Recent years have observed a significant increase in the use of degradable materials in medicine due to their minimal impact on the patient and broad range of applicability. The biodegradable polymer Polydioxanone (PDO) provides a good example of the use of such one polymer that can represent the aforementioned medical materials in the field of medicine, due to its high level of biocompatibility and interesting mechanical properties. PDO is used to produce absorbable medical devices such as sutures and stents, and is also suitable for the fabrication of certain orthopedic implants. Polydioxanone can be processed using the injection molding method due to its thermoplastic nature; this method allows for the precise and easily-controllable production of medical materials without the need for toxic additives. A number of small commercial polymer implants have recently been introduced onto the market based on this processing method. It is important to note that, to date, no relevant information on the molding of PDO is available either for the scientific or the general public, and no study has been published that describes the potential of the injection molding of PDO. Hence, we present our research on the basic technological and material parameters that allow for the processing of PDO using the laboratory microinjection molding method. In addition to determining the basic parameters of the process, the research also focused on the study of the structural and mechanical properties of samples based on the thermal conditions during processing. A technological frame work was successfully determined for the processing of PDO via the microinjection molding approach that allows for the production of samples with the required homogeneity, shape stability and surface quality in a laboratory scale. The research revealed that PDO is a polymer with a major share of crystalline phases, and that it is sensitive to the annealing temperature profile in the mold, which has the potential to impact the final crystalline structure, the fracture morphology and the mechanical properties.

Environmentally-friendly thermoplastic biodegradable polyesters such as polydioxanone (PDO) are becoming increasingly available and are attracting considerable interest in the medical field due to their favourable mechanical properties and degradation to low-toxicity monomers in vivo. These properties are of particular interest in terms of their use in the field of tailored medical implants produced by means of additive manufacturing via 3D printing applying the fused deposition modelling (FDM) technique, also known as fused filament fabrication (FFF). The increasing popularity of this technology in the biomedical community is due mainly to its versatility in terms of the processing approach, structural features and final design. Practically no comprehensive studies have been conducted to date on the 3D printing of polydioxanone. Given the very limited availability of this polymer at a level of quality that allows for its medical application in humans, the aim of this study was to test the use of a commonly available polydioxanone surgical monofilament for the study of its 3D printing potential. PDO comprises a highly crystalline polymer that is susceptible to shrinkage, warpage and adhesion problems. These issues were addressed in the study together with the determination of a range of other printing parameters related to the processing of PDO for FFF 3D printing purposes. The additively produced PDO models evinced similar mechanical properties to PDO samples produced via the classical injection molding technique. Moreover, no negative impact was detected of the printing conditions on the potential degradation of the biodegradable polymer. Thus, the aim to produce PDO models with a high level of printing quality at the microscopic and macroscopic levels with real potential for use in medical applications was achieved.