Nonequilibrium spectral diffusion due to laser heating in stimulated photon echo spectroscopy of low temperature glasses

A quantitative theory is developed, which accounts for heating artifacts in three-pulse photon echo (3PE) experiments. The heat diffusion equation is solved and the average value of the temperature in the focal volume of the laser is determined as a function of the 3PE waiting time. This temperature is used in the framework of nonequilibrium spectral diffusion theory to calculate the effective homogeneous linewidth of an ensemble of probe molecules embedded in an amorphous host. The theory fits recently observed plateaus and bumps without introducing a gap in the distribution function of flip rates of the two-level systems or any other major modification of the standard tunneling model.Comment: 10 pages, Revtex, 6 eps-figures, accepted for publication in Phys. Rev.

Plasma synthesis of single crystal silicon nanoparticles for novel electronic device applications

Single-crystal nanoparticles of silicon, several tens of nm in diameter, may be suitable as building blocks for single-nanoparticle electronic devices. Previous studies of nanoparticles produced in low-pressure plasmas have demonstrated the synthesis nanocrystals of 2-10 nm diameter but larger particles were amorphous or polycrystalline. This work reports the use of a constricted, filamentary capacitively coupled low-pressure plasma to produce single-crystal silicon nanoparticles with diameters between 20-80 nm. Particles are highly oriented with predominant cubic shape. The particle size distribution is rather monodisperse. Electron microscopy studies confirm that the nanoparticles are highly oriented diamond-cubic silicon.Comment: accepted for publication in Plasma Physics and Controlled Fusion, scheduled for Dec. 2004 F

Silicon particles as trojan horses for potential cancer therapy

[EN] Background: Porous silicon particles (PSiPs) have been used extensively as drug delivery systems, loaded with chemical species for disease treatment. It is well known from silicon producers that silicon is characterized by a low reduction potential, which in the case of PSiPs promotes explosive oxidation reactions with energy yields exceeding that of trinitrotoluene (TNT). The functionalization of the silica layer with sugars prevents its solubilization, while further functionalization with an appropriate antibody enables increased bioaccumulation inside selected cells. Results: We present here an immunotherapy approach for potential cancer treatment. Our platform comprises the use of engineered silicon particles conjugated with a selective antibody. The conceptual advantage of our system is that after reaction, the particles are degraded into soluble and excretable biocomponents. Conclusions: In our study, we demonstrate in particular, specific targeting and destruction of cancer cells in vitro. The fact that the LD50 value of PSiPs-HER-2 for tumor cells was 15-fold lower than the LD50 value for control cells demonstrates very high in vitro specificity. This is the first important step on a long road towards the design and development of novel chemotherapeutic agents against cancer in general, and breast cancer in particular.The authors acknowledge financial support from the following projects FIS2009-07812, MAT2012-35040, PROMETEO/2010/043, CTQ2011-23167, CrossSERS, FP7 MC-IEF 329131, and HSFP (project RGP0052/2012) and Medcom Tech SA. Xiang Yu acknowledges support by the Chinese government (CSC, Nr. 2010691036).Fenollosa Esteve, R.; Garcia-Rico, E.; Alvarez, S.; Alvarez, R.; Yu, X.; Rodriguez, I.; Carregal-Romero, S.... (2014). Silicon particles as trojan horses for potential cancer therapy. Journal of Nanobiotechnology. 12:1-10. https://doi.org/10.1186/s12951-014-0035-7S11012Prasad PN: Introduction to Nanomedicine and Nanobioengineering. Wiley, New York, 2012.Randall CL, Leong TG, Bassik N, Gracias DH: 3D lithographically fabricated nanoliter containers for drug delivery. Adv Drug Del Rev. 2007, 59: 1547-1561. 10.1016/j.addr.2007.08.024.Reibetanz U, Chen MHA, Mutukumaraswamy S, Liaw ZY, Oh BHL, Venkatraman S, Donath E, Neu BR: Colloidal DNA carriers for direct localization in cell compartments by pH sensoring. Biogeosciences. 2010, 11: 1779-1784.Tasciotti E, Liu X, Bhavane R, Plant K, Leonard AD, Price BK, Cheng MM-C, Decuzzi P, Tour JM, Robertson F, Ferrari M: Mesoporous silicon particles as a multistage delivery system for imaging and therapeutic applications. Nat Nano. 2008, 3: 151-157. 10.1038/nnano.2008.34.Park J-H, Gu L, von Maltzahn G, Ruoslahti E, Bhatia SN, Sailor MJ: Biodegradable luminescent porous silicon nanoparticles for in vivo applications. Nat Mater. 2009, 8: 331-336. 10.1038/nmat2398.Hong C, Lee J, Son M, Hong SS, Lee C: In-vivo cancer cell destruction using porous silicon nanoparticles. Anti-Cancer Drugs. 2011, 22: 971-977. 910.1097/CAD.1090b1013e32834b32859cCanham LT: Device Comprising Resorbable Silicon for Boron Capture Neutron Therapy. UK Patent Nr. 0302283.7. Book Device Comprising Resorbable Silicon for Boron Capture Neutron Therapy. UK Patent Nr. 0302283.7 (Editor ed.^eds.). 2003, UK Patent Nr. 0302283.7, CityXiao L, Gu L, Howell SB, Sailor MJ: Porous silicon nanoparticle photosensitizers for singlet oxygen and their phototoxicity against cancer cells. ACS Nano. 2011, 5: 3651-3659. 10.1021/nn1035262.Gil PR, Parak WJ: Composite nanoparticles take Aim at cancer. ACS Nano. 2008, 2: 2200-2205. 10.1021/nn800716j.Gomella LG: Is interstitial hyperthermia a safe and efficacious adjunct to radiotherapy for localized prostate cancer?. Nat Clin Pract Urol. 2004, 1: 72-73. 10.1038/ncpuro0041.Maier-Hauff K, Ulrich F, Nestler D, Niehoff H, Wust P, Thiesen B, Orawa H, Budach V, Jordan A: Efficacy and safety of intratumoral thermotherapy using magnetic iron-oxide nanoparticles combined with external beam radiotherapy on patients with recurrent glioblastoma multiforme. J Neuro-Oncol. 2011, 103: 317-324. 10.1007/s11060-010-0389-0.Lal S, Clare SE, Halas NJ: Nanoshell-enabled photothermal cancer therapy: Impending clinical impact. Acc Chem Res. 2008, 41: 1842-1851. 10.1021/ar800150g.Lee C, Kim H, Hong C, Kim M, Hong SS, Lee DH, Lee WI: Porous silicon as an agent for cancer thermotherapy based on near-infrared light irradiation. J Mater Chem. 2008, 18: 4790-4795. 10.1039/b808500e.Osminkina LA, Gongalsky MB, Motuzuk AV, Timoshenko VY, Kudryavtsev AA: Silicon nanocrystals as photo- and sono-sensitizers for biomedical applications. Appl Phys B. 2011, 105: 665-668. 10.1007/s00340-011-4562-8.Jain PK, Huang X, El-Sayed IH, El-Sayed MA: Noble metals on the nanoscale: optical and photothermal properties and some applications in imaging, sensing, biology, and medicine. Acc Chem Res. 2008, 41: 1578-1586. 10.1021/ar7002804.Serda RE, Godin B, Blanco E, Chiappini C, Ferrari M: Multi-stage delivery nano-particle systems for therapeutic applications. Biochim Biophys Acta. 1810, 2011: 317-329.Xu R, Huang Y, Mai J, Zhang G, Guo X, Xia X, Koay EJ, Qin G, Erm DR, Li Q, Liu X, Ferrari M, Shen H: Multistage vectored siRNA targeting ataxia-telangiectasia mutated for breast cancer therapy. Small. 2013, 9: 1799-1808. 10.1002/smll.201201510.Park JS, Kinsella JM, Jandial DD, Howell SB, Sailor MJ: Cisplatin-loaded porous Si microparticles capped by electroless deposition of platinum. Small. 2011, 7: 2061-2069. 10.1002/smll.201100438.Xue M, Zhong X, Shaposhnik Z, Qu Y, Tamanoi F, Duan X, Zink JI: pH-operated mechanized porous silicon nanoparticles. J Am Chem Soc. 2011, 133: 8798-8801. 10.1021/ja201252e.Canham LT: Bioactive silicon structure fabrication through nanoetching techniques. Adv Mater. 1995, 7: 1033-1037. 10.1002/adma.19950071215.Popplewell JF, King SJ, Day JP, Ackrill P, Fifield LK, Cresswell RG, Di Tada ML, Liu K: Kinetics of uptake and elimination of silicic acid by a human subject: a novel application of 32Si and accelerator mass spectrometry. J Inorganic Biochem. 1998, 69: 177-180. 10.1016/S0162-0134(97)10016-2.Shabir Q, Pokale A, Loni A, Johnson DR, Canham LT, Fenollosa R, Tymczenko M, Rodr guez I, Meseguer F, Cros A, Cantarero A: Medically biodegradable hydrogenated amorphous silicon microspheres. Silicon. 2011, 3: 173-176. 10.1007/s12633-011-9097-4.Chen Y, Wan Y, Wang Y, Zhang H, Jiao Z: Anticancer efficacy enhancement and attenuation of side effects of doxorubicin with titanium dioxide nanoparticles. Int J Nanomed. 2011, 6: 2321-2326.Mackowiak SA, Schmidt A, Weiss V, Argyo C, von Schirnding C, Bein T, Bräuchle C: Targeted drug delivery in cancer cells with Red-light photoactivated mesoporous silica nanoparticles. Nano Lett. 2013, 13: 2576-2583. 10.1021/nl400681f.Li Z, Barnes JC, Bosoy A, Stoddart JF, Zink JI: Mesoporous silica nanoparticles in biomedical applications. Chem Soc Rev. 2012, 41: 2590-2605. 10.1039/c1cs15246g.O Mara WC, Herring B, Hunt P: Handbook of Semiconductor Silicon Technology. Noyes Publication, New Jersey, 1990.Mikulec FV, Kirtland JD, Sailor MJ: Explosive nanocrystalline porous silicon and its Use in atomic emission spectroscopy. Adv Mater. 2002, 14: 38-41. 10.1002/1521-4095(20020104)14:13.0.CO;2-Z.Clement D, Diener J, Gross E, Kunzner N, Timoshenko VY, Kovalev D: Highly explosive nanosilicon-based composite materials. Phys Stat Sol A. 2005, 202: 1357-1359. 10.1002/pssa.200461102.Canham LT: Silicon quantum wire array fabrication by electrochemical and chemical dissolution of wafers. Appl Phys Lett. 1990, 57: 1046-1049. 10.1063/1.103561.Canham LT: Properties of Porous Silicon. INSPEC, United Kindom, 1997.Heinrich JL, Curtis CL, Credo GM, Sailor MJ, Kavanagh KL: Luminescent colloidal silicon suspensions from porous silicon. Science. 1992, 255: 66-68. 10.1126/science.255.5040.66.Littau KA, Szajowski PJ, Muller AJ, Kortan AR, Brus LE: A luminescent silicon nanocrystal colloid via a high-temperature aerosol reaction. J Phys Chem. 1993, 97: 1224-1230. 10.1021/j100108a019.Menz WJ, Shekar S, Brownbridge GPE, Mosbach S, Kōrmer R, Peukert W, Kraft M: Synthesis of silicon nanoparticles with a narrow size distribution: a theoretical study. J Aerosol Sci. 2012, 44: 46-61. 10.1016/j.jaerosci.2011.10.005.Swihart MT, Girshick SL: Thermochemistry and kinetics of silicon hydride cluster formation during thermal decomposition of silane. J Phys Chem B. 1998, 103: 64-76. 10.1021/jp983358e.Fenollosa R, Ramiro-Manzano F, Tymczenko M, Meseguer F: Porous silicon microspheres: synthesis, characterization and application to photonic microcavities. J Mater Chem. 2010, 20: 5210-5214. 10.1039/c0jm00079e.Ramiro-Manzano F, Fenollosa R, Xifré-Pérez E, Garín M, Meseguer F: Porous silicon microcavities based photonic barcodes. Adv Mater. 2011, 23: 3022-3025. 10.1002/adma.201100986.Kastl L, Sasse D, Wulf V, Hartmann R, Mircheski J, Ranke C, Carregal-Romero S, Martínez-López JA, Fernández-Chacón R, Parak WJ, Elsasser HP, Rivera-Gil P: Multiple internalization pathways of polyelectrolyte multilayer capsules into mammalian cells. ACS Nano. 2013, 7: 6605-6618. 10.1021/nn306032k.Schweiger C, Hartmann R, Zhang F, Parak W, Kissel T, Rivera_Gil P: Quantification of the internalization patterns of superparamagnetic iron oxide nanoparticles with opposite charge. J Nanobiotech. 2012, 10: 28-10.1186/1477-3155-10-28.Sanles-Sobrido M, Exner W, Rodr guez-Lorenzo L, Rodríguez-Gonzílez B, Correa-Duarte MA, Álvarez-Puebla RA, Liz-Marzán LM: Design of SERS-encoded, submicron, hollow particles through confined growth of encapsulated metal nanoparticles. J Am Chem Soc. 2009, 131: 2699-2705. 10.1021/ja8088444.Slamon D, Eiermann W, Robert N, Pienkowski T, Martin M, Press M, Mackey J, Glaspy J, Chan A, Pawlicki M, Pinter T, Valero V, Liu MC, Sauter G, von Minckwitz G, Visco F, Bee V, Buyse M, Bendahmane B, Tabah-Fisch I, Lindsay MA, Riva A, Crown J: Adjuvant trastuzumab in HER2-positive breast cancer. N Engl J Med. 2011, 365: 1273-1283. 10.1056/NEJMoa0910383.Agus DB, Gordon MS, Taylor C, Natale RB, Karlan B, Mendelson DS, Press MF, Allison DE, Sliwkowski MX, Lieberman G, Kelsey SM, Fyfe G: Phase I clinical study of pertuzumab, a novel HER dimerization inhibitor, in patients with advanced cancer. J Clin Oncol. 2005, 23: 2534-2543. 10.1200/JCO.2005.03.184.Colombo M, Mazzucchelli S, Montenegro JM, Galbiati E, Corsi F, Parak WJ, Prosperi D: Protein oriented ligation on nanoparticles exploiting O6-alkylguanine-DNA transferase (SNAP) genetically encoded fusion. Small. 2012, 8: 1492-1497. 10.1002/smll.201102284.Franklin MC, Carey KD, Vajdos FF, Leahy DJ, de Vos AM, Sliwkowski MX: Insights into ErbB signaling from the structure of the ErbB2-pertuzumab complex. Cancer Cell. 2004, 5: 317-328. 10.1016/S1535-6108(04)00083-2.Paris L, Cecchetti S, Spadaro F, Abalsamo L, Lugini L, Pisanu ME, Lorio E, Natali PG, Ramoni C, Podo F: Inhibition of phosphatidylcholine-specific phospholipase C downregulates HER2 overexpression on plasma membrane of breast cancer cells. Breast Cancer Res. 2010, 12: R27-10.1186/bcr2575.Fenollosa R, Meseguer F, Tymczenko M: Silicon colloids: from microcavities to photonic sponges. Adv Mater. 2008, 20: 95-98. 10.1002/adma.200701589.Jasinski JM, Gates SM: Silicon chemical vapor deposition one step at a time: fundamental studies of silicon hydride chemistry. Acc Chem Res. 1991, 24: 9-15. 10.1021/ar00001a002.Xiao Q, Liu Y, Qiu Y, Zhou G, Mao C, Li Z, Yao Z-J, Jiang S: Potent antitumor mimetics of annonaceous acetogenins embedded with an aromatic moiety in the left hydrocarbon chain part. J Med Chem. 2010, 54: 525-533. 10.1021/jm101053k.Allman SA, Jensen HH, Vijayakrishnan B, Garnett JA, Leon E, Liu Y, Anthony DC, Sibson NR, Feizi T, Matthews S, Davis BG: Potent fluoro-oligosaccharide probes of adhesion in toxoplasmosis. ChemBioChem. 2009, 10: 2522-2529. 10.1002/cbic.200900425.Chambers DJ, Evans GR, Fairbanks AJ: Elimination reactions of glycosyl selenoxides. Tetrahedron. 2004, 60: 8411-8419. 10.1016/j.tet.2004.07.005.Tomabechi Y, Suzuki R, Haneda K, Inazu T: Chemo-enzymatic synthesis of glycosylated insulin using a GlcNAc tag. Bioorg Med Chem. 2010, 18: 1259-1264. 10.1016/j.bmc.2009.12.031.Pastoriza-Santos I, Gomez D, Perez-Juste J, Liz-Marzan LM, Mulvaney P: Optical properties of metal nanoparticle coated silica spheres: a simple effective medium approach. Phys Chem Chem Phys. 2004, 6: 5056-5060. 10.1039/b405157b

Spectral hole burning: examples from photosynthesis

The optical spectra of photosynthetic pigment–protein complexes usually show broad absorption bands, often consisting of a number of overlapping, ‘hidden’ bands belonging to different species. Spectral hole burning is an ideal technique to unravel the optical and dynamic properties of such hidden species. Here, the principles of spectral hole burning (HB) and the experimental set-up used in its continuous wave (CW) and time-resolved versions are described. Examples from photosynthesis studied with hole burning, obtained in our laboratory, are then presented. These examples have been classified into three groups according to the parameters that were measured: (1) hole widths as a function of temperature, (2) hole widths as a function of delay time and (3) hole depths as a function of wavelength. Two examples from light-harvesting (LH) 2 complexes of purple bacteria are given within the first group: (a) the determination of energy-transfer times from the chromophores in the B800 ring to the B850 ring, and (b) optical dephasing in the B850 absorption band. One example from photosystem II (PSII) sub-core complexes of higher plants is given within the second group: it shows that the size of the complex determines the amount of spectral diffusion measured. Within the third group, two examples from (green) plants and purple bacteria have been chosen for: (a) the identification of ‘traps’ for energy transfer in PSII sub-core complexes of green plants, and (b) the uncovering of the lowest k = 0 exciton-state distribution within the B850 band of LH2 complexes of purple bacteria. The results prove the potential of spectral hole burning measurements for getting quantitative insight into dynamic processes in photosynthetic systems at low temperature, in particular, when individual bands are hidden within broad absorption bands. Because of its high-resolution wavelength selectivity, HB is a technique that is complementary to ultrafast pump–probe methods. In this review, we have provided an extensive bibliography for the benefit of scientists who plan to make use of this valuable technique in their future research