Multiscale Thermal Property Measurements for Biomedical Applications

Abstract

Bioheat transfer-based innovations in health care include applications such as focal treatments for cancer and cardiovascular disease and the preservation of tissues and organs for transplantation. In these applications, the ability to preserve or destroy a biomaterial is directly dependent on its temperature history. Thus, thermal measurement and modeling are necessary to either avoid or induce the injury required. In this review paper, we will first define and discuss thermal conductivity and calorimetric measurements of biomaterials in the cryogenic (<−40 °C), subzero (<0 °C), hypothermic (<37 °C), and hyperthermic (>37 °C) regimes. For thermal conductivity measurements, we review the use of 3ω and laser flash techniques for measurement of thermal conductivity in thin (1 μm−2 mm thick), anisotropic, and/or multilayered tissues. At the nanoscale, we review the use of pump−probe and scanning probe methods to measure thermal conductivity at short temporal scales (10 ps−100 ns) and spatial scales (1 nm−1 μm), particularly in the coating and surrounding medium around metallic nanoparticles (1 nm−20 nm). For calorimetric techniques, we review differential scanning calorimetry (DSC), which is intrinsically at the microscale (e.g., tissue pieces or millions of cells in media). DSC is used with large sample mass (∼3−100 mg) over wide temperature ranges (−180 to 750 °C) with low-temperature scanning rates (<750 °C/min). The need to assess smaller samples at higher rates has led to the development of nanocalorimetry on a silicon based membrane. Here the sample weight is as low as 10 ng, thereby allowing ultra-rapid heating rates (∼1 × 10 7 C/min). Finally, we discuss various opportunities that are driving the need for new micro-and nanoscale thermal measurements.

Au@Pd Nanopopcorn and Aptamer Nanoflower Assisted Lateral Flow Strip for Thermal Detection of Exosomes

“…Similar signal outputs were observed in both sides of the negative LFS evaluation, while a much stronger thermal signal (Figure b) and higher temperature contrast (Figure c) were obtained in the opposite side of the positive LFS that in the same side. The likely explanation for this observation is that the thermal conductivity measurement technique used here, namely, the “laser flash method”, may have endowed the opposite side mode with a superior film-based thermal generation ability . This approximates to an instantaneous heat source heating one side of a sample, while, on the opposite side, the thermal energy diffusing across the sample causes the rise in temperature .…”

Applications and regulatory of nanotechnology‐based innovative in vitro diagnostics

“…NMs are promising candidates as signal generators for IVDs and provide more options for conventional IVDs, benefiting from their unique size‐dependent physical and chemical properties, such as optical, 4 thermodynamic, 5 and magnetic performances 6 . In comparison with fluorescence probes, quantum dots (QDs), 7–10 up‐conversion nanoparticles (UCNPs), 11–14 and long‐persistent NMs 15–17 exhibited the superior features of high fluorescence brightness, good stability, and low background noise.…”

Integrated Multiscale Biomaterials Experiment and Modeling

“…Unlocking the thermal properties and distribution of thermal energy across scales and tissue components is essential for a broad range of thermal ablation therapies and for cryopreservation of tissues and organs for transplantation. As reviewed by Natesan and Bischof, thermal conductivity and calorimetric measurements are particularly challenging in anisotropic and layered tissues. This challenge is complicated by the hierarchical nature of the tissues, and by uncertainties in the properties of the interfaces between cells and ECM.…”