Tag Archives: adhesive

A bioinspired hydrogel patch with controllable adhesion properties for enhanced soft tissue repair

The paper’s graphical abstract presents some intriguing visuals,

Caption: Schematic representation of the A/B-sides multi-biological functional hydrogel patch. Credit: Wenle Chen from Shenzhen Second People’s Hospital, First Affiliated Hospital of Shenzhen University and Yu Wang from Wenzhou Institute, University of Chinese Academy of Sciences.

Let’s find out what those visuals were intended to convey, from an August 6, 2025 Songshan Lake Materials Laboratory (SLAB) press release on EurekAlert.org announced a bioinspired hydrogel patch,

A research team from Shenzhen University, University of Chinese Academy of Sciences and Hong Kong Polytechnic University has developed an innovative, bioinspired hydrogel patch with controllable adhesion properties to enhance soft tissue repair and prevent adhesions. Inspired by octopus suction cups and the eyeball surfaces, this patch features a dual-sided design: one side offers adjustable, revocable adhesion, while the other provides anti-adhesive functions. In vivo [animal] experiments demonstrate its effectiveness in reducing inflammation, promoting tissue healing, and allowing repositioning during surgical procedures, marking a significant advancement in biomedical materials.

Tissue repair required in scenarios such as trauma, post-operative of tumors is a common challenge for human healthcare. Soft tissue injuries and surgical wounds often face challenges such as excessive tissue adhesion, which can complicate healing and cause secondary complications. Traditional patches and sutures either lack adequate adhesion or induce unwanted tissue sticking, leading to inflammation and hindered recovery. There is an urgent need for biomaterials that can intelligently balance strong tissue integration with the ability to detach or reposition easily, matching the dynamic environment of internal tissues.

In this context, hydrogel patches, owing to their exceptional biocompatibility and potential adhesive properties, are expected to become ideal materials for soft tissue repair. These materials can gradually degrade, naturally integrate with human tissues, and easily incorporate drugs or growth factors to promote angiogenesis, thereby enhancing the speed and quality of tissue healing. In general, the common hydrogel patches can be divided into adhesive ones and anti-adhesive ones. Adhesive patches can form rapid and strong covalent bonds with moist tissue to promote tissue regeneration, whose further applications are limited by excessive tissue adhesion. While anti-adhesive patches can address the tissue adhesion problem by hydrophobic surface modification or coarse structure design, they are difficult to fit the wounds tightly for treatment. Hence, it is necessitating to design an anisotropic patch combining the merits of promoting tissue regeneration and anti-adhesive function.

The Solution: Drawing inspiration from nature, interdisciplinary research team engineered a novel hydrogel patch that mimics natural mechanisms using suction cup-like structures for physical, reversible adhesion and covalent bonds for permanent fixation. The patch’s adhesive side uses microstructures that generate negative pressure for temporary adhesion, allowing surgeons to adjust its position during surgery, once aligned, chemical reactions secure a firm, covalent attachment. The other side is made of highly hydrated, anti-adhesive materials to prevent surrounding tissue from sticking undesirably. Additionally, the patch absorbs positively charged inflammatory factors and provides sustained drug release, further aiding in inflammation reduction and tissue regeneration.

The bioinspired system features a multi-functional, dual-sided hydrogel patch composed of polyacrylic acid-NHS for the adhesive surface, and polyvinyl alcohol (PVA) combined with polyethylene glycol diacrylate (PEGDA) for the anti-adhesive barrier. Its porous network not only enables physical and chemical adhesion but also captures inflammatory cytokines, fostering a more favourable healing environment. In vivo tests in animal models confirmed the patch’s strong, controllable adhesion, its ability to prevent unwanted tissue adhesion, and its capacity to promote faster, healthier tissue repair.

The Future: This innovative hydrogel patch represents a significant step forward in the field of soft tissue repair. It combines the benefits of promoting tissue regeneration and preventing adhesion into one device. Future research will focus on optimizing the patch’s properties for specific clinical applications, such as abdominal wall defect repair and other dynamic wound management scenarios. The development of advanced manufacturing technologies like 3D bioprinting could also enable the customization of patch geometry for specific anatomical structures. Additionally, the exploration of environmentally adaptive intelligent components could lead to a more precise control of adhesion and drug release that aligns with the tissue regeneration process.

The Impact: This hydrogel patch offers a new paradigm for soft tissue repair with its “revocable” adhesion properties. It has the potential to significantly reduce clinical adhesion scores, effectively reduce inflammation, promote wound healing, and enhance collagen deposition. The successful integration of controllable adhesion and anti-adhesion functions in one patch could revolutionize the way we approach soft tissue repair and adhesion prevention in clinical settings.

Here’s a link to and a citation for the paper,

Bioinspired hydrogel patch with controllable adhesion for soft tissue repair by Wenle Chen, Wenzhao Li, Puxiang Lai, Jian Cai, Lingyu Sun, Yu Wang. Materials Futures, Volume 4, Number 3 Published Date: July 20, 2025 DOI: 10.1088/2752-5724/adec0a © 2025 The Author(s). Published by IOP Publishing Ltd on behalf of the Songshan Lake Materials Laboratory

This paper is open access.

Ouchies no more! Not from bandages, anyway.

An adhesive that US and Chinese scientists have developed shows great promise not just for bandages but wearable robotics too. From a December 14, 2018 news item on Nanowerk,

Researchers from the Harvard John A. Paulson School of Engineering and Applied Sciences (SEAS) and Xi’an Jiaotong University in China have developed a new type of adhesive that can strongly adhere wet materials — such as hydrogel and living tissue — and be easily detached with a specific frequency of light.

The adhesives could be used to attach and painlessly detach wound dressings, transdermal drug delivery devices, and wearable robotics.

A December 18, 2018 SEAS news release by Leah Burrows (also on EurekAlert but published Dec. 14, 2018), which originated the news item, delves further,

“Strong adhesion usually requires covalent bonds, physical interactions, or a combination of both,” said Yang Gao, first author of the paper and researcher at Xi’an Jiaotong University. “Adhesion through covalent bonds is hard to remove and adhesion through physical interactions usually requires solvents, which can be time-consuming and environmentally harmful. Our method of using light to trigger detachment is non-invasive and painless.”

The adhesive uses an aqueous solution of polymer chains spread between two, non-sticky materials — like jam between two slices of bread. On their own, the two materials adhere poorly together but the polymer chains act as a molecular suture, stitching the two materials together by forming a network with the two preexisting polymer networks. This process is known as topological entanglement.

When exposed to ultra-violet light, the network of stitches dissolves, separating the two materials.

The researchers, led by Zhigang Suo, the Allen E. and Marilyn M. Puckett Professor of Mechanics and Materials at SEAS, tested adhesion and detachment on a range of materials, sticking together hydrogels; hydrogels and organic tissue; elastomers; hydrogels and elastomers; and hydrogels and inorganic solids.

“Our strategy works across a range of materials and may enable broad applications,” said Kangling Wu, co-lead author and researcher at Xi’an Jiaotong University in China.
While the researchers focused on using UV light to trigger detachment, their work suggests the possibility that the stitching polymer could detach with near-infrared light, a feature which could be applied to a range of new medical procedures.

“In nature, wet materials don’t like to adhere together,” said Suo. “We have discovered a general approach to overcome this challenge. Our molecular sutures can strongly adhere wet materials together. Furthermore, the strong adhesion can be made permanent, transient, or detachable on demand, in response to a cue. So, as we see it, nature is full of loopholes, waiting to be stitched.”

Here’s a link to and  a citation for the paper,

Photodetachable Adhesion by Yang Gao, Kangling Wu, Zhigang Suo. https://doi.org/10.1002/adma.201806948 First published: 14 December 2018

This paper is behind a paywall.