Yoshiharu Kitani

Regenerative Treatment for Tympanic Membrane Perforation

Objective: To establish a tissue engineering therapy for the treatment of large tympanic membrane perforation (TMP) without the need for conventional surgical therapy. Study Design: Randomized control trial. Setting: General hospital. Patients and Methods: A total of 63 chronic TMPs were randomly selected from outpatients. Intervention: Of the total 63 chronic TMPs, 53 were randomly assigned to the basic fibroblast growth factor (b-FGF) group and the remaining 10 were randomly assigned to the control group. Materials used for the TM repair were gelatin sponge and fibrin glue with/without b-FGF. After creating a mechanical disruption of the edge of the TMP, a gelatin sponge was immersed in b-FGF or saline (for the control group) and placed over the perforation. Fibrin glue was dripped over the sponge as a sealant. Main Outcome Measures: The effectiveness of this therapy was evaluated by closure rates, hearing level, and sequelae 3 weeks after treatment. The treatment was repeated up to 4 times for cases in which complete closure of the TMP was not achieved after 1 round of treatment. Results: Complete closure of the TMP was achieved in more than 98.1% (52/53) of the patients in the b-FGF group and 10% (1/10) of the patients in the control group. The average hearing level of all patients with successful TM repair was improved. Serious sequelae were not observed in any patient. Conclusion: This study demonstrates that a combination of gelatin sponge, b-FGF, and fibrin glue enables the regeneration of the TM without conventional operative procedures. This innovative regenerative therapy is an easy, safe, cost-effective, and minimally invasive outpatient treatment.

Chronic vocal fold scar restoration with hepatocyte growth factor hydrogel

Therapeutic challenges exist in the management of vocal fold scarring. We have previously demonstrated the therapeutic potential of hepatocyte growth factor (HGF) in the management of acute phase vocal fold scarring using a novel hydrogel‐based HGF drug delivery system (DDS). However, the effect of HGF on matured vocal fold scarring remains unclear. The current study aims to investigate the effect of HGF‐DDS on chronic vocal fold scarring using a canine model.

Increased Expression of Phosphatidylcholine (16:0/18:1) and (16:0/18:2) in Thyroid Papillary Cancer

A good prognosis can be expected for most, but not all, cases of thyroid papillary cancer. Numerous molecular studies have demonstrated beneficial treatment and prognostic factors in various molecular markers. Whereas most previous reports have focused on genomics and proteomics, few have focused on lipidomics. With the advent of mass spectrometry (MS), it has become possible to identify many types of molecules, and this analytical tool has become critical in the field of omics. Recently, imaging mass spectrometry (IMS) was developed. After a simple pretreatment process, IMS can be used to examine tissue sections on glass slides with location information. Here, we conducted an IMS analysis of seven cases of thyroid papillary cancer by comparison of cancerous with normal tissues, focusing on the distribution of phospholipids. We identified that phosphatidylcholine (16:0/18:1) and (16:0/18:2) and sphingomyelin (d18:0/16:1) are significantly higher in thyroid papillary cancer than in normal thyroid tissue as determined by tandem mass (MS/MS) analysis. These distributional differences may be associated with the biological behavior of thyroid papillary cancer.

Implantation of an atelocollagen sponge with autologous bone marrow-derived mesenchymal stromal cells for treatment of vocal fold scarring in a canine model.

Objectives: Vocal fold scarring remains a therapeutic challenge. A new regenerative approach is needed to restore disorganized extracellular matrix. Tissue regeneration requires appropriate cells and a scaffold. Bone marrow–derived mesenchymal stromal cells (BMSCs) are multipotent and secrete many kinds of growth factors to regenerate tissues. Atelocollagen sponges have many large pores that permit cell entry. The present study was performed to evaluate whether implantation of an atelocollagen sponge plus BMSCs is effective for the treatment of vocal fold scarring. Methods: Twelve beagles underwent implantation of an atelocollagen sponge or of an atelocollagen sponge with autologous BMSCs (1.0 × 106 cells) in the subepithelial pockets of scarred vocal folds. Six months after the operation, vibratory examinations and histologic examinations were performed. Results: Mucosal vibrations improved significantly for the atelocollagen sponge–implanted vocal folds. Histologic analyses revealed favorable restoration of the extracellular matrix in the lamina propria. Increased distribution of hyaluronic acid and decreased dense collagen deposition were also noted. These improvements were enhanced by implantation of BMSCs. Conclusions: Implantation of atelocollagen sponges with autologous BMSCs into scarred vocal folds significantly increased hyaluronic acid distribution and decreased dense collagen deposition in the lamina propria, leading to better mucosal vibration.

Atelocollagen Sponge as a Stem Cell Implantation Scaffold for the Treatment of Scarred Vocal Folds

Objectives: Treatment of vocal fold scarring remains a therapeutic challenge. Our group previously reported the efficacy of treating injured vocal folds by implantation of bone marrow—derived stromal cells containing mesenchymal stem cells. Appropriate scaffolding is necessary for the stem cell implant to achieve optimal results. Terudermis is an atelocollagen sponge derived from calf dermis. It has large pores that permit cellular entry and is degraded in vivo. These characteristics suggest that this material may be a good candidate for use as scaffolding for implantation of cells. The present in vitro study investigated the feasibility of using Terudermis as such a scaffold. Methods: Bone marrow—derived stromal cells were obtained from GFP (green fluorescent protein) mouse femurs. The cells were seeded into Terudermis and incubated for 5 days. Their survival, proliferation, and expression of extracellular matrix were examined. Results: Bone marrow—derived stromal cells adhered to Terudermis and underwent significant proliferation. Immunohistochemical examination demonstrated that adherent cells were positive for expression of vimentin, desmin, fibronectin, and fsp1 and negative for beta III tubulin. These findings indicate that these cells were mesodermal cells and attached to the atelocollagen fibers biologically. Conclusions: The data suggest that Terudermis may have potential as stem cell implantation scaffolding for the treatment of scarred vocal folds.

Transforming growth factor β3 for the prevention of vocal fold scarring

Vocal fold scarring poses a therapeutic challenge. It causes hoarseness and decreases the quality of life. Transforming growth factor β3 (TGFβ3) is highly expressed in fetal wounds that heal without scarring, and administration of TGFβ3 has been reported to prevent scarring of the skin and the buccal mucosa. Thus TGFβ3 is considered to be a key molecule in scar‐free healing. This study aimed to examine the ability of TGFβ3 to prevent vocal fold scarring, with particular attention paid to the distribution of extracellular matrices and functional outcomes.

The protective efficacy of basic fibroblast growth factor in radiation‐induced salivary gland dysfunction in mice

Radiotherapy is one of the most effective treatments for head and neck cancer. However, in addition to the target tumor, normal salivary glands are also included in the irradiation field. This unavoidably results in dry mouth syndrome as a side effect. In this study, the protective efficacy of basic fibroblast growth factor (bFGF) was investigated in radiation‐damaged salivary glands.

Prevention of buccal mucosa scarring with transforming growth factor β3

In the treatment of tumorous diseases, scarring often forms after resection or irradiation. Scarring of the buccal mucosa causes difficulty in opening the mouth and mastication, decreasing quality of life. Transforming growth factor (TGF) β3 is an isoform of TGFβ1 that is known to accelerate scarring, although it has different effects on wound healing. TGFβ3 administration into wounds has been associated with improvement in the quality of healing skin in vivo. TGFβ3 is also considered to be an important anti‐scarring factor in buccal mucosa. The present study aimed to examine whether TGFβ3 is effective for prevention and treatment of buccal mucosa scarring.

Glottic regeneration with a tissue-engineering technique, using acellular extracellular matrix scaffold in a canine model†

Acellular extracellular matrix scaffold derived from porcine urinary bladder (UBM) is decellularized material that has shown success for constructive remodelling of various tissues and organs. The regenerative effects of UBM were reported for the tympanic membrane, oesophagus, trachea, larynx, pleura and pericardium in animal studies, with promising results. The aim of this study was to investigate the regenerative effects of UBM on hemilarynx, using a canine model. A left partial hemilaryngectomy was performed and the surgical defects were reconstructed by insertion of UBM scaffold. Although local infection was observed in one dog in 1 week after implantation of the scaffold, all dogs showed good re‐epithelialization with minimum complication in 1 month. The effect of regeneration of the larynx was evaluated 6 months after the operation. The excised larynx experiments were performed to measure phonation threshold pressure (PTP), normalized mucosal wave amplitude (NMWA) and normalized glottal gap (NGG). The results of the measurements showed that PTP was normal or near normal in two cases and NMWA was within normal range in three cases, although there were individual variations. Histological examination was completed to evaluate structural changes in the scaffold with the appearance of the new cartilaginous structure. However, the regenerated vocal fold mucosa was mostly scarred. The UBM scaffold has shown to be biocompatible, biodegradable and useful for tissue regeneration of the hemilarynx, with possible restoration of function of the vocal fold. The vocal fold mucosa was scarred, which is the next challenge to be addressed. Copyright

Functional regeneration of laryngeal muscle using bone marrow–derived stromal cells

To investigate the functional efficiency of skeletal muscles regenerated by transplantation of bone marrow–derived stromal cells (BSCs) or induced‐muscle progenitor cells (IMCs) as assessed in the canine posterior cricoarytenoid (PCA) muscle injury model.