UMass Chan Medical School Faculty Publications


Modulating Mechanical and Shape-Memory Properties while Mitigating Degradation-Induced Inflammation of Polylactides by Pendant Aspirin Incorporation

UMMS Affiliation

Department of Orthopedics and Physical Rehabilitation; Department of Pathology

Publication Date


Document Type



Biomaterials | Biomedical Devices and Instrumentation | Materials Chemistry | Molecular, Cellular, and Tissue Engineering


Synergistically modulating mechanical properties and improving shape-memory performance while mitigating degradation-induced chronic inflammation of polylactide (PLA)-based implants for biomedical applications remain elusive. We test the hypothesis that copolymerizing aspirin-functionalized glycolide with d,l-lactide could enhance the thermal processing, toughness, and shape-memory efficiency of the copolymer while mitigating local inflammatory responses upon its degradation. The content of pendant aspirin was readily modulated by monomer feeds during ring-opening polymerization, and the copolymers with approximately 10% or less aspirin pendants exhibited gigapascal-tensile moduli at body temperature and significantly improved fracture toughness and energy dissipation that positively correlated with the aspirin pendant content. The copolymers also exhibited excellent thermal-healing and shape-memory efficacy, achieving a > 97% temporary shape fixing ratio at room temperature and facile shape recovery at 50-65 degrees C. These drastic improvements were attributed to the dynamic hydrophobic aggregations among aspirin pendants that strengthen glassy-state physical entanglement of PLA while readily dissociating under stress/thermal activation. When subcutaneously implanted, the copolymers mitigated degradation-induced inflammation due to concomitant hydrolytic release of aspirin without suppressing early acute inflammatory responses. The incorporation of aspirin pendants in PLA represents a straightforward and innovative strategy to enhance the toughness, shape-memory performance, and in vivo safety of this important class of thermoplastics for biomedical applications.


bone tissue engineering, inflammatory response, nonsteroidal anti-inflammatory drug, polylactic acid, shape memory, thermal healing

DOI of Published Version



Xu X, Zhang J, Filion TM, Akalin A, Song J. Modulating Mechanical and Shape-Memory Properties while Mitigating Degradation-Induced Inflammation of Polylactides by Pendant Aspirin Incorporation. ACS Appl Mater Interfaces. 2021 May 19;13(19):22271-22281. doi: 10.1021/acsami.1c06178. Epub 2021 May 6. PMID: 33956420; PMCID: PMC8151694. Link to article on publisher's site

Related Resources

Link to Article in PubMed

Journal/Book/Conference Title

ACS applied materials and interfaces

PubMed ID