24. Nanofibers for Medical Diagnosis and Therapy

Nanofibers are fibers having dimensions in the nanometric range of few tens to 1000 nm. Advantages of nanofibers include their high surface-area-to-volume ratio resulting in enhanced drug solubility, high porosity, superior mechanical strength, versatile surface functionalization, and similarity to the extracellular matrix which promotes their use as wound dressings. Nanofibers have demonstrated their biomedical prowess in the fields of diagnosis as well as therapy. Nanofibers have been explored as ultrasensitive biosensors for point-of-care diagnosis of cancer, detection of circulating tumor cells in cancer patients, diagnosis of malaria, and detection of urea, glucose, cholesterol, bacteria, etc. Their huge surface area offers large number of binding sites thus endowing them with the capability for ultrasensitive detection. Nanofibers have also exhibited promising potential as drug delivery carriers and as wound dressings. Smart nanofibers which release the drug in response to stimuli such as pH, temperature, magnetic field, ultrasound waves, enzyme, and light have been studied to cater to the need for on-demand drug release systems. Nanofibers for photodynamic therapy have also been reported. Multifunctional nanofibers have also been developed for combined hyperthermia and therapy. Nanofibers may be fabricated using natural or synthetic polymers and using synthetic drugs as well as herbal molecules and extracts. Drug release from nanofibers can be modified based on the choice of polymer and the method of drug loading. Nanofibers have been developed for administration through various routes such as oral, oromucosal, periodontal, transdermal, intravenous, ophthalmic, vaginal, etc. The chapter showcases the potential applications of nanofibers in medical diagnosis and therapy.