Development of resorbable “Springs” for surgery

Abstract

The demand for replicating the functionality of conventional stainless steel springs with degradable and biocompatible materials has led to the exploration of alternative methods. Current trends focus on understanding the genetic and cellular causes of craniosynostosis rather than its treatment. Nonetheless, research has investigated gelatin scaffolds supporting suture regeneration with mesenchymal stem cells, protein-releasing Titania nanotubular implants that inhibit bone formation, and a bioabsorbable material blend of poly(lactic-co-glycolic acid) (PLGA) and polyisoprene (PI). Furthermore, advancements in 3D printing technology now enable the production of implantable objects, sparking interest in printing cranial spring implants, particularly for addressing sagittal craniosynostosis. Polylactic acid (PLA) was 3D printed, mechanical strength tested using force strain measurements and degradation was followed using PBS. PLGA/PI blends were prepared according to the suggested method, miscibilty and degradation in PBS at pH 7.4 and 5 were tested. Printed PLA samples with different filling patterns demonstrated high load-bearing capacity, averaging 2109 N, which scales to 527 N for implant size, surpassing the 8 N threshold of stainless steel springs. After one month, PLA showed no significant degradation, suggesting that this material lasts longer than the expected 4-6 months. A literature review was also conducted to assess existing methods and future directions in the field. This review provided valuable context for understanding current practices and emerging trends. Research into alternative materials led to the discovery of a promising PLGA/PI blend that had already been tested in rabbits [9]. The molding process and the immiscibility of the material became a major limitation for its use as a potential implant, even tough its degradation process seems promising.