A tarsus construct of a novel branched polyethylene with good elasticity for eyelid reconstruction in vivo

Abstract

Branched polyethylene (B-PE) elastomer was investigated for its potential medical application as a tarsus construct. The in vitro results showed that the B-PE and processed B-PE films or scaffolds did not exhibit noticeable cytotoxicity to the NIH3T3 fibroblasts and human vascular endothelial cells (ECs). The B-PE scaffolds with a pore size of 280–480 µm were prepared by using a gelatin porogen-leaching method. The porous scaffolds implanted subcutaneously in rats exhibited mild inflammatory response, collagen deposition and fast fibrovascularization, suggesting their good biocompatibility. Quantitative real-time PCR analysis showed low expression of pro-inflammatory genes and up-regulated expressions of collagen deposition and vascularization-related genes, validating the results of historical evaluation in a molecular level. The B-PE scaffolds and Medpor controls were transplanted in rabbits with eyelid defects. The B-PE scaffolds exhibited a similar elastic modulus and provided desirable repair effects with mild fibrous capsulation, less eyelid deformities, and were well integrated with the fibrovascular tissue compared with the Medpor controls.

Polymers and Biomaterials for Posterior Lamella of the Eyelid and the Lacrimal System

“…These scaffolds showcased approximately 90% porosity, appropriate degradation rates, and good biocompatibility, influencing cellular behaviors like proliferation and distribution. When tested in a rabbit model, the scaffolds encouraged re-epithelization, inferring its potential as a substitute for tarso-conjunctival repair [90].…”

“…Recent studies have also explored the use of synthetic polymers, including porous polyethylene (PE) [90,96], poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBHHx) [97], poly(lactic-co-glycolic) acid (PLGA) [98][99][100], and PCL [101] for tarsal plate reconstruction. Among these, only high-density porous PE (Medpor ® ) has been clinically leveraged as an eyelid spacer to address lower eyelid retraction.…”

Biomaterials and tissue engineering strategies for posterior lamellar eyelid reconstruction: Replacement or regeneration?

“…Therefore, various modified PCL scaffolds have attracted intensive attention in conjunctival equivalent engineering due to their great potential for clinical translation. 116 Additionally, synthetic polymers, such as porous polyethylene (PE), 13,104,123 poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBHHx), 124 poly(propylene fumarate) (PPF), 125,126 poly(lactic-coglycolic) acid (PLGA), 18 and PCL, 16 have also been used in tarsal plate reconstruction in recent studies. Among them, only porous high-density PE (Medpor ® ) has been used as an eyelid spacer for treating lower eyelid retraction in clinical practice.…”

“…Ideally, bioengineered posterior lamellar substitutes should restore key structures and functions of the eyelid without additional donor‐site morbidities or postoperative complications. To date, many innovative native tissue grafts, 10 , 11 biomaterials, 12 , 13 and bioengineered tissues 14 , 15 have been proposed as posterior lamellar substitutes, some of which have been clinically used for eyelid reconstruction and have yielded promising preliminary results. 11 , 14 , 15 The bioengineering of posterior lamellar substitutes can be categorized into two distinct approaches: (1) acellular approaches, in which natural or synthetic acellular biomaterials are transplanted into defect areas to act as bioscaffolds for guiding tissue regeneration in vivo by leveraging endogenous cells and microenvironments (Figure 4a ); and (2) cellular approaches, in which bioscaffolds are precellularized in vitro to mimic specific functions of the target tissue and then transplanted to promote tissue regeneration (Figure 4b ).…”

Posterior lamella substitutes in full-thickness eyelid reconstruction: a narrative review

“…It is divided into anterior and posterior lamellae by the grey line. The anterior lamella includes the eyelid skin, subcutaneous tissue, and orbicularis oculi muscle, while the posterior consists of the tarsal plate and conjunctiva (2,3). The intact eyelid structure and function are responsible for the stable ocular structure and visual function and necessary for the composition of eye expression.…”