Glioblastoma (GBM) is the most malignant type of primary intracranial tumor with a median overall survival of only 14 months, a very poor prognosis and a recurrence rate of 90%. It is difficult to reflect the complex structure and function of the GBM microenvironment in vivo using traditional in vitro models. GBM-on-a-chip platforms can integrate biological or chemical functional units of a tumor into a chip, mimicking in vivo functions of GBM cells. This technology has shown great potential for applications in personalized precision medicine and GBM immunotherapy. In recent years, there have been efforts to construct GBM-on-a-chip models based on microfluidics and bioprinting. A number of research teams have begun to use GBM-on-a-chip models for the investigation of GBM progression mechanisms, drug candidates, and therapeutic approaches. This review first briefly discusses the use of microfluidics and bioprinting technologies for GBM-on-a-chip construction. Second, we classify non-surgical treatments for GBM in pre-clinical research into three categories (chemotherapy, immunotherapy and other therapies) and focus on the use of GBM-on-a-chip in research for each category. Last, we demonstrate that organ-on-a-chip technology in therapeutic field is still in its initial stage and provide future perspectives for research directions in the field.

The long-term stable monitoring of brain signals, including electroencephalogram (EEG), electrocorticogram (ECoG) and local field potential (LFP), is of great significance for the fundamental research in brain science, artificial intelligence and the diagnosis and treatment of brain-related disorders. Therefore, both non-invasive and invasive brain-machine interfaces based on different materials and structures have been widely studied due to their unique performance. Among these materials, hydrogels have emerged as a promising interface material for brain signal collection systems due to their similar mechanical properties to biological tissues, excellent biocompatibility, strong self-adhesive properties, and exceptional ionic conductive characteristics. This review aims to provide an overview on the recent progress of hydrogel-based brain interfaces in the recording of brain signals with non-invasive and invasive methods. It is expected that this paper will serve as a valuable summary and reference for future research in the hydrogel-based brain interface.

Hydrogels with micro/nano‐structures precisely prepared by femtosecond‐laser processing technology are biomaterials that mimic the natural extracellular matrix and can achieve the precise regulation of biological properties, such as cell behavior and structural–mechanical properties. They also play a crucial role in biomedical fields such as regenerative medicine, bionanostructural construction, drug transport, and particle manipulation. This study summarizes the central role of the nonlinear absorption property of femtosecond lasers in the preparation of hydrogel micro/nano‐structures. Based on the electron‐dynamics model and electron‐density flood theory, the two main processing types of the femtosecond laser‐processed hydrogel, additive and subtractive manufacturing, are discussed in depth. The modification mechanisms such as the photon–electron energy‐field conversion, multiphoton absorption effect, and bubble‐driven bio‐link molding are analyzed. Additionally, the stimulus‐response diversification and functional biomimicry properties of the structural hydrogels under the influences of different laser action modes and hydrogel composition ratios are investigated for their biomedical applications, such as microactuators, drug delivery, microscaffolds, and the in vitro simulation of vascular networks. On this basis, the advantages and limitations of the current technology are summarized and a reasonable prediction for future research on the law of action of the femtosecond‐laser preparation of hydrogel micro/nano‐structures is made.

Hydrogels have indeed achieved significant advancements, yet their clinical translation has been hampered by their inherent limitations in wet adhesion properties. Furthermore, the design of adhesive hydrogels that can resist postoperative adhesions remains an intricate challenge. In this study, we introduce a Janus hydrogel (JGP) that offers a novel approach to address these challenges. The JGP hydrogel has two asymmetrical sides, consisting of an adhesion layer (AL) and an anti-adhesion layer (AAL). Specifically, the AL incorporates three key components: N-[tris(hydroxymethyl)methyl]acrylamide (THMA), acrylic acid (AAc), and the acrylic acid N-hydroxysuccinimide ester (AAc-NHS). By drying the AL, it has a rapid water absorption capability. The abundance of hydroxyl and carboxyl groups in the AL enables the formation of robust hydrogen bonds with tissues, thereby achieving superior adhesive properties. Additionally, the synergistic effect of THMA's tridentate hydrogen bonding and the covalent bonding formed by AAc-NHS with tissue ensures long-lasting wet adhesion. To realize the anti-adhesion function, one side of the AL was immersed in a solution of [2-(methacryloyloxy)ethyl]dimethyl-(3-sulfopropyl)ammonium hydroxide (SBMA), which undergoes crosslinking to form the AAL. A comprehensive series of tests have confirmed that the JGP hydrogel exhibits exceptional mechanical properties, efficient and enduring adhesion, excellent biocompatibility, and degradability. Moreover, it possesses remarkable hemostatic properties and robust anti-abdominal adhesion characteristics.