Shape‐memory bioresorbable terpolymer composite with antirestenotic drug

Abstract

Shape-memory polymers (SMPs) that combine shape-memory, biodegradability, and controlled drug release properties are very promising for medical and pharmaceutical application. Moreover, incorporation of antirestenotic drug into SMP biodegradable stent seems to be an interesting solution because of possibility to combine the mechanical support that provides stent and also drug elution. The aim of our study was to analyze the effect of incorporation of sirolimus into poly(L-lactide-co-glycolide-co-trimethylene carbonate) on physicochemical and mechanical properties, degradation, and shape-memory effect of the terpolymer. For this purpose, sirolimus was incorporated into the terpolymer by injection molding method. It has been demonstrated that drug-free terpolymer after injection molding characterized insignificant changes in terpolymer composition. Degradation of materials during processing was not observed. Incorporation of drug molecules did not change shape-memory properties of terpolymer.1 H-and 13 C-NMR spectra of poly(lactide-co-glycolide-co-trimethylene carbonate) confirmed that changes during degradation were similar for terpolymer and terpolymer with sirolimus. Sustained and regular release of sirolimus was observed. The developed material presents potential for biomedical and pharmaceutical applications.

Shape-Memory Terpolymer Rods with 17-β-estradiol for the Treatment of Neurodegenerative Diseases: an In Vitro and In Vivo Study

“…This may also favor a linear release of E2 (Table I). The listed changes are typical of the degradation processes of aliphatic polyesters (18,36). However, the observed derogations in release profile of E2 between 57 and 92 days might result from significant changes in T g , M n , WL and WU in this period (Table I).…”

“…In this work, implantable rods were developed based on an innovative bioresorbable terpolymer poly(L-lactide-co-glycolide-trimethylenecarbonate) P(L-LA:GA:TMC) with shape-memory (17,18) and synthesized with the use of a low-toxic initiator of polymerization, i.e. zirconium (IV) acetylacetonate (Zr(Acac) 4 ) (19).…”

“…Zr(Acac) 4 seems to be a promising alternative, and its low biological toxicity as compared to stannous octanoate has been confirmed (21). Copolymers and terpolymers obtained with this initiator were characterized in detail in a previous study (18,22). Moreover, the Zr(Acac) 4 initiator makes it possible to achieve a similar chain microstructure of polymeric materials based on lactidyl, glicolidyl, carbonate and caproyl monomers such as stannous octanoate and allows to obtain high-molecular-weight copolymers with good mechanical properties (23,24).…”

“…However, other solutions besides stents are also possible. In this work, a thermally sensitive P(L-LA:GA:TMC) terpolymer was used which is able to move from a temporary fixed shape to the original permanent shape upon exposure to a thermal stimulus (18). Therefore, optimization of treatment of neurodegradative diseases by reducing invasiveness and the burst effect may be guaranteed.…”

Responsive Biomaterials: Advances in Materials Based on Shape‐Memory Polymers

“…[11] Critically, responsive stents that prevent or deter restenosis (narrowing of blood vessels after surgical interventions) are a significant focus of SMP technology. Examples of SMP-derived stents include temperature-responsive devices that elute sirolimus (a drug with antiproliferative and immune suppressive properties), [12] or paclitaxel (an antiproliferative that limits the growth of neointima) [13] over a period of weeks. Interestingly, temperature-responsive SMP-based stents that elute curcumin (an antiproliferative and anticoagulant) and mitomycin C (an inhibitor of smooth muscle cell proliferation and neointima formation) over 14 and 60 days, respectively, were shown to simultaneously inhibit early thrombosis and long term smooth muscle cell proliferation, which are promising for the prevention of restenosis.…”