Carbohydrate polymers are gaining popularity recently due to their abundance, tendency to form supramolecular structures, hydrophilicity, ability to form hydrogen and hydrophobic bonds, eco-friendliness, biocompatibility, biodegradability, renewable origin, and facile modification into polymeric systems. Modification of these materials leads to various properties with wider applications in various fields. In this chapter, we focus on cellulose, chitin, chitosan and alginate or their combinations into nanofiber form and their applications in nanobiotechnology. Nano-delivery systems in the food sector (food preservation and food fortification), agricultural sector (controlled release of agrochemicals using nature-derived polymers), drug delivery to specific tissues, and pickering emulsion stabilizers are highlighted.