Related by context. Frequent words. (Click for all words.) 79 cell membranes 70 membrane 69 molecule 68 molecules 64 proteins 64 membranes 64 vesicles 62 epithelial cells 62 cytoplasm 61 tumor cells 61 nerve cells 61 intracellular 60 endothelial cells 59 cells 59 synapse 59 ligand 59 capillaries 59 lipids 58 nerve fibers 57 nanotubes 57 axons 57 gastrointestinal tract 57 protease 57 blood vessels 56 neurons 56 actin 56 electrons 56 filaments 56 nanoparticles 56 GI tract 56 peptides 55 bloodstream 55 nanotube 55 immune cells 55 peptide 55 receptors 55 chromatin 55 mitochondria 55 ions 55 hydrophobic 55 ligands 54 neuron 54 biomolecules 54 molecular 54 small intestine 54 receptor 54 enzyme 54 protein 54 hydrogen atoms 54 macrophages 54 nanoparticle 54 enzymes 54 atoms 54 nanowire 54 lipid 54 motor neurons 54 ion channels 53 dendritic cells 53 digestive tract 53 tissues 53 signaling pathway 53 intestine 53 particles 53 substrate 52 intestinal tract 52 neurotransmitter 52 quantum dots 52 nuclei 52 ion channel 52 phosphorylation 52 polymer 52 astrocytes 52 amino acids 52 mucous membranes 52 nanostructures 51 fibroblasts 51 neutrophils 51 carbon atoms 51 filament 51 neurotransmitters 51 electron 51 capillary 51 electrode 51 biofilm 51 nanoscale 51 intestines 51 myelin 51 droplet 51 amino acid 51 bacterium 51 outer layer 51 nanowires 50 signaling pathways 50 photons 50 malignant cells 50 organic molecules 50 cancerous cells 50 epidermis 50 connective tissue 50 nucleic acids 50 mRNA