scholarly journals Long-Term Evaluation of Poly(lactic acid) (PLA) Implants in a Horse: An Experimental Pilot Study

Molecules ◽  
2021 ◽  
Vol 26 (23) ◽  
pp. 7224
Author(s):  
Júlia Ribeiro Garcia Carvalho ◽  
Gabriel Conde ◽  
Marina Lansarini Antonioli ◽  
Clarissa Helena Santana ◽  
Thayssa Oliveira Littiere ◽  
...  
Keyword(s):  
Foreign Body Response ◽  
Poly Lactic Acid ◽  
Future Research ◽  
Histopathologic Evaluation ◽  
Term Evaluation ◽  
Mechanical Nociceptive Threshold ◽  
Clinical Changes ◽  
Hematoxylin Eosin ◽  
Body Response

In horses, there is an increasing interest in developing long-lasting drug formulations, with biopolymers as viable carrier alternatives in addition to their use as scaffolds, suture threads, screws, pins, and plates for orthopedic surgeries. This communication focuses on the prolonged biocompatibility and biodegradation of PLA, prepared by hot pressing at 180 °C. Six samples were implanted subcutaneously on the lateral surface of the neck of one horse. The polymers remained implanted for 24 to 57 weeks. Physical examination, plasma fibrinogen, and the mechanical nociceptive threshold (MNT) were performed. After 24, 28, 34, 38, and 57 weeks, the materials were removed for histochemical analysis using hematoxylin-eosin and scanning electron microscopy (SEM). There were no essential clinical changes. MNT decreased after the implantation procedure, returning to normal after 48 h. A foreign body response was observed by histopathologic evaluation up to 38 weeks. At 57 weeks, no polymer or fibrotic capsules were identified. SEM showed surface roughness suggesting a biodegradation process, with an increase in the median pore diameter. As in the histopathological evaluation, it was not possible to detect the polymer 57 weeks after implantation. PLA showed biocompatible degradation and these findings may contribute to future research in the biomedical area.

Long-Term Evaluation of the Poly(Lactic Acid) (PLA) Implants in a Horse: An Experimental Pilot Study

2021 ◽  
Author(s):  
Julia RG Carvalho ◽  
Gabriel Conde ◽  
Marina L Antonioli ◽  
Clarissa H Santana ◽  
Thayssa O Littiere ◽  
...  
Keyword(s):  
Foreign Body Response ◽  
Poly Lactic Acid ◽  
Future Research ◽  
Average Pore ◽  
Biodegradation Process ◽  
Term Evaluation ◽  
Clinical Changes ◽  
Hematoxylin Eosin ◽  
Body Response

In horses, there is an increasing interest in developing long-lasting drug formulations, with bi-opolymers as viable carrier alternatives in addition to their use as scaffolds, suture threads, screws, pins, and plates for orthopedic surgeries. This communication focuses on the prolonged biocompatibility and biodegradation of PLA, prepared by hot pressing at 180 ºC. Six samples were implanted subcutaneously on the lateral surface of the neck of one horse. The polymers remained implanted for 24 to 57 weeks. Physical examination, plasma fibrinogen, and the mechanical noci-ceptive threshold (MNT) were performed. After 24, 28, 34, 38, and 57 weeks, the materials were removed for histochemical analysis using hematoxylin-eosin and scanning electron microscopy (SEM). There were no essential clinical changes. MNT decreased after the implantation procedure, returning to normal after 48h. A foreign body response was observed by histopathologic evalua-tion up to 38 weeks. At 57 weeks, no polymer or fibrotic capsules were identified. SEM showed surface roughness suggesting a biodegradation process, with an increase in the average pore di-ameter. As in the histopathological evaluation, it was not possible to detect the polymer 57 weeks after implantation. PLA showed biocompatible degradation and these findings may contribute to future research in the biomedical area.

Long-term evaluation of adhesion formation and foreign body response to three new meshes

2014 ◽  
Vol 29 (8) ◽  
pp. 2251-2259 ◽  
Author(s):  
R. R. M. Vogels ◽  
K. W. Y. van Barneveld ◽  
J. W. A. M. Bosmans ◽  
G. Beets ◽  
M. J. J. Gijbels ◽  
...  
Keyword(s):  
Foreign Body ◽  
Adhesion Formation ◽  
Foreign Body Response ◽  
Term Evaluation ◽  
Body Response

Examinations of a new long-term degradable electrospun polycaprolactone scaffold in three rat abdominal wall models

2017 ◽  
Vol 31 (7) ◽  
pp. 1077-1086 ◽  
Author(s):  
Hanna Jangö ◽  
Søren Gräs ◽  
Lise Christensen ◽  
Gunnar Lose
Keyword(s):  
Pelvic Organ Prolapse ◽  
Foreign Body ◽  
Abdominal Wall ◽  
Muscle Fiber ◽  
Pelvic Organ ◽  
Foreign Body Response ◽  
Heavy Load ◽  
Tissue Construct ◽  
Body Response

Alternative approaches to reinforce native tissue in reconstructive surgery for pelvic organ prolapse are warranted. Tissue engineering combines the use of a scaffold with the regenerative potential of stem cells and is a promising new concept in urogynecology. Our objective was to evaluate whether a newly developed long-term degradable polycaprolactone scaffold could provide biomechanical reinforcement and function as a scaffold for autologous muscle fiber fragments. We performed a study with three different rat abdominal wall models where the scaffold with or without muscle fiber fragments was placed (1) subcutaneously (minimal load), (2) in a partial defect (partial load), and (3) in a full-thickness defect (heavy load). After 8 weeks, no animals had developed hernia, and the scaffold provided biomechanical reinforcement, even in the models where it was subjected to heavy load. The scaffold was not yet degraded but showed increased thickness in all groups. Histologically, we found a massive foreign body response with numerous large giant cells intermingled with the fibers of the scaffold. Cells from added muscle fiber fragments could not be traced by PKH26 fluorescence or desmin staining. Taken together, the long-term degradable polycaprolactone scaffold provided biomechanical reinforcement by inducing a marked foreign-body response and attracting numerous inflammatory cells to form a strong neo-tissue construct. However, cells from the muscle fiber fragments did not survive in this milieu. Properties of the new neo-tissue construct must be evaluated at the time of full degradation of the scaffold before its possible clinical value in pelvic organ prolapse surgery can be evaluated.

Long-term pericardial catheterization is associated with minimum foreign-body response

2007 ◽  
Vol 70 (2) ◽  
pp. 221-227 ◽  
Author(s):  
Carlo R. Bartoli ◽  
Ichiro Akiyama ◽  
John J. Godleski ◽  
Richard L. Verrier
Keyword(s):  
Foreign Body ◽  
Foreign Body Response ◽  
Body Response

scholarly journals Adaptive and multifunctional hydrogel hybrid probes for long-term sensing and modulation of neural activity

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Seongjun Park ◽  
Hyunwoo Yuk ◽  
Ruike Zhao ◽  
Yeong Shin Yim ◽  
Eyob W. Woldeghebriel ◽  
...  
Keyword(s):  
Foreign Body ◽  
Brain Regions ◽  
Foreign Body Response ◽  
Behavioral Studies ◽  
Hydrogel Matrix ◽  
Underlying Mechanisms ◽  
Hybrid Devices ◽  
The Brain ◽  
Body Response

AbstractTo understand the underlying mechanisms of progressive neurophysiological phenomena, neural interfaces should interact bi-directionally with brain circuits over extended periods of time. However, such interfaces remain limited by the foreign body response that stems from the chemo-mechanical mismatch between the probes and the neural tissues. To address this challenge, we developed a multifunctional sensing and actuation platform consisting of multimaterial fibers intimately integrated within a soft hydrogel matrix mimicking the brain tissue. These hybrid devices possess adaptive bending stiffness determined by the hydration states of the hydrogel matrix. This enables their direct insertion into the deep brain regions, while minimizing tissue damage associated with the brain micromotion after implantation. The hydrogel hybrid devices permit electrophysiological, optogenetic, and behavioral studies of neural circuits with minimal foreign body responses and tracking of stable isolated single neuron potentials in freely moving mice over 6 months following implantation.

scholarly journals Mechanically Matched Silicone Brain Implants Reduce Brain Foreign Body Response

2020 ◽  
Author(s):  
Edward Zhang ◽  
Alia Alameri ◽  
Jean-Pierre Clement ◽  
Andy Ng ◽  
Timothy E Kennedy ◽  
...  
Keyword(s):  
Foreign Body ◽  
Neurological Disorders ◽  
Foreign Body Response ◽  
Brain Implants ◽  
Rat Neocortex ◽  
The Brain ◽  
Post Implantation ◽  
Body Response ◽  
Clinical Adoption

Brain implants are increasingly used to treat neurological disorders and diseases. However, the brain foreign body response (FBR) elicited by implants affects neuro-electrical transduction and long-term reliability limiting their clinical adoption. The mismatch in Young's modulus between silicon implants (~180 GPa) and brain tissue (~1-30 kPa) exacerbates the FBR resulting in the development of flexible implants from polymers such as polyimide (~1.5-2.5 GPa). However, a stiffness mismatch of at least two orders of magnitude remains. Here, we introduce (i) the first mechanically matched brain implant (MMBI) made from silicone (~20 kPa), (ii) new microfabrication methods, and (iii) a novel dissolvable sugar shuttle to reliably implant MMBIs. MMBIs were fabricated via vacuum-assisted molding using sacrificial sugar molds and were then encased in sugar shuttles that dissolved within 2 min after insertion into rat brains. Sections of rat neocortex implanted with MMBIs, PDMS implants, and silicon implants were analyzed by immunohistochemistry 3 and 9-weeks post-implantation. MMBIs resulted in significantly higher neuronal density and lower FBR within 50 μm of the tissue-implant interface compared to PDMS and silicon implants suggesting that materials mechanically matched to brain further minimize the FBR and could contribute to better implant functionality and long-term reliability.

scholarly journals Mechanical Flexibility Reduces the Foreign Body Response to Long-Term Implanted Microelectrodes in Rabbit Cortex

PLoS ONE ◽  
2016 ◽  
Vol 11 (10) ◽  
pp. e0165606 ◽  
Author(s):  
Harbaljit S. Sohal ◽  
Gavin J. Clowry ◽  
Andrew Jackson ◽  
Anthony O’Neill ◽  
Stuart N. Baker
Keyword(s):  
Foreign Body ◽  
Foreign Body Response ◽  
Body Response

scholarly journals Unions and equality: 50 years on from the fight for fair pay at Dagenham

2019 ◽  
Vol 41 (2) ◽  
pp. 344-356 ◽  
Author(s):  
Gill Kirton
Keyword(s):  
Design Methodology ◽  
Historical Background ◽  
Future Research ◽  
National Union ◽  
Content Type ◽  
Original Analysis ◽  
Term Evaluation ◽  
Current Record ◽  
Practical Implications

PurposeThe purpose of this paper is to review historical and contemporary union driven advances in gender and race equality within the movement and the workplace in order to show how far unions have come in the last 50 years, but also to identify continuing equality deficits.Design/methodology/approachAs well as reviewing extant literature in order to provide historical background, the paper draws upon original analysis of the series of biennial TUC Equality Audits, the latest SERTUC equality survey and interviews with national union officers responsible for equality in large-, medium- and small-sized unions.FindingsOver the last 50 years, unions have made considerable progress in representing women both in leadership and democratic structures as well as in the workplace bargaining and consultative arena. However, BAME members remain underrepresented in both domains. A hostile socio-economic/political context threatens to hinder further progress.Research limitations/implicationsIt is quite clear that the authors cannot assess unions’ current record on equality by reference only to outcomes and benefits of big set-piece organisation, industry or sector negotiations. Future research could usefully explore in more depth unions’ qualitative contribution to workplace equality practices in context of challenges in the internal and external environments.Practical implicationsUnions need to step up commitment to integrating equality into the bargaining agenda. They also need to continue investing in campaigning activities and identify ways of making successful outcomes more visible within the union, to members and to non-unionised workers. Workplace unions need to develop strategies to confront the fact that strong equality policies do not necessarily translate into good workplace practices.Originality/valueThe paper provides a long-term evaluation of union progress on equality within the movement itself and the workplace.

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