Transplantation of autologous bone marrow-derived mononuclear cells into cerebrospinal fluid in a canine model of spinal cord injury.

Introduction: Spinal cord injury (SCI) is associated with severe dysfunction of nervous tissue, and repair via the transplantation of bone marrow-derived mononuclear cells (BM-MNCs) into cerebrospinal fluid yields promising results. It is essential to understand the underlying mechanisms; therefore, this study aimed to evaluate the regenerative potential of autologous BM-MNC transplantation in a canine model of acute SCI. Methods: Six dogs were included in this study, and SCI was induced using an epidural balloon catheter between L2 and L3, particularly in the area of the anterior longitudinal ligament. BM-MNC transplantation was performed, and T2-weighted magnetic resonance imaging (MRI) was conducted at specific time points (i.e., immediately after inducing SCI and at 1, 2, and 4 weeks after inducing SCI); moreover, the expression of growth-associated protein 43 (GAP-43) was evaluated. Results: MRI revealed that the signal intensity reduced over time in both BM-MNC-treated and control groups. However, the BM-MNC-treated group exhibited a significantly faster reduction than the control group during the early stages of SCI induction (BM-MNC-treated group: 4.82 ± 0.135 cm [day 0], 1.71 ± 0.134 cm [1 week], 1.37 ± 0.036 cm [2 weeks], 1.21 cm [4 weeks]; control group: 4.96 ± 0.211 cm [day 0], 2.49 ± 0.570 cm [1 week], 1.56 ± 0.045 cm [2 weeks], 1.32 cm [4 weeks]). During the early stages of treatment, GAP-43 was significantly expressed at the proximal end of the injured spinal cord in the BM-MSC-treated group, whereas it was scarcely expressed in the control group. Conclusions: In SCI, transplanted BM-MNCs can activate the expression of GAP-43, which is involved in axonal elongation (an important process in spinal cord regeneration). Thus, cell therapy with BM-MNCs can provide favorable outcomes in terms of better regenerative capabilities compared with other therapies.

Radiologic evaluation of compensatory lung growth using computed tomography by comparison with histological data from a large animal model.

Non-invasive analysis using computed tomography (CT) data may be a promising candidate to evaluate neo-alveolarization in adult lungs following lung resection. This study evaluates and compares the validity of CT analysis with histologic morphometry for compensatory lung growth in a large animal model. We calculated the radiologic tissue volume and the radiologic lung weight from CT data taken at 1, 3, and 6 months post-surgery on 15 male beagle dogs that had a right thoractotomy, bilobectomy, or pneumonectomy (n = 5 in each group). Results were analyzed using one-way ANOVA and were subsequently compared to histologic findings of tissue samples at 6 months post-surgery using Pearson's correlation. An increase in radiologic tissue volume and radiologic lung weight was identified, which was positively correlated with histologic lung parenchymal amounts (correlation coefficient = 0.955 and 0.934, respectively, p < 0.001). Histology of lung specimens at 6 months post-surgery revealed an increase in the tissue amount in both Bilobectomy and Peumonectomy groups, which was consistent with compensatory lung growth. Radiologic tissue volume and radiologic lung weight reflected compensatory lung growth following lung resection. Radiologic assessment using CT data can be a promising clinical modality to evaluate postoperative lung growth.

"Idiopathic" Shoulder Pain and Dysfunction from Carpal Tunnel Syndrome and Cubital Tunnel Syndrome.

As a referral center for chronic pain, we see many patients with "idiopathic" shoulder pain and limited range of motion. The combination of mild or subclinical carpal tunnel syndrome and cubital tunnel syndrome may be an underrecognized etiology of symptoms in such patients. Here, we report our treatment algorithm and results for such patients. METHODS: Of patients with a chief complaint of shoulder pain, we identified 56 consecutive patients who had pain or tingling with median nerve compression at the proximal wrist crease and positive Tinel's around the cubital tunnel. They were first provided a night-time wrist orthosis. If still symptomatic, nerve blocks were given to median and ulnar nerves under ultrasound guidance. If symptoms recurred after nerve blocks, nerve conduction studies and surgical release of affected nerves were performed. RESULTS: Six patients had 60% or more pain relief with orthosis (mean 4.7 ± 0.8 (SD) to 2.2 ± 0.8). Twenty-three patients had nerve blocks and had persistent pain relief (6.0 ± 1.7 to 2.1 ± 1.9) and significant shoulder motion improvement. Twenty-seven patients only had temporal relief and required surgery but postoperatively had persistent pain relief (6.2 ± 2.0 to 1.2 ± 1.0) and improved shoulder motion. qDASH improved from 33.4 ± 20.1 preoperatively to 12.2 ± 7.4 postoperatively. CONCLUSIONS: All patients had substantial improvement in shoulder pain and motion with compressive neuropathy treatments. Targeted physical examination can identify these patients, who can have significant improvement with appropriate diagnosis and treatment. The study sheds light on an underrecognized cause of shoulder dysfunction.

Surgical assistant manipulator with diagonal joints and multi-stage telescopic screws for laparoscopic solo surgery.

PURPOSE: A surgeon in a sterilized area can perform robotically assisted laparoscopic solo surgery while controlling a laparoscope-holding robot for view stabilization and a forceps robot for pulling organs. At present, no locally operated surgical assistant manipulator with a mechanical remote center of motion (RCM) is available to operate within a small space while providing a wide range of movement. The present study describes a new locally operated detachable end-effector manipulator (LODEM) with diagonal joints and multi-stage telescopic screws. METHODS: A forceps manipulator attached to commercial surgical forceps was developed. This manipulator uses RCM diagonal joints for the yaw and pitch axes, providing an intuitive pivot point and free rotation, and telescopic nested screws with multiple sliders clamp the commercial forceps for the axis of insertion. The manipulator placed above the abdominal wall using a fixed arm connected to a bed rail is motor controlled by a handheld interface with button switches for precise traction and is controlled manually for easy rough positioning. RESULTS: Positional accuracy at the tip with a load of 5 N was under 0.5 mm. Mechanical deflection was under 2.1 mm. The manually controlled force was under 4.4 N. Successful simulated laparoscopic cholecystectomy using the prototype manipulator to handle the target and maintain stability was performed on a surgically realistic gallbladder model. CONCLUSIONS: A LODEM with diagonal joints and multi-stage telescopic screws was developed to facilitate minimally invasive, robotically assisted laparoscopic solo surgery by a surgeon working near the patient. This electric motor-controlled laparoscopic instrument holder by the surgeon in the surgical field could be used for such applications.

Anorectal Transplantation: The First Long-term Success in a Canine Model.

OBJECTIVE: Anorectal transplantation is a challenging procedure but a promising option for patients with weakened or completely absent anorectal function. SUMMARY BACKGROUND DATA: We constructed a canine model of anorectal transplantation, evaluated the long-term outcomes, and controlled rejection and infection in allotransplantation. METHODS: In the pudendal nerve function study, 6 dogs were randomly divided into 2 groups, transection and anastomosis, and were compared with a control using anorectal manometry, electromyography, and histological examination. In the anorectal transplantation model, 4 dogs were assigned to 4 groups: autotransplant, allotransplant with immunosuppression, allotransplant without immunosuppression, and normal control. Long-term function was evaluated by defecography, videography, and histological examination. RESULTS: In the pudendal nerve function study, anorectal manometry indicated that the anastomosis group recovered partial function 6 months postoperatively. Microscopically, the pudendal nerve and the sphincter muscle regenerated in the anastomosis group. Anorectal transplantation was technically successful with a 3-stage operation: colostomy preparation, anorectal transplantation, and stoma closure. The dog who underwent allotransplantation and immunosuppression had 2 episodes of mild rejection, which were reversed with methylprednisolone and tacrolimus. The dog who underwent allotransplantation without immunosuppression had a severe acute rejection that resulted in graft necrosis. Successful dogs had full defecation control at the end of the study. CONCLUSIONS: We describe the critical role of the pudendal nerve in anorectal function and the first long-term success with anorectal transplantation in a canine model. This report is a proof-of-concept study for anorectal transplantation as a treatment for patients with an ostomy because of anorectal dysfunction.

Replacement of a 5-cm Intrathoracic Trachea With a Tissue-Engineered Prosthesis in a Canine Model.

BACKGROUND: Critical obstacles must be addressed before clinical application of artificial tracheas. The major complications of long tracheal replacement include anastomotic dehiscence and stenosis owing to poor vascularity and incomplete reepithelialization. The objective of this report was to clarify whether preincubation of the prosthesis in the omentum could be applicable for reconstruction of a long segment of the intrathoracic trachea in a canine model. METHODS: The framework of an artificial trachea was fabricated from a polypropylene mesh tube and coated with 1% neutral atelocollagen inside and outside the lumen. The prosthesis was placed in the omentum of 9 healthy male beagle dogs for 3 weeks. Then, the pedicled prosthesis was used to replace a 50-mm-long section of intrathoracic trachea. Results were evaluated bronchoscopically, macroscopically, and histologically. RESULTS: After 3 weeks of abdominal incubation, the prostheses were incorporated into the host tissue. None of the dogs showed dehiscence of the anastomosis or infection of the prostheses during the postoperative period. Seven of the 9 dogs survived for more than 1 year. One dog died of a bowel obstruction resulting from a diaphragmatic hernia 3 months after replacement, and another died due to reasons unrelated to the prosthesis at 6 months. Bronchoscopic examination revealed no stenosis or dehiscence, and microscopic examination of all dogs showed that the luminal surface was covered by newly regenerated connective tissue and respiratory epithelium. CONCLUSIONS: Pedicled omentum-prosthesis complexes may allow successful reconstruction of a long segment of the intrathoracic trachea.

Pathological changes within two weeks following spinal cord injury in a canine model.

PURPOSES: This study aimed to investigate the histopathological changes that occur within 2 weeks following spinal cord injury (SCI) in dogs. METHODS: Eight adult female Beagle dogs were included in this study, and SCI was induced using an epidural balloon catheter. Two dogs were killed at each of the following four time points: immediately after the procedure and 1 day, 1 week, and 2 weeks after the procedure. Neurological status was evaluated with five categories. Histopathological changes were visually observed for stained sections of formalin-fixed spinal cord to evaluate hemorrhage, spongiosis, necrosis, and gliosis morphologically. RESULTS: Along the 2 weeks post-injury, severe hemorrhage was observed at the primary injury site, the average diameter of which expanded quickly from 8 to 10 mm in 1 day and then decreased to 5 mm in 1 week. This indicates that the bleeding cavity expanded at the initial injury site to produce ascending and descending hemorrhage. The hemorrhage at the injury site resolved in 2 weeks. In contrast, spongiosis, parenchymal necrosis, and gliosis were first inconspicuous or mild and then became severe in 1 week or 2 weeks. Hemorrhage, hematoma, and other similar changes occurred at the regions approximately 20-mm rostral and caudal to the primary injury site. These changes were observed in both gray matter and white matter. CONCLUSIONS: This study is the first to assess the sequential histopathological changes in the acute and intermediate phases following SCI in dogs. Our findings enhance the usefulness of the canine intervertebral disk disease model in the assessment of secondary spinal cord histopathology in human SCI.

Locally operated assistant manipulators with selectable connection system for robotically assisted laparoscopic solo surgery.

PURPOSE: By integrating locally operated surgical assistant robots in a sterilized area, a surgeon can perform safe robotically assisted laparoscopic solo surgery while controlling a laparoscope-holding robot and a forceps robot. At present, there is no leader-follower control system with switchable connection for the leader device in which each assistant follower robot can provide the manipulation intuitively and easily. In the present study, a new locally operated leader-follower selectable control system has been developed. METHODS: The leader-follower system was developed to connect one leader operating device and one of two selectable follower assistant manipulator devices with different numbers of axes, kinematics models, sensors, and actuators for view stabilization and pulling organs. The system is constructed using the middleware of the ORiN-based medical robot architecture MRLink. The system is regulated by the robot integrator application with unilateral leader-follower PTP using the relative displacement between the leader device and the selected follower device through providers of device interface including the information and control commands. RESULTS: The execution cycle for updating the position was 50 ms, and the time delay to catch up with the same position was 100 ms. Two assistant manipulators controlled by the leader-follower selectable system could successfully produce the desired view and handle the target organ model for 17 min in a simulated laparoscopic cholecystectomy. CONCLUSIONS: A locally operated leader-follower selectable control system was constructed to facilitate minimally invasive, robotically assisted laparoscopic solo surgery by a doctor working near the patient. This system could be used for such applications.

Bone regeneration utilizing a newly developed octacalcium phosphate/weakly denatured collagen scaffold.

INTRODUCTION: Autologous bone grafting or various bone-regenerating materials are used to treat bone defects caused by tumor resection and accident trauma. Octacalcium phosphate, a reasonable bone regenerative material, activates osteoblasts. We fabricated a composite material, octacalcium phosphate/weakly denatured collagen, as a new scaffold. We aimed to investigate the osteoregenerative effect of the octacalcium phosphate/weakly denatured collagen scaffold (compared with that of weakly denatured collagen) in skull defects in a canine model. METHODS: Atelocollagen was extracted from porcine skin via pepsin treatment. The weakly denatured collagen scaffold was fabricated with a freeze-dried and thermally crosslinked atelocollagen suspension at pH 7.4. Octacalcium phosphate was synthesized using Ca-acetate and NaH2PO4. Octacalcium phosphate particles (diameter, 199-298 µm) were mixed with a collagen matrix to fabricate an octacalcium phosphate/weakly denatured collagen scaffold. Bilateral defects (diameter, 10 mm; full-thickness) were induced in dog skulls, and the octacalcium phosphate/weakly denatured collagen and weakly denatured collagen scaffolds were implanted into the defects. RESULTS: Eight weeks after implantations, bone regeneration was evaluated via histopathological analysis. It revealed osteoblast infiltration and osteoregeneration in all defects treated with the octacalcium phosphate/weakly denatured collagen scaffold. The defects treated with weakly denatured collagen scaffold or without any scaffold mostly contained connective tissue, with no neo-osteogenesis. DISCUSSION: The novel octacalcium phosphate/weakly denatured collagen scaffold better promotes osteoregeneration than the weakly denatured collagen scaffold; this "in situ tissue engineering" approach is potentially clinically applicable for bone reconstruction.

Evaluation of regenerated tracheal cilia function on a collagen-conjugated scaffold in a canine model.

OBJECTIVES: It is unclear whether the movement and function of the regenerated cilia on collagen-conjugated artificial trachea are the same as those of normal cilia. This study assessed the ciliary beat frequency (CBF) and ciliary transport functions (CTFs) of regenerated cilia in a canine model. METHODS: A tracheal defect introduced into the anterior portion of the cervical trachea of an adult beagle dog was covered with a collagen-conjugated prosthesis. Two months later, the trachea was harvested along the long axis, both from normal and regenerated regions. The cilia were stained with isothiocyanate-conjugated wheat germ agglutinin, and their movement was monitored with a high-speed camera to analyse CBF and CTF. Four samples each were obtained from the regenerated and normal regions for CBF analysis and 7 samples each were obtained for CTF analysis. RESULTS: The wheat germ agglutinin-stained cells showed well-regulated beats in both the regenerated and normal regions of the trachea. Mean CBF in the regenerated and normal regions did not differ significantly (7.11 ± 0.41 vs 7.14 ± 1.09 Hz; P = 981). By contrast, CTF was significantly lower in the regenerated region than in the normal region (30.0 ± 6.62 vs 7.43 ± 0.58 µm/s; P = 0.005). CONCLUSIONS: Mean CBF in the regenerated and normal regions did not differ significantly at 2 months. The CTF in the regenerated region recovered partially but remained lower than those in the normal region. Methods are needed to improve the CTF of regenerated cilia.

Regenerated nephrons in kidney cortices ameliorate exacerbated serum creatinine levels in rats with adriamycin nephropathy.

Kidney regeneration could be classified into 2 groups: kidney generation and kidney repair. We have attempted in vivo nephron generation for kidney repair, as a therapy for chronic renal failure (CRF), by exploiting cellular interactions via conditioned media. In the previous report, we demonstrated the generation of rich nephrons in rat intact kidney cortices through percapsular injection of mesenchymal stem cell (MSC)-differentiated tubular epithelial cells (TECs) after pretreatment of 3-dimensional culture using a small amount of gel complex and condensed medium. In this study, to verify the amelioration of serum creatinine (sCr) levels by regenerated nephrons in rats with CRF, we first created damaged kidneys through systemic administration of adriamycin, and implanted the pretreated MSC-differentiated TECs into unilateral kidney cortices 2 weeks after adriamycin administration (A-2W, that is I-0W). After recovery of acute kidney injury, the control rats without cell implantation showed re-exacerbation of sCr levels, resulting in death within A-12W. Alternatively, the cell-implanted rats had a formation of mature nephrons in I-3W, and showed significant amelioration of sCr levels in I-7W. As a result, these rats could live until euthanization in I-12W or I-16W, indicating the utility of cell injection therapy into a kidney (K-CIT) for CRF. We expect that our K-CIT or the refined methods will be applied to patients with CRF.

First clinical application of radiofrequency identification (RFID) marking system-Precise localization of a small lung nodule.

OBJECTIVES: Precise small lung nodule resection is challenging in minimally invasive thoracoscopic surgery. Various methods that help surgeons to locate the target nodule have been devised; however, the ideal way that satisfies the demand has not yet been realized. We have developed and applied a novel marking system to localize small lung nodules for the first time in humans. METHODS: A radiofrequency identification tag (1.8 mm in diameter and 7 mm in length) that can communicate with a wand-shaped antenna (10 mm in diameter) from the distance of 3 cm was prepared. The tag was delivered adjacent to a 7-mm subsolid nodule in the right lower lobe of a patient under cone beam computed tomography guidance and video-assisted thoracoscopic surgery wedge resection was subsequently performed. RESULTS: The delivery of the tag was smooth, and the tag was almost immediately detected by the antenna. Wedge resection was successfully performed with the guiding signal from the tag. CONCLUSIONS: We have so far demonstrated that this technology could be applicable for small lung nodule detection in preclinical studies. In this first clinical experience, this system proved to provide accurate positional information of small lung nodules with depth.

Improved Healing by Adjuvant Osteoconductive Therapy Using a Novel Cotton-Like Hydroxyapatite Sheet After Median Sternotomy.

The union rate of wire fixation after median sternotomy remains unsatisfactory. We developed a novel osteoconductive sheet composed of hydrophilized hydroxyapatite and evaluated its osteogenetic effect when interposed between sternal halves in a canine model. Eighteen canines were divided equally into groups based on the hemostatic agent used: osteoconductive sheet (S), none (C), and bone wax (BW). After median sternotomy, the sternal halves were closed by wire fixation. In each group, 3 canines were euthanized at 1 month, while 3 were euthanized at 2 months. Resected sternums were mechanically assessed by the 3-point bending test, radiographically assessed by micro-CT, and pathologically assessed to quantify the osteogenesis between sternal halves. Compared with the BW group, the S group had a greater maximum stress at 1 month (S: 322.9 ± 107.7 N, C: 233.0 ± 62.7 N, BW: 124.9 ± 88.4 N; P = 0.025), and greater maximum shear force at 1 month (S: 1.92 ± 0.67 N/m2; C: 1.23 ± 0.28 N/m2; BW: 0.68 ± 0.41 N/m2; P = 0.025). Micro-CT revealed that the S group had more osteogenesis than the BW group at 1 month (25.7% ± 9.8% vs 6.9% ± 9.2%), and 2 months (34.0% ± 15.1% vs 14.8% ± 9.4%); the respective values in the C group were 17.1% ± 7.2% and 29.7% ± 9.3%. Pathologic examination revealed that the S group had the greatest osteogenetic area at 2 months (S: 38.8% ± 18.8%; C: 24.5% ± 6.9%; BW: 24.7% ± 18.6%). Adjuvant osteoconductive therapy using a cotton-like hydroxyapatite sheet in addition to wire fixation significantly improved sternal healing compared with BW. This new material also showed relatively better outcome than the C group.

A novel suction-based lung-stabilizing device in single-port video-assisted thoracoscopic surgical procedures.

OBJECTIVE: Single-port video-assisted thoracoscopic surgery (SPVATS) has become a subject of interest for thoracic surgeons in recent years; however, it has not been fully accepted partly because the procedure is technically demanding. We speculate that the most critical problem of SPVATS is that significant interferences of the instruments may occur during the procedure because all the instruments share only a single incisional port. The purpose of this study was to evaluate the usability of a new suction-based lung-stabilizing device during SPVATS procedure. METHODS: We developed a novel suction-based lung-stabilizing device equipped with three hemispheric silicon suction cups. Ten cases of canine's lower lobectomies were performed. Five cases were performed without this device and designated as the control cases. The remaining cases were performed using this device and were designated as the experimental cases. RESULTS: A significantly fewer number of interruption times were noted in the novel lung-stabilizing device group than in the control group (average, 0.4 vs. 4.4; P = 0.0031). Although the differences did not reach statistical significance, the device tended to demonstrate better performance compared with the control group regarding the operation time, organ damage, and accomplishment of SPVATS. CONCLUSION: Our study indicates that the novel lung-stabilizing device has potentially useful applications in SPVATS procedures.

Nephron generation in kidney cortices through injection of pretreated mesenchymal stem cell-differentiated tubular epithelial cells.

Transplantation of artificially treated metanephroi or pluripotent stem cell-injected blastocyst-derived whole kidneys will be established in the near future as a useful therapeutic method for renal failure. We have attempted in vivo nephron generation for kidney repair by exploiting cellular interactions via conditioned media (CMs). In a previous report, we showed stimulative cross-talks between vascular endothelial cells (VECs) and tubular epithelial cells (TECs) on cell proliferation and morphological changes, the differentiation of mesenchymal stem cells (MSCs) into TECs by TEC-CM, and nephron generation from TECs or MSCs in rat subcutaneous spaces. In this study adding collecting duct cells (CDCs) and their CM, we demonstrate the suppressive actions of CDC-CM against VECs and TECs, in addition to stimulative cross-talks between VECs and TECs, during the above changes. Furthermore, CDC-CM, similar to TEC-CM, caused differentiation of MSCs into TECs. Thus, we injected CDC-CM-induced MSC-differentiated TECs into rat kidney cortices. The pretreatment of cells in 3-dimensional culture using a small amount of gel complex before implantation triggered the generation of much more nephron-like structures, compared to the implantation of non-pretreated cells. Our method of injecting pretreated TECs into kidney cortices might have applications for repairing dysfunctional kidney tissue.

The Ratios of monounsaturated to saturated phosphatidylcholines in lung adenocarcinoma microenvironment analyzed by Liquid Chromatography-Mass spectrometry and imaging Mass spectrometry.

Adenocarcinoma is the most common type of lung cancer, and can be classified into various histologic subtypes. However, little is known about the subtype-dependent variations in lipid metabolism processes. We performed dual lipidomic analyses using liquid chromatography-mass spectrometry (LC-MS) and matrix-assisted laser desorption/ionization imaging mass spectrometry (MALDI-IMS) to identify possible biomarkers to distinguish adenocarcinoma specimens from normal lung specimens, and to determine if there are any differences in lipid metabolism among the histologic subtypes (lepidic, acinar, papillary, micropapillary, solid, and mucinous). LC-MS was used to characterize the lipid profiles of lung adenocarcinoma and normal lung tissue, and MALDI-IMS analysis was performed to confirm the results with information on lipid localization within the lung. LC-MS analysis found significant differences in the relative abundances of phosphatidylcholine (PC)(16:0/16:0) (P = 0.0432) and sphingomyelin (SM)(42:2) (P < 0.0001) between adenocarcinoma and normal lung specimens. The ratios of PC(16:0/16:1)/PC(16:0/16:0), PC(16:0/18:1)/PC(16:0/16:0), and PC(16:0/18:1)/PC(16:0/18:0) were significantly higher in adenocarcinoma specimens (P = 0.02221, P = 0.0004, and P = 0.0215, respectively). MALDI-IMS analysis confirmed that these ratios were significantly higher in adenocarcinoma regions of the lung. The ratio of PC(16:0-18:1)/PC(16:0-18:0) was significantly lower in solid subtypes than in other subtypes (P = 0.0028). The monounsaturated/saturated PC ratios may have applications in adenocarcinoma diagnoses and subtyping.

Transplantation of multiciliated airway cells derived from human iPS cells using an artificial tracheal patch into rat trachea.

Tracheal resection is often performed for malignant tumours, congenital anomalies, inflammatory lesions, and traumatic injuries. There is no consensus on the best approach for the restoration of tracheal functionality in patients with tracheal defects. Artificial grafts made of polypropylene and collagen sponge have been clinically used by our group. However, 2 months are required to achieve adequate epithelialization of the grafts in humans. This study aimed to investigate the feasibility of transplantation therapy using an artificial trachea with human-induced pluripotent stem cell (hiPSC)-derived multiciliated airway cells (hiPSC-MCACs). Collagen vitrigel membrane, a biocompatible and absorbable material, was used as a scaffold to cover the artificial trachea with hiPSC-MCACs. Analyses of hiPSC-MCACs on collagen vitrigel membrane were performed by immunocytochemistry and electron microscopy and by assessing ciliary beat frequency. Along with the artificial trachea, hiPSC-MCACs were transplanted into surgically created tracheal defects of immunodeficient rats. The survival of transplanted cells was histologically evaluated at 1 and 2 weeks after the transplantation. The hiPSC-MCACs exhibited motile cilia on collagen vitrigel membrane. The surviving hiPSC-MCACs were observed in the endotracheal epithelium of the tracheal defect at 1 and 2 weeks after transplantation. These results suggest that hiPSC-MCAC is a useful candidate for tracheal reconstruction.

Collagen sponge scaffolds containing growth factors for the functional regeneration of tracheal epithelium.

Tracheal epithelia have barrier and mucociliary clearance functions that prevent invasion of extraneous particles and infectious materials. Hence, following tracheal reconstructions, functional and morphological regeneration of epithelia is required to prevent respiratory declines and infectious diseases. Although growth factors (GFs) promote the regeneration of tracheal epithelial morphologies, it remains unclear whether tracheal grafts containing GFs are beneficial for regeneration of tracheal epithelial functions. Thus, we fabricated collagen sponge scaffolds containing insulin-like GF-1 (IGF-1) and the basic fibroblast, hepatocyte, and epidermal GFs (bFGFs, HGFs, and EGFs, respectively), and we evaluated the effects of the grafts on the functional regeneration of tracheal epithelia. Partial tracheal defects were imposed surgically, and collagen sponges containing IGF-1, bFGF, HGF, or EGF were then transplanted to defect sites. Subsequent immunofluorescence studies suggested that EGF and bFGF contribute to regular distributions of tight junction molecules, and tracer permeability assays suggested that EGF and bFGF promote regeneration of barrier function. Increased ciliogenesis was also observed using scanning electron microscopy in reconstructed regions treated with EGF- and bFGF-supplemented collagen sponges. However, bFGF-supplemented collagen sponges led to greater microsphere transport than did EGF-supplemented sponges. The present data suggested that collagen sponge scaffold containing bFGF promotes functional regeneration of tracheal epithelial tissues.

Characterization of aged rat vocal fold fibroblasts.

OBJECTIVES/HYPOTHESIS: To elucidate the aging physiology of the vocal folds, we examined the characters of aged vocal fold fibroblasts (VFFs) in various conditions. STUDY DESIGN: In vitro study. METHODS: VFFs from young (12-week-old) and aged (19-month-old) Sprague-Dawley rats were compared. Proliferative capacity, ratio of myofibroblast to fibroblast, myofibroblast function, and extracellular matrix production were examined in the following conditions: naïve, basic fibroblast growth factor (bFGF) supplemented, and hepatocyte growth factor (HGF) supplemented. RESULTS: Aged VFFs demonstrated reduced proliferation by cell counting, though the ratio of Ki-67-positive cells showed no difference. Aged VFFs exhibited an increased expression of α-smooth muscle actin (α-SMA); however, they demonstrated no enhanced contractile ability in a gel contraction assay. Type I collagen protein was increased age dependently, accompanied with decreased Mmp1 and unchanged Col1a1 transcription. Type I collagen protein and α-SMA represented quite similar reduction patterns to bFGF or HGF administration. CONCLUSIONS: The following possible characteristics of aged VFFs were implied: long duration of mitosis, increased myofibroblast population size with certain dysfunctions, reduced type I collagen turnover, and correlation between α-SMA expression and type I collagen metabolism. Further investigations of these features will help to clarify presbyphonia's pathology and establish treatment strategies. LEVEL OF EVIDENCE: NA Laryngoscope, 129:E94-E101, 2019.