3D Printing Technology in Biomedicine

Introduction

Since the invention of the 3D printers in 1986 by Charles Hull, the use of 3D printing technology in medicine field is rapidly expanding. The technology is proving of critical use in improving patient care, by enabling the doctors to produce the exact multidimensional models of the trouble spots in a patient and simulate the exact procedures appropriate in treating the problem(1). This technology has opened new opportunities in the medical field such as in creating objects with complex internal structures. The technology is proving to be of great assistance in various medical applications. These applications include illnesses involving the brain and nerve degeneration. In addition, the technology is applicable in bio printing organs and tissues, hence allowing the doctors to obtain medically relevant baseline data for the patient and develop intervention strategies early (2). The accuracy precision and control of these printers is ideal for such sophisticated uses when compared to normal printers. Researcher are also working on use the 3D printing technology in fabricating artificial and customized dental products, prosthetics and organ transplants. This has a significant advantage when producing customized medical products.

Overview of the 3D printing technologies

The 3D printing Technology allows doctors to get inside a patient’s body in a non-invasive way and acquire critical data on an existing particular disease using the infrared or sound wave imaging technology. The choice of method used to acquire the digital file is important, as it determines the quality of the object. If the file is low resolution, there might be a difference between the created object and the original (1). The digital file obtained is used through additive processes by building up layers at a time from the bottom successively to create a three dimensional solid object This makes it possible to print more complex shapes as compared to the traditional printing (3). The 3D emerging technology has also other significant differences from the traditional printing technologies. It allows fabrication of complex architectures using design technology aided by computers and addictive manufacturing technology. This technology uses inkjet cell suspensions and deposition solutions. The major 3D printing technologies include light mediated stereo lithography, polymeric selective laser sintering, fused deposition modeling, colloidal and non-colloidal suspension and hot melted synthetic thermoplastics and composites among several others. 

The most used 3D printing technology is the inkjet, selected laser printing and extrusions based printing. The selected laser printing (SLS) uses the high fused power laser fused with a powdered substrate. The lasers melts the powder to obtain the shape of the 3D object. The advantage of selected laser printing method is that it does not require support structures, while printing the 3D models unlike the other printing approaches. The Inkjet printing in 3D printing technology is also widely applicable because it’s compatible with majority of the materials and it’s relatively low cost. However, the inkjet method has drawbacks in terms of its application when printing vicious solutions or suspensions and high fraction polymer. In addition, it’s not applicable when using inks with a high concentration of Nano-particles, such as calcium phosphates because they clog the dispensing tool when working under pressure (3). This means they cannot be applied with drug-eluting microspheres inks. Therefore, only extrusion based 3D printing method is applicable with such materials.

3D printing Use in biomedical fields.

Surgery

As aforementioned, the use of 3D technologies in the medical field is rapidly growing. One of its widespread use in the medical field in surgery in head and neck imaging.  In surgery, carrying out facial reconstruction after tumor surgeries is a complicated procedure, requiring a significant amount of time. However, surgeons have find the use of the 3D printing technology important, as its enables the surgeons to create a replica of the patient’s bone anatomy before surgery, therefore reducing operation time(4). This is also beneficial to the patients as it reduces the amount of time spent under anesthesia. Similarly, this concept on 3D technologies is also applied in carrying out orthopedic surgeries (1). Also in surgery, 3D technologies is used in rehearsing for delicate procedures, by creating models which are used by the surgeons to familiarize  with the patients and predict possible problems that might be experienced during the actual surgery. Another application of the 3D technologies in the medical field is in musculoskeletal imaging. The technology is being applied to create custom prosthesis for correcting skeletal disorders such as the multiple exostoses, which is hereditary. Using the technology, it is possible to create the structure models, which can be used in surgical excision without harming the surrounding structures.

The 3D printing technologies have a wide application in planning for various types of surgeries.  Other type of surgeries where the technology use is rapidly growing is the cardiac imaging, to plan sensitive cardiac surgeries such as in correcting congenital heart defects. Using created 3D models, surgeons are able to make critical decisions before carrying out the surgical repair by comparing the models with the actual anatomy hence carry out the surgery with confidence. The same case to gastrointestinal imaging, which is necessary when carrying out sensitive pancreases surgeries. The 3D printing technology has been used to create exact models of the anatomical locations for the pancreatic cancer tumors and the surrounding structures, hence enabling successful prognosis of the pancreatic cancers, which has among the lowest survival rates of 4%(1). Therefore, the technology helps acquire a good visualization of the pancreases and the tumor assisting in making critical and intraoperative decisions resulting in improved patient outcome.

Training physicians

The 3D printing technologies has proven to be of significant used in physicians and medical students trainings especially on complex bone structures surgical treatment and critical patient care. The models created using 3D technologies are realistic and have a big potential to help medical trainees easily learn on complex medical procedures such as neurosurgery in reduced hours and using less supervision. The models are created using the data obtained from actual patients, which is more effective than the simulation used in the current learnings, that lacks realism (5). Similarly, these models are safe to work with and provide a realistic environment for teaching medical students especially on complicated medical procedures.

Customized prosthesis

The 3D printing technology can be used to customize prosthesis according to the specification and the needs of the patients more effectively when compared to the traditional alternatives (5). In addition, such prosthesis are more comfortable to the wearer and low cost, which is advantageous than the traditional prosthesis especially for children who are growing faster. This technology is therefore a revolution in this field, and with the technology developing, research is ongoing to use the technology in creating expandable prosthesis which do not require replacement.

Drawbacks and limiting factors to the use of 3D technologies in biomedical fields.

Despite its promising use in the biomedical field and their projected exponential growth in future, 3D technologies have several drawbacks and limitations. One of the biggest factor is cost. The cost of implementing the use of 3D printers in the clinical practice is significantly high. This is because unlike in the commercial industry use, medical practice requires highly specialized 3D printers, with high resolutions to create exact models of the original anatomy. In addition, the use of 3D printing technology requires the use of accompanying equally expensive hardware to ensure privacy and safety of patients. Another factor which is considerably limiting the use of 3D technologies in acquiring specialized technology for each of medical area, which at times requires urgent interventions and innovations so as to make the technology useful. Time spent in processing of medical data to isolate the required areas of interest for medical use is also significantly high, reducing the usefulness of the technology (2). However, several companies have started processing applicable software to speed up the processing of this data for reconstruction of 3D models as well as creating dedicated radiology stations for converting such information to appropriate data files for use by different 3D printing technologies.

Conclusion

The 3D printing technology is gaining a significant effect on the medical fields, as a powerful tool which can be used to create exact anatomical models of complex structures. These structures have proven to be of significant use in assisting complicated surgeries such, creating customized prosthetics and training medical professionals. As the technology continues to develop, 3d printing technologies promises to uncover numerous opportunities which will benefit various medical professionals, as consequently, it’s therefore one of the emerging biomedical technologies which are important to explore and evaluate.

References

1. Marro A, Bandukwala T, Mak W (2016) Three-Dimensional Printing and Medical Imaging: A Review of the Methods and Applications. Current Problems in Diagnostic Radiology 45:2-9. Available at: http://www.cpdrjournal.com/article/S0363-0188 (15)00112-7/pdf [Accessed October 13, 2017].

• Ventola, C. L. (2014). Medical Applications for 3D Printing: Current and Projected Uses. Pharmacy and Therapeutics, 39(10), 704–711. Available at: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4189697/ [Accessed October 13, 2017].

• Jakus A, Rutz A, Shah R (2016) Advancing the field of 3D biomaterial printing. Biomedical Materials 11:014102. Available at: http://shahlab.northwestern.edu/files/2016/01/advancing-the-field-of-3D-biomaterial-printing-1ovgjlq.pdf [Accessed October 12, 2017].

• Tack P, Victor J, Gemmel P, Annemans L (2016) 3D-printing techniques in a medical setting: a systematic literature review. BioMedical Engineering OnLine 15. Available at: https://biomedical-engineering-online.biomedcentral.com/articles/10.1186/s12938-016-0236-4 [Accessed October 14, 2017].

•  Dodziuk H (2016) Applications of 3D printing in healthcare. Polish Journal of Cardio-Thoracic Surgery 3:283-293. Available at: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5071603/ [Accessed October 14, 2017].