Q.1 What is the primary purpose of a scaffold in tissue engineering?
To provide electrical signals to cells
To act as a 3D framework for cell attachment
To replace the need for growth factors
To serve as a nutrient reservoir
Explanation - Scaffolds offer a physical structure that supports cell adhesion, proliferation, and organization into tissues.
Correct answer is: To act as a 3D framework for cell attachment
Q.2 Which material is commonly used for biodegradable polymer scaffolds?
Polystyrene
Polylactic acid (PLA)
Polytetrafluoroethylene (PTFE)
Polyethylene terephthalate (PET)
Explanation - PLA degrades safely in the body, making it a frequent choice for temporary tissue scaffolds.
Correct answer is: Polylactic acid (PLA)
Q.3 In tissue engineering, what role does a bioreactor play?
Providing structural support
Generating electrical stimulation
Controlling mechanical and chemical environment
Replacing the scaffold material
Explanation - Bioreactors supply nutrients, remove waste, and apply mechanical forces to guide tissue development.
Correct answer is: Controlling mechanical and chemical environment
Q.4 What is the typical pore size range for vascularized tissue scaffolds?
1–5 µm
10–50 µm
100–200 µm
500–1000 µm
Explanation - Pores of 100–200 µm balance cell infiltration with mechanical integrity for blood vessel formation.
Correct answer is: 100–200 µm
Q.5 Which growth factor is essential for bone tissue engineering?
VEGF
IGF-1
BMP-2
EGF
Explanation - Bone Morphogenetic Protein‑2 strongly promotes osteogenic differentiation of stem cells.
Correct answer is: BMP-2
Q.6 What does the term 'mechanobiology' refer to in tissue engineering?
The study of chemical signals in cells
The influence of mechanical forces on biological processes
The electrical stimulation of tissues
The genetic manipulation of cells
Explanation - Mechanobiology examines how forces like tension or compression affect cell behavior and tissue formation.
Correct answer is: The influence of mechanical forces on biological processes
Q.7 Which fabrication technique uses a laser to carve microchannels into a scaffold?
Electrospinning
Stereolithography
Laser sintering
3D bioprinting
Explanation - Laser sintering fuses powdered material and can pattern precise micro‑channels for vascular networks.
Correct answer is: Laser sintering
Q.8 Why is a porous scaffold necessary for chondrocyte cultures?
To increase scaffold stiffness
To allow nutrient diffusion and waste removal
To reduce scaffold cost
To prevent cell adhesion
Explanation - Porosity lets oxygen, glucose, and metabolic by‑products travel, sustaining cartilage cells.
Correct answer is: To allow nutrient diffusion and waste removal
Q.9 What is the main advantage of using decellularized extracellular matrix (dECM) as a scaffold?
It is easier to sterilize
It has inherent bioactivity and native protein composition
It is completely synthetic
It is cheaper than synthetic polymers
Explanation - dECM retains natural growth factors and structural cues that guide cell behavior.
Correct answer is: It has inherent bioactivity and native protein composition
Q.10 In electrospinning, what is the role of the electric field?
To heat the polymer solution
To orient the fibers and create a nanofiber mesh
To chemically crosslink the scaffold
To sterilize the material
Explanation - The field draws polymer jets into fine fibers, producing a porous, high‑surface‑area mesh.
Correct answer is: To orient the fibers and create a nanofiber mesh
Q.11 Which type of cell is most commonly used for generating engineered cardiac tissue?
Hepatocytes
Neurons
Cardiomyocytes from induced pluripotent stem cells (iPSCs)
Osteoblasts
Explanation - iPSC‑derived cardiomyocytes can form beating tissue constructs for heart repair.
Correct answer is: Cardiomyocytes from induced pluripotent stem cells (iPSCs)
Q.12 What does the acronym 'GMP' stand for in the context of tissue engineering production?
Genetically Modified Product
Good Manufacturing Practice
General Medical Procedure
Growth Matrix Protein
Explanation - GMP ensures products are consistently produced and controlled according to quality standards.
Correct answer is: Good Manufacturing Practice
Q.13 Why are microfluidic devices useful in organ‑on‑chip models?
They increase scaffold stiffness
They replicate blood flow and shear stress
They provide electrical stimulation
They are cheaper than bioreactors
Explanation - Microfluidics mimic physiological fluid dynamics, essential for mimicking organ functions.
Correct answer is: They replicate blood flow and shear stress
Q.14 Which surface modification enhances fibroblast attachment on titanium implants?
Hydrophobic coating
Alkali activation
Polystyrene grafting
Silver nanoparticles
Explanation - Alkali treatment creates a porous oxide layer that improves cell adhesion.
Correct answer is: Alkali activation
Q.15 What is the purpose of crosslinking in collagen scaffolds?
To make them hydrophilic
To increase mechanical strength and reduce degradation rate
To sterilize them
To change their color
Explanation - Crosslinking links collagen fibrils, enhancing structural stability and longevity.
Correct answer is: To increase mechanical strength and reduce degradation rate
Q.16 Which imaging technique is commonly used to monitor scaffold degradation in vivo?
Ultrasound
MRI
X-ray fluoroscopy
PET
Explanation - MRI can track contrast agents within degrading scaffolds without ionizing radiation.
Correct answer is: MRI
Q.17 What does the term 'biocompatibility' describe?
The scaffold's electrical conductivity
The material's ability to withstand high temperatures
The ability of the material to interact without adverse reactions in the body
The scaffold's color stability
Explanation - Biocompatibility ensures that implanted materials do not provoke harmful immune responses.
Correct answer is: The ability of the material to interact without adverse reactions in the body
Q.18 In tissue engineering, what does 'in vitro' refer to?
In a living organism
In a controlled lab environment outside the body
Inside a computer simulation
Within a natural environment
Explanation - In vitro experiments are conducted in test tubes, dishes, or bioreactors, not in living organisms.
Correct answer is: In a controlled lab environment outside the body
Q.19 Which cell surface marker indicates mesenchymal stem cells (MSCs)?
CD34
CD45
CD73
CD3
Explanation - CD73 is a typical surface protein expressed on MSCs used for identification.
Correct answer is: CD73
Q.20 What is the main challenge when engineering large tissue constructs?
High electrical conductivity
Limited nutrient diffusion
Excessive cell adhesion
Overly high porosity
Explanation - Large constructs risk necrosis due to insufficient oxygen and nutrient transport to inner cells.
Correct answer is: Limited nutrient diffusion
Q.21 Which technique is used to align collagen fibers within a scaffold?
Freeze-drying
Magnetic alignment
Acid etching
Laser ablation
Explanation - Applying a magnetic field during fabrication or crosslinking can orient collagen fibers for anisotropic tissues.
Correct answer is: Magnetic alignment
Q.22 What does the 'S' in 'SDF-1' stand for?
Stromal
Sulfate
Signal
Sodium
Explanation - SDF‑1 means Stromal cell‑derived factor‑1, a chemokine attracting stem cells to injury sites.
Correct answer is: Stromal
Q.23 Which property is NOT desirable for a scaffold used in bone tissue engineering?
High compressive strength
Biodegradability
Low stiffness
Osteoconductivity
Explanation - Bone scaffolds require sufficient stiffness to support load; low stiffness would collapse under force.
Correct answer is: Low stiffness
Q.24 What role does nitric oxide play in engineered blood vessels?
Provides structural support
Inhibits smooth muscle proliferation
Acts as a scaffold material
Provides electrical conductivity
Explanation - NO promotes vasodilation and reduces restenosis by preventing excessive smooth muscle growth.
Correct answer is: Inhibits smooth muscle proliferation
Q.25 Which of the following is a common cell source for engineered skin?
Neurons
Keratinocytes
Myocytes
Adipocytes
Explanation - Keratinocytes form the outer epidermal layer, essential for skin regeneration.
Correct answer is: Keratinocytes
Q.26 Why is 3D bioprinting advantageous for organ fabrication?
It eliminates the need for bioreactors
It allows precise placement of multiple cell types
It makes the process completely automated
It reduces scaffold stiffness
Explanation - Bioprinting can layer different cells in spatial patterns mimicking natural tissue architecture.
Correct answer is: It allows precise placement of multiple cell types
Q.27 Which scaffold property influences cell migration speed?
Color
Surface roughness
Electrical resistance
Thermal conductivity
Explanation - Rougher surfaces provide more attachment sites, facilitating faster cell migration.
Correct answer is: Surface roughness
Q.28 What is a key benefit of using hydrogels in tissue engineering?
High mechanical stiffness
High electrical conductivity
High water content mimicking natural extracellular matrix
Increased thermal insulation
Explanation - Hydrogels create a hydrated environment similar to many soft tissues, supporting cell viability.
Correct answer is: High water content mimicking natural extracellular matrix
Q.29 Which electrical stimulation parameter is critical for myoblast differentiation?
Pulse frequency
Ambient temperature
Light intensity
Scaffold color
Explanation - Specific frequencies promote myogenic signaling pathways, enhancing muscle cell differentiation.
Correct answer is: Pulse frequency
Q.30 What does the term 'osteogenic' refer to?
Bone-forming
Blood-forming
Muscle-forming
Nerve-forming
Explanation - Osteogenic indicates the capacity to generate bone tissue.
Correct answer is: Bone-forming
Q.31 Which property of a scaffold is most important for ligament engineering?
High porosity
High tensile strength
Electrical conductivity
Biodegradability
Explanation - Ligaments endure high pulling forces; scaffolds must resist tensile loads to function properly.
Correct answer is: High tensile strength
Q.32 Which of the following is NOT a typical cell type used in cardiac patches?
Cardiomyocytes
Fibroblasts
Chondrocytes
Endothelial cells
Explanation - Chondrocytes form cartilage; they are irrelevant for heart tissue engineering.
Correct answer is: Chondrocytes
Q.33 Which device can deliver electrical cues to a cell culture in a bioreactor?
Centrifuge
Electroconductive scaffold
Incubator
pH meter
Explanation - Conductive scaffolds conduct external electrical stimuli directly to embedded cells.
Correct answer is: Electroconductive scaffold
Q.34 What is the primary goal of using a growth factor gradient in a scaffold?
To increase scaffold stiffness
To direct stem cell migration and differentiation spatially
To reduce cost
To enhance color uniformity
Explanation - Gradients mimic natural tissue development cues, guiding cells to specific fates.
Correct answer is: To direct stem cell migration and differentiation spatially
Q.35 Which scaffold material is known for its excellent electrical conductivity?
Polycaprolactone (PCL)
Gold nanoparticles
Collagen
Alginate
Explanation - Gold offers superior conductivity, useful for electrically active tissues like nerve or muscle.
Correct answer is: Gold nanoparticles
Q.36 How does shear stress influence endothelial cells in a bioreactor?
It causes them to detach
It promotes alignment and maturation
It has no effect
It degrades the scaffold
Explanation - Physiological shear drives endothelial cells to align, improving vessel functionality.
Correct answer is: It promotes alignment and maturation
Q.37 What is the advantage of using a composite scaffold (e.g., hydroxyapatite + PCL)?
Simplified manufacturing
Improved mechanical and bioactivity balance
Higher electrical resistance
Lower porosity
Explanation - Combining materials leverages strengths: PCL provides flexibility; HA enhances bone bonding.
Correct answer is: Improved mechanical and bioactivity balance
Q.38 Which method measures scaffold degradation rate in vitro?
Differential scanning calorimetry
Weight loss assay
Mass spectrometry
Fluorescence microscopy
Explanation - Periodic weighing shows mass loss, indicating material breakdown over time.
Correct answer is: Weight loss assay
Q.39 Which mechanical test is used to assess scaffold elasticity?
Tensile test
Compression test
Bending test
Hardness test
Explanation - Tensile testing measures elongation and modulus, reflecting scaffold elasticity.
Correct answer is: Tensile test
Q.40 In tissue engineering, what does 'bioprinting resolution' refer to?
The number of cells per unit volume
The smallest structural feature that can be printed
The speed of printing
The color accuracy
Explanation - Higher resolution allows finer control over scaffold microarchitecture and cell placement.
Correct answer is: The smallest structural feature that can be printed
Q.41 Why is a porous scaffold beneficial for neural tissue engineering?
It reduces scaffold weight
It allows nutrient and waste diffusion while supporting axonal growth
It increases electrical resistance
It blocks cell migration
Explanation - Neural tissues need diffusion pathways and guidance cues for regeneration.
Correct answer is: It allows nutrient and waste diffusion while supporting axonal growth
Q.42 Which surface modification promotes endothelialization of cardiovascular implants?
Coating with fibronectin
Polishing the surface
Applying a hydrophobic layer
Adding a metallic coating
Explanation - Fibronectin enhances endothelial cell adhesion and proliferation on implant surfaces.
Correct answer is: Coating with fibronectin
Q.43 Which of the following is a key requirement for a scaffold used in liver tissue engineering?
High electrical conductivity
High oxygen permeability
Low porosity
Acidic pH
Explanation - Liver cells need ample oxygen; scaffolds must allow gas diffusion.
Correct answer is: High oxygen permeability
Q.44 What does a 'hydrophilic' scaffold surface encourage?
Reduced protein adsorption
Increased cell attachment
Higher mechanical strength
Lower biodegradability
Explanation - Hydrophilic surfaces attract water molecules, enhancing protein and cell adhesion.
Correct answer is: Increased cell attachment
Q.45 Which technique is used to create a lattice structure in a scaffold?
3D printing
Electrospinning
Solvent casting
Freeze-drying
Explanation - Additive manufacturing builds precise lattice geometries layer by layer.
Correct answer is: 3D printing
Q.46 What does 'biomimicry' mean in scaffold design?
Using animal parts directly
Imitating natural tissue properties
Using synthetic materials only
Reducing cost of production
Explanation - Biomimicry replicates the structure, mechanics, and chemistry of native tissues.
Correct answer is: Imitating natural tissue properties
Q.47 Which parameter is NOT directly measured during a cell viability assay?
Metabolic activity
DNA synthesis
Cell membrane integrity
Electrical conductivity
Explanation - Viability tests focus on metabolic or membrane health, not conductivity.
Correct answer is: Electrical conductivity
Q.48 What is the function of a 'cell‑seeded' scaffold?
To provide nutrients to the scaffold
To host cells for subsequent tissue formation
To degrade faster
To become electrically conductive
Explanation - Seeding cells onto scaffolds initiates tissue development in engineered constructs.
Correct answer is: To host cells for subsequent tissue formation
Q.49 Which imaging method is most suitable for visualizing scaffold microarchitecture?
X-ray computed tomography (CT)
MRI
Ultrasound
Photography
Explanation - CT provides high‑resolution 3D images of scaffold pores and structure.
Correct answer is: X-ray computed tomography (CT)
Q.50 Which cell signaling pathway is commonly activated by mechanical strain in bone tissue?
Wnt/β‑catenin
Notch
JAK/STAT
MAPK/ERK
Explanation - Mechanical loading stimulates Wnt signaling, promoting osteogenesis.
Correct answer is: Wnt/β‑catenin
Q.51 What is the typical pore interconnectivity requirement for soft tissue scaffolds?
10–20%
30–50%
60–80%
90–100%
Explanation - High interconnectivity ensures efficient nutrient and waste transport in soft tissues.
Correct answer is: 60–80%
Q.52 Which of the following is a major barrier to vascularized tissue engineering?
Scaffold transparency
Rapid scaffold degradation
Insufficient immune response
Lack of blood vessel formation
Explanation - Without a vascular network, large tissues cannot receive adequate oxygen and nutrients.
Correct answer is: Lack of blood vessel formation
Q.53 Which process is used to sterilize polymeric scaffolds without damaging their structure?
Gamma irradiation
Autoclaving
Boiling
Dry heat
Explanation - Gamma rays sterilize effectively while preserving polymer integrity.
Correct answer is: Gamma irradiation
Q.54 What is the primary advantage of using decellularized matrices over synthetic scaffolds?
Lower cost
Better mechanical strength
Inherent bioactivity and native composition
Higher electrical conductivity
Explanation - Decellularized ECM provides natural cues for cell attachment and differentiation.
Correct answer is: Inherent bioactivity and native composition
Q.55 Which technique allows simultaneous printing of cells and biomaterial?
Microfluidic perfusion
Inkjet bioprinting
Electrospinning
Laser sintering
Explanation - Inkjet bioprinters deposit bio‑inks containing cells onto scaffolds.
Correct answer is: Inkjet bioprinting
Q.56 What is the main purpose of using a 'cell‑free' scaffold in regenerative medicine?
To be implanted without any cells
To recruit host cells to regenerate tissue
To serve as a drug delivery system
To be used as a scaffold for in vitro studies only
Explanation - Cell‑free scaffolds rely on host cell migration and differentiation for tissue repair.
Correct answer is: To recruit host cells to regenerate tissue
Q.57 Which factor does NOT influence scaffold degradation rate?
Material composition
pH of the environment
Presence of enzymes
Ambient light exposure
Explanation - Light rarely affects polymer degradation compared to chemical and enzymatic conditions.
Correct answer is: Ambient light exposure
Q.58 Why are silk fibroin scaffolds used in nerve regeneration?
They are electrically conductive
They are biodegradable and support axonal growth
They are magnetic
They have high thermal conductivity
Explanation - Silk fibroin provides a biocompatible, porous environment conducive to nerve regeneration.
Correct answer is: They are biodegradable and support axonal growth
Q.59 What does 'anisotropy' refer to in the context of scaffold mechanics?
Uniform properties in all directions
Directional dependence of mechanical properties
Non‑degradable material
Random pore orientation
Explanation - Anisotropic scaffolds mimic tissues like muscle or tendon that have orientation‑dependent strength.
Correct answer is: Directional dependence of mechanical properties
Q.60 Which parameter is essential when assessing scaffold porosity?
Total pore volume
Electrical conductivity
Surface roughness
Color
Explanation - Pore volume determines the scaffold’s ability to accommodate cells and facilitate transport.
Correct answer is: Total pore volume
Q.61 What is the benefit of incorporating growth factor‑loaded microparticles in a scaffold?
Immediate release of all factors
Sustained, localized delivery of signaling molecules
Reduced scaffold porosity
Increased electrical conductivity
Explanation - Microparticles protect growth factors and release them over time at the target site.
Correct answer is: Sustained, localized delivery of signaling molecules
Q.62 Which property is crucial for a scaffold used in tendon repair?
High compressive modulus
High tensile modulus
Low porosity
Electrical insulation
Explanation - Tendons endure tensile loads; scaffolds must mimic their stiffness.
Correct answer is: High tensile modulus
Q.63 What does 'in situ tissue engineering' involve?
Engineering tissue entirely in a lab
Injecting a scaffold into the body to heal tissue
Using natural tissues without scaffolds
Creating tissues only in a petri dish
Explanation - In situ approaches allow the scaffold to integrate and promote regeneration in its native environment.
Correct answer is: Injecting a scaffold into the body to heal tissue
Q.64 Which electrical parameter is used to stimulate cardiac cells in vitro?
Pulse amplitude
Scaffold thickness
Ambient temperature
Light wavelength
Explanation - Adjusting amplitude influences the strength of electrical signals delivered to cardiomyocytes.
Correct answer is: Pulse amplitude
Q.65 What is a common method to assess scaffold hydrophilicity?
Contact angle measurement
X‑ray diffraction
Thermogravimetric analysis
Fourier-transform infrared spectroscopy
Explanation - Measuring how a water droplet spreads indicates surface hydrophilicity.
Correct answer is: Contact angle measurement
Q.66 Which cell type is often used as a model for osteogenic differentiation?
Human mesenchymal stem cells (hMSCs)
Human epidermal keratinocytes
Human hepatocytes
Human fibroblasts
Explanation - hMSCs can differentiate into osteoblasts, making them a standard osteogenic model.
Correct answer is: Human mesenchymal stem cells (hMSCs)
Q.67 Which analytical technique measures the mechanical stiffness of a hydrogel?
Rheology
Mass spectrometry
UV–Vis spectroscopy
Dynamic light scattering
Explanation - Rheology assesses viscoelastic properties, revealing hydrogel stiffness.
Correct answer is: Rheology
Q.68 What does a 'bioactive' scaffold mean?
It is biodegradable
It actively stimulates cell functions
It is electrically conductive
It is transparent
Explanation - Bioactive materials promote cell adhesion, proliferation, and differentiation.
Correct answer is: It actively stimulates cell functions
Q.69 Which fabrication approach uses a pre‑gel solution that cross‑links upon light exposure?
Electrospinning
Stereolithography
Freeze‑drying
Electro‑spinning
Explanation - Light‑curable hydrogels polymerize in desired 3D shapes during stereolithographic printing.
Correct answer is: Stereolithography
Q.70 Why is scaffold stiffness important for chondrocyte differentiation?
Higher stiffness encourages chondrocyte apoptosis
Optimal stiffness mimics cartilage mechanics, promoting differentiation
Stiffness has no effect on chondrocytes
Lower stiffness prevents cell attachment
Explanation - Chondrocytes respond to matrix stiffness; a suitable range drives cartilage formation.
Correct answer is: Optimal stiffness mimics cartilage mechanics, promoting differentiation
Q.71 Which term describes the capacity of a scaffold to support cell migration from surrounding tissue?
Cell adhesion
Cell migration support
Cell recruitment
Cell retention
Explanation - Scaffolds that recruit host cells enable natural tissue regeneration.
Correct answer is: Cell recruitment
Q.72 What is a 'cell‑laden hydrogel' used for?
Mechanical support only
Drug delivery only
Simultaneous cell encapsulation and tissue engineering
Electrical insulation
Explanation - Cell‑laden hydrogels provide a 3D environment for cells to grow and form tissues.
Correct answer is: Simultaneous cell encapsulation and tissue engineering
Q.73 Which parameter is NOT directly controlled by a bioreactor?
Oxygen tension
Mechanical strain
Ambient light
Nutrient perfusion
Explanation - Bioreactors regulate gas, flow, and forces; light is usually incidental.
Correct answer is: Ambient light
Q.74 Which cell type is key for forming the endothelial lining of engineered vessels?
Hematopoietic stem cells
Endothelial cells
Adipocytes
Osteoclasts
Explanation - Endothelial cells line blood vessels and are critical for vascular tissue engineering.
Correct answer is: Endothelial cells
Q.75 What is the function of a 'biodegradable polymer' in scaffolds?
To remain permanently in the body
To degrade over time, leaving native tissue behind
To increase electrical resistance
To provide permanent structural support
Explanation - Biodegradability ensures the scaffold disappears as natural tissue regenerates.
Correct answer is: To degrade over time, leaving native tissue behind
Q.76 Which property is crucial for scaffolds used in bone repair?
Hydrophobicity
Osteoconductivity
Electrical insulation
Low porosity
Explanation - Osteoconductive scaffolds guide new bone growth along their structure.
Correct answer is: Osteoconductivity
Q.77 Which term describes the ability of a scaffold to mimic the mechanical behavior of native tissue?
Mechanical fidelity
Mechanical compatibility
Structural resemblance
Elastic similarity
Explanation - Mechanical fidelity ensures the scaffold behaves similarly to the target tissue under load.
Correct answer is: Mechanical fidelity
Q.78 What is a typical pore size range for skin tissue scaffolds?
1–5 µm
10–50 µm
100–200 µm
500–1000 µm
Explanation - Smaller pores support keratinocyte adhesion while allowing nutrient diffusion in skin scaffolds.
Correct answer is: 10–50 µm
Q.79 Which method can be used to produce a gradient of stiffness within a single scaffold?
Uniform mixing
Gradient polymerization
Single‑point printing
Bulk solvent casting
Explanation - Gradients can be formed by varying crosslinking or polymer concentration across the scaffold.
Correct answer is: Gradient polymerization
Q.80 What does a 'cell‑encapsulated hydrogel' primarily provide?
A 2D surface for cell attachment
A 3D microenvironment for cell survival
An electrical pathway
A rigid support
Explanation - Encapsulation protects cells and mimics natural 3D extracellular matrix.
Correct answer is: A 3D microenvironment for cell survival
Q.81 Which fabrication technique offers the highest resolution for micro‑needle arrays?
Laser sintering
Inkjet printing
Electrospinning
Stereolithography
Explanation - Laser sintering can create fine, precise micro‑structures such as micro‑needles.
Correct answer is: Laser sintering
Q.82 What is the main disadvantage of using metallic implants in tissue engineering?
They are too flexible
They lack biodegradability
They are inexpensive
They provide too many growth factors
Explanation - Metals remain permanently, potentially causing long‑term complications.
Correct answer is: They lack biodegradability
Q.83 Which component is often added to hydrogels to improve cell adhesion?
PEG
RGD peptide
Silicone
Hydroxyapatite
Explanation - RGD motifs enhance integrin‑mediated cell attachment on otherwise inert hydrogels.
Correct answer is: RGD peptide
Q.84 What does the term 'osteoinductive' refer to?
Promoting bone formation
Resisting bone resorption
Providing mechanical support
Degrading rapidly
Explanation - Osteoinductive materials actively stimulate precursor cells to become osteoblasts.
Correct answer is: Promoting bone formation
Q.85 Which parameter influences the diffusion rate of oxygen in a scaffold?
Pore size
Scaffold color
Electrical conductivity
Ambient light
Explanation - Larger pores improve oxygen diffusion, essential for cell viability.
Correct answer is: Pore size
Q.86 What does a 'hydrogel' primarily consist of?
Solid metal
Cross‑linked polymer network swollen in water
Silicon dioxide
Organic solvent
Explanation - Hydrogels are water‑rich polymeric gels forming 3D networks.
Correct answer is: Cross‑linked polymer network swollen in water
Q.87 Which property is essential for a scaffold used in neural tissue engineering?
High electrical conductivity
High compressive strength
Low porosity
High thermal resistance
Explanation - Neural tissues transmit electrical signals; conductive scaffolds support signal propagation.
Correct answer is: High electrical conductivity
Q.88 Which technique is used to create micro‑channels within a hydrogel?
Micro‑stereolithography
Freeze‑casting
Laser ablation
Electrospinning
Explanation - Laser ablation removes material to form precise channels in hydrogels.
Correct answer is: Laser ablation
Q.89 Why is a high surface area important for scaffold design?
To increase weight
To enhance cell attachment and nutrient exchange
To reduce porosity
To improve electrical insulation
Explanation - Greater surface area provides more sites for cells and facilitates mass transport.
Correct answer is: To enhance cell attachment and nutrient exchange
Q.90 Which material is commonly used for biocompatible, non‑degradable electrical contacts?
Silver
Polylactic acid (PLA)
Polyethylene glycol (PEG)
Collagen
Explanation - Silver offers high conductivity and good biocompatibility for temporary contacts.
Correct answer is: Silver
Q.91 What does 'cell seeding density' refer to?
Number of cells per volume of scaffold
Number of pores per unit area
Number of scaffold layers
Amount of growth factor added
Explanation - Seeding density determines how many cells are initially placed within the scaffold.
Correct answer is: Number of cells per volume of scaffold
Q.92 Which property is not typically measured during scaffold characterization?
Porosity
Elastic modulus
Color
Degradation rate
Explanation - Physical and chemical properties are measured; color is irrelevant to functionality.
Correct answer is: Color
Q.93 Which of the following is a challenge when scaling up tissue‑engineered organs?
Lack of scaffold materials
Difficulty achieving uniform vascularization
High scaffold cost
Low cell proliferation rates
Explanation - Large constructs require extensive blood vessel networks to sustain cell viability.
Correct answer is: Difficulty achieving uniform vascularization
Q.94 Which scaffold design promotes anisotropic mechanical properties?
Random fiber orientation
Aligned fiber architecture
Uniform pore size
Uniform material composition
Explanation - Aligned fibers create direction‑dependent stiffness, mimicking tissues like tendon.
Correct answer is: Aligned fiber architecture
Q.95 What is the advantage of using a 'dynamic culture' over static culture?
It reduces oxygen levels
It improves nutrient and waste transport
It eliminates the need for a scaffold
It decreases cell proliferation
Explanation - Dynamic flow enhances mass transfer, promoting better tissue development.
Correct answer is: It improves nutrient and waste transport
Q.96 Which term describes a scaffold that can adapt its properties over time in response to cellular activity?
Smart scaffold
Passive scaffold
Static scaffold
Fixed scaffold
Explanation - Smart scaffolds respond to stimuli, altering stiffness, degradation, or drug release.
Correct answer is: Smart scaffold
Q.97 What role does collagen type I play in bone tissue engineering?
It forms a non‑degradable core
It provides a natural protein framework
It increases scaffold conductivity
It reduces porosity
Explanation - Collagen I is a major component of bone ECM, promoting cell adhesion.
Correct answer is: It provides a natural protein framework
Q.98 Which parameter is essential for controlling the release rate of growth factors from a scaffold?
Scaffold thickness
Crosslinking density
Ambient temperature
Scaffold color
Explanation - Higher crosslinking slows degradation, extending growth factor release.
Correct answer is: Crosslinking density
Q.99 What does 'osteopromotive' mean regarding scaffold design?
It enhances bone formation
It prevents bone formation
It degrades rapidly
It is electrically insulating
Explanation - Osteopromotive scaffolds actively encourage new bone growth.
Correct answer is: It enhances bone formation
Q.100 Which technique is used to fabricate porous ceramic scaffolds?
Sintering
Electrospinning
Micro‑stereolithography
Inkjet bioprinting
Explanation - Sintering fuses ceramic particles, creating a porous ceramic scaffold.
Correct answer is: Sintering
Q.101 What is the main reason to use a composite of polymer and hydroxyapatite for bone scaffolds?
To increase electrical conductivity
To combine mechanical support with osteoconductivity
To reduce cost
To lower porosity
Explanation - Polymer provides flexibility; hydroxyapatite supports bone bonding.
Correct answer is: To combine mechanical support with osteoconductivity
Q.102 Which property of a scaffold is critical for ensuring uniform cell distribution?
High porosity
Low stiffness
Large pore size
Uniform pore size and interconnectivity
Explanation - Consistent pores prevent cell aggregation and promote even seeding.
Correct answer is: Uniform pore size and interconnectivity
Q.103 What is the main goal of incorporating vascular endothelial growth factor (VEGF) into a scaffold?
To promote bone mineralization
To encourage angiogenesis
To increase mechanical strength
To reduce scaffold stiffness
Explanation - VEGF stimulates new blood vessel growth within the scaffold.
Correct answer is: To encourage angiogenesis
Q.104 Which feature of a scaffold promotes cell infiltration into the core?
Small pore size
High interconnectivity
Rigid structure
Low surface energy
Explanation - Interconnected pores allow cells to migrate throughout the scaffold.
Correct answer is: High interconnectivity
Q.105 What does a 'bioactive glass' scaffold provide?
High mechanical strength only
Release of ions that stimulate bone growth
Electrical insulation
High hydrophobicity
Explanation - Bioactive glass releases calcium and phosphate, promoting osteogenesis.
Correct answer is: Release of ions that stimulate bone growth
Q.106 Which of the following is a method to evaluate scaffold cytotoxicity?
Live/Dead staining
X‑ray diffraction
Thermogravimetric analysis
Electrical impedance spectroscopy
Explanation - Live/Dead staining differentiates viable from non‑viable cells on a scaffold.
Correct answer is: Live/Dead staining
Q.107 Which technique allows creation of gradient pore sizes in a single scaffold?
Stereolithography with variable exposure
Uniform solvent casting
Single‑point printing
Bulk compression molding
Explanation - Adjusting exposure time during SLA creates varying pore sizes across the construct.
Correct answer is: Stereolithography with variable exposure
Q.108 What is the main function of a 'supportive matrix' in engineered tissues?
To provide electrical stimulation
To provide temporary mechanical support during tissue maturation
To serve as a permanent structure
To deliver nutrients directly
Explanation - Supportive matrices hold the shape while new tissue forms and eventually degrade.
Correct answer is: To provide temporary mechanical support during tissue maturation
Q.109 Which factor influences the viscoelastic properties of a hydrogel?
Temperature
Crosslinker concentration
Ambient light intensity
Color of the hydrogel
Explanation - Higher crosslinking increases stiffness and reduces viscoelasticity.
Correct answer is: Crosslinker concentration
Q.110 What is the main benefit of using a 'cell‑free' approach in regenerative medicine?
Immediate tissue formation
Reduced risk of immune rejection
Elimination of growth factors
Increased scaffold cost
Explanation - Without implanted cells, the risk of graft rejection is minimized.
Correct answer is: Reduced risk of immune rejection
Q.111 Which property is crucial for a scaffold used in cartilage repair?
High electrical conductivity
High compressive modulus
High porosity for nutrient diffusion
Low mechanical strength
Explanation - Cartilage experiences compressive loads; scaffolds must match this mechanical property.
Correct answer is: High compressive modulus
Q.112 Which technique is commonly used to print vascular networks within a scaffold?
Stereolithography
Electrospinning
Micro‑stereolithography
Thermal extrusion
Explanation - Micro‑stereolithography enables fine, precise micro‑vessel geometries.
Correct answer is: Micro‑stereolithography
Q.113 What does 'osteogenic differentiation' involve?
Formation of bone‑forming cells
Formation of nerve cells
Formation of skin cells
Formation of fat cells
Explanation - It is the process by which stem cells become osteoblasts that build bone.
Correct answer is: Formation of bone‑forming cells
Q.114 Which of the following is NOT a typical characteristic of a tissue‑engineered construct?
Biodegradability
Mechanical stiffness
Electrical insulation
Cellular integration
Explanation - Most constructs are designed to interact biologically, not necessarily to insulate electrically.
Correct answer is: Electrical insulation
Q.115 What is the primary benefit of using a 'multi‑layered' scaffold?
Increased weight
Enhanced mechanical strength and functional gradients
Reduced cell viability
Simplified fabrication
Explanation - Layering can mimic the hierarchical structure of native tissues.
Correct answer is: Enhanced mechanical strength and functional gradients
Q.116 Which parameter is crucial for ensuring cell survival in a 3D printed scaffold?
Print speed
Pore size and connectivity
Ambient light exposure
Color of the bio‑ink
Explanation - Adequate porosity allows nutrient and oxygen diffusion to embedded cells.
Correct answer is: Pore size and connectivity
Q.117 Which method is used to crosslink gelatin hydrogels for tissue engineering?
UV irradiation
High temperature
Magnetic field
Acidic pH
Explanation - UV light crosslinks gelatin methacrylate, forming a stable hydrogel network.
Correct answer is: UV irradiation
Q.118 What is the function of a 'growth factor reservoir' in a scaffold?
To store excess cells
To slowly release bioactive molecules
To provide mechanical support
To maintain scaffold color
Explanation - Reservoirs release growth factors over time, guiding tissue development.
Correct answer is: To slowly release bioactive molecules
Q.119 Which of these is a challenge when using natural polymers for scaffolds?
High electrical conductivity
Batch‑to‑batch variability
Low biodegradability
Low porosity
Explanation - Natural polymers can vary in composition, affecting reproducibility.
Correct answer is: Batch‑to‑batch variability
Q.120 What does a 'hydrogel’ mean in the context of tissue engineering?
A hard, non‑porous material
A soft, water‑rich polymer network
A metal alloy
A type of cell culture medium
Explanation - Hydrogels mimic soft tissue environments due to their high water content.
Correct answer is: A soft, water‑rich polymer network
Q.121 Which property of a scaffold is crucial for mimicking tendon structure?
Random pore orientation
Aligned fiber orientation
High porosity
Low mechanical strength
Explanation - Aligned fibers replicate the anisotropic strength of tendons.
Correct answer is: Aligned fiber orientation
Q.122 Which technique can be used to assess scaffold porosity in situ?
SEM imaging
Micro‑CT scanning
X‑ray diffraction
Optical microscopy
Explanation - Micro‑CT provides 3D porosity measurements within intact scaffolds.
Correct answer is: Micro‑CT scanning
Q.123 What is the primary purpose of incorporating collagen type II in cartilage scaffolds?
To increase electrical conductivity
To provide a natural cartilage matrix component
To reduce pore size
To increase scaffold stiffness
Explanation - Collagen II is the main collagen in cartilage, supporting cell attachment and matrix formation.
Correct answer is: To provide a natural cartilage matrix component
Q.124 Which factor influences the rate of cell migration within a scaffold?
Scaffold color
Pore interconnectivity
Ambient temperature
Electrical resistance
Explanation - Highly interconnected pores facilitate easier cell movement throughout the scaffold.
Correct answer is: Pore interconnectivity
Q.125 What is the main advantage of using a 'bio‑ink' containing cells for bioprinting?
It eliminates the need for a scaffold
It allows precise spatial deposition of live cells
It increases scaffold stiffness
It reduces electrical conductivity
Explanation - Cell‑laden inks enable accurate placement of different cell types within a construct.
Correct answer is: It allows precise spatial deposition of live cells
Q.126 Which property is crucial for scaffolds intended for bone marrow niche engineering?
High porosity and stiffness
Low mechanical strength
High electrical resistance
Low interconnectivity
Explanation - Bone marrow supports hematopoietic cells and requires a porous, stiff environment.
Correct answer is: High porosity and stiffness
Q.127 What does 'osteoinductive' material do?
Prevents bone formation
Promotes bone formation from progenitor cells
Increases scaffold degradation
Reduces cell adhesion
Explanation - Osteoinductive cues drive stem cells to become bone‑forming osteoblasts.
Correct answer is: Promotes bone formation from progenitor cells
Q.128 Which property is NOT a major consideration when designing a scaffold for cartilage repair?
High compressive modulus
Low pore size
High mechanical flexibility
Uniform pore distribution
Explanation - Cartilage needs larger pores for nutrient diffusion; very small pores hinder this.
Correct answer is: Low pore size
Q.129 Which technique is used to create a porous scaffold via phase separation?
Solvent casting and particulate leaching
Freeze‑casting
Electrospinning
3D printing
Explanation - Leaching particles from a polymer solution generates interconnected pores.
Correct answer is: Solvent casting and particulate leaching
Q.130 What is a key challenge in engineering large, vascularized organs?
Finding suitable scaffold colors
Ensuring uniform cell density
Achieving rapid scaffold degradation
Generating functional vasculature throughout the tissue
Explanation - Blood vessels are required to supply oxygen and nutrients to large engineered tissues.
Correct answer is: Generating functional vasculature throughout the tissue
Q.131 Which of the following is a benefit of using a 'dynamic perfusion culture'?
It reduces oxygen supply
It enhances mechanical stimulation and nutrient transport
It eliminates the need for a scaffold
It increases scaffold porosity drastically
Explanation - Perfusion provides flow‑induced shear and improved mass transfer.
Correct answer is: It enhances mechanical stimulation and nutrient transport
Q.132 Which property is crucial for nerve tissue engineering scaffolds?
High electrical conductivity
High compressive modulus
Large pore size
Low porosity
Explanation - Nerve cells communicate electrically; conductive scaffolds support signal propagation.
Correct answer is: High electrical conductivity
Q.133 What does 'bioprinting' primarily involve?
Printing purely synthetic materials
Printing living cells within a supportive bio‑ink
Printing electrical circuits
Printing non‑biological composites
Explanation - Bioprinting deposits cells along with bio‑inks to form 3D tissue constructs.
Correct answer is: Printing living cells within a supportive bio‑ink
Q.134 Which technique can provide a gradient of mechanical stiffness in a scaffold?
Uniform 3D printing
Variable crosslinking during fabrication
Single‑layer extrusion
Bulk compression molding
Explanation - Adjusting crosslink density across the scaffold creates stiffness gradients.
Correct answer is: Variable crosslinking during fabrication
Q.135 What is the role of 'PEG' in hydrogels for tissue engineering?
Provides electrical conductivity
Acts as a structural protein
Enhances mechanical strength and biocompatibility
Increases scaffold hydrophobicity
Explanation - Polyethylene glycol improves hydrogel stability and reduces protein adsorption.
Correct answer is: Enhances mechanical strength and biocompatibility
Q.136 Which property of a scaffold is most relevant for bone regeneration?
Osteoinductive capacity
Electrical resistance
Low porosity
High thermal conductivity
Explanation - Materials that actively induce bone formation enhance regeneration.
Correct answer is: Osteoinductive capacity
Q.137 Which of the following is NOT a common material for electrospun fibrous scaffolds?
Polylactic acid (PLA)
Polycaprolactone (PCL)
Hydroxyapatite
Polyethylene glycol (PEG)
Explanation - Hydroxyapatite is brittle and not typically electrospun into fibers.
Correct answer is: Hydroxyapatite
Q.138 What is the purpose of using 'spheroids' in 3D tissue constructs?
To increase scaffold stiffness
To mimic cell‑cell interactions in a compact form
To reduce nutrient diffusion
To eliminate the need for growth factors
Explanation - Spheroids provide a 3D microenvironment similar to native tissues.
Correct answer is: To mimic cell‑cell interactions in a compact form
Q.139 Which parameter is crucial for controlling the release of growth factors from a scaffold?
Scaffold thickness
Crosslink density
Ambient light intensity
Scaffold color
Explanation - Higher crosslinking slows degradation, extending growth factor release.
Correct answer is: Crosslink density
Q.140 What is the main advantage of a 'smart scaffold'?
It is static and inert
It adapts its properties in response to environmental cues
It has fixed stiffness
It is non‑degradable
Explanation - Smart scaffolds can change stiffness or release drugs dynamically.
Correct answer is: It adapts its properties in response to environmental cues
Q.141 Which of the following materials is NOT typically used for creating electroactive scaffolds?
Gold nanoparticles
Carbon nanotubes
Polylactic acid (PLA)
PEDOT:PSS
Explanation - PLA is insulating; the others conduct electricity.
Correct answer is: Polylactic acid (PLA)
Q.142 What is the significance of 'pore interconnectivity' in a scaffold?
It determines scaffold color
It affects nutrient diffusion and cell migration
It reduces scaffold stiffness
It controls scaffold electrical resistance
Explanation - Interconnected pores allow cells to spread and nutrients to reach all areas.
Correct answer is: It affects nutrient diffusion and cell migration
Q.143 Which technique can create a hydrogel with tunable stiffness?
UV crosslinking of gelatin methacrylate
Heat curing of epoxy
Solvent evaporation
Chemical bleaching
Explanation - Varying UV exposure changes crosslink density and thus hydrogel stiffness.
Correct answer is: UV crosslinking of gelatin methacrylate
Q.144 Why is 'cell migration' important in tissue engineering?
It allows cells to leave the scaffold
It promotes uniform tissue formation throughout the construct
It reduces scaffold degradation
It increases scaffold stiffness
Explanation - Migrating cells populate the scaffold, forming homogeneous tissue.
Correct answer is: It promotes uniform tissue formation throughout the construct
Q.145 Which property is most critical for scaffolds used in bone marrow stroma engineering?
High porosity and mechanical strength
Low porosity and high stiffness
High electrical resistance
Low mechanical strength
Explanation - Bone marrow niches require porous, yet strong, scaffolds to support hematopoietic cells.
Correct answer is: High porosity and mechanical strength
Q.146 Which method is used to evaluate the mechanical properties of a scaffold?
Thermal gravimetric analysis
Mechanical testing (tensile, compressive)
X‑ray diffraction
Fluorescence microscopy
Explanation - These tests measure stiffness, strength, and deformation behavior.
Correct answer is: Mechanical testing (tensile, compressive)
Q.147 What does the term 'biocompatibility' mean?
Material can be used in electronics
Material does not provoke adverse biological responses
Material is biodegradable
Material is electrically conductive
Explanation - Biocompatible materials integrate with tissue without causing inflammation.
Correct answer is: Material does not provoke adverse biological responses
Q.148 What is the main function of a scaffold in tissue engineering?
To replace the need for growth factors
To provide a structural framework for cell growth and tissue development
To act as a permanent implant
To deliver drugs to the patient
Explanation - Scaffolds support cell attachment, proliferation, and differentiation.
Correct answer is: To provide a structural framework for cell growth and tissue development
Q.149 Which of the following is NOT a typical characteristic of a tissue‑engineered construct?
Biodegradability
Mechanical strength
Electrical insulation
Cellular integration
Explanation - The construct must interact biologically; insulation is not a primary goal.
Correct answer is: Electrical insulation
Q.150 Which scaffold property is most relevant for vascular tissue engineering?
High compressive modulus
High pore interconnectivity
Low electrical conductivity
Low porosity
Explanation - Vascular constructs need interconnected pores for blood flow and cell migration.
Correct answer is: High pore interconnectivity
Q.151 Which technique is used to create a scaffold with aligned fibers?
Electrospinning
Solvent casting
Freeze‑drying
Thermal extrusion
Explanation - Electrospinning can align fibers by adjusting the collector geometry.
Correct answer is: Electrospinning
Q.152 What does 'osteoinductive' mean in scaffold design?
Promotes bone formation from progenitor cells
Prevents bone formation
Enhances scaffold degradation
Reduces cell adhesion
Explanation - It indicates the material stimulates cells to differentiate into osteoblasts.
Correct answer is: Promotes bone formation from progenitor cells
Q.153 Which of the following is a key challenge in 3D bioprinting of large tissues?
Maintaining cell viability during printing
High scaffold color
Low cell density
Simplifying scaffold design
Explanation - Shear forces and temperature can kill cells, limiting construct viability.
Correct answer is: Maintaining cell viability during printing
Q.154 Which property of a scaffold is important for supporting cartilage formation?
High compressive modulus
High porosity
High electrical resistance
Low mechanical strength
Explanation - Cartilage experiences compression; scaffolds need to match this mechanical behavior.
Correct answer is: High compressive modulus
Q.155 What is the main advantage of using a 'cell‑free' approach?
Eliminates immune rejection risks
Increases scaffold cost
Requires additional growth factors
Reduces cell viability
Explanation - Without implanted cells, the scaffold is less likely to provoke rejection.
Correct answer is: Eliminates immune rejection risks
Q.156 Which parameter is crucial for ensuring cell viability in a 3D printed scaffold?
Print speed
Pore size and connectivity
Ambient light exposure
Color of the bio‑ink
Explanation - Adequate porosity allows nutrients to reach all embedded cells.
Correct answer is: Pore size and connectivity
Q.157 Which technique is commonly used to produce a gradient of stiffness within a scaffold?
Uniform 3D printing
Variable crosslinking during fabrication
Single‑layer extrusion
Bulk compression molding
Explanation - Adjusting crosslink density creates stiffness gradients mimicking native tissue.
Correct answer is: Variable crosslinking during fabrication
Q.158 What does a 'hydrogel' provide in tissue engineering?
A rigid, non‑porous structure
A soft, water‑rich environment for cells
Electrical insulation
High mechanical strength
Explanation - Hydrogels mimic soft tissues due to high water content.
Correct answer is: A soft, water‑rich environment for cells
Q.159 Which property is crucial for nerve tissue engineering scaffolds?
High electrical conductivity
High compressive modulus
Large pore size
Low porosity
Explanation - Nerve cells require conductive environments to propagate electrical signals.
Correct answer is: High electrical conductivity
Q.160 Which technique can provide a gradient pore size in a scaffold?
Stereolithography with variable exposure
Uniform solvent casting
Single‑point printing
Bulk compression molding
Explanation - Adjusting light exposure during SLA creates varied pore sizes.
Correct answer is: Stereolithography with variable exposure
Q.161 Which of the following is a challenge in creating large tissue constructs?
Generating functional vasculature throughout the tissue
Finding suitable scaffold colors
Reducing cell proliferation
Decreasing scaffold degradation rate
Explanation - Blood vessels are needed to supply nutrients to large engineered tissues.
Correct answer is: Generating functional vasculature throughout the tissue
Q.162 What is the main function of a 'supportive matrix' in tissue engineering?
Provide temporary mechanical support during tissue maturation
Serve as a permanent structure
Deliver nutrients directly
Reduce scaffold porosity
Explanation - It holds the shape until new tissue forms and the scaffold degrades.
Correct answer is: Provide temporary mechanical support during tissue maturation
Q.163 Which property of a hydrogel is most affected by crosslinking density?
Viscoelasticity
Color
Electrical resistance
Thermal conductivity
Explanation - Crosslinking controls the gel's stiffness and deformation behavior.
Correct answer is: Viscoelasticity
Q.164 Which technique is used to create micro‑vessel networks within a scaffold?
Micro‑stereolithography
Solvent casting
Electrospinning
Thermal extrusion
Explanation - It can print fine vascular channels with high precision.
Correct answer is: Micro‑stereolithography
Q.165 What does 'osteoconductive' mean in scaffold design?
Promotes bone formation from progenitor cells
Supports bone growth along its surface
Prevents bone formation
Enhances scaffold degradation
Explanation - It provides a physical template for new bone to grow into.
Correct answer is: Supports bone growth along its surface
Q.166 Which parameter is crucial for achieving uniform cell distribution in a scaffold?
Uniform pore size and interconnectivity
High porosity only
Low stiffness
High electrical conductivity
Explanation - Even pore distribution helps cells disperse evenly throughout the scaffold.
Correct answer is: Uniform pore size and interconnectivity
Q.167 What is the main advantage of using a 'cell‑laden' hydrogel?
It eliminates the need for growth factors
It allows for immediate cell encapsulation and 3D culture
It increases scaffold stiffness
It reduces cell viability
Explanation - Cell‑laden hydrogels provide a 3D microenvironment for cells.
Correct answer is: It allows for immediate cell encapsulation and 3D culture
Q.168 Which of the following is a challenge when scaling up tissue‑engineered organs?
Generating functional vasculature throughout the tissue
Ensuring uniform cell density
Reducing scaffold degradation
Simplifying fabrication
Explanation - Large constructs need blood vessels to deliver oxygen and nutrients.
Correct answer is: Generating functional vasculature throughout the tissue
Q.169 What role does VEGF play in tissue engineering scaffolds?
Stimulates bone mineralization
Encourages angiogenesis
Increases mechanical strength
Reduces cell adhesion
Explanation - VEGF promotes blood vessel formation within the scaffold.
Correct answer is: Encourages angiogenesis
Q.170 Which material is known for its high electrical conductivity, often used in neural scaffolds?
Polyethylene glycol
Gold nanoparticles
Polylactic acid
Collagen
Explanation - Gold provides conductivity for electrical signaling in neural tissue engineering.
Correct answer is: Gold nanoparticles
Q.171 Which property of a scaffold is most relevant for cartilage repair?
High compressive modulus
High porosity and flexibility
Electrical insulation
Low mechanical strength
Explanation - Cartilage experiences compressive loads; scaffolds need similar stiffness.
Correct answer is: High compressive modulus
Q.172 What is the main advantage of using a 'bio‑ink' containing cells for bioprinting?
It eliminates the need for a scaffold
It allows precise spatial deposition of live cells
It increases scaffold stiffness
It reduces electrical conductivity
Explanation - Cell‑laden inks enable accurate placement of different cell types within a construct.
Correct answer is: It allows precise spatial deposition of live cells
Q.173 Which property is crucial for scaffolds intended for bone marrow niche engineering?
High porosity and stiffness
Low mechanical strength
High electrical resistance
Low interconnectivity
Explanation - Bone marrow niches require porous yet strong scaffolds to support hematopoietic cells.
Correct answer is: High porosity and stiffness
Q.174 What does 'osteoinductive' material do?
Prevents bone formation
Promotes bone formation from progenitor cells
Increases scaffold degradation
Reduces cell adhesion
Explanation - Osteoinductive cues drive stem cells to become bone‑forming osteoblasts.
Correct answer is: Promotes bone formation from progenitor cells
Q.175 Which technique is used to create a porous scaffold via phase separation?
Solvent casting and particulate leaching
Freeze‑casting
Electrospinning
3D printing
Explanation - Leaching particles from a polymer solution generates interconnected pores.
Correct answer is: Solvent casting and particulate leaching
Q.176 What is a key challenge in engineering large, vascularized organs?
Finding suitable scaffold colors
Ensuring uniform cell density
Achieving rapid scaffold degradation
Generating functional vasculature throughout the tissue
Explanation - Blood vessels are required to supply oxygen and nutrients to large engineered tissues.
Correct answer is: Generating functional vasculature throughout the tissue
Q.177 Which technique can provide a gradient of mechanical stiffness in a scaffold?
Variable crosslinking during fabrication
Uniform 3D printing
Single‑layer extrusion
Bulk compression molding
Explanation - Adjusting crosslink density creates stiffness gradients.
Correct answer is: Variable crosslinking during fabrication
Q.178 Which property is most relevant for scaffolds used in bone marrow stroma engineering?
High porosity and mechanical strength
Low porosity and high stiffness
High electrical resistance
Low mechanical strength
Explanation - Bone marrow niches require porous, yet strong, scaffolds to support hematopoietic cells.
Correct answer is: High porosity and mechanical strength