Multifunctional hydrogels

Minimally invasive insertion requires small sizes of scaffolds. Here, the authors inspired by the shrinking of puffed food in humid air develop a hydrogel scaffold posttreatment where lyophilization and dampening result in scaffold shrinkage of 90% in volume with post-surgery size recovery and lower foreign body response.

NCOMMS−24−25010C Penetrating orocutaneous or oropharyngeal fistulas (POFs) are hard to treat, due to tissue deficiency, saliva contamination, and dynamic oral conditions. Here, the authors report a Janus hydrogel adhesive that prompts POF wound healing by seamless plugging of the penetrating wound, protecting it from mechanical stimuli and bacterial infection, and creating a pro-healing microenvironment.

Existing biodegradable materials lack long-term therapeutical effect because of their gradual degradation. Here, the authors develop a degradable material with continuous ROS modulation, which rapidly eliminates bacteria and promotes bone regeneration in infected cranial defects.

During biosignal recording, breathing creates noise. Here, the authors propose a hydrogel with selective damping and asymmetric adhesion that reduces breathing noise and enhances signal stability.

Electroceuticals could treat refractory diseases by the selective modulation of peripheral nerves but their utility is hindered by the small sizes and the delicate nature of the nerves. Here, the authors address these issues by developing an injectable, stable, and conductive hydrogel that allows a safer and more effective treatment during chronic neuromodulation of delicate peripheral nerves.

Drug delivery platforms are needed for combatting osteosarcoma, which accounts for a large proportion of malignant bone tumors. This Review highlights recent progress in drug delivery methods, including systemic nanoparticle-based drug delivery and local strategies such as nanoparticles, hydrogels, and scaffolds, while addressing ongoing challenges and future research needs.

Type II collagen, a key component of cartilaginous tissue, provides mechanical strength, supports cell growth, and regulates cellular processes. This Review covers the applications and advancements of type II collagen scaffolds in tissue engineering, focusing on hyaline cartilage and fibrocartilage.

Enzyme-based wearable biosensors offer a unique approach for biomarker detection. This Review discusses recent progress in enzymatic biosensors and biofuel cells, where biofuels self-power the device while enzymes concurrently work for biomarker detection.

Generating 3D bone cell networks in vitro that mimic the dynamic process during early bone formation is vital for creating in vitro models of bone development for disease modeling and drug testing, but remains challenging. Herein, the authors report a synthetic biodegradable microporous hydrogel for in vitro generation of functional human bone cell networks in 3D and microfluidic integration.

Suture repair is the current clinical treatment for meniscus tears, but inaccessible tears in company with re-tears susceptibility remain unresolved. Here the authors address these issues by developing a meniscus adhesive-based strategy for the seamless and dense reconstruction of torn meniscus.

Myocardial infarction can lead to malignant arrhythmia and myocardial remodeling. Here, the authors report a microchanneled hydrogel suture for two-way signal communication, pumping drugs on demand, and cardiac repair.

Surgery is a primary therapeutic modality for treating melanoma, but it is challenging to tackle tumor recurrence/metastasis and postsurgical wounds. Here the authors report a sprayable hydrogel capable of long-lasting and controllable oxygen supply for preventing tumor recurrence/metastasis and simultaneously promoting wound healing during the postsurgical treatment of melanoma.

Developing mechanically robust hydrogels with high lubricity is challenging but desirable. Here, the authors report the development of a layered hydrogel with a robust and wrinkled lubrication layer, and pores for storing lubricants, for sustained lubricity.

Hydrogel-based machines have potential in a range of applications, but it can be challenging to prepare multimaterial devices with complex structures. Here, the authors report the development of a multimaterial cryogenic printing technique that can be used to prepare three-dimensional structures with geometries such as overhanging, thin-walled and hollow.

Hydrogel-based flexible sensors have potential in a number of fields, but mechanical properties can be compromised as a result of water evaporation. Here, the authors report a method for limiting of water loss by addition of a lipid-based coating to the surface of the hydrogel.

Hydrogels with room temperature phosphorescence have potential in a number of applications, but mechanical properties can limit the potential. Here, the authors report a wood-based hydrogel with room temperature phosphorescence, by polymerization of acrylamide with delignified wood.

Materials are needed that can form stable interfaces with neurons, and soft materials are the most promising for this. Here, the advantages and challenges associated with neural interfaces using hydrogels, particularly conductive hydrogels, are discussed.

Sustainable production of materials is important as global environmental issues increase. Here, orange peels are incorporated as the main material in a hydrogel to prepare a flexible, natural, biocompatible, and sustainably produced electronic skin.