24-h dosing interval.


2021 ◽  
Author(s):  
Min Wang ◽  
Shuang Zhang ◽  
Longjie Chen ◽  
Haixiao Zou ◽  
Yining Wang ◽  
...  

Abstract Background: This study aimed to investigate clinical characteristics and early soft tissues response to zirconium oxide (Zr) and titanium (Ti) abutments in dogs. Methods: Eight implants-four at each hemi-mandible were inserted after bilateral mandibular third and fourth premolars and first molars extraction. Two Zr and two Ti healing abutments were connected in each unilateral mandible 8 weeks later. The ligation method was used to make peri-implant mucositis model. The twenty-four abutments were divided into four groups, Zr and Ti healing abutments with ligation (ZrL, TiL) and non-ligation (ZrN, TiN) groups. Clinical index, peri-implant crevicular fluid (PICF) and inflammatory cytokines (TNF-α and IL-1β), soft tissue responses were tested. Two-way analysis of variance was used to analyze the data. Results: The results showed that the clinical index were similar around Zr and Ti healing abutments. PICF in ZrL and TiL groups were significantly higher than those in ZrN and TiN groups. Immunohistochemistry demonstrated inflammatory cells were non-significant differences. Conclusion: These data indicate soft tissue responses to Zr healing abutments with peri-implant mucositis was comparable to those to Ti healing abutments in vivo, and can provide theoretical foundation for Zr’s clinical application.


2021 ◽  
Author(s):  
Panagiotis Chatzistergos ◽  
Nachiappan Chockalingam

Abstract This proof-of-concept study demonstrates that repetitive loading to the pain threshold can safely recreate overloading-induced soft tissue damage and that localised tissue stiffening can be used as a marker for injury. This concept was demonstrated here for the soft tissue of the sole of the foot where it was found that repeated loading to the pain threshold led to long-lasting statistically significant stiffening in the areas where pressure was most intense. Loading at lower magnitudes did not have the same effect. This method can shed new light on the aetiology of overloading injury in the foot to improve the management of conditions such as diabetic foot ulceration and heel pain syndrome. At the same time, the presented concept can also enable the direct assessment of subject-specific thresholds for overloading in other soft tissues which are sensitive to pain, accessible for imaging and can be loaded in a clinically relevant manner.


Author(s):  
Mohammad F. Hadi ◽  
Fabien J. Delalondre ◽  
Cameron W. Smith ◽  
Lijuan Zhang ◽  
Mark S. Shephard ◽  
...  

Indentation has become a popular research technique for the mechanical characterization of collagen-based soft tissues. The popularity of the method stems from its requirement of a modestly sized sample, from its ability to be applied in vitro as well as in vivo, and from the ready availability of instrumentation and analytical techniques borrowed from a long tradition of its application to non-biological materials. Many analytical models for the indentation of collagen-based soft tissues rely on a Hertzian contact model. Such a model emphasizes the contributions of an idealized material in compression over the contributions of the material in tension. However, this approach largely neglects the role of the collagen microstructure in soft tissue that has the capacity to carry far greater mechanical loads in tension rather than in compression.


mSphere ◽  
2019 ◽  
Vol 4 (5) ◽  
Author(s):  
Hema Sharma ◽  
Claire E. Turner ◽  
Matthew K. Siggins ◽  
Mona El-Bahrawy ◽  
Bruno Pichon ◽  
...  

ABSTRACT Nonmenstrual toxic shock syndrome (nmTSS), linked to TSST-1-producing CC30 Staphylococcus aureus, is the leading manifestation of toxic shock syndrome (TSS). Due to case rarity and a lack of tractable animal models, TSS pathogenesis is poorly understood. We developed an S. aureus abscess model in HLA class II transgenic mice to investigate pathogenesis and treatment. TSST-1 sensitivity was established using murine spleen cell proliferation assays and cytokine assays following TSST-1 injection in vivo. HLA-DQ8 mice were infected subcutaneously with a tst-positive CC30 methicillin-sensitive S. aureus clinical TSS-associated isolate. Mice received intraperitoneal flucloxacillin, clindamycin, flucloxacillin and clindamycin, or a control reagent. Abscess size, bacterial counts, TSST-1 expression, and TSST-1 bioactivity were measured in tissues. Antibiotic effects were compared with the effects of control reagent. Purified TSST-1 expanded HLA-DQ8 T-cell Vβ subsets 3 and 13 in vitro and instigated cytokine release in vivo, confirming TSST-1 sensitivity. TSST-1 was detected in abscesses (0 to 8.0 μg/ml) and draining lymph nodes (0 to 0.2 μg/ml) of infected mice. Interleukin 6 (IL-6), gamma interferon (IFN-γ), KC (CXCL1), and MCP-1 were consistent markers of inflammation during infection. Clindamycin-containing antibiotic regimens reduced abscess size and TSST-1 production. Infection led to detectable TSST-1 in soft tissues, and TSST-1 was detected in draining lymph nodes, events which may be pivotal to TSS pathogenesis. The reduction in TSST-1 production and lesion size after a single dose of clindamycin underscores a potential role for adjunctive clindamycin at the start of treatment of patients suspected of having TSS to alter disease progression. IMPORTANCE Staphylococcal toxic shock syndrome (TSS) is a life-threatening illness causing fever, rash, and shock, attributed to toxins produced by the bacterium Staphylococcus aureus, mainly toxic shock syndrome toxin 1 (TSST-1). TSS was in the past commonly linked with menstruation and high-absorbency tampons; now, TSS is more frequently triggered by other staphylococcal infections, particularly of skin and soft tissue. Investigating the progress and treatment of TSS in patients is challenging, as TSS is rare; animal models do not mimic TSS adequately, as toxins interact best with human immune cells. We developed a new model of staphylococcal soft tissue infection in mice producing human immune cell proteins, rendering them TSST-1 sensitive, to investigate TSS. The significance of our research was that TSST-1 was found in soft tissues and immune organs of mice and that early treatment of mice with the antibiotic clindamycin altered TSST-1 production. Therefore, the early treatment of patients suspected of having TSS with clindamycin may influence their response to treatment.


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