Micro- and nanoscale characterization of different natural biomaterials for ocular surface regeneration

Abstract

Objectives: This study aims to characterize the widely used biological derived membranes in clinics in termsof micro-nano scale mechanical and morphological properties. Within this scope, advanced platelet-rich fibrin(A-PRF), leucocyte-and platelet-rich fibrin (L-PRF) and human amniotic membrane were studied in thisresearch study.Methods: Nano-indentation, optical coherence tomography (OCT), scanning electron microscopy (SEM), andin vitro degradation test were performed for material characterization.Results: The nano-indentation test revealed significantly higher modulus of elasticity and hardness values inA-PRF group, while OCT presented significantly higher thickness measurements when compared L-PRF. Aloose 3D architecture formation due to the large pores formed by means of large fiber diameter were observedin A-PRF group. Besides, platelets were observed among the large fibers in A-PRF membranes on the contraryof L-PRF membranes. Low fiber diameter and high cellular separation were recorded in L-PRF group due tothe high centrifugal force application. Therefore, it was observed that the platelets were located mostly on thesurface of the membranes in L-PRF. The loose 3D architecture of A-PRF membranes is thought to releasegrowth factors for a longer period of time, ensuring cellular integrity. On the other hand, degradation test resultsindicated that amniotic membranes degrade to about 85% in one week, while L-PRF and A-PRF were losttheir initial weights approximately 31% and 40%, respectively.Conclusions: This comparative characterization study of three different natural biomaterials used in a widerange of clinical applications, from dentistry to ophthalmology, was thought to guide surgeons on the selectionof site-specific material