The ex vivo cultured limbal stem cells over a biocompatible scaffold are used in the management of limbal stem cell deficiency as an ideal replacement for human amniotic membrane (HAM). A novel source of collagen from fish scales (FSC) was used to fabricate the scaffold. In this study, we have evaluated the physicochemical, mechanical, and culture characteristics of FSC and compared with denuded HAM. The cultured corneal cells were characterized by real-time polymerase chain reaction for putative stem cell markers. The swelling ratio, collagenase assay, and microbial resistance of FSC gave better results when compared to those of HAM. The mechanical and physical strengths of FSC were good enough to handle when compared to HAM. Under microscopic observation, epithelial migration was noted at the end of 48 h from limbal explants plated on FSC and on HAM at the end of 72 h. By the end of the 15th day, 90 to 100% confluent growth was seen resembling the morphological features of limbal epithelium. In conclusion, FSCs from a novel renewable biological source were optically clear with sufficient strength, and gave encouraging results in culture studies; the same may be tried as potential candidate for corneal transplantation after in vivo studies.

Recent developments in three-dimensional (3D) printing technology offer immense potential in fabricating scaffolds and implants for various biomedical applications, especially for bone repair and regeneration. As the availability of autologous bone sources and commercial products is limited and surgical methods do not help in complete regeneration, it is necessary to develop alternative approaches for repairing large segmental bone defects. The 3D printing technology can effectively integrate different types of living cells within a 3D construct made up of conventional micro- or nanoscale biomaterials to create an artificial bone graft capable of regenerating the damaged tissues. This article reviews the developments and applications of 3D printing in bone tissue engineering and highlights the numerous conventional biomaterials and nanomaterials that have been used in the production of 3D-printed scaffolds. A comprehensive overview of the 3D printing methods such as stereolithography (SLA), selective laser sintering (SLS), fused deposition modeling (FDM), and ink-jet 3D printing, and their technical and clinical applications in bone repair and regeneration has been provided. The review is expected to be useful for readers to gain an insight into the state-of-the-art of 3D printing of bone substitutes and their translational perspectives.

Due to the presence of electric fields and piezoelectricity in various living tissues, piezoelectric materials have been incorporated into biomedical applications especially for tissue regeneration. The piezoelectric scaffolds can perfectly mimic the environment of natural tissues. The ability of scaffolds which have been made from piezoelectric materials in promoting cell proliferation and regeneration of damaged tissues has encouraged researchers in biomedical areas to work on various piezoelectric materials for fabricating tissue engineering scaffolds. In this review article, the way that cells of different tissues like cardio, bone, cartilage, bladder, nerve, skin, tendon, and ligament respond to electric fields and the mechanism of tissue regeneration with the help of piezoelectric effect will be discussed. Furthermore, all of the piezoelectric materials are not suitable for biomedical applications even if they have high piezoelectricity since other properties such as biocompatibility are vital. Seen in this light, the proper piezoelectric materials which are approved for biomedical applications are mentioned. Totally, the present review introduces the recent materials and technologies that have been used for tissue engineering besides the role of electric fields in living tissues.

Three dimensional printable formulation of self‐standing and vascular‐supportive structures using multi‐materials suitable for organ engineering is of great importance and highly challengeable, but, it could advance the 3D printing scenario from printable shape to functional unit of human body. In this study, the authors report a 3D printable formulation of such self‐standing and vascular‐supportive structures using an in‐house formulated multi‐material combination of albumen/alginate/gelatin‐based hydrogel. The rheological properties and relaxation behavior of hydrogels were analyzed before the printing process. The suitability of the hydrogel in 3D printing of various customizable and self‐standing structures, including a human ear model, was examined by extrusion‐based 3D printing. The structural, mechanical, and physicochemical properties of the printed scaffolds were studied systematically. Results supported the 3D printability of the formulated hydrogel with self‐standing structures, which are customizable to a specific need. In vitro cell experiment showed that the formulated hydrogel has excellent biocompatibility and vascular supportive behavior with the extent of endothelial sprout formation when tested with human umbilical vein endothelial cells. In conclusion, the present study demonstrated the suitability of the extrusion‐based 3D printing technique for manufacturing complex shapes and structures using multi‐materials with high fidelity, which have great potential in organ engineering.