Suk Wha Kim

Fibroblasts and ascorbate regulate epidermalization in reconstructed human epidermis

Skin equivalent model provides a new investigating system to study the role of extracellular matrix and dermal factors such as collagen, basement membrane components and fibroblasts (Fb) which contribute to cell-cell and cell-matrix interactions. Although basement membrane factors is known to play an important role in epidermal differentiation and epidermal-matrix adhesion, comparative effects of these extracellular matrix and dermal factors on the reconstruction of epidermis are little known. In this study, we investigated effects of type I collagen (Coll I), type IV collagen plus laminin (LAM) coated Coll I (Coll IV+LAM), and human Fb enriched Coll I (Coll I+Fb) on epidermal reconstruction. When human keratinocytes were cultured on three different gels containing Coll I, Coll IV+LAM and Coll I+Fb, basal keratinocytes were cuboidal and perpendicular to the dermo-epidermal junction only in the gel containing Coll I+Fb. Proliferation marker expression was prominent and differentiation marker expression was similar with those of normal skin in the gel containing Coll I+Fb than in the other gel models. Since ascorbate is suspected to exert an effect as a modulator of proliferation and differentiation in keratinocytes, we tested the effects of ascorbate on human epidermis reconstruction. When 25 microg/ml ascorbate was added, disordered arrangement of epidermis was disappeared and differentiation marker expression was similar with its expression in normal skin. These data indicate that human Fb and a modulator of proliferation and differentiation such as ascorbate are essential for epidermalization in reconstructed epidermis.

Strong and Biostable Hyaluronic Acid–Calcium Phosphate Nanocomposite Hydrogel via in Situ Precipitation Process

Hyaluronic acid (HAc) hydrogel exhibits excellent biocompatibility, but it has limited biomedical application due to its poor biomechanical properties as well as too-fast enzymatic degradation. In this study, we have developed an in situ precipitation process for the fabrication of a HAc-calcium phosphate nanocomposite hydrogel, after the formation of the glycidyl methacrylate-conjugated HAc (GMHA) hydrogels via photo-cross-linking, to improve the mechanical and biological properties under physiological conditions. In particular, our process facilitates the rapid incorporation of calcium phosphate (CaP) nanoparticles of uniform size and with minimal agglomeration into a polymer matrix, homogeneously. Compared with pure HAc, the nanocomposite hydrogels exhibit improved mechanical behavior. Specifically, the shear modulus is improved by a factor of 4. The biostability of the nanocomposite hydrogel was also significantly improved compared with that of pure HAc hydrogels under both in vitro and in vivo conditions.

Three-Dimensional Pre-Bent Titanium Implant for Concomitant Orbital Floor and Medial Wall Fractures in an East Asian Population

Background The objective of this article is to evaluate clinical outcomes of combined orbital floor and medial wall fracture repair using a three-dimensional pre-bent titanium implant in an East Asian population. Methods Clinical and radiologic data were analyzed for 11 patients with concomitant orbital floor and medial wall fractures. A combined transcaruncular and inferior fornix approach with lateral canthotomy was used for the exposure of fractures. An appropriate three-dimensional preformed titanium implant was selected and inserted according to the characteristics of a given defect. Results Follow-up time ranged from 2 to 6 months (median, 4.07 months). All patients had a successful treatment outcome without any complications. Clinically significant enophthalmos was not observed after treatment. Conclusions Three-dimensional pre-bent titanium implants are appropriate for use in the East Asian population, with a high success rate of anatomic restoration of the orbital volume and prevention of enophthalmos in combined orbital floor and medial wall fracture cases.

Change in upper lip height and nostril sill after alveolar bone grafting in unilateral cleft lip alveolus patients

INTRODUCTION Alveolar bone grafting is known to reduce nasal asymmetry by supporting a defective alar base and a sunken nostril. However, there are no studies which include details of changes to the upper lip with appropriate measurements. The purpose of this study was to measure the change in the upper lip height and nostril sill after alveolar bone grafting, using photogrammetry. MATERIALS AND METHODS The study included 18 unilateral cleft lip alveolus (UCLA) patients who were diagnosed with unilateral cleft lip and palate (mean age, 9.87 years). The patients underwent alveolar bone grafting with iliac bone between June 2007 and June 2008. The average follow-up period was 16.6 months. The average bone graft volume was 2.39 cm(3). We obtained photographs of the frontal, lateral and basal views using standardised photographic techniques. We defined 14 landmarks and measured the distance of 11 points (distance items) for the determination of upper lip height, upper lip projection and nostril sill elevation. We defined the proportion index as the ratio of the cleft side to non-cleft side or reference line (R). We compared the preoperative proportion index with the postoperative proportion index for each distance items. RESULTS The height of the upper lip increased significantly in four of five distance items. The projection of the upper lip was more prominent, but it was not statistically significant. The nostril sill was significantly elevated in all four distance items. CONCLUSION The height of the upper lip was elongated and the nostril sill was elevated after alveolar bone grafting in UCLA patients.

Effects of collagen IV and laminin on the reconstruction of human oral mucosa

To investigate the effects of basement membrane proteins on the reconstruction of mucosa equivalent, oral mucosa substitute were cultured on (1) type I collagen gels, (2) type IV collagen-coated type I collagen gels, (3) laminin-coated type I collagen gels, and (4) type I collagen gels containing both type IV collagen and laminin. H/E and PAS staining showed that the characteristics of the oral mucosa were preserved under all the experimental conditions. However, the basal keratinocytes appeared cuboidal when the type I collagen gels were coated with type IV collagen plus laminin. The expression of the differentiation markers was similar, but weak staining of filaggrin, K13, and involucrin was observed with the type IV collagen plus laminin coating. Furthermore, electron microscopy revealed that the size of the basal keratinocytes was relatively small and uniform when both type IV collagen and laminin were used. These findings suggested that these two major basement membrane proteins are important in the process of differentiation in mucosal keratinocytes.

An anatomical study of the saphenous nerve, artery, and artery perforators within the thigh using cadaveric dissection.

Although the saphenous flap has been used in reconstruction as a free flap, there has not yet been an anatomic study about the perforators of the saphenous artery. The aim of this study is to investigate the anatomy of the saphenous artery and the number and locations of its perforators. We dissected parts of 10 legs from 5 cadavers. Measurements of the positions of the dissected saphenous arteries and their perforators were taken from the medial epicondyle of the femur. We observed the origin, end point, and the diameter of each of the arteries, and we investigated the numbers and locations of both septocutaneous and musculocutaneous perforators. The average length of saphenous artery was 14.8 cm, and it was located 12.0 cm above the medial epicondyle of the femur. The average diameter was 1.63 mm. A median average of 4 perforators branched out from a single saphenous artery. There was a median average of 2 septocutaneous perforators and 2 musculocutaneous perforators from the saphenous artery. The perforators were mainly located at 7 cm proximal to the medial epicondyle of the femur. The saphenous artery has many perforators and is therefore useful as the pedicle of the perforator flap. The saphenous artery perforator flap can be designed within 7 cm proximal to the medial epicondyle of the femur. Our results may be helpful in the applications of the neurocutaneous flap using the saphenous artery or the perforator flap based on septocutaneous perforators.

KCl Mediates K + Channel-Activated Mitogen-Activated Protein Kinases Signaling in Wound Healing

Background Wound healing is an interaction of a complex signaling cascade of cellular events, including inflammation, proliferation, and maturation. K+ channels modulate the mitogen-activated protein kinase (MAPK) signaling pathway. Here, we investigated whether K+ channel-activated MAPK signaling directs collagen synthesis and angiogenesis in wound healing. Methods The human skin fibroblast HS27 cell line was used to examine cell viability and collagen synthesis after potassium chloride (KCl) treatment by Cell Counting Kit-8 (CCK-8) and western blotting. To investigate whether K+ ion channels function upstream of MAPK signaling, thus affecting collagen synthesis and angiogenesis, we examined alteration of MAPK expression after treatment with KCl (channel inhibitor), NS1619 (channel activator), or kinase inhibitors. To research the effect of KCl on angiogenesis, angiogenesis-related proteins such as thrombospondin 1 (TSP1), anti-angiogenic factor, basic fibroblast growth factor (bFGF) and vascular endothelial growth factor (VEGF), pro-angiogenic factor were assayed by western blot. Results The viability of HS27 cells was not affected by 25 mM KCl. Collagen synthesis increased dependent on time and concentration of KCl exposure. The phosphorylations of MAPK proteins such as extracellular-signal-regulated kinase (ERK) and p38 increased about 2.5-3 fold in the KCl treatment cells and were inhibited by treatment of NS1619. TSP1 expression increased by 100%, bFGF expression decreased by 40%, and there is no significant differences in the VEGF level by KCl treatment, TSP1 was inhibited by NS1619 or kinase inhibitors. Conclusions Our results suggest that KCl may function as a therapeutic agent for wound healing in the skin through MAPK signaling mediated by the K+ ion channel.

Effect of Recombinant Human Bone Morphogenetic Protein-2 and Adipose Tissue-Derived Stem Cell on New Bone Formation in High-Speed Distraction Osteogenesis

Purpose The effects of recombinant human bone morphogenetic protein-2 (rhBMP-2) and osteogenically differentiated adipose tissue-derived stem cells (ADSC) on new bone formation in high-speed distraction osteogenesis of adult rabbit cranium were investigated. Materials and Methods A total of 41 adult rabbits were used in the study. Distraction began after a 5-day latency period at a rate of 1.5 mm twice a day until 10-mm length gain was obtained both in the control group, where a bone defect was induced, and in the experimental group, in which ADSC (group A), rhBMP-2 (group B), or both (group C) were injected in the distraction gap after distraction. At 4, 8, and 12 weeks after distraction, computed tomography analysis was done to determine the bone defect dimension and bone mineral density (BMD), while histologic examination was also done to calculate bone formation ratio. Results Bone defect dimension significantly decreased in groups B and C, compared with the control group, at 4 and 12 weeks after distraction. BMD was significantly increased in groups B and C at 4 weeks. On histologic examination, bone formation ratio was significantly increased in group C only at 12 weeks. Conclusion This study suggests that the use of rhBMP-2 in combination with or without ADSC is helpful to promote bone regeneration in high-speed distraction osteogenesi s of adult rabbit cranium.

Medial and lateral canthal reconstruction with an orbicularis oculi myocutaneous island flap.

Background The eyelid and canthal areas are common locations for cutaneous tumors. The medial canthus includes, among many other apparatuses, the canthal tendon and lacrimal canaliculi, and its characteristic thin and supple skin is hard to mimic and restore using tissue from other regions. Accordingly, reconstruction of the canthal area can prove challenging for surgeons. Although various methods, such as skin grafts and local flaps from adjacent regions, have been utilized for reconstructive purposes, they present known disadvantages. However, we were able to successfully reconstruct both lateral and medial canthal area defects by using orbicularis oculi myocutaneous island flaps. Methods Our study included seven patients who underwent medial or lateral canthal region reconstruction, using orbicularis oculi myocutaneous island flaps, between 2011 and 2014, following either cutaneous tumor excision or traumatic avulsion injury. Results Five patients had basal cell carcinoma, one had squamous cell carcinoma of the eyelid, and one had sustained a traumatic avulsion injury of the eyelid and canthal area. Entire flap loss was not observed in any patient, but one-a heavy smoker-showed partial flap loss, which healed with secondary intention and yielded acceptable results. Donor site morbidity was not observed, and all patients were satisfied with their surgical outcomes. Conclusions The canthal regions can be successfully reconstructed with orbicularis oculi myocutaneous island flaps. These flaps offer several key advantages, including similarity in texture, color, and thickness to the recipient site and a negligible incidence of donor site morbidity.

Acquired Palatal Fistula in Patients with Submucous and Incomplete Cleft Palate before Surgery

It is uncommon for a palatal fistula to be detected in individuals who have not undergone surgery, and only sporadic cases have been reported. It is even more difficult to find cases of acquired palatal fistula in patients with submucous or incomplete cleft palate. Herein, we present 2 rare cases of this phenomenon. Case 1 was a patient with submucous cleft palate who acquired a palatal fistula after suffering from oral candidiasis at the age of 5 months. Case 2 was a patient with incomplete cleft palate who spontaneously, without trauma or infection, presented with a palatal fistula at the age of 9 months.