What is Fused Deposition Modeling and what are applications of 3D manufacturing in the life sciences

3D-Printing for transplants and cell culture

3D printers © Green Elephant Biotech

Fused Deposition Modeling (FDM), a subset of 3D printing, has revolutionized various industries by enabling the creation of complex geometries and customized products. In the life science sector, FDM's versatility is harnessed to develop innovative solutions, particularly through the use of Polylactic Acid (PLA), a sustainable thermoplastic derived from renewable resources.

How additive (3D) manufacturing works

FDM is an additive manufacturing technique that builds objects layer by layer from thermoplastic materials. The process begins with a digital 3D model, usually created using computer-aided design (CAD) software. This model is then sliced into thin horizontal layers by specialized software, generating instructions for the 3D printer.

The FDM printer heats the thermoplastic filament, such as PLA, to its melting point and extrudes it through a nozzle onto a build platform. The nozzle moves along the X- and Y-axis, depositing material according to the sliced model's specifications. Once a layer is completed, the build platform lowers along the Z-axis, allowing the next layer to be applied. This layering process continues until the entire object is formed. Cooling and solidification occur rapidly, ensuring the layers bond securely.

FDM's precision and control over material deposition enable the creation of complex and highly detailed structures. Print settings, such as layer height, nozzle temperature, and print speed, can be adjusted to optimize the mechanical properties and resolution of the final product.

3D printing applications: Use for biomedical implants and scaffolds

FDM technology enables the production of intricate geometries unattainable through traditional manufacturing methods. This capability is particularly advantageous in creating porous structures that facilitate tissue integration and vascularization in biomedical implants. For instance, FDM can fabricate scaffolds with fully controllable porosity ranging from 20% to 80%, essential for applications like bone tissue engineering (1). Such precision allows for the design of implants that closely mimic the mechanical and structural properties of natural bone, enhancing the success rates of implant integration.

PLA's biocompatibility and biodegradability make it an ideal material for biomedical implants. Its ability to degrade into lactic acid, a naturally occurring metabolite, ensures minimal toxicity and reduces the need for surgical removal after fulfilling its purpose. In tissue engineering, PLA has been combined with hydroxyapatite (HA) to enhance mechanical properties and promote osteogenesis (2). This composite material supports bone regeneration by triggering osteoblast activity, essential for repairing bone defects. FDM-based 3D printing facilitates the creation of patient-specific implants with tailored mechanical properties, improving clinical outcomes (2).

In vitro cell culture studies benefit from PLA-based scaffolds due to their customizable properties. FDM allows the fabrication of scaffolds with controlled porosity and architecture, crucial for mimicking the extracellular matrix (1). These scaffolds provide a conducive environment for cell attachment, proliferation, and differentiation, advancing tissue engineering research. The tunable degradation rates of PLA ensure that scaffolds maintain structural integrity during tissue formation and degrade as new tissue develops, aligning with the desired tissue regeneration timelines. Proven to facilitate cell growth, PLA can be used in adherent cell culture for cell and gene therapy, too. One example is the CellScrew® cell culture system, which utilizes 3D-printed PLA structures to maximize surface area for cell growth and enhance culture efficiency.

The integration of FDM 3D printing in the pharmaceutical and biomedical fields has opened new avenues for personalized medicine and advanced research. The use of PLA in implants and cell culture applications underscores the material's versatility and compatibility with biological systems. Moreover, the ability to fabricate unique geometries with FDM technology enhances the functionality and integration of biomedical devices as well as new fields of application in the life sciences. As research continues to advance, the future of 3D manufacturing holds promising potential for transforming healthcare and beyond.

References

(1) Wang Z, Sun Y, Li C. Advances in 3D printing technology for preparing bone tissue engineering scaffolds from biodegradable materials. Front Bioeng Biotechnol. 2024;12:1483547. Available from: https://www.frontiersin.org/journals/bioengineering-and-biotechnology/articles/10.3389/fbioe.2024.1483547/full#B51

(2) Omigbodun FT, Oladapo BI, Osa-uwagboe N. Exploring the frontier of Polylactic Acid/Hydroxyapatite composites in bone regeneration and their revolutionary biomedical applications – A review. J Long Term Eff Med Implants. 2024;34(3):157-182. doi: 10.1177/07316844241278045 Available from: https://journals.sagepub.com/doi/10.1177/07316844241278045