RESOURCES

Abstract
Psoriasis is a chronic inflammatory skin disease involving complex genetic, immune, and environmental interactions. Current in vitro models fail to fully replicate the human psoriatic microenvironment, while animal models are limited by species differences and ethical concerns, restricting their applicability in pathogenesis studies and drug screening. Here, we present a human-derived in vitro psoriasis model constructed via 3D bioprinting. By optimizing the bioink composition, we fabricated a full-thickness skin model with a vascularized dermal layer and a dense stratified epidermis. Cell viability in the bioprinted skin exceeded 90% after 7 d. The full-thickness skin exhibited a TEER value of ∼383 kΩ, reflecting native-like barrier integrity. Psoriatic features, including epidermal hyperplasia and upregulated inflammatory cytokines, were successfully induced through TNF-α and IL-22 stimulation. Structural and functional analyses confirmed that the model closely mimics the pathological hallmarks of psoriasis. Furthermore, drug testing showed that both tofacitinib and Danshensu effectively reduced IL-22 and TNF-α expression by more than 60%, while concurrently enhancing LOR expression by nearly 2-fold, reflecting improved epidermal differentiation. This study highlights the potential of 3D bioprinting in developing physiologically relevant skin disease models, providing a robust platform for psoriasis research and preclinical drug testing.

Abstract
The treatment of tumour-related bone defects should ideally combine bone regeneration with tumour treatment. Additive manufacturing (AM) could feasibly place functional bone-repair materials within composite materials with functional-grade structures, giving them bone repair and anti-tumour effects. Magnetothermal therapy is a promising non-invasive method of tumour treatment that has attracted increasing attention. In this study, we prepared novel hydrogel composite scaffolds of polyvinyl alcohol/sodium alginate/hydroxyapatite (PVA/SA/HA) at low temperature via AM. The scaffolds were loaded with various concentrations of magnetic graphene oxide (MGO) @Fe3O4 nanoparticles. The scaffolds were characterised by fourier transform infrared spectroscopy (FTIR), scanning electron microscope (SEM) and thermal gravimetric analysis (TGA), which showed that the scaffolds have good moulding qualities and strong hydrogen bonding between the MGO/PVA/SA/HA components. TGA analysis demonstrated the expected thermal stability of the MGO and scaffolds. Thermal effects can be adjusted by varying the contents of MGO and the strength of an external alternating magnetic field. The prepared MGO hydrogel composite scaffolds enhance biological functions and support bone mesenchymal stem cell differentiation in vitro. The scaffolds also show favourable anti-tumour characteristics with effective magnetothermal conversion in vivo.

Abstract
ABSTRACTArtificial skins have been used as skin substitutes for wound healing in the clinic, and as in vitro models for safety assessment in cosmetic and pharmaceutical industries. The three-dimensional (3D) bioprinting technique provides a promising strategy in the fabrication of artificial skins. Despite the technological advances, many challenges remain to be conquered, such as the complicated preparation conditions for bio-printed skin and the unavailability of stability and robustness of skin bioprinting. Here, we formulated a novel bio-ink composed of gelatin, sodium alginate and fibrinogen. By optimizing the ratio of components in the bio-ink, the design of the 3D model and the printing conditions, a fibroblasts-containing dermal layer construct was firstly fabricated, on the top of which laminin and keratinocytes were sequentially placed. Through air-liquid interface (ALI) culture by virtue of sterile wire mesh, a full-thickness skin tissue was thus prepared. HE and immunofluorescence staining showed that the bio-printed skin was not only morphologically representative of the human skin, but also expressed the specific markers related to epidermal differentiation and stratum corneum formation. The presented easy and robust preparation of full-thickness skin constructs provides a powerful tool for the establishment of artificial skins, holding critical academic significance and application value.