Advancements in Research on Constructing Physiological and Pathological Liver Models and Their Applications Utilizing Bioprinting Technology

Cardiac tissue engineering: an emerging approach to the treatment of heart failure

Heart failure is a major health problem in which the heart is unable to pump enough blood to meet the body's needs. It is a progressive disease that becomes more severe over time and can be caused by a variety of factors, including heart attack, cardiomyopathy and heart valve disease. There are various methods to cure this disease, which has many complications and risks. The advancement of knowledge and technology has proposed new methods for many diseases. One of the promising new treatments for heart failure is tissue engineering. Tissue engineering is a field of research that aims to create living tissues and organs to replace damaged or diseased tissue. The goal of tissue engineering in heart failure is to improve cardiac function and reduce the need for heart transplantation. This can be done using the three important principles of cells, biomaterials and signals to improve function or replace heart tissue. The techniques for using cells and biomaterials such as electrospinning, hydrogel synthesis, decellularization, etc. are diverse. Treating heart failure through tissue engineering is still under development and research, but it is hoped that there will be no transplants or invasive surgeries in the near future. In this study, based on the most important research in recent years, we will examine the power of tissue engineering in the treatment of heart failure.

DeepFreeze 3D-biofabrication for Bioengineering and Storage of Stem Cells in Thick and Large-Scale Human Tissue Analogs

3D bioprinting holds great promise for meeting the increasing need for transplantable tissues and organs. However, slow printing, interlayer mixing, and the extended exposure of cells to non-physiological conditions in thick structures still hinder clinical applications. Here the DeepFreeze-3D (DF-3D) procedure and bioink for creating multilayered human-scale tissue mimetics is presented for the first time. The bioink is tailored to support stem cell viability, throughout the rapid freeform DF-3D biofabrication process. While the printer nozzle is warmed to room temperature, each layer solidifies at contact with the stage (-80 °C), or the subsequent layers, ensuring precise separation. After thawing, the encapsulated stem cells remain viable without interlayer mixing or delamination. The composed cell-laden constructs can be cryogenically stored and thawed when needed. Moreover, it is shown that under inductive conditions the stem cells differentiate into bone-like cells and grow for months after thawing, to form large tissue-mimetics in the scale of centimeters. This is important, as this approach allows the generation and storage of tissue mimetics in the size and thickness of human tissues. Therefore, DF-3D biofabrication opens new avenues for generating off-the-shelf human tissue analogs. It further holds the potential for regenerative treatments and for studying tissue pathologies caused by disease, tumor, or trauma.