Introduction

A material that subtly binds our world together harbors a concealed dark side. Adhesives play a crucial role in our daily lives, as they are used in a wide range of applications, from basic household repairs to complex industrial manufacturing. The demand for adhesive products continues to rise rapidly yearly, with the industry growing by approximately one billion USD from 2023 to 2024 [1]. Annual global consumption is approximately 24.7 million metric tons [2]. However, many conventional adhesives are made from synthetic chemicals, raising severe environmental and health concerns due to their toxicity and non-biodegradable properties [3]. Besides their environmental impact and use in industrial structures, adhesives are crucial in the medical industry: electrocardiogram (ECG) sensor patches, transcutaneous electrical nerve stimulation (TENS) patches for chronic pain, negative pressure wound therapy (NPWT), and hormonal therapy. Medical patches, while convenient, still cause allergic reactions or skin irritations [4].

More specialized bandages, such as those used by patients with diabetes, are designed with specific purposes in mind. However, these plasters often have the drawback of peeling off prematurely - an issue that may seem minor but can create significant challenges for individuals managing diabetes. Currently, about 537 million people worldwide live with diabetes, leading to 1.5 million deaths annually, and these figures are projected to rise in the future [5][6]. For individuals with diabetes, effective management involves using advanced technologies such as insulin pumps and glucose sensors. While these devices have been shown to enhance quality of life significantly, they remain inaccessible to some.

Additionally, insulin pumps and glucose sensors rely on adhesive patches to remain attached to the body. Through surveys and interviews with diabetes patients, the Diabetes Association of Lithuania, and diabetes care specialists from Santaros Clinics, we discovered that adhesive patches often lead to dermatitis and allergic reactions. Moreover, many patients report that the patches fail to stay securely in place for extended periods, further complicating their use. Losing them can hurt patients financially and put their lives at risk. The individual value of each insulin pump or continuous glucose monitor can reach up to 5,000 USD (Fig. 1) [7][8]. The adhesive patches must remain securely in place to guarantee user safety.

Currently, there is no natural adhesive that minimizes the risk of allergies and skin irritations while offering strength up to three times greater than traditional super glue. Or is there?

This is precisely where our project, Synhesion, takes action. We boldly address this challenge by creating bio-based adhesives through genetically engineered bacteria. These adhesives surpass the strength of traditional superglue and significantly reduce allergy risks, offering a revolutionary solution.

Background

Bio-based adhesives present a compelling opportunity to revolutionize various industries, from medical devices to industrial manufacturing [9]. The adhering properties of bacterial adhesives, particularly those produced by Caulobacter crescentus and its close relative Hirschia baltica, are of significant interest due to their exceptional strength and biocompatibility [10][11].

C. crescentus is renowned for producing holdfast, a natural glue alternative among the strongest known biological adhesives [11]. This polysaccharide-based holdfast exhibits remarkable adhesive capabilities, making it an ideal candidate for eco-friendly glue applications [12]. However, the complex life cycle of C. crescentus makes it impractical using this organism for large-scale adhesive production and its applications in adhesives biomanufacturing.

Our solution

Synhesion targets a global challenge for 537 million diabetes patients by leveraging Escherichia coli to produce and refine adhesive polysaccharides from C. crescentus [6]. By transferring and activating the relevant holdfast-producing system (Fig. 2.) within E. coli, we could utilize its well-established culturing and genetic manipulation techniques to achieve scalable and efficient production.

The significance of this work lies in its potential to provide a sustainable, biodegradable alternative to synthetic adhesives, reducing environmental impact while enhancing biocompatibility in medical applications. By harnessing the natural adhesive properties of bacterial polysaccharides and tools of synthetic biology, Synhesion paves the way for significant advancements in day to day lives of diabetes patients all over the world.

Conclusion

Synhesion represents a significant step towards sustainable and versatile adhesive solutions. By exploiting the adhesive properties of bacterial glue and refining their production in E. coli, this project aims to deliver innovative solutions that address the escalating demand for eco-friendly and high-performance adhesives. Through our efforts, we strive to build a greener, more efficient future. Our team pursues to solve an immense problem for millions of people with a patch-sized solution.