RESUMO
The development of injectable hydrogels with natural biopolymers such as gelatin (Ge) and hyaluronic acid (Ha) is widely performed due to their biocompatibility and biodegradability. The combination of both polymers crosslinked with N-Ethyl-N'-(3-dimethyl aminopropyl) carbodiimide hydrochloride (EDC) can be used as an innovative dermal filler that stimulates fibroblast activity and increases skin elasticity and tightness. Thus, crosslinked Ge/Ha hydrogels with different concentrations of EDC were administered subcutaneously to test their efficacy in young and old rats. At higher EDC concentrations, the viscosity decreases while the particle size of the hydrogels increases. At all concentrations of EDC, amino and carboxyl groups are present. The histological analysis shows an acute inflammatory response, which disappears seven days after application. At one and three months post-treatment, no remains of the hydrogels are found, and the number of fibroblasts increases in all groups in comparison with the control. In addition, the elastic modulus of the skin increases after three months of treatment. Because EDC-crosslinked Ge/Ha hydrogels are biocompatible and induce increased skin tension, fibroblast proliferation, and de novo extracellular matrix production, we propose their use as a treatment to attenuate wrinkles and expression lines.
RESUMO
The half-time of cells and molecules used in immunotherapy is limited. Scaffolds-based immunotherapy against cancer may increase the half-life of the molecules and also support the migration and activation of leukocytes in situ. For this purpose, the use of gelatin (Ge)/hyaluronic acid (HA) scaffolds coupled to CpG and the tumor antigen MAGE-A5 is proposed. Ge and HA are components of the extracellular matrix that stimulate cell adhesion and activation of leucocytes; CpG can promote dendritic cell maturation, and MAGE-A5 a specific antitumor response. C57BL/6 mice were treated with Ge/HA/scaffolds coupled to MAGE-A5 and/or CpG and then challenged with the B16-F10 melanoma cell line. Survival, tumor growth rate and the immune response induced by the scaffolds were analyzed. Ge/HA/CpG and Ge/HA/MAGE-A5 mediated dendritic cell maturation and macrophage activation, increased survival, and decreased the tumor growth rate and a tumor parenchyma with abundant cell death areas and abundant tumor cells with melanin granules. Only the scaffolds coupled to MAGE-A5 induced the activation of CD8 T cells. In conclusion, Ge/HA scaffolds coupled to CpG or MAGE-A5, but not the mixture, can induce a successful immune response capable of promoting tumor cell clearance and increased survival.
RESUMO
Dendritic cells are antigen-presenting cells, which identify and process pathogens to subsequently activate specific T lymphocytes. To regulate the immune responses, DCs have to mature by the recognition of TLR ligands, TNFα or IFNγ. These ligands have been used as adjuvants to activate DCs in situ or in vitro, with toxic effects. It has been shown that some molecules affect the immune system, e.g., Masticadienonic acid (MDA) and 3α-hydroxy masticadienoic acid (3α-OH MDA) triterpenes naturally occurring in several medicinal plants, since they activate the nitric oxide synthase in macrophages and induce T lymphocyte proliferation. The DCs maturation induced by MDA or 3a-OH MDA was determined by incubating these cells with MDA or 3α-OH MDA, and their phenotype was afterwards analyzed. The results showed that only 3α-OH MDA was able to induce DCs maturation. When mice with melanoma were inoculated with DCs/3α-OH MDA, a decreased tumor growth rate was observed along with an extended cell death area within tumors compared to mice treated with DCs incubated with MDA. In conclusion, it is proposed that 3α-OH MDA may be an immunostimulant molecule. Conversely, it is proposed that MDA may be a molecule with anti-inflammatory properties.
Assuntos
Células Dendríticas/efeitos dos fármacos , Células Dendríticas/imunologia , Fatores Imunológicos/química , Fatores Imunológicos/farmacologia , Imunomodulação/efeitos dos fármacos , Triterpenos/química , Triterpenos/farmacologia , Animais , Biomarcadores , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Células Dendríticas/metabolismo , Modelos Animais de Doenças , Imunofenotipagem , Camundongos , Estrutura Molecular , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
The aim of dendritic cell (DC) vaccination in cancer is to induce tumor-specific effector T cells that may reduce and control tumor mass. Immunostimulants that could drive a desired immune response are necessary to be found in order to generate a long lasting tumor immune response. GK-1 peptide, derived from Taenia crassiceps, induces not only increase in TNFα, IFNγ, and MCP-1 production in cocultures of DCs and T lymphocytes but also immunological protection against influenza virus. Moreover, the aim of this investigation is the use of GK-1 as a bone marrow DCs (BMDCs) immunostimulant targeted with MAGE antigen; thus, BMDC may be used as immunotherapy against murine melanoma. GK-1 induced in BMDCs a meaningful increment of CD86 and IL-12. In addition, the use of BMDCs TNFα/GK-1/MAGE-AX induced the highest survival and the smallest tumors in mice. Besides, the treatment helped to increase CD8 lymphocytes levels and to produce IFNγ in lymph nodes. Moreover, the histopathological analysis showed that BMDCs treated with GK-1/TNFα and loaded with MAGE-AX induced the apparition of more apoptotic and necrotic areas in tumors than in mice without treatment. These results highlight the properties of GK-1 as an immunostimulant of DCs and suggest as a potential candidate the use of this immunotherapy against cancer disease.
Assuntos
Linfócitos T CD8-Positivos/imunologia , Vacinas Anticâncer , Células Dendríticas/imunologia , Proteínas de Helminto/metabolismo , Melanoma Experimental/terapia , Fragmentos de Peptídeos/metabolismo , Neoplasias Cutâneas/terapia , Animais , Antígenos de Neoplasias/metabolismo , Células da Medula Óssea/imunologia , Técnicas de Cultura de Células , Técnicas de Cocultura , Citocinas/metabolismo , Humanos , Ativação Linfocitária , Masculino , Melanoma Experimental/imunologia , Camundongos , Camundongos Endogâmicos C57BL , Transplante de Neoplasias , Oligopeptídeos/metabolismo , Neoplasias Cutâneas/imunologia , Carga TumoralRESUMO
Se presentan los resultados del tamizaje para eritroenzimopatías hereditarias en 707 recién nacidos a término con hiperbilirrubinemia (305 niñas y 402 varones), cuyo objetivo fue determinar su frecuencia relativa. Se tamizó por métodos fluorescentes para las eritroenzimopatías más frecuentes a saber: deficiencias de glucosa-6-fosfato deshidrogenasa (G-6-PD), piruvato cinasa (PC) y glucosa fosfatoisomerasa (GPI): estos son tres de los 14 errores congénitos del metabolismo del eritrocito claramente asociados con hemólisis. Se identificaron cuatro varones con deficiencia de G-6-PD y no se encontraron individuos con deficiencia de PC o GPI. Los resultados globales de éste y de estudios previos de nuestro grupo en una población de 2218 individuos sugieren que la frecuencia de la deficiencia de G-6-PD en varones recién nacidos con ictericia y/o hiperbilirrubinemia es de 1.08%. Se concluye que la deficiencia de G-6-PD como causa de hiperbilirrubinemia no es un problema de salud pública en la población estudiada; sin embargo, ya que 1% de los varones con ictericia y/o hiperbilirrubinemia neonatal tienen deficiencia de G-6-PD, se recomienda tomar en consideración este diagnóstico al evaluar a un neonato que presente anemia y/o hiperbilirrubinemia