Regenerable smart antibacterial surfaces: full removal of killed bacteria via a sequential degradable layer

2018 ◽  
Vol 6 (23) ◽  
pp. 3946-3955 ◽  
Author(s):  
Yangcui Qu ◽  
Ting Wei ◽  
Jian Zhao ◽  
Shuaibing Jiang ◽  
Peng Yang ◽  
...  
Keyword(s):  
Bactericidal Activity ◽  
Hybrid Film ◽  
Antibacterial Surfaces

An antibiotic-free and regenerable antibacterial hybrid film with both photothermal bactericidal activity and bacteria-releasing properties is fabricated on diverse substrates.

scholarly journals Model-Driven Controlled Alteration of Nanopillar Cap Architecture Reveals its Effects on Bactericidal Activity

2020 ◽  
Vol 8 (2) ◽  
pp. 186 ◽  
Author(s):  
Taiyeb Zahir ◽  
Jiri Pesek ◽  
Sabine Franke ◽  
Jasper Van Pee ◽  
Ashish Rathore ◽  
...  
Keyword(s):  
Bactericidal Activity ◽  
Cell Envelope ◽  
Antibacterial Properties ◽  
Biophysical Model ◽  
Surface Measurement ◽  
Dependent Manner ◽  
Bending Rigidity ◽  
Nanostructured Surfaces ◽  
Model Driven ◽  
Antibacterial Surfaces

Nanostructured surfaces can be engineered to kill bacteria in a contact-dependent manner. The study of bacterial interactions with a nanoscale topology is thus crucial to developing antibacterial surfaces. Here, a systematic study of the effects of nanoscale topology on bactericidal activity is presented. We describe the antibacterial properties of highly ordered and uniformly arrayed cotton swab-shaped (or mushroom-shaped) nanopillars. These nanostructured surfaces show bactericidal activity against Staphylococcus aureus and Pseudomonas aeruginosa. A biophysical model of the cell envelope in contact with the surface, developed ab initio from the infinitesimal strain theory, suggests that bacterial adhesion and subsequent lysis are highly influenced by the bending rigidity of the cell envelope and the surface topography formed by the nanopillars. We used the biophysical model to analyse the influence of the nanopillar cap geometry on the bactericidal activity and made several geometrical alterations of the nanostructured surface. Measurement of the bactericidal activities of these surfaces confirms model predictions, highlights the non-trivial role of cell envelope bending rigidity, and sheds light on the effects of nanopillar cap architecture on the interactions with the bacterial envelope. More importantly, our results show that the surface nanotopology can be rationally designed to enhance the bactericidal efficiency.

scholarly journals The multi-faceted mechano-bactericidal mechanism of nanostructured surfaces

2020 ◽  
Vol 117 (23) ◽  
pp. 12598-12605 ◽  
Author(s):  
Elena P. Ivanova ◽  
Denver P. Linklater ◽  
Marco Werner ◽  
Vladimir A. Baulin ◽  
XiuMei Xu ◽  
...  
Keyword(s):  
Cell Death ◽  
Bactericidal Activity ◽  
Mechanical Energy ◽  
Bactericidal Effect ◽  
Bacterial Cells ◽  
Gram Stain ◽  
Nanostructured Surfaces ◽  
Bacterial Cell Death ◽  
Antibacterial Surfaces ◽  
Nanopillar Arrays

The mechano-bactericidal activity of nanostructured surfaces has become the focus of intensive research toward the development of a new generation of antibacterial surfaces, particularly in the current era of emerging antibiotic resistance. This work demonstrates the effects of an incremental increase of nanopillar height on nanostructure-induced bacterial cell death. We propose that the mechanical lysis of bacterial cells can be influenced by the degree of elasticity and clustering of highly ordered silicon nanopillar arrays. Herein, silicon nanopillar arrays with diameter 35 nm, periodicity 90 nm and increasing heights of 220, 360, and 420 nm were fabricated using deep UV immersion lithography. Nanoarrays of 360-nm-height pillars exhibited the highest degree of bactericidal activity toward both Gram stain-negativePseudomonas aeruginosaand Gram stain-positiveStaphylococcus aureusbacteria, inducing 95 ± 5% and 83 ± 12% cell death, respectively. At heights of 360 nm, increased nanopillar elasticity contributes to the onset of pillar deformation in response to bacterial adhesion to the surface. Theoretical analyses of pillar elasticity confirm that deflection, deformation force, and mechanical energies are more significant for the substrata possessing more flexible pillars. Increased storage and release of mechanical energy may explain the enhanced bactericidal action of these nanopillar arrays toward bacterial cells contacting the surface; however, with further increase of nanopillar height (420 nm), the forces (and tensions) can be partially compensated by irreversible interpillar adhesion that reduces their bactericidal effect. These findings can be used to inform the design of next-generation mechano-responsive surfaces with tuneable bactericidal characteristics for antimicrobial surface technologies.

2-amino-5-(4-chloro-1h-imidazol-5-yl)-1,3,4-thiadiazoles: synthesis, pyrimidoannulation and the bactericidal activity

2013 ◽  
Vol 11 (4(44)) ◽  
pp. 22-27
Author(s):  
A. M. Grozav ◽  
V. O. Chornous ◽  
O. I. Gavrylyuk ◽  
M. V. Vovk
Keyword(s):  
Bactericidal Activity

TO STUDY THE DYNAMICS OF IMMUNITY IN BLACK-AND-WHITE COWS DEPENDING ON AGE

2020 ◽  
pp. 49-52
Author(s):  
М.В. ДОВЫДЕНКОВА
Keyword(s):  
Bactericidal Activity ◽  
Phagocytic Activity ◽  
Physiological State ◽  
Age Groups ◽  
Statistical Processing ◽  
Natural Resistance ◽  
Black And White ◽  
Feeding Methods ◽  
High Degree ◽  
The Relationship

Проведена статистическая обработка сформированной базы данных показателей неспецифической резистентности MS «Excel» с целью изучения динамики иммунитета по параметрам бактерицидной, лизоцимной и фагоцитарной активности у крупного рогатого скота черно-пестрой породы разных возрастов. Было установлено, что средние значения показателей лизоцимной и бактерицидной активности у телят в 6 мес были ниже (47,89% и 49,09%, соответственно), чем у животных в 3—4 года (53,75% и 52,81%). Выведено уравнение регрессии, описывающее взаимосвязь между средними показателями фагоцитарной активности и возрастом при высокой степени достоверности (R2=0,90). Изменения лизоцимной и бактерицидной активности в зависимости от возраста были недостоверными (R2=0,58 и R2=0,49, соответственно). Установлена высокая корреляция между бактерицидной и лизоцимной активностью. Отмечена динамика изменения неспецифического иммунитета у коров различных возрастных групп. Создание баз данных и постоянный мониторинг основных показателей естественной резистентности в зависимости от различных факторов (породы, возраста, стадий лактации, кормления, способов содержания), которые влияют на данные показатели, необходимо для оценки физиологического состояния организма животных и их устойчивости к болезням. Statistical processing of the generated MS "Excel" on indicators of non-specific resistance database was carried out with the aim of studying the dynamics of the development of immunity in terms of bactericidal, lysozyme and phagocytic activity in black-and-white cattle of different ages. It was found that the average values of indicators of lysozyme and bactericidal activity in calves at 6 months were lower (47.89% and 49.09%, respectively) than in animals at the age of 3—4 years (53.75% and 52.81%). The equation of regression was derived, it describes the relationship between the average indicators of phagocytic activity and the age with a high degree of reliability (R2=0.90). The changes in lysozyme and bactericidal activity depending on age were dubious (R2=0.58 and R2=0.49, respectively). The high correlation between bactericidal and lysozyme activity was established. It was noticed that the cows of different age groups experienced the dynamics of changes in nonspecific immunity. The creation of databases and constant monitoring of the main indicators of natural resistance, depending on various factors (breed, age, stages of lactation, feeding, methods of keeping) that affect these indicators, is necessary for assessing the physiological state of the animals’ body of and their resistance to diseases.

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