Digital Pulsed Force Mode AFM and Confocal Raman Microscopy in Drug-Eluting Coatings Research

2011 ◽  
Vol 1318 ◽  
Author(s):  
G. Haugstad ◽  
K. Wormuth
Keyword(s):  
Structural Changes ◽  
Raman Microscopy ◽  
Confocal Raman Microscopy ◽  
Characterization Methods ◽  
Drug Elution ◽  
Force Mode ◽  
Confocal Raman ◽  
Amorphous Drug ◽  
Pulsed Force Mode Afm ◽  
Time Frames

ABSTRACTControlled release of amorphous drug from a polymer matrix depends intimately upon the degree of mixing of drug and polymer, the susceptibility of the drug to crystallization, and the ability of the drug to dissolve and diffuse through water-swollen polymer. Characterization methods ideally would follow these processes on the molecular level in situ and in real time. We move closer to this ideal state of characterization through application of two imaging methods: digital pulsed force mode atomic force microscopy (D-PFM AFM) and confocal Raman microscopy (CRM). We examine model spin-coated films ~1 μm thick containing the drug dexamethasone dispersed in poly(n-alkyl methacrylate) homopolymer and blend coatings. We report aqueous-immersion studies of surface and subsurface structural changes due to drug elution over time frames ranging from very fast (a few minutes) to slow (tens of hours).

scholarly journals Structural changes in alginate-based microspheres exposed to in vivo environment as revealed by confocal Raman microscopy

2018 ◽  
Vol 8 (1) ◽  
Author(s):  
Zuzana Kroneková ◽  
Michal Pelach ◽  
Petra Mazancová ◽  
Lucia Uhelská ◽  
Dušana Treľová ◽  
...  
Keyword(s):  
Structural Changes ◽  
Raman Microscopy ◽  
Confocal Raman Microscopy ◽  
Confocal Raman

Single Layer Graphene for Estimation of Axial Spatial Resolution in Confocal Raman Microscopy Depth Profiling

2018 ◽  
Vol 91 (1) ◽  
pp. 1049-1055 ◽  
Author(s):  
Carol Korzeniewski ◽  
Jay P. Kitt ◽  
Saheed Bukola ◽  
Stephen E. Creager ◽  
Shelley D. Minteer ◽  
...  
Keyword(s):  
Spatial Resolution ◽  
Depth Profiling ◽  
Single Layer ◽  
Raman Microscopy ◽  
Single Layer Graphene ◽  
Confocal Raman Microscopy ◽  
Layer Graphene ◽  
Confocal Raman

scholarly journals Real-Time Drug Release Imaging From Nanocomposite Drug and Polymer Coatings

2008 ◽  
Vol 2 (2) ◽  
Author(s):  
Jinping Dong ◽  
Greg Haugstad ◽  
Chris Frethem ◽  
John Foley ◽  
Bob Hoerr ◽  
...  
Keyword(s):  
Drug Release ◽  
Real Time ◽  
Polymer Coatings ◽  
Raman Microscopy ◽  
Prolonged Release ◽  
Confocal Raman Microscopy ◽  
Release Process ◽  
Force Microscopy ◽  
Confocal Raman ◽  
Model Drug

The ElectroNanospray process (Nanocopoeia, Inc) transforms drugs and polymers into many nanoscale material states including powders, liquids, encapsulated particles, and coatings. This allows application of polymers and drugs to the surface of medical devices such as coronary stents in a single-stage process. A model drug delivery system consisting of a polymer matrix (arborescent polyisobutylene-polystyrene, or arbIBS) and either dexamethasone or sirolimus was studied by various characterization techniques. Modification of ElectroNanospray process parameters resulted in surface coatings with rich morphologies that are revealed by SEM, Atomic Force Microscopy (AFM) and Confocal Raman Microscopy were employed to monitor the drug release process in situ, through which the mechanism of the drug-eluting process may be proposed. A Confocal Raman microscope fitted with underwater objective was used to image arbIBS∕drug films incubated in phosphate-buffered saline over 12h and at various film depths. Drug migrated from more concentrated areas into the surrounding polymer and toward the surface, beginning as early as 5min after placing the sample in buffer and continuing throughout the 12h period. High drug levels remained in the more concentrated areas at the end of incubation, suggesting the potential for prolonged release. SEM and AFM images taken from samples post incubation showed the appearance of nanoscale pores ∼100nm in diameter in areas corresponding in size and distribution to the Confocal Raman planar image areas of increased drug concentration. Confocal Raman microscopy offers a powerful new technique for demonstrating real-time drug release from therapeutic medical device coatings.

scholarly journals Label-Free Live-Cell Imaging with Confocal Raman Microscopy

2012 ◽  
Vol 102 (2) ◽  
pp. 360-368 ◽  
Author(s):  
Katharina Klein ◽  
Alexander M. Gigler ◽  
Thomas Aschenbrenner ◽  
Roberto Monetti ◽  
Wolfram Bunk ◽  
...  
Keyword(s):  
Live Cell Imaging ◽  
Cell Imaging ◽  
Raman Microscopy ◽  
Live Cell ◽  
Confocal Raman Microscopy ◽  
Label Free ◽  
Confocal Raman

Confocal Raman microscopy

2017 ◽  
pp. 65-83
Author(s):  
M. Gomez-Lazaro ◽  
A. Freitas ◽  
C.C. Ribeiro
Keyword(s):  
Raman Microscopy ◽  
Confocal Raman Microscopy ◽  
Confocal Raman
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