Recombinant tetra-cell adhesion motifs supports adhesion, migration and proliferation of keratinocytes/fibroblasts, and promotes wound healing

An extracellular matrix protein plays an important role in skin wound healing. In the present study, we engineered a recombinant protein encompassing the 9th and 10th type III domains of fibronectin, and 4th FAS1 domain of beta ig-h3. This recombinant protein, in total, harbors four known-cell adhesion motifs for integrins: Pro-His-Ser-Arg-Asn (PHSRN) and Arg-Gly-Asp (RGD) in 9th and 10th type III domains of fibronectin, respectively, and Glu-Pro-Asp-Ile-Met (EPDIM) and Try-His (YH) in 4th FAS1 domain of big-h3, were designated to tetra-cell adhesion motifs (T-CAM). In vitro studies showed T-CAM supporting adhesion, migration and proliferation of different cell types including keratinocytes and fibroblasts. In an animal model of full-thickness skin wound, T-CAM exhibited excellent wound healing effects, superior to both 4th FAS1 domain of beta ig-h3 or 9th and 10th type III domains of fibronectin. Based on these results, T-CAM can be applied where enhancement of cell adhesion, migration and proliferation are desired, and it could be developed into novel wound healing drug.

Reconstruction of Soft Tissue Defect on Distal Leg with Extensor Digitorum Brevis Myo-Cutaneous Flap

PURPOSE: To report of a series of successful reconstruction of soft tissue defect on distal leg with extensor digitorum brevis myo-cutaneous flap. METHODS: Between April 2002 to December 2004, 7 patients with soft tissue defect on distal leg were operated with Extensor Digiotorum Brevis myocutaneous flap. 6 of these patients had osteomyelitis. RESULTS: Extensor Digiotorum Brevis myocutaneous flap were used in 6 patients and reverse flow flap was used in one patient. Average follow up was 19 months. All flap were survived 100% without any complication and osteomyelitis were controled in all cases. Aesthetic and functional out come were excellent on both recipient and donor sites. CONCLUSION: The advantages of this flap are effectively control of local wound infection, constant and reliable anatomical structures, adequately thin flap. Technical easiness for raising flap and wide arch of rotation. Extensor Digitorum Brevis myo-cutaneous flap is one of ideal option for the reconstruction of distal leg and foot defects.

Proper Condition of Centrifugation for the Fat Cell Viability in the Autologous Fat Injection

PURPOSE: In the autologous fat injection, the centrifugation is useful for the refinement of harvested fat. As it can be an injury to the fat cell, we studied the fat cell viability with the change of centrifugation velocity and centrifugation time in order to get the limits of centrifugation velocity and centrifugation time. METHODS: We used the Colman System in 8 patients. We handled the control group with no centrifugation, group I with the centrifugation with 1500rpm for 1 minute, group II with 1500 rpm for 3 minutes, group III with 1500rpm for 5 minutes, group IV with 3000rpm for 1 minute, group V with 3000rpm for 3 minutes, group VI with 3000rpm for 5 minutes, group VII with 5000rpm for 1 minute, group VIII with 5000rpm for 3 minutes, group IX with 5000rpm for 5 minutes. We used the collagenase to separate the fat tissue. We had evaluated the fat cell viability by checking survival cell counts. RESULTS: There was no significance in group I, II, IV, V, but there was significant difference in group III, VI, VII, VIII, IX. CONCLUSION: The centrifugation with 3000rpm for 3 minutes is recommendable.

A Case of Primary Mucinous Eccrine Carcinoma in the Lower Eyelid Skin

Primary mucinous eccrine carcinoma(MEC) of the skin, one of sweat gland tumor, is a rare. These tumors usually occur in one's fifties and seventies, and are characterized by the secretion of mucin that usually forms the pools surrounding the clusters of tumor cells. The common sites are the eyelids and medial canthus. Pathologically it is difficult to distinguish between primary mucionus carcinoma and metastatic cancers from breast, rectum, colon, bronchus, kidney, ovary, stomach, lacrimal glands, salivary glands, and paranasal sinuses. Therefore study for primary focus is needed. A 62-year-old mand has had a mass on left lower eyelid skin without palpable neck lymph nodes for about five years. In a fine needle aspiration, there were tumor cells floating in a mucin pool. The authors examined several tests including complete blood cell count, liver function test, renal function test, urinalysis, electrocardiography, VDRL, TPHA-S, chest X-ray, chest computed tomography(CT), neck CT, abdominopelvic CT, etc. All the tests showed the origin was the skin. It is diagnosed to primary MEC on skin. The tumor was treated by wide excision with 0.5cm in safe margin and full thickness skin graft was done. There has been no recurrence 10 months after operation.

The Bone Regenerative Effect of Calcium Sulfate- chitosan Complex Powder and Chitosan Microsphere Encapsulating Growth Hormone on Bone Formation in Bone Defect of Rabbits

This study was carried out on 32 New Zealand white rabbits, each weighing 3-3.5kg. Eight rabbits were allocated into each of four groups. The groups were a control group(I), hyaluronic acid group(II), chitosan microsphere encapsulating growth hormone group(III), calcium sulfate-chitosan powder group(IV). After a 1cm sized ostectomy was made on the tibial body with the periosteum preserved, artificial bone substitutes were implanted. Except group I, 1ml of hyaluronic acid were implanted in group II, 1ml of chitosan microsphere encapsulating growth hormone in group III, 1ml of manufactured calcium sulfate-chitosan complex powder in group IV. Results were evaluated using radiographic study every week, bone mineral density test and histologic examination at 2, 4, 6 weeks and three point bending test at 6 weeks after implantation. In the radiographic study, the formation and corticalization of callus were seen similarly in group III, IV and much more and earlier than group I, II. In the bone mineral density test and three point bending test to contralateral normal tibia in 6 weeks, the values in groups III and IV were statistically significantly higher than in group I and II(p<0.05). In histologic examination, group III and IV have more abundant and faster new boner formation than group I and II. In conclusion, calcium sulfate-chitosan complex powder and chitosan microsphere encapsulating growth hormone facilitates the formation of new bone. They will be used effectively as a bone substitute on defected bone in clinical situations.

The Comparative Study between PLGA and Chitosan Scaffolds for Cartilage Tissue Engineering

Clinical application of the cartilage formed by tissue engineering is of no practical use due to the failure of long-term structural integrity maintenance. One of the important factors for integrity maintenance is the biomaterial for a scaffold. The purpose of this study is to evaluate the difference between polylactic-co-glycolic acids (PLGA) and chitosan as scaffolds. Human auricular chondrocytes were isolated, cultured, and seeded on the scaffolds, which were implanted in the back of nude mice. Eight animals were sacrificed at 4, 8, 12, 16, and 24 weeks after implantation respectively. In gross examination and histological findings, the volume of chondrocyte-PLGA complexes was decreased rapidly. The volume of chondrocyte-chitosan complexes was well maintained with a slow decrease rate. The expression of type II collagen protein detected by immunohistochemistry and western blots became weaker with time in the chondrocyte-PLGA complexes. However, the expression in the chondrocyte-chitosan complexes was strong for the whole period. Collagen type II gene expressions using RT-PCR showed a similar pattern. In conclusion, these results suggest that chitosan is a superior scaffold in cartilage tissue engineering in terms of structural integrity maintenance. It is expected that chitosan scaffold may become one of the most useful scaffolds for cartilage tissue engineering.