The behavior of alloplastic tympanic membranes in Staphylococcus aureus‐induced middle ear infection. I. Quantitative biocompatibility evaluation

Abstract

The biocompatibility of dense Silastic implants and porous implants made of Estane 5714 F1 polyether urethane, polypropylene oxide, and an HPOE/PBT segmented polyether polyester copolymer was evaluated during an induced Staphylococcus aureus middle ear infection. The middle ear response to infection seemed not to be affected by the presence of implants made of either of the polymers. Light microscopical morphometry and transmission electron microscopy showed degradation of the porous implants under study, but not of Silastic implants, which were invariably surrounded by a fibrous capsule. This finding, combined with the degree of porous implant degradation, the composition of the tissues surrounding the implants, and the tissue/biomaterial interface reactions are consistent with the results obtained in the noninfected middle ear. Round-cell infiltrates however, were predominantly associated with implants made of polypropylene oxide and HPOE/PBT copolymer; while the presence of (phagocytosed) microbial debris was associated with copolymer. The present findings indicate that with respect to implant behavior in infected surroundings Estane is the best porous material, whereas the behavior of Silastic implants did not deviate from that in non-infected ears.

Tissue engineering of the tympanic membrane using electrospun PEOT/PBT copolymer scaffolds: A morphological in vitro study

“…As a consequence, an ideal TM substitute is still the subject of investigation. Since the last century, synthetic biomaterial devices have been conceived by otologists as mere prosthetic replacements or, in the specific case of the eardrum, as sheeting substrates promoting TM self-repair via endogenous cell migration (25)(26)(27). From a TE perspective, the replacement is a functional biohybrid construct, which means a fully integrated cell/scaffold material.…”

“…In the 1990s, PEOT/PBT salt-casted 100-mm-thick porous films were proposed as TM replacements. The authors described epithelial layers covering the implant, and only a mild foreign body reaction in a rat model (26)(27)(28). The failure experienced using alloplastic substitutes to replace the TM has been explained by the necessity to design the correct material topography and degradation rate (28).…”

Biodegradable PEG-Based Amphiphilic Block Copolymers for Tissue Engineering Applications

“…PEGT-PBT membranes were initially developed and applied clinically for tympanic membrane reconstruction. 39,153–155 Subsequent studies aimed to apply bi-layer PLLA/PEGT-PBT membranes for skin regeneration. 156 Beumer et al found that dense PEGT-PBT films supported the proliferation of keratinocytes and fibroblasts, with the 40 wt.% PEG film supporting most comparable proliferation to TCPS.…”

Advancing Towards a Tissue-engineered Tympanic Membrane: Silk Fibroin as a Substratum for Growing Human Eardrum Keratinocytes

“…A group at the University of Leiden investigated a large number of synthetic polymers as potential materials for an artificial TM as a component of total artificial middle ear prostheses [15][16][17][18][19][20][21]. Biocompatibility of some commercially available silicone rubbers (Silastic Õ , MDX Õ ) and polyurethanes (Estane Õ , Pellethane Õ ), as well as of a poly(ethylene oxide-hydantoin)/poly(butylene terephthalate) segmented polyether-polyester copolymer (HPOE/ PBT) was extensively investigated [15][16][17][18][19]. These studies, which included in vitro attachment and growth of eardrum cells and in vivo implantation in rats, indicated that the porous HPOE/PBT was the most suitable, evoking no toxicity and only mild foreign-body reaction, allowing biointegration with the host tissue, and degrading slowly [20].…”