In situ forming injectable GelMA hydrogels enable for MSC delivery and vascularized sweat gland regeneration

Enhejirigala, ^1,2,3,, Bin Yao⁴, Zhao li^2,3, Yijie Zhang³, Chao Zhang ⁵,Sha Huang ^2,3*, Xiaobing Fu^2,3

¹Institute of Basic Medical Research, Inner Mongolia Medical University, Hohhot ⁰¹⁰¹¹⁰, Inner Mongolia, China.
²Research Center for Tissue Repair and Regeneration, Medical Innovation Research Department and the Fourth Medical Center, Chinese PLA General Hospital and PLA Medical College, Beijing ¹⁰⁰⁰⁴⁸, China.
³PLA Key Laboratory of Tissue Repair and Regenerative Medicine and Beijing Key Research Laboratory of Skin Injury, Repair and Regeneration, Chinese PLA General Hospital and PLA Medical College, Beijing ¹⁰⁰⁸⁵³, China.
⁴Academy of Medical Engineering and Translational Medicine, Tianjin University, ³⁰⁰⁰⁷², P. R. China.
⁵School of Medicine, Nankai University, Tianjin ³⁰⁰⁰⁷¹, China.

Objective: Sweat glands are critical for thermoregulation in mammals, while they have low regenerative potential in response to injury, which needs exogenous mesenchymal stem cells (MSC) for repair. Due to the challenges associated with stem cell delivery, a local and minimally invasive approach with high efficiency and improved cell viability is desired. Methacrylated gelatin (GelMA), a UV-photocrosslinkable hydrogel, is widely used as the cell delivery vehicle for its unique biofunctionality. The present study aims to demonstrate the feasibility of delivery MSC and induction components (mouse plantar dermis, PD) inside GelMA for sweat gland regeneration.
Methods: The GelMA hydrogel is characterized for pore structure, mechanical strength, viscosity, and degradation as well as in situ forming capability required to subcutaneously inject into mice is also determined. MSC viability and function within the GelMA hydrogel is characterized in vitro and the regenerative efficacy is demonstrated in vivo using a mouse skin wound model.
Results: In vivo and in vitro results demonstrated that the GelMA hydrogels exhibited excellent physical properties and efficient biocompatibility. GelMA hydrogels showed stronger activity on MSC compared to the MSC control group. The GelMA /MSC/PD group induced the angiogenesis and improved the sweat gland differentiation potential of MSC. Finally, thus hydrogel promoted in situ vascularized sweat gland regeneration.
Conclusion: We developed a fast and efficient in situ inductive niche based on photopolymerized hydrogels for sweat gland immersion.

Keywords: Cell immersion; GelMA; In situ niche; Sweat gland; Vascularization.

Ethical statement: -

Funding statement: -