Composite Zonal Scaffolds of Collagen I/II for Meniscus Regeneration.

The meniscus is divided into three zones according to its vascularity: an external vascularized red-red zone mainly comprising collagen I, a red-white interphase zone mainly comprising collagens I and II, and an internal white-white zone rich in collagen II. Known scaffolds used to treat meniscal injuries do not reflect the chemical composition of the vascular areas of the meniscus. Therefore, in this study, four composite zonal scaffolds (named A, B, C, and D) were developed and characterized; the developed scaffolds exhibited the main chemical components of the external (collagen I), interphase (collagens I/II), and internal (collagen II) zones of the meniscus.

Resection of a recurrent solid pseudopapillary neoplasm of the pancreas after duodenal sparing pancreaticoduodenectomy: A case report.

Introduction: Solid Pseudopapillary Neoplasm (SPN) is a rare pancreatic neoplasm with low malignant potential and a relative indolent course. Complete resection of the SPN is curative for most cases and has a high survival rate. Recurrences, though rare, can still occur despite adequate resection.

The Effect of Pore Directionality of Collagen Scaffolds on Cell Differentiation and In Vivo Osteogenesis.

Although many bone substitutes have been designed and produced, the development of bone tissue engineering products that mimic the microstructural characteristics of native bone remains challenging. It has been shown that pore orientation within collagen scaffolds influences bone matrix formation by the endochondral route. In addition, that the unidirectional orientation of the scaffolds can limit the growth of blood vessels.

Adjustable conduits for guided peripheral nerve regeneration prepared from bi-zonal unidirectional and multidirectional laminar scaffold of type I collagen.

Shortness of donor nerves has led to the development of nerve conduits that connect sectioned peripheral nerve stumps and help to prevent the formation of neuromas. Often, the standard diameters of these devices cannot be adapted at the time of surgery to the diameter of the nerve injured. In this work, scaffolds were developed to form filled nerve conduits with an inner matrix with unidirectional channels covered by a multidirectional pore zone.

Differential responses of endothelial cells on three-dimensional scaffolds to lipopolysaccharides from periodontopathogens.

Studies have been conducted on the pathogenicity of periodontopathogens in cultures of endothelial cells on two-dimensional (2D) polystyrene surfaces, where the monolayer formed is not exposed to proteins of the subendothelial matrix. In this work, we developed a culture system by seeding human coronary artery endothelial cells (HCAECs) onto three-dimensional (3D) scaffolds of collagen type I, a subendothelial protein. The inflammatory responses of the HCAEC monolayers, formed either on 3D scaffolds or directly on a 2D polystyrene plate, to lipopolysaccharide (LPS) from Aggregatibacter actinomycetemcomitans (Aa) and Porphyromonas gingivalis (Pg) were evaluated.

Evaluation of collagen type I scaffolds including gelatin-collagen microparticles and Aloe vera in a model of full-thickness skin wound.

Research on collagen type I scaffolds with Aloe vera is sparse. The aim of this work was to develop collagen type I scaffolds with gelatin-collagen microparticles and loaded with a dispersion of A. vera, to assess their performance as grafting material for healing of skin wounds.

Comparative evaluation of healing biomarkers in skin wound exudates using a nanobiosensor and histological analysis of full-thickness skin wounds grafted with multidirectional or unidirectional artificial dermis.

Analysis of factors that play a role on the healing process in exudates from skin wounds might shed light on the effect that grafted artificial tissue has in wound regeneration and repair. The first objective of this work was to standardize an optic surface plasmon resonance method based on self-assembled monolayers to quantify healing mediator factors (angiopoietin-2, epidermal growth factor, tumour necrosis factor-α, transforming growth factor-β1, and vascular endothelial growth factor) in wound exudates. Optimal conditions for self-assembling of alkanethiol monolayers, immobilization of antibodies antifactors, and regeneration of sensor surfaces were established.

Correction to: Comparison of healing of full-thickness skin wounds grafted with multidirectional or unidirectional autologous artificial dermis: differential delivery of healing biomarkers.

In the original article text presenting and discussing results shown in Fig. 6 omitted to mention that quantification of TGF-β2 and TGF-β3 was not included in Fig. 6a, c, e.

Comparison of healing of full-thickness skin wounds grafted with multidirectional or unidirectional autologous artificial dermis: differential delivery of healing biomarkers.

Cytokines, chemokines, and growth and remodeling factors orchestrate wound healing when skin damage occurs. During early stages, when the wound is still open, detection and quantification of these compounds might provide biomarkers of skin wound healing, which could aid to complete the scenario provided by clinical follow-up data and histological and histomorphometric analyses. This work assessed and compared the healing of full-thickness skin wounds grafted with artificial dermis made with autologous skin fibroblasts and unidirectional or multidirectional type I collagen scaffolds to test this hypothesis.

Two-dimensional and three-dimensional models for studying atherosclerosis pathogenesis induced by periodontopathogenic microorganisms.

Epidemiological studies have established a clinical association between periodontal disease and atherosclerosis. Bacteremia and endotoxemia episodes in patients with periodontitis appear to link these two diseases by inducing a body-wide production of cardiovascular markers. The presence of oral bacteria in atherosclerotic lesions in patients with periodontitis suggests that bacteria, or their antigenic components, induce alterations in the endothelium associated with atherosclerosis.

Multifactor analysis on the effect of collagen concentration, cross-linking and fiber/pore orientation on chemical, microstructural, mechanical and biological properties of collagen type I scaffolds.

This work evaluates the effect of processing variables on some physicochemical and mechanical properties of multi- and unidirectional laminar collagen type I scaffolds. The processing variables considered in this study included microstructure orientation (uni- and multidirectional fiber/pore controlled by freeze-drying methodology), cross-linking (chemical - using genipin and glutaraldehyde, and physical - using a dehydrothermal method), and collagen concentration (2, 5 and 8mg/ml). The biocompatibility of the scaffolds obtained in each of the evaluated manufacturing processes was also assessed.

Controlled release of an extract of Calendula officinalis flowers from a system based on the incorporation of gelatin-collagen microparticles into collagen I scaffolds: design and in vitro performance.

Aiming to develop biological skin dresses with improved performance in the treatment of skin wounds, acellular collagen I scaffolds were modified with polymeric microparticles and the subsequent loading of a hydroglycolic extract of Calendula officinalis flowers. Microparticles made of gelatin-collagen were produced by a water-in-oil emulsion/cross-linking method. Thereafter, these microparticles were mixed with collagen suspensions at three increasing concentrations and the resulting mixtures lyophilized to make microparticle-loaded porous collagen scaffolds.

Real-time quantification of proteins secreted by artificial connective tissue made from uni- or multidirectional collagen I scaffolds and oral mucosa fibroblasts.

Previously, we found that oral autologous artificial connective tissue (AACT) had a different protein secretion profile to that of clot-embedded AACT. Other oral mucosa substitutes, having different cell types and scaffolds, had dissimilar secretion profiles of proteins (including that for AACT) that influence healing outcome; thus, to ascertain the profiles of factors secreted by artificial tissue and whether they are influenced by their microstructure might help in understanding their bioactivity. An important component of tissue microstructure is the fiber orientation of the scaffold used for manufacturing it.

Neurotensin-loaded collagen dressings reduce inflammation and improve wound healing in diabetic mice.

Impaired wound healing is an important clinical problem in diabetes mellitus and results in failure to completely heal diabetic foot ulcers (DFUs), which may lead to lower extremity amputations. In the present study, collagen based dressings were prepared to be applied as support for the delivery of neurotensin (NT), a neuropeptide that acts as an inflammatory modulator in wound healing. The performance of NT alone and NT-loaded collagen matrices to treat wounds in streptozotocin (STZ) diabetic induced mice was evaluated.

Enterococcus faecalis internalization in human umbilical vein endothelial cells (HUVEC).

Initial Enterococcus faecalis-endothelial cell molecular interactions which lead to enterococci associating in the host endothelial tissue, colonizing it and proliferating there can be assessed using in vitro models. Cultured human umbilical vein endothelial cells (HUVEC) have been used to study other Gram-positive bacteria-cell interactions; however, few studies have been aimed at establishing the relationship of E. faecalis with endothelial cells.

In vitro and in vivo assessment of oral autologous artificial connective tissue characteristics that influence its performance as a graft.

Several studies have evaluated proteins secreted by fibroblasts comprising skin substitutes, finding that they are secreted in combinations and concentrations that promote wound healing. However, assessment of proteins secreted by oral fibroblasts forming a part of oral substitutes is scarce. In our previous work, collagen type-I scaffolds (CSs) and autologous artificial connective tissue (AACT) were produced and implanted in rabbit oral lesions, evidencing that AACT outperforms CS.

Development and preclinical evaluation of acellular collagen scaffolding and autologous artificial connective tissue in the regeneration of oral mucosa wounds.

This work assessed wound healing response in rabbit oral lesions grafted with autologous artificial connective tissue or acellular collagen scaffolds. Autologous artificial oral connective tissue (AACT) was produced using rabbit fibroblasts and collagen I scaffolds. Before implantation, AACT grafts were assayed to demonstrate the presence of fibroblasts and extracellular matrix components, as well as the expression of characteristic genes and secretion of chemokines, cytokines, and growth factors.

Determining the pharmacological activity of Physalis peruviana fruit juice on rabbit eyes and fibroblast primary cultures.

Purpose: The pharmacologic activity of compounds isolated from Physalis peruviana has been demonstrated. The use of this fruit juice for treating pterygium has been reported in Colombian traditional medicine. However, studies demonstrating the fruit juice's pharmacologic activity when used in this disease have not been published to date.

Effects of the foliar-applied protein "Harpin(Ea)" (messenger) on tomatoes infected with Phytophthora infestans.

The active ingredient in Messenger, is Harpin(Ea), a naturally occurring protein derived from Erwinia amylovora, a causal agent of fire blight. When Messenger is applied to a plant, the protein Harpin(Ea) binds foliar receptors to it. The receptors recognize the presence of Harpin(Ea), sending a signal that a pathogen is present, actually "tricking" the plant into thinking that it is under attack.

[Specific expression of inflammatory genes in macrophage subpopulations].

Macrophages serve as an effective component of innate immunity in their ability to recognize, engulf and kill potential pathogens. They also coordinate additional host responses by synthesizing a range of inflammatory mediators that can activate the adaptive immune response and establish protective immunity. Although they are a key component of mammalian defense system, macrophage activity is not always beneficial to the host.

[Primary cultures of human umbilical chord vein endothelial cells: a biological model for studying enterococcal infection mechanisms].

Although enterococcus bacteria are normal human intestinal flora, they rank as the third most common pathogen involved in hospital acquired infections. Generally, these bacteria are considered extracellular pathogens; however, an increasing number of reports indicate invasiveness to epithelial cell lines and macrophages. Despite their importance as nosocomial infection agents in patients suffering bacteremias and endocarditis, their interaction with endothelial cells has not been fully described.

[Isolation and characterization of macrophages-foam cells from aorta of hypercholesterolemic rabbit].

Evidence has accumulatd to support the hypothesis that atherosclerosis involves lipid imbalance as well as inflammatory responses mediated by macrophage and foam cells. These findings have been based on animal models. To rationalize animal use and to propose an alternative biological model, a technique was standardized for macrophage-foam cell isolation and culture.

Basic fibroblast growth factor decreases elastin gene transcription through an AP1/cAMP-response element hybrid site in the distal promoter.

Previous studies demonstrated that basic fibroblast growth factor (bFGF) decreases elastin gene transcription in pulmonary fibroblasts. In this study we pursue the identification of the element and the trans-acting factors responsible. Gel shift analyses show that bFGF increases protein binding to a sequence located at -564 to -558 base pairs (bp), which possesses homology to both AP1 and cAMP-response consensus elements yet displays a unique affinity for heterodimer binding.

Insulin-like growth factor-I regulates transcription of the elastin gene through a putative retinoblastoma control element. A role for Sp3 acting as a repressor of elastin gene transcription.

Previous studies have demonstrated that insulin-like growth factor-I (IGF-I) increases elastin gene transcription in aortic smooth muscle cells and that this up-regulation is accompanied by a loss of protein binding to the proximal promoter. Sp1 has been identified as one of the factors whose binding is lost, and in the present study we show that Sp3 binding is also abrogated by IGF-I, but in a selected manner. In functional analyses using Drosophila SL-2 cells, Sp1 expression can drive transcription from the elastin proximal promoter, while co-expression of Sp3 results in a repression of Sp1 activity.