Genetic profiling of human bone marrow and adipose tissue-derived mesenchymal stem cells reveals differences in osteogenic signaling mediated by graphene.

BACKGROUND: In the last decade, graphene surfaces have consistently supported osteoblast development of stem cells, holding promise as a therapeutic implant for degenerative bone diseases. However, until now no study has specifically examined the genetic changes when stem cells undergo osteogenic differentiation on graphene. RESULTS: In this study, we provide a detailed overview of gene expressions when human mesenchymal stem cells (MSCs) derived from either adipose tissue (AD-MSCs) or bone marrow (BM-MSCs), are cultured on graphene. Genetic expressions were measured using osteogenic RT2 profiler PCR arrays and compared either over time (7 or 21 days) or between each cell source at each time point. Genes were categorized as either transcriptional regulation, osteoblast-related, extracellular matrix, cellular adhesion, BMP and SMAD signaling, growth factors, or angiogenic factors. Results showed that both MSC sources cultured on low oxygen graphene surfaces achieved osteogenesis by 21 days and expressed specific osteoblast markers. However, each MSC source cultured on graphene did have genetically different responses. When compared between each other, we found that genes of BM-MSCs were robustly expressed, and more noticeable after 7 days of culturing, suggesting BM-MSCs initiate osteogenesis at an earlier time point than AD-MSCs on graphene. Additionally, we found upregulated angiogenic markers in both MSCs sources, suggesting graphene could simultaneously attract the ingrowth of blood vessels in vivo. Finally, we identified several novel targets, including distal-less homeobox 5 (DLX5) and phosphate-regulating endopeptidase homolog, X-linked (PHEX). CONCLUSIONS: Overall, this study shows that graphene genetically supports differentiation of both AD-MSCs and BM-MSCs but may involve different signaling mechanisms to achieve osteogenesis. Data further demonstrates the lack of aberrant signaling due to cell-graphene interaction, strengthening the application of specific form and concentration of graphene nanoparticles in bone tissue engineering.

Dendritic cell biocompatibility of ether-based urethane films.

The use of synthetic materials for biomedical applications is ever expanding. One of the major requirements for these materials is biocompatibility, which includes prevention of immune system responses. Due to the inherent complexity of their structural composition, the polyurethane (PU) family of polymers is being used in a variety of medical applications, from soft and hard tissue scaffolds to intricate coatings on implantable devices. Herein, we investigated whether two polymer materials, D3 and D7, induced an immune response, measured by their effects on a dendritic cell (DC) line, JAWS II. Using a lactate dehydrogenase cytotoxicity assay and Annexin V/PI staining, we found that the PU materials did not induce cytotoxicity in DC cells. Using confocal microscopy, we also showed that the materials did not induce activation or maturation, as compared to positive controls. This was confirmed by looking at various markers, CD80, CD86, MHC class I, and MHC class II, via flow cytometry. Overall, the results indicated that the investigated PU films are biocompatible in terms of immunotoxicology and immunogenicity and show great promise for use in regenerative medicine.

Development and in vivo Assessment of a Rapidly Collapsible Anastomotic Guide for Use in Anastomosis of the Small Intestine: A Pilot Study Using a Swine Model.

Various conditions in human and veterinary medicine require intestinal resection and anastomosis, and complications from these procedures are frequent. A rapidly collapsible anastomotic guide was developed for small intestinal end-to-end anastomosis and was investigated in order to assess its utility to improve the anastomotic process and to potentially reduce complication rates. A complex manufacturing method for building a polymeric device was established utilizing biocompatible and biodegradable polyvinylpyrrolidone and polyurethane. This combination of polymers would result in rapid collapse of the material. The guide was designed as a hollow cylinder composed of overlaying shingles that separate following exposure to moisture. An in vivo study was performed using commercial pigs, with each pig receiving one standard handsewn anastomosis and one guide-facilitated anastomosis. Pigs were sacrificed after 13 days, at which time burst pressure, maximum luminal diameter, and presence of adhesions were assessed. Burst pressures were not statistically different between treatment groups, but in vivo anastomoses performed with the guide withstood 10% greater luminal burst pressure and maintained 17% larger luminal diameter than those performed using the standard handsewn technique alone. Surgeons commented that the addition of a guide eased the performance of the anastomosis. Hence, a rapidly collapsible anastomotic guide may be beneficial to the performance of intestinal anastomosis.

Functionalized Graphene Nanoparticles Induce Human Mesenchymal Stem Cells to Express Distinct Extracellular Matrix Proteins Mediating Osteogenesis.

PURPOSE: The extracellular matrix (ECM) labyrinthine network secreted by mesenchymal stem cells (MSCs) provides a microenvironment that enhances cell adherence, proliferation, viability, and differentiation. The potential of graphene-based nanomaterials to mimic a tissue-specific ECM has been recognized in designing bone tissue engineering scaffolds. In this study, we investigated the expression of specific ECM proteins when human fat-derived adult MSCs adhered and underwent osteogenic differentiation in the presence of functionalized graphene nanoparticles. METHODS: Graphene nanoparticles with 6-10% oxygen content were prepared and characterized by XPS, FTIR, AFM and Raman spectroscopy. Calcein-am and crystal violet staining were performed to evaluate viability and proliferation of human fat-derived MSCs on graphene nanoparticles. Alizarin red staining and quantitation were used to determine the effect of graphene nanoparticles on osteogenic differentiation. Finally, immunofluorescence assays were used to investigate the expression of ECM proteins during cell adhesion and osteogenic differentiation. RESULTS: Our data show that in the presence of graphene, MSCs express specific integrin heterodimers and exhibit a distinct pattern of the corresponding bone-specific ECM proteins, primarily fibronectin, collagen I and vitronectin. Furthermore, MSCs undergo osteogenic differentiation spontaneously without any chemical induction, suggesting that the physicochemical properties of graphene nanoparticles might trigger the expression of bone-specific ECM. CONCLUSION: Understanding the cell-graphene interactions resulting in an osteogenic niche for MSCs will significantly improve the application of graphene nanoparticles in bone repair and regeneration.

Quantitative ELISAs for serum soluble LHCGR and hCG-LHCGR complex: potential diagnostics in first trimester pregnancy screening for stillbirth, Down's syndrome, preterm delivery and preeclampsia.

BACKGROUND: Soluble LH/hCG receptor (sLHCGR) released from placental explants and transfected cells can be detected in sera from pregnant women. To determine whether sLHCGR has diagnostic potential, quantitative ELISAs were developed and tested to examine the correlation between pregnancy outcome and levels of serum sLHCGR and hCG-sLHCGR complex. METHODS: Anti-LHCGR poly- and monoclonal antibodies recognizing defined LHCGR epitopes, commerical anti-hCGbeta antibody, together with recombinant LHCGR and yoked hCGbeta-LHCGR standard calibrators were used to develop two ELISAs. These assays were employed to quantify serum sLHCGR and hCG-sLHCGR at first trimester human pregnancy. RESULTS: Two ELISAs were developed and validated. Unlike any known biomarker, sLHCGR and hCG-sLHCGR are unique because Down's syndrome (DS), preeclampsia and preterm delivery are linked to both low (less than or equal to 5 pmol/mL), and high (equal to or greater than 170 pmol/mL) concentrations. At these cut-off values, serum hCG-sLHCGR together with PAPP-A detected additional DS pregnancies (21%) which were negative by free hCGbeta plus PAPP-A screening procedure. Therefore, sLHCGR/hCG-sLHCGR has an additive effect on the current primary biochemical screening of aneuploid pregnancies. More than 88% of pregnancies destined to end in fetal demise (stillbirth) exhibited very low serum hCG-sLHCGR(less than or equal to 5 pmol/mL) compared to controls (median 16.15 pmol/mL, n = 390). The frequency of high hCG-sLHCGR concentrations (equal to or greater than 170 pmol/mL) in pathological pregnancies was at least 3-6-fold higher than that of the control, suggesting possible modulation of the thyrotropic effect of hCG by sLHCGR. CONCLUSIONS: Serum sLHCGR/hCG-sLHCGR together with PAPP-A, have significant potential as first trimester screening markers for predicting pathological outcomes in pregnancy.

[-2]Proenzyme prostate specific antigen is more accurate than total and free prostate specific antigen in differentiating prostate cancer from benign disease in a prospective prostate cancer screening study.

PURPOSE: Due to the limited specificity of prostate specific antigen for prostate cancer screening, there is an ongoing search for adjunctive biomarkers. Retrospective studies have suggested that an isoform of proenzyme prostate specific antigen called [-2]proenzyme prostate specific antigen may enhance the specificity of prostate specific antigen based screening. We examined the usefulness of this isoform in a prospective prostate cancer screening study. MATERIALS AND METHODS: From a population of 2,034 men undergoing prostate cancer screening we examined the relationship between the measurement of the [-2]isoform of proenzyme prostate specific antigen (p2PSA) and prostate cancer detection. Specifically we compared the usefulness of total prostate specific antigen, the ratio of free-to-total prostate specific antigen, the ratio of p2PSA-to-free prostate specific antigen, and a formula combining prostate specific antigen, free prostate specific antigen and p2PSA (the Beckman Coulter prostate health index or phi) to predict prostate cancer in men from the study undergoing prostate biopsy with a prostate specific antigen of 2.5 to 10 ng/ml and nonsuspicious digital rectal examination. RESULTS: Despite similar total prostate specific antigen (p = 0.88), percent free prostate specific antigen (p = 0.02) and %p2PSA (p = 0.0006) distinguished between positive and negative biopsy results. On ROC analysis %p2PSA (AUC 0.76) outperformed prostate specific antigen (AUC 0.50) and percent free prostate specific antigen (AUC 0.68) for differentiating between prostate cancer and benign disease. Setting the sensitivity at 88.5%, p2PSA led to a substantial improvement in specificity as well as positive and negative predictive values. The Beckman Coulter prostate health index (AUC 0.77) had the best overall performance characteristics. CONCLUSIONS: This is the first prospective study to our knowledge to demonstrate that p2PSA provides improved discrimination between prostate cancer and benign disease in screened men with a prostate specific antigen of 2.5 to 10 ng/ml and a negative digital rectal examination.

Reducing blood loss in open radical retropubic prostatectomy with prophylactic periprostatic sutures.

OBJECTIVE: To determine whether the placement of small-calibre, rapidly absorbed prophylactic periprostatic sutures before the mobilization of the prostate could reduce blood loss during open retropubic radical prostatectomy (RRP). PATIENTS AND METHODS: In 2007, during open RRP, we began placing prophylactic haemostatic sutures of 4-0 and 3-0 plain catgut in the anterior portions of the distal neurovascular bundles (NVBs) and lateral to the proximal NVBs and prostate pedicles before initiating the nerve-sparing dissection and mobilizing the prostate gland. To evaluate whether this reduced intraoperative blood loss, we compared estimated blood loss (EBL), non-autologous transfusion rates, and postoperative haemoglobin (Hb) levels between 100 consecutive patients treated immediately before and 100 consecutive patients treated immediately after the adoption of the prophylactic periprostatic suture technique. RESULTS: Before the use of prophylactic haemostatic sutures, the mean intraoperative blood loss was 1285 mL, and one patient (1%) received an intraoperative non-autologous transfusion. After the adoption of prophylactic sutures, the mean EBL was 700 mL (P < 0.001), and there were no transfusions. The mean Hb concentration the morning after RRP was 10.9 g/dL before and 11.8 g/dL after the initiation of prophylactic haemostatic sutures (P < 0.001). CONCLUSION: Prophylactic periprostatic haemostatic sutures significantly reduce intraoperative blood loss during open RRP.

Improved stage and grade-specific progression-free survival rates after radical prostatectomy in the PSA era.

OBJECTIVES: Since the initiation of prostate-specific antigen (PSA) screening, the progression-free survival (PFS) rates after radical prostatectomy have markedly improved. However, few studies have evaluated whether PFS has improved for stage and grade-matched patients. Our objective was to examine differences in PFS after radical prostatectomy between the pre-PSA era (before 1992) and the PSA era, controlling for tumor stage and grade. METHODS: From 1983 to 2003, 3456 men underwent radical prostatectomy by one surgeon. The 10-year PFS rates were calculated for each era and stratified by pathologic tumor stage and grade. Kaplan-Meier curves were generated to show biochemical PFS over time. RESULTS: The proportion of patients with pathologically organ-confined disease increased from 64% to 69%, consistent with stage migration. The PFS rate in the PSA era was 87%, 63%, 58%, and 31% versus 71%, 63%, 47%, and 19% in the pre-PSA era for Stage pT2R0, pT3R0, pT2-T3R1, and pT3c/N1 disease, respectively. The PFS rate stratified by Gleason grade in the PSA era was 84%, 63%, and 37% versus 66%, 49%, and 32% in the pre-PSA era for Gleason grade less than 7, 7, and 8 to 10, respectively. The 10-year PFS rate for organ-confined disease improved from 70% in the pre-PSA era to 86% in the PSA era. CONCLUSIONS: Patients treated with radical prostatectomy in the PSA era have improved survival outcomes when controlling for pathologic stage and grade. This is likely attributed to the earlier detection of cancer through PSA screening, better identification of patients amenable to curative therapy, and the effects of lead-time bias.

Pathological features after radical prostatectomy in potential candidates for active monitoring.

PURPOSE: There are numerous reports on the results of watchful waiting or active monitoring protocols for men with low volume, biopsy Gleason grade 6 or less prostate cancer. When counseling patients with low grade prostate cancer about treatment options, it is useful to know the results of surgical treatment in this population. MATERIALS AND METHODS: In a contemporary radical prostatectomy series there were 455 patients with biopsy Gleason grade 3 + 3 prostate cancer and information on the number of positive biopsy cores. Of these men 292 had low volume disease on the basis of 2 or fewer positive cores. RESULTS: Overall 245 of 292 men (84%) with low volume Gleason 3 + 3 prostate cancer on biopsy had organ confined disease. The Gleason score in the prostatectomy specimen was 7 or greater in 78 men (27%), 25 (8%) had extracapsular tumor extension and 29 (10%) had positive surgical margins. In these patients preoperative variables were not reliable predictors of adverse pathological features. CONCLUSIONS: More than a third of Gleason 3 + 3 tumors on biopsy were upgraded in the radical prostatectomy specimen or had other adverse pathological features. Our results suggest that low volume Gleason 3 + 3 prostate cancer is frequently under staged, and that immediate therapy with radical prostatectomy is associated with favorable outcomes.

Under diagnosis and over diagnosis of prostate cancer.

PURPOSE: We quantified the rates of over and under diagnosis of prostate cancer in 2 large patient cohorts during the last 15 years. MATERIALS AND METHODS: A total of 2,126 men with clinical stage T1c prostate cancer were treated with radical prostatectomy during 1 of the 3 periods 1989 to 1995, 1995 to 2001 and 2001 to 2005. The respective proportions of men with a tumor that met our criteria for over diagnosis (0.5 cm3 or less, confined to the prostate with clear surgical margins and no Gleason pattern 4 or 5) and under diagnosis (nonorgan confined, pathological stage T3 or greater, or positive surgical margins) were examined. RESULTS: The proportion of men with an over diagnosed tumor was 1.3% to 7.1%. The proportion with prostate cancer that was under diagnosed was 25% to 30%. An ancillary finding was that decreasing the prostate specific antigen threshold for biopsy from 4.0 to 2.5 ng/ml in the screened population resulted in a lower rate of under diagnosis from 30% to 26%, a higher rate of over diagnosis from 1.3% to 7.1% and an increase in the 5-year progression-free survival rate from 85% to 92%. Men who were 55 years or younger were significantly more likely to meet our criteria for over diagnosed cancer. CONCLUSIONS: Under diagnosis of prostate cancer continues to occur more frequently than over diagnosis. Lowering the prostate specific antigen threshold for recommending biopsy to 2.5 ng/ml resulted in a lower rate of under diagnosis and a higher progression-free survival rate.