A drug-loaded amphiphilic polymer/poly(L-lactide) shape-memory system

Biodegradable shape-memory polymers (SMPs) which are functional materials with applicability for medicine devices are designed to acquire their therapeutically relevant shape and drug release after implantation. In the work, an amphiphilic polymer (PVAD) is synthesized by using polytetrahydrofuran (PTMG), vinyl acetate (VAc), acrylic acid (AA), tetramethyltetravinylcyclotetrasiloxane (D-4(vi)) as raw materials. PVAD encapsulating hydro-philic drug as switching phase and poly(L-lactide) (PLLA) as fixing matrix construct an SM system with the characteristic of reservoir-matrix drug release. The shape recovery ratio (Rr) of medicated PVAD/PLLA reaches 99 % by heat-water stimulation. The effects of release temperature and SM on drug release are investigated. With the release temperature increasing, the medicated PVAD/PLLA accelerates drug release and shows burst release initially, while the drug release for the medicated PLLA changes slightly. The drug release rate goes up after 3 rounds of SM. The mechanism of SM system controlling drug release is put forward based on structural changes. The yield strength and elongation at break of medicated PVAD/PLLA are 29.8 MPa and 44.6 %, respectively. It opens up new perspectives for drug carrier matrices in Pharmaceutical Sciences.

Automated summary

This study focuses on the biodegradable shape-memory polymers (SMPs) for medical devices. The synthesized amphiphilic polymer (PVAD) encapsulates drug and forms an SM system with poly(L-lactide) (PLLA) as matrix. The drug release rate and mechanism can be controlled by adjusting the release temperature and shape memory (SM). This research opens up new possibilities for drug carrier matrices in Pharmaceutical Sciences.