Using bioprinting and spheroid culture to create a skin model with sweat glands and hair follicles

Yijie Zhang; Enhejirigala; Bin Yao; Zhao Li; Wei Song; Jianjun Li; Dongzhen Zhu; Yuzhen Wang; Xianlan Duan; Xingyu Yuan; Sha Huang; Xiaobing Fu

doi:10.1093/burnst/tkab013

Using bioprinting and spheroid culture to create a skin model with sweat glands and hair follicles

Burns Trauma. 2021 May 4:9:tkab013. doi: 10.1093/burnst/tkab013. eCollection 2021.

Authors

Yijie Zhang^{1

2}, Enhejirigala^{1

2

3

4}, Bin Yao^{1

2

5}, Zhao Li¹, Wei Song^{1

2}, Jianjun Li^{1

2

6}, Dongzhen Zhu^{1

2}, Yuzhen Wang^{1

2

7}, Xianlan Duan^{1

2

8}, Xingyu Yuan^{1

2

8}, Sha Huang¹, Xiaobing Fu^{1

2

9}

Affiliations

¹ Research 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.
² PLA 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.
³ College of Graduate, Tianjin Medical University, Tianjin 300070, China.
⁴ Institute of Basic Medical Research, Inner Mongolia Medical University, Hohhot 010110, Inner Mongolia, China.
⁵ The Shenzhen Key Laboratory of Health Sciences and Technology, Graduate School at Shenzhen, Tsinghua University, Shenzhen 518055, Guangdong, China.
⁶ Department of General Surgery, the Sixth Medical Center, Chinese PLA General Hospital, Beijing 100048, China.
⁷ Department of Burn and Plastic Surgery, Air Force Hospital of Chinese PLA Central Theater Command, Datong 037000, Shanxi, China.
⁸ School of Medicine, Nankai University, Tianjin 300071, China.
⁹ Research Unit of Trauma Care, Tissue Repair and Regeneration, Chinese Academy of Medical Sciences, 2019RU051, Beijing 100048, China.

Abstract

Background: Sweat glands (SGs) and hair follicles (HFs) are two important cutaneous appendages that play crucial roles in homeostatic maintenance and thermoregulation, and their interaction is involved in wound healing. SGs can be regenerated from mesenchymal stem cell-laden 3D bioprinted scaffolds, based on our previous studies, whereas regeneration of HFs could not be achieved in the same model. Due to the lack of an in vitro model, the underlying molecular mechanism of the interaction between SGs and HFs in regeneration could not be fully understood. The purpose of the present study was to establish an in vitro model of skin constructs with SGs and HFs and explore the interaction between these two appendages in regeneration.

Methods: To investigate the interaction effects between SGs and HFs during their regeneration processes, a combined model was created by seeding HF spheroids on 3D printed SG scaffolds. The interaction between SG scaffolds and HF spheroids was detected using RNA expression and immunofluorescence staining. The effects of microenvironmental cues on SG and HF regeneration were analysed by altering seed cell types and plantar dermis homogenate in the scaffold.

Results: According to this model, we overcame the difficulties in simultaneously inducing SG and HF regeneration and explored the interaction effects between SG scaffolds and HF spheroids. Surprisingly, HF spheroids promoted both SG and HF differentiation in SG scaffolds, while SG scaffolds promoted SG differentiation but had little effect on HF potency in HF spheroids. Specifically, microenvironmental factors (plantar dermis homogenate) in SG scaffolds effectively promoted SG and HF genesis in HF spheroids, no matter what the seed cell type in SG scaffolds was, and the promotion effects were persistent.

Conclusions: Our approach elucidated a new model for SG and HF formation in vitro and provided an applicable platform to investigate the interaction between SGs and HFs in vitro. This platform might facilitate 3D skin constructs with multiple appendages and unveil the spatiotemporal molecular program of multiple appendage regeneration.

Keywords: 3D bioprinting; Hair follicle; Skin constructs; Skin regeneration; Spheroid culture; Sweat glands.