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Abstract Dynamic covalent chemistry (DCC) crosslinks can form hydrogels with tunable mechanical properties permissive to injectability and self‐healing. However, not all hydrogels with transient crosslinks are easily extrudable. For this reason, two additional design parameters must be considered when formulating DCC‐crosslinked hydrogels: 1) degree of functionalization (DoF) and 2) polymer molecular weight (MW). To investigate these parameters, hydrogels comprised of two recombinant biopolymers: 1) a hyaluronic acid (HA) modified with benzaldehyde and 2) an elastin‐like protein (ELP) modified with hydrazine (ELP‐HYD), are formulated. Several hydrogel families are synthesized with distinct HA MW and DoF while keeping the ELP‐HYD component constant. The resulting hydrogels have a range of stiffnesses,G′ ≈ 10–1000 Pa, and extrudability, which is attributed to the combined effects of DCC crosslinks and polymer entanglements. In general, lower MW formulations require lower forces for injectability, regardless of stiffness. Higher DoF formulations exhibit more rapid self‐healing. Gel extrusion through a cannula (2 m length, 0.25 mm diameter) demonstrates the potential for minimally invasive delivery for future biomedical applications. In summary, this work highlights additional parameters that influence the injectability and network formation of DCC‐crosslinked hydrogels and aims to guide future design of injectable hydrogels.
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Fibro‐Gel: An All‐Aqueous Hydrogel Consisting of Microfibers with Tunable Release Profile and its Application in Wound Healing
Abstract Injectable hydrogels are valuable tools in tissue engineering and regenerative medicine due to their unique advantages of injectability with minimal invasiveness and usability for irregularly shaped sites. However, it remains challenging to achieve scalable manufacturing together with matching physicochemical properties and on‐demand drug release for a high level of control over biophysical and biomedical cues to direct endogenous cells. Here, the use of an injectable fibro‐gel is demonstrated, a water‐filled network of entangled hydrogel microfibers, whose physicochemical properties and drug release profiles can be tailored to overcome these shortcomings. This fibro‐gel exhibits favorable in vitro biocompatibility and the capability to aid vascularization. The potential use of the fibro‐gel for advancing tissue regeneration is explored with a mice excision skin model. Preliminary in vivo tests indicate that the fibro‐gel promotes wound healing and new healthy tissue regeneration at a faster rate than a commercial gel. Moreover, it is demonstrated that the release of distinct drugs at different rates can further accelerate wound healing with higher efficiency, by using a two‐layer fibro‐gel model. The combination of injectability and tailorable properties of this fibro‐gel offers a promising approach in biomedical fields such as therapeutic delivery, medical dressings, and 3D tissue scaffolds for tissue engineering.
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- Award ID(s):
- 2011750
- PAR ID:
- 10508976
- Publisher / Repository:
- Advanced Materials
- Date Published:
- Journal Name:
- Advanced Materials
- Volume:
- 35
- Issue:
- 19
- ISSN:
- 0935-9648
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.1002/adma.202211637
