Biology subjects

Yilmaz, Y. O.

Publications and source records attributed to Yilmaz, Y. O..

4 recordsLinked to original sources

bioRxiv2026

Bioinstructive Orthogonally-crosslinked Ovoprotein Microgels for Modular Bioprinting

Bioprinting increasingly requires biomaterials that are not only printable, but structurally adaptive and biologically instructive. Here we establish an ovoprotein-derived microgel platform that couples intrinsic protein bioactivity with orthogonal interparticle photocrosslinking for modular bioprinting. Methacrylated ovoproteins yielded a photoresponsive protein-rich hydrogel matrix with retained proteomic complexity, tunable mechanics, and cell-regulatory biofunction. Endogenous tyrosine chemistry drove interparticle dityrosine coupling between ovoprotein microgels, producing cohesive, microporous, and intrinsically autofluorescent granular networks. The resulting systems displayed programmable rheology and broad compatibility across digital light processing, extrusion-based and aspiration-assisted bioprinting. Functionally, the ovoprotein microgel matrices attenuated sustained pro-inflammatory macrophage activation, promoted endothelial organization and host angiogenic invasion, and supported spheroid-mediated vascular morphogenesis with progressive sprouting, lumenization, branching and inosculation. It further enabled bioprinted osteogenic constructs with long-term maturation into bone-like mineralized tissues in vitro. These findings establish ovoprotein microgel-spheroid bioassembly as an adaptive, bioinstructive strategy for engineering vascularized and mineralized tissue constructs.

bioengineering↗

bioRxiv2025

Interparticle Crosslinked Ion-responsive Microgels for 3D and 4D (Bio)printing Applications

AbstractMicrogels offer unique advantages over bulk hydrogels due to their improved diffusion limits for oxygen and nutrients. Particularly, stimuli-responsive microgels with inherently bioactive and self-supporting properties emerge as highly promising biomaterials. This study unveils the development of interparticle-crosslinked, self-supporting, ion-responsive microgels tailored for 3D and 4D (bio)printing applications. A novel strategy was proposed to develop microgels that enabled interparticle crosslinking, eliminating the need for filler hydrogels and preserving essential microscale void spaces to support cell migration and vascularization. Additionally, these microgels possessed unique, ion-responsive shrinking behavior primarily by the Hofmeister effect, reversible upon the removal of the stimulus. Two types of microgels, spherical ({micro}S) and random-shaped ({micro}R), were fabricated, with {micro}R exhibiting superior mechanical properties and higher packing density. Fabricated microgel-based constructs supported angiogenesis with tunable vessel size based on interstitial void spaces while demonstrating excellent shear-thinning and self-healing properties and high print fidelity. Various bioprinting techniques were employed and validated using these microgels, including extrusion-based, embedded, intraembedded, and aspiration-assisted bioprinting, facilitating the biofabrication of scalable constructs. Multi-material 4D printing was achieved by combining ion-responsive microgels with non-responsive microgels, enabling programmable shape transformations upon exposure to ionic solutions. Utilizing 4D printing, complex, dynamic structures were generated such as coiling filaments, grippers, and folding sheets, providing a foundation for the development of advanced tissue models and devices for regenerative medicine and soft robotics, respectively.

bioengineering↗

bioRxiv2023

Nested biofabrication: Matryoshka-inspired Intra-embedded Bioprinting

Engineering functional tissues and organs remains a fundamental pursuit in biofabrication. However, the accurate constitution of complex shapes and internal anatomical features of specific organs, including their intricate blood vessels and nerves, remains a significant challenge. Inspired by the Matryoshka doll, we here introduce a new method called Intra-Embedded Bioprinting (IEB), building upon existing embedded bioprinting methods. We used a xanthan gum-based material, which served a dual role as both a bioprintable ink and a support bath, due to its unique shear-thinning and self-healing properties. We demonstrated IEBs capabilities in organ modelling, creating a miniaturized replica of a pancreas using a photocrosslinkable silicone composite. Further, a head phantom and a Matryoshka doll were 3D printed, exemplifying IEBs capability to manufacture intricate, nested structures. Towards the use case of IEB and employing innovative coupling strategy between extrusion-based and aspiration-assisted bioprinting, we developed a breast tumor model that included a central channel mimicking a blood vessel, with tumor spheroids bioprinted in proximity. Validation using a clinically-available chemotherapeutic drug illustrated its efficacy in reducing the tumor volume via perfusion over time. This method opens a new way of bioprinting enabling the creation of complex-shaped organs with internal anatomical features.

bioengineering↗

bioRxiv2023

A Versatile Photocrosslinkable Silicone Composite for 3D Printing Applications

Embedded printing has emerged as a valuable tool for fabricating complex structures and microfluidic devices. Currently, an ample of amount of research is going on to develop new materials to advance its capabilities and increase its potential applications. Here, we demonstrate a novel, transparent, 3D printable, photocrosslinkable, and tuneable silicone composite that can be utilized as a support bath or an extrudable ink for embedded printing. The proposed silicone composite can be tuned to achieve ideal rheological properties, such as optimal self-recovery and yield stress, for use in 3D printing. When used as a support bath, it facilitated the generation microfluidic devices with circular channels of diameter up to 30 {micro}m. To demonstrate its utility, flow focusing microfluidic devices were fabricated for generation of Janus microrods, which can be easily modified for multitude of applications. When used as an extrudable ink, 3D printing of complex-shaped micro- and macro-constructs were achieved with integrated electronics, which greatly extends its potential applications towards developing complex flexible parts for soft robotics and prosthetics. Further, its biocompatibility was tested with multiple cell types to validate its applicability for medical and tissue engineering use. Altogether, this material offers a myriad of potential applications in material and medical fields by providing a facile approach to develop complicated 3D structures and interconnected channels that can further advance microfluidics and soft-robotics research.

bioengineering↗