15 research outputs found
Designing topographically textured microparticles for induction and modulation of osteogenesis in mesenchymal stem cell engineering
Mesenchymal stem cells are the focus of intense research in bone development and regeneration. The potential of microparticles as modulating moieties of osteogenic response by utilizing their architectural features is demonstrated herein. Topographically textured microparticles of varying microscale features are produced by exploiting phase-separation of a readily soluble sacrificial component from polylactic acid. The influence of varying topographical features on primary human mesenchymal stem cell attachment, proliferation and markers of osteogenesis is investigated. In the absence of osteoinductive supplements, cells cultured on textured microparticles exhibit notably increased expression of osteogenic markers relative to conventional smooth microparticles. They also exhibit varying morphological, attachment and proliferation responses. Significantly altered gene expression and metabolic profiles are observed, with varying histological characteristics in vivo. This study highlights how tailoring topographical design offers cell-instructive 3D microenvironments which allow manipulation of stem cell fate by eliciting the desired downstream response without use of exogenous osteoinductive factors
Fibroblast Growth Factor 7 Releasing Particles Enhance Islet Engraftment and Improve Metabolic Control Following Islet Transplantation in Mice with Diabetes
open access articleTransplantation of islets in Type 1 diabetes is limited by poor islet engraftment into the liver, with 2-3 donor pancreases required per recipient. We aimed to condition the liver to enhance islet engraftment to improve long-term graft function. Diabetic mice received a non-curative islet transplant (n=400 islets) via the hepatic portal vein (HPV) with Fibroblast Growth Factor 7 loaded
galactoslyated poly(DL-lactide-co-glycolic acid) (FGF7-GAL-PLGA) particles; 26μm diameter particles specifically targeted the liver, promoting hepatocyte proliferation in short-term experiments: in mice receiving 0.1mg FGF7-GAL-PLGA particles (60ng FGF7) versus vehicle, cell proliferation was induced specifically in the liver with greater efficacy and specificity than subcutaneous FGF7 (1.25mg/kg ×2 doses; ~75μg FGF7). Numbers of engrafted islets and vascularisation were greater in liver sections of mice receiving islets and FGF7-GAL-PLGA particles versus mice receiving islets alone, 72 hours post-transplant. More mice (6 out of 8) that received islets and FGF7-GAL-PLGA particles normalised blood glucose concentrations by 30- days post-transplantation, versus 0 of 8 mice receiving islets alone with no evidence of increased proliferation of cells within the liver at this stage and normal liver function tests. This work shows liver targeted FGF7-GAL-PLGA particles achieve selective FGF7 delivery to the liver promoting islet engraftment to help normalise blood glucose levels with a good safety profile
Tratamientos Psicológicos Empíricamente Apoyados Para Adultos: Una Revisión Selectiva [Evidence-Based Psychological Treatments for Adults: A Selective Review]
Antecedentes: los tratamientos psicológicos han mostrado su efi cacia,
efectividad y efi ciencia para el abordaje de los trastornos mentales; no
obstante, considerando el conocimiento científi co generado en los últimos
años, no se dispone de trabajos de actualización en español sobre cuáles
son los tratamientos psicológicos con respaldo empírico. El objetivo fue
realizar una revisión selectiva de los principales tratamientos psicológicos
empíricamente apoyados para el abordaje de trastornos mentales en personas
adultas. Método: se recogen niveles de evidencia y grados de recomendación
en función de los criterios propuestos por el Sistema Nacional de Salud
de España (en las Guías de Práctica Clínica) para diferentes trastornos
psicológicos. Resultados: los resultados sugieren que los tratamientos
psicológicos disponen de apoyo empírico para el abordaje de un amplio
elenco de trastornos psicológicos. El grado de apoyo empírico oscila de bajo
a alto en función del trastorno psicológico analizado. La revisión sugiere
que ciertos campos de intervención necesitan una mayor investigación.
Conclusiones: a partir de esta revisión selectiva, los profesionales de la
psicología podrán disponer de información rigurosa y actualizada que les
permita tomar decisiones informadas a la hora de implementar aquellos
procedimientos psicoterapéuticos empíricamente fundamentados en
función de las características de las personas que demandan ayuda.
// Evidence-Based Psychological Treatments for Adults: A Selective Review. Background: Psychological treatments have shown their effi cacy,
effectiveness, and effi ciency in dealing with mental disorders. However,
considering the scientifi c knowledge generated in recent years, in the
Spanish context, there are no updating studies about empirically supported psychological treatments. The main goal was to carry out a selective
review of the main empirically supported psychological treatments for
mental disorders in adults. Method: Levels of evidence and degrees of recommendation were collected based on the criteria proposed by the Spanish National Health System (Clinical Practice Guidelines) for different
psychological disorders. Results: The results indicate that psychological
treatments have empirical support for the approach to a wide range of
psychological disorders. These levels of empirical evidence gathered range from low to high depending on the psychological disorder analysed.
The review indicates the existence of certain fi elds of intervention that
need further investigation. Conclusions: Based on this selective review,
psychology professionals will be able to have rigorous, up-to-date information that allows them to make informed decisions when implementing
empirically based psychotherapeutic procedures based on the characteristics of the people who require help
Effect of glycounits on the antimicrobial properties and toxicity behavior of polymers based on quaternized DMAEMA
Polymers with quaternary ammonium groups such as quaternized poly(2-(dimethylamino)ethyl methacrylate) (PDMAEMAQ) have been used as antimicrobial agents because of their demonstrated good antimicrobial activities against a huge number and types of microbes, although their cytotoxicity is also well known. In this work block copolymers based on PDMAEMAQ were synthesized containing hydrophobic segments of poly(butyl methacrylate) to improve the antimicrobial activity and glycomonomer units with the aim of decreasing the cytotoxicity of the polymers. Hydrophobic butyl methacrylate (BMA) blocks were chain extended by statistical and block copolymers of DMAEMA and 2-{[(D-glucosamin-2-N-yl)carbonylethyl methacrylate (HEMAGl) glycomonomer of different compositions. In order to find the balance between antimicrobial activity and cytotoxicity, the selectivity index of each polymer was obtained from minimum inhibitory concentrations (MIC) and white and red blood cells toxicity measurements
Functional surfaces obtained from emulsion polymerization using antimicrobial glycosylated block copolymers as surfactants
In this work, antimicrobial glycosylated block copolymers were successfully immobilized onto polymeric surfaces by using them as surfactants in butyl methacrylate emulsion polymerization. In particular several amphiphilic block copolymers of various compositions were employed, all consisting of a poly(butyl methacrylate) hydrophobic segment and a statistical copolymer containing quaternized trimethylaminoethyl methacrylate and 2-(D-glucosamin-2-N-yl)carbonylethyl methacrylate glycomonomer as a hydrophilic block. The influence of the antimicrobial polymeric surfactant structure and solid content on the emulsion polymerization was investigated in detail. It was demonstrated that the efficiency of the surfactant is highly dependent on the hydrophilic/hydrophobic balance; in general the surface-active properties get worse with an excess of hydrophilicity. Monodisperse and stable latexes stabilized with an antimicrobial polymeric surfactant were successfully obtained and then employed to form active films. The film formation process under thermal treatments was followed and confirmed by AFM. The surface functionality of the films was tested by analyzing the interaction of glycounits of the surface with Concanavalin A lectin by fluorescence spectroscopy. In addition, the antimicrobial capability of these films against Gram-positive bacteria and yeast was demonstrated whereas the leaching of the surfactants to the media was discarded. Graphical abstract: Functional surfaces obtained from emulsion polymerization using antimicrobial glycosylated block copolymers as surfactant
pH/NIR Light-Controlled Multidrug Release via a Mussel-Inspired Nanocomposite Hydrogel for Chemo-Photothermal Cancer Therapy
Catecholamine-induced electroless metallization of silver on silica@polymer hybrid nanospheres and their catalytic applications
10.1021/ie403840pIndustrial and Engineering Chemistry Research5383116-3124IECR