[Week 6] NPTEL Organ Printing Assignment Answers 2023

NPTEL Organ Printing Assignment Solutions 2023

NPTEL Organ Printing Week 6 Assignment Answers 2023

1. In the context of bioprinting a functional heart tissue, which parameter is more critical, cellular alignment, vascularization or proper synchronization of electrical impulses and contractility? Justify your choice.

• Cellular alignment; it enables uniform electrical propagation and coordinated contractions
• Vascularization; it provides nutrient supply but doesn’t significantly affect electrical coupling
• Both are critical and electrical synchronization and contractility is dependent on them
• Electrical synchronization and contractility is considered of utmost importance

Answer :- d

2. Consider the integration of cardiomyocytes and endothelial cells in a bioprinted cardiac construct. Which cellular ratio is more conducive to functional heart tissue?

• High cardiomyocyte-to-endothelial cell ratio; it enhances contractile strength and tissue robustness
• Balanced ratio; it promotes vascularization and oxygen diffusion, crucial for tissue survival
• Both ratios are equally functional; tissue performance is independent of individual cell composition
• Cellular ratio is irrelevant in bioprinting heart tissue; construct functionality is predetermined

Answer :- b

3. In the bioprinting of kidney tissue, which is more challenging to replicate: the structural complexity of nephrons or the intricate filtration processes within glomeruli?

• Structural complexity of nephrons; glomerular filtration processes are relatively standardized
• Intricate filtration processes within glomeruli; nephron structures are relatively uniform
• Both challenges are equally formidable; one cannot be more challeging over the other
• Neither aspect poses significant challenges; kidney bioprinting is inherently simplified

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Answer :- a

4. When designing a bioink for bioprinting liver tissue, which property is more crucial that supports hepatocyte metabolic functions?

• Mechanical stiffness resembling native liver; it maintains tissue integrity and vascular stability
• Dynamic microenvironment; it ensures hepatocytes’ metabolic responsiveness and function
• Both properties are equally important; one cannot be prioritized without compromising the other
• Neither property significantly influences liver tissue function; cell behaviour dominates outcomes

Answer :- b

5. In the bioprinting of lung tissue, the integration of mechanical stretch simulation during tissue maturation can enhance tissue elasticity and mimic physiological breathing motions. How does the inclusion of mechanical stretch affect cell alignment, ECM remodelling, and tissue contractility within the bioprinted lung construct?

• Mechanical stretch enhances cell alignment and ECM remodelling but might hinder tissue contractility
• Mechanical stretch optimizes tissue contractility and ECM remodelling but may not significantly impact cell alignment in the bioprinted construct
• Balancing mechanical stretch simulation optimizes cell alignment, ECM remodelling, and tissue contractility
• Mechanical stretch simulation has minimal impact on cell alignment, ECM remodelling, and tissue contractility within the bioprinted lung construct

Answer :- c

6. Discuss the potential role of ALI culture in promoting the development of functional respiratory epithelium within the bioprinted lung tissue.

• The establishment of an air-exposed environment enhances secretory cell differentiation and mucociliary clearance mechanisms in bioprinted constructs
• ALI culture disrupts secretory cell differentiation and mucociliary clearance mechanisms, leading to compromised lung tissue functionality
• ALI culture introduces imbalanced cellular composition and variability between ciliated and non-ciliated cells
• The impact of ALI culture on secretory cell differentiation, but not mucociliary clearance mechanisms, has critical influence on lung tissue functionality

Answer :- a

7. Arrange the following organs based on the challenges of bioprinting –

• Heart > Liver > Lung > Kidney
• Kidney > Liver > Heart > Lung
• Lung > Heart > Liver > Kidney
• Kidney > Heart > Liver > Lung

Answer :- d

8. Kenzan Method Bioprinting requires –

• Cells + Matrix
• Cell + Media
• Cells + Bioactive Factor
• All of the above
• None of the above

Answer :- a

9. The total surface area of Lung alveolar space –

• 100 m2
• 1 m2
• 100 cm2
• None of the above

Answer :- a

10. Proximal tubule bioprinting is important for –

• Heart
• Kidney
• Lung
• Liver

Answer :- b

11. Epithelial- Endothelial barrier present in –

• Kidney
• Lung
• None of the above
• All of the above

Answer :- d

12. What cell types are the unique to Heart tissue –

• Hepatocytes
• Fibroblasts
• Cardiomyocytes
• None of the above

Answer :- c

13. The major resident cells of liver are –

• Smooth Muscle cells
• Keratocytes
• Hepatocytes
• All of the above
• None of the above

Answer :- c

14. The major function of glomerulus In Kidney –

• Cellular differentiation
• Autonomous self-assembly
• Filtration of blood
• None of the above
• All of the above

Answer :- c

15. What kind of bioink is suitable for printing liver acinus –

• High viscous
• Low viscous
• Moderate viscous
• All of the above
• None of the above

Answer :- c

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Course Name	Organ Printing
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NPTEL Organ Printing Week 5 Assignment Answers 2023

1. In the context of bioprinting vasculature, what is the primary challenge associated with ensuring proper nutrient exchange and waste removal within the printed vascular network?

• Regulating blood pressure within the vessels
• Achieving precise alignment of vascular channels
• Controlling endothelial cell differentiation
• Establishing functional capillary beds

Answer :- b

2. What are the critical functions of the bioink in bioprinting vasculature, and how do these functions contribute to the formation of functional blood vessels?

• Bioink facilitates oxygen transport only; other functions are secondary
• Bioink supports cell attachment but has minimal impact on vessel formation
• Bioink provides mechanical support, guides cell behavior, and promotes angiogenesis
• Bioink accelerates blood flow within the vessels but does not influence vessel structure

Answer :- c

3. Discuss the advantages and limitations of direct printing of vasculature. How does this approach address challenges related to vessel size, cell types, and network complexity in bioprinting?

• Direct printing is limited to large vessels; small vessels are not achievable
• Direct printing offers precise control over vessel size and cell composition; network complexity is unattainable
• Direct printing is suitable for complex networks; cell viability is compromised
• Direct printing lacks control over vessel size and network complexity; it excels in cell viability

Answer :- b

4. Explain the concept of sacrificial bioinks in the indirect bioprinting of vasculature. How do sacrificial bioinks facilitate the formation of intricate vascular networks and their subsequent removal?

• Sacrificial bioinks are irrelevant in vasculature bioprinting; they hinder network formation
• Sacrificial bioinks promote vascular network degradation; they hinder vessel stability
• Sacrificial bioinks serve as temporary templates for vessel formation; they are subsequently removed
• Sacrificial bioinks enhance cell attachment to vessel walls; they remain in the construct

Answer :- c

5. In the design of a tissue-mimetic bioink for cornea bioprinting, what other tissue-like properties should the bioink possess to mimic a corneal equivalent?

• Bioink must mimic the properties of bone tissue; it has minimal impact on cornea functionality
• Bioink should replicate the stiffness of cartilage; it enhances cornea stability
• Bioink needs to resemble the mechanical properties of lung tissue; it supports cell behavior and tissue integration
• Bioink should have the consistency of adipose tissue; it accelerates cornea regeneration

Answer :- c

6. Based on the level of complexity for vasculature for bioprinting the organs can be arranged (Low to High).

• Skin>Trachea>Bladder>Kidney
• Skin>Bladder >Trachea >Kidney
• Kidney>Skin>Trachea>Bladder
• Skin> Bladder>Trachea>Kidney

Answer :- b

7. What are the different layers of bigger blood vessels-

• Tunica Intima, Tunica Media, Tunica Adventitia
• Tunica Maxima, Tunica Media, Tunica Adventitia
• Tunica Minima, Tunica Media, Tunica Adventitia
• None of the above

Answer :- a

8. Which one has very high fidelity-

• Direct 3D printing of blood vessels
• Indirect 3D printing of blood vessels
• All of the above
• None of the above

Answer :- b

9. The cornea tissue has a total no. layer-

• 4
• 5
• 3
• 6

Answer :- b

10. Corneal transparency mainly depends on-

• Cellular organization
• Orthogonal arrangement of collagen fibrils
• Matrix composition
• None of the above

Answer :- b

11. Biomimicry can be suited for corneal bioprinting to replicate the-

• Orthogonal arrangement
• Maintaining layers of cornea
• Maintaining composition
• All of the above
• None of the above

Answer :- e

12. The major resident cells of corneal stroma are-

• Smooth Muscle cells
• Keratocytes
• Epithelial cells
• All of the above
• None of the above

Answer :- b

13. The major function of Endothelial cells is-

• Cellular differentiation
• Autonomous self-assembly
• Maintaining osmotic balance
• All of the above
• None of the above

Answer :- c

14. Bioprinting technology should be capable of mimicking the vascular tress by:

• Direct 3D printing
• Indirect 3D printing
• 3D printing in support bath
• All of the above
• None of the above

Answer :- c

15. Compare the challenges and advantages of 3D bioprinting the cornea using single material bioinks versus multimaterial bioink systems. How does each approach influence the ability to replicate the intricate corneal microstructure and promote tissue function?

• Single-material bioinks hinder cornea microstructure replication; multimaterial systems support better tissue functionality
• Both single-material and multimaterial bioinks offer similar advantages in cornea bioprinting
• Single-material bioinks support better microstructure replication; multimaterial systems excel in promoting tissue functionality
• Neither single-material nor multimaterial bioinks are suitable for cornea bioprinting

Answer :- c

Course Name	Organ Printing
Category	NPTEL Assignment Answer
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NPTEL Organ Printing Week 4 Assignment Answers 2023

1. Which design approach, “bottom-up” or “top-down,” is more suitable for achieving intricate tissue microarchitecture, and how does this choice influence the potential for cellular interactions and functional integration?

1. Bottom-up approach is suitable; it enables precise microarchitecture and encourages cellular interactions
2. Top-down approach is preferable; it allows better control over cellular interactions and integration
3. Both approaches are equally effective in achieving intricate microarchitecture and cellular interactions
4. Neither approach supports intricate microarchitecture or cellular interactions effectively

Answer :- 1

2. Arrange the following organs based on the level of complexity (Low to High)-

1. Skin > Trachea > Bladder > Kidney
2. Skin > Bladder > Trachea > Kidney
3. Kidney > Skin > Trachea > Bladder
4. Skin > Bladder > Trachea > Kidney

Answer :- 1

3. What is the major challenge with bioinks for bioprinting?

1. Rheology
2. Cell Viability
3. Printability
4. All of the above
5. None of the above

Answer :- 4

4. What role does the “shear-thinning behavior” of a bioink play in the context of extrusion bioprinting?

1. It promotes rapid bioink degradation for quicker printing
2. It ensures uniform bioink viscosity throughout the printing process
3. It enables controlled flow during extrusion, allowing precise deposition
4. It enhances cell adhesion to the substrate after printing

Answer :- 3

5. The printing fidelity is very good with –

1. Low viscous bioink
2. Moderate viscous bioink
3. High viscous bioink
4. All of the above

Answer :- 3

6. Which parameter of the printing process significantly affects the “aspect ratio” of bioprinted structures, and how does it impact the construct’s mechanical stability?

1. Bioink composition; higher aspect ratio enhances stability
2. Nozzle diameter; higher aspect ratio decreases mechanical stability
3. Extrusion speed; aspect ratio has minimal impact on stability
4. Layer height; higher aspect ratio compromises mechanical stability

Answer :- 4

7. Nutrient diffusion without complete vascularization would not be a major issue for the following organ –

1. Kidney
2. Skin
3. Liver
4. Pancreas
5. Self-assembly of bioactive factors
6. None of the above

Answer :- 2

8. Requirements for direct 3D bioprinting of organs:

1. Tissue-specific bioink (bioactive as well)
2. Tissue-mimicking nano to micro architecture
3. Different cell types and extracellular matrix
4. Patterning of living cells into hydrogel tissue scaffolds
5. All of the above

Answer :- 4

9. ECM is related to –

1. Acellular components present in the tissues
2. Components present within the cells
3. Synthetic biomaterial component
4. None of the above

Answer :- 1

10. Among the following, which is a crucial challenge in bioprinting vascularized organs, and how does it affect the viability of the printed tissue?

1. Achieving cell differentiation; it hinders vascularization
2. Designing a functional vascular network; inadequate perfusion limits tissue viability
3. Selecting a suitable scaffold; it increases vascularization efficiency
4. Employing lower resolution bioprinters; it enhances vascularization complexity

Answer :- 2

11. “Scaffold-free’ version deals with

1. Self-assembling of cellular spheroids that undergo fusion and cellular organization to mimic developing tissues
2. Self-assembling of mini tissues that undergo fusion and help in developing tissues
3. Self-assembling of biomaterials scaffolds that undergo fusion and develop tissues
4. All of the above
5. None of the above

Answer :- 1

12. Self-assembly of vascular building blocks to form branched vascular networks is an example of –

1. Biomimicry
2. Autonomous self-assembly
3. Mini-tissues
4. None of the above
5. All of the above

Answer :- 3

13. In the context of bioprinting, which statement accurately reflects the complexity of replicating tissue microarchitecture and cellular heterogeneity?

1. Tissues have simpler microarchitecture, but higher cellular heterogeneity compared to whole organs
2. Tissues and whole organs have comparable complexity in both microarchitecture and cellular heterogeneity
3. Tissues possess higher microarchitectural complexity but lower cellular heterogeneity than whole organs
4. Both tissues and whole organs exhibit similar complexity, with microarchitecture and cellular heterogeneity posing unique challenges

Answer :- 3

14. What distinguishes “scaffold-based” from “scaffold-free” design approaches in bioprinting, and how does each approach impact the cellular environment and construct stability?

1. Scaffold-based approach uses natural materials only; scaffold-free approach provides mechanical support
2. Scaffold-based involves incorporating synthetic polymers; scaffold-free relies solely on cellular interactions
3. Scaffold-based uses a cell-free framework; scaffold-free relies on cell-cell interactions for mechanical stability
4. Scaffold-based offers mechanical support with materials; scaffold-free relies on cellular interactions for stability

Answer :- 4

15. Fabrication time can be enhanced without compromising resolution with the following bioink –

1. High viscous
2. Low viscous
3. Moderate viscous
4. All of the above
5. None of the above

Answer :- 1

Course Name	Organ Printing
Category	NPTEL Assignment Answer
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NPTEL Organ Printing Week 3 Assignment Answers 2023

1. Which fundamental attributes should an ideal bioink possess to support successful bioprinting of complex tissue structures?

• High electrical conductivity and resistance to temperature changes
• Biocompatibility, suitable rheological properties, and support for cellular viability
• Bright color and luminescence for real-time visualization
• Low viscosity and rapid degradation for efficient printing
• Both c and d

Answer :- Biocompatibility, suitable rheological properties, and support for cellular viability

2. What considerations are crucial when selecting the base material for bioink formulation to ensure cell survival and tissue-specific functions?

• Optical properties and fluorescence behavior under specific wavelengths
• Economic cost and ease of mass production
• Mechanical stability, biodegradability, and resemblance to native tissue environment
• Water solubility and ease of handling in the printing process
• None of the above

Answer :- Mechanical stability, biodegradability, and resemblance to native tissue environment

3. Explain the significance of bioink biocompatibility and how it influences the cellular response and integration within bioprinted tissues.

• Bioink biocompatibility is negligible in bioprinting; cell viability is usually dependent on cell type
• Biocompatibility affects bioink color and opacity; it doesn’t impact cellular behavior
• Bioink biocompatibility can yield cell proliferation; non-biocompatible bioinks hinder cell growth
• Biocompatible bioinks ensures cell survival and function, supporting tissue regeneration
• Both a and b

Answer :- Biocompatible bioinks ensures cell survival and function, supporting tissue regeneration

4. Consider the role of cell-laden bioinks in single-material and multimaterial bioink systems for bioprinting. How can these bioinks be engineered to support specific tissue functions and interactions within a complex tissue construct?

• Cell-laden bioinks are unnecessary for bioprinting; scaffolds alone are sufficient
• Cell-laden bioinks enhance structural integrity but hinder cell differentiation
• Cell-laden bioinks facilitate cell communication and tissue maturation in both systems
• Single-material bioinks rely on cell-laden bioinks, while multimaterial systems do not

Answer :- Cell-laden bioinks facilitate cell communication and tissue maturation in both systems

5. The inkjet bioprinting technique requires –

Low viscous bioink
Moderate viscous bioink
High viscous bioink
All of the above

Answer :- Low viscous bioink

6. Highly viscous bioink –

• Maintains the initial shape after deposition
• Allows deformation of the printed structure
• Facilitates collapsing of the structure
• None of the above

Answer :- Maintains the initial shape after deposition

7. What is the challenge with bioinks with dissimilar swelling behavior?

• Deformation of the structure
• Disintegration of the structure
• Stability of the structure
• All of the above
• None of the above

Answer :- All of the above

8. Which factor is critical for the success of a bioink in bioprinting?

• Color and appearance
• Viscosity and printability
• Biodegradability and disposal
• Fluorescence and luminescence
• All of the above

Answer :- Viscosity and printability

9. The printing fidelity is very good with –

• Low viscous bioink
• Moderate viscous bioink
• High viscous bioink
• All of the above

Answer :- High viscous bioink

10. Risk of laser exposure is associated with what kind of crosslinking –

• Physical crosslinking
• Chemical crosslinking
• Photo crosslinking
• All of the above
• Both b and c

Answer :- Photo crosslinking

11. What is the purpose of crosslinking in the context of hydrogel-based bioinks?

• To increase the fluidity of the bioink
• To enhance the transparency of the printed structure
• To improve the biocompatibility of the hydrogel
• To stabilize the printed structure and maintain its shape
• All of the above

Answer :- To stabilize the printed structure and maintain its shape

12. High polymer concentrations can be restrictive environments for cell migration due to –

• Dense polymeric network
• Open porous network
• Softer microenvironment
• All of the above
• Both b and c

Answer :- Dense polymeric network

13. Shear Thinning behavior is related to –

• Increase in viscosity with increase in shear rate
• Decrease in viscosity with increase in shear rate
• No change in viscosity with increase in shear rate
• Increase in viscosity during bioprinting
• None of the above

Answer :- Decrease in viscosity with increase in shear rate

14. Which method is commonly used for crosslinking hydrogels in 3D bioprinting?

• Microwave irradiation
• Mechanical agitation
• Freezing and thawing cycles
• Chemical agents or UV light exposure
• None of the above

Answer :- Chemical agents or UV light exposure

15. Yield stress is related to –

• The critical stress that that must be overcome to initiate flow
• Polymer chains form of a fragile, physically crosslinked network
• Break down of physically crosslinked network by shear forces and reorganization of the network
• All of the above
• None of the above

Answer :-All of the above

16. Gelatin based bioink shows –

• Ionic Crosslinking
• Stereocomplex Crosslinking
• Thermal Crosslinking
• None of the above
• All of the above

Answer :- Thermal Crosslinking

17. Which crosslinking does provide better structural stability and higher mechanical property?

• Physical crosslinking
• Chemical crosslinking
• Photo crosslinking
• All of the above
• None of the above

Answer :- Chemical crosslinking

18. What advantage does a multimaterial bioink system offer over a single-material system?

• Faster printing speed
• Lower cost of production
• Ability to create complex, heterogeneous structures
• Reduced need for cell culturing
• Both c and d

Answer :- Ability to create complex, heterogeneous structures

19. Arrange the printability of a bioink having polymer with (Low to High)

• High molecular weight>Moderate molecular weight >Low molecular weight
• Low molecular weight > High molecular weight>Moderate molecular weight
• Low molecular weight >Moderate molecular weight>High molecular weight

Answer :- Low molecular weight > Moderate molecular weight > High molecular weight

20. Shear stress induced cell damage is high in

• Inkjet bioprinting
• Laser-assisted bioprinting
• Extrusion bioprinting
• All of the above
• None of the above

Answer :- Extrusion bioprinting

Course Name	Organ Printing
Category	NPTEL Assignment Answer
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NPTEL Organ Printing Week 2 Assignment Answers 2023

1. What is the main advantage of Laser-assisted Bioprinting over other bioprinting techniques?

• High printing speed for large-scale tissue constructs
• Precise control of cell placement and high cell viability
• Ability to print tissues without the need for supporting structures
• Compatibility with a wide range of bioinks, including hydrogels and polymers

Answer :- Precise control of cell placement and high cell viability.

2. How does Laser-induced Forward Transfer (LIFT) differ from traditional laser printing in Laser-assisted Bioprinting?

• LIFT uses higher laser power, leading to cell damage
• LIFT involves laser ablation of tissue for 2D printing applications
• LIFT transfers living cells without damaging them in a contact-free manner
• LIFT uses ink cartridges to dispense bioink onto the substrate

Answer :- LIFT transfers living cells without damaging them in a contact-free manner.

3. The form of material in the AFA-LIFT technique is –

• Powder
• Granules
• Filament
• Ribbon

Answer :- Ribbon

4. Which bioprinting technology provides a wide choice of materials?

• Inkjet printing
• Extrusion bioprinting
• Laser-assisted bioprinting
• All of the above

Answer :- Extrusion bioprinting

5. How does Extrusion-based Bioprinting differ from Inkjet Bioprinting in terms of bioink delivery?

• Extrusion-based Bioprinting uses continuous strands of bioink, while Inkjet Bioprinting relies on droplet ejection
• Extrusion-based Bioprinting requires contact with the substrate, while Inkjet Bioprinting is contactless
• Extrusion-based Bioprinting uses a laser to solidify the bioink, while Inkjet Bioprinting utilizes UV light
• Extrusion-based Bioprinting allows the use of multiple materials, while Inkjet Bioprinting is limited to a single bioink type

Answer :- Extrusion-based Bioprinting uses continuous strands of bioink, while Inkjet Bioprinting relies on droplet ejection.

6. Which one of bioprinters is most expensive?

• Inkjet printing
• Extrusion bioprinting
• Laser-assisted bioprinting
• All of the above

Answer :- Laser-assisted bioprinting

7. High cell densities can be bioprinted with –

• Inkjet printing
• Extrusion bioprinting
• Laser-assisted bioprinting
• All of the above

Answer:- Extrusion bioprinting

8. Complex 3D geometries can be very well printed with

• Inkjet printing
• Extrusion bioprinting
• Laser-assisted bioprinting
• All of the above

Answer :- Extrusion bioprinting

9. Low power laser pulses operating in the UV or near-UV wavelength and sacrificial energy absorbing layer made of a biopolymer instead of metals are used in –

• AFA-LIFT
• LIFT
• MAPLE DW
• BioLP

Answer :- MAPLE DW

10. 800 nm laser beam to move the cells in a liquid suspension (usually in cell media), also the laser beam is coupled with hollow optical fibers in –

• AFA-LIFT
• LG DW
• MAPLE DW
• LIFT

Answer :- LG DW

11. Biopolymer-based absorbing layer is present in –

• AFA-LIFT
• LG DW
• MAPLE DW
• LIFT

Answer :- LG DW

12. Arrange the bioprinting technologies in terms of capability of using biomaterials viscosities (Low to High)

• Inkjet bioprinting > Extrusion bioprinting > Laser-assisted bioprinting
• Inkjet bioprinting > Laser-assisted bioprinting > Extrusion bioprinting
• Extrusion bioprinting > Inkjet bioprinting > Laser-assisted bioprinting

Answer :- Inkjet bioprinting > Laser-assisted bioprinting > Extrusion bioprinting.

13. Arrange the bioprinting technologies in terms their Print speed (Low to High)

• Inkjet bioprinting > Extrusion bioprinting > Laser-assisted bioprinting
• Inkjet bioprinting > Laser-assisted bioprinting > Extrusion bioprinting
• Extrusion bioprinting > Laser-assisted bioprinting > Inkjet bioprinting

Answer :- Inkjet bioprinting > Laser-assisted bioprinting > Extrusion bioprinting.

14. What is the main role of the support bath in 3D Bioprinting?

To provide structural integrity to the printed tissue construct
To prevent cross-contamination between different bioinks
To act as a barrier for maintaining a sterile bioprinting environment
To provide mechanical support and reduce the effects of gravity during printing

Answer :- To provide mechanical support and reduce the effects of gravity during printing.

15. Which factor should be primarily considered when selecting the optimal support bath for a specific bioprinting application?

• The bath’s ability to dissolve in various solvents and media
• The color and transparency of the support bath
• The density and melting point of the support bath material
• The printing temperature required for the chosen bioink

Answer :- The printing temperature required for the chosen bioink.

16. In 3D bioprinting using a support bath, what is the role of sacrificial materials?

• To act as a buffer to control pH during the printing process
• To serve as a nutrient-rich medium for cell growth
• To provide structural support during printing and dissolve post-printing
• To enhance cell adhesion to the substrate and prevent detachment

Answer :- To provide structural support during printing and dissolve post-printing.

17. What distinguishes Drop-on-Demand (DOD) Bioprinting from Continuous Inkjet (CIJ) Bioprinting?

• DOD Bioprinting uses a single bioink type, while CIJ Bioprinting allows for multiple materials
• CIJ Bioprinting requires contact with the substrate, while DOD Bioprinting is non-contact
• DOD Bioprinting prints continuous strands of bioink, while CIJ Bioprinting prints individual droplets
• CIJ Bioprinting achieves higher printing speeds compared to DOD Bioprinting

Answer :- DOD Bioprinting prints continuous strands of bioink, while CIJ Bioprinting prints individual droplets.

18. What role does the “ribbon” play in Laser-assisted Bioprinting?

• It is a specialized nozzle that deposits the bioink on the substrate
• It acts as a transfer medium for cells and biomaterials during the printing process
• It supports the 3D printed tissue construct during post-printing handling
• It is a laser-scanning component that controls the spatial arrangement of the bioink

Answer :- It acts as a transfer medium for cells and biomaterials during the printing process.

19. Most control over cell distribution within the printed tissue construct?

• Inkjet printing
• Extrusion bioprinting
• Laser-assisted bioprinting
• None of the above

Answer :- Laser-assisted bioprinting

20. A tissue engineering team aims to create a bioartificial liver using Extrusion Bioprinting. What makes Extrusion Bioprinting suitable for this application?

• Capability to print miniature functional liver lobules
• Compatibility with metallic inks for liver support structures
• High printing speed for large-scale liver constructs
• Ability to print conductive materials for liver-electrode interfaces

Answer :- Capability to print miniature functional liver lobules

NPTEL Organ Printing Week 1 Assignment Answers 2023

1. What makes 3D bioprinting different from traditional tissue engineering techniques?

• 3D bioprinting only uses biological cells as building blocks
• 3D bioprinting does not require the use of scaffolds
• 3D bioprinting is a faster process with immediate results
• 3D bioprinting allows for precise spatial arrangement of cells and biomaterials

Answer :- 3D bioprinting allows for precise spatial arrangement of cells and biomaterials.

Traditional tissue engineering techniques typically involve growing cells on scaffolds in a controlled environment to create functional tissue. In contrast, 3D bioprinting is a more advanced method that enables the precise placement of cells, biomaterials, and growth factors in a layer-by-layer fashion to create complex 3D structures. This precision in spatial arrangement is a key differentiator of 3D bioprinting compared to traditional methods, and it has the potential to mimic the intricate architecture of natural tissues more accurately.

2. Which of the following best defines tissue engineering?

• The process of creating artificial organs for transplantation
• The use of nanotechnology to repair damaged tissues
• The application of engineering and biological principles to develop functional tissues
• The study of tissue structure under a microscope

Answer :- The application of engineering and biological principles to develop functional tissues.

Tissue engineering involves combining principles from both engineering and biology to design and develop functional tissue constructs that can replace, repair, or enhance damaged or diseased tissues in the human body. This field aims to create artificial tissues and organs for transplantation or to facilitate tissue repair and regeneration.

3. Which of the following is NOT a key component of tissue engineering?

• Scaffold or framework for tissue support
• Growth factors and signaling molecules
• Biodegradable materials for implantation
• Antibiotics for preventing infections

Answer :- Antibiotics for preventing infections.

While antibiotics can play a role in preventing infections associated with tissue engineering procedures, they are not a key component of tissue engineering itself. The main components of tissue engineering include:

Scaffold or framework for tissue support: This provides structural support for cells to grow and organize into functional tissue.

Growth factors and signaling molecules: These molecules are used to guide cell behavior, promote cell proliferation, and encourage tissue regeneration.

Biodegradable materials for implantation: Biodegradable materials are often used to create scaffolds that degrade over time as the tissue regenerates, eliminating the need for surgical removal.

4. Which type of bioink is commonly used in inkjet bioprinting?

• Plastic-based bioinks
• Synthetic polymers
• Hydrogels and cell-laden solutions
• Metal-based inks

Answer :- Hydrogels and cell-laden solutions

5. Which one is true for inkjet printing?

• Non-contact
• High-throughput
• High-resolution
• All of the above
• None of the above

Answer :- All of the above.

Inkjet printing, including bioprinting, typically offers the following characteristics:

Non-contact: Inkjet printing is a non-contact printing technique where droplets of ink (or bioink in bioprinting) are ejected from a print head without physically touching the substrate. This allows for precise deposition without damaging delicate materials.

High-throughput: Inkjet printing can be high-throughput, meaning it can rapidly deposit multiple droplets of ink or bioink in a short amount of time, which is beneficial for creating complex structures efficiently.

High-resolution: Inkjet printing can achieve high-resolution printing, allowing for the precise placement of droplets with fine control over the printed pattern. This is important for creating detailed and accurate structures.

6. The preprocessing step of bioprinting involves the following.

• Preparation of bioink
• Making the CAD model
• Bioprinting of 3D structure
• Incubation of the printed construct by providing all necessary conditions

Answer :- Making the CAD model.

Before the actual bioprinting process begins, a Computer-Aided Design (CAD) model of the desired 3D structure is created. This CAD model serves as a digital blueprint that guides the bioprinter in depositing the bioink layer by layer to build the intended tissue or structure. The preparation of the bioink and other steps typically follow the CAD model creation during the bioprinting workflow.

7. The processing step of bioprinting involves the following.

• Preparation of bioink
• Making the CAD model
• Bioprinting of 3D structure
• Incubation of the printed construct by providing all necessary conditions

Answer :- Bioprinting of 3D structure.

8. The post-processing step of bioprinting involves the following.

• Preparation of bioink
• Making the CAD model
• Bioprinting of 3D structure
• Incubation of the printed construct by providing all necessary conditions

Answer :- Incubation of the printed construct by providing all necessary conditions.

9. Which bioprinting technology has the following features – Drop-on-demand and non-contact material delivery

Extrusion-based bioprinting
Inkjet-based bioprinting
Laser-induced bioprinting
All of the above
None of the above

Answer :- Inkjet-based bioprinting

10. Biopaper is used for one of the bioprinting technology.

• Extrusion-based bioprinting
• Inkjet-based bioprinting
• Laser-induced bioprinting
• All of the above
• None of the above

Answer :- Inkjet-based bioprinting

11. The inkjet bioprinter can handle the following viscosity range.

High viscosity
Moderate viscosity
Low viscosity
All of the above

Answer :- Low viscosity

12. Which bioprinting technique can also be called as droplet-based bioprinting?

• Extrusion-based bioprinting
• Inkjet-based bioprinting
• Laser-induced bioprinting
• All of the above
• None of the above

Answer :- Inkjet-based bioprinting

13. The raw materials for bioprinting are the following.

Cells
Biomaterials
Bioactive factors
All of the above
None of the above

Answer :- All of the above.

The raw materials for bioprinting typically include:

Cells: Living cells are a crucial component in bioprinting. These cells can be sourced from various tissues and organs and are often used to create functional tissues and structures.

Biomaterials: Biomaterials serve as the scaffolds or matrices that provide structural support for the printed cells. These biomaterials can be natural or synthetic and should be biocompatible and suitable for cell growth and attachment.

Bioactive factors: Bioactive factors such as growth factors, cytokines, and signaling molecules are used to guide cell behavior, promote tissue regeneration, and enhance the functionality of the printed constructs.

14. Choice of a suitable bioprinting technique is highly dependent on the following.

• Desired application
• Biomaterial formulation
• Cell types
• All of the above

Answer :- All of the above.

15. What is the advantage of using inkjet bioprinting in tissue engineering?

It allows for the printing of electronics within the tissue structures
It provides a faster printing speed compared to other bioprinting techniques
It does not require any living cells, making it easier to handle
It offers high precision and the ability to create complex tissue architectures

Answer :- It offers high precision and the ability to create complex tissue architectures.

Course Name	Organ Printing
Category	NPTEL Assignment Answer
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