Collagen Sheet Research Articles

コラーゲンシートに対する間葉系幹細胞の浸潤促進技術の確立

コラーゲンシートに対する間葉系幹細胞の浸潤促進技術の確立

A Comparative Study of Collagen Dressing versus Petrolatum Gauze Dressing in reducing Pain at the Donor Area.

Background:Skin graft is one of the commonly done procedures by plastic surgeons, dermato surgeons and general surgeons. Pain at the donor area is a common complaint by the patient. The skin graft donor site area is usually covered with petrolatum dressing dermatosurgeons.Aim:This study was done to compare collagen dressing with petroleum gauze dressing in control of post-operative pain on skin graft donor area.Materials and Methods:The study was done on forty patients, twenty as study group who received collagen dressing and twenty as control group who received petroleum gauze dressing. The procedure was randomly selected by permutated block size of four. The post-operative pain was assessed with numerical pain rating scale 0 to 10. Nursing staff did the recording of pain scale. The nursing staff was not aware whether patient had collagen or petroleum gauze dressing.Statistics:Statistical analysis used was independent ‘t’-test (two-sample test) and Levene's test.Results:Statistics proved that study group (collagen dressing) had lesser pain than control group (petroleum gauze dressing).Conclusion:The collagen sheet dressing on skin graft donor area reduces pain in post-operative period.

Optimizing cell sourcing for clinical translation of tissue engineered ears**Portions of this research were presented at The New York Regional Society of Plastic Surgery Annual Meeting (March 2015, New York, NY), The American Association of Plastic Surgeons 94th Annual Meeting (April 2015, Scottsdale, AZ), The 60th Annual Meeting of the Plastic Surgery Research Council (May 2015, Seattle, WA), and the

Background. Currently, the major impediment to clinical translation of our previously described platform for the fabrication of high fidelity, patient-specific tissue engineered ears is the development of a clinically optimal cell sourcing strategy. A limited autologous auricular chondrocyte (AuC) supply in conjunction with rapid chondrocyte de-differentiation during in vitro expansion currently makes clinical translation more challenging. Mesenchymal stem cells (MSCs) offer significant promise due to their inherent chondrogenic potential, and large availability through minimally invasive procedures. Herein, we demonstrate the promise of AuC/MSC co-culture to fabricate elastic cartilage using 50% fewer AuC than standard approaches. Methods. Bovine auricular chondrocytes (bAuC) and bovine MSC (bMSC) were encapsulated within 10 mg ml−1 type I collagen hydrogels in ratios of bAuC:bMSC 100:0, 50:50, and 0:100 at a density of 25 million cells ml−1 hydrogel. One mm thick collagen sheet gels were fabricated, and thereafter, 8 mm diameter discs were extracted using a biopsy punch. Discs were implanted subcutaneously in the dorsa of nude mice (NU/NU) and harvested after 1 and 3 months. Results. Gross analysis of explanted discs revealed bAuC:bMSC co-culture discs maintained their size and shape, and exhibited native auricular cartilage-like elasticity after 1 and 3 months of implantation. Co-culture discs developed into auricular cartilage, with viable chondrocytes within lacunae, copious proteoglycan and elastic fiber deposition, and a distinct perichondrial layer. Biochemical analysis confirmed that co-culture discs deposited critical cartilage molecular components more readily than did both bAuC and bMSC discs after 1 and 3 months, and proteoglycan content significantly increased between 1 and 3 months. Conclusion. We have successfully demonstrated an innovative cell sourcing strategy that facilitates our efforts to achieve clinical translation of our high fidelity, patient-specific ears for auricular reconstruction utilizing only half of the requisite auricular chondrocytes to fabricate mature elastic cartilage.

Recurrent laryngeal nerve regeneration using an oriented collagen scaffold containing Schwann cells.

Regeneration of the recurrent laryngeal nerve (RLN), which innervates the intrinsic laryngeal muscles such that they can perform complex functions, is particularly difficult to achieve. Synkinesis after RLN neogenesis leads to uncoordinated movement of laryngeal muscles. Recently, some basic research studies have used cultured Schwann cells (SCs) to repair peripheral nerve injuries. This study aimed to regenerate the RLN using an oriented collagen scaffold containing cultured SCs. Preliminary animal experiment. A 10-mm-long autologous canine cervical ansa was harvested. The nerve tissue was scattered and subcultured on oriented collagen sheets in reduced serum medium. After verifying that the smaller cultivated cells with high nucleus-cytoplasm ratios were SCs, collagen sheets with longitudinally oriented cells were rolled and inserted into a 20-mm collagen conduit. The fabricated scaffolds containing SCs were autotransplanted to a 20-mm deficient RLN, and vocal fold movements and histological characteristics were observed. Scaffolds containing cultured SCs were successfully fabricated. Immunocytochemical examination revealed that these isolated and cultured cells, identified as SCs, expressed S-100 protein and GFAP but not vimentin. The orientation of SCs matched that of the oriented collagen sheet. Two months after successful transplantation, laryngeal endoscopy revealed coordinated movement of the bilateral vocal folds by external stimulation under light general anesthesia. Hematoxylin and eosin staining showed that the regenerated RLN lacked epineurium surrounding the nerve fibers and was interspersed with collagen fibers. Myelin protein zero was expressed around many axons. Partial regeneration of RLN was achieved through the use of oriented collagen scaffolding. NA Laryngoscope, 127:1622-1627, 2017.

Stretching human mesenchymal stromal cells on stiffness-customized collagen type I generates a smooth muscle marker profile without growth factor addition.

Using matrix elasticity and cyclic stretch have been investigated for inducing mesenchymal stromal cell (MSC) differentiation towards the smooth muscle cell (SMC) lineage but not in combination. We hypothesized that combining lineage-specific stiffness with cyclic stretch would result in a significantly increased expression of SMC markers, compared to non-stretched controls. First, we generated dense collagen type I sheets by mechanically compressing collagen hydrogels. Atomic force microscopy revealed a nanoscale stiffness range known to support myogenic differentiation. Further characterization revealed viscoelasticity and stable biomechanical properties under cyclic stretch with >99% viable adherent human MSC. MSCs on collagen sheets demonstrated a significantly increased mRNA but not protein expression of SMC markers, compared to on culture flasks. However, cyclic stretch of MSCs on collagen sheets significantly increased both mRNA and protein expression of α-smooth muscle actin, transgelin, and calponin versus plastic and non-stretched sheets. Thus, lineage-specific stiffness and cyclic stretch can be applied together for inducing MSC differentiation towards SMCs without the addition of recombinant growth factors or other soluble factors. This represents a novel stimulation method for modulating the phenotype of MSCs towards SMCs that could easily be incorporated into currently available methodologies to obtain a more targeted control of MSC phenotype.

Fabrication of Ca2+-K+ Image Sensor Using an Inkjet Method and Its Application to Living Cells

Introduction It is extremely important to know the change in the ion concentration in order to understand the dynamics of living cells. Nowadays, considerable attention has been paid to the method which can display ion concentration intuitively. In our laboratory, we have developed several ion image sensors by modifying a CCD-type pH image sensor with plasticized poly(vinyl chloride) (PVC) membranes. Recently, Na+-K+ image sensor [1] was fabricated using a inkjet method. In this paper, we developed Ca2+-K+ image sensor. Ca2+ and K+are very important ions in cells. Cell membranes have each ion channel and each ion pump. Both of ions exist on lower concentration in extracellular fluid than in cells. Materials and methods The half of a CCD-type pH image sensor was modified with Ca2+ selective membrane using a inkjet method. Similarly, the other half was modified with K+ selective membrane. The K+ selective membrane was prepared in our previous paper [1].The inkjet condition of the Ca2+ selective membrane was optimized, and the membrane with Nernstian response was prepared. The K+ selective membrane consisted of 30.0 % of PVC (MW = 82000), 30.0 % of 1,3,5,7,9,11,13,15-octa(propylmethacryl)pentacyclo[9.5.1.13,9.15,15.17,13]octasiloxane (POSS), 36.0 % of dioctyl sebacate (DOS), 2.7 % of valinomycin, and 1.3 % of potassium tetrakis (4-chlorophenyl)borate (K-TCPB). Ca2+ selective membrane consisted of 30.0 % of PVC, 10.0 % of POSS, 55.0 % of 2-nitrophenyl octyl ether (NPOE), 3.6 % of 10,19-bis[(octadecylcarbamoyl)methoxyacetyl]-1,4,7,13,16-pentaoxa-10,19-diazacycloheneicosane (K23E1) and 1.4 % of sodium tetrakis[3,5-bis(trifluoromethyl)phenyl]borate (Na-TFPB). Real-time bio-images for PC12 cells (rat pheochromocytoma cell line) and Hela cells (human cervical cancer cell line) were captured by the Ca2+-K+image sensor. Results and Discussion After several days culture of PC12 cells on the collagen sheet, the cells on the Ca2+-K+ image sensor were stimulated by acetylcholine (Ach). As a result, the Ca2+ concentration decreased after the stimulation. On the other hand, there was no significant change in K+ concentration. The previous study [2] reported that the stimulation brought about the decrease in the Ca2+ concentration. This study confirmed that the decrease of Ca2+ wasn’t accompanied by the change in the K+concentration. After a day culture of HeLa cells, the cells were stimulated by Amphotericin B. As a result, the K+ concentration increased after the stimulation. Meanwhile, there was no significant change in Ca2+ concentration. A related result that showed the Amphotericin B-induced decreasing of K+ concentration in HeLa cells due to the K+ efflux was reported by Ohtsuka et al. [3] through the fluorometric imaging. The present study indicated that the change can be recorded only in the K+concentration with a non-invasive and easy method. In conclusion, the Ca2+-K+image sensor demonstrated successfully the real-time monitoring of living cells stimulated. [1]T. Hattori, H. Sato, K. Tokunaga, R. Kato, K. Sawada, Sensors and Materials, 27, (2015) ,1023-1034 [2] H. Taki, T. Sakurai, Y. Masaki, T. Hattori, K. Takahashi, S. Terakawa, M. Ishida, K. Okumura, K. Sawada, 2012 International Symposium on Chemical-Environmental-Biomedhical Technology, P_BE1_09, September 2-5, Tainan, Taiwan (2012) [3]K. Ohtsuka, S. Sato, Y. Sato, K. Sota, S. Ohzawa, T. Matsuda, K. Takemoto , N. Takamune, B. Juskowiak, T. Nagai, S. Takenaka, Chem. Commun., 48, (2012), 4740-4742

Orbital reconstruction in the dog, cat, and horse.

To describe an adaptable method for reconstruction of the orbit following partial orbitectomy. One horse, one cat, and four dogs. Following partial orbitectomy for removal of bone and soft tissue affected by pathologic processes, reconstruction was achieved. Cerclage wires were used to reconstitute the orbital rim and other salient facial contours involved in excisions. These wires were then covered with a prolene mesh, first inside the orbit and then outwards over the affected extraorbital areas. Thereafter, a collagen sheet was placed over the mesh. Finally, subcutis and skin were closed over the construct. All operated eyes remained visual with normal position, direction, and mobility. Eyelid function, tear production, and nasolacrimal function were preserved. Side effects were mild and temporary, but animals requiring a lateral-posterior surgical approach experienced concavity to the side of the head posterior to the orbital ligament region. One bone tumor out of three recurred. The reconstruction method presented offers excellent results tectonically, cosmetically, and functionally, even following extensive orbitectomy. By adapted application of three reconstruction steps using readily available materials, large defects may be surgically repaired. Once orbitectomy is mastered, reconstruction requires no additional specialized techniques or equipment.

Management of osteonecrosis of the femoral head: A novel technique.

Background:Osteonecrosis of the femoral head (ONFH) is a debilitating disease in orthopedics, frequently progressing to femoral head collapse and osteoarthritis. It is thought to be a multifactorial disease. ONFH ultimately results in femoral head collapse in 75–85% of untreated patients. Total hip arthroplasty (THA) yields satisfactory results in the treatment of the end stage of the disease. However, disease typically affects males between the ages of 20 and 40 years and joint replacement is not the ideal option for younger patients. Recently, mesenchymal stem cells and platelet rich plasma (PRP) have been used as an adjunct to core decompression to improve clinical success in the treatment of precollapse hips.Materials and Methods:A prospective study of 40 hips in 30 patients was done. There were 19 males and 11 females with a mean age 36.7 ± 6.93 years. The indication for the operation was restricted primarily to modified Ficat stages IIb and III. 16 hips (40%) had stage IIb and 24 hips (60%) had stage III ONFH. The period of follow up ranged between 36–50 months with a mean 41.4 ± 3.53 months. All patients were assessed clinically during pre- and post-operative period according to the Harris Hip Score (HHS), Visual Analog Score (VAS) and radiologically by X-rays. Magnetic resonance imaging (MRI) was done preoperatively to confirm the diagnosis and every 6 months postoperatively for assessment of healing. The operative procedure include removal of necrotic area with drilling then the cavity was filled with a composite of bone graft mixed with PRP.Results:The mean HHS improved from 46.0 ± 7.8 preoperatively to 90.28 ± 19 at the end of followup (P < 0.0001). The mean values of VAS were 78 ± 21 and 35 ± 19 at preoperatively period and final followup, respectively, with an average reduction of 43 points.Conclusion:We found that the use of PRP with collagen sheet can increase the reparable capacity after drilling of necrotic segment in stage IIb and III ONFH.

Novel three-dimensional autologous tissue-engineered vaginal tissues using the self-assembly technique

Many diseases necessitate the substitution of vaginal tissues. Current replacement therapies are associated with many complications. In this study, we aimed to create bioengineered neovaginas with the self-assembly technique using autologous vaginal epithelial (VE) and vaginal stromal (VS) cells without the use of exogenous materials and to document the survival and incorporation of these grafts into the tissues of nude female mice. Epithelial and stromal cells were isolated from vaginal biopsies. Stromal cells were driven to form collagen sheets, 3 of which were superimposed to form vaginal stromas. VE cells were seeded on top of these stromas and allowed to mature in an air-liquid interface. The vaginal equivalents were implanted subcutaneously in female nude mice, which were sacrificed after 1 and 2weeks after surgery. The invitro and animal-retrieved equivalents were assessed using histologic, functional, and mechanical evaluations. Vaginal equivalents could be handled easily. VE cells formed a well-differentiated epithelial layer with a continuous basement membrane. The equivalent matrix was composed of collagen I and III and elastin. The epithelium, basement membrane, and stroma were comparable to those of native vaginal tissues. The implanted equivalents formed mature vaginal epithelium and matrix that were integrated into the mice tissues. Using the self-assembly technique, invitro vaginal tissues were created with manyfunctional and biological similarities to native vagina without any foreignmaterial. They formed functional vaginal tissues after invivo animal implantation. Itis appropriate for vaginal substitution and disease modeling for infectious studies,vaginal applicants, and drug testing.

Collagen Substrate Stiffness Anisotropy Affects Cellular Elongation, Nuclear Shape, and Stem Cell Fate toward Anisotropic Tissue Lineage.

Rigidity of substrates plays an important role in stem cell fate. Studies are commonly carried out on isotropically stiff substrate or substrates with unidirectional stiffness gradients. However, many native tissues are anisotropically stiff and it is unknown whether controlled presentation of stiff and compliant material axes on the same substrate governs cytoskeletal and nuclear morphology, as well as stem cell differentiation. In this study, electrocompacted collagen sheets are stretched to varying degrees to tune the stiffness anisotropy (SA) in the range of 1 to 8, resulting in stiff and compliant material axes orthogonal to each other. The cytoskeletal aspect ratio increased with increasing SA by about fourfold. Such elongation was absent on cellulose acetate replicas of aligned collagen surfaces indicating that the elongation was not driven by surface topography. Mesenchymal stem cells (MSCs) seeded on varying anisotropy sheets displayed a dose-dependent upregulation of tendon-related markers such as Mohawk and Scleraxis. After 21 d of culture, highly anisotropic sheets induced greater levels of production of type-I, type-III collagen, and thrombospondin-4. Therefore, SA has direct effects on MSC differentiation. These findings may also have ramifications of stem cell fate on other anisotropically stiff tissues, such as skeletal/cardiac muscles, ligaments, and bone.

Photo-immobilization of bone morphogenetic protein-2 using azidophenyl gelatin on a collagen sheet enhances osteogenesis in a rat calvarial defect model

Twenty-eight rats were randomized into two groups: a control group comprising a collagen sheet with only cast BMP-2; and an experimental group comprising a collagen sheet with BMP-2 photo-immobilized using azidophenyl gelatin. Micro-computed tomography analysis revealed that there was more regenerated bone in experimental group at both 4 and 8 weeks. Immunohistochemical analysis revealed that the positively expressed cellular ratio in RUNX2-stained cells were significantly higher in experimental group. These results demonstrate that BMP-2 photo-immobilized using Az-Gel on a collagen sheet shows promising bone regeneration, and the sheet is a good candidate of BMP-2 carrier.

IGF-1-containing multi-layered collagen-fibrin hybrid scaffolds for bladder tissue engineering

Clinical success of bladder reconstructive procedures could be promoted by the availability of functional biomaterials. In this study, we have developed a multi-layered scaffold consisting of a bioactive fibrin layer laminated between two collagen sheets all having undergone plastic compression. With this construct we performed bladder augmentation in a nude rat model after partial bladder excision and evaluated the morphological and functional behavior of the implant. The fibrin was functionalized with a recombinant human insulin-like growth factor-1 (IGF-1) variant that covalently binds fibrin during polymerization and has a matrix metalloproteinase-cleavage insert to enable cell-mediated release. The purified IGF-1 variant showed similar bioactivity in vitro compared to commercially available wild type (wt) IGF-1, inducing receptor phosphorylation and induction of human smooth muscle cell proliferation. In vivo, the multi-layered bioactive collagen-fibrin scaffolds loaded with the IGF-1 variant triggered dose-dependent functional host smooth muscle cell invasion and bundle formation with re-urothelialization 4weeks after surgery in a rat model. Statement of SignificanceThe design of new bio-functional scaffolds that can be employed for bladder reconstructive procedures is a growing focus in the field of tissue engineering. In this study, a fibrin binding form of human insulin-like growth factor-1 (IGF-1) was produced and used to functionalize a multi-layered collagen-fibrin scaffold consisting of bioactive fibrin layer, sandwiched between two collagen gels. An effective dosage of our IGF-1 variant was successfully determined via a nude rat bladder model, which may play a critical role in estimating its therapeutic dosage in clinical trials. Thus, this new bioactive scaffold may offer an advanced approach to accelerate bladder regeneration.

Vitreous anatomy and the vitreomacular correlation.

The presence of a posterior precortical vitreous pocket, referred to as a precortical pocket, implies that the vitreous cortex is formed into a collagen sheet separated from the gel in the macula. Along with strong vitreoretinal attachment at the fovea, the precortical pocket plays a role in perifoveal posterior vitreous detachments, which may lead to macular holes, premacular membranes, and ring-shaped proliferation in diabetic retinopathy. I and my colleagues published pioneer studies of the vitreous in postmortem eyes. Here, the role of the precortical pocket in various vitreoretinal interface diseases is discussed. Swept-source optical coherence tomography showed development of the precortical pocket, the connecting channel, and Cloquet's canal during early childhood. These findings raised the possibility that aqueous humor may drain into the precortical pocket. The physiologic role of the drainage route is also discussed. Crosstalk between the anterior chamber and macula is an attractive hypothesis and remains to be elucidated.

Formation of Highly Aligned Collagen Nanofibers by Continuous Cyclic Stretch of a Collagen Hydrogel Sheet.

A collagen sheet with highly aligned collagen fibers is fabricated by continuous cyclic stretch. The rearrangement of the collagen fibers depends on the different process parameters of the cyclic stretch, including magnitude, frequency, and period of stretch. The collagen fibers are aligned perpendicularly to the direction of the stretch. Corneal stromal cells and smooth muscle cells cultivated on the highly aligned collagen sheet show alignment along the collagen fibers without the stretch during culture. Thus, the sheet can be a suitable scaffold for use in regenerative medicine.

A biological study establishing the endotoxin limit of biomaterials for bone regeneration in cranial and femoral implantation of rats.

The purpose of this study was to accurately quantify the risk of endotoxin contamination in biomaterials for bone regeneration in order to establish the acceptable endotoxin limit. Collagen sheets containing varying amounts of purified endotoxin from Escherichia coli and dried, heat-killed E. coli or Staphylococcus aureus cells were implanted into cranial or femoral defects in rats. These defects were artificially prepared to a size of 5 × 5 mm or a diameter of 1 mm, respectively. The degree of osteoanagenesis was assessed by soft X-ray radiography and histopathology at 1 and 4 weeks after implantation. The collagen sheet containing the dried E. coli cells showed a dose-dependent delay in cranial and/or femoral osteoanagenesis at endotoxin activities of more than 33.6 EU/mg, at which no inflammatory response was observed. In contrast, no such observation occurred with the collagen sheet containing S. aureus cells. These results suggest that endotoxins may affect the process of osteoanagenesis. Additionally, the no-observed-adverse-effect level was 9.6 EU/mg, corresponding to 255 EU/kg body weight in rats. Interestingly, no delay in osteoanagenesis was induced by the implantation of collagen sheets containing purified endotoxin at any dose tested. This suggested that pure endotoxin implanted into tissues having poor circulation of bodily fluids without bleeding may not be recognized as a foreign substance and may not induce a significant biological response. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 1514-1524, 2017.

Bovine reticulum derived extracellular matrix (b-REM) for reconstruction of full thickness skin wounds in rats

Abstract Thirty six clinically healthy adult Wistar rats of either sex were used in the study and randomly divided into three groups having twelve animals in each group. Under general anesthesia, a full-thickness skin wound (20 × 20 mm2) was created on the dorsum of each rat. The defect in group I was kept as open wound and was taken as control. In group II, the defect was repaired with commercially available collagen sheet (b-CS). In group III, the defect was repaired with reticulum derived extracellular matrix of bovine origin (b-REM). Healing was evaluated on the basis of wound contraction, gross, haematological, immunological and histopathological observations. On critical analysis of the observed parameters it was found that b-REM has healing potential and shown better healing response than commercially available collagen sheet to reconstruct full thickness skin wounds in rats.

Preventive Measures for Postoperative Bile Leakage After Central Hepatectomy: A Multicenter, Prospective, Observational Study of 101 Patients.

There are no conclusive measures for preventing postoperative bile leakage (POBL). First, 310 patients who underwent hepatectomy were analyzed retrospectively to clarify risk factors for POBL. Then, focusing on operations at high risk of POBL, patients who underwent central hepatectomy were recruited prospectively among 18 institutions, to evaluate various preventive measures for avoiding POBL. The primary endpoint was the frequency of POBL. The retrospective analysis revealed central hepatectomy and repeated hepatectomy to be independent risk factors for POBL. One hundred and one patients undergoing central hepatectomy were enrolled in the prospective study.POBL developed in 13 patients (12.9%). Intraoperative bile leakage was recognized in 42 of the 101 patients (41.6%), and 10 of the 42 patients developed POBL (23.8%). Primary closure of the site of bile leakage and/or biliary drainage tube placement was preferable for preventing POBL in the patients with intraoperative bile leakage. Although 59 patients (58.4%) did not show intraoperative bile leakage, three patients (5.1%) developed POBL. In the group without intraoperative bile leakage, treatment with fibrin glue with a polyglycolic acid (PGA) sheet or collagen sheet coated with a fibrinogen and thrombin layer (CSFT) had good results. Primary closure of the site of bile leakage and/or placement of biliary drainage tubes may be recommended in cases involving intraoperative bile leakage. Treatment with fibrin glue with a PGA sheet and/or CSFT might have preventive effects in patients without intraoperative bile leakage.

Reactive Soft Tissue Preservation in Large Bone Defects After Tooth Extractions: A Cone Beam Study.

Reduction of alveolar height and width after tooth extraction may present problems for implant placement, since bone volume is important for biologic and esthetic reasons. The aim of this study was to assess bone healing of large bone defects grafted with collagen sheets and maintenance of reactive soft tissue, evaluating cone beam computed tomography (CBCT) scans and histomorphometric results. Patients presented large bone defects after tooth extractions. Reactive soft tissue was left in the defects filled by collagen sheets. Vertical bone volume was assessed by CBCT examinations before tooth extractions and 3 months later. At 3 months, cylinder bone samples were obtained for histology and histomorphometry analysis. Twenty-six patients were included in the clinical study. Examined defects reported mean bone gain of 12.13 ± 3.91 mm, and mean vertical bone levels showed a statistically significant increase (P < .05) at 3 months after extraction. Histologic examinations revealed bone formation; mean vital bone measurements were 41.59% ± 5.80%, and connective tissue percentages averaged 50.37% ± 7.73%. Reactive soft tissue left in large bone defects after tooth extraction and grafted collagen may support a significant vertical bone gain and vital bone formation.

コラーゲンシートを用いた培養筋芽細胞の配向性評価

In this study to develop a bio-actuator using C2C12 cells, we propose to align the orientations of the cells using a collagen sheet. A cell was seeded and cultivated to an orientation collagen sheet, rounding that half of the cultivated cell had the same orientation which showed the collagen sheet to control the orientation of the C2C12 cells.

Bubaline Cholecyst Derived Extracellular Matrix for Reconstruction of Full Thickness Skin Wounds in Rats.

An acellular cholecyst derived extracellular matrix (b-CEM) of bubaline origin was prepared using anionic biological detergent. Healing potential of b-CEM was compared with commercially available collagen sheet (b-CS) and open wound (C) in full thickness skin wounds in rats. Thirty-six clinically healthy adult Sprague Dawley rats of either sex were randomly divided into three equal groups. Under general anesthesia, a full thickness skin wound (20 × 20 mm2) was created on the dorsum of each rat. The defect in group I was kept as open wound and was taken as control. In group II, the defect was repaired with commercially available collagen sheet (b-CS). In group III, the defect was repaired with cholecyst derived extracellular matrix of bovine origin (b-CEM). Planimetry, wound contracture, and immunological and histological observations were carried out to evaluate healing process. Significantly (P < 0.05) increased wound contraction was observed in b-CEM (III) as compared to control (I) and b-CS (II) on day 21. Histologically, improved epithelization, neovascularization, fibroplasia, and best arranged collagen fibers were observed in b-CEM (III) as early as on postimplantation day 21. These findings indicate that b-CEM have potential for biomedical applications for full thickness skin wound repair in rats.