Mucus-based bioink: engineering lung tissue

This bioink could revolutionise the study and treatment of chronic lung diseases, providing a more accurate and reliable model for testing new therapies and potentially offering a new avenue for lung tissue implants.

Understanding lung disease

According to the World Health Organization (WHO) and NHS England lung disease – such as chronic obstructive pulmonary disease (COPD), cancer, and pneumonia – is the third cause of deaths globally, killing millions of people every year. These diseases are notorious for their limited treatment options and high morbidity rates. And despite significant medical advances, there is currently no cure for many chronic lung conditions, with existing treatments focus primarily on managing symptoms rather than offering a definitive solution.

According to the paper, ‘Lung donation and transplant recipient outcomes at independent vs hospital-based donor care units’, the availability of lung donor organs is critically limited. The limitation is further exacerbated by the challenges in managing and maintaining the quality of donor lungs, which affects the survival rates of transplanted lungs. This shortage means that many patients with severe lung diseases remain on waiting lists, often with limited options for treatment

In addition to the scarcity of organs, current research heavily relies on animal models, particularly rodents, to study these diseases and test experimental medications. Although these models have provided valuable insights, they often fall short in replicating the complexities of human pulmonary diseases, leading to challenges in accurately predicting the safety and efficacy of new drugs.

The discovery: a new hope in bioengineering

Acknowledging the limitations of existing models and the need for improved treatment options, the research team has released the paper ‘3D Bioprinting with Visible Light Cross-Linkable Mucin-Hyaluronic Acid Composite Bioink for Lung Tissue Engineering’, which details the development of a novel mucus-based bioink designed for 3D printing lung tissue.

This development has the potential to provide a more accurate and reliable platform for studying lung diseases and testing new treatments.

The technology

The researchers' approach began with mucin, a key component of mucus that had previously been underexplored in the realm of bioprinting. Mucin, an antibacterial polymer, possesses molecular segments resembling epidermal growth factor – a protein known for promoting cell attachment and growth. By chemically modifying mucin with methacrylic anhydride, the team created methacrylated mucin (MuMA), which served as the foundation of the bioink.

To enhance the bioink’s properties, the team mixed MuMA with lung cells and hyaluronic acid – a natural polymer found in connective tissues. Hyaluronic acid was chosen for its ability to increase the bioink’s viscosity, thereby improving cell growth and adhesion. The resulting mixture was then printed in various test patterns, such as round and square grids, before being exposed to blue light to induce crosslinking.

The crosslinking process stabilised the printed structures, forming a porous gel that could readily absorb water – a critical factor in supporting cell survival. The gel’s interconnected pores facilitated the diffusion of nutrients and oxygen, creating an environment conducive to cell growth and lung tissue formation.

Addressing the challenges of lung tissue engineering

One of the biggest challenges in lung tissue engineering has been the development of a bioink that not only supports cell growth but also mimics the complex architecture of lung tissue. The mucus-based bioink developed by the research team addresses this challenge by providing a stable, biodegradable scaffold that promotes the survival and proliferation of lung cells.

While the bioink is nontoxic and gradually degrades under physiological conditions, its potential use in implants, where the printed scaffold could eventually be replaced by newly grown lung tissue, remains an area for further research and validation. Additionally, the bioink's ability to form complex 3D models of lung tissue offers a valuable tool for studying the processes underlying lung diseases and evaluating potential treatments.

A promising future for lung disease treatment

By providing a more accurate and reliable platform for studying lung diseases and testing new treatments, bioink has the potential to greatly impact the future of lung disease research and therapy.

Although the technology is still in its early stages, the findings from this study suggest that one day it may be possible to create fully functional lung tissue for use in implants or to develop more effective treatments for chronic lung conditions. However, further research is necessary to explore these possibilities fully.

This research will undoubtedly offer hope for millions of people worldwide suffering from chronic lung diseases, a welcome step forward in the quest for more effective treatments.