Chitosan-based scaffolds for tissue regeneration: preparation and microstructure characterization

Scaffolds are porous three-dimensional supports, designed to mimic the extracellular environment and remain temporarily integrated into the host tissue while stimulating, at the molecular level, specific cellular responses to each type of body tissues. The major goal of the research work entertained herein was to study the microstructure of scaffolds made from chitosan (Ch), blends of chitosan and sodium alginate (Ch/NaAlg), blends of chitosan, sodium alginate and calcium chloride (Ch/NaAlg/CaCl2) and blends of chitosan, sodium alginate and hydroxyapatite (Ch/NaAlg/HA). Scaffolds possessing ideal physicochemical properties facilitate cell proliferation and greatly increase the rate of recovery of a damaged organ tissue. Using CT three-dimensional images of the scaffolds, it was observed that all scaffolds had a porosity in the range 64%-92%, a radius of maximum pore occurrence in the range 95m-260m and a permeability in the range 1×10-10-18×10-10 m2. From the results obtained, the scaffolds based on Ch, Ch/NaAlg and Ch/NaAlg/CaCl2 would be most appropriate both for the growth of osteoid and for bone tissue regeneration, while the scaffold made with a blend of Ch/NaAlg/HA, by possessing larger pores size, might be used as a support for fibrovascular tissue.Project funding by Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP, São Paulo, Brazil) (FAPESP Refs. No. 2012/21219-5, 2012/15651-4, 2013/03181-6, 2013/19300-4, and 2014/21122-0), is hereby gratefully acknowledged. This work received support from CNPq, National Council for Scientific and Technological Development – Brazil, in the form of Research Productivity (PQ) fellowships granted to Victor M. Balcão and Marco V. Chaud

Estudo da utilização de antimicrobianos e outros fármacos para distúrbios do trato respiratório em pacienteso de antimicrobianos e outros fármacos para distúrbios do trato respiratório em pacientes pediátricos hospitalizados

<p class="MsoNormal" style="margin: 0cm 0cm 0pt; line-height: normal; text-align: justify; mso-layout-grid-align: none;"> O tratamento das doenças respiratórias requerem a utilização de antibióticos, corticosteróides e broncodilatadores. Todavia é desejável que, na pediatria, estas medicações sejam restritas e se utilize uma via de administração confortável. O objetivo deste trabalho foi avaliar a utilização dos medicamentos do trato respiratório e antimicrobianos em pacientes pediátricos hospitalizados, por meio da análise de seus prontuários. Os dados foram coletados durante 120 dias, observando-se os medicamentos prescritos, as doses, as vias de administração e as medidas não farmacológicas prescritas. O critério de inclusão na pesquisa foi estar o paciente internado na pediatria, ter na prescrição um antimicrobiano ou medicamento para o trato respiratório. As análises dos 136 prontuários mostrou que 97,06% continham um antimicrobiano, sendo o mais prescrito ampicilina e o fenoterol e ipratrópio como broncodilatadores. Destaca-se que 21,35% das prescrições apresentaram dosagem abaixo do mínimo e em, 21,89% acima do máximo. Embora em 93,75% dos casos tenha havido prescrição de dieta por via oral, 70,59% dos pacientes tiveram prescrição de medicação por via intravenosa. Esses dados revelam o uso de doses subterapêuticas, prescrição excessiva de antimicrobianos e o uso freqüente da via parenteral que encarecem o tratamento, predispõem ao aparecimento de efeitos indesejáveis como superinfecção, prolongando o tempo de permanência no hospital. Palavras-chave: Posologia, criança hospitalizada, prescrição de medicamento, vias de administração, antimicrobianos, medicamentos do trato respiratório. </p&gt

Scaffolds and tissue regeneration: An overview of the functional properties of selected organic tissues

Tissue engineering plays a significant role both in the re-establishment of functions and regeneration of organic tissues. Success in manufacturing projects for biological scaffolds, for the purpose of tissue regeneration, is conditioned by the selection of parameters such as the biomaterial, the device architecture, and the specificities of the cells making up the organic tissue to create, in vivo, a microenvironment that preserves and further enhances the proliferation of a specific cell phenotype. To support this approach, we have screened scientific publications that show biomedical applications of scaffolds, biomechanical, morphological, biochemical, and hemodynamic characteristics of the target organic tissues, and the possible interactions between different cell matrices and biological scaffolds. This review article provides an overview on the biomedical application of scaffolds and on the characteristics of the (bio)materials commonly used for manufacturing these biological devices used in tissue engineering, taking into consideration the cellular specificity of the target tissue.Contract grant sponsor: FAPESP, Sao Paulo, Brazil; contract grant numbers: 2013/03181-6; 2013/19300-4Contract grant sponsor: FINEP Innovation and Research; contract grant number: 01.13.0286.0