A better design is needed for clinical studies of chronic tympanic membrane perforations using biological materials

Abstract

We would like to address the manuscript entitled ''A new graft material for myringoplasty: bacterial cellulose'' by Biskin et al. [1]. The work describes a simple and convenient treatment strategy to repair chronic tympanic membrane perforation. However, the clinical study design has some shortcomings. The authors described how ''The edge of the perforation was de-epithelialized and sponges were inserted into the middle ear to prevent medialization of the graft material. Then, bacterial cellulose (BC) was placed over the perforation using an overlay grafting technique. After ten postoperative days, the sponges were removed. Using microscopy, the ears of all patients were examined weekly for the first postoperative month'' in their Operative Method section. According to the authors, the sponges were inserted into the middle ear, and then the perforation was covered by BC. It was unclear whether the BC was removed simultaneously with removal of the sponges at each examination, with a fresh piece of BC then placed over the perforation. In addition, we suggest that excision of the perforation margin and addition of the sponges represent confounding factors with respect to evaluating the operation success rate. 1. The edge of the perforation was de-epithelialized to make a fresh edge [1]. A previous study showed that excision of the perforation margin is a confounding factor because it induces an acute inflammatory response, potentially restarting the acute wound healing process [2, 3]. Animal studies have shown that injury is associated with epidermal and connective tissue hyperplasia of the tympanic membrane. Connective tissue hyperplasia may be increased by injury, and might stimulate the release of growth factors [4, 5]. Sponges are excellent biological materials and provide the scaffold for epithelial migration, thereby facilitating eardrum healing. A previous study suggested that Gelfoam could stimulate the inflammatory response of the perforation margin, resulting in the proliferation of granulation tissue and acceleration of eardrum repair [6]. Niklasson et al. reported a closure rate of 83 % in 18 chronic tympanic membrane perforations using a GelfoamVR (Pfizer, Brussels, Belgium) plug in combination with surgical removal of the perforation edges [7]. 2. The authors [1] reported an 81.2 % (13/16) success rate of myringoplasty using BC; Silveira et al. [8] reported a 66.6 % success rate with the same material. These success rates were not significantly superior to the success rate obtained with other biological materials. Park et al. [9] reported a success rate of 62.8 % (27/43) using thin cigarette paper alone in myringoplasty, while a closure rate of chronic tympanic membrane perforations of 73.7 % (14/19) was obtained using a collagen sponge alone [10]. In addition, the success rate using BC was inferior to that obtained using tragus cartilage or perichondrium myringoplasty. Vashishth et al. [11] reported a closure rate of 90.0 % for near-total or total perforations in a cartilage group. Albirmawy [12] and ...

Use of Industrial Wastes as Sustainable Nutrient Sources for Bacterial Cellulose (BC) Production: Mechanism, Advances, and Future Perspectives

“…BC possesses nanofibrillar and ultrafine structured material with an excellent combination of properties such as high flexibility and tensile strength (Young modulus of 114 GPa) [ 32 ], as well as high crystallinity (84–89%) [ 33 ]. Therefore, due to its outstanding mechanical properties, BC nanocomposites had been fabricated by reinforcing it with other polymers to be developed in various applications, including paper [ 29 ], treating tympanic membrane perforation [ 34 , 35 ], shielding film [ 36 ], food packaging films [ 37 ], audio speaker diaphragms [ 38 ], and so on. Development of BC for paper products had been actively conducted by Ajinomoto Corporation along with Mitsubishi Paper Mills in Japan since 1995 (JP patent 63295793) [ 39 ].…”