Biology subjects

Cianciosi, A.

Publications and source records attributed to Cianciosi, A..

3 recordsLinked to original sources

bioRxiv2026

Optical Fiber-Assisted Bioprinting Enables Freeform Printing of Cell-Laden and Turbid Hydrogel Resins

Optical fiber-assisted printing (OFAP) was recently introduced as a straightforward light-based platform for the spatially controlled photopolymerization of hydrogel-based resins. Here, we extend this concept toward optical fiber-assisted bioprinting (OFAB) by processing cell-laden GelMA- and GelMA/PEGDA-based bioresins in a freeform embedded printing configuration. The system relies on a 405 nm LED-coupled optical fiber mounted on an automated 3D motion platform, enabling localized photocrosslinking directly within a resin bath. First, GelMA and GelMA/PEGDA formulations containing LAP and tartrazine were screened to evaluate the influence of light intensity, printing velocity, and material composition at the line width and curing depth. Single-line features with widths down to 70 {+/-} 20 {micro}m were obtained under optimized conditions, while more robust printing conditions yielded reproducible features in the range of 200-300 {micro}m. Photorheological and rotational rheology measurements confirmed that the formulations provide both thermoresponsive support during printing and photocrosslinked stability after processing. The incorporation of L929 cells demonstrated high cytocompatibility for GelMA and GelMA/PEGDA 6000 Da formulations, with viabilities above 90% after 7 days for selected printed constructs. Importantly, increasing the cell concentration up to 1 x 107 cells mL-1 did not prevent printing and reduced the extent of overcuring, suggesting that cell-induced turbidity can improve spatial confinement of polymerization in OFAB. Finally, a customized OFAB printer was developed to enable temperature-controlled processing and the fabrication of centimeter-scale 3D structures, including cell-laden constructs. Overall, this work establishes OFAB as an accessible and modular bioprinting strategy for cell-laden and optically turbid hydrogel resins, complementing existing light-based biofabrication approaches.

cell biology↗

bioRxiv2025

Integration of customizable 3D printed mixing printheads for controlled and tuneable material and stiffness gradient fabrication with high cell viability in extrusion-based bioprinting

The fabrication of native tissue-like structures with gradual transitions in material properties, cell types and growth factors remains a major challenge in biofabrication. Particularly the complex hierarchical organization, present in living tissues, has to be mimicked as close as possible for the created models to fulfil the desired function. However, the fabrication of gradual structures incorporating several materials ensuring high cell survival and subsequent unaffected tissue maturation is highly challenging. To get a step closer to the goal of generating tissue models containing controlled gradient structures, here we show a novel approach combining extrusion- based 3D bioprinting with static mixing, using self-designed Digital Light Processing (DLP) printed mixing units to fabricate defined gradual structures. Two passive mixing geometries, sinusoidal and obstacle-based, are designed and fabricated and benchmarked against commercially available static mixers. The mixing performance is assessed pixelwise using dyed alginate solutions that are extruded through the mixers using an adapted 3D printer equipped with cavity pumps. The obstacle structure exhibits the highest mixing rate compared to the sinusoidal design and commercially available static mixers. Beyond mixing efficiency, the biological compatibility of the systems is assessed by evaluating the viability of U87 and NIH3T3 cells after extrusion. Two distinct polymer solutions of differing viscosities, composed of allyl-modified gelatin (gelAGE), polyethylene glycol dithiol (PEG-2-SH), and Matrigel, are extruded through the static mixer, revealing significantly higher cell viability in the self-designed printheads compared to commercial mixers. Subsequently, graded structures mimicking the mechanical profile of native brain tissue are fabricated and mechanically characterized using nanoindentation, confirming the successful generation of continuous stiffness gradients. In summary, this study demonstrates that combining extrusion-based 3D printing with customizable mixing units enables the controlled fabrication of tissue-like gradient structures with enhanced mixing rates and cell viability. The design flexibility and rapid fabrication of DLP-printed printheads enable the adaptation to specific tissue requirements, providing a robust platform for future developments in biofabrication and tissue engineering. This work serves as foundation for the creation of increasingly complex and functional tissue models.

bioengineering↗

bioRxiv2024

Optical Fiber-Assisted Printing: A Platform Technology for Straightforward Photopolymer Resins Patterning and Freeform 3D Printing

Light-based 3D printing techniques represent powerful tools, enabling the precise fabrication of intricate objects with high resolution and control. An innovative addition to this set of printing techniques is Optical Fiber-Assisted Printing (OFAP) introduced in this manuscript. OFAP is a platform utilizing a LED-coupled optical fiber (LOF) which selectively crosslinks photopolymer resins. It allows on-the-fly change of parameters like light intensity and LOF velocity during fabrication, facilitating the creation of structures with progressive features and multi-material constructs layer-by-layer. An optimized formulation based on allyl-modified gelatin (gelAGE) with food dyes as photoabsorbers is introduced. Additionally, a novel gelatin-based biomaterial, alkyne-modified gelatin (gelGPE), featuring alkyne moieties, demonstrates near-visible light absorption thus fitting OFAP needs, paving the way for multifunctional hydrogels through thiol-yne click chemistry. Besides 2D patterning, OFAP is transferred to embedded 3D printing within a resin bath demonstrating the proof-of-concept as novel printing technology with potential applications in tissue engineering and biomimetic scaffold fabrication, offering rapid and precise freeform printing capabilities.

bioengineering↗