Biodegradable core-shell materials via RAFT and ROP: Characterization and comparison of hyperbranched and microgel particles

Zheng, Yu, Turner, William, Zong, Mengmeng, Irvine, Derek J., Howdle, Steven M. and Thurecht, Kristofer J. (2011) Biodegradable core-shell materials via RAFT and ROP: Characterization and comparison of hyperbranched and microgel particles. Macromolecules, 44 6: 1347-1354. doi:10.1021/ma1027092


Author Zheng, Yu
Turner, William
Zong, Mengmeng
Irvine, Derek J.
Howdle, Steven M.
Thurecht, Kristofer J.
Title Biodegradable core-shell materials via RAFT and ROP: Characterization and comparison of hyperbranched and microgel particles
Journal name Macromolecules   Check publisher's open access policy
ISSN 0024-9297
1520-5835
Publication date 2011-03-22
Year available 2011
Sub-type Article (original research)
DOI 10.1021/ma1027092
Open Access Status DOI
Volume 44
Issue 6
Start page 1347
End page 1354
Total pages 8
Place of publication Washington, DC, United States
Publisher American Chemical Society
Language eng
Abstract Two methodologies for synthesizing novel, degradable, core cross linked copolymer particles were investigated and the molecular properties of the resultant polymers were compared. The. first approach was to synthesize hyperbranched poly(epsilon-caprolactone-co-N,N-dimethylamino-2-ethyl methacrylate (PCL-co-PDMAEMA) by combining metal-catalyzed ring-opening polymerization (ROP) of epsilon-caprolactone (epsilon-CL) and reversible addition-fragmentation chain transfer polymerization (RAFT) of N,N-dimethylamino-2-ethyl methacrylate. First, the hyperbranched core was prepared via ROP copolymerization of epsilon-CL and branching agent 4,4-bioxepanyl-7,7-dione (BOD). This polymerization was initiated using the hydroxyl moiety of the bifunctional initiator 4-cyano-1-hydroxypent-4-yl dithiobenzoate (ACP-RAFT) which resulted in reactive pendent RAFT groups located in the polymer chains. The hyperbranched structure was confirmed by GPC-MALLS and NMR. Subsequent chain extension of this hyperbranched macromolecule with DMAEMA using RAFT chemistry yielded water-soluble nanoparticles. The second method involved the synthesis of core-cross-linked-shell particles (CCS) by the arm-first route. Linear arms of DMAEMA were synthesized using ACP-RAFT and subsequently used as macroinitiator for the ROP of epsilon-CL and BOD to form a degradable microgel that was water-soluble. Once again, molecular structure was analyzed by H-1 NMR, C-13 NMR, and GPC and molecular size by TEM. Finally, GPC-MALLS was used to qualitatively investigate the different cross-link densities of the degradable core by the two different methodologies. Thus, we demonstrate two synthetic approaches for constructing water-soluble, degradable core-shell nanoparticles that exhibit varying degrees of cross-linking by combining RAFT and ROP.
Formatted abstract
Two methodologies for synthesizing novel, degradable, core cross-linked copolymer particles were investigated and the molecular properties of the resultant polymers were compared. The first approach was to synthesize hyperbranched poly(ε-caprolactone-co-N,N-dimethylamino-2-ethyl methacrylate (PCL-co-PDMAEMA) by combining metal-catalyzed ring-opening polymerization (ROP) of ε-caprolactone (ε-CL) and reversible addition−fragmentation chain transfer polymerization (RAFT) of N,N-dimethylamino-2-ethyl methacrylate. First, the hyperbranched core was prepared via ROP copolymerization of ε-CL and branching agent 4,4-bioxepanyl-7,7-dione (BOD). This polymerization was initiated using the hydroxyl moiety of the bifunctional initiator 4-cyano-1-hydroxypent-4-yl dithiobenzoate (ACP-RAFT) which resulted in reactive pendent RAFT groups located on the polymer chains. The hyperbranched structure was confirmed by GPC-MALLS and NMR. Subsequent chain extension of this hyperbranched macromolecule with DMAEMA using RAFT chemistry yielded water-soluble nanoparticles. The second method involved the synthesis of core-cross-linked-shell particles (CCS) by the arm-first route. Linear arms of DMAEMA were synthesized using ACP-RAFT and subsequently used as macroinitiator for the ROP of ε-CL and BOD to form a degradable microgel that was water-soluble. Once again, molecular structure was analyzed by 1H NMR, 13C NMR, and GPC and molecular size by TEM. Finally, GPC-MALLS was used to qualitatively investigate the different cross-link densities of the degradable core by the two different methodologies. Thus, we demonstrate two synthetic approaches for constructing water-soluble, degradable core−shell nanoparticles that exhibit varying degrees of cross-linking by combining RAFT and ROP.
Keyword Polymer Science
Polymer Science
POLYMER SCIENCE
Q-Index Code C1
Q-Index Status Confirmed Code
Grant ID DP0880032
Institutional Status UQ

Document type: Journal Article
Sub-type: Article (original research)
Collections: Official 2012 Collection
Centre for Advanced Imaging Publications
 
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Created: Wed, 25 Jan 2012, 21:24:37 EST by Sandrine Ducrot on behalf of Centre for Advanced Imaging