Mechanical and biological properties of poly-ε-caprolactone membrane for pleurodesis: A preclinical study in pigs.

BACKGROUND/PURPOSE: Biomaterial implants are emerging as a treatment choice for pleurodesis; however, the optimal biomaterial and form for managing spontaneous pneumothorax, particularly post-video-assisted thoracic surgery, remain under investigation. This study evaluated the mechanical and biological properties of the poly-ε-caprolactone (PCL) membrane as a sclerosing agent for pleurodesis in Landrace pigs. METHODS: Twenty-four Landrace pigs were split into two groups for mechanical abrasion and PCL membrane pleurodesis, with the latter group's PCL meshes inserted using video-assisted thoracic surgery. The mechanical and biological properties of the PCL membrane were assessed in pigs at three, six, and 12 months after the procedure. This assessment involved a range of techniques, such as the T-Peel test, macroscopic evaluation with a scoring scale, microscopic examination, and biomechanical and molecular weight analysis. RESULTS: The PCL membrane group outperformed the traditional abrasion group, with stronger adhesions seen over longer implantation durations. This group also showed superior and more consistent results in both macroscopic and microscopic evaluations compared to the control group. The membrane-based method was easier and faster to perform than the control group's method, and importantly, no mortality occurred following membrane implantation. CONCLUSION: This study is the pioneering effort to present long-term findings regarding the mechanical and biological properties of the PCL membrane in an in vivo animal model. The membrane demonstrated better adhesion ability than that of traditional abrasion and showed reassuring biocompatibility in both the pig model, suggesting its potential as treatment for patients with primary spontaneous pneumothorax. Further clinical studies are needed to support these observations.

The cellular responses of corneal fibroblasts to cyclic stretching loads.

Mechanical signaling plays a crucial role in maintaining extracellular matrix (ECM) homeostasis in various structures. In this study, we investigated the responses of corneal fibroblasts to cyclic stretching loads using an in vitro cell culture system. Bovine corneal fibroblasts were cultured and subjected to equibiaxial cyclic strain of 15% for 72 h at a frequency of 0.25 Hz, with bovine skin fibroblasts used as a comparison. We explored various cellular behaviors, including morphological changes, cell proliferation, and metabolism in response to mechanical stretching loads. The expression of genes, protein secretion, and enzymatic activity for several major metalloproteinases was also determined through Q-PCR, Western blot, and gel zymography. Additionally, we investigated the involvement of mitogen-activated protein kinases (MAPKs) signaling pathways in the corneal fibroblasts when subjected to mechanical stimuli. Our findings revealed that, compared to skin fibroblasts, corneal fibroblasts were reluctant to morphological changes in response to a prolonged (72 h) and high-amplitude (15% of strain) cyclic stretching load. However, cyclic stretching loads stimulated the upregulation of MMP-2 expression in corneal fibroblasts via the MAPK signaling pathways involving extracellular signal-regulated kinase and p38. Together with a lack of upregulation in type I collagen expression, our results indicate the induction of the ECM degradation process in corneal fibroblasts in response to cyclic stretching. These findings emphasize the mechanoresponsive nature of corneal fibroblasts and shed light on the potential impact of intense mechanical stress on the cornea in both normal and pathological conditions such as keratoconus, providing valuable insights for understanding corneal mechanobiology.

Overexpression of N-acetylglucosaminyltransferase V promotes human parotid gland acinar cell immortalization via the epidermal receptor activation.

The purpose of this study is to maintain the proliferation capability of human parotid gland acinar cells (ACs) in vitro to extend passage number and to study the mechanism that regulates AC stemness. N-acetylglucosaminyltransferase V (GnT-V) is the Golgi enzyme, and it has been reported that the ß1,6GlcNAc-branched N-linked glycans are associated with various cell behaviors. Therefore, we modify the gene expression of ACs by transfection of the GnT-V-overexpression plasmid, and we found that upregulation of GnT-V extensively increased ACs proliferation and stemness properties in ACs/GnT-V compared to ACs transfected with Mock plasmid. More importantly, we observed that high levels of GnT-V positively correlated with ALDH1A3 expression via increasing phosphorylation of cell surface receptors and activating the downstream signaling transduction. Hence, the current study suggested that GnT-V is a significant factor for cell immortalization in the ACs model by activating the EGFR/ERK/ALDH1A3 signaling pathway.

A simple method to improve the antibiotic elution profiles from polymethylmethacrylate bone cement spacers by using rapid absorbable sutures.

OBJECTIVE: Antibiotic-loaded bone cement beads and spacers have been widely used for orthopaedic infection. Poor antibiotic elution is not capable of eradicating microbial pathogens and could lead to treatment failure. The elution profiles differ among different cement formulations. Although Simplex P cement has the least release amount, it is widely used due to its ready availability. Previous methods aiming to improve the elution profiles were not translated well to clinical practice. We sought to address this by using easily available materials to improve the elution profile of antibiotics from PMMA, which allows clinicians to implement the method intraoperatively. METHODS: Vancomycin was mixed with Simplex P cement. We used Vicryl Rapide sutures to fabricate sustained-release cement beads by repetitively passing the sutures through the beads and/or mixing suture segments into the cement formulation. Vancomycin elution was measured for 49 days. The mechanism of antibiotic release was observed with gross appearance and scanning electron microscopic images. The antimicrobial activities against MRSA were tested using an agar disk diffusion bioassay. RESULTS: Passing Vicryl Rapide sutures through cement beads significantly improved the elution profiles in the 7-week period. The increased ratios were 9.0% on the first day and 118.0% from the 2nd day to the 49th day. Addition of suture segments did not increase release amount. The Vicryl Rapide sutures completely degraded at the periphery and partially degraded at the center. The antibiotic particles were released around the suture, while antibiotic particles kept densely entrapped in the control group. The antimicrobial activities were stronger in passing suture groups. CONCLUSION: Passing fast absorbable sutures through PMMA cement is a feasible method to fabricate sustained-release antibiotic bone cement. Intra-cement tunnels can be formed, and the effect can last for at least 7 weeks. It is suitable for a temporary spacer between two stages of a revision surgery.

Biological properties of human periodontal ligament cell spheroids cultivated on chitosan and polyvinyl alcohol membranes.

BACKGROUND/PURPOSE: Multicellular spheroid cultures have attracted increasing attention in the field of periodontal regeneration. However, very few studies have reported the periodontal ligament (PDL) cell spheroid formation via biomaterials-induced processes. This study investigated the biological characteristics of human PDL cell spheroids formed on two hydrophilic polymer-based biomaterials, namely chitosan and polyvinyl alcohol. METHODS: The expressions of periostin, paxillin, hypoxia-inducible factor 1-α (HIF-1α), and vascular endothelial growth factor (VEGF) were analyzed. Cell migration ability was assessed using a scratch assay. Furthermore, PDL cell spheroids were cultured in 3D-printed polylactic acid scaffolds to evaluate mineralizing capability. RESULTS: Western blot analysis revealed increased expressions of periostin, HIF-1α, and VEGF in the 3D spheroids. After the spheroids were reseeded, the cells gradually migrated outward from the spheroids and time-dependent distribution of paxillin was observed. The cells migrating outward from the 3D spheroids demonstrated greater migration ability than that of 2D monolayer cells. Compared to the dissociated cells from a monolayer culture, the cell spheroids formed on the chitosan membrane exhibited elevated alkaline phosphatase activity and an increase in mineralized matrix deposition. CONCLUSION: The biomaterial-induced formation of PDL cell spheroids suggests a novel strategy for cell delivery in research and clinical applications of periodontal regeneration.

Development of Injectable Calcium Sulfate and Self-Setting Calcium Phosphate Composite Bone Graft Materials for Minimally Invasive Surgery.

The demand of bone grafting is increasing as the population ages worldwide. Although bone graft materials have been extensively developed over the decades, only a few injectable bone grafts are clinically available and none of them can be extruded from 18G needles. To overcome the existing treatment limitations, the aim of this study is to develop ideal injectable implants from biomaterials for minimally invasive surgery. An injectable composite bone graft containing calcium sulfate hemihydrate, tetracalcium phosphate, and anhydrous calcium hydrogen phosphate (CSH/CaP paste) was prepared with different CSH/CaP ratios and different concentrations of additives. The setting time, injectability, mechanical properties, and biocompatibility were evaluated. The developed injectable CSH/CaP paste (CSH/CaP 1:1 supplemented with 6% citric acid and 2% HPMC) presented good handling properties, great biocompatibility, and adequate mechanical strength. Furthermore, the paste was demonstrated to be extruded from a syringe equipped with 18G needles and exerted a great potential for minimally invasive surgery. The developed injectable implants with tissue repairing potentials will provide an ideal therapeutic strategy for minimally invasive surgery to apply in the treatment of maxillofacial defects, certain indications in the spine, inferior turbinate for empty nose syndrome (ENS), or reconstructive rhinoplasty.

Developing a Glyoxal-Crosslinked Chitosan/Gelatin Hydrogel for Sustained Release of Human Platelet Lysate to Promote Tissue Regeneration.

The clinical application of human platelet lysate (HPL) holds promise for tissue regeneration, and the development of an efficient vehicle for its delivery is desired. Chitosan-based hydrogels are potential candidates, but they often exhibit weak mechanical properties. In this study, a chitosan/gelatin (CS-GE) hydrogel crosslinked by glyoxal was fabricated for sustained release of HPL. The influence of HPL on Hs68 fibroblast and human umbilical vein endothelial cell (HUVEC) culture was evaluated, and we found that supplementing 5% HPL in the medium could significantly improve cell proliferation relative to supplementing 10% fetal bovine serum (FBS). Moreover, HPL accelerated the in vitro wound closure of Hs68 cells and facilitated the tube formation of HUVECs. Subsequently, we fabricated CS-GE hydrogels crosslinked with different concentrations of glyoxal, and the release pattern of FITC-dextrans (4, 40 and 500 kDa) from the hydrogels was assessed. After an ideal glyoxal concentration was determined, we further characterized the crosslinked CS-GE hydrogels encapsulated with different amounts of HPL. The HPL-incorporated hydrogel was shown to significantly promote the proliferation of Hs68 cells and the migration of HUVECs. Moreover, the release pattern of transforming growth factor-ß1 (TGF-ß1) and platelet-derived growth factor-BB (PDGF-BB) from hydrogel was examined in vitro, demonstrating a sustained release profile of the growth factors. Finally, the chick chorioallantoic membrane assay revealed that HPL encapsulation in the hydrogel significantly stimulated angiogenesis in ovo. These results demonstrate the great potential of the crosslinked CS-GE hydrogel to serve as an effective delivery system for HPL to promote tissue regeneration.

A self-assembled layer-by-layer surface modification to fabricate the neuron-rich model from neural stem/precursor cells.

BACKGROUND/PURPOSE: In vitro neural cell-based models have been widely used to mimic the in vivo neural tissue environments and quantitatively understand the effects of pharmaceutical molecules on neural diseases. Recently, several biomimetic neural tissue models have been widely developed by using biomaterials or surface modification. However, the complex protocols of material synthesis or surface modification lack an easy execution to fabricate the neuron favorite environment. METHODS: In this study, we utilized a layer-by-layer technique as a surface modification method for regulating the behaviors of neural stem/precursor cells (NSPCs) on material surfaces. Polyelectrolyte multilayers (PEMs) via alternate deposition of poly (allylamine hydrochloride) (PAH) and poly (sodium-4-styrenesulfonate) (PSS) were used to culture NSPCs. After incubation for 7 days, the neuronal differentiation of NSPCs and synapse function of differentiated neurons were identified by immunocytochemistry for lineage specific markers. RESULTS: Compared with the only PAH film, the PSS-ending film (neuron-rich model) was shown to significantly promote differentiation of NSPCs into neurons (more than 50%), form a neuronal network structure; and differentiated neurons exhibiting functional synaptic activity. CONCLUSION: This study shows that the PEMs provided an easily alternative approach to modify the surface properties; and might be a method to obtain a neuron-rich model for the biological/pharmaceutical applications.

Investigating the effect of chitosan/ polycaprolactone blends in differentiation of corneal endothelial cells and extracellular matrix compositions.

This study aimed to investigate the underlying mechanisms of corneal endothelial cells (CECs) differentiation and identify the extracellular matrix (ECM) compositions using chitosan/polycaprolactone (PCL) blended membrane, hence exploring the potential use of chitosan/PCL blends in tissue engineering of CECs. We utilized the chitosan/PCL blends named as PCL25 consisting of PCL at 25% by weight. The surface characteristics of PCL25 were confirmed by using Fourier Transform Infrared Spectroscopy (FTIR) and Atomic Force Microscope (AFM). Bovine CECs were cultured on the blends, compared with TCPS and pure chitosan membrane. Cell behaviors in terms of cell attachment, proliferation, differentiation phenotype and expression of differentiation proteins were examined. Furthermore, ECM protein productions were also analyzed. From the experiments, we found the topography (roughness) of PCL25 membrane examined by AFM was greater than pure chitosan membrane. FTIR results confirmed the functional groups of C=O bond of PCL. The CECs displayed hexagonal morphology and similar proliferation rate on both PCL25 membrane and TCPS. In addition, the immunofluorescence evidence showed well-localized ZO-1 and Na+/K+ ATPase expression of membrane proteins. ECM protein productions of CECs on PCL were no inferior to TCPS. Moreover, western blot results verified the higher amount of collagen type IV, and reduced TGF-ß2 expression on PCL25 membrane compared to TCPS substrate. In conclusions, chitosan/PCL blends membrane provided a favorable environment for CECs in terms of ECM compositions, therefore enhancing the growth and differentiation. Accordingly, for CEC tissue engineering applications, PCL 25 might be a suitable alternative for cadaveric cornea transplantation in the near future.

Increased Cell Detachment Ratio of Mesenchymal-Type Lung Cancer Cells on pH-Responsive Chitosan through the ß3 Integrin.

Chitosan is sensitive to environmental pH values due to its electric property. This study investigates whether the pH-responsive chitosan assay can provide a simple method to evaluate the aggressive behavior of cancer cells with cell detachment ratio. The epithelial-mesenchymal transition (EMT) is induced with transforming growth factor-ß1 (TGF-ß1) in the human non-small cell lung cancer cell line (A549). EMT-induced cells and untreated cells are cultured on chitosan substrates at pH 6.99 for 24 h, followed by pH 7.65 for 1 h. The cell detachment ratio (CDR) on pH-responsive chitosan rises with an increasing of the TGF-ß1 concentration. The protein array reveals that the expression levels of the α2, α3, α5, ß2, and ß3 integrins are higher in EMT-induced A549 cells than in untreated cells. A further inhibition assay shows that adding ß3 integrin blocking antibodies significantly decreases the CDR of EMT-induced cells from 32.7 ± 5.7% to 17.8 ± 2.1%. The CDR of mesenchymal-type lung cancer cells increases on pH-responsive chitosan through the ß3 integrin. Notably, the CDR can be theoretically predicted according to the individual CDR on the pH-responsive chitosan surface, irrespective of heterogeneous cell mixture. The pH-responsive chitosan assay serves as a simple in vitro model to investigate the aggressive behavior of lung cancer including the heterogeneous cell population.

Characteristics of melanocyte spheroids formed through different biomaterial-induced processes.

BACKGROUND/PURPOSE: Cell behaviors in three-dimensional spheroids are known to be different from those in monolayer cultures; however, very few studies have compared the characteristics of cell spheroids formed through different biomaterial-induced processes. This study investigated the mechanism of melanocyte spheroid formation by using membranes composed of two hydrophilic polymer-based biomaterials, namely chitosan and polyvinyl alcohol (PVA). Our findings revealed that different spheroid-forming processes occurred on the two biomaterials. METHODS: Human melanocytes were provided by the cell bank of the Department of Dermatology, National Taiwan University Hospital. The cell viability was determined through the MTT (3-(4,5-dimethylthiazol-2-yl)-diphenyl tetrazolium bromide; Sigma) colorimetric assay. The cell living rate was determined using the trypan blue exclusion test. The amount of fibronectin adsorbed was quantified through Western blot analysis. Statistical significance was calculated using one-way analysis of variance (ANOVA) followed by Duncan's test, and p values <0.05 or <0.01 was considered significant. RESULTS: In the study, the melanocytes attached to, migrated on, and aggregated on the chitosan surface and then formed spheroids. By contrast, on the PVA surface, the melanocytes directly aggregated to form three-dimensional spheres in suspension. The proliferative ability and survival rate of the melanocytes were considerably higher on the chitosan membranes than on the PVA membranes. CONCLUSION: We concluded that only cell-cell interactions dominated in melanocytes seeded on the PVA membrane, whereas cell-cell and cell-substrate interactions occurred on the chitosan membranes and further enhanced cellular functions. The chitosan-induced spheroids could probably overcome the diffusion and assimilation of trophic factors.

Far-infrared ray radiation promotes neurite outgrowth of neuron-like PC12 cells through AKT1 signaling.

BACKGROUND/PURPOSE: Far-infrared (FIR) therapy is a safe and noninvasive source for medical applications. Animal study has shown the effects of FIR in promoting nerve repair. However, the cellular mechanism is not well known. Nerve growth factor (NGF) treated neuron-like PC12 cells for neurite outgrowth have been widely employed as the in vitro model for neural regeneration. METHODS: In this study, we tried to evaluate the potential of FIR in promoting neurite outgrowth and related mechanism by using NGF-treated neuron-like PC12 cells as a cellular model. We found that FIR could promote neurites outgrowth of neuron-like PC12 cells at earlier culture period. RESULTS: The neurite outgrowth-enhancing effect of FIR irradiation was more obvious when lower NGF concentration (1 ng/ml and 10 ng/ml) was added into the medium. We also found that FIR had no thermal effects on culture medium. The effects of FIR in promoting neurite outgrowth were dose dependent, and higher power density of FIR provided more effects for improving neurite outgrowth. The mechanism of FIR in promoting neurite outgrowth was through AKT1 pathway. CONCLUSION: The effects of FIR irradiation on promoting neurite outgrowth and neural regeneration of NGF-treated neuron-like PC12 cells are dose dependent and through activation of AKT1 phosphorylation. This study provided important information for understanding the cellular mechanism of FIR in promoting neurite outgrowth and possible neural regeneration for further clinical applications.

Aggregation of human dental pulp cells into 3D spheroids enhances their migration ability after reseeding.

Multicellular three-dimensional (3D) spheroids allow intimate cell-cell communication and cell-extracellular matrix interaction. Thus, 3D cell spheroids better mimic microenvironment in vivo than two-dimensional (2D) monolayer cultures. The purpose of this study was to evaluate the behaviors of human dental pulp cells (DPCs) cultured on chitosan and polyvinyl alcohol (PVA) membranes. The protein expression of hypoxia-inducible factor 1-α (HIF-1α) and vascular endothelial growth factor (VEGF), and the migration ability of the DPCs from 2D versus 3D environments were investigated. The results showed that both chitosan and PVA membranes support DPCs aggregation to form multicellular spheroids. In comparison to 2D cultures on tissue culture polystyrene, DPC spheroids exhibited higher protein expression of HIF-1α and VEGF. The treatment with YC-1 (inhibitor to HIF-1α) blocked the upregulation of VEGF, indicating a downstream event to HIF-1α expression. When DPC spheroids were collected and subjected to the transwell assay, the cells growing outward from 3D spheroids showed greater migration ability than those from 2D cultures. Moreover, DPCs aggregation and spheroid formation on chitosan membrane were abolished by Y-27632 (inhibitor to Rho-associated kinases), whereas the inhibitory effect did not exist on PVA membrane. This suggests that the mechanism regulating DPCs aggregation and spheroid formation on chitosan membrane is involved with the Rho-associated kinase signaling pathway. In summary, the multicellular spheroid structure was beneficial to the protein expression of HIF-1α and VEGF in DPCs and enhanced the migration ability of the cells climbing from spheroids. This study showed a new perspective in exploring novel strategies for DPC-based research and application.

Therapeutic vaccine targeting Epstein-Barr virus latent protein, LMP1, suppresses LMP1-expressing tumor growth and metastasis in vivo.

BACKGROUND: In endemic area, nasopharyngeal carcinoma (NPC) tumor cells harbor EBV latent infection and expresses viral antigens such as EBNA1, LMP1 and LMP2. In this study, we established a NPC-mimicry animal model and assessed the therapeutic potential of LMP1 vaccine. METHODS: Animal models were established by injection of LMP1-expressing TC-1 cells in C57BL6/J mice subcutaneously or through tail veins. pcDNA3.1 empty vector or LMP1/pcDNA3.1 vaccine was delivered by a helium-driven gene gun. Effectiveness of vaccine was evaluated by measuring the tumor size and numbers of metastatic lung nodules. Circulating cytokines were evaluated by ELISArray. Populations of activated cytotoxic T lymphocytes (CTLs) and LMP1-specific T lymphocytes were evaluated by flow cytometry with CD8/CD107a double staining and interferon-γ ELISPOT assay, respectively. RESULTS: LMP1 vaccine significantly suppressed tumor growth (n = 3) and metastasis (n = 4) in vivo. When vaccinated before tumor challenge, all mice in vaccine group were tumor-free, whereas all mice in the control group developed tumors within 2 weeks after tumor challenge (n = 10). Cytokine ELISArray revealed elevation of a panel of proinflammatory cytokines in mice receiving LMP1 vaccine. Flow cytometry and interferon-γ ELISPOT assay revealed that LMP1 vaccine induced larger populations of activated CTLs and LMP1-specific T lymphocytes. CONCLUSIONS: This pre-clinical study provides a promising result that LMP1 vaccine suppresses LMP1-expressing tumor growth and metastasis in vivo.

Study of poly-ɛ-caprolactone membranes for pleurodesis.

BACKGROUND/PURPOSE: Pleurodesis with biomaterial membrane is an emerging treatment method for pneumothorax. However, the ideal one for the common disease is still under debate. METHODS: We investigate the Poly-ε-caprolactone (PCL) membrane pleurodesis by using New Zealand White rabbits, which was sacrificed for examination one month later. Moreover, inflammation and fibrosis scoring were done under microscopic evaluation, as well as Western blot analysis in vitro and in vivo. RESULTS: Gross evaluation of pleurodesis score revealed that dense PCL membrane produced moderate pleural adhesion, while porous PCL membrane exhibited significantly higher pleurodesis scores. CONCLUSION: PCL membrane induced significant degree of adhesion, both within the abdomen and chest of the rabbits. The porous PCL membrane produces more intensive adhesion than dense one. Fibronectin plays an important role in the process of pleurodesis. Further study is required for the clinical application of the promising material.

High glucose-induced reactive oxygen species generation promotes stemness in human adipose-derived stem cells.

BACKGROUND AIMS: Adipose-derived stem cells (ASCs) represent an important source of cell therapy to treat diabetic complications. However, hyperglycemia may alter several cellular functions, so the present study aimed to investigate the influence of a diabetic environment on the stemness and differentiation capabilities of ASCs. METHODS: Human ASCs were obtained from subcutaneous adipose tissues of diabetic (dASCs) and nondiabetic donors (nASCs) and characterized. To reproduce an in vitro hyperglycemia environment, the nASCs were also cultured under prolonged high-glucose (HG; 4.5 g/L) or low-glucose (LG; 1.0 g/L) conditions. RESULTS: The expression of cell surface markers in dASCs and nASC was similar and characteristic of mesenchymal stem cells. Although dASCs or HG-treated nASCs exhibited decreased proliferation, enhanced expression of the pluripotent markers Sox-2, Oct-4, and Nanog was observed. Moreover, HG-treated nASCs exhibited decreased cell migration, enhanced senescence, and significantly higher intracellular reactive oxygen species (ROS), whereas their adipogenic and osteogenic differentiation capacities remained comparable to LG-treated cells. With antioxidant treatment, HG-treated nASCs showed improved cell proliferative activity without stemness enhancement. This HG-induced biological response was associated with ROS-mediated AKT attenuation. When cultured in an appropriate induction medium, the HG-treated nASCs and dASCs exhibited enhanced potential of transdifferentiation into neuron-like cells. DISCUSSION: Despite lower proliferative activity and higher senescence in a diabetic environment, ASCs also exhibit enhanced stemness and neurogenic transdifferentiation potential via a ROS-mediated mechanism. The information is important for future application of autologous ASCs in diabetic patients.

Novel microinjector for carrying bone substitutes for bone regeneration in periodontal diseases.

BACKGROUND/PURPOSE: Traditionally, guide bone regeneration (GBR) was a widely used method for repairing bone lost from periodontal disease. There were some disadvantages associated with the GBR method, such as the need for a stable barrier membrane and a new creative cavity during the surgical process. To address these disadvantages, the purpose of this study was to evaluate a novel microinjector developed for dental applications. The microinjector was designed to carry bone graft substitutes to restore bone defects for bone regeneration in periodontal diseases. The device would be used to replace the GBR method. METHODS: In this study, the injected force and ejected volume of substitutes (including air, water, and ethanol) were defined by Hooke's law (n = 3). The optimal particle size of bone graft substitutes was determined by measuring the recycle ratio of bone graft substitutes from the microinjector (n = 3). Furthermore, a novel agarose gel model was used to evaluate the feasibility of the microinjector. RESULTS: The current study found that the injected force was less than 0.4 N for obtaining the ejected volume of approximately 2 mL, and when the particle size of tricalcium phosphate (TCP) was smaller than 0.5 mm, 80% TCP could be ejected from the microinjector. Furthermore, by using an agarose model to simulate the periodontal soft tissue, it was also found that bone graft substitutes could be easily injected into the gel. CONCLUSION: The results confirmed the feasibility of this novel microinjector for dental applications to carry bone graft substitutes for the restoration of bone defects of periodontal disease.

Citrus polyphenol for oral wound healing in oral ulcers and periodontal diseases.

BACKGROUND/PURPOSE: Various polyphenolic compounds from plants have been confirmed to have different pharmaceutical functions. The purpose of this study was to evaluate citrus polyphenol (CP) for dental applications. A medium with CP was developed to improve oral wound healing. The CP could be used as a supplemental compound in mouthwash for periodontal diseases. METHOD: In this study, the metabolic activity and cell toxicity of CP (1%, 0.1%, and 0.01%) for fibroblasts were investigated by MTT and lactate dehydrogenase assays (n = 6). The effect of CP on motility of fibroblast was also evaluated via a wound healing model. RESULTS: The growth of Hs68 cells on TCPS was greatly increased in the presence of 0.01% CP. In addition, the significant difference (p<0.01) of cell toxicity of fibroblast was observed after 6 days in 0.01% CP medium. Using the wound healing model, it was also found that CP could enhance the migratory ability of fibroblasts. CONCLUSION: The results confirm the feasibility of CP be a supplemental compound in mouthwash for treatment of periodontal diseases in dental application to improve wound healing in the mouth.

Inhibition of growth and migration of oral and cervical cancer cells by citrus polyphenol.

BACKGROUND/PURPOSE: It has been confirmed that polyphenolic compounds present in food have various pharmaceutical functions. The purpose of this study was to evaluate citrus polyphenol (CP) for dental applications. The culture medium with CP was developed to inhibit the proliferation of oral cancer cells. CP could be used as a supplemental compound for topical application for oral cancer patients. METHODS: In this study, the metabolic activity and cell toxicity of CP (at concentrations of 1%, 0.1%, and 0.01%) for oral and cervical cancer cells were investigated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide and lactate dehydrogenase assays (n = 6). Furthermore, the effects of CP on motilities of oral and cervical cancer cells were also evaluated using a scratch assay model. RESULTS: We found that the growth of Ca9-22 and HeLa cells on tissue culture polystyrene was greatly inhibited when 1% CP was added to the medium. In addition, significant differences (p < 0.01) in cytotoxicities of oral and cervical cancer cells were observed after 6 days in the culture medium to which 1% CP was added. Furthermore, using a scratch assay model to evaluate the migratory abilities of oral and cervical cancer cells, it was also found that CP could inhibit the migratory abilities of cancer cells. CONCLUSION: The results confirmed the feasibility of the topical application of CP as a supplemental compound for inhibition of cancer cell proliferation and migration.

Patient-centered wound teleconsultation for cutaneous wounds: a feasibility study.

INTRODUCTION: The purpose of this study was to investigate the feasibility of patient-centered teleconsultation for various cutaneous wounds by using store-and-forward technology. MATERIALS AND METHODS: From July 2011 to November 2011, 53 patients with various wound conditions were enrolled in this study. The patients took their own wound images shortly before face-to-face consultations with a plastic surgeon, and the images were sent via e-mail to another 3 remote plastic surgeons along with brief medical information. All 4 surgeons completed a standard questionnaire individually, which addressed questions regarding the presence of wound conditions (gangrene, necrosis, erythema, and cellulitis/infection), as well as suggested clinical treatment with antibiotics and debridement. The evaluations were compared among the 3 remote surgeons as well as the remote and onsite surgeons. RESULTS: The 53 wounds included in our study exhibited different causative mechanisms and locations on the body. The concordances between the remote and onsite surgeons were 92%, 79%, 83%, and 85% regarding the presence of gangrene, necrosis, erythema, and cellulitis/infection, respectively. The agreement rates regarding the treatment suggestion with antibiotic use and debridement between the remote surgeons and the onsite surgeon were both 83%. The remote surgeons reported high specificity, at least 84%, in all parameters of wound descriptions or treatment suggestions. CONCLUSIONS: The patient-centered teleconsultation system based on store-and-forward technology is a feasible tool for wound management, and it shows promises in future clinical applications by decreasing clinic visits.