Q.1 Which of the following polymers is most commonly used as a biodegradable carrier for drug delivery due to its FDA‑approved status?
Polyvinyl chloride (PVC)
Polylactic acid (PLA)
Polyethylene terephthalate (PET)
Polytetrafluoroethylene (PTFE)
Explanation - PLA is an FDA‑approved biodegradable polymer widely employed for controlled drug release because it degrades into lactic acid, a naturally occurring metabolite.
Correct answer is: Polylactic acid (PLA)
Q.2 The term “biocompatibility” primarily refers to:
The ability of a material to conduct electricity
The capacity of a material to degrade in water
The lack of toxic or immunogenic response when in contact with biological tissues
The mechanical strength of a polymer
Explanation - Biocompatibility assesses how a material interacts with living tissue without causing adverse reactions.
Correct answer is: The lack of toxic or immunogenic response when in contact with biological tissues
Q.3 Which degradation mechanism dominates the breakdown of poly(lactic‑co‑glycolic acid) (PLGA) in the body?
Oxidative degradation
Enzymatic hydrolysis
Photolysis
Thermal decomposition
Explanation - PLGA degrades primarily by hydrolysis of its ester bonds, a process accelerated by enzymes present in physiological fluids.
Correct answer is: Enzymatic hydrolysis
Q.4 A drug‑loaded nanoparticle made from chitosan is expected to have which of the following advantages?
High electrical conductivity
Intrinsic antimicrobial activity and mucoadhesion
Magnetic responsiveness
Resistance to enzymatic degradation
Explanation - Chitosan is a natural polysaccharide that exhibits antimicrobial properties and can adhere to mucosal surfaces, enhancing drug residence time.
Correct answer is: Intrinsic antimicrobial activity and mucoadhesion
Q.5 In drug delivery, the term “burst release” refers to:
A sudden increase in drug concentration shortly after administration
The complete elimination of the drug within minutes
The steady, linear release of drug over weeks
A release pattern that is unaffected by carrier composition
Explanation - Burst release describes an initial rapid release of a large fraction of the drug, often due to surface‑adsorbed drug molecules.
Correct answer is: A sudden increase in drug concentration shortly after administration
Q.6 Which property is most critical to evaluate when assessing the biocompatibility of a new polymeric carrier?
Dielectric constant
Water contact angle
Cytotoxicity toward relevant cell lines
Electrical resistivity
Explanation - Cytotoxicity assays reveal whether the polymer or its degradation products harm cells, a key factor in biocompatibility.
Correct answer is: Cytotoxicity toward relevant cell lines
Q.7 Which of the following statements about polycaprolactone (PCL) is true?
It degrades within 24 hours after implantation.
It is highly crystalline and degrades very slowly, often over months to years.
It is electrically conductive.
It cannot be processed into nanofibers.
Explanation - PCL’s high crystallinity slows hydrolytic degradation, making it suitable for long‑term release applications.
Correct answer is: It is highly crystalline and degrades very slowly, often over months to years.
Q.8 The primary advantage of using biodegradable carriers over non‑degradable ones is:
Reduced need for surgical removal after therapy
Higher electrical conductivity
Lower cost of manufacturing
Increased mechanical strength
Explanation - Biodegradable carriers naturally break down, eliminating the need for a second procedure to extract the device.
Correct answer is: Reduced need for surgical removal after therapy
Q.9 Which analytical technique is most suitable for measuring the molecular weight distribution of a polymer used in drug delivery?
Fourier‑transform infrared spectroscopy (FTIR)
Gel permeation chromatography (GPC)
Scanning electron microscopy (SEM)
X‑ray diffraction (XRD)
Explanation - GPC separates polymer chains based on size, providing molecular weight distribution data critical for predicting degradation rates.
Correct answer is: Gel permeation chromatography (GPC)
Q.10 A biodegradable carrier releases a drug via diffusion rather than degradation. Which material property primarily controls this diffusion rate?
Polymer’s glass transition temperature (Tg)
Polymer’s crystallinity and porosity
Polymer’s electrical resistivity
Polymer’s optical transparency
Explanation - Diffusion is governed by the free volume within the polymer matrix; higher porosity and lower crystallinity increase diffusion rates.
Correct answer is: Polymer’s crystallinity and porosity
Q.11 Which of the following is a common method to improve the biocompatibility of a synthetic polymer?
Coating it with a thin layer of gold
Blending it with a natural polymer such as gelatin
Increasing its electrical conductivity
Adding heavy metal salts
Explanation - Natural polymers often contain cell‑recognition motifs that reduce foreign‑body responses and improve compatibility.
Correct answer is: Blending it with a natural polymer such as gelatin
Q.12 In the context of drug delivery, the term “stealth” typically refers to:
Materials that are invisible to the naked eye
Nanoparticles coated with polyethylene glycol (PEG) to avoid immune detection
Carriers that conduct electricity without resistance
Polymers that dissolve instantly in blood
Explanation - PEGylation creates a hydrophilic shell that reduces protein adsorption and prolongs circulation time.
Correct answer is: Nanoparticles coated with polyethylene glycol (PEG) to avoid immune detection
Q.13 Which factor most strongly influences the rate at which PLGA degrades in vivo?
The ratio of lactic acid to glycolic acid monomers
The color of the polymer
The polymer’s magnetic susceptibility
The presence of a fluorescent tag
Explanation - Higher glycolic acid content accelerates hydrolysis due to its greater hydrophilicity, thus increasing degradation rate.
Correct answer is: The ratio of lactic acid to glycolic acid monomers
Q.14 A biodegradable carrier must meet ISO 10993 standards. What does this standard assess?
Electrical conductivity of medical devices
Biological evaluation of medical devices for safety and biocompatibility
Mechanical fatigue of orthopedic implants
Magnetic resonance imaging compatibility
Explanation - ISO 10993 provides a framework for testing cytotoxicity, sensitization, irritation, and systemic toxicity of medical materials.
Correct answer is: Biological evaluation of medical devices for safety and biocompatibility
Q.15 Which biodegradable polymer is derived from a natural source and is often used for bone tissue engineering?
Polyvinyl alcohol (PVA)
Silicon nitride
Hydroxyapatite
Collagen
Explanation - Collagen is the main structural protein in connective tissue and degrades naturally, making it suitable for bone regeneration scaffolds.
Correct answer is: Collagen
Q.16 What is the main reason that a high surface‑to‑volume ratio is advantageous for biodegradable nanoparticles in drug delivery?
It increases electrical conductivity.
It enhances drug loading capacity.
It accelerates degradation and drug release kinetics.
It makes the particles magnetic.
Explanation - A larger surface area relative to volume exposes more polymer chains to bodily fluids, promoting faster hydrolysis and drug diffusion.
Correct answer is: It accelerates degradation and drug release kinetics.
Q.17 Which of the following is a common in‑vitro assay to assess the hemocompatibility of a biodegradable carrier?
MTT assay
Hemolysis test
Four‑point bending test
Thermal gravimetric analysis (TGA)
Explanation - The hemolysis test measures red blood cell rupture caused by the material, indicating compatibility with blood.
Correct answer is: Hemolysis test
Q.18 A drug‑carrier system designed to release its payload over 6 months would most likely use which polymer composition?
High glycolic acid content PLGA (50:50)
Low glycolic acid content PLGA (85:15)
Pure polylactic acid (PLA)
Polyethylene glycol (PEG)
Explanation - Lower glycolic acid slows hydrolysis, extending degradation and drug release up to several months.
Correct answer is: Low glycolic acid content PLGA (85:15)
Q.19 When a biodegradable polymer undergoes hydrolytic degradation, the primary by‑products are:
Carbon dioxide and water
Organic acids (e.g., lactic acid, glycolic acid)
Heavy metal ions
Nitrogen gas
Explanation - Ester bond cleavage generates monomers such as lactic and glycolic acid, which are metabolized by the body.
Correct answer is: Organic acids (e.g., lactic acid, glycolic acid)
Q.20 Which method is commonly employed to fabricate biodegradable nanofibers for drug delivery?
Melt extrusion
Electrospinning
Laser ablation
Sputtering
Explanation - Electrospinning uses a high‑voltage electric field to draw polymer solutions into ultra‑thin fibers, ideal for high surface area drug carriers.
Correct answer is: Electrospinning
Q.21 A polymer with a high glass transition temperature (Tg) will generally:
Degrade faster in the body
Be more flexible at body temperature
Remain glassy (rigid) at physiological temperature
Conduct electricity better
Explanation - If Tg > 37 °C, the polymer stays in a glassy state at body temperature, affecting its mechanical properties and degradation profile.
Correct answer is: Remain glassy (rigid) at physiological temperature
Q.22 Which of the following is NOT a typical criterion for selecting a biodegradable carrier for ocular drug delivery?
Transparency
Biodegradability within weeks
High mechanical stiffness
Non‑irritating to corneal tissue
Explanation - Excessive stiffness can cause discomfort and damage delicate ocular tissues; flexibility is preferred.
Correct answer is: High mechanical stiffness
Q.23 The term “bio‑erosion” in drug delivery most closely describes:
Mechanical wear of a device
Chemical breakdown of a carrier by bodily fluids
Electrical discharge of a battery
Magnetic field induced degradation
Explanation - Bio‑erosion refers to the gradual dissolution or hydrolysis of a material when exposed to physiological environments.
Correct answer is: Chemical breakdown of a carrier by bodily fluids
Q.24 Which of the following biodegradable polymers is known for its pH‑sensitive degradation behavior, useful for targeting acidic tumor microenvironments?
Polyethylene glycol (PEG)
Poly(β‑amino ester) (PBAE)
Polytetrafluoroethylene (PTFE)
Polyvinyl chloride (PVC)
Explanation - PBAEs hydrolyze faster under acidic conditions, enabling preferential drug release in tumor sites.
Correct answer is: Poly(β‑amino ester) (PBAE)
Q.25 When assessing the long‑term biocompatibility of a biodegradable scaffold, which in‑vivo test is most informative?
Acute toxicity test in zebrafish embryos
Subcutaneous implantation in rodents for several months
Electrical impedance spectroscopy on the scaffold
UV‑Vis spectroscopy of scaffold extracts
Explanation - Long‑term implantation reveals chronic inflammatory responses, fibrous encapsulation, and degradation behavior in a living organism.
Correct answer is: Subcutaneous implantation in rodents for several months
Q.26 Which characteristic of a biodegradable carrier most directly influences its ability to avoid rapid clearance by the reticuloendothelial system (RES)?
Particle size below 5 nm
Neutral surface charge and PEGylation
High electrical conductivity
Magnetic susceptibility
Explanation - Neutral, hydrophilic surfaces reduce protein opsonization and subsequent uptake by RES macrophages.
Correct answer is: Neutral surface charge and PEGylation
Q.27 A biodegradable carrier that releases drug primarily through polymer erosion rather than diffusion is said to exhibit:
Zero‑order release kinetics
First‑order release kinetics
Burst release
Sustained release with lag phase
Explanation - Erosion‑controlled release can maintain a constant drug release rate, approximating zero‑order kinetics.
Correct answer is: Zero‑order release kinetics
Q.28 Which of the following is a major drawback of using highly crystalline biodegradable polymers for drug delivery?
Excessive electrical conductivity
Very rapid degradation
Low drug loading due to limited amorphous regions
Inability to be sterilized
Explanation - Crystalline regions restrict drug diffusion and encapsulation, reducing loading efficiency.
Correct answer is: Low drug loading due to limited amorphous regions
Q.29 The presence of which functional group in a polymer chain most directly facilitates hydrolytic degradation?
Ester (–COO–) groups
Amide (–CONH–) groups
Aromatic rings
Siloxane (–Si–O–) groups
Explanation - Ester bonds are susceptible to water‑mediated hydrolysis, a primary pathway for biodegradable polymer breakdown.
Correct answer is: Ester (–COO–) groups
Q.30 Which in‑vitro test would best predict the potential for an implanted biodegradable polymer to cause chronic inflammation?
Live/dead assay on fibroblasts
ELISA for pro‑inflammatory cytokines (e.g., TNF‑α, IL‑6)
Conductivity measurement of polymer extracts
Thermal degradation analysis
Explanation - Elevated cytokine levels indicate activation of immune pathways that could lead to chronic inflammation.
Correct answer is: ELISA for pro‑inflammatory cytokines (e.g., TNF‑α, IL‑6)
Q.31 Which of the following is an example of a stimulus‑responsive biodegradable carrier?
Thermo‑sensitive PLGA‑PEG‑PLGA hydrogel that gels at body temperature
Copper wire coil
Rigid stainless‑steel screw
Silicone oil droplet
Explanation - These hydrogels transition from sol to gel at physiological temperature, enabling in‑situ formation and drug release.
Correct answer is: Thermo‑sensitive PLGA‑PEG‑PLGA hydrogel that gels at body temperature
Q.32 For a biodegradable carrier intended for intravenous injection, which particle size range is generally considered optimal to avoid capillary blockage?
1–5 µm
200–500 nm
5–10 µm
10–50 nm
Explanation - Particles in the 200–500 nm range balance prolonged circulation with minimal risk of embolism.
Correct answer is: 200–500 nm
Q.33 A biodegradable polymer that is metabolized into CO₂ and H₂O in the body is:
Polylactic acid (PLA)
Polyethylene terephthalate (PET)
Polylactide‑co‑glycolide (PLGA)
Polyvinylidene fluoride (PVDF)
Explanation - PLGA hydrolyzes to lactic and glycolic acids, which enter the Krebs cycle and are ultimately converted to CO₂ and H₂O.
Correct answer is: Polylactide‑co‑glycolide (PLGA)
Q.34 Which of the following is a key factor that can cause an otherwise biocompatible polymer to become cytotoxic after degradation?
Accumulation of acidic degradation products lowering local pH
Increase in polymer molecular weight
Formation of metallic nanoparticles
Development of magnetic domains
Explanation - Acidic by‑products can cause local inflammation and cell death, compromising biocompatibility.
Correct answer is: Accumulation of acidic degradation products lowering local pH
Q.35 Which technique can be used to functionalize the surface of biodegradable nanoparticles with targeting ligands?
Physical vapor deposition
Carbodiimide‑mediated coupling (EDC/NHS chemistry)
X‑ray crystallography
Thermal annealing
Explanation - EDC/NHS activates carboxyl groups on the polymer surface, allowing covalent attachment of amine‑containing ligands.
Correct answer is: Carbodiimide‑mediated coupling (EDC/NHS chemistry)
Q.36 Which of the following statements best describes the term “bio‑resorbable”?
A material that can be re‑used after sterilization
A material that degrades and is eliminated from the body without surgical removal
A material that conducts electricity in biological tissues
A material that is opaque to X‑rays
Explanation - Bio‑resorbable devices are designed to be safely absorbed or excreted after fulfilling their therapeutic purpose.
Correct answer is: A material that degrades and is eliminated from the body without surgical removal
Q.37 When a biodegradable polymer carrier is designed for oral administration, which property is most critical for protecting the drug from the acidic stomach environment?
High electrical conductivity
Acid‑resistant coating or pH‑responsive polymer matrix
Magnetic susceptibility
Transparency
Explanation - A protective coating prevents premature drug degradation in low pH, allowing release in the intestine.
Correct answer is: Acid‑resistant coating or pH‑responsive polymer matrix
Q.38 Which analytical method would you use to monitor the release profile of a drug from a biodegradable polymer in vitro?
High‑performance liquid chromatography (HPLC)
Fourier‑transform infrared spectroscopy (FTIR)
Scanning electron microscopy (SEM)
Differential scanning calorimetry (DSC)
Explanation - HPLC quantifies drug concentration in release media over time, providing kinetic data.
Correct answer is: High‑performance liquid chromatography (HPLC)
Q.39 A biodegradable polymer that exhibits a shape‑memory effect at body temperature is most suitable for:
Electrical wiring
Self‑expanding stents
Magnetic resonance imaging contrast agents
Solar cells
Explanation - Shape‑memory polymers can be compacted for insertion and then expand to support a vessel once at body temperature.
Correct answer is: Self‑expanding stents
Q.40 Which of the following statements about the relationship between polymer molecular weight and degradation rate is generally true?
Higher molecular weight polymers degrade faster.
Lower molecular weight polymers degrade faster.
Molecular weight does not affect degradation.
Only crystalline polymers degrade.
Explanation - Shorter chains have more chain ends susceptible to hydrolysis, accelerating degradation.
Correct answer is: Lower molecular weight polymers degrade faster.
Q.41 In a biodegradable polymer matrix, the presence of which additive can accelerate degradation by catalyzing hydrolysis?
Calcium carbonate (basic filler)
Silica nanoparticles
Hydrophilic plasticizer (e.g., polyethylene glycol)
Gold nanorods
Explanation - PEG attracts water into the polymer, increasing hydrolysis rates.
Correct answer is: Hydrophilic plasticizer (e.g., polyethylene glycol)
Q.42 Which property of a biodegradable carrier most directly influences its ability to cross the blood‑brain barrier (BBB)?
Particle size below 100 nm and surface modification with BBB‑targeting ligands
High density
Magnetic susceptibility
Red fluorescence
Explanation - Small, ligand‑decorated nanoparticles can be transported via receptor‑mediated transcytosis across the BBB.
Correct answer is: Particle size below 100 nm and surface modification with BBB‑targeting ligands
Q.43 Which of the following is a key advantage of using dendrimer‑based biodegradable carriers?
Unlimited drug loading capacity
Highly branched architecture enabling precise drug encapsulation and surface functionalization
Inherent magnetic properties
Intrinsic fluorescence without modification
Explanation - Dendrimers provide well‑defined nanospaces for drug molecules and multiple sites for attaching targeting groups.
Correct answer is: Highly branched architecture enabling precise drug encapsulation and surface functionalization
Q.44 Which of the following tests would best assess the potential of a biodegradable polymer to cause allergic reactions in humans?
In‑vitro hemolysis assay
In‑vivo skin sensitization test (e.g., Guinea pig maximization test)
Electrical conductivity measurement
Thermal stability test
Explanation - Skin sensitization assays evaluate delayed‑type hypersensitivity, a common form of allergy.
Correct answer is: In‑vivo skin sensitization test (e.g., Guinea pig maximization test)
Q.45 A polymer that degrades via enzymatic cleavage by matrix metalloproteinases (MMPs) would be particularly useful for:
Targeting healthy liver tissue
Delivering drugs to tumor microenvironments where MMPs are overexpressed
Long‑term cardiac pacing leads
Bone cement applications
Explanation - MMP‑responsive polymers degrade preferentially where the enzyme is abundant, enhancing tumor‑specific release.
Correct answer is: Delivering drugs to tumor microenvironments where MMPs are overexpressed
Q.46 What is the main purpose of sterilizing biodegradable drug carriers before clinical use?
To increase polymer molecular weight
To eliminate microbial contamination without altering degradation behavior
To improve electrical conductivity
To change the color of the carrier
Explanation - Sterilization must preserve the carrier’s physicochemical properties while ensuring safety.
Correct answer is: To eliminate microbial contamination without altering degradation behavior
Q.47 Which biodegradable polymer is derived from a renewable resource and is often used for creating microneedles?
Polystyrene
Poly(lactic‑co‑glycolic acid) (PLGA)
Polylactic acid (PLA)
Polyethylene
Explanation - PLA can be sourced from corn starch or sugarcane, and its mechanical properties are suitable for microneedle fabrication.
Correct answer is: Polylactic acid (PLA)
Q.48 In the context of biodegradable carriers, the term “hydrophilic–hydrophobic balance” primarily influences:
Electrical resistivity
Drug loading efficiency and release rate
Magnetic permeability
Thermal conductivity
Explanation - Balancing water‑affinity and water‑repellence determines how well a drug partitions into the polymer and how quickly it diffuses out.
Correct answer is: Drug loading efficiency and release rate
Q.49 Which of the following is a typical sign of poor biocompatibility when a biodegradable implant is examined histologically after implantation?
Uniform tissue integration without inflammation
Dense fibrous capsule formation around the implant
Increased blood vessel formation (angiogenesis)
Presence of healthy fibroblasts
Explanation - A thick fibrous capsule indicates a foreign‑body reaction, a hallmark of inadequate biocompatibility.
Correct answer is: Dense fibrous capsule formation around the implant
Q.50 A biodegradable carrier designed to release a peptide drug over a 2‑week period would most likely use which of the following strategies?
Incorporating a high proportion of glycolic acid in PLGA (e.g., 50:50)
Embedding the peptide in a highly crystalline PCL matrix
Coating the carrier with a non‑degradable silicone layer
Using a purely hydrophobic polymer without any hydrophilic segments
Explanation - Higher glycolic content speeds hydrolysis, matching the desired 2‑week release profile.
Correct answer is: Incorporating a high proportion of glycolic acid in PLGA (e.g., 50:50)
Q.51 Which of the following is NOT a typical method for evaluating the mechanical integrity of a biodegradable scaffold?
Compression testing
Tensile testing
Cyclic fatigue testing
UV–Vis absorbance spectroscopy
Explanation - UV–Vis measures optical properties, not mechanical strength.
Correct answer is: UV–Vis absorbance spectroscopy
Q.52 When a biodegradable polymer is exposed to plasma sterilization, the most likely effect on its degradation behavior is:
Complete inhibition of degradation
Cross‑linking that slows degradation
Chain scission that accelerates degradation
No effect at all
Explanation - Plasma can break polymer chains, reducing molecular weight and increasing hydrolysis rates.
Correct answer is: Chain scission that accelerates degradation
Q.53 Which biodegradable polymer is known for its rapid degradation (days to weeks) and is often used for short‑term drug delivery in the eye?
Polylactic acid (PLA)
Poly(ε‑caprolactone) (PCL)
Polyhydroxyalkanoate (PHA)
Poly(lactic‑co‑glycolic acid) (PLGA) with high glycolic content
Explanation - High glycolic acid ratios increase hydrophilicity, leading to faster hydrolysis suitable for ocular applications.
Correct answer is: Poly(lactic‑co‑glycolic acid) (PLGA) with high glycolic content
Q.54 A biodegradable carrier that is engineered to release its drug payload in response to a change in pH is called:
Thermo‑responsive
pH‑responsive (or pH‑sensitive)
Magneto‑responsive
Electro‑responsive
Explanation - pH‑responsive carriers contain acid‑labile bonds or ionizable groups that trigger release under specific pH conditions.
Correct answer is: pH‑responsive (or pH‑sensitive)
Q.55 Which of the following is an advantage of using a biodegradable polymeric microsphere over a non‑degradable one for vaccine delivery?
Higher electrical conductivity
Elimination of a second surgery to remove the carrier after antigen release
Ability to generate a permanent magnetic field
Infinite shelf life
Explanation - Biodegradable microspheres naturally dissolve after delivering the antigen, improving patient compliance.
Correct answer is: Elimination of a second surgery to remove the carrier after antigen release
Q.56 The term “bioadhesion” in drug delivery refers to:
Electrical adhesion of polymers
The ability of a carrier to adhere to biological tissues, prolonging residence time
Magnetic attraction between the carrier and blood cells
Optical adhesion observed under a microscope
Explanation - Bioadhesive polymers interact with mucosal surfaces, enhancing drug absorption.
Correct answer is: The ability of a carrier to adhere to biological tissues, prolonging residence time
Q.57 Which of the following would most likely increase the immunogenicity of a biodegradable carrier?
Incorporating immunologically inert PEG chains
Using a highly purified, endotoxin‑free polymer
Residual solvent or unreacted monomer remaining after synthesis
Surface grafting with zwitterionic polymers
Explanation - Impurities can provoke immune responses, compromising biocompatibility.
Correct answer is: Residual solvent or unreacted monomer remaining after synthesis
Q.58 A biodegradable polymer that exhibits shape change upon exposure to a specific enzyme is best classified as:
Thermoplastic
Enzyme‑responsive (or enzymatically degradable)
Electroactive
Photolabile
Explanation - Enzyme‑responsive polymers are designed to degrade or change structure when encountering target enzymes.
Correct answer is: Enzyme‑responsive (or enzymatically degradable)
Q.59 Which of the following polymers is most suitable for creating a biodegradable scaffold that mimics the mechanical properties of native cartilage?
Polyethylene terephthalate (PET)
Poly(lactide‑co‑glycolide) (PLGA) with a high lactic acid ratio
Polytetrafluoroethylene (PTFE)
Polypropylene (PP)
Explanation - Higher lactic content yields a stiffer, slower‑degrading polymer, approximating cartilage stiffness.
Correct answer is: Poly(lactide‑co‑glycolide) (PLGA) with a high lactic acid ratio
Q.60 During in‑vitro degradation studies of a biodegradable polymer, an increase in the solution’s conductivity is most likely due to:
Release of ionic degradation products such as lactic acid ions
Loss of polymer mass only
Temperature rise of the medium
Formation of gas bubbles
Explanation - Acidic monomers ionize in solution, increasing its electrical conductivity.
Correct answer is: Release of ionic degradation products such as lactic acid ions
Q.61 Which of the following is a primary challenge when designing biodegradable carriers for nucleic acid (DNA/RNA) delivery?
Ensuring the carrier is magnetic
Protecting the nucleic acid from nuclease degradation while facilitating intracellular release
Making the carrier electrically conductive
Achieving optical transparency
Explanation - Carriers must shield genetic material from enzymes yet release it once inside target cells.
Correct answer is: Protecting the nucleic acid from nuclease degradation while facilitating intracellular release
Q.62 In a biodegradable polymeric depot, a lag phase before drug release is most commonly associated with:
Initial water uptake and polymer swelling
Immediate surface erosion
Rapid polymer degradation
Magnetic field application
Explanation - Swelling precedes hydrolysis, causing a temporary delay before drug diffusion begins.
Correct answer is: Initial water uptake and polymer swelling
Q.63 Which of the following would most likely improve the mechanical strength of a biodegradable scaffold without significantly slowing its degradation?
Increasing crystallinity by annealing
Adding a small amount of bio‑ceramic particles (e.g., hydroxyapatite)
Cross‑linking with a high‑density chemical cross‑linker
Coating with a non‑degradable polymer
Explanation - Ceramic fillers reinforce the matrix while maintaining overall degradability.
Correct answer is: Adding a small amount of bio‑ceramic particles (e.g., hydroxyapatite)
Q.64 A polymeric carrier that is designed to dissolve in response to a specific wavelength of light is called:
Thermo‑responsive
Photodegradable (or photo‑responsive)
Magneto‑responsive
Electro‑responsive
Explanation - Photodegradable polymers contain light‑sensitive bonds that cleave upon illumination, triggering dissolution.
Correct answer is: Photodegradable (or photo‑responsive)
Q.65 Which of the following best describes the role of “hydrogel” in biodegradable drug delivery systems?
A rigid, non‑degradable scaffold
A water‑rich, cross‑linked polymer network that can swell and release drugs
A metallic implant that conducts electricity
A glassy polymer that does not interact with water
Explanation - Hydrogels absorb large amounts of water, allowing diffusion‑controlled drug release while being biodegradable.
Correct answer is: A water‑rich, cross‑linked polymer network that can swell and release drugs
Q.66 In the design of a biodegradable carrier for pulmonary delivery, which particle property is most critical for deep lung deposition?
Density > 2 g/cm³
Aerodynamic diameter of 1–5 µm
Magnetic susceptibility
High surface roughness
Explanation - Particles within this aerodynamic size range bypass the upper airways and reach the alveolar region.
Correct answer is: Aerodynamic diameter of 1–5 µm
Q.67 Which analytical technique is best suited for visualizing the internal porous structure of a biodegradable scaffold?
Transmission electron microscopy (TEM)
Scanning electron microscopy (SEM)
X‑ray diffraction (XRD)
Fourier‑transform infrared spectroscopy (FTIR)
Explanation - SEM provides high‑resolution images of surface and cross‑sectional morphology, revealing pore size and interconnectivity.
Correct answer is: Scanning electron microscopy (SEM)
Q.68 A biodegradable polymer with a low glass transition temperature (Tg) near body temperature is likely to:
Remain completely rigid after implantation
Become more flexible and possibly increase drug diffusion rates at physiological temperature
Conduct electricity more efficiently
Resist hydrolytic degradation
Explanation - When Tg ≈ 37 °C, the polymer transitions to a rubbery state, enhancing chain mobility and drug diffusion.
Correct answer is: Become more flexible and possibly increase drug diffusion rates at physiological temperature
Q.69 Which of the following is a common cause of batch‑to‑batch variability in the degradation rate of biodegradable polymeric carriers?
Changes in ambient humidity during storage
Differences in polymer molecular weight distribution and residual monomer content
Variations in the color of the polymer
Fluctuations in ambient magnetic fields
Explanation - Molecular weight and unreacted monomers directly affect hydrolysis kinetics, leading to variability.
Correct answer is: Differences in polymer molecular weight distribution and residual monomer content
Q.70 Which of the following strategies can be employed to reduce the initial burst release from a biodegradable nanoparticle system?
Increasing surface roughness
Encapsulating drug deeper within the polymer matrix and using a coating layer
Adding surfactants to the formulation
Using a lower polymer concentration
Explanation - Deeper drug entrapment and surface coating limit immediate diffusion of surface‑adsorbed drug.
Correct answer is: Encapsulating drug deeper within the polymer matrix and using a coating layer
Q.71 Which of the following polymers is known for its inherent antimicrobial properties, making it attractive for wound‑healing applications?
Chitosan
Polyethylene glycol (PEG)
Polystyrene
Polyvinyl chloride (PVC)
Explanation - Chitosan disrupts bacterial cell membranes, providing antimicrobial activity while being biodegradable.
Correct answer is: Chitosan
Q.72 A biodegradable carrier that releases its drug payload upon exposure to a specific enzyme overexpressed in inflamed tissue is an example of:
Thermo‑responsive delivery
Enzyme‑triggered release
Magnetically guided delivery
Electrically stimulated release
Explanation - Enzyme‑sensitive linkages degrade in the presence of target enzymes, providing site‑specific drug release.
Correct answer is: Enzyme‑triggered release
Q.73 In a biodegradable polymeric depot, the term “lag phase” refers to:
The period where no drug is released because the polymer has not yet absorbed sufficient water to initiate degradation
A period of rapid drug release
The time needed for the polymer to become electrically conductive
The phase where the polymer changes color
Explanation - Lag phase is due to initial water uptake before hydrolysis and diffusion can start.
Correct answer is: The period where no drug is released because the polymer has not yet absorbed sufficient water to initiate degradation
Q.74 Which of the following biodegradable polymers is commonly used for creating absorbable sutures?
Polylactic acid (PLA)
Polyethylene (PE)
Polycarbonate (PC)
Polyvinyl chloride (PVC)
Explanation - PLA’s predictable degradation profile and sufficient tensile strength make it suitable for absorbable sutures.
Correct answer is: Polylactic acid (PLA)
Q.75 The presence of which functional group in a polymer backbone typically reduces its overall biodegradability?
Ester (–COO–)
Amide (–CONH–)
Ether (–O–)
Aromatic carbon‑carbon (C–C) bonds
Explanation - Aromatic C–C bonds are resistant to hydrolysis and enzymatic attack, slowing degradation.
Correct answer is: Aromatic carbon‑carbon (C–C) bonds
Q.76 Which of the following is an advantage of using a biodegradable polymeric microneedle patch for transdermal drug delivery?
Requirement of surgical implantation
Potential for painless administration and complete dissolution after drug delivery
Long‑term electrical stimulation
Generation of magnetic fields
Explanation - Microneedles penetrate the skin minimally and dissolve, delivering drug without leaving residues.
Correct answer is: Potential for painless administration and complete dissolution after drug delivery
Q.77 When assessing the long‑term stability of a biodegradable drug carrier, which factor is most critical to monitor?
Changes in polymer molecular weight over storage time
The carrier’s color under UV light
Electrical resistance in dry air
Magnetic susceptibility at room temperature
Explanation - Molecular weight reduction can indicate premature degradation, affecting shelf‑life and performance.
Correct answer is: Changes in polymer molecular weight over storage time
Q.78 Which of the following biodegradable polymers is often combined with gelatin to enhance cell adhesion in tissue‑engineered scaffolds?
Poly(lactide‑co‑glycolide) (PLGA)
Polyethylene terephthalate (PET)
Polyvinyl chloride (PVC)
Polytetrafluoroethylene (PTFE)
Explanation - PLGA provides structural support while gelatin adds bioactive motifs for cell attachment.
Correct answer is: Poly(lactide‑co‑glycolide) (PLGA)
Q.79 Which of the following mechanisms is primarily responsible for the controlled release of a hydrophilic drug from a hydrophobic biodegradable polymer matrix?
Electrical conduction
Diffusion through water‑filled pores created by polymer degradation
Magnetic attraction
Thermal expansion
Explanation - Hydrophilic drugs diffuse through aqueous channels that develop as the polymer degrades.
Correct answer is: Diffusion through water‑filled pores created by polymer degradation
Q.80 In a biodegradable polymer, an increase in the proportion of crystalline domains generally leads to:
Faster degradation rate
Slower degradation rate
Higher electrical conductivity
Increased water solubility
Explanation - Crystalline regions are less accessible to water, reducing hydrolysis speed.
Correct answer is: Slower degradation rate
Q.81 Which of the following is a typical in‑vivo model for evaluating the degradation and tissue response of an implanted biodegradable scaffold?
Subcutaneous implantation in rats or mice
In‑vitro cell culture on a petri dish
Computational simulation only
Spectrophotometric analysis of polymer extracts
Explanation - Subcutaneous models allow assessment of degradation kinetics and host tissue response in a living system.
Correct answer is: Subcutaneous implantation in rats or mice
Q.82 A biodegradable polymer carrier that releases its drug payload in response to a temperature rise from 37 °C to 42 °C is classified as:
pH‑responsive
Thermo‑responsive
Magneto‑responsive
Electro‑responsive
Explanation - Thermo‑responsive polymers change their physical state or permeability with temperature, enabling temperature‑triggered release.
Correct answer is: Thermo‑responsive
Q.83 Which of the following is a potential disadvantage of using high‑molecular‑weight PLGA for drug delivery?
Too rapid drug release
Insufficient mechanical strength
Potential for acidic microenvironment due to slow degradation products
Inability to be sterilized
Explanation - Accumulation of lactic and glycolic acids from slow‑degrading PLGA can lower local pH, affecting drug stability and cell viability.
Correct answer is: Potential for acidic microenvironment due to slow degradation products
Q.84 Which of the following polymerization techniques is commonly used to synthesize biodegradable polyesters like PLA and PLGA?
Free‑radical polymerization
Ring‑opening polymerization (ROP)
Anionic polymerization
Condensation polymerization of vinyl monomers
Explanation - ROP of lactide and glycolide monomers yields high‑purity polyesters with controlled molecular weights.
Correct answer is: Ring‑opening polymerization (ROP)
Q.85 A biodegradable polymer that exhibits a rapid initial release followed by a slower, sustained release is said to follow:
Zero‑order kinetics only
Biphasic release kinetics
First‑order kinetics only
Magnetic release kinetics
Explanation - The initial burst and subsequent slower phase constitute a biphasic release profile.
Correct answer is: Biphasic release kinetics
Q.86 Which of the following is a common reason for adding a surfactant (e.g., PVA) during the preparation of biodegradable polymeric nanoparticles?
To increase the polymer’s crystallinity
To stabilize the emulsion and prevent particle aggregation
To make the particles magnetic
To change the polymer’s color
Explanation - Surfactants reduce interfacial tension, leading to uniform particle size and stability.
Correct answer is: To stabilize the emulsion and prevent particle aggregation
Q.87 In the context of biodegradable carriers, the term “stealth” is most closely associated with:
Invisible to the naked eye
Surface modification that reduces protein adsorption and prolongs circulation time
Ability to conduct electricity without loss
Having a magnetic core
Explanation - Stealth coatings (e.g., PEG) hide the carrier from the immune system, extending its half‑life.
Correct answer is: Surface modification that reduces protein adsorption and prolongs circulation time
Q.88 Which of the following polymers is best suited for creating a biodegradable scaffold that degrades within a few days for short‑term wound dressing applications?
Polycaprolactone (PCL)
Polylactic acid (PLA)
Poly(lactic‑co‑glycolic acid) (PLGA) with high glycolic content (e.g., 75:25)
Polyethylene (PE)
Explanation - Higher glycolic ratios increase hydrophilicity and accelerate hydrolysis, achieving rapid degradation.
Correct answer is: Poly(lactic‑co‑glycolic acid) (PLGA) with high glycolic content (e.g., 75:25)
Q.89 A biodegradable polymer that can form a gel at body temperature after injection is most likely composed of:
A thermosensitive block copolymer such as PLGA‑PEG‑PLGA
A highly crystalline polyester
A metallic alloy
A hydrophobic silicone oil
Explanation - Thermosensitive block copolymers undergo sol‑to‑gel transition near 37 °C, enabling in‑situ depot formation.
Correct answer is: A thermosensitive block copolymer such as PLGA‑PEG‑PLGA
Q.90 Which of the following analytical techniques provides quantitative data on the amount of residual monomer in a biodegradable polymer batch?
Gas chromatography (GC)
Scanning electron microscopy (SEM)
X‑ray diffraction (XRD)
Fourier‑transform infrared spectroscopy (FTIR)
Explanation - GC can separate and quantify volatile monomers remaining after polymer synthesis.
Correct answer is: Gas chromatography (GC)
Q.91 In the design of biodegradable carriers for oral vaccines, why is it advantageous to use an enteric coating?
To protect the carrier from stomach acid and release it in the intestine
To make the carrier magnetic
To increase the carrier’s electrical conductivity
To give the carrier a bright color
Explanation - Enteric coatings are resistant to low pH but dissolve at higher intestinal pH, preserving antigen integrity.
Correct answer is: To protect the carrier from stomach acid and release it in the intestine
Q.92 Which of the following is a key factor that influences the rate of enzymatic degradation of a biodegradable polymer in vivo?
Polymer’s magnetic susceptibility
Presence of specific cleavage sites recognized by the enzyme
Polymer’s optical clarity
Polymer’s electrical conductivity
Explanation - Enzymes degrade polymers that contain sequences they can recognize and cleave.
Correct answer is: Presence of specific cleavage sites recognized by the enzyme
Q.93 Which of the following statements best describes the relationship between polymer degradation and drug release for an erosion‑controlled system?
Drug release is independent of polymer degradation
Drug release rate mirrors the polymer erosion rate, often yielding zero‑order kinetics
Drug release only occurs after the polymer is completely degraded
Drug release occurs only during the initial burst phase
Explanation - In erosion‑controlled systems, the drug is released as the polymer matrix erodes, leading to a relatively constant release rate.
Correct answer is: Drug release rate mirrors the polymer erosion rate, often yielding zero‑order kinetics
Q.94 Which of the following is a potential advantage of using a biodegradable polymeric scaffold that mimics the extracellular matrix (ECM) for tissue engineering?
It permanently replaces the native tissue
It provides temporary mechanical support while allowing natural tissue regeneration as it degrades
It conducts electricity to stimulate cells
It creates a permanent barrier to prevent cell infiltration
Explanation - ECM‑mimicking scaffolds guide cell growth and gradually disappear as new tissue forms.
Correct answer is: It provides temporary mechanical support while allowing natural tissue regeneration as it degrades
Q.95 A biodegradable polymer carrier intended for intramuscular injection should preferably have:
A particle size larger than 10 µm to avoid rapid clearance
A surface charge that is highly positive to promote muscle tissue damage
A formulation that can form a depot and release drug over weeks to months
Magnetic properties to be guided by an external magnet
Explanation - Depot‑forming carriers enable sustained drug exposure at the injection site, reducing dosing frequency.
Correct answer is: A formulation that can form a depot and release drug over weeks to months
Q.96 Which of the following is a common method to evaluate the in‑vitro degradation rate of a biodegradable polymer film?
Measuring weight loss after immersion in phosphate‑buffered saline (PBS) over time
Recording the film’s electrical resistance
Observing the film’s color change under UV light
Measuring its magnetic moment
Explanation - Weight loss correlates with polymer dissolution and provides a straightforward degradation metric.
Correct answer is: Measuring weight loss after immersion in phosphate‑buffered saline (PBS) over time
Q.97 Which property of a biodegradable polymer is most directly related to its ability to be sterilized by gamma irradiation without significant loss of mechanical strength?
High crystallinity
Low molecular weight
Presence of aromatic rings
Hydrophilicity
Explanation - Highly crystalline polymers can better resist chain scission induced by gamma irradiation, preserving mechanical integrity.
Correct answer is: High crystallinity
Q.98 When a biodegradable polymeric carrier is designed for targeted delivery to cancer cells, which surface modification is most commonly employed?
Attachment of folic acid or antibodies specific to tumor cell receptors
Coating with a thick layer of gold
Embedding magnetic nanoparticles without any targeting ligand
Adding a bright fluorescent dye
Explanation - Ligands such as folic acid bind to overexpressed receptors on cancer cells, enhancing selective uptake.
Correct answer is: Attachment of folic acid or antibodies specific to tumor cell receptors
Q.99 Which of the following statements best explains why a biodegradable polymer with a high water uptake capacity may exhibit faster drug release?
Water creates conductive pathways for electrons
Swelling increases polymer chain mobility and creates aqueous channels for diffusion
Water changes the polymer’s magnetic properties
Water decreases the polymer’s density
Explanation - Increased water content expands the polymer matrix, facilitating drug diffusion and hydrolytic degradation.
Correct answer is: Swelling increases polymer chain mobility and creates aqueous channels for diffusion
Q.100 A biodegradable polymer that degrades via bulk erosion rather than surface erosion typically shows:
Uniform mass loss throughout the material and a relatively constant release rate until the structure collapses
Only the outermost layer degrades while the interior remains intact
Immediate complete dissolution
No degradation at all
Explanation - Bulk erosion involves water penetrating the entire matrix, leading to homogeneous degradation.
Correct answer is: Uniform mass loss throughout the material and a relatively constant release rate until the structure collapses
Q.101 Which of the following biodegradable carriers would be most appropriate for delivering a hydrophobic anticancer drug that requires prolonged systemic circulation?
PEGylated PLGA nanoparticles
Hydrophilic chitosan nanogels
Pure PCL microspheres without surface modification
Hydrogel beads made of alginate
Explanation - PEGylation extends circulation time, while PLGA provides a suitable hydrophobic matrix for the drug.
Correct answer is: PEGylated PLGA nanoparticles
Q.102 Which of the following is a potential drawback of using a highly porous biodegradable scaffold for bone regeneration?
Insufficient surface area for cell attachment
Reduced mechanical strength that may not support load‑bearing applications
Excessive electrical conductivity
Inability to degrade
Explanation - While porosity promotes tissue ingrowth, it can compromise structural integrity required for bone support.
Correct answer is: Reduced mechanical strength that may not support load‑bearing applications
Q.103 A biodegradable polymer carrier that releases drug upon exposure to ultrasound is utilizing which type of stimulus?
Mechanical
Thermal
Acoustic
Magnetic
Explanation - Ultrasound generates acoustic waves that can disrupt the polymer matrix, triggering drug release.
Correct answer is: Acoustic
Q.104 Which of the following is a common reason for the formation of an acidic microenvironment around degrading PLGA implants?
Generation of lactic and glycolic acid as degradation products
Release of basic amine groups
Absorption of atmospheric CO₂
Production of metallic ions
Explanation - Hydrolysis of PLGA yields acidic monomers, potentially lowering local pH.
Correct answer is: Generation of lactic and glycolic acid as degradation products
Q.105 Which of the following biodegradable polymers is most commonly used for creating drug‑eluting stents?
Poly(lactic‑co‑glycolic acid) (PLGA)
Polyethylene terephthalate (PET)
Polytetrafluoroethylene (PTFE)
Polypropylene (PP)
Explanation - PLGA’s controllable degradation and biocompatibility make it suitable for temporary stent coatings that release drugs.
Correct answer is: Poly(lactic‑co‑glycolic acid) (PLGA)
Q.106 A biodegradable carrier designed to release an anti‑inflammatory drug specifically in inflamed joints should ideally be:
Responsive to elevated levels of reactive oxygen species (ROS)
Magnetically attracted to the joint space
Highly hydrophobic to avoid water uptake
Opaque to X‑rays
Explanation - Inflamed tissues often have higher ROS; ROS‑sensitive carriers degrade preferentially in these areas.
Correct answer is: Responsive to elevated levels of reactive oxygen species (ROS)
Q.107 Which of the following statements correctly describes why poly(ε‑caprolactone) (PCL) is often blended with faster degrading polymers for drug delivery?
PCL is too brittle on its own
PCL degrades too quickly for most therapeutic timelines
Blending reduces the overall degradation time, achieving a balanced release profile
PCL is not approved by regulatory agencies
Explanation - PCL’s slow degradation can be accelerated by mixing with faster‑degrading polymers, tailoring release kinetics.
Correct answer is: Blending reduces the overall degradation time, achieving a balanced release profile
Q.108 In a biodegradable polymeric depot, which phenomenon explains a sudden increase in drug release after a period of slow release?
Polymer crystallization
Polymer swelling and pore formation leading to a percolation threshold
Magnetic field activation
Temperature drop
Explanation - When enough pores interconnect, diffusion pathways open suddenly, increasing drug release rate.
Correct answer is: Polymer swelling and pore formation leading to a percolation threshold
Q.109 Which of the following is a major factor influencing the immune response to a biodegradable polymeric implant?
Polymer’s electrical conductivity
Surface chemistry and presence of immunogenic epitopes
Magnetic susceptibility
Optical reflectivity
Explanation - Surface functional groups can be recognized by immune cells, dictating the magnitude of the response.
Correct answer is: Surface chemistry and presence of immunogenic epitopes
Q.110 A biodegradable polymeric micelle that remains stable in blood plasma but releases its drug payload in the acidic environment of a tumor is utilizing:
pH‑responsive behavior
Thermal responsiveness
Magnetic responsiveness
Electrostatic repulsion
Explanation - Acidic tumor pH triggers destabilization of pH‑sensitive micelles, leading to drug release.
Correct answer is: pH‑responsive behavior
Q.111 Which of the following best explains why a biodegradable polymer with a high degree of hydrophilicity may have a faster degradation rate?
Hydrophilic polymers attract more water, facilitating hydrolysis of polymer bonds
Hydrophilic polymers conduct electricity better
Hydrophilic polymers are less visible to the immune system
Hydrophilic polymers have higher melting points
Explanation - Greater water uptake accelerates hydrolytic cleavage of ester bonds in the polymer backbone.
Correct answer is: Hydrophilic polymers attract more water, facilitating hydrolysis of polymer bonds
Q.112 When a biodegradable polymeric scaffold is intended for cardiac tissue engineering, which property is most critical?
Electrical conductivity to support cardiomyocyte synchronization
Magnetic permeability
High optical opacity
Very slow degradation over years
Explanation - Conductive scaffolds facilitate electrical signal propagation, essential for functional cardiac tissue.
Correct answer is: Electrical conductivity to support cardiomyocyte synchronization