Reconstruction of posterior lamellar eyelids remains challenging due to their delicate structure, highly specialized function, and cosmetic concerns. Current clinically available techniques for posterior lamellar reconstruction mainly focus on reconstructing the contour of the eyelids. However, the posterior lamella not only provides structural support for the eyelid but also offers a smooth mucosal surface to facilitate globe movement and secrete lipids to maintain ocular surface homeostasis. Bioengineered posterior lamellar substitutes developed via acellular or cellular approaches have shown promise as alternatives to current therapies and encouraging outcomes in animal studies and clinical conditions. Here, we provide a brief reference on the current application of autografts, biomaterials, and tissue-engineered substitutes for posterior lamellar eyelid reconstruction. We also shed light on future challenges and directions for eyelid regeneration strategies and offer perspectives on transitioning replacement strategies to regeneration strategies for eyelid reconstruction in the future.

[This corrects the article DOI: 10.3389/fbioe.2020.00219.].

Tarsal plate regeneration has always been a challenge in the treatment of eyelid defects. The commonly used clinical treatments such as hard palate mucosa grafts cannot achieve satisfactory repair effects. Tissue engineering has been considered as a promising technology. However, tarsal plate tissue engineering is difficult to achieve due to its complex structure and lipid secretion function. Three-dimensional (3D) printing technology has played a revolutionary role in tissue engineering because it can fabricate complex scaffolds through computer aided design (CAD). In this study, it was novel in applying 3D printing technology to the fabrication of tarsal plate scaffolds using poly-caprolactone (PCL). The decellularized matrix of adipose-derived mesenchymal stromal cells (DMA) was coated on the surface of the scaffold, and its biofunction was further studied. Immortalized human SZ95 sebocytes were seeded on the scaffolds so that neutral lipids were secreted for replacing meibocytes. In vitro experiments revealed excellent biocompatibility of DMA-PCL scaffolds with sebocytes. In vivo experiments revealed excellent sebocytes proliferation on the DMA-PCL scaffolds. Meanwhile, sebocytes seeded on the scaffolds secreted abundant neutral lipid in vitro and in vivo. In conclusion, a 3D-printed PCL scaffold modified with DMA was found to be a promising substitute for tarsal plate tissue engineering.

Transforming growth factor alpha (TGFα) belongs to the epidermal growth factor (EGF) family and is known to play an important role during eyelid morphogenesis. In this study, we showed that ectopic expression of TGFα in the stroma of Kera-rtTA/tet-O-TGFα bitransgenic mice results in precocious eye opening, abnormal morphogenesis of the meibomian gland, tendon and tarsal plate malformation and epithelium hyperplasia. TGFα did not change proliferation and differentiation of meibocytes, but promoted proliferation and inhibited differentiation of the tarsal plate tenocytes. These results suggest that proper formation of the tendon and tarsal plate in the mouse eyelid is required for normal morphogenesis of the meibomian gland.