Loss of p53 drives neuron reprogramming in head and neck cancer.

The solid tumour microenvironment includes nerve fibres that arise from the peripheral nervous system1,2. Recent work indicates that newly formed adrenergic nerve fibres promote tumour growth, but the origin of these nerves and the mechanism of their inception are unknown1,3. Here, by comparing the transcriptomes of cancer-associated trigeminal sensory neurons with those of endogenous neurons in mouse models of oral cancer, we identified an adrenergic differentiation signature. We show that loss of TP53 leads to adrenergic transdifferentiation of tumour-associated sensory nerves through loss of the microRNA miR-34a. Tumour growth was inhibited by sensory denervation or pharmacological blockade of adrenergic receptors, but not by chemical sympathectomy of pre-existing adrenergic nerves. A retrospective analysis of samples from oral cancer revealed that p53 status was associated with nerve density, which was in turn associated with poor clinical outcomes. This crosstalk between cancer cells and neurons represents mechanism by which tumour-associated neurons are reprogrammed towards an adrenergic phenotype that can stimulate tumour progression, and is a potential target for anticancer therapy.

Phosphoprotein-based biomarkers as predictors for cancer therapy.

Disparities in cancer patient responses have prompted widespread searches to identify differences in sensitive vs. nonsensitive populations and form the basis of personalized medicine. This customized approach is dependent upon the development of pathway-specific therapeutics in conjunction with biomarkers that predict patient responses. Here, we show that Cdk5 drives growth in subgroups of patients with multiple types of neuroendocrine neoplasms. Phosphoproteomics and high throughput screening identified phosphorylation sites downstream of Cdk5. These phosphorylation events serve as biomarkers and effectively pinpoint Cdk5-driven tumors. Toward achieving targeted therapy, we demonstrate that mouse models of neuroendocrine cancer are responsive to selective Cdk5 inhibitors and biomimetic nanoparticles are effective vehicles for enhanced tumor targeting and reduction of drug toxicity. Finally, we show that biomarkers of Cdk5-dependent tumors effectively predict response to anti-Cdk5 therapy in patient-derived xenografts. Thus, a phosphoprotein-based diagnostic assay combined with Cdk5-targeted therapy is a rational treatment approach for neuroendocrine malignancies.

Rapamycin-Loaded Biomimetic Nanoparticles Reverse Vascular Inflammation.

RATIONALE: Through localized delivery of rapamycin via a biomimetic drug delivery system, it is possible to reduce vascular inflammation and thus the progression of vascular disease. OBJECTIVE: Use biomimetic nanoparticles to deliver rapamycin to the vessel wall to reduce inflammation in an in vivo model of atherosclerosis after a short dosing schedule. METHODS AND RESULTS: Biomimetic nanoparticles (leukosomes) were synthesized using membrane proteins purified from activated J774 macrophages. Rapamycin-loaded nanoparticles were characterized using dynamic light scattering and were found to have a diameter of 108±2.3 nm, a surface charge of -15.4±14.4 mV, and a polydispersity index of 0.11 +/ 0.2. For in vivo studies, ApoE-/- mice were fed a high-fat diet for 12 weeks. Mice were injected with either PBS, free rapamycin (5 mg/kg), or rapamycin-loaded leukosomes (Leuko-Rapa; 5 mg/kg) once daily for 7 days. In mice treated with Leuko-Rapa, flow cytometry of disaggregated aortic tissue revealed fewer proliferating macrophages in the aorta (15.6±9.79 %) compared with untreated mice (30.2±13.34 %) and rapamycin alone (26.8±9.87 %). Decreased macrophage proliferation correlated with decreased levels of MCP (monocyte chemoattractant protein)-1 and IL (interleukin)-b1 in mice treated with Leuko-Rapa. Furthermore, Leuko-Rapa-treated mice also displayed significantly decreased MMP (matrix metalloproteinases) activity in the aorta (mean difference 2554±363.9, P=9.95122×10-6). No significant changes in metabolic or inflammation markers observed in liver metabolic assays. Histological analysis showed improvements in lung morphology, with no alterations in heart, spleen, lung, or liver in Leuko-Rapa-treated mice. CONCLUSIONS: We showed that our biomimetic nanoparticles showed a decrease in proliferating macrophage population that was accompanied by the reduction of key proinflammatory cytokines and changes in plaque morphology. This proof-of-concept showed that our platform was capable of suppressing macrophage proliferation within the aorta after a short dosing schedule (7 days) and with a favorable toxicity profile. This treatment could be a promising intervention for the acute stabilization of late-stage plaques.

Electrospun electroconductive constructs of aligned fibers for cardiac tissue engineering.

Myocardial infarction remains the leading cause of death in the western world. Since the heart has limited regenerative capabilities, several cardiac tissue engineering (CTE) strategies have been proposed to repair the damaged myocardium. A novel electrospun construct with aligned and electroconductive fibers combining gelatin, poly(lactic-co-glycolic) acid and polypyrrole that may serve as a cardiac patch is presented. Constructs were characterized for fiber alignment, surface wettability, shrinkage and swelling behavior, porosity, degradation rate, mechanical properties, and electrical properties. Cell-biomaterial interactions were studied using three different types of cells, Neonatal Rat Ventricular Myocytes (NRVM), human lung fibroblasts (MRC-5) and induced pluripotent stem cells (iPSCs). All cell types showed good viability and unique organization on construct surfaces depending on their phenotype. Finally, we assessed the maturation status of NRVMs after 14 days by confocal images and qRT-PCR. Overall evidence supports a proof-of-concept that this novel biomaterial construct could be a good candidate patch for CTE applications.

Endosomal Escape of Polymer-Coated Silica Nanoparticles in Endothelial Cells.

Current investigations into hazardous nanoparticles (i.e., nanotoxicology) aim to understand the working mechanisms that drive toxicity. This understanding has been used to predict the biological impact of the nanocarriers as a function of their synthesis, material composition, and physicochemical characteristics. It is particularly critical to characterize the events that immediately follow cell stress resulting from nanoparticle internalization. While reactive oxygen species and activation of autophagy are universally recognized as mechanisms of nanotoxicity, the progression of these phenomena during cell recovery has yet to be comprehensively evaluated. Herein, primary human endothelial cells are exposed to controlled concentrations of polymer-functionalized silica nanoparticles to induce lysosomal damage and achieve cytosolic delivery. In this model, the recovery of cell functions lost following endosomal escape is primarily represented by changes in cell distribution and the subsequent partitioning of particles into dividing cells. Furthermore, multilamellar bodies are found to accumulate around the particles, demonstrating progressive endosomal escape. This work provides a set of biological parameters that can be used to assess cell stress related to nanoparticle exposure and the subsequent recovery of cell processes as a function of endosomal escape.

Ultrasound shear wave elastography effectively predicts integrity of ventral hernia repair using acellular dermal matrix augmented with platelet-rich plasma (PRP).

BACKGROUND: Complications of ventral hernia repair (VHR) may be investigated by computed tomography or ultrasound (US) but neither modality gives a quantifiable metric of repair quality short of identifying hernia recurrence. Platelet-rich plasma (PRP), a growth factor-rich autologous blood product, has been shown to improve incorporation of native tissue with bioprosthetics. In this study, we investigate the effect of PRP on the incorporation and mechanical integrity of a non-crosslinked porcine acellular dermal matrix (pADM) in a rodent model of VHR and the correlative ability of ultrasound shear wave elastography (US-SWE) to assess repair quality. METHODS: PRP was isolated from whole blood of Lewis rats. Twenty-eight Lewis rats underwent chronic VHR using either pADM alone or augmented with autologous PRP prior to non-invasive imaging assessment and specimen harvest at either 3 or 6 months. US-SWE was performed to estimate the Young's modulus prior to histological assessment and data from PRP-treated rodents were compared to controls. RESULTS: Implanted pADM was easily distinguishable by US-SWE imaging in all cases analyzed in this study. The mean Young's modulus measured was 1.78 times and 2.54 times higher in PRP-treated samples versus control at 3-month and 6-month time points respectively (p < 0.05). At 3 months, qualitative and quantitative histology revealed decreased inflammation and improved incorporation in PRP-treated samples along the implant/abdominal wall interface. At 6 months, the PRP cohort had no hernia recurrence and preserved ADM integrity from immunologic degradation, while all control animals suffered hernia recurrence (4/6) or extreme ADM thinning (2/6). CONCLUSION: This study confirms both the efficacy of PRP in augmenting VHR using pADM, as well as the reliability of US-SWE to non-invasively predict the quality of VHR. Although further human studies are necessary, this work supports PRP use to improve VHR outcomes and US-SWE potential for bedside non-invasive hernia characterization.

Characterization of ventral incisional hernia and repair using shear wave elastography.

BACKGROUND: To assess the integrity of hernia repair, imaging modalities such as computed tomography or ultrasound (US) are commonly used. Neither modality has currently the capacity to simultaneously image the mesh and quantify a prosthetic and surrounding tissue stiffness. In this pilot study, we hypothesize that US shear wave elastography (SWE) can be used to identify a polyester mesh and a biologic graft and to assess their stiffness noninvasively in a rat model of bridging hernia repair. METHODS: Lewis rats underwent hernia creation and repair with Parietex or Strattice at 30 d. After 3 mo, the animals were euthanized, and the Young's Modulus was measured using SWE. Three-dimensional reconstructions of the hernia pre- and post-repair were performed using in-house image processing algorithms. RESULTS: SWE was capable of accurate and real-time assessment and diagnosis of the hernia defects in vivo. Young's Modulus of Parietex meshes and Strattice grafts as estimated from the shear wave elastograms were found to be statistically different from each other (P < 0.05). Accurate three-dimensional reconstructions of the hernia defects pre- and post-repair were generated. CONCLUSIONS: In this study, we demonstrate the feasibility of using US SWE to detect ventral hernias and evaluate mesh repair in vivo. Our results indicate that the presence of a hernia and repair can be reliably visualized by SWE and three dimensionally reconstructed. Thus, this technique may provide both structural and functional information regarding the hernia and the repair.

Platelet-rich plasma: a biomimetic approach to enhancement of surgical wound healing.

Platelets are small anucleate cytoplasmic cell bodies released by megakaryocytes in response to various physiologic triggers. Traditionally thought to be solely involved in the mechanisms of hemostasis, platelets have gained much attention due to their involvement wound healing, immunomodulation, and antiseptic properties. As the field of surgery continues to evolve so does the need for therapies to aid in treating the increasingly complex patients seen. With over 14 million obstetric, musculoskeletal, and urological and gastrointestinal surgeries performed annually, the healing of surgical wounds continues to be of upmost importance to the surgeon and patient. Platelet-rich plasma, or platelet concentrate, has emerged as a possible adjuvant therapy to aid in the healing of surgical wounds and injuries. In this review, we will discuss the wound healing properties of platelet-rich plasma and various surgical applications.

Cross-linking of porcine acellular dermal matrices negatively affects induced neovessel formation using platelet-rich plasma in a rat model of hernia repair.

The degree of cross-linking within acellular dermal matrices (ADM) seems to correlate to neovascularization when used in ventral hernia repair (VHR). Platelet-rich plasma (PRP) enhances wound healing through several mechanisms including neovascularization, but research regarding its effect on soft tissue healing in VHR is lacking. We sought to study the effect of cross-linking on PRP-induced neovascularization in a rodent model of bridging VHR. We hypothesized that ADM cross-linking would negatively affect PRP-induced neovessel formation. PRP was extracted and characterized from pooled whole blood. Porcine cross-linked (cADM) and non-cross-linked ADMs (ncADM) were implanted in a rat model of chronic VHR after treatment with saline (control) or PRP. Neovascularization of samples at 2, 4, and 6 weeks was assessed by hematoxylin and eosin and immunohistochemical staining of CD 31. Adhesion severity at necropsy was compared using a previously validated scale. Addition of PRP increased neovascularization in both cADM and ncADM at 2- and 4-week time points but appeared to do so in a dependent fashion, with significantly greater neovascularization in the PRP-treated ncADMs compared to cADMs. Omental adhesions were increased in all PRP-treated groups. Results indicate that, for 2-week measurements when compared with the cADM group without PRP therapy, the mean change in neovascularization due to ncADM was 3.27 (Z = 2.75, p = 0.006), PRP was 17.56 (Z = 14.77, p < 0.001), and the combined effect of ncADM and PRP was 9.41 (Z = 5.6, p < 0.001). The 4-week data indicate that the average neovascularization change due to ncADM was 0.676 (Z = 0.7, p = 0.484), PRP was 7.69 (Z = 7.95, p < 0.001), and combined effect of ncADM and PRP was 5.28 (Z = 3.86, p < 0.001). These findings validate PRP as a clinical adjunct to enhance the native tissue response to implantable biomaterials and suggest that ncADM is more amenable than cADM to induced neovascularization. PRP use could be advantageous in patients undergoing VHR where poor incorporation is anticipated and early-enhanced neovascularization is desired.

Increased use of surgical energy promotes methicillin-resistant Staphylococcus aureus colonization in rabbits following open ventral hernia mesh repair.

BACKGROUND: Surgical energy has been widely implemented because of ease of use, effective hemostasis, and surgical dissection. Studies demonstrate its use to be an independent risk factor for postoperative wound infection. Methicillin-resistant Staphylococcus aureus (MRSA) is the most common bacteria found in postoperative mesh infection. No reports are available on the sequelae of surgical energy use for open ventral hernia repair (oVHR) with mesh. We hypothesized that increasing amounts of surgical energy will result in higher infectious burden after oVHR with composite multifilament polyester mesh (Parietex™ PCO). METHODS: New Zealand rabbits underwent bridging oVHR with Parietex™ PCO and were divided into three surgical treatment groups: (1) scalpel alone, (2) 120 J of energy, and (3) 600 J of energy. The bioprosthesis was then inoculated with 105 colony-forming units of MRSA. Rabbits were survived for 7 days with daily physical examination. Complete blood count, basci metabolic panel, and blood cultures were performed on postoperative days one, four, and seven. Surviving rabbits were killed, and meshes explanted for MRSA colony counts. RESULTS: Rabbits receiving the most surgical energy developed signs and symptoms of severe sepsis and wound necrosis within 24 h. In comparison, rabbits receiving no surgical energy had significantly less MRSA recovered from explanted mesh, significantly less bacteremia, and fewer adhesions. CONCLUSIONS: Increased use of surgical energy promoted greater colonization, exaggerated septic response to bacterial contamination, and more severe adhesions. In the absence of devitalized tissue, rabbits can effectively limit bacterial contamination. These findings support the surgical principles of proper tissue handling and highlight the detrimental effects of indiscriminant surgical energy usage, thus emphasizing the importance of programs such as Fundamental Use of Surgical Energy.

Ghee Butter as a Therapeutic Delivery System.

Solid lipid nanoparticles carrying a chemotherapeutic payload (i.e., temozolomide, TMZ) were synthesized using ghee, a clarified butter commonly used in traditional medicine and food products. Ghee solid lipid nanoparticles (GSLN) were characterized through dynamic light scattering, scanning electron microscopy, and UV-visible spectrometry. Formulations were generated with varying ratios of surfactant to lipid, resulting in a maximum TMZ entrapment efficiency of ˜70%. Optimal formulations were found to have an average size and polydispersity of ˜220 nm and 0.340, respectively. Release kinetics revealed TMZ-loaded GSLN (TMZ@GSLN) retained 10% of its pay-load at 2 h with ˜53% released in 5 h. Metabolic activity on human umbilical vein endothelial cells (HUVEC) revealed GSLN treatment resulted in an increase in viability following 3 d while treatment of glioblastoma LN-229 cells with TMZ@GSLN resulted in a significant decrease. Evaluation of diffusion of TMZ across a reconstructed HUVEC monolayer demonstrated TMZ@GSLN resulted in a significantly higher diffusion of drug when compared to free TMZ. This data suggests GSLN pose a promising delivery vehicle for TMZ-based therapeutics. Collectively, this data demonstrates GSLN exhibit favorable drug carrier properties with anti-proliferative properties in glioblastoma cancer cells.

Alterations of the Plasma Peptidome Profiling in Colorectal Cancer Progression.

Early detection of colorectal cancer (CRC) remains a challenge. It has been highlighted that the pathological alterations within an organ and tissues might be reflected in serum or plasma proteomic/peptidic patterns. The aim of the study was to follow the changes in the plasma peptides associated to colorectal cancer progression by mass spectrometry. This study included 27 adenoma, 67 CRC (n = 33 I-II stage and n = 34 III-IV stage), 23 liver metastasis from CRC patients and 34 subjects disease-free as controls. For plasma peptides analysis, samples purification was performed on the Nanoporous Silica Chips technology followed by matrix-assisted laser desorption/ionisation-time of flight analysis. Since the high complexity of the obtained dataset, multivariate statistical analysis, and discriminant pattern recognition were performed for study groups classification. Forty-four of 88 ionic species were successfully identified as fragments of peptides and proteins physiologically circulating in the blood and belonging to immune and coagulation systems and inflammatory mediators. Many peptides clustered into sets of overlapping sequences with ladder-like truncation clearly associated to proteolytic processes of both endo- and exoproteases activity. Comparing to controls, a different median ion intensity of the group-type fragments distribution was observed. Moreover, the degradation pattern obtained by proteolytic cleavage was different into study groups. This pattern was specific and characteristic of each group: controls, colon tumour disease (including adenoma and CRC), and liver metastasis, revealing a role as biomarker in early diagnosis and prognosis. Our findings highlighted peculiar changes in protease activity characteristic of CRC progression from pre-cancer lesion to metastatic disease. J. Cell. Physiol. 231: 915-925, 2016. © 2015 Wiley Periodicals, Inc.

Identification of a binding site of the human immunodeficiency virus envelope protein gp120 to neuronal-specific tubulin.

Human immunodeficiency virus-1 (HIV) promotes synaptic simplification and neuronal apoptosis, and causes neurological impairments termed HIV-associated neurological disorders. HIV-associated neurotoxicity may be brought about by acute and chronic mechanisms that still remain to be fully characterized. The HIV envelope glycoprotein gp120 causes neuronal degeneration similar to that observed in HIV-associated neurocognitive disorders subjects. This study was undertaken to discover novel mechanisms of gp120 neurotoxicity that could explain how the envelope protein promotes neurite pruning. Gp120 has been shown to associate with various intracellular organelles as well as microtubules in neurons. We then analyzed lysates of neurons exposed to gp120 with liquid chromatography mass spectrometry for potential protein interactors. We found that one of the proteins interacting with gp120 is tubulin ß-3 (TUBB3), a major component of neuronal microtubules. We then tested the hypothesis that gp120 binds to neuronal microtubules. Using surface plasmon resonance, we confirmed that gp120 binds with high affinity to neuronal-specific TUBB3. We have also identified the binding site of gp120 to TUBB3. We then designed a small peptide (Helix-A) that displaced gp120 from binding to TUBB3. To determine whether this peptide could prevent gp120-mediated neurotoxicity, we cross-linked Helix-A to mesoporous silica nanoparticles (Helix-A nano) to enhance the intracellular delivery of the peptide. We then tested the neuroprotective property of Helix-A nano against three strains of gp120 in rat cortical neurons. Helix-A nano prevented gp120-mediated neurite simplification as well as neuronal loss. These data propose that gp120 binding to TUBB3 could be another mechanism of gp120 neurotoxicity. We propose a novel direct mechanism of human immunodeficiency virus neurotoxicity. Our data show that the viral protein gp120 binds to neuronal specific tubulin ß-3 and blocks microtubule transport. Displacing gp120 from binding to tubulin by a small peptide prevents gp120-mediated neuronal loss. Our study reveals a novel target for developing adjunct therapies against viral infection that promotes neurocognitive disorders.

Nanocomposite Hydrogels as Platform for Cells Growth, Proliferation, and Chemotaxis.

The challenge of mimicking the extracellular matrix with artificial scaffolds that are able to reduce immunoresponse is still unmet. Recent findings have shown that mesenchymal stem cells (MSC) infiltrating into the implanted scaffold have effects on the implant integration by improving the healing process. Toward this aim, a novel polyamidoamine-based nanocomposite hydrogel is synthesized, cross-linked with porous nanomaterials (i.e., mesoporous silica nanoparticles), able to release chemokine proteins. A comprehensive viscoelasticity study confirms that the hydrogel provides optimal structural support for MSC infiltration and proliferation. The efficiency of this hydrogel, containing the chemoattractant stromal cell-derived factor 1α (SDF-1α), in promoting MSC migration in vitro is demonstrated. Finally, subcutaneous implantation of SDF-1α-releasing hydrogels in mice results in a modulation of the inflammatory reaction. Overall, the proposed SDF-1α-nanocomposite hydrogel proves to have potential for applications in tissue engineering.

Biomimetic Concealing of PLGA Microspheres in a 3D Scaffold to Prevent Macrophage Uptake.

Scaffolds functionalized with delivery systems for the release of growth factors is a robust strategy to enhance tissue regeneration. However, after implantation, macrophages infiltrate the scaffold, eventually initiating the degradation and clearance of the delivery systems. Herein, it is hypothesized that fully embedding the poly(d,l-lactide-co-glycolide acid) microspheres (MS) in a highly structured collagen-based scaffold (concealing) can prevent their detection, preserving the integrity of the payload. Confocal laser microscopy reveals that non-embedded MS are easily internalized; when concealed, J774 and bone marrow-derived macrophages (BMDM) cannot detect them. This is further demonstrated by flow cytometry, as a tenfold decrease is found in the number of MS engulfed by the cells, suggesting that collagen can cloak the MS. This correlates with the amount of nitric oxide and tumor necrosis factor-α produced by J774 and BMDM in response to the concealed MS, comparable to that found for non-functionalized collagen scaffolds. Finally, the release kinetics of a reporter protein is preserved in the presence of macrophages, only when MS are concealed. The data provide detailed strategies for fabricating three dimensional (3D) biomimetic scaffolds able to conceal delivery systems and preserve the therapeutic molecules for release.

Optimizing cell seeding and retention in a three-dimensional bioengineered cardiac ventricle: The two-stage cellularization model.

Current cell seeding techniques focus on passively directing cells to a scaffold surface with the addition of dynamic culture to encourage cell permeation. In 3D tissue engineered constructs, cell retention efficiency is dependent on the cell delivery method, and biomaterial properties. Passive cell delivery relies on cell migration to the scaffold surface; biomaterial surface properties and porosity determine cell infiltration capacity. As a result, cell retention efficiencies remain low. The development of an effective two-stage cell seeding technique, coupled with perfusion culture, provides the potential to improve cellularization efficiency, and retention. This study, uses a chitosan bioengineered open ventricle (BEOV) scaffold to produce a two-stage perfusion cultured ventricle (TPCV). TPCV were fabricated by direct injection of 10 million primary rat neonatal cardiac cells, followed by wrapping of the outer scaffold surface with a 3D fibrin gel artificial heart muscle patch; TPCV were perfusion cultured for 3 days. The average biopotential output was 1.731 mV. TPCV cell retention following culture was approximately 5%. Cardiac cells were deposited on the scaffold surface and formed intercellular connections. Histological assessment displayed localized cell clusters, with some dissemination, and validated the observed presence of intercellular and gap-junction interactions. The study demonstrates initial effectiveness of our two-stage cell delivery concept, based on function and biological metrics. Biotechnol. Bioeng. 2016;113: 2275-2285. © 2016 Wiley Periodicals, Inc.

Decreased hernia recurrence using autologous platelet-rich plasma (PRP) with Strattice™ mesh in a rodent ventral hernia model.

BACKGROUND: Recurrence after ventral hernia repair (VHR) remains a multifactorial problem still plaguing surgeons today. Some of the many contributing factors include mechanical strain, poor tissue-mesh integration, and degradation of matrices. The high recurrence rate witnessed with the use of acellular dermal matrices (ADM) for definitive hernia repair has reduced their use largely to bridging repair and breast reconstruction. Modalities that improve classic cellular metrics of successful VHR could theoretically result in improved rates of hernia recurrence; autologous platelet-rich plasma (PRP) may represent one such tool, but has been underinvestigated for this purpose. METHODS: Lewis rats (32) had chronic ventral hernias created surgically and then repaired with Strattice™ mesh alone (control) or mesh + autologous PRP. Samples were harvested at 3 and 6 months postoperatively and compared for gross, histologic, and molecular outcomes of: neovascularization, tissue incorporation, peritoneal adhesions, hernia recurrence, and residual mesh thickness. RESULTS: Compared to control at 3 months postoperatively, PRP-treated rats displayed significantly more neovascularization of implanted mesh and considerable upregulation of both angiogenic genes (vEGF 2.73-fold, vWF 2.21-fold) and myofibroblastic genes (αSMA 9.68-fold, FSP-1 3.61-fold, Col1a1 3.32-fold, Col31a1 3.29-fold). Histologically, they also showed enhanced tissue deposition/ingrowth and diminished chronic immune cell infiltration. Peritoneal adhesions were less severe at both 3 (1.88 vs. 2.94) and 6 months (1.63 vs. 2.75) by Modified Hopkins Adhesion Scoring. PRP-treated rats experienced decreased hernia recurrence at 6 months (0/10 vs. 7/10) and had significantly improved ADM preservation as evidenced by quantification of residual mesh thickness. CONCLUSIONS: PRP is an autologous source of pro-regenerative growth factors and chemokines uniquely suited to soft tissue wound healing. When applied to a model of chronic VHR, it incites enhanced angiogenesis, myofibroblast recruitment and tissue ingrowth, ADM preservation, less severe peritoneal adhesions, and diminished hernia recurrence. We advocate further investigation regarding PRP augmentation of human VHR.

Clinical predictive circulating peptides in rectal cancer patients treated with neoadjuvant chemoradiotherapy.

Preoperative chemoradiotherapy is worldwide accepted as a standard treatment for locally advanced rectal cancer. Current standard of treatment includes administration of ionizing radiation for 45-50.4 Gy in 25-28 fractions associated with 5-fluorouracil administration during radiation therapy. Unfortunately, 40% of patients have a poor or absent response and novel predictive biomarkers are demanding. For the first time, we apply a novel peptidomic methodology and analysis in rectal cancer patients treated with preoperative chemoradiotherapy. Circulating peptides (Molecular Weight <3 kDa) have been harvested from patients' plasma (n = 33) using nanoporous silica chip and analyzed by Matrix-Assisted Laser Desorption/Ionization-Time of Flight mass spectrometer. Peptides fingerprint has been compared between responders and non-responders. Random Forest classification selected three peptides at m/z 1082.552, 1098.537, and 1104.538 that were able to correctly discriminate between responders (n = 16) and non-responders (n = 17) before therapy (T0) providing an overall accuracy of 86% and an area under the receiver operating characteristic (ROC) curve of 0.92. In conclusion, the nanoporous silica chip coupled to mass spectrometry method was found to be a realistic method for plasma-based peptide analysis and we provide the first list of predictive circulating biomarker peptides in rectal cancer patients underwent preoperative chemoradiotherapy.

Platelet rich plasma enhances tissue incorporation of biologic mesh.

BACKGROUND: High recurrence rates because of poor tissue incorporation limit the use of acellular dermal matrices (ADMs) in ventral hernia repair (VHR). Platelet rich plasma (PRP) is a growth factor-rich autologous blood product known to enhance tissue repair through cellular proliferation and neovascularization. We sought to study the effect of PRP on a porcine noncross-linked ADM in an in vivo model of VHR. We hypothesized that PRP would enhance ADM-tissue incorporation in a rat model of VHR. METHODS: Whole blood was extracted from Lewis rats followed by PRP isolation and characterization. Using a rat model of VHR, a noncross-linked ADM (Strattice) was implanted and activated PRP applied before closure. Rats were sacrificed at 2, 4, and 6 wk. Immunohistochemical staining of CD 31 on endothelial cells was used to quantify neovascularization. Hematoxylin eosin stained tissues were measured to quantify tissue deposition. RESULTS: Platelet concentration of PRP was standardized to 1 × 10(6) platelets/µL. Grossly, vessels were more evident in PRP-treated rats. Immunohistochemical analysis demonstrated neovascularization was significantly greater in the PRP-treated ADMs at all time points. This increase in neovascularization correlated with an increased thickness of tissue deposition at 4 and 6 wk. CONCLUSIONS: PRP enhanced neovascularization and incorporation in a rat model of VHR. Enhanced neovascularization was associated with earlier and greater tissue deposition on the ADM. This suggests that PRP could be used as an adjunct to VHR in clinical scenarios where poor wound healing is anticipated and enhanced neovascularization and early tissue deposition are desired.

Infusion of iodine-based contrast agents into poly(p-dioxanone) as a radiopaque resorbable IVC filter.

To determine the feasibility of infusing resorbable inferior vena cava (IVC) filter with iodine-based contrast agents to produce a radiopaque, computed tomography (CT)-visible IVC filter. Infused poly(p-dioxanone) (PPDO) was obtained by incubating PPDO in different concentrations of 4-iodobenzoyl chloride (IBC) and 2,3,5-triiodobenzoic acid (TIBA). Characterizations of infused and nascent PPDO were done using elemental analysis, micro-CT, tensile strength analysis, scanning electron microscopy, and differential scanning calorimetry. Elemental analysis showed percentage loading of 1.07 ± 0.08 for IBC and 0.73 ± 0.01 for TIBA. The iodine loading remained the same within 2 weeks for TIBA but decreased to about 80 % with IBC when subjected to physiological conditions. Micro-CT images showed increased attenuation of the infused PPDO compared with the nascent PPDO. The Hounsfield unit values for infused and nascent sutures were 110 ± 40 and 153 ± 53 for PPDO infused with 2 mg/mL IBC and TIBA, respectively, but only 11.35 ± 2 for nascent PPDO. In contrast the HU for bone was 116 ± 37. Tensile strength analysis showed maximum loads of 1.01 ± 0.43 kg and 10.02 ± 0.54 kg for IBC and TIBA, respectively, and 10.10 ± 0.64 kg for nascent PPDO. Scanning electron microscopy showed that the morphology of the PPDO surface did not change after coating and preliminary cytotoxicity assay showed no killing effect on Hela cells. PPDO infused with a contrast agent is significantly more radiopaque than nascent PPDO on micro-CT imaging. This radiopacity could allow the position and integrity of infused resorbable IVC filter to be monitored while it is in place, thus increasing its safety and efficacy as a medical device.