Poly(vinyl alcohol) tissue phantoms as a robust<i>in vitro</i>model for heat transfer

Coffel, Joel; Nuxoll, Eric

doi:10.1080/00914037.2016.1171222

Cited by 4 publications

(3 citation statements)

References 35 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Equation 1 indicates an equivalence between thermal shock temperature and exposure time, with the same degree of population reduction possible across a range of temperatures, each with a corresponding exposure time. Combined with thermal modeling [47] and an estimation of resulting tissue damage based on the local Cumulative Equivalent Minutes at 43 °C (CEM43) [48, 49], multiple optimum thermal shock combinations may be calculated to result in the same bacterial population reduction and the same depth of tissue damage above a given CEM43 threshold. For instance, while a 70 °C, 1 min shock in conjunction with antibiotics has been shown to eliminate biofilms [50], it also results in 2.5 mm of adjacent tissue experiencing at least 200 CEM43.…”

Section: Discussionmentioning

confidence: 99%

Thermal shock susceptibility and regrowth ofPseudomonas aeruginosabiofilms

Ricker

Aljaafari

Bader

et al. 2018

International Journal of Hyperthermia

Self Cite

View full text Add to dashboard Cite

Biofilms on implanted medical devices cause thousands of patients each year to undergo multiple surgeries to remove and replace the implant, driving billions of dollars in increased health care costs due to the lack of viable treatment options for in situ biofilm eradication. Remotely activated localised heating is under investigation to mitigate these biofilms; however, little is known about the temperatures required to kill the biofilms. To better understand the required parameters this study investigated the thermal susceptibility of biofilms as a function of their fluidic and chemical environment during growth, as well as their propensity for regrowth following thermal shock. Pseudomonas aeruginosa biofilms were cultured in shaker plate fluidic conditions in four different growth media, then thermally shocked at various temperatures and exposure times. Biofilms were re-incubated to determine their regrowth potential following thermal shocks of various intensities. Results indicate that growth media has little impact on thermal susceptibility, while fluidic conditions strongly influence susceptibility to modest thermal shocks. This effect disappears, however, with increasingly aggressive shocks, reducing biofilm populations by up to 5 orders of magnitude. Regrowth studies indicate a critical post-shock bacterial loading (∼10 CFU/cm) below which the biofilms were no longer viable, while biofilms above that loading slowly regrew to their previous population density.

show abstract

Section: Discussionmentioning

confidence: 99%

Thermal shock susceptibility and regrowth ofPseudomonas aeruginosabiofilms

Ricker

Aljaafari

Bader

et al. 2018

International Journal of Hyperthermia

Self Cite

View full text Add to dashboard Cite

show abstract

“…By equipping the implant with a magnetically susceptible coating, its surface temperature can be raised on demand by exposing it to an alternating magnetic field (Coffel & Nuxoll 2015). The use of a coating to heat the implant surface would result in some tissue damage, but may significantly reduce tissue loss compared to the current method of treatment for biofilm infected implants (Coffel & Nuxoll 2016). The Cumulative Equivalent Minutes at 43 °C (CEM43) (Dewhirst et al 2003; Yarmolenko et al 2011) varies strongly with the surrounding heat sink (for example, perfusive blood carrying away the heat).…”

Section: Discussionmentioning

confidence: 99%

Synergistic effects of heat and antibiotics on Pseudomonas aeruginosa biofilms

Ricker

Nuxoll

2017

Biofouling

Self Cite

View full text Add to dashboard Cite

Upon formation of a biofilm, bacteria undergo several changes that prevent eradication with antimicrobials alone. Due to this resistance, the standard of care for infected medical implants is explantation of the infected implant and surrounding tissue, followed by eventual reimplantation of a replacement device. Recent studies have demonstrated the efficacy of heat shock for biofilm eradication. To minimize the heat required for in situ biofilm eradication, this study investigated the hypothesis that antibiotics, while ineffective by themselves, may substantially increase heat shock efficacy. The combined effect of heat and antibiotics on Pseudomonas aeruginosa biofilms was quantified via heat shock in combination with ciprofloxacin, tobramycin, or erythromycin at multiple concentrations. Combined treatments had synergistic effects for all antibiotics for heat shock conditions of 60 °C for 5 min to 70 °C for 1 min, indicating an alternative to surgical explantation.

show abstract

“…In order to model the heat transfer properties occurring into soft tissues surrounding the fiducial markers in case of MFH treatments, hydrogel phantoms based on poly(vinyl-alcohol) (PVA) crosslinked with glutaraldehyde (GTA) were prepared. Indeed, GTA-PVA gel is a well-known matrix able to mimic efficiently the physiological thermal properties of tissues [19]. The procedure used for the hydrogel preparation, described in detail elsewhere [20,21], is here briefly summarized.…”

Section: Phantomsmentioning

confidence: 99%