Speaker
Description
Introduction:
Internal cellularization of thick tissue scaffolds remains a central challenge in tissue engineering, often requiring complex and costly technologies. In this study, we developed a cost-effective chaotic bioprinting strategy to fabricate compartmentalized hydrogel filaments that simultaneously provide physical cues (hollow microchannels for enhanced mass transport) and chemical cues (sustained ion release from mesoporous bioactive glass [BG] nanoparticles) to support angiogenesis and cellularization.
Methods:
We employed multimaterial chaotic bioprinting, leveraging static mixer-induced flows to co-extrude three distinct hydrogel inks: (1) a soft, cell-friendly ink that naturally contains cell adhesion motifs; (2) a reinforcing ink based on high-viscosity alginate and loaded with BG nanoparticles, providing chemical cues; and (3) a sacrificial ink designed to generate internal void channels. Using these materials, we fabricated four types of hydrogel filaments: (a) solid filaments without internal voids (Sld); (b) filaments with aligned hollow channels (Ch); (c) solid filaments with BG nanoparticles (Sld+BG); and (d) channel-containing filaments with BG nanoparticles (Ch+BG) (Figure 1A). Structural features were characterized via fluorescence microscopy, while physicochemical properties were assessed through swelling assays, tensile testing, and X-ray diffraction. BG incorporation and ion release were evaluated using energy-dispersive spectroscopy (EDS). To assess in vivo-like behavior, printed scaffolds were cultured ex-ovo on the chorioallantoic membrane (CAM) of chick embryos to evaluate vascularization and tissue colonization.
Results:
The hydrogel filaments exhibited structural integrity, enhanced mechanical modulus, and controlled ion diffusion. Filaments containing both void channels and BG nanoparticles showed superior nutrient transport and supported cell migration and adhesion. CAM assays indicated increased cellularization and signs of neovascularization compared to non-structured bulk controls.
Discussion:
Our results demonstrate that chaotic bioprinting enables the integration of functional spatial microarchitecture with bioactive chemical cues within a single filament. The use of void microchannels improves diffusion and supports tissue-like organization, while BG nanoparticles promote cell recruitment (Figure 1B). This combined approach enhanced scaffold performance across mechanical, transport, and biological dimensions.
Conclusion:
This work presents a scalable, multimaterial bioprinting platform that unites prevascularization and biochemical activation for the fabrication of next-generation tissue scaffolds. Applications include wound healing, in vitro tissue models, and small-scale transplantation.
References:
Bolívar-Monsalve, E. J. et al. Continuous chaotic bioprinting of skeletal muscle-like constructs. Bioprinting 21, (2021).
Bolívar-Monsalve, E. J. et al. One-Step Bioprinting of Multi-Channel Hydrogel Filaments Using Chaotic Advection: Fabrication of Pre-Vascularized Muscle-Like Tissues. Adv Healthc Mater 11, (2022).
Ceballos-González, C. F. et al. Plug-and-Play Multimaterial Chaotic Printing/Bioprinting to Produce Radial and Axial Micropatterns in Hydrogel Filaments. Adv Mater Technol 8, (2023).
64057828328