Boronic acids are able to reversibly interact with the diol groups, a commonly found motif in biomolecules including sugars, ribose and catechols. For their carbohydrate-binding properties, they can be regarded as a synthetic mimic of lectins and often termed as “borono-lectins.” Importantly, the borono-lectins platform can be chemically tailored to manifest a broad profile of binding strength and specificity. Besides the structural versatility, some derivatives can undergo a sharp inversion in the state of hydration in synchronization with the molecular recognitions. This feature, when combined with amphiphilic polymeric backbones, translates into many creative principles for fine-tuning or switching the hydration and more complex molecular assemblies in a way interactive with biology. Here we provide a brief overview of our recent efforts on the related applications with special focuses on smart insulin delivery systems and sialic acid detections relevant to cancer diagnosis and treatment among others.