7 research outputs found
Materials for multifunctional balloon catheters with capabilities in cardiac electrophysiological mapping and ablation therapy
Developing advanced surgical tools for minimally invasive procedures represents an activity of central importance to improving human health. A key challenge is in establishing biocompatible interfaces between the classes of semiconductor device and sensor technologies that might be most useful in this context and the soft, curvilinear surfaces of the body. This paper describes a solution based on materials that integrate directly with the thin elastic membranes of otherwise conventional balloon catheters, to provide diverse, multimodal functionality suitable for clinical use. As examples, we present sensors for measuring temperature, flow, tactile, optical and electrophysiological data, together with radiofrequency electrodes for controlled, local ablation of tissue. Use of such 'instrumented' balloon catheters in live animal models illustrates their operation, as well as their specific utility in cardiac ablation therapy. The same concepts can be applied to other substrates of interest, such as surgical gloves.
Electronic sensor and actuator webs for large-area complex geometry cardiac mapping and therapy
Curved surfaces, complex geometries, and time-dynamic deformations
of the heart create challenges in establishing intimate, nonconstraining
interfaces between cardiac structures and medical
devices or surgical tools, particularly over large areas.We constructed
large area designs for diagnostic and therapeutic stretchable sensor
and actuator webs that conformally wrap the epicardium, establishing
robust contact without sutures, mechanical fixtures, tapes, or
surgical adhesives. These multifunctional web devices exploit open,
mesh layouts and mount on thin, bio-resorbable sheets of silk to
facilitate handling in a way that yields, after dissolution, exceptionally
low mechanical moduli and thicknesses. In vivo studies in rabbit
and pig animal models demonstrate the effectiveness of these device
webs for measuring and spatially mapping temperature, electrophysiological
signals, strain, and physical contact in sheet and
balloon-based systems that also have the potential to deliver energy
to perform localized tissue ablation.192991sciescopu
Electronic sensor and actuator webs for large-area complex geometry cardiac mapping and therapy
Curved surfaces, complex geometries, and time-dynamic deformations of the heart create challenges in establishing intimate, non-constraining interfaces between cardiac structures and medical devices or surgical tools, particularly over large areas. We constructed large area designs for diagnostic and therapeutic stretchable sensor and actuator webs that conformally wrap the epicardium, establishing robust contact without sutures, mechanical fixtures, tapes, or surgical adhesives. These multifunctional web devices exploit open, mesh layouts and mount on thin, bio-resorbable sheets of silk to facilitate handling in a way that yields, after dissolution, exceptionally low mechanical moduli and thicknesses. In vivo studies in rabbit and pig animal models demonstrate the effectiveness of these device webs for measuring and spatially mapping temperature, electrophysiological signals, strain, and physical contact in sheet and balloon-based systems that also have the potential to deliver energy to perform localized tissue ablation.
Localized Rho GTPase Activation Regulates RNA Dynamics and Compartmentalization in Tumor Cell Protrusions*Sā
mRNA trafficking and local protein translation are associated with
protrusive cellular domains, such as neuronal growth cones, and deregulated
control of protein translation is associated with tumor malignancy. We show
here that activated RhoA, but not Rac1, is enriched in pseudopodia of
MSV-MDCK-INV tumor cells and that Rho, Rho kinase (ROCK), and myosin II
regulate the microtubule-independent targeting of RNA to these tumor cell
domains. ROCK inhibition does not affect pseudopodial actin turnover but
significantly reduces the dynamics of pseudopodial RNA turnover. Gene array
analysis shows that 7.3% of the total genes analyzed exhibited a greater than
1.6-fold difference between the pseudopod and cell body fractions. Of these,
only 13.2% (261 genes) are enriched in pseudopodia, suggesting that only a
limited number of total cellular mRNAs are enriched in tumor cell protrusions.
Comparison of the tumor pseudopod mRNA cohort and a cohort of mRNAs enriched
in neuronal processes identified tumor pseudopod-specific signaling networks
that were defined by expression of M-Ras and the Shp2 protein phosphatase.
Pseudopod expression of M-Ras and Shp2 mRNA were diminished by ROCK inhibition
linking pseudopodial Rho/ROCK activation to the localized expression of
specific mRNAs. Pseudopodial enrichment for mRNAs involved in protein
translation and signaling suggests that local mRNA translation regulates
pseudopodial expression of less stable signaling molecules as well as the
cellular machinery to translate these mRNAs. Pseudopodial Rho/ROCK activation
may impact on tumor cell migration and metastasis by stimulating the
pseudopodial translocation of mRNAs and thereby regulating the expression of
local signaling cascades