Topical povidone-iodine, chlorhexidine, bacitracin, and vancomycin are commonly used antiseptic and antimicrobial agents to reduce risk and treat surgical site infections in numerous orthopedic procedures. Chondrocytes potentially may be exposed to these agents during operative procedures. The impact of these topical agents on chondrocyte viability is unclear.
View Article and Find Full Text PDFMany individuals perform cell viability assays as a measure of biocompatibility whether the focus of their research is on novel drug discovery, development of novel biomedical devices, or the study of biointerfacial phenomena. In this tutorial paper, the most commonly used methods available to users to perform biocompatibility testing are discussed. This includes a brief introduction into the benefits and drawbacks of the techniques, including which are best used as screening assays, which are better suited to experienced users, the relative cost of the assays per unit, and what detection techniques are most appropriate for use in conjunction with the assays.
View Article and Find Full Text PDFPoly(-isopropyl acrylamide) (pNIPAM) is a stimulus-responsive polymer that has been of great interest to the bioengineering community. When the temperature is lowered below its lower critical solution temperature (∼32 °C), pNIPAM rapidly hydrates, and adherent cells detach as intact cell sheets. This cell-releasing behavior in a physiologically relevant temperature range has led to NIPAM's use for engineered tissues and other devices.
View Article and Find Full Text PDFPoly(N-isopropyl acrylamide) (pNIPAM) is a "smart" polymer that responds to changes in altering temperature near physiologically relevant temperatures, changing its relative hydrophobicity. Mammalian cells attach to pNIPAM at 37 °C and detach spontaneously as a confluent sheet when the temperature is shifted below the lower critical solution temperature (∼32 °C). A variety of methods have been used to create pNIPAM films, including plasma polymerization, self-assembled monolayers, and electron beam ionization.
View Article and Find Full Text PDFEach year, the United States spends about $20 billion to treat people who have been infected with antibiotic resistant bacteria. Even so, the development of new antibiotics has slowed considerably since the mid-20th century. As a result, researchers are looking into developing synthetic compounds and materials with antimicrobial activities such as those made by the Schanze and Whitten groups [ACS Appl.
View Article and Find Full Text PDFAlthough there is a great deal of research focused on cell sheet engineering from polymers such as poly(N-isopropyl acrylamide) (pNIPAM), the biocompatibility of pNIPAM surfaces and the nature of cellular detachment from this polymer is still unclear. The most extensive study of the mechanism of detachment proposed a two-step process, with a first (passive) phase involving hydration of pNIPAM chains, and the second (active) phase involving cellular metabolism. However, a number of studies performed successful cell sheet detachment from pNIPAM-grafted surfaces at low temperatures which calls this hypothesis into question.
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