Utilizing Fish Skin of Ikan Belida (Notopterus lopis) as a Source of Collagen: Production and Rheology Properties

Biofabrication and evaluation of 3D printed and cast PCL / collagen-alginate hydrogel tubular scaffolds for urethral tissue engineering

The urethra is a fibromuscular tube that transports urine from the bladder to the exterior of the body. Congenital disorders and urethral wall strictures caused by traumatic injuries, infections, iatrogenic injuries, and tumor removals can impair urethral function. This research aimed to create a 3D printed scaffold of the urethra using casting and 3D printing techniques, and then the constructed scaffolds were characterized. The final scaffolds consisted of a 3D-printed mesh made of poly-ε-caprolactone (PCL) that was cast with a hybrid hydrogel of collagen-alginate and crosslinked. The swelling of hydrogels containing more alginate in the structure eventually led to the collapse of the hydrogel skeleton. The gradual increase in the compressive strength of the hydrogel scaffolds was consistent with the rise in alginate hydrogels. Rheological properties clearly showed shear-thinning behavior for samples containing more alginate. The viability of rat bladder smooth muscle cells in the CA82 hydrogel (collagen:alginate 8:2 v/v) was higher than in the CA37 hydrogel (collagen:alginate 3:7 v/v). In addition, the expression of functional genes of rat smooth muscle cells was improved in the CA82 hydrogel. The described method and fabricated scaffold could provide a promising approach for urethral reconstruction by tissue engineering.

Hydrogels in Gene Delivery Techniques for Regenerative Medicine and Tissue Engineering

Hydrogels are 3D networks swollen with water. They are biocompatible, strong, and moldable and are emerging as a promising biomedical material for regenerative medicine and tissue engineering to deliver therapeutic genes. The excellent natural extracellular matrix simulation properties of hydrogels enable them to be co-cultured with cells or enhance the expression of viral or non-viral vectors. Its biocompatibility, high strength, and degradation performance also make the action process of carriers in tissues more ideal, making it an ideal biomedical material. It has been shown that hydrogel-based gene delivery technologies have the potential to play therapy-relevant roles in organs such as bone, cartilage, nerve, skin, reproductive organs, and liver in animal experiments and preclinical trials. This paper reviews recent articles on hydrogels in gene delivery and explains the manufacture, applications, developmental timeline, limitations, and future directions of hydrogel-based gene delivery techniques.