Abstract
Purpose :
Acellular porcine cornea stroma (APCS) prepared using pancreatic phospholipase A2 was proven to be promising corneal scaffold. However, its dense ultrastructure provides insuffificient space that prevents the seeded cells from organizing into a functional tissue. The aim was to identify the porous APCS that is most suitable for the proliferation and migration of keratocytes. In addition, corneal transplantation was performed to evaluate the transparency of porous APCSs in vivo.
Methods :
In this report, freezing dry APCS (FD-APCS) biomaterials containing pores with different sizes were fabricated at different pre-freezing temperatures of -10, -80 or -198 C.
1. Analysis of pore size and pore size distribution
2. Assessment of porosity and permeability
3. Analysis of specifific surface area (SSA) of the scaffolds
4. Construction of corneal stroma in vitro
5. Cell proliferation within the FD-APCSs
6. Interlamellar keratoplasty in rabbits
Results :
The percentage of large pores (equivalent circle diameter ≥10 μm) was 93.55%, 69.36%, 35.79%, while the small pores (<10 μm) were account for 6.45%, 30.64%, 64.21%, respectively. Both porosity and specifific surface area increased in FD-APCS fabricated with decreased pre-freezing temperature, and they were dramatically higher than those in APCS. The three FD-APCS groups displayed higher permeability than APCS, and the -10 C FD-APCS possessed the highest permeability. The keratocytes seeded in the FD-APCS construct survived well in vitro, and maximal cell proliferation was observed in the -10 C FD-APCS. Following implantation, all of the animals survived without infection or haemorrhage. The grafted FD-APCS transplants dehydrated more rapidly in the first 14 days after implantation than the APCS transplants. The transparency of the FD-APCS transplants was restored quickly in the first postoperative 30 days and showed no signifificant difference in appearance from that of the APCS transplants at postoperative day 60. In addition, the light transmittance of the FD-APCS-transplanted corneas showed no signifificant difference comparing with the APCS-transplanted corneas and the native rabbit corneas within the wavelength range of 300-800 nm.
Conclusions :
This study indicated that the porous FD-APCS prepared using pancreatic phospholipase A2 is capable of serving as potential scaffold for constructing tissue-engineered cornea with biological properties.
This is a 2020 ARVO Annual Meeting abstract.