A method for creating injectable hydrogels from microfiber suspensions for biomedical scaffolding and drug delivery

Background

Hydrogels are a class of water-swollen, cross-linked polymeric materials widely used in biomedical fields such as tissue engineering, drug delivery, and wound healing. Their ability to mimic the extracellular matrix and provide a hydrated environment makes them ideal scaffolds for supporting cell growth and delivering therapeutic agents. However, there is a growing demand for hydrogels that can be delivered minimally invasively—such as by injection—and that can encapsulate sensitive biological cargos like living cells or proteins without compromising their viability or function. This need is driven by the desire to create in situ-formed scaffolds for regenerative medicine and targeted therapies, where the hydrogel must form rapidly and safely within the body.

Current approaches to injectable hydrogel formation typically rely on chemical cross-linking reactions or reversible physical associations to achieve gelation. Chemical cross-linkers can introduce cytotoxicity, elicit immune responses, or interfere with the encapsulated biological materials, limiting their biocompatibility and clinical utility. Physical gelation methods, while gentler, often result in hydrogels with weak mechanical properties or require specific environmental triggers (such as temperature or pH changes) that may not be compatible with all therapeutic contexts. Additionally, many existing systems struggle to achieve rapid, robust gelation upon injection, and may not provide the mechanical stability or controlled release profiles needed for advanced biomedical applications. These limitations highlight the need for new strategies that enable safe, efficient, and versatile formation of injectable hydrogels suitable for sensitive biomedical uses.

Technology

This technology is an innovative injectable hydrogel system formed from suspensions of highly flexible, hydrophilic microfibers. These microfibers, which can be produced by microfluidic, wet spinning, or electrospinning techniques, are suspended at high concentrations in a liquid medium. When the suspension is extruded through a needle or nozzle, the mechanical stress induces irreversible entanglement of the fibers, resulting in the rapid formation of a stable, viscoelastic hydrogel network—without the need for chemical cross-linking agents. The process is gentle enough to encapsulate sensitive biological cargos such as living cells, therapeutic drugs, or nanoparticles within the fibers during production. The resulting hydrogel exhibits swelling behavior in aqueous environments and maintains mechanical properties suitable for use as scaffolds in tissue engineering, drug delivery matrices, wound dressings, and other biomedical applications.

What differentiates this technology is its purely mechanical gelation mechanism, which eliminates the need for chemical cross-linkers that can introduce toxicity or interfere with encapsulated biological materials. This flow-induced entanglement allows for immediate, in situ hydrogel formation upon injection, enabling minimally invasive procedures and precise placement of scaffolds or drug depots. The method is highly versatile, accommodating a range of fiber chemistries and production techniques, and allows for customizable cargo loading and release profiles. Its biocompatibility, simplicity, and adaptability make it a significant advancement over conventional hydrogels, particularly for applications requiring the safe delivery of living cells or sensitive therapeutics directly into the body.

Benefits

• Eliminates the need for chemical cross-linking, enhancing biocompatibility and reducing cytotoxicity risks.
• Enables immediate in situ hydrogel formation through injection, allowing minimally invasive delivery and scaffold creation.
• Supports encapsulation of diverse biological cargos, including living cells and therapeutic drugs, with customizable release profiles.
• Provides a mechanically stable, viscoelastic hydrogel suitable for tissue engineering and drug delivery applications.
• Offers versatility in microfiber production methods, accommodating various fabrication techniques.
• Exhibits swelling behavior in aqueous environments, maintaining functional hydrogel properties post-injection.
• Facilitates a gentle gelation process compatible with sensitive biological materials and therapeutics.

Applications

• Tissue engineering scaffolds
• Injectable drug delivery systems
• Wound dressings
• Surgical sealants and adhesives
• Nerve regeneration supports

Additional info

Concentrated suspensions of flexible hydrophilic microfibers undergo flow-induced mechanical entanglement during extrusion to form stable viscoelastic hydrogels. This purely mechanical gelation eliminates the need for chemical cross-linking agents, ensuring biocompatibility for sensitive cargos like living cells or therapeutics. The resulting injectable scaffolds exhibit significant swelling in aqueous environments and provide robust mechanical support for tissue engineering, wound dressings, and controlled drug delivery systems.