Gel Casting as an Approach for Tissue Engineering of Multilayered Tubular Structures

What should be next in lifelong posterior hypospadias: Conclusions from the 2023 ERN eUROGEN and EJP-RD networking meeting

BACKGROUND

A congenital disease is for life. Posterior hypospadias, the severe form of hypospadias with a penoscrotal, scrotal, or perineal meatus, is a challenging condition with a major impact on lifelong quality of life.

AIM

Our network meeting is aimed to identify what is currently missing in the lifelong treatment of posterior hypospadias, to improve care, quality of life, and awareness for these patients.

METHODS

The network meeting "Lifelong Posterior Hypospadias" in Utrecht, The Netherlands was granted by the European Joint Programme on Rare Diseases-Networking Support Scheme. There was a combination of interactive sessions (hackathons) and lectures. This paper can be regarded as the last phase of the hackathon.

RESULTS

Surgery for hypospadias remains challenging and complications may occur until adulthood. Posterior hypospadias affects sexual function, fertility, and hormonal status. Transitional care from childhood into adulthood is currently insufficiently established. Patients should be more involved in defining desired treatment approach and outcome measures. For optimal outcome evaluation standardization of data collection and registration at European level is necessary. Tissue engineering may provide a solution to the shortage of healthy tissue in posterior hypospadias. For optimal results, cooperation between basic researchers from different centers, as well as involving clinicians and patients is necessary.

CONCLUSIONS

To improve outcomes for patients with posterior hypospadias, patient voices should be included and lifelong care by dedicated healthcare professionals guaranteed. Other requirements are joining forces at European level in uniform registration of outcome data and cooperation in basic research.

Probabilistic cell seeding and non-autofluorescent 3D-printed structures as scalable approach for multi-level co-culture modeling

To model complex biological tissue in vitro, a specific layout for the position and numbers of each cell type is necessary. Establishing such a layout requires manual cell placement in three dimensions (3D) with micrometric precision, which is complicated and time-consuming. Moreover, 3D printed materials used in compartmentalized microfluidic models are opaque or autofluorescent, hindering parallel optical readout and forcing serial characterization methods, such as patch-clamp probing. To address these limitations, we introduce a multi-level co-culture model realized using a parallel cell seeding strategy of human neurons and astrocytes on 3D structures printed with a commercially available non-autofluorescent resin at micrometer resolution. Using a two-step strategy based on probabilistic cell seeding, we demonstrate a human neuronal monoculture that forms networks on the 3D printed structure and can establish cell-projection contacts with an astrocytic-neuronal co-culture seeded on the glass substrate. The transparent and non-autofluorescent printed platform allows fluorescence-based immunocytochemistry and calcium imaging. This approach provides facile multi-level compartmentalization of different cell types and routes for pre-designed cell projection contacts, instrumental in studying complex tissue, such as the human brain.

Biofabrication of a Functional Tubular Construct from Tissue Spheroids Using Magnetoacoustic Levitational Directed Assembly

In traditional tissue engineering, synthetic or natural scaffolds are usually used as removable temporal support, which involves some biotechnology limitations. The concept of "scaffield" approach utilizing the physical fields instead of biomaterial scaffold has been proposed recently. In particular, a combination of intense magnetic and acoustic fields can enable rapid levitational bioassembly of complex-shaped 3D tissue constructs from tissue spheroids at low concentration of paramagnetic agent (gadolinium salt) in the medium. In the current study, the tissue spheroids from human bladder smooth muscle cells (myospheres) are used as building blocks for assembling the tubular 3D constructs. Levitational assembly is accomplished at low concentrations of gadolinium salts in the high magnetic field at 9.5 T. The biofabricated smooth muscle constructs demonstrate contraction after the addition of vasoconstrictive agent endothelin-1. Thus, hybrid magnetoacoustic levitational bioassembly is considered as a new technology platform in the emerging field of formative biofabrication. This novel technology of scaffold-free, nozzle-free, and label-free bioassembly opens a unique opportunity for rapid biofabrication of 3D tissue and organ constructs with complex geometry.