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In vivo tissue responses to thermal-responsive shape memory polymer nanocomposites
Orthopedics and Physical Rehabilitation Publications and Presentations
  • Tera M. Filion, University of Massachusetts Medical School
  • Jianwen Xu, University of Massachusetts Medical School
  • Manju L. Prasad, Yale University School of Medicine
  • Jie Song, University of Massachusetts Medical School
UMMS Affiliation
Department of Cell Biology; Department of Orthopedics and Physical Rehabilitation
Publication Date
Document Type
Animals; Biocompatible Materials; Foreign-Body Reaction; Implants, Experimental; Male; Materials Testing; Molecular Structure; Nanocomposites; Polymers; Rats; Rats, Sprague-Dawley; *Temperature; Tissue Engineering; Tissue Scaffolds

To explore the safe use of thermal-responsive shape memory polymers (SMPs) as minimally invasive tissue scaffolds, we recently developed a class of biodegradable POSS-SMP nanocomposites exhibiting stable temporary shape fixing and facile shape recovery within a narrow window of physiological temperatures. The materials were covalently crosslinked from star-branched building blocks consisting a bioinert polyhedral oligomeric silsesquioxane (POSS) core and 8 degradable poly(D,L-lactide) (PLA) arms. Here we examine the degradation profiles and immunogenicity of POSS-SMPs as a function of the PLA arm lengths using a rat subcutaneous implantation model. We show that POSS-SMPs elicited a mild foreign body type immune response upon implantation. The degradation rates of POSS-SMPs, both in vitro and in vivo, inversely correlated with the length of the PLA chains within the crosslinked amorphous network. Upon in vivo degradation of POSS-SMPs, a second acute inflammatory response was elicited locally, and the inflammation was able to resolve over time without medical interventions. One year after the implantation of POSS-SMPs, no pathologic abnormalities were detected from the vital/scavenger organs examined. These minimally immunogenic and biodegradable SMPs are promising candidates for scaffold-assisted tissue repair where both facile surgical delivery and controlled degradation of the scaffold are desired for achieving optimal short-term and long-term clinical outcomes.

DOI of Published Version
Biomaterials. 2011 Feb;32(4):985-91. Epub 2010 Oct 30. Link to article on publisher's site
Related Resources
Link to Article in PubMed
PubMed ID
Citation Information
Tera M. Filion, Jianwen Xu, Manju L. Prasad and Jie Song. "In vivo tissue responses to thermal-responsive shape memory polymer nanocomposites" Vol. 32 Iss. 4 (2011) ISSN: 0142-9612 (Linking)
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