Developing a Tunable-Porosity, Fiber-Based Granular Hydrogel Bioink for 3D Printing; Analyzing Technological Momentum and Clinical Misconduct in the Macchiarini Synthetic Trachea Scandal 14 views

Thomas Ackleson – April 19th, 2026 – STS 4600 Socio-technical Synthesis: 3D Printed Biomaterials and Clinical Translation Ethics Introduction Biomaterial scaffolds are a core component of current regenerative medicine research. My technical capstone project sought to design and test a new biomaterial that satisfied current material shortcomings for use in 3D bioprinting applications. My STS research project explored how technological momentum can lead to the misuse of these biomaterials even with good intentions. This research provided insight to the importance of rigorous, honest science, particularly when powerful institutions and patient well-being are at play. Technical Report Summary The design proposed in my technical report filled an unmet need in regenerative medicine by combining two topographically-unique biomaterials to form a tunable, composite bioink. Traditional engineered tissue scaffolds often fail to balance necessary biological and mechanical properties for effective wound healing. Bulk hydrogels are biocompatible but typically lack the fibrous structure of native tissue; granular, spherical hydrogels allow for nutrient diffusion but are mechanically weak; and electrospun materials mimic the fibrous extracellular matrix but are difficult to scale. The composite bioink I designed addresses each of these weaknesses by combining electrospun hydrogel fibers with spherical gelatin microparticles. This material’s gelatin particles act as sacrificial thermal porogens; once a scaffold of this material is 3D printed and incubated at body temperature, the gelatin melts leaving behind an interconnected network of pores. The fiber hydrogels in the material undergo a shear stress in the 3D printing process that align them anisotropically like in native tissue. Subsequent crosslinking of this material system enhances the mechanical stability and biocompatibility of the material. STS Research Summary My STS research paper argues that the Paolo Macchiarini synthetic trachea scandal was not merely a case of individual scientific fraud, but rather a structural failure caused by technological momentum. Using this framework, I demonstrate how Macchiarini’s synthetic tissue scaffold evolved from a malleable project into an autonomous force that eventually overrode the ethical and scientific failsafes traditionally associated with translational medical research. I argue that Paolo Macchiarini, an Italian surgeon, was hired by the Karolinska Institute to fulfill their strategic need to regain institutional status and reputation. After losing critical licenses, the hospital recruited Macchiarini to establish a leading regenerative medicine center. This institutional desperation created a pro-innovation environment where standard vetting processes were bypassed in favor of recruiting a rising star in the field, despite numerous concerns about his past employment and personality. Early publications, which were later discovered to be fraudulent, described a successful proof-of-concept of Macchiarini’s synthetic trachea surgeries. The technical inertia these publications generated made it nearly impossible for external critics or whistleblowers to challenge the new technology, even as patients began to suffer and die behind the scenes – the ultimate cost of the scandal. Conclusion Working on the STS and technical research described above simultaneously has been an exercise of great value. Each project informed the direction of the other - my technical project gave me a deeper appreciation for the challenges associated with medical research, and studying Macchiarini encouraged me to reflect on the importance of rigorous and honest scientific work.

BS (Bachelor of Science)

Hydrogels; Tissue engineering; Biomaterials; 3D Bioprinting

School of Engineering and Applied Science Bachelor of Science in Biomedical Engineering Technical Advisor: Chris Highley STS Advisor: Benjamin Laugelli Technical Team Members: Manjiri Talegaonkar, Anna Young

English

All rights reserved by the author (no additional license for public reuse)

2026-05-04