Inha University researchers develop self-healing hydrogel for cultured marbled meat

A research team from Inha University in Incheon, South Korea, led by Dongyeop X. Oh, has unveiled a self-healing hydrogel technology that could improve the production of marbled cultured meat, eliminating the need for external adhesives or mechanical processing. The innovation, recently published in the American Chemical Society journal, demonstrates how a combination of boronic acid-conjugated chitosan and poly(vinyl alcohol) can enable precise layering of fat and muscle tissues, replicating the marbling structure of conventional meat products such as pork belly and steak.

The group, which includes Lam Tan Hao, Seunghyeon Lee, Dong Soo Hwang, Hyeonyeol Jeon, Jeyoung Park, and Hyo Jeong Kim, reports that their hydrogel scaffolds support strong yet reversible bonding at neutral pH. This enables cultured fat and muscle cells to adhere and differentiate effectively, overcoming the challenges posed by coculturing or insufficient adhesion between monocultures.

“Unlike conventional hydrogels that require nonphysiological conditions for strong reversible bonding, our system achieves robust bonding at neutral pH through nucleophilic groups in chitosan,” the researchers write. They explain that these groups promote the formation of boronic acid–diol bonds, providing structural integrity while allowing dynamic rearrangement critical for tissue culture.

One of the primary hurdles in cultured meat development has been recreating marbling patterns that mimic the look and mouthfeel of traditional meat. In current models, fat and muscle cells either must be grown together – a process fraught with difficulty due to their differing requirements – or are assembled post-growth, often requiring meat glues or binding equipment. The new hydrogel resolves both issues by self-assembling via dual reversible networks of boronic acid–diol and hydrogen bonds, offering mechanical tunability and biocompatibility.

Mechanical testing revealed that the hydrogels could be engineered to have compressive strengths of up to 2.41 megapascals and Young’s moduli ranging from 59.6 to 440 kilopascals, sufficient for supporting various tissue types. Moreover, the materials recovered well from repeated compression and demonstrated fatigue resistance over 100 loading-unloading cycles, an important factor given the physical stresses involved in tissue growth.

Using this system, the team successfully cultured 3T3-L1 preadipocytes and C2C12 myoblasts – two well-known mouse-derived cell lines – within hydrogels tuned to their specific mechanical needs. Softer variants of the hydrogel encouraged fat cell proliferation and differentiation, while stiffer scaffolds were better suited for muscle tissue. The team also validated their approach using bovine primary muscle cells, a step closer to commercially relevant cultured beef.

After 28 days of cell growth and differentiation, the researchers created centimeter-scale cultured meat prototypes by assembling the matured fat and muscle tissues. Muscle cells stained red with food-grade carmine contrasted against unstained fat cells, allowing visual confirmation of marbling. The structures included stacked and edge-to-edge arrangements, closely mimicking the architecture of naturally marbled meat.

To test its culinary potential, the assembled meat prototype was pan-fried in sunflower oil at 150°C for four minutes. The cooked sample retained its structural integrity and resembled the texture of bacon, a processed meat product typically lacking vascular structure.

The team analyzed the nutritional content of the prototype, which consisted of 64.5% muscle and 35.5% fat by weight. It contained approximately 10% protein and 19% fat, of which nearly 70% was unsaturated – a proportion in line with that found in conventional meat. The elemental composition also matched values for natural muscle and fat tissues, confirming that the hydrogel supported authentic tissue development.

Concerns about boron content – due to the use of boronic acid – were addressed through both quantitative analysis and regulatory context. The total boron content remained below 0.07% by weight, corresponding to under 0.4% boric acid equivalent, which falls within food safety limits. Furthermore, most boron was covalently bonded to chitosan, making it unlikely to pose a risk under normal consumption.

Notably, the team demonstrated that soaking the cultured tissue in a 5% glucose solution further reduced boron content while retaining structural integrity. The glucose triggers hydrogel disintegration by competing for boronic acid binding, providing a potential post-processing method for minimizing residual scaffold material.

The innovation shows promise not only for creating realistic cultured meat but also for addressing technical bottlenecks in scale-up and production. “To the best of our knowledge, this is the first report on the application of self-healing scaffolding technology for the fabrication of marbled cultured meat,” the researchers note.

The hydrogel platform’s compatibility with a range of tissue types, mechanical adaptability, and responsiveness to physiological conditions suggest that it could streamline manufacturing workflows and offer more control over final product attributes such as texture and nutrient profile. By bypassing the need for meat glue and complex post-assembly machinery, this self-healing scaffold could be an important step toward economically viable cultured meat products.