Related Experiment Video
Updated: Jun 17, 2026
09:13
Implementation of a Nonlinear Microscope Based on Stimulated Raman Scattering
Published on: July 6, 2019
Application of Raman microscopy to biodegradable double-walled microspheres
Effendi Widjaja1, Wei Li Lee, Say Chye Joachim Loo
1Process Science and Modeling, Institute of Chemical and Engineering Sciences, Agency for Science, Technology and Research (ASTAR), 1 Pesek Rd, Jurong Island, Singapore 627833. effendi_widjaja@ices.a-star.edu.sg
Analytical Chemistry
|December 19, 2009
Summary
Raman microscopy combined with BTEM analysis successfully identified major components and unexpected contaminants within biodegradable double-walled microspheres. This technique offers sensitive chemical and spatial characterization of microsphere composition.
Area of Science:
- Materials Science
- Analytical Chemistry
- Polymer Science
Background:
- Biodegradable microspheres are crucial for drug delivery and tissue engineering.
- Characterizing the composition and spatial distribution of components within microspheres is essential for controlling their properties.
- Established techniques like SEM and optical microscopy provide morphological information but limited chemical detail.
Purpose of the Study:
- To characterize the chemical composition and spatial distribution of components in ternary-phase biodegradable double-walled microspheres (DWMS).
- To evaluate the efficacy of combining Raman microscopy with band-target entropy minimization (BTEM) for microsphere analysis.
- To identify both intended components and potential contaminants within the DWMS.
Main Methods:
- Fabrication of DWMS using poly(D,L-lactide-co-glycolide) (50:50) (PLGA), poly(L-lactide) (PLLA), and poly(epsilon-caprolactone) (PCL) via solvent evaporation.
- Raman mapping measurements on the cross-section of the fabricated DWMS.
- Application of the band-target entropy minimization (BTEM) algorithm to reconstruct pure component spectra from Raman data.
Main Results:
- Seven pure component spectra were successfully recovered using BTEM analysis.
- The primary components PLLA, PLGA 50:50, and PCL were identified.
- Minor components including polyglycolic acid (PGA, a PLGA decomposition product), dichloromethane (DCM, solvent), and unexpected contaminants copper-phthalocyanine blue and calcite were detected.
- Spatial distribution maps for all identified components were generated.
Conclusions:
- The combination of Raman microscopy and BTEM provides a sensitive and specific analytical method for characterizing DWMS.
- This technique reveals detailed chemical information and spatial distributions of components, including contaminants.
- This novel analytical approach complements existing methods for microsphere characterization.
