For a long time, scientists have been creating tissue cultures in the lab for medical studies. Bioprinting is a whole new world. Geniuses in biotechnology have created a sophisticated, custom 3D printer for printing living tissues and organs.
A bioprinter uses a solution of living cells as is its ink. The injection nozzles follow an MRI or CT scan blueprint for creating tissues and organs to be used in transplant surgeries.
What is 3D Bioprinting?
3D Bioprinting is the additive manufacturing technique of making tissue-like structures from biomaterials. With rigorous improvements, bioprinting could be a panacea for organ shortage in transplant surgeries.
How Does 3D Bioprinting Work?
3D bioprinting works just like the conventional 3D printing, except for the materials used. A digital blueprint file is transformed into a physical 3D object through a layer-by-layer creation process.
The process involves the preparation of digital bio-file, printing, stabilization, and application. Each of these stages influences the other and can impact the overall performance of the final fabricated construct.
Stages in Bioprinting
Pre-bioprinting is the phase where scientists create the digital design of the organ or tissue that the bioprinter will produce. The design sage relies on the computed tomography (CT) and also magnetic resonance imaging (MRI) scans.
The next stage of designing models from CT and MRI scans is the actual printing process. The deposition is layer by layer just as in the conventional 3D printing to form a physical 3D version of the blueprint.
The last stage is post-bioprinting which refers to the chemical and physical stimulation of the 3D printed parts to stabilize the structures for natural use.
Practical laboratory methods for 3D bioprinting
3D imaging in cell printing involves a computational design of biostructures using a CT or MRI scan. 3D imaging is used to create computer models of the tissue or organ anatomy, and the plans usually need little or no adjustment by the doctor or bioengineer.
Another way of creating blueprints for cell printing is by using AutoCAD software. Scientists might have to make fine adjustments to smooth out of defects.
Bioink is a mixture of living cells and synthetic or natural cell-compatible bases such as gelatin, collagen, gelatin, hyaluronan, or alginate. The making of the bioink material has to achieve cell survival, printability and shape fidelity.
3D bioprinting involves depositing the bioink layer-by-layer to create the three-dimensional structure. The layers are as thin as 0.5 mm or less for accuracy. The bioink used in the process has to be highly viscous for solidification into tissue structures.
The freshly layered structure of viscous liquid solidifies to assume the designed shape. That happens even as more layers get deposited. The process of crystallization can sometimes be speeded up with different chemicals, UV light or heat.
Benefits of Bioprinting
1. Bioprinting Could Eliminate the Need for Organ Donors
One usually has to wait for more than two years to get an organ transplant because of fewer organ donors. With three dimensional bioprinting, patients could receive the organs in a matter of hours. It is only a matter of years until we get to that point in medicine.
Using cell printing technology, scientists are experimenting and perfecting living organs like kidneys, livers, lungs, and any other vital organs. Already cell printing has replaced skin grafting in reconstructing burn injuries.
2. Bioprinting can Help to Improve Cell Compatibility
One of the main hurdles during transplant surgeries is cell rejection. That makes the process of finding a compatible donor very tricky. With an incompatible organ tissue transplant, the body of the recipient can activate an immune attack on the new cells, risking the life of the patient.
With 3D cell printing, the cultured cells in the bioink are from the patient, and so there are fewer chances that the body of the patient will reject the new organ.
3. Bioprinting can Replace Volunteers in Drug Tests
3D bioprinting produces tissues that researchers can use in drug tests. Scientists are able to study the effects of drugs in 3D printed human tissues. It’s practical and safe Volunteer patients are saved from risks associated with new drugs.
Limitations of 3D Bioprinting
More research is needed in bioink technology to optimize the synthesis and processing of bioprinting materials.
The current formulation processes have no way of minimizing cell loss and maximizing cell survival during the printing process. Further advancement is also needed to enable vascularization of large tissue constructs and to improve the chemical and mechanical properties of the printed cells.
Currently, 3D printed tissues used in regeneration surgeries do not adequately mimic the native tissues. That is because the 3D printed structure lacks details such as blood vessels. Then again, the use of solvents during tissue fabrication can negatively impact cell growth.
The fact that bioprinted tissues and organs do not have intricate blood vessels such as capillaries, there is, in turn, no oxygen and nutrients supplied to the tissues and neither can they extract waste. That means that the printed cells have no chance of long term survival.
Applications of 3D Bioprinting
Testing drugs on animals might not give the same results as in humans. For that reason, many new drugs fail to get approved for the market.
A drug that works perfectly in animals might have adverse effects on human beings. With the 3D printed human tissues, medical researchers get accurate results in pharmaceutical testing.
3D Printed Bone and Cartilage
The musculoskeletal structure is another area that could benefit a great deal from cell printing research. Some tests have already been done in animals. Australian scientists successfully implanted 3D printed knee cartilage onto sheep.
Even though we are still far from printing a working organ for human transplants, strides have been made in treating conditions such as arthritis with 3D printed cartilage.
Using the person’s stem cells, researchers hope to create 3D printed bones and cartilage and implant them in patients where they can integrate with the body and grow normally.
3D Printed Patches
There have been successful cases of 3D printed patches used in reconstructive surgeries. These 3D printed cell patches can vascularize and form their blood vessels to heal the damaged organs.
3D printed models help researchers to study complex ailments and conditions better. Using 3D printed organs in researchers; scientists can come up with better treatment models and carry out surgeries with accuracy.
The fabrication of biomimetic multi-cellular tissues complete with all cell microenvironment and detailed structures can revolutionize the health sector. Even though we are still far off from fully functional 3D printed organs. There has been commendable progress made in this field of medicine