1. Razvoj novih metod izdelave in karakterizacije mikrožilja v in vitro modelihJernej Vajda, 2025, doktorska disertacija Opis: Doktorska disertacija obravnava optimizacijo postopkov, materialov in analiznih metod v tkivnem inženirstvu mikrožilja z multidisciplinarnim pristopom, ki poleg uveljavljenih bioloških in kemijskih metod vključuje tudi računalniške simulacije, mehanske teste in nanotomografijo. V okviru raziskovalnega dela smo optimizirali linearnost ekstruzije mehanskih ekstruzijskih 3D tiskalnikov, s čimer smo dosegli boljše in bolj ponovljive rezultate 3D (bio)tiska vzorcev. Pri natisnjenih vzorcih smo primerjali uporabo CaCl2 in SrCl₂ kot ionskih zamreževalcev, pri čemer se je izkazalo, da je uporaba SrCl2 ob primerljivi celični metabolni aktivnosti izboljšala mehanske lastnosti materialov, kombinacija Sr²⁺ in Ca²⁺ pa bi lahko omogočala dodatno prilagoditev mehanskih lastnosti materialov. Uporaba Sr²⁺ hkrati zmanjša tudi vpliv kalcijevih ionov na signalizacijo celic, kar je ključno za simuliranje biološkega okolja. Na drugi strani smo s simulacijami računalniške dinamike tekočin določili mejne pogoje za razvoj peristaltične črpalke,
s katero smo eksperimentalno ovrednotili vpliv strižnih napetosti na endotelijske celice in validirali simulirane rezultate. Ločeno smo na endotelijskih celicah iz različnih virov in na podpornih celicah – kožnih fibroblastih – preiskovali lastnosti materialov in njihov vpliv na viabilnost, ohranitev celičnega fenotipa in funkcionalnosti ter celokupno metabolno aktivnost. Rezultati študij potrjujejo, da je z natančno optimizacijo procesov in materialov mogoče izboljšati funkcionalnost tkivnih in vitro modelov, kar odpira nove možnosti za napredek v tkivnem inženirstvu in regenerativni medicini.
Ključne besede: mikrožilje, in vitro model, 3D tisk, računalniška dinamika tekočin, nanotomografija
Objavljeno v DKUM: 04.07.2025; Ogledov: 0; Prenosov: 4
 Celotno besedilo (52,49 MB) |
2. Microvascular tissue engineering : a reviewJernej Vajda, Marko Milojević, Uroš Maver, Boštjan Vihar, 2021, pregledni znanstveni članek Opis: Tissue engineering and regenerative medicine have come a long way in recent decades, but the lack of functioning vasculature is still a major obstacle preventing the development of thicker, physiologically relevant tissue constructs. A large part of this obstacle lies in the development of the vessels on a microscale%the microvasculature%that are crucial for oxygen and nutrient delivery. In this review, we present the state of the art in the field of microvascular tissue engineering and demonstrate the challenges for future research in various sections of the field. Finally, we illustrate the potential strategies for addressing some of those challenges.
Ključne besede: regenerative medicine, tissue engineering, vascularization, biomaterials, microvascularization, coculture, gradients
Objavljeno v DKUM: 18.10.2024; Ogledov: 0; Prenosov: 6
Celotno besedilo (6,81 MB)
Gradivo ima več datotek! Več... |
3. In vitro disease models of the endocrine pancreasMarko Milojević, Jan Rožanc, Jernej Vajda, Laura Činč Ćurić, Eva Paradiž, Andraž Stožer, Uroš Maver, Boštjan Vihar, 2021, pregledni znanstveni članek Opis: The ethical constraints and shortcomings of animal models, combined with the demand to study disease pathogenesis under controlled conditions, are giving rise to a new field at the interface of tissue engineering and pathophysiology, which focuses on the development of in vitro models of disease. In vitro models are defined as synthetic experimental systems that contain living human cells and mimic tissue- and organ-level physiology in vitro by taking advantage of recent advances in tissue engineering and microfabrication. This review provides an overview of in vitro models and focuses specifically on in vitro disease models of the endocrine pancreas and diabetes. First, we briefly review the anatomy, physiology, and pathophysiology of the human pancreas, with an emphasis on islets of Langerhans and beta cell dysfunction. We then discuss different types of in vitro models and fundamental elements that should be considered when developing an in vitro disease model. Finally, we review the current state and breakthroughs in the field of pancreatic in vitro models and conclude with some challenges that need to be addressed in the future development of in vitro models.
Ključne besede: in vitro disease models, pancreas, islet of Langerhans, 3D cell culture, scaffolds, acute tissue slices
Objavljeno v DKUM: 01.10.2024; Ogledov: 0; Prenosov: 422
Celotno besedilo (4,42 MB)
Gradivo ima več datotek! Več... |
4. Algorithmic linearization improves Syringe-based extrusion in elastic systems using Hydrogel-based materialsJernej Vajda, Luka Banović, Mihael Miško, Igor Drstvenšek, Marko Milojević, Uroš Maver, Boštjan Vihar, 2023, izvirni znanstveni članek Opis: Accuracy and precision are essential in extrusion-based material handling such as three-dimensional (3D) bioprinting. However, the elasticity of components, backlash, variability of nozzle and cartridge shapes, etc. can lead to unpredictable printing results, which is further complicated by the wide range of rheologically diverse materials and complex sample designs. To address this issue, we present an algorithmic approach to compensate for the discrepancies between piston motion and material extrusion in syringe-based extrusion systems. This approach relies on cyclical, iterative optimization through rapid piston movements, which are adjusted based on extrusion analysis. In this work we establish a general theoretical framework for extrusion and link the rheological properties of prepared hydrogels with shear rates in a typical bioprinting process. The determined properties are compared with the success of the developed algorithm to modify machine instructions for precise material deposition of short, interrupted lines, as well as multi-layered scaffold structures. Overall, our approach provides a means of improving the accuracy and precision of complex extrusion-based bioprinting systems, without prior knowledge of set-up or material properties, making it highly versatile and suitable for a wide range of applications, particularly when the combined set-up and material properties are too complex for solely predictive approaches.
Ključne besede: 3D bioprinting, syringe extrusion, optimization, algorithm
Objavljeno v DKUM: 21.04.2023; Ogledov: 684; Prenosov: 113
Celotno besedilo (3,38 MB)
Gradivo ima več datotek! Več... |
