Fabrication of biodegradable drug-eluting scaffolds by two-photon polymerization

Two-photon polymerization (2PP) is a promising fabrication technology for three-dimensional microstructures. The high resolution of 2PP, with the capability to create features down to 100 nm, makes it an attractive tool for medical and biomedical applications. This is enabled by the availability of many biocompatible and biodegradable photoresists for 2PP. Consequently, the fabrication of scaffold structures by 2PP for tissue or cell engineering is a common practice. In this study, a novel approach to scaffold fabrication by 2PP is presented. The incorporation of drugs into a biodegradable photoresist is demonstrated to be a feasible method for passive drug-eluting scaffolds created by 2PP. The drug was mixed into the liquid photoresist prior to processing. Measurement of the drug-release was done by immersing the scaffolds in a water solution for a period of two weeks at 37 °C, with constant shaking in an incubator. The drug release was measured by taking extracts at defined time intervals and measuring the concentration using Inductively Coupled Plasma Mass Spectrometry (ICP-MS). As a result, an initial burst and a subsequent slowing increase of the drug concentration were detected.