Mechanisms of Pulsed Laser Ablation of Biological Tissues

Abstract

A. Control of Precision 636 B. Control of Thermal Side Effects 636 C. Control of Mechanical Side Effects 637 D. Maximizing the Ablated Mass 637 E. Selective Ablation 637 XII. Outlook and Challenges 638 XIII. Acknowledgment 639 XIV. References 639 Alfred Vogel studied physics and sociology, receiving the University degree for high school teaching and the Ph.D. degree in physics from the Georg-August University of Göttingen, Germany. Later, he earned the degree of Habilitated Doctor of Physics from the University of Lübeck. In 1988, he joined the laser laboratory of the Eye Hospital of the Ludwig-Maximilians University Munich, and in 1992, he moved to the Medical Laser Center Lübeck, where he has been Vice-Chairman since 1999. His research interests include laser−tissue interactions in biomedical applications of photodisruption, pulsed laser ablation, and photocoagulation as well as laser-induced plasma formation, cavitation, and stress waves. Vasan Venugopalan received his B.S. degree in mechanical engineering from the University of California, Berkeley, and S.M. and Sc.D. degrees in mechanical engineering from MIT. He held postdoctoral positions at

Femtosecond-pulsed optical heating of gold nanoparticles

“…11,12 Then, it can trigger a sudden temperature increase at the sub-nanosecond scale and subsequent effects such as acoustic waves used for opto-acoustic imaging 13,14 or bubble formation for nanosurgery. 15 A sharp and brief temperature increase of a NP generated by a femtosecond laser can also contribute to confine the temperature increase at the close vicinity of the NP to avoid extended heating of the whole medium when not desired. 16 Several experimental and numerical approaches aimed at studying the internal processes of heat generation under pulsed illumination and the subsequent effects observed in the surrounding medium, e.g.…”

“…16 Several experimental and numerical approaches aimed at studying the internal processes of heat generation under pulsed illumination and the subsequent effects observed in the surrounding medium, e.g. temperature and pressure variations, [17][18][19] acoustic wave generation, 18 vibration modes, [20][21][22] , cell apoptosis, 11 drug release 9,23 nanosurgery, 15,24 bubble formation, [25][26][27][28] NP shape modification 29 and melting, [29][30][31] nanosecondpulses for biomedical applications, 32,33 extreme thermodynamics conditions. [33][34][35][36][37] In this paper, we present and use a versatile numerical framework to investigate theoretically and numerically the evolution of the temperature distribution of a gold nanoparticle immersed in water when shined by a femtosecond-pulsed laser.…”

Photothermally enhanced drug release by κ-carrageenan hydrogels reinforced with multi-walled carbon nanotubes

“…For example, CNTs absorb NIR light and convert the absorbed energy into heat very effectively [17]. The ability of the CNTs to generate heat upon NIR irradiation is a powerful tool that has 45 been investigated for applications such as cancer hyperthermia [18][19][20] and remotely controlled drug delivery [21][22][23]. CNTs can therefore act as light activated nanoheaters to induce phase transitions of thermosensitive hydrogels, as recently reported for agarose [23] and poly(N-isoprylacrylamide) based hydrogels 50 [22][23][24].…”

“…After incorporation of non-functionalized (Figure 3(b)) and 40 functionalized (Figure 3(c)) MWCNTs, the carrageenan flakes appear larger, thus suggesting that the nanotubes have promoted the association of carrageenan helices in larger extension, which is in agreement with the DMA results discussed above. Hydrogels whose range thermo-sensitivity is slightly higher than 45 37 ºC and up to about 44 ºC are required for their use as thermally activated drug carriers, because this is the temperature range acceptable for living cells. Therefore, the potential of the MWCNT/carrageenan composites as thermosensitive carriers was first assessed by measuring the gel-sol transition by DSC.…”

Qualitative tissue differentiation by analysing the intensity ratios of atomic emission lines using laser induced breakdown spectroscopy (LIBS): prospects for a feedback mechanism for surgical laser systems

“…Since the atoms found in the plasma are mostly the atoms from the processed samples, monitoring the emissions from these atoms is used to qualitatively and quantitatively identify the different target samples [25]. The emissions at different wavelengths provide qualitative information whereas the intensity level of the emissions provides quantitative information [22,26].…”