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The combination of macro- and microporosity is a potent manner of enhancing osteogenic potential, but the biological events leading to this increase in osteogenesis are not well understood. In this study, we investigated the effect of a dual pore size scaffold on the physical and biological properties, with the hypothesis that cell condensation is the determining factor for enhanced osteogenic differentiation. To this end, a hierarchical scaffold possessing a dual (large and small) pore size was fabricated by combining two additive manufacturing techniques: melt electrospinning writing (MEW) and fused deposition modeling (FDM). The scaffolds showed a mechanical stiffness of 23.2 ± 1.5 MPa similar to the FDM control scaffold, while the hybrid revealed an increased specific surface area of 1.4 ± 0.1 m 2 /g. The scaffold was cultured with primary human osteoblasts for 28 days, which showed enhanced cell adhesion and proliferation. The hierarchical structure was also beneficial for in vitro alkaline phosphate activity and mineralization and showed an increased expression of osteogenic protein and genes. Mesenchymal condensation markers related to osteoblastic differentiation (CDH2, RhoA, Rac1, and Cdc42) were upregulated in the hybrid construct, demonstrating that the MEW membrane provided an environment more suitable for the recapitulation of cell condensation, which in turn leads to higher osteogenic differentiation. In summary, this study demonstrated that the hierarchical scaffold developed in this paper leads to a significant improvement in the scaffold properties such as increased specific surface area, initial cell adhesion, cell proliferation, and in vitro osteogenesis.

Although bioinks with both high printability and shape fidelity while maintaining high cell viability are developed, the biofunctionality of the resulting bioprinted construct is often overlooked. To address this, a methacrylated gelatin (GelMA)-based bioink biofunctionalized with bone particles (BPs) is developed as a personalized treatment strategy for bone regeneration. The bioink consists of incorporating BPs of various sizes (0-500 µm) in GelMA at various concentrations (ranging from 5 to 15% w/v). The printability of the bioink is systematically investigated and it is demonstrated that a 15% w/v BP-loading results in high print quality for 10% and 12.5% GelMA concentrations. Rheological evaluation reveals a strong shear thinning behavior essential for printing and a high gel strength in bioink with 15% w/v 0-500 µm BPs for both GelMA concentrations. In addition, the printability of the bioink and the metabolic activity of the resulting scaffolds are dependent on both the concentration of hydrogel and size of the BPs. Importantly, the cells initially contained in the BPs are able to migrate and colonize the bioprinted scaffold while maintaining their capacity to express early osteogenic markers. This study demonstrates the feasibility of bioprinted viable BPs and may have some potential for chairside clinical translation., (© 2020 Wiley‐VCH GmbH.)

Air frying technique was used for the preparation of fish cutlet-a popular fish snack with low fat content, better protein content and color. The process conditions viz: temperature varying from 160 to 200 °C and time varying from 5 to 15 min were optimized using response surface methodology. A factorial design with 9 runs satisfying rotatability conditions under correlated errors was formulated for the experiment. The parameters of first order response surface model with interaction were estimated by generalized least square method. The optimum temperature-time combination for air-frying condition was found to be 180 °C and 12 min, respectively for low fat content, better protein content and colour, comparable texture profile and sensory acceptability when compared to deep fried fish cutlet samples. Air-fried fish cutlets can be a healthier protein rich snack product as an alternative to deep fat fried fish cutlets., (© Association of Food Scientists & Technologists (India) 2020.)

Aim: Atherosclerosis is a common cardiovascular disease causing medical problems globally leading to coronary artery bypass surgery. The present study is to fabricate core/shell nanofibers to encapsulate VEGF for the differentiation of mesenchymal stem cells (MSCs) into smooth muscle cells to develop vascular grafts., Materials & Methods: The fabricated core/shell nanofibers contained polycaprolactone/gelatin as the shell, and silk fibroin/VEGF as the core materials., Results: The results observed that the core/shell nanofibers interact to differentiate MSCs into smooth muscle cells by the expression of vascular smooth muscle cell (VSMC) contractile proteins α-actinin, myosin and F-actin., Conclusion: The functionalized polycaprolactone/gelatin/silk fibroin/VEGF (250 ng) core/shell nanofibers were fabricated for the controlled release of VEGF in a persistent manner for the differentiation of MSCs into smooth muscle cells for vascular tissue engineering.

Recent advances in bioprinting technology have been used to precisely dispense cell-laden biomaterials for the construction of complex 3D functional living tissues or artificial organs. Organ printing and biofabrication provides great potential for the freeform fabrication of 3D living organs using cellular spheroids, biocomposite nanofibers, or bioinks as building blocks for regenerative therapy. Vascularization is often identified as a main technological barrier for building 3D organs in tissue engineering. 3D printing of living tissues starts with potential support of biomaterials to maintain structural integrity and degradation of certain time periods after printing of the scaffolds. Biofabrication is the production of complex living and nonliving biological products from raw materials such as cells, molecules, ECM, and biomaterials. Generally, two basic methods are used for the fabrication of scaffolds such as conventional/traditional fabrication processes and advance fabrication processes for engineering organs. A wide range of polymers and biomaterials are used for the fabrication of scaffolds in tissue engineering applications. 3D additive manufacturing is advancing day-by-day; however, there are various critical challenging factors used for fabricating 3D scaffolds. This review is aimed at understanding the various scaffold fabrication techniques, types of polymers and biomaterials used for the fabrication processes, various fields of applications, and different challenges faced in their fabrication of scaffolds in regenerative therapy.