Bioprinting is a scientific term that refers to the process of creating living tissues using a 3D printer. This novel technique is transforming many aspects of modern medicine and research, leading to safer and more cost-effective treatments for diseased patients who are otherwise not amenable to other forms of treatment. Biomaterials, in 3D Bioprinting, are materials that have been developed to act as scaffolds for tissue regeneration.
The major applications of biomaterials are in tissue engineering, drug delivery, regenerative medicine and chemical biology. These materials are engineered to have certain properties such as shape, stiffness, porosity, biocompatibility and degradation rates.
When contemplating using biomaterials, it’s important to know about different types of materials available for use in bioprinting. Here’s what you need to know about biomaterials — some common types and how they can be used in bioprinting.
There are many types of biomaterials that can be used for different parts of the body, depending on what tissue being recreated is needed for treatment.
Biomaterial can be of various types such as metals, ceramics, polymers, composites, glasses, naturally originated ones and so on. These materials have wide clinical application as adhesives, sutures, devices, and joint replacement.
From a cell biology perspective, biomaterials serve as scaffolds for host cells to adhere and proliferate. Importantly these biomaterials should allow for nutrient diffusion and waste removal. Biomaterials must have certain mechanical properties to be useful. Biomaterial delivery systems are also important tools for administration of therapeutic agents such as proteins, DNA, small molecules, cells and genes.
Biomaterials are natural or synthetic materials which are designed to intervene with a biological system without adversely affecting the homeostasis of the host. These properties of biomaterials are the main reasons why they have been used to assist in healing applications, to improve tissue function and correct abnormalities within the body. They play a crucial role by serving as a framework for the cellular proliferation, attachment and growth, which conclusively leads to the formation of new tissue. This helps to restore the functional aspects in a body post injury or disease.
Natural Biomaterials : These are derived from natural sources such as plants, animals, bacteria and other microorganisms. In the field of biomaterials, natural biomaterials are broadly classified into three main non-exclusive groups – Plant Based, Animal Based and Microbial sources.
Synthetic Biomaterials : These are primarily engineered in the lab and one of the prime examples being polymers derived from petroleum based on a synthetic route. Synthetic biomaterials are also classified as Biodegradable and Biostable depending on their degradation rate once implanted in an organism.
A vital prerequisite for choosing a biomaterial is based on its biocompatibility, which is the property of being biologically compatible thereby not producing any toxic, injurious, carcinogenic, or immunological response in living tissue. At the same time, the biomaterial must degrade at a rate that matches with the tissue regeneration. The degradation products should not impart any adverse effects.
The mechanical strength of the biomaterial is of real importance here.
The mechanical properties of a biomaterial have a significant effect on its printability and thus on the resulting scaffold structure. Sufficient mechanical strength of a biomaterial is essential to maintain the structural integrity of printed scaffolds through the fabrication process. The biomaterials must possess mechanical properties such as tensile strength, toughness, elasticity and hardness that allow them to act as scaffolds for tissue regeneration. The biomaterials used in 3D Bioprinting also provide the mechanical support required for cell growth and tissue regeneration. Similar to scaffold structures used in construction.
Among the different biomaterials, hydrogels are most eminent. They have been used as bioinks extensively. A few examples of these are alginate, collagen, agarose, gelatin and so on. Hydrogels comprise of a three-dimensional (3D) network of hydrophilic polymers that can swell in water and hold a large amount of water while maintaining the overall structure of the scaffold.
Three broad categories of hydrogels have been used in 3D Bioprinting : ECM derived hydrogels like collagen, fibrin, matrigel; Synthetic hydrogels like peptide based and finally, PHEMA or PEG based or non mammalian derived hydrogels like agarose, alginate, chitosan.
Learn More About Biomaterials in Module 4 of our Online Course in 3D Bioprinting
| Learn About the diverse biomaterials used in 3D Bioprinting, their applications based on cell types, considerations for cross linking and scaffold design |
Although biomaterials come in different types, one must be cognisant of the type of cell or tissue these biomaterials are being used for. Understanding the development stages of the tissue to an intricate detail will clearly define the role the biomaterial has to play in the bioprinting process. Understanding the interaction between different biomaterials and their effect on cells is key to successful bioink formulation. What we have done through this blog is just scratched the surface of one aspect of 3D Bioprinting. You can learn more about the various nuances in 3D Bioprinting in our Fundamental course on 3D Bioprinting. This is just the beginning of our blog posts on the basics of 3D Bioprinting. With a plethora of biomaterials being used and new applications being discovered every year for 3D Bioprinting, we have a lot to share with you. Dont miss out on our future blogs, which will delve into these concepts in detail.
Authors
Dr. Lekshmi Krishna
Dr. Lekshmi Krishna is a Senior Scientist at NBIL. She is a strong research professional with Ph.D. from Vellore Institute of Technology & Master of Science (M.Sc.) (Gold Medallist) focused in Biotechnology from Bharathidasan University. She is a skilled Biomaterial and Bioscience researcher with a demonstrated history of working in the eminent labs, hospital & health care industry. At NBIL she is actively working on the Research & Development activities in the 3D bioprinting sector with a keen vision to address the transplantable organ requirement. Her passion for regenerative medicine, often a very lengthy and complex process, aims to serve the society with a short phrase “bench to bedside”.
Anubha Mehra
Anubha handles marketing, IP and regulatory activities within Next Big Innovation Labs. She is an experienced marketeer who focusses on building customer oriented marketing strategies for biotech led enterprises. Working on the IP and regulatory aspects of NBIL, Anubha understands the various nuances involved in building and marketing patentable and innovative products.
