Department of Orthopedics and Physical Rehabilitation
Biomaterials | Biomechanics and Biotransport | Biomedical and Dental Materials | Biotechnology | Investigative Techniques | Macromolecular Substances | Materials Chemistry | Medical Biotechnology | Molecular, Cellular, and Tissue Engineering | Organic Chemicals | Orthopedics | Other Analytical, Diagnostic and Therapeutic Techniques and Equipment | Polymer Chemistry | Surgical Procedures, Operative | Tissues
Maintaining adequate or enhancing mechanical properties of shape memory polymers (SMPs) after shape recovery in an aqueous environment are greatly desired for biomedical applications of SMPs as self-fitting tissue scaffolds or minimally invasive surgical implants. Here we report stable temporary shape fixing and facile shape recovery of biodegradable triblock amphiphilic SMPs containing a poly(ethylene glycol) (PEG) center block and flanking poly(lactic acid) or poly(lactic-co-glycolic acid) blocks in warm water, accompanied by concomitant enhanced mechanical strengths. Differential scanning calorimetry (DSC), wide-angle X-ray diffraction (WXRD), and small-angle X-ray scattering (SAXS) analyses revealed that the unique stiffening of the amphiphilic SMPs upon hydration was due to hydration-driven microphase separation and PEG crystallization. We further demonstrated that the chemical composition of degradable blocks in these SMPs could be tailored to affect the persistence of hydration-induced stiffening upon subsequent dehydration. These properties combined open new horizons for these amphiphilic SMPs for smart weight-bearing in vivo applications (e.g., as self-fitting intervertebral discs). This study also provides a new material design strategy to strengthen polymers in aqueous environment in general.
amphiphilic biodegradable polymers, hydration-induced stiffening effect, minimal invasive surgery, shape memory, weight-bearing implantation
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This is an open access article published under an ACS AuthorChoice License, which permits copying and redistribution of the article or any adaptations for non-commercial purposes.
DOI of Published Version
ACS Appl Mater Interfaces. 2017 Feb 8;9(5):4450-4456.10.1021/acsami.6b14167. Epub 2017 Jan 26. Link to article on publisher's site
ACS applied materials and interfaces
Zhang B, DeBartolo JE, Song J. (2017). Shape Recovery with Concomitant Mechanical Strengthening of Amphiphilic Shape Memory Polymers in Warm Water. University of Massachusetts Medical School Faculty Publications. https://doi.org/10.1021/acsami.6b14167. Retrieved from https://escholarship.umassmed.edu/faculty_pubs/1267
Biomaterials Commons, Biomechanics and Biotransport Commons, Biomedical and Dental Materials Commons, Biotechnology Commons, Investigative Techniques Commons, Macromolecular Substances Commons, Materials Chemistry Commons, Medical Biotechnology Commons, Molecular, Cellular, and Tissue Engineering Commons, Organic Chemicals Commons, Orthopedics Commons, Other Analytical, Diagnostic and Therapeutic Techniques and Equipment Commons, Polymer Chemistry Commons, Surgical Procedures, Operative Commons, Tissues Commons