Soh Nishimoto

Calcium-Based Nanoparticles Accelerate Skin Wound Healing

Introduction Nanoparticles (NPs) are small entities that consist of a hydroxyapatite core, which can bind ions, proteins, and other organic molecules from the surrounding environment. These small conglomerations can influence environmental calcium levels and have the potential to modulate calcium homeostasis in vivo. Nanoparticles have been associated with various calcium-mediated disease processes, such as atherosclerosis and kidney stone formation. We hypothesized that nanoparticles could have an effect on other calcium-regulated processes, such as wound healing. In the present study, we synthesized pH-sensitive calcium-based nanoparticles and investigated their ability to enhance cutaneous wound repair. Methods Different populations of nanoparticles were synthesized on collagen-coated plates under various growth conditions. Bilateral dorsal cutaneous wounds were made on 8-week-old female Balb/c mice. Nanoparticles were then either administered intravenously or applied topically to the wound bed. The rate of wound closure was quantified. Intravenously injected nanoparticles were tracked using a FLAG detection system. The effect of nanoparticles on fibroblast contraction and proliferation was assessed. Results A population of pH-sensitive calcium-based nanoparticles was identified. When intravenously administered, these nanoparticles acutely increased the rate of wound healing. Intravenously administered nanoparticles were localized to the wound site, as evidenced by FLAG staining. Nanoparticles increased fibroblast calcium uptake in vitro and caused contracture of a fibroblast populated collagen lattice in a dose-dependent manner. Nanoparticles also increased the rate of fibroblast proliferation. Conclusion Intravenously administered, calcium-based nanoparticles can acutely decrease open wound size via contracture. We hypothesize that their contraction effect is mediated by the release of ionized calcium into the wound bed, which occurs when the pH-sensitive nanoparticles disintegrate in the acidic wound microenvironment. This is the first study to demonstrate that calcium-based nanoparticles can have a therapeutic benefit, which has important implications for the treatment of wounds.

Effects of adiponectin on growth and differentiation of human keratinocytes--implication of impaired wound healing in diabetes.

Impaired wound healing is one of the most common complications associated with diabetes. Adiponectin is an abundant circulating adipocyte-derived cytokine that has beneficial effects on disorders accompanying diabetes. Herein we report that adiponectin has a regulatory effect on the growth and differentiation of HaCaT human keratinocyte cells. Furthermore, adiponectin regulated the expression of TGFbeta isoforms in keratinocytes in a dose-dependent manner, which implies that adiponectin modulates other types of cells related to wound repair via secretion of growth factors from keratinocytes. Moreover, TUNEL assay results revealed that adiponectin enhances apoptosis of keratinocytes. Taken together, the present results indicate that adiponectin has suppressive effects on the formation of hyperkeratosis commonly seen in patients with diabetic foot and its application may be beneficial for developing treatment for that disorder.

Fronto-facial monobloc advancement with rigid external distraction (RED-II) system.

Fronto-facial monobloc advancement is one of the most rewarding procedures for upper and mid-face reconstruction in patients with craniosynostosis. However, it has challenging aspects. Epidural abscess and frontal bone necrosis after retrofrontal dead space is one of the major complications and has led many experienced surgeons not to continue with the procedure. Bone distraction can play a great role in preventing these problems. The Rigid External Distraction (RED-II) system is a external distraction device using the cranium as an anchorage point. In two craniosynostosis cases, fronto-facial monobloc advancement with the system was performed. Controllability of the monobloc segment increased significantly. Operative time and blood loss were lessened. No major complications were experienced.

Simultaneous manifestation of squamous cell carcinoma in identical twins with epidermolysis bullosa.

We report a case of identical twins with recessive dystrophic epidermolysis bullosa, who developed squamous cell carcinoma in the hand at the latter half of their third decade. To our knowledge, this is the first case of manifestation of squamous cell carcinoma in identical twins and may contribute to the understanding of oncogenesis in such patients.

Growth Factor Measurement and Histological Analysis in Platelet Rich Fibrin: A Pilot Study

ObjectiveThe aim of this study was to compare growth factor amount contained in platelet rich fibrin (PRF) and compare with that in platelet rich plasma (PRP), and in whole blood. And also to investigate distribution of growth factors and cellular components in PRF.Materials and MethodsPRF and PRP were obtained from the same sample of peripheral blood. Extraction of proteins were done with lysis buffer, accompanied by freeze and thaw procedures. Concentration of two representative growth factors in platelets: platelet derived growth factor (PDGF) and transforming growth factor beta (TGF-β), were measured with enzyme-linked immunosorbent assay (ELISA). PRF was cut into three parts: (top, middle and bottom), and growth factor concentration was measured respectively. Paraffin embedded section of PRF was observed with Giemsa stain. Immuno-histochemical analysis with anti-PDGF and anti-TGF-β antibodies was also conducted.ResultsThe growth factor levels in PRF was higher than in peripheral blood and comparable to those in PRP. Growth factor levels in bottom part of PRF was much higher than in top and middle part. Microscopically, platelets and mono-nucleated cells were concentrated just above the yellow–red interface. Poly-nucleated cells were concentrated below the interface.ConclusionThe growth factors were surely concentrated in PRF. This result can support basis of good clinical outcomes. For effective application of PRF, the knowledge that growth factors and cells are not equally distributed in PRF should be utilized.

Hypertrophic scar contracture is mediated by the TRPC3 mechanical force transducer via NFkB activation

Wound healing process is a complex and highly orchestrated process that ultimately results in the formation of scar tissue. Hypertrophic scar contracture is considered to be a pathologic and exaggerated wound healing response that is known to be triggered by repetitive mechanical forces. We now show that Transient Receptor Potential (TRP) C3 regulates the expression of fibronectin, a key regulatory molecule involved in the wound healing process, in response to mechanical strain via the NFkB pathway. TRPC3 is highly expressed in human hypertrophic scar tissue and mechanical stimuli are known to upregulate TRPC3 expression in human skin fibroblasts in vitro. TRPC3 overexpressing fibroblasts subjected to repetitive stretching forces showed robust expression levels of fibronectin. Furthermore, mechanical stretching of TRPC3 overexpressing fibroblasts induced the activation of nuclear factor-kappa B (NFκB), a regulator fibronectin expression, which was able to be attenuated by pharmacologic blockade of either TRPC3 or NFκB. Finally, transplantation of TRPC3 overexpressing fibroblasts into mice promoted wound contraction and increased fibronectin levels in vivo. These observations demonstrate that mechanical stretching drives fibronectin expression via the TRPC3-NFkB axis, leading to intractable wound contracture. This model explains how mechanical strain on cutaneous wounds might contribute to pathologic scarring.

Supplementation of bone marrow aspirate-derived platelet-rich plasma for treating radiation-induced ulcer after cardiac fluoroscopic procedures: A preliminary report

Background: The frequency of encountering radiodermatitis caused by X-ray fluoroscopic procedures for ischaemic heart disease is increasing. In severe cases, devastating ulcers with pain, for which conservative therapy is ineffective, emerge. Radiation-induced ulcers are notorious for being difficult to treat. Simple skin grafting often fails because of the poor state of the wound bed. A vascularized flap is a very good option. However, the non-adherence of the well-vascularized flap with the irradiated wound bed is frequently experienced. Aim: To ameliorate the irradiated wound bed, bone marrow-derived platelet-rich plasma (bm-PRP) was delivered during the surgery. Materials and Methods: Four patients with severe cutaneous radiation injury accompanied by unbearable pain after multiple fluoroscopic procedures for ischaemic heart disease were treated. Wide excision of the lesion and coverage with a skin flap supplemented with bm-PRP injection was performed. Results: All patients obtained wound closure and were relieved from pain. No complication concerning the bone marrow aspiration and delivery of bm-PRP was observed. Conclusions: Supplementation of bm-PRP can be an option without major complications, time, and cost to improve the surgical outcome for irradiated wounds.

STAT6-positive intraorbital papillary tumor: A rare variant of solitary fibrous tumor?

We experienced a peculiar case of orbital mesenchymal tumor in a 22-year-old Japanese woman. The tumor showed a papillary proliferating pattern, but no typical hemangiopericytomatous staghorn vessels. The tumor was composed of round to oval shaped cells with oval nuclei and mild nuclear atypia. Abundant vascular cores were present in the central portion of papillary proliferations of tumor cells. Immunohistochemistry revealed that the tumor cells were positive for CD34 and bcl2. Moreover, they showed positive nuclear signals of STAT6, which have recently been shown to be specific for solitary fibrous tumors. In the literature, only one case of solitary fibrous tumor with papillary and retiform growth pattern has been reported, but the case partially showed the typical staghorn vessel pattern. Although the definite diagnosis is difficult in the settings of the unusual histology and the deficiency of NAB2-STAT6 fusion, it is possible that this STAT6-positive intraorbital papillary tumor is a very rare variant of solitary fibrous tumor.

A new mouse model of impaired wound healing after irradiation

Abstract Radiation has many benefits and is an important treatment for cancer therapy. However, it also has unfavourable side-effects. Among these side-effects, the impairment of wound healing in the skin is a major problem in clinics. Although many attempts have been made to overcome this shortcoming, there are few effective treatments for impaired wound healing after irradiation. One reason for this is that it is hard to obtain good animal models for researching this topic. In this study, two different models were created and investigated. In one model, rectangular flaps were created on the backs of mice and irradiated while the other parts of their bodies were covered with a lead board. In another model, the lower limbs were exposed to radiation. In each model, several doses of irradiation were tested. Skin ulcers were created in the irradiated area, and the wound healing process was observed. In order to verify the usefulness of the model, adipose derived stromal cells were injected into the wound and the healing rate was calculated. In the flap model, the flaps contracted and formed linear scars. On the other hand, in the thigh model, 15 Gy irradiation resulted in slow wound healing but no strong inflammation or necrosis. The transplantation of adipose tissue derived stromal cells into the irradiated thigh wound improved the wound healing. This study suggested that irradiation of the lower limb at ∼ 15 Gy might be an appropriate model for basic research into wound healing in irradiated skin.

Influence of continuous or intermittent negative pressure on bacterial proliferation potency in vitro.

Abstract Negative pressure wound therapy is helpful and effective in the treatment of intractable skin ulcers and defects, not only acute wounds. However, application of negative pressure wound therapy for an infected wound is still controversial. The authors developed an in-vitro model of negative pressure wound therapy and investigated the influence of various types of negative pressure environment on the proliferation potency of non-pathogenic Escherichia coli. E. coli in Luria-Bertani liquid media was cultured at 37°C under different environments, which were normal atmosphere in group 1, continuous negative pressure of 75 mmHg in group 2, intermittent negative pressure of 75 mmHg with cycle time of 1 minute aspiration and 1 minute abeyance in group 3, with the one of 3 minutes aspiration and 3 minutes abeyance in group 4. The relative amounts of E. coli in each group were investigated at different times. The proliferation potency of E. coli was higher under negative pressure than under normal atmosphere; higher under intermittent negative pressure than under continuous negative pressure; and higher under intermittent negative pressure with a short cycle than with a long cycle. It is important to consider the possibility that the intermittent and continuous mode of negative pressure wound therapy may promote proliferation of bacteria in an infected wound with no blood flow like necrotic tissue.