Sustainable materials are key to the continual improvement of living standards on this planet with minimal environmental impacts. Nanocellulose combines the fascinating features of nanomaterials with favorable properties of the abundantly available cellulose biopolymer, which in recent years has gained much attention toward biomedical applications by virtue of its unique surface chemistry, remarkable physical features, and inherent biological attributes. Herein, the recent advances in nanocellulose‐based biomedical materials, with foci on biomolecule immobilization, drug delivery, cell culture and tissue engineering (TE), antimicrobial strategy, wound healing, and biomedical implants are summarized. Each topic is elaborated with representative examples to present the significance of nanocelluloses in their respective material design principles utilizing different sub‐types, including cellulose nanofibers (CNFs), cellulose nanocrystals (CNCs), and bacterial nanocellulose (BNC). The current state of large‐scale production of nanocellulose and accelerated development by artificial intelligence and machine learning are also briefly discussed, before ending with its future prospects and potential challenges.

Supramolecules have been drawing increasing attention recently in addressing healthcare challenges caused by infectious pathogens. We herein report a novel class of guanidinium-perfunctionalized polyhedral oligomeric silsesquioxane (Gua-POSS) supramolecules with highly potent antimicrobial activities. The modular structure of Gua-POSS Tm-Cn consists of an inorganic T10 or T8 core (m = 10 or 8), flexible linear linkers of varying lengths (n = 1 or 3), and peripherally aligned cationic guanidinium groups as the membrane-binding units. Such Gua-POSS supramolecules with spherically arrayed guanidinium cations display high antimicrobial potency against Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli) bacteria, as well as fungus (Candida albicans), with the best showing excellently low minimal inhibitory concentrations (MICs) of 1.7−6.8 μM in media, yet with negligible hemolytic activity and low in vitro cytotoxicity to mammalian cells. More significantly, they can inhibit biofilm formation at around their MICs and near-completely break down preestablished difficult-to-break biofilms at 250 μg mL −1 (∼50 μM). Their strong antiviral efficacy was also experimentally demonstrated against the enveloped murine hepatitis coronavirus as a surrogate of the SARS-CoV species. Overall, this study provides a new design approach to novel classes of sphere-shaped organic−inorganic hybrid supramolecular materials, especially for potent antimicrobial, anti-biofilm, and antiviral applications.