Composite implants coated with biodegradable polymers prevent stimulating tumor progression

In this experiment we studied oncologic safety of model implants created using the solution blow spinning method with the use of the PURASORB PL-38 polylactic acid polymer and organic mineral filler which was obtained via laser ablation of a solid target made of dibasic calcium phosphate dihydrate. For this purpose the implant was introduced into the area of Wistar rats’ iliums, and on day 17 after the surgery the Walker sarcoma was transplanted into the area of the implant. We evaluated the implant’s influence on the primary tumor growth, hematogenous and lymphogenous metastasis of the Walker sarcoma. In comparison with sham operated animals the implant group demonstrated significant inhibition of hematogenous metastasis on day 34 after the surgery. The metastasis inhibition index (MII) equaled 94% and the metastases growth inhibition index (MGII) equaled 83%. The metastasis frequency of the Walker sarcoma in para aortic lymph nodes in the implant group was not statistically different from the control frequency; there was also no influence of the implant on the primary tumor growth noted. In case of the Walker sarcoma transplantation into the calf and the palmar pad of the ipsilateral limb to the one with the implant in the ilium, we could not note any attraction of tumor cells to the implant area, i.e. stimulation of the Walker sarcoma relapse by the implant. Thus, the research concluded that the studied implant meets the requirements of oncologic safety

Composite implants coated with biodegradable polymers prevent stimulating tumor progression

In this experiment we studied oncologic safety of model implants created using the solution blow spinning method with the use of the PURASORB PL-38 polylactic acid polymer and organic mineral filler which was obtained via laser ablation of a solid target made of dibasic calcium phosphate dihydrate. For this purpose the implant was introduced into the area of Wistar rats’ iliums, and on day 17 after the surgery the Walker sarcoma was transplanted into the area of the implant. We evaluated the implant’s influence on the primary tumor growth, hematogenous and lymphogenous metastasis of the Walker sarcoma. In comparison with sham operated animals the implant group demonstrated significant inhibition of hematogenous metastasis on day 34 after the surgery. The metastasis inhibition index (MII) equaled 94% and the metastases growth inhibition index (MGII) equaled 83%. The metastasis frequency of the Walker sarcoma in para aortic lymph nodes in the implant group was not statistically different from the control frequency; there was also no influence of the implant on the primary tumor growth noted. In case of the Walker sarcoma transplantation into the calf and the palmar pad of the ipsilateral limb to the one with the implant in the ilium, we could not note any attraction of tumor cells to the implant area, i.e. stimulation of the Walker sarcoma relapse by the implant. Thus, the research concluded that the studied implant meets the requirements of oncologic safety

Effect of small and radical surgical injury on the level of different populations of circulating tumor cells in the blood of breast cancer patients

Circulating tumor cells (CTCs) constitute a heterogeneous population. Some tumor cells are cancer stem cells (CSCs), while others are in the process of the epithelial-mesenchymal transition (EMT); however, most CTCs are neither stem cells nor in the EMT. This prospective study of 22 patients with nonspecific-type invasive carcinoma of the breast identified different populations of CTCs by flow cytometry in the blood of patients before biopsy, after biopsy and after surgical tumor removal without neoadjuvant chemotherapy. The results showed that minor surgical injury (biopsy) was accompanied by a significant increase in the blood levels of CTCs without signs of the EMT or stemness (Epcam+CD45-CD44-CD24-Ncadh-) and CTCs with signs of stemness and without signs of the EMT (Epcam+CD45-CD44+CD24-Ncadh-). Our results suggest that minor surgical injury to a tumor contributes to the release of CTCs into the bloodstream, including a population of stem cells

Биологические функции комплемента

One of the true basic resistance factors is complement. Main functions of it consist in bacterial lysis, bacterial opsonisation for phagocytosis. Alteration of lytic function for opsonic function depends upon macrophages. Complement functions at bacteriosis depend on phathogenesis features in infectious disease.Комплемент является одним из важнейших факторов резистентности организма. Система комплемента может принимать участие в различных эффекторных механизмах, прежде всего в лизисе (комплементарный киллинг) и опсонизации микроорганизмов. В переключении литической функции комплемента на опсоническую могут принимать участие макрофаги. Функции комплемента при бактериозах зависят от особенностей патогенеза инфекционного заболевания

Calcium phosphate coatings produced by radiofrequency magnetron sputtering method

Calcium phosphate coatings on titanium implants surface, produced by radio frequency (RF) magnetron sputtering method with hydroxyapatite solid target were investigated. It was found that produced coatings are calcium deficient compared to stoichiometric hydroxyapatite. The surface of the coatings is highly rough at the nanoscale and highly elastic. In vivo experiments on rats revealed that titanium implants with the calcium phosphate coatings do not cause negative tissue reaction after 6 months incubation period

Основная функция иммуноглобулинов класса М (IgM) – блокада преодоления бактериями гематотканевого барьера

Function of antibodies IgM consists in regulation of permeability of a blood-tissue barrier for microorganisms and its antigenes. IgM production in philogenesis and in onthogenesis is the independent form of the immune response. IgM block invasion extracell parasitizing bacteria in tissue. Granulema formation is a variant of IgM function in regulation of permeability blood-tissue barrier for intracell parasitizing bacteria.The suggested hypothesis allows to use new approaches in therapy of infections with obligatory bacteriemia.Функция иммуноглобулинов М (IgM) заключается в блокаде преодоления бактериями гематотканевого барьера. В фило­генезе и в онтогенезе образование IgM является самостоятельной формой иммунного ответа на проникновение в микроциркуляторное русло внеклеточно паразитирующих бактерий. Формирование гранулем является вариантом функции регуляции проницаемости гематотканевого барьера по отношению к внутриклеточно паразитирующим бактериям.Предлагаемая гипотеза позволяет использовать новые подходы в терапии инфекций с обязательной бактериемией

Clinically relevant morphological structures in breast cancer represent transcriptionally distinct tumor cell populations with varied degrees of epithelial-mesenchymal transition and CD44+CD24- stemness

Intratumor morphological heterogeneity in breast cancer is represented by different morphological structures (tubular, alveolar, solid, trabecular, and discrete) and contributes to poor prognosis; however, the mechanisms involved remain unclear. In this study, we performed 3D imaging, laser microdissection-assisted array comparative genomic hybridization and gene expression microarray analysis of different morphological structures and examined their association with the standard immunohistochemistry scorings and CD44+CD24- cancer stem cells. We found that the intratumor morphological heterogeneity is not associated with chromosomal aberrations. By contrast, morphological structures were characterized by specific gene expression profiles and signaling pathways and significantly differed in progesterone receptor and Ki-67 expression. Most importantly, we observed significant differences between structures in the number of expressed genes of the epithelial and mesenchymal phenotypes and the association with cancer invasion pathways. Tubular (tube-shaped) and alveolar (spheroid-shaped) structures were transcriptionally similar and demonstrated co-expression of epithelial and mesenchymal markers. Solid (large shapeless) structures retained epithelial features but demonstrated an increase in mesenchymal traits and collective cell migration hallmarks. Mesenchymal genes and cancer invasion pathways, as well as Ki-67 expression, were enriched in trabecular (one/two rows of tumor cells) and discrete groups (single cells and/or arrangements of 2-5 cells). Surprisingly, the number of CD44+CD24- cells was found to be the lowest in discrete groups and the highest in alveolar and solid structures. Overall, our findings indicate the association of intratumor morphological heterogeneity in breast cancer with the epithelial-mesenchymal transition and CD44+CD24- stemness and the appeal of this heterogeneity as a model for the study of cancer invasion

INTERACTION OF BIORESORBABLE COMPOSITE IMPLANTS MADE BY SOLUTION BLOW SPINNING WITH TISSUES

This work represents the results of the study of the surrounding tissues reaction to the implantation of bioresorbable implants formed by the solution blow spinning from polylactic acid and ultrafine calcium phosphate powders, depending on the time and place of implantation. Using scanning electron microscopy it is shown that implants formed from randomly interwoven fibers have interconnected open porosity. It was established that the addition of calcium phosphate ultrafine powders does not cause changes in the formed implants structure. Histological investigation of tissue specimens from the implantation site revealed a high ability of created implants to successful integration with surrounding tissue after 15 days from the moment of implantation. Complete or partial implant resorption with substitution by own tissues was registered at 90 days after implantation. It was established that implantation of composite bioresorbable implants on the ilium bone stimulates the osteogenic process better than the implantation on skull bone within the same period. It was defined that scarification of the outer cortical plate in implant contact points with bone tissue increases the implants ability to stimulate osteogenic process. It was shown that the composite implants filled with calcium phosphate dibasic dehydrate in ultrafine powder form have the largest ability to stimulate osteogenesis