scholarly journals Bioactive Functional Nanolayers of Chitosan–Lysine Surfactant with Single- and Mixed-Protein-Repellent and Antibiofilm Properties for Medical Implants

Author(s):  
Urban Ajdnik ◽  
Lidija Fras Zemljič ◽  
Olivija Plohl ◽  
Lourdes Pérez ◽  
Janja Trček ◽  
...  
Author(s):  
Anton Lodder ◽  
Markad Kamath ◽  
Adrian R. Upton ◽  
David Armstrong

2020 ◽  
Vol 16 ◽  
Author(s):  
Ramazan Akçan ◽  
Halit Canberk Aydogan ◽  
Mahmut Şerif Yıldırım ◽  
Burak Taştekin ◽  
Necdet Sağlam

Background/aim: Use of nanomaterials in the healthcare applications increases in parallel to technological developments. It is frequently utilized in diagnostic procedures, medications and in therapeutic implementations. Nanomaterials take place among key components of medical implants, which might be responsible for certain toxic effects on human health at nano-level. In this review, nanotoxicological effects, toxicity determination of nanobiomaterials used in human body and their effects on human health are discussed. Material and Method: A detailed review of related literature was performed and evaluated as per nanomaterials and medical implants. Results and Conclusion: The nanotoxic effects of the materials applied to human body and the determination of its toxicity are important. Determination of toxicity for each nanomaterial requires a detailed and multifactorial assessment considering the properties of these materials. There are limited studies in the literature regarding the toxic effects of nanomaterials used in medical implants. Although these implants are potentially biocompatible and biodegradable, it is highly important to discuss nanotoxicological characteristics of medical implant.


2021 ◽  
pp. 1-12
Author(s):  
Olivia T. Cheng ◽  
Andrew P. Stein ◽  
Eric Babajanian ◽  
Kathryn R. Hoppe ◽  
Shawn Li ◽  
...  

BACKGROUND: Implantable medical devices and hardware are prolific in medicine, but hardware associated infections remain a major issue. OBJECTIVE: To develop and evaluate a novel, biologic antimicrobial coating for medical implants. METHODS: Electrochemically compacted collagen sheets with and without crosslinked heparin were synthesized per protocol developed by our group. Sheets were incubated in antibiotic solution (gentamicin or moxifloxacin) overnight, and in vitro activity was assessed with five-day diffusion assays against Pseudomonas aeruginosa. Antibiotic release overtime from gentamicin infused sheets was determined using in vitro elution and high performance liquid chromatography (HPLC). RESULTS: Collagen-heparin-antibiotic sheets demonstrated larger growth inhibition zones against P. aeruginosa compared to collagen-antibiotic alone sheets. This activity persisted for five days and was not impacted by rinsing sheets prior to evaluation. Rinsed collagen-antibiotic sheets did not show any inhibition zones. Elution of gentamicin from collagen-heparin-gentamicin sheets was slow and remained above the minimal inhibitory concentration for gentamicin sensitive organisms for 29 days. Conversely, collagen-gentamicin sheets eluted their antibiotic payload within 24 hours. Overall, heparin associated sheets demonstrated larger inhibition zones against P. aeruginosa and prolonged elution profile via HPLC. CONCLUSION: We developed a novel, local antibiotic delivery system that could be used to coat medical implants/hardware in the future and reduce post-operative infections.


Sensors ◽  
2021 ◽  
Vol 21 (2) ◽  
pp. 421
Author(s):  
Jorge Oevermann ◽  
Peter Weber ◽  
Steffen H. Tretbar

The aim of this work was to extend conventional medical implants by the possibility of communication between them. For reasons of data security and transmitting distances, this communication should be realized using ultrasound, which is generated and detected by capacitive micromachined ultrasonic transducers (CMUTs). These offer the advantage of an inherent high bandwidth and a high integration capability. To protect the surrounding tissue, it has to be encapsulated. In contrast to previous results of other research groups dealing with the encapsulation of CMUTs, the goal here is to integrate the CMUT into the housing of a medical implant. In this work, CMUTs were designed and fabricated for a center frequency of 2 MHz in water and experimentally tested on their characteristics for operation behind layers of Polyether ether ketone (PEEK) and titanium, two typical materials for the housings of medical implants. It could be shown that with silicone as a coupling layer it is possible to operate a CMUT behind the housing of an implant. Although it changes the characteristics of the CMUT, the setup is found to be well suited for communication between two transducers over a distance of at least 8 cm.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Netanel Biton ◽  
Judy Kupferman ◽  
Shlomi Arnon

AbstractA major challenge in use of the optical spectrum for communication and imaging applications is the scattering of light as it passes through diffuse media. Recent studies indicate that light beams with orbital angular momentum (OAM) can penetrate deeper through diffuse media than simple Gaussian beams. To the best knowledge of the authors, in this paper we describe for the first time an experiment examining transmission of OAM beams through biological tissue with thickness of up to a few centimeters, and for OAM modes reaching up to 20. Our results indicate that OAM beams do indeed show a higher transmittance relative to Gaussian beams, and that the greater the OAM, the higher the transmittance also up to 20, Our results extend measured results to highly multi scattering media and indicate that at 2.6 cm tissue thickness for OAM of order 20, we measure nearly 30% more power in comparison to a Gaussian beam. In addition, we develop a mathematical model describing the improved permeability. This work shows that OAM beams can be a valuable contribution to optical wireless communication (OWC) for medical implants, optical biological imaging, as well as recent innovative applications of medical diagnosis.


Author(s):  
Felix Stieglmeier ◽  
Maximilian Grab ◽  
Fabian König ◽  
Joscha Büch ◽  
Christian Hagl ◽  
...  

Author(s):  
Peter R. S. Stijnman ◽  
M. Arcan Erturk ◽  
Cornelis A. T. den Berg ◽  
Alexander J. E. Raaijmakers

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Béatrice S.-Y. Choi ◽  
Noëmie Daniel ◽  
Vanessa P. Houde ◽  
Adia Ouellette ◽  
Bruno Marcotte ◽  
...  

AbstractAnimal models of human diseases are classically fed purified diets that contain casein as the unique protein source. We show that provision of a mixed protein source mirroring that found in the western diet exacerbates diet-induced obesity and insulin resistance by potentiating hepatic mTORC1/S6K1 signaling as compared to casein alone. These effects involve alterations in gut microbiota as shown by fecal microbiota transplantation studies. The detrimental impact of the mixed protein source is also linked with early changes in microbial production of branched-chain fatty acids (BCFA) and elevated plasma and hepatic acylcarnitines, indicative of aberrant mitochondrial fatty acid oxidation. We further show that the BCFA, isobutyric and isovaleric acid, increase glucose production and activate mTORC1/S6K1 in hepatocytes. Our findings demonstrate that alteration of dietary protein source exerts a rapid and robust impact on gut microbiota and BCFA with significant consequences for the development of obesity and insulin resistance.


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