Jef Brebels

Despite decades of advancements in melt electrowriting (MEW) and electrospinning (ES), poly( ϵ -caprolactone) (PCL) remains the gold standard polymer for these techniques. Its widespread use is attributed to its processability in both melt and solution, thermal stability, and low melting temperature. MEW and ES enable the fabrication of micro- and nanofibrous scaffolds that can mimic the extracellular matrix of specific tissues. This makes them especially attractive for biomedical applications. However, PCL lacks key properties, e.g., elasticity and suitable biodegradation time, for soft tissue applications. We report for the first time the successful introduction of α -amino acid-based poly(ester amide)s (AAA-PEAs) for MEW processing. Additionally, ES outcomes have been improved compared to existing literature. These polymers were synthesized via polycondensation containing ester and amide functionalities, yielding high molar masses (>40 kg mol ⁻¹ ). L-alanine and L-phenylalanine were selected as α -amino acids, differing in hydrophobic side groups (methyl vs benzyl), resulting in distinct material properties. Both AAA-PEAs showed excellent ES processability, producing uniform fibers (1–3 μ m) without the need of adding PCL. Notably, only the phenylalanine-based PEA was so far processable by MEW, yielding smooth, uniform fibers (25–30 μ m) with no pulsing, fusing, or surface defects. As proof-of-concept, excellent stacking behavior up to 15 layers was achieved. Scaffolds exhibited enhanced ultimate tensile strength (13.70 ± 1.60 MPa) and accelerated biodegradation (72%–77% remaining mass after 16 weeks in phosphate buffered saline at 37 °C) compared to PCL. In vitro studies with MC3T3-E1 cells confirmed cytocompatibility. The above findings underscore the potential of AAA-PEAs as promising biomaterials for soft tissue biomedical applications.

The lower gastrointestinal (GI) tract is affected by a range of diseases, including colorectal cancer and inflammatory bowel disease, among others. Effective treatment of these conditions requires drug delivery systems (DDSs) capable of precise targeting. While pH‐ and enzyme‐sensitive DDSs are the most used, they often suffer from premature drug release and target specificity, limiting their efficacy. To address this challenge, researchers are exploring alternative triggers, such as reactive oxygen species (ROS), reduction‐oxidation (redox) and modified enzyme‐ and pH‐responsive systems, to enhance specificity and performance. This review highlights the latest advancements and current limitations in targeted drug delivery strategies for the lower GI tract, aiming to improve therapeutic outcomes and the quality of life for patients with intestinal disorders.

A flexor tendon injury is acquired fast and is common for athletes, construction workers, and military personnel among others, treated in the emergency department. However, the healing of injured flexor tendons is stretched over a long period of up to 12 weeks, therefore, remaining a significant clinical problem. Postoperative complications, arising after traditional tendon repair strategies, include adhesion and tendon scar tissue formation, insufficient mechanical strength for early active mobilization, and infections. Various researchers have tried to develop innovative strategies for developing a polymer-based construct that minimalizes these postoperative complications, yet none are routinely used in clinical practice. Understanding the role such constructs play in tendon repair should enable a more targeted approach. This review mainly describes the polymer-based constructs that show promising results in solving these complications, in the hope that one day these will be used as a routine practice in flexor tendon repair, increasing the well-being of the patients. In addition, the review also focuses on the incorporation of active compounds in these constructs, to provide an enhanced healing environment for the flexor tendon.