Rotary jet spinning (RJS) and electrospinning are techniques to obtain fibrous scaffolds. RJS is a simple method, which fabricates three-dimensional fibers by exploiting a high-speed rotating nozzle, creating a polymer jet which stretches until solidification, and does not require high voltage. In opposite, electrospinning technique needs the presence of an external electric field to create fiber from the polymeric jet solution. This article investigates both processes using two different biocompatible polymers: Poly(L-lactic acid) (PLLA) and Poly(ε-caprolactone) (PCL). Samples were characterized by scanning electron microscopy, thermogravimetric analysis, differential scanning calorimeter, and Fourier-transform infrared spectroscopy. Morphological observations showed the efficiency of both techniques in obtaining nanofibers. Thermal analyses of data indicate immiscible property of different blends and the total solvent evaporation. In vitro cytocompatibility test showed that RJS and electrospinning samples exhibited good cytocompatibility. Based on these results, it may be concluded that the fibers obtained with both technologies are non-cytotoxicity and with good biocompatibility, and might be suitable for applications as scaffold for cell growth.

Chitosan is soluble in diluted acid solutions and can easily form films by casting. However, residual acid neutralization should be performed for biomedical applications what may compromise physical and mechanical properties of the films. Thus, plasticizers can be added to improve these properties. The aim of this study was to characterize morphological, barrier and mechanical properties, besides evaluate the in vitro cytotoxicity of sorbitol-plasticized and NaOH-Na2CO3 neutralized chitosan membranes for skin substitute application. Scanning electron microscopy, X-ray diffraction, water vapor permeability and mechanical tests were carried out to characterize the obtained membranes. Moreover, Vero cells were used for in vitro cytotoxicity evaluation. In this paper, we report a non-cytotoxic sorbitol-plasticized chitosan membrane with desirable properties for skin substitution, such as flexibility, water vapor permeability and high percentage of elongation.

This study presents an innovative and original biomaterial designed to substitute for articular cartilage and mimic its mechanical behavior, including elastic cushioning and the characteristics of fiber-reinforced gel. The material was composed of polyurethane and bioglass microfiber 45S5. It was designed to present a tribological surface to the cartilage of the tibial plateau, and to convert over a functional gradient to an osteointegrable region for self-anchorage to the subchondral bone. The biomaterial samples showed no toxicity and promoted cell spreading. Subsequent in vivo studies in rabbits demonstrated the formation of a rigid structure similar to bone trabeculae in the distal region of the tribological surface of the implant. The tribological surface of the proximal region showed a fibrocartilaginous tissue with highly vascularized chondrocytes, thus validating the proposed concept for the design of the implant incorporating a functional gradient and auto-stability.

Embryo implantation is the process that results in attachment of the conceptus to the uterine wall. In this histochemical study, we investigated the early stage of embryo implantation in rats by morphological analysis and by the detection of total proteins and glycosaminoglycans using hematoxylin-eosin, toluidine blue at pH 4.0 (TB), and Xylidine Ponceau at pH 2.5 (XP). In non-pregnant females, the uterine layers could be clearly distinguished and showed the normal histology of the organ. In pregnant females, an increase in the number of cells and a reduction in the interstitial space were observed in the endometrium close to the implantation sites. The blastocyst was partially inserted in the endometrium, with the observation of the inner cells mass around the blastocyst cavity surrounded by trophoblastic cells. TB staining revealed mild metachromatic basophilia, which was more evident in the endometrial stroma around the implantation site. Histochemical staining with XP was also more intense in the stroma close to the site of implantation. On the other hand, histochemical staining with either TB or XP was more discrete at sites distant from the conceptus. This study demonstrated changes in the endometrial stroma in areas adjacent to the site of embryo implantation, with variations in glycosaminoglycans and proteins as demonstrated by the detection of anionic and cationic radicals, respectively.

La implantación embrionaria es el proceso que resulta en la unión del embrión a la pared uterina. En este estudio histoquímico, se determinó la fase inicial de implantación del embrión en ratas mediante el análisis morfológico y por la detección de proteínas totales y glicosaminoglicanos con hematoxilina-eosina, azul de toluidina a pH 4,0 (TB) y xilidina Ponceau a un pH de 2,5 (XP). En las hembras no preñadadas, las capas del útero pueden ser claramente distinguidas y mostraron la histología normal del órgano. En las hembras preñadas, se observa un incremento en el número de células y una reducción en el espacio intersticial del endometrio para cerrar los sitios de implantación. El blastocisto se implanta parcialmente en el endometrio, con presencia de masa de células internas en torno a la cavidad del blastocisto, rodeado por las células trofoblásticas. La tinción TB reveló leve basofilia metacromática, lo cual fue más evidente en el estroma endometrial alrededor del sitio de implantación. Tinción histoquímica con XP también fue más intensa próximo del estroma en el sitio de implantación. Por otro lado, la tinción histoquímica, ya sea con la tuberculosis o XP fue más leve en los lugares distantes del embrión. Este estudio demostró cambios en el estroma del endometrio en las zonas adyacentes al sitio de la implantación del embrión, con variaciones en glucosaminoglicanos y proteínas, como lo demuestra la detección de radicales aniónicos y catiónicos, respectivamente.

The aim of this study was to evaluate the effect of scaffolds native or polyanionic collagen matrix (submitted to alkaline treatment for 48 or 96 hours, PCM48 or PCM96, respectively) on the repair of osteoporosis bone fractures resulting from the gonadal hormone alterations caused by ovariectomy in rats undergoing hormone replacement therapy. The physical and mechanical characteristics of bone were analyzed. Macroscopic analysis revealed the absence of pathological alterations in the implanted areas. The percent mineral matter and bone mineral density of the femurs were lower in ovariectomized rats. The mechanical strength of newly formed bone was greater in the area receiving the PCM96 scaffolds compared to the area implanted with the native scaffolds. The PCM96 scaffold is the best choice for bone repair in animals with hormone deficiency since it promotes faster bone growth and good mechanical strength.

Poly (L-lactic acid) (PLLA) polymers are the most frequently used substrates for cell culture, tissue regeneration and orthopedic prostheses, mainly because of their atoxic characteristics and good biocompatibility. The objective of this study was to evaluate whether a higher density or different pore diameters (less than 45, 180-250, and 250-350 µm) would change the growth pattern of cultured cells. The cells were found to adhere to and spread over all PLLA scaffolds studied. The cells also showed similar proliferation on dense and porous PLLA scaffolds, except for PLLA scaffolds with a smaller pore diameter. The cytochemical data showed high metabolic cellular activity on the various substrates. Overall, the results indicated satisfactory cell growth and proliferation on the different PLLA scaffolds studied, especially for those with pore diameters of 180-250 µm and 250-350 µm.

OBJETIVOS: Perfluorocarbonos líquidos (PFCLs) são usados em cirurgias oftalmológicas de vítreo-retina. Os PFCLs podem causar reações inflamatórias, danos celulares e destruição da arquitetura normal da retina. Na tentativa de se evitar estes efeitos, foram desenvolvidos os alcanos semifluorinados (ASF). Este trabalho avaliou o uso potencial de um ASF, o perfluorohexiloctano (F6H8), como substituto do vítreo de longo prazo em condições controladas por meio de cultura celular. MÉTODOS: Foi feita análise da citotoxicidade indireta, na qual as células entram em contato apenas com elementos solúveis que pudessem ser eliminados pelo perfluorohexiloctano. Avaliou-se então a toxicidade direta, ou seja, a toxicidade mediada pelo contato, do perfluorohexiloctano por meio de microscopia eletrônica de varredura e a imunocitoquímica para a actina. Utilizou-se como controle, células em meio de cultura livre de qualquer tratamento, um controle positivo para toxicidade, que apresenta comprovado efeito tóxico às células, e um controle de peso que exercesse compressão mecânica similar à quantidade de perfluorohexiloctano utilizada no experimento. RESULTADO: Observou-se que o referido produto não apresenta toxicidade indireta. Os ensaios de toxicidade direta mostraram que as alterações celulares promovidas pelo perfluorohexiloctano eram similares àquelas exercidas pelo controle de peso e distintas do controle de toxicidade. CONCLUSÕES: O perfluorohexiloctano não apresenta toxicidade indireta e tem efeito mais compressivo do que tóxico sobre as células em cultura.

PURPOSE: Perfluorocarbon liquids (PFCLs) are used in vitreoretinal surgery. PFCLs may cause inflammatory reactions, cellular injury and destruction of the normal retinal architecture. In order to avoid these effects, semifluorinated alkanes (SFA) were developed. We assessed the potential use of an SFA known as perfluorohexiloctano (F6H8) as long-term vitreous replacement under controlled cell culture conditions. METHODS: We analyzed indirect cytotoxicity, where the cells only come into contact with soluble elements that can be eliminated by perfluorohexiloctano. We therefore analyzed direct toxicity (contact toxicity) of perfluorohexiloctano by means of scanning electronic microscopy and immunocytochemistry reagents for actin. Cells embedded in a treatment-free culture medium were used as control, a positive control for toxicity with an undeniably toxic effect on cells, and a weight control that produced a mechanical compression similar to the amount of perfluorohexiloctano used in the experiment. RESULTS: The indirect cytotoxicity test showed that F6H8 did not affect cell growth. Our direct toxicity tests showed that cellular alterations caused by perfluorohexiloctano were similar to those produced by the weight control and different from toxicity control. CONCLUSION: Perfluorohexiloctano does not present indirect toxicity and this product has a compressive rather than a toxic effect on cultured cells.