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Muniz, R. S.

Publications and source records attributed to Muniz, R. S..

2 recordsLinked to original sources

3D Hybrid Bioprinting for Complex Multi-Tissue Engineering

3D bioprinting has revolutionized tissue engineering, enabling intricate, physiologically relevant constructs unattainable with conventional techniques, yet it remains limited in integrating soft and rigid multifunctional components for complex multi-tissue applications. In this study, we introduce a 3D hybrid bioprinting approach implementing the Hybprinter platform, which integrates multiple 3D printing modules under optimized conditions for a continuous bioprinting process with multiple soft and hard biomaterials. This approach demonstrates robust biocompatibility and broad tissue engineering potential for modeling and therapeutic applications. The capacity to fabricate multi-hydrogel hybrid constructs is illustrated by representative examples highlighting vascularization, multifunctionality, mechanical robustness, and implant suturability. Notably, compared with commonly fabricated hydrogel-only constructs, the resulting hybrid constructs achieve over a 1000-fold increase in mechanical strength, and demonstrated enhanced osteogenic differentiation, underscoring their suitability for load-bearing musculoskeletal and orthopedic tissue engineering. Additionally, cell-laden hydrogel constructs demonstrated robust chondrogenic differentiation, highlighting the capacity for lineage-specific tissue development in vitro. Beyond these outcomes, the presented hybrid bioprinting approach integrates essential tissue engineering attributes that unites mechanical robustness and suturable capacity with multi-material integration, gradient property design, incorporation of bioactive agents, and support for multi-cell loading. This versatile platform advances complex tissue engineering and holds promise for patient specific, organ-on-demand applications.

bioengineering↗

Revealing spatio-temporal dynamics with long-term trypanosomatid live-cell imaging

Trypanosoma brucei, the causative agent of human African trypanosomiasis, employs a flagellum for dissemination within the parasites mammalian and insect hosts. T. brucei cells are highly motile in culture and must be able to move in all three dimensions for reliable cell division. These characteristics have made long-term microscopic imaging of live T. brucei cells challenging, which has limited our understanding of a variety of important cell-cycle events. To address this issue, we have devised an imaging approach that confines cells to small volumes that can be imaged continuously for up to 24 h. This system employs cast agarose microwells generated using a PDMS stamp that can be made with different dimensions to maximize cell viability and imaging quality. Using this approach, we have imaged individual T. brucei through multiple rounds of cell division with high spatial and temporal resolution. We have employed this method to study the differential rate of T. brucei daughter cell division and show that the approach is compatible with loss-of-function experiments such as small molecule inhibition and RNAi. We have also developed a strategy that employs in-well "sentinel" cells to monitor potential toxicity due to imaging. This live-cell imaging method will provide a novel avenue for studying a wide variety of cellular events in trypanosomatids that have previously been inaccessible. ImportanceTrypanosoma brucei causes severe diseases that affect humans and livestock in Sub-Saharan Africa. Efficient strategies for manipulating the T. brucei genome have provided a wealth of information about protein localization and function in diverse cellular processes. However, employing live-cell imaging for phenotypic analysis in T. brucei remains a significant challenge because immobilization of this highly motile parasite rapidly leads to morphologic defects and cell death. While fixed-cell imaging can provide snapshots of cellular events, it cannot provide the direct causal link or precise timing of events that comes from watching a living cell change over time. Our strategy using agarose microwells now allows long-term live cell T. brucei imaging with a simple apparatus that can be adapted for a wide range of experimental conditions.

microbiology↗