3D Printing in Biotechnology: Current Technologies and Applications

By Nandita Dasgupta, Vineeta Singh, Shivendu Ranjan and 2 more

3D Printing in Biotechnology: Current Technologies and Applications explains the basic designs and recent progress in the application of 3D printing within various biotechnology fields. The book is a compilation of the basic fundamentals, designs, current applications, and future considerations related to this emerging technology, and summarizes the promising application of 3D bioprinting. Chapters contain detailed state-of-the-art knowledge to assist in the development and design of 3D printers, with applications in the medical, food, and environmental fields. This book will appeal to researchers and students from different disciplines, including materials science and technology, food, agriculture, and various biomedical fields.

The content includes industrial applications and fills the gap between the research conducted in the laboratory and practical applications in related industries.

• Offers an introduction to the emerging technologies and sectors in the field of 3D printing
• Discusses the development of sustainable materials and bio-inks
• Provides a guide for medical professionals and practitioners to incorporate current 3D printing technology into their medical practice
• Bridges the knowledge gap for current designs used in 3D printing technology for designing an efficient and innovative 3D printer
• Previews the technological basis for new farming practices and food engineering concepts utilizing 3D techniques

• Language: English
• Publisher: Elsevier Science
• Release date: Sep 23, 2023
• ISBN: 9780128203026

Nandita Dasgupta

Dr. Nandita Dasgupta has vast working experience in Micro/Nanoscience and is currently working at LV Prasad Eye Institute, Bhubaneswar, India. She has exposure of working at university, research institutes and industries including VIT University, Vellore, Tamil Nadu, India; CSIR-Central Food Technological Research Institute, Mysore, India; and Uttar Pradesh Drugs and Pharmaceutical Co. Ltd., Lucknow, India and Indian Institute of Food Processing Technology (IIFPT), Thanjavur, Ministry of Food Processing Industries, Government of India. At IIFPT, Thanjavur, she was involved in a project funded by a leading pharmaceutical company, Dr. Reddy’s Laboratories and have successfully engineered micro-vehicles for model drug molecules. Her areas of interest include Micro/Nanomaterial fabrication and its applications in various fields – medicine, food, environment, agriculture biomedical. She is the author os many books and edited more than 6 books. She has authored many chapters and also published many scientific articles in international peer-reviewed journals. She has received the Certificate for “Outstanding Contribution” in Reviewing from Elsevier, Netherlands. She has also been nominated for advisory panel for Elsevier Inc., Netherlands. She is the associate editor of Environmental Chemistry Letters – a Springer journal of 3.59 impact factor – and also serving as editorial board member and referee for reputed international peer-reviewed journals. She has received several awards and recognitions from different national and international organizations.

Book preview

Preface

Nandita Dasgupta, Vineeta Singh, Shivendu Ranjan, Taijshee Mishra and Bhartendu Nath Mishra

3D printing or additive manufacturing is currently being explored for various applications and industrial uses. It has the potential to transform the design and manufacturing processes with customizable changes in process and product design. This redesign capability can be used for increasing material or energy efficiency, safety, and sustainability for the entire product lifecycle. 3D printing has opened new possibilities and dimensions in the field of biotechnology. The ability to recapitulate biological systems and processes with high precision and reduced risk of inflammatory reaction can be applied in various research areas, including drug delivery, tissue engineering, and food and waste management. Figure 1 highlights the role of 3D printing in tissue engineering, wherein it is possible to mimic the functions of human liver.

Figure 1 Possibility of 3D-printed scaffolds to mimic the structural and functional aspects of human organs.

The book provides a snapshot of the recent ongoing research on how 3D printing can be used in biotechnology. It first gives an overview of the various currently used techniques or types of 3D printers being used for different end applications specific to biotechnology, such as for biomedical devices, diagnostics, therapeutics, tissue implants, scaffolds, organoids, and others mentioned in Chapter 1. Chapter 2 deals with different types of materials, polymers, or bionks used in 3D printing of scaffolds, while Chapter 3 provides an in-depth discussion of 3D-printed tissue scaffolds, their application, limitations, and future scope. Chapter 4 deals specifically with 3D-printed grafts and metal implants while Chapter 5 deals with personalized drug delivery approaches with 3D printing. Chapters 6 and 7 explore 3D printing applications in food and waste management, respectively. The authors provide information about the recent emerging trends and techniques in 3D printing in Chapter 8. The book also covers the sustainability, ethical, and regulatory issues in Chapters 9 and 10. Throughout the book, the authors have demonstrated various examples and offered their insights into each area.

Overall, the book offers technical overview and insights that will be helpful for researchers and medical professionals who are working in various branches of biotechnology. The authors believe that the book will be helpful in contributing toward the widespread adoption of this new technology in various market-wide applications.

Thanks for reading.

1

Three-dimensional printing in biotechnology: techniques and applications

Abstract

Three-dimensional (3D) printing has great potential in sustainable development of industry and society. This technology is already being adopted in automobiles, aerospace, building construction, healthcare, medical devices, agriculture, energy, and food and waste management industries. Today, several small to large size 3D printers are available in the market for prototyping as well as high volume manufacturing. 3D printing technology also has potential in shortening supply chain, reducing waste generation, customizing product design, and supporting on-demand production. In the past decade, various 3D printing techniques have been used in biological and biomedical applications. The biotechnology field offers promising potential for 3D printing applications in designing and fabricating medical devices, biomedical devices, diagnostics, tissue implants, hydrogels, scaffolds, micro-nanofluidic devices, including organ-on-chip, organoid-on-chip, and lab-on-chip as point-of-care devices. The emergence of 3D printing techniques in biotechnology (popularly called 3D bioprinting) propelled the demand for novel biomaterials, cross-linkers, polymers, and bioinks to explore new applications for addressing the challenges of various industries as well as the society for sustainable development, food security, health security, energy security, medicine, healthcare and well-being, novel food materials, and nutrition. 3D printing applications in biotechnology are expected to transform the way we look at the future developments in bioenergy production, drug and vaccine discovery, therapeutics, including antivirals, antibiotics, gene therapy, cell therapy, and tissue therapy, personalized and precision medicine, personalized food and plant-based metabolites, and biomaterials. Over the past few years, many 3D printing techniques have emerged and are being used by biotechnology researchers. Here, we summarize the currently used 3D bioprinting techniques and their applications in biotechnology field.

Keywords

3D printing; 3D bioprinting; techniques; biotechnology; tissue engineering; additive manufacturing

Chapter outline

Outline

Introduction 1

Evolution of three-dimensional Bioprinting 2

Three-dimensional bioprinting technology 4

Three-dimensional bioprinting techniques 5

Extrusion-based bioprinting 5

Light-assisted bioprinting 8

Droplet-based bioprinting 11

Application of three-dimensional printing in various sectors of biotechnology 14

Tissue and organ fabrication 15

three-dimensional-printed organoids 15

Organoid-on-chip 16

Organ-on-chip 17

Food printing 18

Biomedical implants and anatomical models 19

Drug delivery and drug development 20

Bioprinting in plant science 20

Microbial cell printing 21

Bioprinting of nanomaterials 21

Conclusion 22

References 23

Introduction

Three-dimensional (3D) printing is a digitized and flexible technology that converts geometrical forms into physical objects by successive addition of materials. The first 3D printer based on Stereolithography (SLA) was developed by C. W. Hull in 1984. The 3D printing technology is also popularly known as additive manufacturing (AM) and nowadays widely used due to its distinctive advantages in various applications in aerospace, architecture, fashion, food, and biologics industries (Godoi, Prakash, & Bhandari, 2016; Jiang, Yu, Xu, Ma, & Liu, 2020; Liu, Hamid, Snyder, Wang, & Sun, 2016). The computer-aided design (CAD)/3D modeling or image processing software are used to design 3D structures and thereafter these designed objects are fabricated in a layer-wise manner using a 3D printer.

3D printing in biological and biomedical field is also termed as 3D bioprinting, which allows the development of blood vessels as well as customized tissues for implantation as heart valves, trachea, and myocardial tissues. 3D-printed flowers, artificial photosynthetic systems, wearable electronics, e-plants, and cell-laden scaffolds are some of the applications of this novel technology in plant science research. Furthermore, 3D-printed fabricated ecosystems, EcoFABs, allow the controlled study of plant microbiome interaction (Zengler et al., 2019).

Evolution of three-dimensional Bioprinting

Klebe (1988) demonstrated the first application of bioprinting by depositing cells in 2D structure using a HP inkjet printer. Furthermore, Odde and Renn (1999) demonstrated the first 3D patterning of live cells to form complex tissue analogs using laser-assisted bioprinting. In 2002, Landers, Hübner, Schmelzeisen, and Mülhaupt (2002) developed the first extrusion-based bioprinter that was later commercialized as 3D-Bioplotter. In 2003, Wilson and Boland (2003) bioprinted live cells by modifying the office inkjet printer into inkjet-based bioprinter. Further developments in 3D printing took place to minimize the cost of printing, so as to make it affordable for every end user. In 2006, Jayasinghe, Qureshi, & Eagles (2006) used electric field-driven jetting phenomenon, known as electrohydrodynamic (EHD) jetting, to deposit living cells. In 2009, Norotte, Marga, Niklason, and Forgacs (2009) developed scaffold-free vascular tissue through bioprinting. In 2012, Skardal et al. (2012) made an attempt of bioprinting a mouse model. In 2015, Gao et al. (2015) developed coaxial technology for the fabrication of tubular structure. In 2019, Lee, Abelseth, de la Vega, and Willerth (2019) succeeded in bioprinting collagen to develop human heart model using suspended hydrogel technology. With the abovementioned examples, it is evident that 3D bioprinting techniques have the potential to address challenges of conventional tissue engineering fabrication methods. A brief timeline of historical developments in 3D printing/3D bioprinting as well as their future applications is given in Fig. 1.1.

Figure 1.1 (A) A brief timeline of historical developments in 3D printing/bioprinting. (B) Futuristic application of bioprinting of tissues and organs for the development of personalized organs ( Sekar et al., 2021). Source: Reproduced with permission from Sekar, M.P., Budharaju, H., Zennifer, A., Sethuraman, S., Vermeulen, N., Sundaramurthi, D. &Kalaskar, D.M. (2021) Current standards and ethical landscape of engineered tissues-3D bioprinting perspective. Journal of Tissue Engineering, 12, 20417314211027677. https://doi.org/10.1177/20417314211027677.

3D bioprinting techniques offer selective distribution of cells, biomaterials, growth factors, or combinations thereof, to manufacture living tissues and organs in three dimensions. Fabrication of such cell-laden constructs, thus, helps in steering cellular activity. Biocompatible materials, such as polymers, hydrogels, and composite materials, are used to make scaffolds to mimic the complex architecture and mechanical properties of natural tissues. The development of solvent-free, aqueous-based systems enable direct printing of biological materials into 3D scaffolds that can be used for transplantation with or without seeded cells (Murphy & Atala, 2014). Today, various tissue models derived from 3D bioprinting techniques are being used to examine drug delivery pathways. Moreover, 3D bioprinting allows the development of novel drug delivery systems with unprecedented precision and complexity. Furthermore, it enables achieving detailed spatial composition and controlled release pattern of drug, which was not possible through previous techniques. Now, patient-specific, customizable, and on-demand personalized medicine, implants, and wearable devices are becoming a reality due to the speed and flexibility offered by 3D printing technology.

The selection of biomaterials for bioink formulation depends on the printability of materials, its characteristics, and properties for external applications. Whereas bioink for implantable constructs require characteristics of biomaterials that are specific for both physiological conditions and interactions with the human body. Therefore, overall, printable biomaterials must have characteristics such as printability, biocompatibility, mechanical properties, degradation kinetics, and should exhibit tissue mimicry. These properties are linked to the type of printing methods being used. For example, in bone tissue formation, stiff materials are required for load-bearing capacity. Due to the inherent stiffness of printed biomaterials, the majority of 3D-printed constructs are suitable to be used in bone or cartilage applications mimicking the natural stiffness of these tissues. However, it certainly makes discovery and development of novel biomaterials more challenging.

Three-dimensional bioprinting technology

The 3D printing process starts with the creation of a 3D model using CAD software or 3D scanning system (optical, MRI, CT, or laser). Once the 3D model is developed, it needs to be converted to the STL file format to be recognized by slicer software, which stores the information of the model surfaces as a list of coordinates of triangulated sections. The slicing process converts the stored information or data into a G-code file. This G-code file contains all geometrical information or data of the 2D cross-section of the designed object to be printed. The printer then avails G-code files to deposit the bioink material layer by layer, which is built one upon another until the desired 3D object is finally created. A working diagram of 3D printing process is given in Fig. 1.2. Once printing is finished, the bioprinted object is sent for postprocessing operations to finally obtain a finished bioconstruct.

Figure 1.2 Representation of three-dimensional (3D) printing working diagram from designing of object to obtain 3D-printed model.

In 3D bioprinting, the material being printed is called bioink, which consists of living cells, biomolecules, and biomaterials to actively print the tissues of living cells. The 3D bioprinting of tissue and organs finds many applications in regenerative medicine. For some bioprinting applications, the process workflow typically starts with data acquisition by MRI or CT of the tissue or organ to be fabricated. The medical image data sets, thus, provide essential information about the macrostructure of the tissues and organs. However, in case where the information at microstructure is not possible, the advanced microscopy techniques (fluorescent, confocal, or two-photon) can provide some crucial details at the cellular level. Currently, MRI or CT data sets are mainly used to design the overall volume of the object to be fabricated, while the information about the infill is normally designed through open source or proprietary softwares. Therefore, it is evident that there are still challenges that need to be addressed for a more innovative bioprinting strategies. Thus, the true power of the 3D bioprinting technology is yet to be explored. It might take some more time to establish this technology as gold standard in biotechnology research.

Three-dimensional bioprinting techniques

Over the past decade, several bioprinting techniques have emerged based on different driving and dispensing mechanisms and, presently, these techniques are being used to fabricate various tissues and organs by selectively dispensing cells or hydrogels, or combinations thereof. 3D bioprinting techniques are broadly categorized into three major modalities, namely extrusion-based, light-assisted, and droplet-based, which are further subclassified into various categories according to material type, cell viability, and surface resolution. A broad classification of various 3D bioprinting techniques is given in Fig. 1.3. Each technique has its own unique advantages and constraints. Hence, selection of a suitable bioprinting technique is utmost important to obtain 3D bioprinted construct of choice. A comparison of various bioprinting techniques is given in Table 1.1.

Figure 1.3 Classification of three-dimensional bioprinting techniques.

Table 1.1

Extrusion-based bioprinting

Extrusion-based bioprinting (EBB) techniques use pressure as a driving force for bioprinting. It consists of a print head, a print stage, and a control system for controlling printing speed, temperature, and print location. In this technique, a continuous strand of bioink is extruded through a syringe and needle by gravitational and/or mechanical force, or by pressurized air (Ning et al., 2020). EBB has fast printing speed and can deposit large cell densities, which makes it a viable technique for large-sized scaffolds. Depending on the driving force and dispensing mechanism, EBB can be classified into two types, i.e., mechanical and pneumatic. The former utilizes mechanical force for extrusion through either piston or screw-driven system. Piston is used for the extrusion of cell-laden bioinks, whereas screw-driven system is used for the printing of acellular materials. Valve-based or valve-free pneumatic 3D bioprinters use air pressure to promote the extrusion of bioink through the print head and nozzle. Despite sharing the same working principle, the two platforms (mechanical and pneumatic) utilize different mechanisms for dispensing bioink. A schematic diagram of mechanical extrusion bioprinting and pneumatic extrusion bioprinting is given in Fig. 1.4.

Figure 1.4 Schematic diagram of extrusion-based bioprinting (A), pneumatic extrusion printing (B), and (C) mechanical extrusion bioprinting ( Jeong, Nam, Jang, and Lee, 2020). Source: Reprinted from Jeong, H.-J., Nam, H., Jang, J., Lee, S.-J. (2020). 3D bioprinting strategies for the regeneration of functional tubular tissues and organs. Bioengineering, 7, 32.

The major limitation of EBB is that during bioprinting, the incorporated cells go through pressure and shear forces, which may lead to rupturing of cell membranes and further cause loss in their integrity if the process-induced forces exceed the cell membrane threshold. Moreover, extrusion printing has low resolution and experiences clogging problems (Naghieh, Sarker, Sharma, Barhoumi, & Chen, 2020). In spite of these limitations of EBB, due to its versatility, affordability, and ability to print porous constructs and large constructs, it has now been utilized by researchers worldwide to bioprint cells, tissues, tissue constructs, organ models, and organ-on-a-chip. Thus far, a wide variety of tissue constructs have been successfully fabricated with EBB, such as cartilage, vasculature, bone, skin, liver, and cardiac constructs, employing bioinks containing cells, tissue spheroids, decellularized matrix components, cell-laden hydrogels, and microcarriers.

The working principal of extrusion bioprinting is similar to fused deposition modeling (FDM, a 3D printing approach that uses melted filament materials as ink) and is widely used in the development of drug delivery systems, personalized medicine, and biomedical devices. Polycaprolactone is a widely used biocompatible material for applications in wound dressings, tissue engineering, and drug delivery. Thermoplastic polyurethane is another biocompatible material broadly used for bone regeneration, bone replacement, and drug or gene delivery.

Light-assisted bioprinting

Light-assisted bioprinting (LAB) is an emerging and promising in situ bioprinting technique that offers high printing resolution and precision. This bioprinting system consists of a light source, a transparent substrate, a biocompatible material to be printed and an energy-absorbing layer. LAB can be broadly classified into two types, i.e., photopolymerization-based and cell transfer-based. Photopolymerization-based bioprinting techniques include stereolithography (SLA), digital light processing (DLP), and two photon polymerization (2PP). While cell transfer-based bioprinting technique is laser-induced forward transfer (LIFT). LAB techniques enable precise positioning of cells in 3D structure construct either by photopolymerization or cell transfer techniques.

Photopolymerization-based three-dimensional bioprinting techniques

Photopolymerization-based 3D bioprinting technique uses biocompatible polymer bioink in liquid form in the presence of photoinitiators that get photopolymerized upon exposure to light source of various wavelengths. These bioprinting techniques include SLP, DLP, and 2PP.

Stereolithography

Stereolithography (SLA) is the first and the most commonly used light-based bioprinting technique that fabricates the 3D structure construct with high resolution and accuracy. SLA is a nozzle-free technique based on curing of photopolymer resin using ultraviolet laser beam. Initially, the resin is in a liquid state at room temperature, which is then converted into the 3D object from geometric data obtained from a CAD file. Hull (1984) developed the process of photocuring for the first time, which was later commercialized. Here, the laser beam scans the bioink for purpose of curing. Once the first layer is solidified, the building platform moves to bring a new layer of bioink plastered on top, and the photocuring process is repeated. The layers are added to each other and the entire object is finally developed. Through this technique, 3D objects having complex structure can also be printed. A schematic diagram of SLA-based 3D printing system is given in Fig. 1.5. In SLA bioprinting, bioink containing cells and hydrogel are photocured using a laser with a specific wavelength. The major challenge of SLA-based bioprinting is that the cells are damaged due to ultraviolet laser beam and photocurable bioink (Duan, Hockaday, Kang, & Butcher, 2013). The two other approaches of photopolymerization are vector-wise or direct laser writing and mask irradiation or mask-based writing.

Figure 1.5 Schematic diagram of stereolithography-based three-dimensional printing system.

Digital light processing

Digital light processing (DLP) technique is similar to SLA just with a difference in light source. This technique requires 2D image from digital micromirror device (DMD) to polymerize an entire pattern using a single projected image. This technology uses a projector located at the bottom of the bioink pool. The DMD consists of micro-sized mirrors for fast and precise projection of UV/Visible light that facilitates rapid generation of bioprinted construct. The projector helps cover the entire surface of the layer leading to rapid bioprinting. The DLP technique allows fabrication of the construct in a layer-by-layer fashion resulting into higher resolution printing compared to SLA. In DLP, the projector resolution is directly linked to the print quality of the fabricated construct. This feature of DLP bioprinting technique is suitable for fabricating various 3D microstructures, such as hydrogel scaffolds in drug delivery systems, artificial tissues, and biomedical devices. A working diagram of DLP 3D printing technique based on DMD projector is given in Fig. 1.6. The DMD-projection bioprinting technique is capable of printing bioinks with high degree of precision (Huang, Qu, Liu, & Chen, 2014). Such LAB technique has recently attracted much attention due to its superior printing speed, high resolution, and high cell viability (Zheng et al., 2021). This technique is also suitable for multiple-tissue reconstruction or repair such as spinal cord, peripheral nerve and blood vessel injury (Bracaglia et al., 2017). Here, cell viability increases beyond 85%–95% due to short printing time and nozzle-free printing