Developing Biosensors for Monitoring Orthopedic Tissue Growth

2006 ◽  
Vol 950 ◽  
Author(s):  
Sirinrath Sirivisoot ◽  
Chang Yao ◽  
Xingcheng Xiao ◽  
Brian W. Sheldon ◽  
Thomas J. Webster
Keyword(s):  
Biodegradable Polymer ◽  
Bone Growth ◽  
Chemical Vapor ◽  
Deposition Process ◽  
Tissue Growth ◽  
Calcium Deposition ◽  
Bone Regrowth ◽  
And Control

ABSTRACTThe objective of this in vitro present study was to create a biosensor which can monitor in situ orthopedic tissue growth juxtaposed to a newly implanted orthopedic material. This biosensor has unique properties including the ability to sense, detect, and control bone regrowth. Such a biosensor is useful not only in regenerating tissue necessary for orthopedic implant success, but also to aid in informing an orthopedic surgeon whether sufficient new bone growth occurred. If the sensor determines that insufficient new bone growth occurred, the sensor can also act in an intelligent manner to release bone growth factors to increase bone formation. The primary biomaterial in this biosensor is anodized Ti, developed by chemical etching and passivation treatments. Carbon nanotubes (CNTs), because of their electrical and mechanical properties, are essential to consider when designing such biosensors since they will be used to apply and measure conductivity changes as new bone grows next to the implant. For this, parallel multiwall CNTs were grown from the pores of the anodized Ti by a chemical vapor deposition process. Lastly, these sensors will be composed of a conductive, biodegradable, polymer layer that degrades when bone grows and, consequently, undergoes a change in conductivity that can be measured by the CNTs grown out of the anodized Ti. This conductive, biodegradable polymer consists of polypyrrole (which is conductive) and poly-lactic-co-glycolic acid (which is biodegradable). Preliminaryin vitroresults suggest that osteoblast functions (specifically alkaline phosphatase activity and calcium deposition) on CNTs grown on anodized Ti are significantly enhanced when compared to anodized Ti and currently-used Ti; thus, it is anticipated that bone growth could be enhanced on these novel biomaterial sensors.

scholarly journals Synthesis of Poly(methacrylic acid-co-butyl acrylate) Grafted onto Functionalized Carbon Nanotube Nanocomposites for Drug Delivery

Polymers ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 533 ◽  
Author(s):  
Josué A. Torres-Ávalos ◽  
Leonardo R. Cajero-Zul ◽  
Milton Vázquez-Lepe ◽  
Fernando A. López-Dellamary ◽  
Antonio Martínez-Richa ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Drug Delivery ◽  
Methacrylic Acid ◽  
Butyl Acrylate ◽  
Chemical Vapor ◽  
Vis Spectroscopy ◽  
Ir And Raman Spectroscopies ◽  
Ft Ir

Design of a smart drug delivery system is a topic of current interest. Under this perspective, polymer nanocomposites (PNs) of butyl acrylate (BA), methacrylic acid (MAA), and functionalized carbon nanotubes (CNTsf) were synthesized by in situ emulsion polymerization (IEP). Carbon nanotubes were synthesized by chemical vapor deposition (CVD) and purified with steam. Purified CNTs were analyzed by FE-SEM and HR-TEM. CNTsf contain acyl chloride groups attached to their surface. Purified and functionalized CNTs were studied by FT-IR and Raman spectroscopies. The synthesized nanocomposites were studied by XPS, 13C-NMR, and DSC. Anhydride groups link CNTsf to MAA–BA polymeric chains. The potentiality of the prepared nanocomposites, and of their pure polymer matrices to deliver hydrocortisone, was evaluated in vitro by UV–VIS spectroscopy. The relationship between the chemical structure of the synthesized nanocomposites, or their pure polymeric matrices, and their ability to release hydrocortisone was studied by FT-IR spectroscopy. The hydrocortisone release profile of some of the studied nanocomposites is driven by a change in the inter-associated to self-associated hydrogen bonds balance. The CNTsf used to prepare the studied nanocomposites act as hydrocortisone reservoirs.

scholarly journals Carbon-Involved Near-Surface Evolution of Cobalt Catalyst during Reaction: An in-situ Study

2020 ◽  
Author(s):  
Feng Yang ◽  
Haofei Zhao ◽  
Wu Wang ◽  
Qidong Liu ◽  
Xu Liu ◽  
...  
Keyword(s):  
Chemical Vapor ◽  
Carbon Diffusion ◽  
Deposition Process ◽  
Catalytic Performance ◽  
Surface Evolution ◽  
Near Surface ◽  
Co Catalysts ◽  
Transmission Electron ◽  
Walled Carbon Nanotubes

Abstract When carbon-containing species are involved in reactions catalyzed by transition metals at high temperature, the diffusion of carbon on/in catalysts dramatically influence the catalytic performance. Acquiring information on the carbon-diffusion-involved evolution of catalysts at atomic level is crucial for understanding the reaction mechanism yet also challenging. For the chemical vapor deposition process of single-walled carbon nanotubes (SWCNTs), we developed methodologies to record in-situ the near-surface structural and chemical evolution of Co catalysts with carbon permeation using an aberration-corrected environmental transmission electron microscope and the synchrotron X-ray absorption spectroscopy. The nucleation and growth of SWCNTs were linked with the partial carbonization of catalysts and the alternating dissolvement-precipitation of carbon in catalysts. The dynamics of carbon atoms in catalysts brings deeper insight into the growth mechanism of SWCNTs and also sheds light on inferring mechanisms of more reactions. The methodologies developed here will find broad applications in studying catalytic and other processes.

Structural Defects of Silicon Epitaxy and Epi/Substrate Interface Related to Improper In-Situ Surface Cleaning at Low Temperatures

1990 ◽  
Vol 202 ◽  
Author(s):  
Tri-Rung Yew ◽  
Rafael Reif
Keyword(s):  
Defect Formation ◽  
Chemical Vapor ◽  
Deposition Process ◽  
Surface Cleaning ◽  
Structural Defects ◽  
Plasma Cleaning ◽  
Substrate Interface ◽  
Silicon Epitaxy ◽  
Pressure Chemical

ABSTRACTThis paper investigates the defect formation at the epi/substrate interface and epitaxial layers due to an improper in–situ Ar or Ar/H2 plasma cleaning at 500–800 °C Deposition process was carried out immediately after the in–situ cleaning process by ultralow pressure chemical vapor deposition process (ULPCVD) from SiH4/H2. Characteristics of the defects and their relationship with damage or impurity contaminations at the interface are presented. Finally, an optimum cleaning condition which ensures high quality epitaxial growth is addressed.

Plasma Enhanced OMCVD Atomic Layered Growth of Y-BA-CU Oxide Films

1991 ◽  
Vol 222 ◽  
Author(s):  
S. J. Duray ◽  
D. B. Buchholz ◽  
S. N. Song ◽  
D. S. Richeson ◽  
J. B. Ketterson ◽  
...  
Keyword(s):  
Oxide Films ◽  
Chemical Vapor ◽  
Complex Oxide ◽  
Deposition Process ◽  
Composition And Structure ◽  
Layered Growth ◽  
Background Gas ◽  
Post Deposition ◽  
Complex Oxide Films

ABSTRACTWe report the results of a pulsed organo-metallic beam epitaxy (POMBE) process for growing complex oxide films at low background gas pressure (10-4 -10-2 torr) and low substrate temperature (600 to 700 C) using organo-metallic precursors in an oxygen plasma environment. Our results show that POMBE can extend the capability of organo-metallic chemical vapor deposition to growing complex oxide films with high precision both in composition and structure without the need for post-deposition oxidation and heat treatments. The growth of phase-pure, highly oriented Y-Ba-Cu-O superconducting oxide films ([Tc (R=0)=90.5K] and Jc (77K, 50K gauss)=l.l×105 A/cm2) is given as an example. Similar to the pulsed laser deposition process, the POMBE method has the potential for in-situ processing of multilayer structures (e.g. junctions).

In-Situ Observation of Chemical Vapor Deposition of Thin Sige Films by Optical Reflection Interferometry

1994 ◽  
Vol 375 ◽  
Author(s):  
G. Ritter ◽  
B. Tillack ◽  
M. Weidner ◽  
F. G. Böbel ◽  
B. Hertel
Keyword(s):  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Deposition Process ◽  
Ex Situ ◽  
In Situ Observation ◽  
Optical Reflection ◽  
Initial Stage

AbstractChemical Vapor Deposition of Si1-x Gex – films on Si (100) and of polycrystalline Si1-x Gex, layers on SiO2 – coated substrates have been performed at a pressure of 200 Pa in the temperature range of 500°C – 800°C, correspondingly. To observe the growth process and to characterize the growing thin films at deposition conditions an optical reflection interferometer (PYRITIERS) has been used. Comparing the data obtained at growth temperature with ex- situ measurements by spectroscopic ellipsometry the temperature dependence of optical constants of SiGe films have been evaluated. The reflectivity measurements during the deposition process allow to study the quality of the heteroepitaxial film, even in the initial stage of epitaxial growth.

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