![]() ![]() Recently, emulsion templating has gained particular attention as a scaffold fabrication technique due to its ability to introduce up to 99% porosity with high interconnectivity into TE scaffolds. To date, several techniques, including electrospinning, (17,18) particle leaching, (19,20) freeze-drying, (21,22) and additive manufacturing, (23,24) have been widely used for fabrication of bone TE scaffolds. Due to these regulatory restrictions, allografts including demineralized and deproteinized bone (DMB and DPB) matrices will likely have more restrictive approval processes and a more challenging pathway for clinical approval. ![]() With the new MDR, human origin cells and tissues or derivatives will also be considered as a high-risk medical device (class III) in addition to those of animal origin (rule 18). (2,7) The regulations of the European Union for medical devices, known as the Medical Device Directive (MDD), (9) were replaced with a new set of Medical Device Regulations (MDR) (10) in 2017, and the new MDR will come into force on May 2020. ![]() (7,8) These treatments considerably affect the physical and biological properties of the bone, and the process results in grafts with comparably poor regenerative potential and/or weak mechanical properties depending on the treatment (demineralization, deproteination, and irradiation). (6) However, allografts need to be processed and cleaned after isolation to prevent an immune response and disease transmission. (5) An acellular alternative to the autograft is an allograft, which is more abundantly available without size limitations. (2−4) However, the autologous bone is mostly harvested from the iliac crest (hip) with limited availability and carries the risk of donor site morbidity. (1) Autogenous bone grafts are considered to be the gold standard as they have osteogenic, osteoinductive, and osteoconductive properties. This study demonstrated that multiscale porous biohybrid scaffolds present a promising approach to improve bioactivity, encourage precursors to differentiate into mature bones, and to induce angiogenesis.īone grafting is the second most frequent tissue transplantation technique worldwide after blood transfusion. The CAM assay indicated that the presence of the in vitro generated ECM on polymeric scaffolds resulted in higher angiogenic potential and a high degree of tissue infiltration. The chick chorioallantoic membrane (CAM) assay was used to explore the angiogenic potential of the biohybrid scaffolds. Cells not only showed improved attachment on biohybrid scaffolds but also exhibited a significantly higher rate of cell growth and osteogenic activity. Mesenchymal progenitors were seeded on PCL-only and biohybrid scaffolds. The biological performance of these constructs was tested in vitro and in vivo. Multiscale porous scaffolds were fabricated, bone cells were cultured on them, and then they were decellularized. Structurally, multiscale porosity is advantageous over single-scale porosity therefore, in this study, we have considered two key points in the design of a bone repair material (i) manufacture of multiscale porous scaffolds made of photocurable polycaprolactone (PCL) by a combination of emulsion templating and three-dimensional (3D) printing and (ii) decoration of these scaffolds with the in vitro generated bone-like extracellular matrix (ECM) to create biohybrid scaffolds that have improved biological performance compared to PCL-only scaffolds. However, such scaffolds need modifications to improve their limited interaction with biological tissues. Synthetic polymers are attractive biomaterials to be used in the manufacturing of TE scaffolds, due to various advantages, such as being relatively inexpensive, enabling precise reproducibility, possessing tunable mechanical/chemical properties, and ease of processing. Both biochemical properties and the architectural features of TE scaffolds are crucial in their design process. Tissue engineering (TE)-based bone grafts are favorable alternatives to autografts and allografts.
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