Q.1 What is the primary purpose of a scaffold in tissue engineering?
To provide electrical stimulation to cells
To act as a temporary matrix for cell attachment and growth
To deliver nutrients directly to the bloodstream
To replace the entire organ permanently
Explanation - A scaffold serves as a 3D framework that supports cell adhesion, proliferation, and differentiation until the newly formed tissue can sustain itself.
Correct answer is: To act as a temporary matrix for cell attachment and growth
Q.2 Which material is commonly used to make biodegradable polymeric scaffolds?
Polylactic acid (PLA)
Polytetrafluoroethylene (PTFE)
Stainless steel
Polyethylene terephthalate (PET)
Explanation - PLA is a biocompatible, biodegradable polymer widely used in tissue engineering because it degrades into lactic acid, a natural metabolite.
Correct answer is: Polylactic acid (PLA)
Q.3 Which fabrication technique uses high voltage to create nanofibers?
Mold casting
Electrospinning
Stereolithography
Laser sintering
Explanation - Electrospinning applies an electric field to produce fine polymer fibers, generating a fibrous scaffold that mimics extracellular matrix.
Correct answer is: Electrospinning
Q.4 What pore size range is generally considered optimal for bone tissue scaffolds?
5–10 micrometers
50–150 micrometers
200–500 micrometers
1–2 millimeters
Explanation - Pores in the 50–150 μm range allow vascularization and bone cell migration while maintaining mechanical strength.
Correct answer is: 50–150 micrometers
Q.5 How does electrical conductivity affect cell behavior on a scaffold?
It prevents cell attachment
It enhances osteogenic differentiation of stem cells
It degrades the scaffold faster
It has no effect on cells
Explanation - Conductive scaffolds can transmit electrical cues that stimulate stem cells to differentiate into bone cells, improving tissue regeneration.
Correct answer is: It enhances osteogenic differentiation of stem cells
Q.6 Which of the following is NOT a commonly used conductive additive in polymer scaffolds?
Graphene
Carbon nanotubes
Hydroxyapatite
Gold nanoparticles
Explanation - Hydroxyapatite is bioactive but not conductive; graphene, CNTs, and gold provide electrical conductivity.
Correct answer is: Hydroxyapatite
Q.7 What is the main advantage of using 3D bioprinting for scaffold fabrication?
It allows precise control over pore geometry and cell placement
It is cheaper than all other methods
It eliminates the need for sterilization
It uses only natural materials
Explanation - 3D bioprinting enables layer‑by‑layer deposition of bioinks, allowing complex architectures and targeted cell distribution.
Correct answer is: It allows precise control over pore geometry and cell placement
Q.8 Which electrical parameter is most relevant when designing a scaffold for nerve regeneration?
Capacitance
Impedance
Conductivity
Magnetic permeability
Explanation - Impedance determines how electrical signals propagate through the scaffold, affecting neuronal guidance and stimulation efficacy.
Correct answer is: Impedance
Q.9 Why is the degradation rate of a scaffold important?
It determines the color of the scaffold
It matches the tissue regeneration rate to avoid premature collapse or long‑term foreign body presence
It controls the scaffold’s electrical conductivity
It influences the scaffold’s magnetic properties
Explanation - A scaffold that degrades too quickly cannot support new tissue; one that degrades too slowly may inhibit integration or cause inflammation.
Correct answer is: It matches the tissue regeneration rate to avoid premature collapse or long‑term foreign body presence
Q.10 What is a key challenge when incorporating electrical stimulation into tissue scaffolds?
Keeping the scaffold mechanically rigid at all times
Ensuring uniform electric field distribution across the scaffold
Preventing the scaffold from melting
Avoiding the use of any polymers
Explanation - Uneven fields can lead to localized over‑stimulation or cell death, compromising tissue growth and scaffold integrity.
Correct answer is: Ensuring uniform electric field distribution across the scaffold
Q.11 Which imaging technique can assess scaffold porosity in situ without destroying the sample?
X-ray computed tomography (CT)
Ultrasound
MRI
Electron microscopy
Explanation - CT provides 3D volumetric data that reveal internal pore distribution while preserving the scaffold.
Correct answer is: X-ray computed tomography (CT)
Q.12 What is the role of a microfluidic channel within a scaffold?
To increase electrical resistance
To supply nutrients and oxygen while removing waste
To reinforce mechanical strength
To act as an electrical insulator
Explanation - Microfluidic channels mimic capillary networks, enhancing cell viability in thicker scaffolds.
Correct answer is: To supply nutrients and oxygen while removing waste
Q.13 Which of these properties is NOT typically optimized during scaffold design?
Mechanical stiffness
Surface charge
Color
Biodegradation rate
Explanation - Color is generally irrelevant to scaffold function unless used for imaging; other properties directly influence cellular responses.
Correct answer is: Color
Q.14 How can a scaffold be engineered to release growth factors over time?
By incorporating porous microcapsules that degrade at a controlled rate
By applying a magnetic field to the scaffold
By using a rigid, non‑degradable core
By coating the scaffold with a sugar layer
Explanation - Encapsulation of growth factors in degradable carriers allows gradual release synchronized with scaffold resorption.
Correct answer is: By incorporating porous microcapsules that degrade at a controlled rate
Q.15 What is a primary concern when using metallic implants in tissue engineering?
They are too flexible for load‑bearing applications
They corrode and may release toxic ions
They cannot be fabricated via 3D printing
They lack electrical conductivity
Explanation - Corrosion of metals like titanium or stainless steel can release ions that harm cells and trigger inflammation.
Correct answer is: They corrode and may release toxic ions
Q.16 Which parameter is crucial for ensuring that a conductive scaffold does not generate excessive heat during electrical stimulation?
Electrical resistance
Mechanical strength
Pore size
Surface roughness
Explanation - High resistance can cause Joule heating; low resistance ensures safe, uniform stimulation without damaging tissues.
Correct answer is: Electrical resistance
Q.17 Why is a gradient stiffness scaffold advantageous for bone‑to‑soft tissue interfaces?
It prevents any cell adhesion
It matches the mechanical properties of adjacent tissues, reducing stress shielding
It increases the scaffold’s electrical resistance
It accelerates scaffold degradation
Explanation - Gradients mimic natural transitions, allowing seamless integration and reducing load mismatch.
Correct answer is: It matches the mechanical properties of adjacent tissues, reducing stress shielding
Q.18 Which of the following is a typical method to increase the wettability of a polymer scaffold?
Plasma treatment
Increasing pore size beyond 1 mm
Coating with hydrophobic oils
Heating the scaffold to 200°C
Explanation - Plasma introduces polar functional groups, improving hydrophilicity and cell adhesion.
Correct answer is: Plasma treatment
Q.19 Which cell type is commonly used to evaluate osteogenic potential of bone scaffolds?
HeLa cells
Human mesenchymal stem cells (hMSCs)
Neonatal fibroblasts
E. coli bacteria
Explanation - hMSCs can differentiate into osteoblasts, making them a standard model for bone tissue engineering.
Correct answer is: Human mesenchymal stem cells (hMSCs)
Q.20 What is the primary advantage of using a hydrogel scaffold over a rigid polymer scaffold for soft tissue engineering?
Higher mechanical strength
Better electrical insulation
Superior ability to mimic soft tissue elasticity
Longer degradation time
Explanation - Hydrogels can be engineered to have low stiffness comparable to soft tissues, improving cell compatibility.
Correct answer is: Superior ability to mimic soft tissue elasticity
Q.21 In electrospun fibrous scaffolds, what does the term 'fiber diameter' influence?
Color of the scaffold
Rate of electrical conductivity only
Cell attachment and infiltration
Magnetic properties
Explanation - Smaller fibers increase surface area and mimic natural ECM, promoting cell adhesion.
Correct answer is: Cell attachment and infiltration
Q.22 Which technique can create aligned fibers that guide cell orientation?
Randomized spinning
Electrospinning with a rotating collector
Static molding
Laser engraving
Explanation - A rotating drum aligns fibers, influencing cell alignment, important in nerve and muscle scaffolds.
Correct answer is: Electrospinning with a rotating collector
Q.23 What is the main purpose of using a sacrificial material during scaffold fabrication?
To increase scaffold density
To create internal pores after removal
To enhance electrical conductivity
To stabilize the scaffold during printing
Explanation - Sacrificial layers dissolve or evaporate, leaving voids that improve mass transport.
Correct answer is: To create internal pores after removal
Q.24 Which of the following is a disadvantage of using silk fibroin as a scaffold material?
It is not biodegradable
It has poor mechanical strength compared to synthetic polymers
It cannot be sterilized
It has no natural bioactive motifs
Explanation - Silk fibroin degrades slowly and can be weak under load, limiting use in load‑bearing applications.
Correct answer is: It has poor mechanical strength compared to synthetic polymers
Q.25 How can the electrical impedance of a scaffold be measured?
Using a rheometer
Using a potentiostat in electrochemical impedance spectroscopy (EIS)
Using a UV-Vis spectrophotometer
Using a mass spectrometer
Explanation - EIS applies a small AC signal and measures the impedance spectrum of the scaffold.
Correct answer is: Using a potentiostat in electrochemical impedance spectroscopy (EIS)
Q.26 Which design principle helps to reduce the foreign body response to a scaffold?
High porosity
High surface roughness
Large pore size
Sharp edges
Explanation - Porous structures allow tissue infiltration and reduce macrophage activation compared to dense surfaces.
Correct answer is: High porosity
Q.27 Why is the Young's modulus of a scaffold important?
It determines scaffold color
It indicates how stiff the scaffold is, influencing cell mechanotransduction
It controls scaffold electrical resistance
It affects the scaffold's melting point
Explanation - Matching Young's modulus to native tissue reduces stress shielding and promotes proper cell signaling.
Correct answer is: It indicates how stiff the scaffold is, influencing cell mechanotransduction
Q.28 What is a typical method to functionalize a scaffold surface to promote cell adhesion?
Coating with polyethylene glycol (PEG)
Placing a magnetic field over it
Treating with oxygen plasma
Encapsulating with oil
Explanation - Plasma introduces reactive groups that can bind adhesion peptides or proteins.
Correct answer is: Treating with oxygen plasma
Q.29 Which of the following best describes a 'bioactive' scaffold?
One that degrades instantly
One that releases growth factors or presents bioactive cues
One that blocks cell adhesion
One that is made of glass
Explanation - Bioactive scaffolds actively influence cell behavior rather than being passive support.
Correct answer is: One that releases growth factors or presents bioactive cues
Q.30 Which of the following is NOT a common method for scaffold sterilization?
Ethylene oxide gas
Gamma radiation
Boiling at 100°C
UV‑C irradiation
Explanation - Many polymeric scaffolds cannot tolerate high temperatures; boiling may denature them.
Correct answer is: Boiling at 100°C
Q.31 In nerve tissue engineering, what feature of a scaffold promotes axonal guidance?
Random pore distribution
Aligned microchannels
High surface hydrophobicity
Large mechanical stiffness
Explanation - Aligned channels act as physical guides for extending axons, improving regeneration.
Correct answer is: Aligned microchannels
Q.32 What is the purpose of using a 3D‑printed lattice structure in bone scaffolds?
To reduce weight and increase surface area for cell attachment
To make the scaffold invisible under X‑ray
To prevent any degradation
To block nutrient diffusion
Explanation - Lattice designs provide mechanical support while allowing vascular infiltration.
Correct answer is: To reduce weight and increase surface area for cell attachment
Q.33 Which property of a scaffold is directly linked to its ability to support cell migration?
Electrical conductivity
Pore interconnectivity
Thermal expansion coefficient
Color intensity
Explanation - Interconnected pores provide pathways for cells to move and spread through the scaffold.
Correct answer is: Pore interconnectivity
Q.34 What is the main function of an electrochemical sensor incorporated into a tissue scaffold?
To measure environmental temperature
To monitor local pH or oxygen levels in real time
To deliver growth factors
To generate mechanical stimuli
Explanation - Sensors provide feedback on the microenvironment, enabling adaptive control of scaffold properties.
Correct answer is: To monitor local pH or oxygen levels in real time
Q.35 Which technique uses light to cure photosensitive polymers into solid structures?
Stereolithography (SLA)
Mold casting
Electrospinning
Laser sintering
Explanation - SLA relies on a laser or light source to polymerize resin layer by layer.
Correct answer is: Stereolithography (SLA)
Q.36 Which parameter is critical for ensuring a scaffold’s mechanical compatibility with cartilage?
High compressive modulus
Low compressive modulus
High tensile strength
High thermal conductivity
Explanation - Cartilage is soft; a scaffold too stiff can cause stress shielding and degeneration.
Correct answer is: Low compressive modulus
Q.37 Which of the following is a benefit of using a hybrid scaffold composed of both polymer and ceramic?
Improved electrical insulation
Enhanced mechanical strength and bioactivity
Reduced pore size
Increased color uniformity
Explanation - Ceramics like hydroxyapatite provide bone‑like properties while polymers offer flexibility.
Correct answer is: Enhanced mechanical strength and bioactivity
Q.38 Why is a low initial burst release of growth factors undesirable in scaffold design?
It consumes too much energy
It can cause cytotoxicity and waste of the factor
It improves scaffold strength
It increases scaffold weight
Explanation - A rapid release can overwhelm cells and deplete the reservoir prematurely.
Correct answer is: It can cause cytotoxicity and waste of the factor
Q.39 Which of the following is a typical indicator of scaffold cytotoxicity?
High cell proliferation
Low reactive oxygen species production
Release of inflammatory cytokines
Uniform cell distribution
Explanation - Inflammatory cytokines indicate an immune response to toxic scaffold components.
Correct answer is: Release of inflammatory cytokines
Q.40 Which electrical stimulation waveform is commonly used to promote bone formation?
Direct current (DC)
Pulsed electrical current
Alternating current (AC) at 50 Hz
Sinusoidal current at 1 kHz
Explanation - Pulsed currents mimic natural bioelectric signals and are effective for osteogenesis.
Correct answer is: Pulsed electrical current
Q.41 What is the purpose of using a gradient pore size in a scaffold?
To create a decorative pattern
To mimic the natural transition from dense to porous tissue
To increase scaffold density
To make the scaffold more opaque
Explanation - Gradients support different cell types and facilitate integration with surrounding tissues.
Correct answer is: To mimic the natural transition from dense to porous tissue
Q.42 Which material is often used for conductive scaffolds that also degrades in physiological conditions?
Polyaniline
PEDOT:PSS
Polypyrrole
Polyurethane
Explanation - Polypyrrole can be synthesized to be biocompatible and gradually degrade in bodily fluids.
Correct answer is: Polypyrrole
Q.43 Which of the following is a typical challenge when scaling up scaffold production for clinical use?
Ensuring uniform cell seeding
Increasing scaffold color uniformity
Reducing the number of pores
Eliminating all electrical properties
Explanation - Large‑scale production must maintain consistent cell distribution and viability throughout the scaffold.
Correct answer is: Ensuring uniform cell seeding
Q.44 What is the main role of crosslinking in hydrogel scaffolds?
To increase scaffold temperature
To control mechanical stiffness and degradation
To reduce scaffold color
To make the scaffold transparent
Explanation - Crosslinking density determines how strong and how quickly a hydrogel breaks down.
Correct answer is: To control mechanical stiffness and degradation
Q.45 Which property of a scaffold is most important for supporting electrical signal propagation in neural tissue engineering?
Hydrophobicity
Electrical conductivity
Pore size
Mechanical stiffness
Explanation - Conductive scaffolds allow electrical impulses to travel along the tissue, aiding neuron function.
Correct answer is: Electrical conductivity
Q.46 Why is it important to match the degradation rate of a scaffold to tissue regeneration?
To maintain scaffold presence indefinitely
To provide mechanical support until new tissue forms
To ensure scaffold does not dissolve in the first hour
To avoid any electrical signals
Explanation - A scaffold that degrades too quickly fails to support tissue; too slow a scaffold hinders integration.
Correct answer is: To provide mechanical support until new tissue forms
Q.47 Which fabrication technique can produce hollow microtubes that serve as channels for nutrient flow?
Electrospinning
3D bioprinting using coaxial nozzles
Mold casting
Laser etching
Explanation - Coaxial printing allows simultaneous deposition of core and sheath materials to create hollow structures.
Correct answer is: 3D bioprinting using coaxial nozzles
Q.48 Which of the following is a key parameter to assess in the mechanical testing of a scaffold?
Electrical resistance
Compressive strength
Optical clarity
Color saturation
Explanation - Compressive strength determines how well a scaffold can resist loads similar to those in the body.
Correct answer is: Compressive strength
Q.49 What is the primary reason for incorporating micro‑electrodes into a tissue scaffold?
To increase scaffold stiffness
To provide electrical stimulation and monitor cell activity
To block nutrient diffusion
To improve scaffold transparency
Explanation - Micro‑electrodes deliver controlled stimuli and record electrical signals from cells.
Correct answer is: To provide electrical stimulation and monitor cell activity
Q.50 Which of the following is NOT a typical advantage of 3D printing over traditional scaffold fabrication?
Ability to create patient‑specific geometries
Higher production speed
Precise control over internal architecture
Ability to incorporate multiple materials simultaneously
Explanation - 3D printing is generally slower; its strengths are customization and design flexibility.
Correct answer is: Higher production speed
Q.51 Which type of scaffold is best suited for delivering drugs locally to a wound site?
Rigid ceramic scaffold
Hydrogel scaffold
Metallic implant
Polyurethane film
Explanation - Hydrogels can encapsulate and release therapeutic agents while maintaining a moist environment.
Correct answer is: Hydrogel scaffold
Q.52 What effect does increasing scaffold porosity typically have on mechanical stiffness?
It increases stiffness
It decreases stiffness
It has no effect
It makes the scaffold opaque
Explanation - More pores mean less material to bear load, reducing overall stiffness.
Correct answer is: It decreases stiffness
Q.53 Which of the following is a characteristic of a biodegradable polymer?
It never degrades in the body
It decomposes into non‑toxic products
It is magnetic
It is always electrically conductive
Explanation - Biodegradability ensures the scaffold eventually disappears without harmful residues.
Correct answer is: It decomposes into non‑toxic products
Q.54 What is the main challenge associated with electrically conductive hydrogels?
They cannot be 3D printed
They lose conductivity when dehydrated
They are too rigid for soft tissues
They are opaque
Explanation - Hydrogels rely on water for ion transport; drying reduces ionic pathways.
Correct answer is: They lose conductivity when dehydrated
Q.55 Which parameter is critical when evaluating the biocompatibility of a scaffold?
Color
Electrical impedance
Cytotoxicity assays
Thermal expansion coefficient
Explanation - Cytotoxicity tests measure how the scaffold affects cell viability and proliferation.
Correct answer is: Cytotoxicity assays
Q.56 Which of the following methods can enhance the integration of a scaffold with host tissue?
Increasing scaffold opacity
Embedding growth factors
Removing all pores
Using a high‑temperature metal core
Explanation - Growth factors stimulate cell migration and differentiation, improving tissue integration.
Correct answer is: Embedding growth factors
Q.57 Why is it important to sterilize scaffolds before implantation?
To improve their electrical conductivity
To remove potential contaminants that could cause infection
To make them more transparent
To increase their weight
Explanation - Sterilization eliminates bacteria, viruses, and spores that would otherwise lead to infection.
Correct answer is: To remove potential contaminants that could cause infection
Q.58 Which property of a scaffold determines how well it can be deformed under stress and then return to its original shape?
Elastic modulus
Compressive strength
Electrical resistance
Pore interconnectivity
Explanation - Elastic modulus reflects the scaffold’s ability to elastically deform and recover under load.
Correct answer is: Elastic modulus
Q.59 Which type of scaffold is typically used for cartilage regeneration?
Rigid polymeric scaffold
Soft hydrogel scaffold
Metallic scaffold
Ceramic scaffold
Explanation - Cartilage requires a soft, hydrated environment that hydrogels provide.
Correct answer is: Soft hydrogel scaffold
Q.60 In the context of electrical stimulation, what does 'frequency' refer to?
The voltage applied
The number of pulses per second
The resistance of the scaffold
The size of the pores
Explanation - Frequency indicates how often electrical pulses occur, affecting cell response.
Correct answer is: The number of pulses per second
Q.61 Which of the following is a commonly used bio‑ink for 3D bioprinting?
Silicone oil
Alginate‑gelatin mixture
Polystyrene
Teflon
Explanation - Alginate and gelatin form a printable, cell‑friendly hydrogel suitable for bioprinting.
Correct answer is: Alginate‑gelatin mixture
Q.62 Which factor is critical for ensuring that a conductive scaffold does not cause thermal damage during electrical stimulation?
Low electrical resistance
High porosity
Large pore size
High stiffness
Explanation - Low resistance minimizes heat generation during current flow.
Correct answer is: Low electrical resistance
Q.63 Which of the following is an example of a bioactive ceramic used in bone scaffolds?
Hydroxyapatite
Polyethylene
Polystyrene
Silicone rubber
Explanation - Hydroxyapatite closely resembles bone mineral, promoting osteoconduction.
Correct answer is: Hydroxyapatite
Q.64 What is the main advantage of using a 'smart' scaffold that can sense and respond to environmental changes?
It looks futuristic
It can adjust drug release rates automatically
It reduces the need for sterilization
It increases scaffold stiffness permanently
Explanation - Smart scaffolds respond to stimuli (pH, temperature) to modulate therapeutic release.
Correct answer is: It can adjust drug release rates automatically
Q.65 Which technique can be used to measure the degradation rate of a scaffold in vitro?
Thermogravimetric analysis (TGA)
Electrical impedance spectroscopy (EIS)
UV‑Vis spectroscopy
Rheology
Explanation - TGA tracks weight loss over time to quantify material degradation.
Correct answer is: Thermogravimetric analysis (TGA)
Q.66 Which material property is most influenced by the presence of charged groups on a polymer backbone?
Electrical conductivity
Mechanical strength
Hydrophobicity
Color
Explanation - Charged groups enable ion transport, increasing the material’s conductivity.
Correct answer is: Electrical conductivity
Q.67 What is a key consideration when using silk fibroin for scaffold fabrication?
It cannot be sterilized
It requires high temperatures to set
It degrades slowly but can be processed into various architectures
It has no natural bioactive motifs
Explanation - Silk fibroin offers tunable degradation and can be shaped via electrospinning or 3D printing.
Correct answer is: It degrades slowly but can be processed into various architectures
Q.68 Which of the following best describes a 'biomimetic' scaffold?
It looks like a natural tissue under a microscope
It replicates the structural and functional features of native extracellular matrix
It is made of glass
It cannot be used in vivo
Explanation - Biomimetic scaffolds mimic the environment cells naturally experience, promoting integration.
Correct answer is: It replicates the structural and functional features of native extracellular matrix
Q.69 Which property of a scaffold is measured by a mechanical test that applies a compressive load until failure?
Compressive strength
Tensile strength
Electrical resistance
Porosity
Explanation - Compressive tests determine how much load a scaffold can bear before breaking.
Correct answer is: Compressive strength
Q.70 Which of the following is a common method to increase scaffold porosity without compromising mechanical integrity?
Increasing polymer chain length
Adding a sacrificial filler that later dissolves
Decreasing the scaffold thickness
Coating with metal
Explanation - Sacrificial fillers create pores after removal, leaving the primary scaffold intact.
Correct answer is: Adding a sacrificial filler that later dissolves
Q.71 What is the function of a 'bio‑ink' in 3D bioprinting?
To provide structural support only
To deliver cells and biomolecules within a printable matrix
To act as a solvent for metal printing
To increase scaffold temperature
Explanation - Bio‑inks are formulations that encapsulate living cells, enabling their deposition during printing.
Correct answer is: To deliver cells and biomolecules within a printable matrix
Q.72 Which of the following is NOT a typical use for microfabricated electrodes in tissue scaffolds?
Delivering electrical stimulation
Recording cellular electrical activity
Acting as mechanical anchors
Measuring local pH changes
Explanation - Microfabricated electrodes primarily provide electrical interfaces, not mechanical support.
Correct answer is: Acting as mechanical anchors
Q.73 Which phenomenon occurs when a scaffold releases growth factors at a rapid, uncontrolled rate?
Burst release
Sustained release
Delayed release
Zero release
Explanation - Burst release refers to a sudden high concentration of factor shortly after implantation.
Correct answer is: Burst release
Q.74 Which of the following materials is known for being both electrically conductive and biodegradable?
Polypyrrole
Polystyrene
Teflon
Glass
Explanation - Polypyrrole can be tailored to degrade while maintaining conductivity.
Correct answer is: Polypyrrole
Q.75 What is the main advantage of using a 'gradient stiffness' design in bone scaffolds?
It makes the scaffold more visually appealing
It allows the scaffold to match the stiffness of the surrounding tissues at different depths
It reduces the scaffold's pore size
It eliminates the need for sterilization
Explanation - Gradient stiffness reduces mechanical mismatch and promotes seamless integration.
Correct answer is: It allows the scaffold to match the stiffness of the surrounding tissues at different depths
Q.76 Which property is most affected by increasing the crosslinking density of a hydrogel scaffold?
Electrical resistance
Swelling ratio and mechanical stiffness
Color intensity
Magnetic permeability
Explanation - More crosslinks reduce swelling and increase stiffness, altering cell interactions.
Correct answer is: Swelling ratio and mechanical stiffness
Q.77 Which of the following is a key challenge for in vivo implantation of conductive scaffolds?
Maintaining constant electrical conductivity over time
Making the scaffold invisible under X‑ray
Ensuring scaffold has no pores
Using only non‑degradable materials
Explanation - Degradation can change conductivity; maintaining a stable electrical environment is critical.
Correct answer is: Maintaining constant electrical conductivity over time
Q.78 What is the purpose of adding a 'bioactive' coating to a scaffold surface?
To increase the scaffold’s thermal conductivity
To provide signaling cues that enhance cell adhesion and differentiation
To make the scaffold opaque
To reduce its weight
Explanation - Bioactive coatings like RGD peptides or growth factors improve cellular responses.
Correct answer is: To provide signaling cues that enhance cell adhesion and differentiation
Q.79 Which of the following best describes 'electrospinning'?
A process that melts polymers to form fibers
A process that uses high voltage to pull fine polymer jets forming micro‑ to nano‑fibers
A chemical reaction to produce nanoparticles
A technique for measuring scaffold resistance
Explanation - Electrospinning creates fibrous mats that resemble the extracellular matrix.
Correct answer is: A process that uses high voltage to pull fine polymer jets forming micro‑ to nano‑fibers
Q.80 In a hydrogel scaffold, what is the role of 'pore interconnectivity'?
To prevent any cell migration
To allow nutrients, gases, and waste to travel through the scaffold
To make the hydrogel rigid
To reduce electrical conductivity
Explanation - Interconnected pores ensure proper mass transport essential for cell survival.
Correct answer is: To allow nutrients, gases, and waste to travel through the scaffold
Q.81 Which parameter determines how long a scaffold will retain its shape after deformation?
Elastic modulus
Compressive strength
Electrical resistance
Pore size
Explanation - Elastic modulus quantifies the scaffold’s ability to return to its original shape.
Correct answer is: Elastic modulus
Q.82 What is the main benefit of using a 'dual‑phase' scaffold with both polymer and ceramic components?
It provides both mechanical strength and electrical conductivity
It increases scaffold opacity
It eliminates the need for cells
It prevents any degradation
Explanation - The polymer phase offers flexibility while the ceramic phase adds stiffness and sometimes bioactivity.
Correct answer is: It provides both mechanical strength and electrical conductivity
Q.83 Which technique can be used to incorporate cells into a scaffold before it fully degrades?
Co‑printing of cell‑laden bio‑ink
Embedding cells in a sacrificial sugar mold
Storing the scaffold in a freezer
Painting cells on the surface after implantation
Explanation - Bioprinting allows precise deposition of cells within the scaffold matrix.
Correct answer is: Co‑printing of cell‑laden bio‑ink
Q.84 Why is 'pH stability' important for scaffold materials?
To keep the scaffold color unchanged
To maintain consistent electrical resistance
To prevent drastic changes in cell viability and scaffold degradation
To increase scaffold stiffness
Explanation - Scaffold materials and cells are sensitive to pH; significant shifts can cause cell death.
Correct answer is: To prevent drastic changes in cell viability and scaffold degradation
Q.85 Which of the following is a characteristic of a 'micro‑electromechanical system' (MEMS) used in tissue scaffolds?
It has a very large size
It integrates sensors and actuators at microscale
It is only used for mechanical testing
It cannot interface with biological tissues
Explanation - MEMS allow precise control of stimuli and monitoring at the cellular level.
Correct answer is: It integrates sensors and actuators at microscale
Q.86 Which property of a scaffold influences its ability to support neuronal growth?
Electrical conductivity
Color
Mechanical stiffness only
Thermal conductivity
Explanation - Neurons respond to electrical cues; conductive scaffolds can enhance axonal extension.
Correct answer is: Electrical conductivity
Q.87 Which of the following is a potential consequence of scaffold degradation in vivo?
Release of acidic or basic byproducts that can harm cells
Permanent mechanical support
Elimination of all pores
Increased scaffold conductivity
Explanation - Degradation products can alter local pH and damage surrounding tissues.
Correct answer is: Release of acidic or basic byproducts that can harm cells
Q.88 What is the main advantage of using a 'hydrogel' scaffold in wound healing?
It maintains a moist environment and can deliver growth factors
It provides rigid support to bone
It is highly electrically conductive
It is completely non‑biodegradable
Explanation - Hydrogels keep wounds moist, which promotes faster healing.
Correct answer is: It maintains a moist environment and can deliver growth factors
Q.89 Which technique is used to create a scaffold with precise micro‑scale features?
Melt extrusion
Laser ablation
Mold casting
Syringe injection
Explanation - Laser ablation can etch fine patterns onto a surface with high precision.
Correct answer is: Laser ablation
Q.90 Which of the following best describes a 'bio‑resorbable' scaffold?
It remains permanently in the body
It dissolves in the body over time, leaving only natural tissue
It is made of metal
It can conduct electricity indefinitely
Explanation - Bioreresorbable scaffolds degrade as new tissue forms, eliminating foreign bodies.
Correct answer is: It dissolves in the body over time, leaving only natural tissue
Q.91 In a conductive scaffold, which of the following parameters most directly influences the amount of current that can pass through?
Electrical resistance
Pore size
Color intensity
Mechanical stiffness
Explanation - Lower resistance allows more current for the same voltage.
Correct answer is: Electrical resistance
Q.92 Which of the following is a primary benefit of using a 'smart' hydrogel that can change stiffness in response to stimuli?
It can respond to changes in temperature or pH, providing dynamic mechanical cues to cells
It eliminates the need for electrical stimulation
It reduces scaffold weight drastically
It increases scaffold opacity
Explanation - Dynamic stiffness mimics the natural mechanical environment of many tissues.
Correct answer is: It can respond to changes in temperature or pH, providing dynamic mechanical cues to cells
Q.93 Which of the following materials is a natural polysaccharide commonly used for scaffold fabrication?
Cellulose
Polystyrene
Polylactic acid
Polyethylene terephthalate
Explanation - Cellulose and derivatives are biocompatible and can be processed into various scaffold forms.
Correct answer is: Cellulose
Q.94 What is the main goal of using 'micro‑channels' in a scaffold for tissue engineering?
To increase scaffold weight
To guide cell alignment and provide pathways for nutrient transport
To reduce scaffold electrical conductivity
To block vascularization
Explanation - Micro‑channels mimic natural vascular networks and help cells orient along defined paths.
Correct answer is: To guide cell alignment and provide pathways for nutrient transport
Q.95 Which property of a scaffold is critical for ensuring that electrical stimuli do not cause local heating during stimulation?
Electrical resistance
Pore interconnectivity
Surface roughness
Color intensity
Explanation - High resistance can lead to Joule heating, which may damage tissues.
Correct answer is: Electrical resistance
Q.96 Which of the following is an advantage of using a 'multiscale' scaffold design?
It eliminates the need for cell seeding
It provides both macro‑ and micro‑level structures that mimic tissue architecture
It simplifies scaffold manufacturing
It ensures zero electrical conductivity
Explanation - Multiscale designs replicate the complex hierarchical structure of native tissues.
Correct answer is: It provides both macro‑ and micro‑level structures that mimic tissue architecture