Chitosan-based hierarchical scaffolds crosslinked with genipin

Osteochondral defects present significant challenges for effective tissue regeneration due to the complex composition of bone and cartilage. To address this challenge, this study presents the fabrication of hierarchical scaffolds combining chitosan/β-tricalcium phosphate (β-TCP) to simulate a bone-like layer, interconnected with a silk fibroin layer to mimic cartilage, thus replicating the cartilage-like layer to mimic the native osteochondral tissue architecture. The scaffolds were produced by freeze-drying and then crosslinking with genipin. They have a crosslinking degree of up to 24%, which promotes a structural rearrangement and improved connection between the different layers. Micro-CT analysis demonstrated that the structures have distinct porosity values on their top layer (up to 84%), interface (up to 65%), and bottom layer (up to 77%) and are dependent on the concentration of β-tricalcium phosphate used. Both layers were confirmed to be clearly defined by the distribution of the components throughout the constructs, showing adequate mechanical properties for biomedical use. The scaffolds exhibited lower weight loss (up to 7%, 15 days) after enzymatic degradation due to the combined effects of genipin crosslinking and β-TCP incorporation. In vitro studies showed that the constructs supported ATDC5 chondrocyte-like cells and MC3T3 osteoblast-like cells in duo culture conditions, providing a suitable environment for cell adhesion and proliferation for up to 14 days. Overall, the physicochemical properties and biological results of the developed chitosan/β-tricalcium phosphate/silk fibroin bilayered scaffolds suggest that they may be potential candidates for osteochondral tissue strategies.This study was partially financed by the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior—Brasil (CAPES)—Finance Code 001 and Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq), PVE 407035/2013-3. This work is also financially supported by Portuguese FCT (PD/BD/135247/2017, SFRH/BPD/93697/2013, DL 57/2016/CP1377/CT0054 (https://doi.org/10.54499/DL57/2016/CP1377/CT0054), CEECINST/00018/2021), PhD programme in Advanced Therapies for Health (PATH) (PD/00169/2013), FCT R&D&I projects with references PTDC/BII-BIO/31570/2017, PTDC/CTM-CTM//29813/2017, and PTDC/CTM-BIO/4706/2014- (POCI-01-0145-FEDER-016716). The authors would like to thank the contributions to this research from the project “TERM RES Hub—Scientific Infrastructure for Tissue Engineering and Regenerative Medicine”, reference PINFRA/22190/2016 (Norte-01-0145-FEDER-022190), funded by the Portuguese National Science Foundation (FCT) in cooperation with the Northern Portugal Regional Coordination and Development Commission (CCDR-N), for providing relevant lab facilities, state-of-the-art equipment, and highly qualified human resources

Geografie relazionali nella storia del design

Con il tema delle “geografie relazionali” l'intenzione di questo numero è di valorizzare studi e ricerche che assumono approcci tipici delle scienze sociali per la comprensione e la spiegazione del design. Questo, infatti, oltre ad essere fatto di “cose”, strutture materializzate (come la nazione o la comunità), individui e meccanismi, è composto soprattutto di reti e fatti sociali: un insieme intricato e complesso di intersecazioni, rete di flussi e di relazioni..