The use of digital twins in tissue engineering (TE) applications is of paramount importance to reduce the number of in vitro and in vivo tests. To pursue this aim, a novel multimodal bioreactor is developed, combining 3D design with numerical stimulation. This approach will facilitate the reproducibility between studies and the platforms optimisation (physical and digital) to enhance TE. The new bioreactor was specifically designed to be additive manufactured, which could not be reproduced with conventional techniques. Specifically, the design suggested allows the application of dual stimulation (electrical and mechanical) of a scaffold cell culture. For the selection of the most appropriate material for bioreactor manufacturing several materials were assessed for their cytotoxicity. Numerical modelling methods were then applied to the new bioreactor using one of the most appropriate material (Polyethylene Terephthalate Glycol-modified (PETG)) to find the optimal stimulation input parameters for bone TE based on two reported in vitro studies.

PCL-PEDOT:PSS electroconductive scaffolds were combined with electrical stimulation to enhance the osteogenic differentiation and mineralization of mesenchymal stem/stromal cells towards improved bone tissue engineering strategies.

Osteochondral (OC) defects affect both articular cartilage and the underlying subchondral bone. Due to limitations in the cartilage tissue’s self-healing capabilities, OC defects exhibit a degenerative progression to which current therapies have not yet found a suitable long-term solution. Tissue engineering (TE) strategies aim to fabricate tissue substitutes that recreate natural tissue features to offer better alternatives to the existing inefficient treatments. Scaffold design is a key element in providing appropriate structures for tissue growth and maturation. This study presents a novel method for designing scaffolds with a mathematically defined curvature, based on the geometry of a sphere, to obtain TE constructs mimicking native OC tissue shape. The lower the designed radius, the more curved the scaffold obtained. The printability of the scaffolds using fused filament fabrication (FFF) was evaluated. For the case-study scaffold size (20.1 mm × 20.1 mm projected dimensions), a limit sphere radius of 17.064 mm was determined to ensure printability feasibility, as confirmed by scanning electron microscopy (SEM) and micro-computed tomography (μ-CT) analysis. The FFF method proved suitable to reproduce the curved designs, showing good shape fidelity and replicating the expected variation in porosity. Additionally, the mechanical behavior was evaluated experimentally and by numerical modelling. Experimentally, curved scaffolds showed strength comparable to conventional orthogonal scaffolds, and finite element analysis was used to identify the scaffold regions more susceptible to higher loads.

Scaffolds are one major component in osteochondral tissue engineering (OCTE) applications, acting as a structural support for cell proliferation and differentiation

Cell culture bioreactors play a paramount role in obtaining successful cell cultures that mature into tissue-like structures

Synthetic polymers, generically named plastics, are manufactured from non-renewable sources, such as fossil fuels [¹]. In 2020, 367 million metric tons of plastic were produced worldwide, and, only in 2018, global plastic waste volume reached 342.6 million metric tons [²,³]. One of the most used plastics is polyvinyl chloride (PVC), which is not environmentally friendly. The goal of this study was to achieve an eco-friendly substitute for PVC tapes while mimicking their properties and applications. In this way, bacterial cellulose (BC) and chitosan (CH) tapes in different concentrations, 1% and 2%, were developed. Mechanical properties, thickness, bonds between BC and CH and degradation tests were assessed in water and under different temperatures. Mechanical testing showed that the combination of the two polymers resulted in better mechanical performances when compared to BC tape (8.52 ± 1.11 MPa); this may be related to the stronger chemical bonds created between the BC and CH. In addition, BC–CH at 1% revealed closer values of strength compared to PVC tapes (703.19 ± 16.18 MPa and 516.92 ± 22.0 MPa, respectively). Moreover, with the present study we were able to conclude that the incorporation of CH increases tape porosity. Interestingly, higher porosities (BC and CH at 2%) resulted in better mechanical properties upon tensile testing (1344 ± 52.87 MPa). Upon contact with water, the BC–CH mixture at 1% proved to be more resistant and not mechanically affected over time, like PCV tape. Thermally, both tapes with CH revealed to be more resistant than the PVC tape. However, the BC–CH tape at 1% was the most stable over time at all temperatures tested. This preliminary study opens new possibilities to the use of these tapes in sport areas, packaging and pharmaceutical or biomedical fields.