This work aimed to manufacture scaffolds from a hydrogel composed of a sodium alginate matrix with hydroxyapatite reinforcements using a 3D bioprinter, aiming at application in bone tissue regeneration. The alginate solution was prepared by dissolving sodium alginate at a concentration of 10% (w/v). Hydroxyapatite (HAp) was added to the solution at 2.5% and 5.0% (w/v) concentrations, followed by placing the samples in a container with a 1.0% (w/v) calcium chloride solution. The scaffolds were analyzed for HAp concentration and morphological characteristics, physicochemical properties, and biological response. The scaffolds show reproducibility and spectroscopic analyses confirm hydrogel formation and hydroxyapatite incorporation in the alginate matrix. The hydrophilic properties are compatible with scaffolds obtained through 3D printing made from polysaccharides, and the thermal analysis showed the expected behavior of these same materials. Preliminary findings indicated that scaffolds containing 2.5% (w/v) hydroxyapatite are inside cytotoxicity limit (66.4 ± 7.0%) towards canine E20 lineage cells. In contrast, scaffolds with 0% and 5.0% (w/v) hydroxyapatite were non-cytotoxic. Notably, the latter scaffold demonstrated enhanced cell proliferation, as anticipated, owing to the hydrophilic properties of alginate that enable easy and swift cell seeding, facilitating nutrient transport and cellular growth within the scaffold.

O serpin maspin, um supressor tumoral no câncer de mama foi descrito como inibidor de migração celular e indutor de adesão celular entre a membrana basal e a matriz extracelular resultando na inibição da metástase tumoral. Por outro lado, a alta expressão do maspin está relacionada com um mau prognóstico em outros tipos de câncer. Pouco se sabe sobre a expressão, regulação e função do maspin nos tumores mamários caninos. Neste estudo, foi demonstrada uma perda da expressão de maspin nas células mamárias malignas de cães quando comparadas com um pool de tecido mamário normal de cães, analisado por PCR quantitativa em tempo real. Houve uma expressão fraca maspin em preparações de tumores mamários malignos observadas por imuno-histoquímica. Também foi verificado que a expressão nuclear do maspin em tumores mamários caninos está relacionada a um bom prognóstico. Assim, o maspin pode ser utilizado como um marcador prognóstico nas neoplasias mamárias em cães.

The serpin maspin, a tumor suppressor in breast cancer was described as an inhibitor of cell migration and inducer of cell adhesion between the basement membrane and extracellular matrix resulting in inhibition of tumor metastasis. In contrast, overexpression of maspin is correlated with poor prognosis in other types of cancer. Little is known about expression, regulation and function of maspin in canine mammary tumors. It was demonstrated in this study, a loss of maspin expression in malignant canine mammary cells compared with a pool of normal canine mammary tissue, analyzed by quantitative real-time PCR; weak maspin expression in malignant canine mammary tumors were observed by immunohistochemistry. It was also demonstrated that a correlation with nuclear maspin expression and a good prognosis. It is suggested that maspin could be used as a prognostic marker in canine mammary neoplasia.

A e-caderina é uma molécula de adesão celular e a perda de sua expressão esta relacionada à invasão tumoral podendo indicar um prognóstico ruim nas neoplasias mamárias. A expressão dos marcadores de proliferação celular PCNA e especialmente o Ki-67, também têm mostrado forte valor prognóstico nesta classe tumoral. A expressão imuno-histoquímica destes marcadores foi relacionada com as características clinico-patológicas de 73 tumores removidos cirurgicamente de fêmeas caninas. Não houve correlação estatística entre estes marcadores e a morte por neoplasia, tempo de sobrevida e intervalo livre de doença. Entretanto, a perda da expressão da ecaderina e a forte expressão do Ki-67 (p=0,016) foram considerados estatisticamente significativos quando relacionados com o diagnóstico (p=0,032). Quando avaliados os fatores independentes, houve evidência de associação entre a perda de expressão da e-caderina e a alta expressão do PCNA com as mudanças no estado nutricional das cadelas (divididas em obesas, normais e caquéticas) (p=0,030); houve também evidência de associação entre a pseudociese e a expressão da e-caderina (p=0,021) e com a ulceração e a expressão do PCNA (p=0,035). A correlação significativa entre a expressão dos marcadores e estes, bem conhecidos fatores prognósticos usados individualmente ou em associação, sugere importante valor prognóstico destes marcadores nos tumores mamários caninos.

E-cadherin is a cell-cell adhesion molecule and low e-cadherin expression is related to invasiveness and may indicate a bad prognosis in mammary neoplasms. The expression of cell proliferation markers PCNA and especially Ki-67, has also proved to have a strong prognostic value in this tumor class. The expression of these markers was related to the clinical-pathological characteristics of 73 surgically removed mammary tumors in female dogs by immunohistochemistry. There was no statistical correlation between these markers and death by neoplasm, survival time and disease-free interval. However, the loss of e-cadherin expression and marked Ki-67 expression (p=0.016) were considered statistically significant for the diagnosis (p=0.032). When evaluated as independent factors, there was evidence of the relationship between the loss of e-cadherin expression and high PCNA expression with changes in the body status (divided into obese, normal and cachectic) of female dogs (p=0.030); there was also evidence of the relationship between pseudopregnancy and e-cadherin alone (p=0.021) and for ulceration and PCNA alone (p=0.035). The significant correlation between the markers expression and these well known prognostic factors used individually or in combination suggests their prognostic value in canine mammary tumors.