In vitro biocompatiblity of modified polycarbonate as a biomaterial

Microfabricated polymer-metal biosensors for multifarious data collection from electrogenic cellular models

Benchtop tissue cultures have become increasingly complex in recent years, as more on-a-chip biological technologies, such as microphysiological systems (MPS), are developed to incorporate cellular constructs that more accurately represent their respective biological systems. Such MPS have begun facilitating major breakthroughs in biological research and are poised to shape the field in the coming decades. These biological systems require integrated sensing modalities to procure complex, multiplexed datasets with unprecedented combinatorial biological detail. In this work, we expanded upon our polymer-metal biosensor approach by demonstrating a facile technology for compound biosensing that was characterized through custom modeling approaches. As reported herein, we developed a compound chip with 3D microelectrodes, 3D microfluidics, interdigitated electrodes (IDEs) and a microheater. The chip was subsequently tested using the electrical/electrochemical characterization of 3D microelectrodes with 1 kHz impedance and phase recordings and IDE-based high-frequency (~1 MHz frequencies) impedimetric analysis of differential localized temperature recordings, both of which were modeled through equivalent electrical circuits for process parameter extraction. Additionally, a simplified antibody-conjugation strategy was employed for a similar IDE-based analysis of the implications of a key analyte (l-glutamine) binding to the equivalent electrical circuit. Finally, acute microfluidic perfusion modeling was performed to demonstrate the ease of microfluidics integration into such a polymer-metal biosensor platform for potential complimentary localized chemical stimulation. Overall, our work demonstrates the design, development, and characterization of an accessibly designed polymer-metal compound biosensor for electrogenic cellular constructs to facilitate comprehensive MPS data collection.

The synergistic effect of enzymatic detergents on biofilm cleaning from different surfaces

Biofilm growth is a significant source of contamination in the food industry. Enzymes are considered green countermeasures against biofilm formation in the food industry owing to their biodegradability and low toxicity. In this study, the synergistic effect of enzymes was studied against biofilm cleaning from hard surfaces. A mixed-microbial sample was sourced from a meat packaging line and biofilms were grown under high shear conditions on stainless steel and polyethylene surfaces. A model cleaning-in-place (CIP) parallel-plate flow chamber was used for firstly, the enzymatic cleaning and secondly, a disinfection step. The cleaning effectiveness was evaluated in response to different formulations containing non-foaming commercial surfactants among with amylase, protease and lipase at neutral pH. The formulation combining all three enzymes was the most effective, showing a synergy essential for the deformation of biofilm structure and consequently better disinfection of both material surfaces.

Engineered biomaterial and biophysical stimulation as combinatorial strategies to address prosthetic infection by pathogenic bacteria

A plethora of antimicrobial strategies are being developed to address prosthetic infection. The currently available methods for implant infection treatment include the use of antibiotics and revision surgery. Among the bacterial strains, Staphylococcus species pose significant challenges particularly, with regard to hospital acquired infections. In order to combat such life threatening infectious diseases, researchers have developed implantable biomaterials incorporating nanoparticles, antimicrobial reinforcements, surface coatings, slippery/non-adhesive and contact killing surfaces. This review discusses a few of the biomaterial and biophysical antimicrobial strategies, which are in the developmental stage and actively being pursued by several research groups. The clinical efficacy of biophysical stimulation methods such as ultrasound, electric and magnetic field treatments against prosthetic infection depends critically on the stimulation protocol and parameters of the treatment modality. A common thread among the three biophysical stimulation methods is the mechanism of bactericidal action, which is centered on biophysical rupture of bacterial membranes, the generation of reactive oxygen species (ROS) and bacterial membrane depolarization evoked by the interference of essential ion-transport. Although the extent of antimicrobial effect, normally achieved through biophysical stimulation protocol is insufficient to warrant therapeutic application, a combination of antibiotic/ROS inducing agents and biophysical stimulation methods can elicit a clinically relevant reduction in viable bacterial numbers. In this review, we present a detailed account of both the biomaterial and biophysical approaches for achieving maximum bacterial inactivation. Summarizing, the biophysical stimulation methods in a combinatorial manner with material based strategies can be a more potent solution to control bacterial infections. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 2174-2190, 2017.