Medically Biodegradable Hydrogenated Amorphous Silicon Microspheres

[EN] Hydrogenated amorphous silicon colloids of low surface area (<5 m(2)/g) are shown to exhibit complete in-vitro biodegradation into orthosilicic acid within 10-15 days at 37 degrees C. When converted into polycrystalline silicon colloids, by high temperature annealing in an inert atmosphere, microparticle solubility is dramatically reduced. The data suggests that amorphous silicon does not require nanoscale porosification for full in-vivo biodegradability. This has significant implications for using a-Si:H coatings for medical implants in general, and orthopedic implants in particular. The high sphericity and biodegradability of submicron particles may also confer advantages with regards to contrast agents for medical imaging.This work has been partially supported by the Spanish CICyT projects, FIS2009-07812, Consolider CSD2007-046, MAT2009-010350 and PROMETEO/2010/043.Shabir, Q.; Pokale, A.; Loni, A.; Johnson, DR.; Canham, L.; Fenollosa Esteve, R.; Tymczenko, MK.... (2011). Medically Biodegradable Hydrogenated Amorphous Silicon Microspheres. Silicon. 3(4):173-176. https://doi.org/10.1007/s12633-011-9097-4S17317634Salonen J, Kaukonen AM, Hirvonen J, Lehto VP (2008) J Pharmaceutics 97:632–53Anglin EJ, Cheng L, Freeman WR, Sailor MJ (2008) Adv Drug Deliv Rev 60:1266–77O’Farrell N, Houlton A, Horrocks BR (2006) Int J Nanomedicine 1:451–72Canham LT (1995) Adv Mater 7:1037, PCT patent WO 97/06101,1999Park JH, Gui L, Malzahn G, Ruoslahti E, Bhatia SN, Sailor MJ (2009) Nature Mater 8:331–6Cullis AG, Canham LT, Calcott PDJ (1997) J Appl Phys 82:909–66Canham LT, Reeves CR (1996) Mat Res Soc Symp 414:189–90Edell DJ, Toi VV, McNeil VM, Clark LD (1992) IEEE Trans Biomed Eng 39:635–43Fenollosa R, Meseguer F, Tymczenko M (2008) Adv Mater 20:95Fenollosa R, Meseguer F, Tymczenko M, Spanish Patent P200701681, 2007Pell LE, Schricker AD, Mikulec FV, Korgel BA (2004) Langmuir 20:6546Xifré-Perez E, Fenollosa R, Meseguer F (2011) Opt Express 19:3455–63Fenollosa R, Ramiro-Manzano F, Tymczenko M, Meseguer F (2010) J Mater Chem 20:5210Xifré-Pérez E, Domenech JD, Fenollosa R, Muñoz P, Capmany J, Meseguer F (2011) Opt Express 19–4:3185–92Rodriguez I, Fenollosa R, Meseguer F, Cosmetics & Toiletries 2010;42–49Ramiro-Manzano F, Fenollosa R, Xifré-Pérez E, Garín M, Meseguer F (2011) Adv Mater 23:3022–3025. doi: 10.1002/adma.201100986Iler RK (1979) Chemistry of silica: solubility, polymerization, colloid & surface properties & biochemistry. Wiley, New YorkTanaka K, Maruyama E, Shimado T, Okamoto H (1999) Amorphous silicon. Wiley, New York, NYPatterson AL (1939) Phys Rev 56:978–82Canham LT, Reeves CL, King DO, Branfield PJ, Gabb JG, Ward MC (1996) Adv Mater 8:850–2Iler RK In: Chemistry of silica: solubility, polymerization, colloid & surface properties &Biochemistry. Wiley, New York, NYFinnie KS, Waller DJ, Perret FL, Krause-Heuer AM, Lin HQ, Hanna JV, Barbe CJ (2009) J Sol-Gel Technol 49:12–8Zhao D, Huo Q, Feng J, Chmelka BF, Stucky GD (1998) J Am Chem Soc 120:6024–36Fan D, Akkaraju GR, Couch EF, Canham LT, Coffer JL (2010) Nanoscale 1:354–61Tasciotti E, Godin B, Martinez JO, Chiappini C, Bhavane R, Liu X, Ferrari M (2011) Mol Imaging 10:56–

Silicon colloids: From microcavities to photonic sponges

A study was conducted to demonstrate a method for obtaining silicon colloids of varying diameters. Silicon microspheres were obtained through chemical vapor deposition techniques. It was found that under controlled chemical reaction conditions, silicon colloids nucleate and grow in disilane gas. The silicon colloidal particles became highly spherical in the disilane gas, due to surface tension forces. It was also observed that the particles diffused in the gas, producing a number of microspheres that deposited on the walls of the gas reactor, or onto any other substrate introduced into the reactor. Microspheres were found isolated, as clusters of a few units and as agglomerates of many spheres, called photonic sponges. It was also demonstrated that microspheres can be obtained from photonic sponges through a mild grinding process that preserved the spherical quality of particles.Peer Reviewe

Microspheres of silicon and photonic sponges, method for production and uses thereof in the manufacture of photonic devices

The invention concerns a microsphere of silicon with a diameter between 0.1 and 50 micras capable of functioning as an optical microcavity with Mie resonant modes for wavelengths in the range between 1 and 15 micras, and a photonic sponge formed from the former. Preparation thereof is achieved by means of a simple method based on the decomposition by heating of the gaseous precursors. The use of these microspheres and photonic sponges are useful for manufacturing photonic devices, for example, solar cells, photo diodes, lasers and sensors.Las preocupaciones de la invención una microesfera de silicios con un diámetro entre 0.1 y 50 micras capaces de funcionamiento como microcavity óptico con los modos resonantes de Mie para las longitudes de onda en el intervalo entre 1 y 15 micras, y una esponja photonic formada del conformador. La preparación de eso es conseguida por medio de un método sencillo basado en la descomposición por el calentamiento de los precursores gaseosos. El uso de estas microesferas y son photonic de las esponjas útiles para los dispositivos photonic de la fabricación, por ejemplo, células solares, fotodiodos, láseres y sensores.Peer reviewedConsejo Superior de Investigaciones Científicas (España)A1 Solicitud de patentes con informe sobre el estado de la técnic

Colloidal crystal wires

A study was conducted to demonstrate the infiltration of polystyrene (PS) spheres inside the pores of silicon membrane. The study conducted significant investigations of the particle arrangement for D values between 1 and 3. The study employed charge-stabilized colloidal particles to conduct investigations. It was demonstrated that sulphate-stabilized PS spheres were infiltrated into the silicon membrane. A combination of PS spheres, with different diameters and high-quality porous silicon membranes were used to cover the values of D and conduct investigations. The silicon membrane was manufactured by electrochemical etching procedure, which allows very long pores with vertical walls. It was also observed that the pore diameter decreases to a value around 50% or less at the bottom from a normal value at the surface.Peer Reviewe

Silicon Colloids: a new enabling nanomaterial

We have recently developed a new type of silicon structure that we refer to as a silicon colloid. This new material consists of almost perfectly spherical silicon micro- and nanoparticles with a very smooth surface. They are able to trap light very efficiently in a large-span frequency range covering the visible to the far infrared regions. Silicon colloids can be thought of as a completely new material for scientific and technological purposes, with manifold applications covering electronics, photonics, cosmetics, or paints, among others. Here, we report on the synthesis of polycrystalline, amorphous, and porous silicon colloids, as well as their optical properties, some applications concerning light filters, and photonic bonding.Meseguer Rico, FJ.; Fenollosa Esteve, R.; Rodríguez, M.; Xifre Perez, E.; Ramiro Manzano, F.; Garin, M.; Tymczenko, MK. (2011). Silicon Colloids: a new enabling nanomaterial. Journal of Applied Physics. 109(10):24241-24246. doi:10.1063/1.358188024241242461091

Colloidal crystal wires

Several configurations of colloidal wires are obtained by infiltration of charge-stabilized polystyrene spheres into cylindrical pores of a silicon membrane (see figure). As channel dimensions are comparable to those of particles, wirelike arrangements are governed by the ratio between the pore diameter and the particle diameter. Also, Coulomb repulsion between particles plays a very important role in the particle ordering.Peer ReviewedPostprint (published version

Colloidal crystal wires

Several configurations of colloidal wires are obtained by infiltration of charge-stabilized polystyrene spheres into cylindrical pores of a silicon membrane (see figure). As channel dimensions are comparable to those of particles, wirelike arrangements are governed by the ratio between the pore diameter and the particle diameter. Also, Coulomb repulsion between particles plays a very important role in the particle ordering.Peer Reviewe