Nanoscale Topographical Characterization of Orbital Implant Materials

Marco Salerno,Andrea Reverberi,Francesco Baino

doi:10.3390/ma11050660

Marco Salerno, Andrea Reverberi + Show 1 more

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https://doi.org/10.3390/ma11050660

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Abstract

The search for an ideal orbital implant is still ongoing in the field of ocular biomaterials. Major limitations of currently-available porous implants include the high cost along with a non-negligible risk of exposure and postoperative infection due to conjunctival abrasion. In the effort to develop better alternatives to the existing devices, two types of new glass-ceramic porous implants were fabricated by sponge replication, which is a relatively inexpensive method. Then, they were characterized by direct three-dimensional (3D) contact probe mapping in real space by means of atomic force microscopy in order to assess their surface micro- and nano-features, which were quantitatively compared to those of the most commonly-used orbital implants. These silicate glass-ceramic materials exhibit a surface roughness in the range of a few hundred nanometers (Sq within 500–700 nm) and topographical features comparable to those of clinically-used “gold-standard” alumina and polyethylene porous orbital implants. However, it was noted that both experimental and commercial non-porous implants were significantly smoother than all the porous ones. The results achieved in this work reveal that these porous glass-ceramic materials show promise for the intended application and encourage further investigation of their clinical suitability.

Highlights

The morphological properties of biomedical implant surfaces are known to greatly influence the cell and tissue responses in vitro and in vivo [1,2,3,4]
The present study aims at expanding those microscopy (SEM) and stylus profilometry [18]
All the samples were successfully imaged by atomic force microscopy (AFM), despite the occasional occurrence of some local defects such as partial line strikes (Figure 3c,d) and apparent contaminant particles overlaying the sample surface (Figure 3b), which were removed by the scan area considered for quantitative analysis by means of image masking

Summary

Introduction

The morphological properties of biomedical implant surfaces (e.g., texture, roughness) are known to greatly influence the cell and tissue responses in vitro and in vivo [1,2,3,4]. Studies carried out in the 1990s on metallic prosthetic implants provided the first evidence that osteoblastic cells preferably attach and spread on titanium surfaces exhibiting a diffused micro-scale roughness [2,5,6]. There are some biomedical applications for which the presence of a surface microor nano-roughness may not be a goal and should be minimized (e.g., cardiovascular devices (heart valves, coronary stents) [9] and orbital implants [10]). Orbital implants substitute a diseased ocular globe after its surgical removal through enucleation due to either cancer

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