Graphene materials have unique structures and outstanding thermal, optical, mechanical and electronic properties. In the last decade, these materials have attracted substantial interest in the field of nanomaterials, with applications ranging from biosensors to biomedicine. Among these applications, great advances have been made in the field of antibacterial agents. Here, recent advancements in the use of graphene and its derivatives as antibacterial agents are reviewed. Graphene is used in three forms: the pristine form; mixed with other antibacterial agents, such as Ag and chitosan; or with a base material, such as poly (N-vinylcarbazole) (PVK) and poly (lactic acid) (PLA). The main mechanisms proposed to explain the antibacterial behaviors of graphene and its derivatives are the membrane stress hypothesis, the oxidative stress hypothesis, the entrapment hypothesis, the electron transfer hypothesis and the photothermal hypothesis. This review describes contributions to improving these promising materials for antibacterial applications.

Hydrogels with self-healing features that can spontaneously repair themselves upon mechanical damage are increasingly attractive for biomedical applications. Many attempts have been made to develop unique hydrogels possessing this property, as well as stimuli-responsiveness and biocompatibility; however, the hydrogel fabrication strategies often involve specific design of functional monomers that are able to optimally provide reversible physical or chemical interactions. Here, we report that weak hydrogen bonds, provided by oligo(ethylene glycol) methacrylate (OEGMA) and methacrylic acid (MAA), a monomer combination that is commonly used to prepare chemically cross-linking hydrogels, can generate self-healable hydrogels with mechanically resilient and adhesive properties through a facile one-step free radical copolymerization. The hydrogen bonds break and reform, providing an effective energy dissipation mechanism and synergic mechanical reinforcement. The physical properties can be simply tuned by OEGMA/MAA ratio control and reversible pH adjustment. Furthermore, the hydrogel can serve as a robust template for biomineralization to produce hydrogel composite that facilitate cell attachment and proliferations. This work is synthetically simple and dramatically increases the choice of amendable and adhesive hydrogels for industrial and biomedical applications.

This review highlights the most recent progress in gelation strategies of biomedical supramolecular and dynamic covalent crosslinking hydrogels and their applications for enhancing cell retention and cartilage regeneration.

Self‐healable hydrogels are promising soft materials with great potential in biomedical applications due to their autonomous self‐repairing capability. Although many attempts are made to develop new hydrogels with good self‐healing performance, to integrate this characteristic along with other responsive multifunctions into one hydrogel still remains difficult. Here, a self‐healable hybrid supramolecular hydrogel (HSH) with tunable bioadhesive and stimuli‐responsive properties is reported. The strategy is imparting graphene oxide (GO) nanosheets and quadruple hydrogen bonding ureido‐pyrimidinone (UPy) moieties into a thermoresponsive poly(N‐isopropylacrylamide) (PNIPAM) polymer matrix. The obtained GO–HSH hydrogel shows rapid self‐healing behavior and good adhesion to various surfaces from synthetic materials to biological tissue. In addition, doxorubicin hydrochloride (DOX) release profiles reveal the dual thermo‐ and pH‐responsiveness of the GO–HSH hydrogel. The DOX‐loaded hydrogel can further directly adhere to titanium substrate, and the released DOX from this thin hydrogel coating remains biologically active and has high capability to kill tumor cells.

Supramolecular dynamic hydrogels with quadruple hydrogen bonds and thermo-triggered hydrophobic interactions demonstrate a promising capability of modulating transplanted cell retention.