Controlled Drug Release from Biodegradable Shape-Memory Polymers

AB‐polymer Networks with Cooligoester and Poly(n‐butyl acrylate) Segments as a Multifunctional Matrix for Controlled Drug Release

“…Drug loading by swelling is a commonly used approach to load covalent SMP networks with drugs 34. It was hypothesized that changing the polymer hydrophilicity by introducing more hydrophilic glycolide groups in the polymer backbone may alter the drug loading for drugs of different hydrophilicity/hydrophobicity.…”

Shape-Memory Polymers as Drug Carriers—A Multifunctional System

“…In order to transfer SMPs as drug carriers into pharmaceutical sciences, an evaluation strategy was required that conceptually and methodologically addresses i) the impact of a physiological environment on the SME in order to determine water effects, like plasticization, but also the impact of ions, proteins, and other relevant physiological substances, ii) drug loading methods, which are suitable for both the respective polymeric material and drug, iii) the absence of drug effects on SMP functionality for independence of functionalities in a multifunctional device, and iv) under relevant conditions, drug release and SMP biodegradation behavior for assessing long-term suitability as biofunctional implant (6,7). For the aforementioned biodegradable, drug-loaded SMPs, independence of the different functionalities could be realized in most cases, particularly when drugs were incorporated as drug aggregates and did not closely interact with the switching domains of the SMP.…”

Shape-memory polymers as a technology platform for biomedical applications

“…In order to fully explore potential applications of SMPs in the biomedical field, controlled drug-release capability of SMP matrices has recently been studied [46,131,132]. As reviewed in detail [133], drug release rates over weeks or months could be established in some cases in these first studies, depending on the drug physicochemical properties and the network architecture. This has led to multifunctional materials for biomedical applications that combine biodegradability, controlled drug release and shape-memory capability.…”

“…The morphology of thermosensitive SMP materials, being either amorphous or semi-crystalline, could have a large impact, for example, on loading levels by the swelling technique, since drug incorporation is not expected to occur in the crystalline phase. Besides being capable of drug loading in the entire matrix, amorphous covalent SMP networks might advantageously show a more homogeneous biodegradation, slower changes of mechanical properties during degradation and an easier adjustment of degradation, and possibly of drug release rates, by changing the co-monomer ratios in the network precursors [133]. However, a possibly broader temperature interval of thermal transition or a potential drug-induced plasticization of the SMP and, as a consequence of this, alterations of the switching temperature, might be potential drawbacks of amorphous SMP networks.…”