Additive manufacturing (AM), also called as 3D printing, has already revolutionized product design engineering, manufacturing, and is all set to revolutionize medical treatment too. 3D printing allows the rapid conversion of information from digital 3D – rendered in CAD – into physical objects. Unlike conventional manufacturing, in which material is removed, 3D printers work by adding material (hence the term additive manufacturing) and is therefore reduces wastage. There are various 3D printing technologies in use today, and all of them built object layer by layer. The basic components of a 3D printer consist of the hardware (which is the 3D printer itself), the software that communicates between the 3D printer and the CAD design files, and the 3D printing material. There are various types of 3D printers available today that use different technologies like Material Extrusion, Powder Bed Fusion, Vat Polymerization, Directed Energy Deposition, Sheet Lamination, etc. Each technology has certain advantages and disadvantages. Progressive sectors like aerospace, automobile and others are already using 3D printing; let us now turn our attention to how it is changing the face of medicine.
What is Biocompatibility?
3D printers have proven to be a blessing for the healthcare and medical sector. Customization and the ability to print even one quantity without too much cost impact have made 3D printing popular with dentists, surgeons and other medical professionals. One area where 3D printing and 3D printers are set to make a positive impact is bioprinting. However, let us first understand what biocompatibility means, as it directly affects bioprinting.
Biological tissues comprise of three main components that include the cells, the surrounding extracellular matrix, and the intracellular fluid. This fluid provides a favourable environment suitable for cell proliferation and maintenance of phenotype (the observable physical properties of an organism such as appearance, development, and behaviour). Before inserting anything manmade in the human body, it is essential to confirm that it will be accepted by the body. Biocompatibility defines the ability of a material to be accepted by the human body, without producing any adverse reaction or immunological response. In other words, biocompatibility ensures that the material is fully compatible with human body. If a material is not biocompatible, it is rejected by the human body, and does not support proper biological functioning of the body. Bio-composites consist of either bio-material (a material used for a biological purpose) compounds with a filler portion scattered in the material of the matrix, or a structure of alternating portions of various materials.
Bio compatible material is used as surgical guides for dental implants, orthopedic procedures or prototyping medical products; there are other uses as well.
3D bioprinting is an additive manufacturing process wherein living organ-like structures are created using biological materials. Bio printing using appropriate biocompatible material is used to emulate the native tissue architecture as closely as possible. These printable biomaterials can be considered a specialized subclass known as bio inks. These bio inks must support cell viability during and after the 3D printing process and they must retain their structural fidelity. As the number of biocompatible material keeps on increasing, it will enable the manufacturing of biological constructs that can not only serve as regenerative implants in the clinics but also as models of organ systems for applications such as drug screening or a mechanism to study cell behaviour in 3D for research and cell expansion. The growing demand for biocompatible material since the 2010s has spurred several types of bio 3D printers that utilize several different bioprinting technologies. Some of the commercially available 3D bio printers include technologies such as laser assisted bio printing, stereo-lithography bio printing, inkjet bioprinting and extrusion based bio printers.
Biocompatible Material
There is a huge potential for biocompatible 3d printing material in the medical field, and one of the most challenging aspects of bio printing is finding the perfect biocompatible material.The biocompatible 3D printing materials market is forecasted to grow from to $830 million by 2027 at a CAGR of above 23.5% (source: https://www.marketdataforecast.com/market-reports/biocompatible-3d-printing-materials). At about Rs. 82 per $1, this translates to about Rs. 687 crores in Indian currency. The growing demand for biocompatible material in India and other nations is the reason why companies are racing to formulate different biocompatible printing material. As an example, Stratasys’ biocompatible photopolymers provide high dimensional stability and optical transparency for medical applications and are a popular chose with oral healthcare professionals in India and elsewhere. Vat polymerization based bioprinting is another emerging technique for various tissue engineering applications thanks to its high fabrication accuracy. It relies on numerous polymer composites in order to achieve biocompatibility. The overarching factor that limits experimentation is the possibility of biological rejection of an implant. It can lead to adverse reaction that can cause mild to severe symptoms which can even be life threatening. Much of the research into new biocompatible materials is focused on improving acceptance of implants by the body, avoiding unnecessary complications. Pioneering 3D printing companies like Stratasys have already introduced 3D printers that work with varied material; they now also offer an increasing number of biocompatible materials as well.
Future of Biocompatible Material
3D bioprinters relies on the basic assumption that the printed cells can rapidly assemble and form tissues through the process of migration, adhesion, fusion and sorting of cells, and then start to synthesize the desired extracellular matrix. This in turn would facilitate desirable geometrical structure, shape and biological properties of the tissue. 3D bioprinting though considers only the initial state, and assumes the tissue shape remains static. To overcome this limitation, the concept of ‘4D printing’ has emerged recently. It allows the 3D printed biocompatible material or cellular constructs to regenerate and evolve over time.
In summary, these are exciting times for medical science. Technologies like augmented reality (AR), virtual reality (VR), 3D printing, biocompatible material and bio printing are changing health care for better. 3D printers of today are more fast, cost effective and versatile than their predecessors. Industry stalwarts like Stratasys and others are extremely active today in researching for newer and better biocompatible material. Once that happens, bio printing can gain traction and prove to be a valuable aid in alleviating patient health.