Can nanoparticles permeate cell membranes better than small lipophilic molecules in solution?
No — lipophilic molecules diffuse readily; nanoparticles must be uptaken by cells.
Do glucose and small ions like calcium require transporter proteins to cross the plasma membrane?
Yes — even though small, they need transporters because they don’t diffuse easily.
Can small hydrophilic molecules (<500 Da) cross membranes without transporters?
No — charged or polar molecules cannot cross the lipid bilayer freely.
Which molecules benefit most from nanoparticle delivery?
Molecules that are degraded by enzymes or are poorly permeable.
Why don’t well-permeable small molecules benefit from nanoparticles?
They already cross membranes easily; attaching nanoparticles would reduce permeability.
How do nanoparticles help molecules degraded extracellularly or intracellularly?
They protect the drug from enzymatic degradation, reducing clearance.
How do nanoparticles help poorly permeable molecules?
They enhance cellular uptake through endocytosis or transport mechanisms.
Why do antibodies circulate longer in the bloodstream?
They are large (>4 nm, above glomerular filtration cutoff) and hydrophilic, so not rapidly cleared by kidney or liver.
Why are hydrophilic molecules less cleared by the liver?
The liver clears hydrophobic substances more efficiently.
What properties of viruses allow them to infect remote body parts?
Surface proteins that enable cell entry
Dose amplification via replication in host cells
What allows bacteria to cross barriers and infect remote sites?
Endotoxins that increase permeability
Replication that amplifies dose
What does enhanced permeation and retention (EPR) mean in cancer nanotherapy?
Tumor vasculature is leaky (↑ permeability) and has poor lymphatic drainage (↑ retention), leading to nanoparticle accumulation.
How does particle size affect cellular uptake?
As particle size increases, cellular uptake decreases.
Which has a more prolonged drug release — nanoparticles or microparticles?
Microparticles, due to smaller surface area–to–volume ratio.
For gene delivery (intracellular target), which is better: nanoparticles or microparticles?
Nanoparticles — easier for cellular uptake of hydrophilic macromolecules.
Do mRNA vaccines for SARS-CoV-2 use nanoparticles or microparticles?
Nanoparticles.
Which particles settle faster in suspension: nanoparticles or microparticles?
Microparticles — larger particles settle faster.
Why do nanoparticles remain suspended longer than microparticles?
Smaller size and increased Brownian motion.
For a long-term (6-month) corticosteroid eye treatment, which is better — nanoparticle or microparticle?
Microparticle — larger size provides longer release.
Which type collides more often with cell surface receptors — nanoparticles or microparticles?
Nanoparticles, due to higher Brownian movement and surface activity.
What are the benefits of paclitaxel-albumin nanoparticles (Abraxane) over paclitaxel in Cremophor EL (Taxol)?
No solvent toxicity
No corticosteroids/antihistamines needed
Shorter infusion time
1.5× higher tolerated dose
2× better response rate
What materials are commonly used to make nanoparticles?
Pure drug particles
Drug–carrier composites
Carriers: lipids, proteins, polymers
Stabilizers for particle size control
Do sticky, rapidly uptaken nanoparticles improve ocular delivery of poorly permeable drugs?
No — if the drug itself can’t permeate, sticking longer won’t help absorption.
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biochem quiz 199
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ocular delivery54
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inhaled drugs63
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nanoparticles23
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simburg powders and capsules93
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simburg excipients and tabs92
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simburg controlled release79
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simburg parenterals and biologics78
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simburg excipient questions and trends81
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Wolcott lecture 176
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Wolcott lecture 256
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Wolcott lecture 344
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Kiser lecture 4 - Absorption78
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Freitas lecture 5 - skin absorption and transdermals53
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Freitas lecture 6 - skin absorption and transdermals54
