Novel three-dimensional (3D) nanohydroxyapatite-PLGA scaffolds with high porosity was developed to better mimic mineral component and microstructure of natural bone. To perform a final assessment of this nanomaterial as a potential bone substitute, its toxicological profile was particularly investigated. Therefore, we performed a comet assay on human monocytes for in vitro genotoxicity investigation, and the systemic subchronic toxicity investigation on rats being per oral feed with exactly administrated extract quantities of the nano calcium hydroxyapatite covered with tiny layers of PLGA (ALBO-OS) for 120 days. Histological and stereological parameters of the liver, kidney, and spleen tissue were analyzed. Comet assay revealed low genotoxic potential, while histological analysis and stereological investigation revealed no significant changes in exposed animals when compared to controls, although the volume density of blood sinusoids and connective tissue, as well as numerical density and number of mitosis were slightly increased. Additionally, despite the significantly increased average number of the Ki67 and slightly increased number of CD68 positive cells in the presence of ALBO-OS, immunoreactive cells proliferation was almost neglected. Blood analyses showed that all of the blood parameters in rats fed with extract nanomaterial are comparable with corresponding parameters of no feed rats, taken as blind probe. This study contributes to the toxicological profiling of ALBO-OS scaffold for potential future application in bone tissue engineering.

The effects of a new material based on hydroxyapatite and calcium silicates, named ALBO-MPCA, were investigated on the liver, kidney and spleen. The material was administrated orally for 120 days in an in vivo model in Wistar rats, and untreated animals served as a control. Hematological and biochemical blood parameters were analyzed. Qualitative histological analysis of tissues, change in mitotic activity of cells, and histological characteristics was conducted, as well as quantitative stereological analysis of parenchymal cells, blood sinusoids, and connective tissues. Additionally, the protein expressions of Ki67 and CD68 markers were evaluated. Histological analysis revealed no pathological changes after the tested period. It showed the preservation of the architecture of blood sinusoids and epithelial cells and the presence of mitosis. Additionally, the significantly increased number of the Ki67 in the presence of ALBO-MPCA confirmed the proliferative effect of the material noticed by stereological analysis, while immunoreactive CD68 positive cells did not differ between groups. The study showed non-toxicity of the tested material based on the effects on the hematological, biochemical, and observed histological parameters; in addition, it showed evidence of its biocompatibility. These results could be the basis for further steps toward the application of tested materials in endodontics.

Diazepam-based drugs are widely used today in human treatment. Diazepam may be a primary drug aimed at treating neurological diseases or an associated drug in the treatment of other diseases in the purpose of symptomatic therapy. The sedative effect of diazepam characterizes it as a drug that people usually use on their own and without a doctor’s supervision. Directly, but also through influencing the nervous system, diazepam disrupts proper functioning of all body organs. The purpose of this paper was to examine the effects of diazepam on blood and cytohistological parameters of rats in an in vivo experiment. Mallory-Azan and immunochistochemical staining methods BLX-CX and Survivin tissues of liver, kidney and spleen of rats were used to achieve the set goal. Cytometric analysis of rats detected cells in apoptosis and measurements of stereological parameters were made using a system according to Cavalier’s principle. Results of analysis of hematological and histological parameters indicate a detrimental effect of diazepam on blood parameters, as well as on structure and functioning of the liver, kidneys and spleen of rats. This paper is a foundation for further detailed scientific research with the aim of elucidating all harmful effects that diazepam has on all organs in the body of rats. This data could serve as a starting point for future studies in clinical pharmacology on therapeutic protocols for usage of diazepam-based sedatives.

Background/Objectives: A novel 3D-printed, bioresorbable bone graft, made of nanohydroxyapatite (nHAP) covered by poly(lactide-co-glycolide) (PLGA), showed strongly expressed osteoinductive properties in our previous investigations. The current study examines its application in the dual regeneration of bone and cartilage by combining with nHAP gel obtained by nHAP enrichment with hydroxyethyl cellulose, sodium hyaluronate, and chondroitin sulfate. Methods: In the in vitro part of the study, the mitochondrial activity and osteogenic and chondrogenic differentiation of stem cells derived from apical papilla (SCAPs) in the presence of nHAP gel were investigated. For the in vivo part of the study, three rabbits underwent segmental osteotomies of the lateral condyle of the femur, and defects were filled by 3D-printed grafts customized to the defect geometry. Results: In vitro study revealed that nHAP gel displayed significant biocompatibility, substantially increasing mitochondrial activity and facilitating the osteogenic and chondrogenic differentiation of SCAPs. For the in vivo part of the study, after a 12-week healing period, partial resorption of the graft was observed, and lamellar bone tissue with Haversian systems was detected. Histological and stereological evaluations of the implanted grafts indicated successful bone regeneration, marked by the infiltration of new bone and cartilaginous tissue into the graft. The existence of osteocytes and increased vascularization indicated active osteogenesis. The hyaline cartilage near the graft showed numerous new chondrocytes and a significant layer of newly formed cartilage. Conclusions: This study demonstrated that tailored 3D-printed bone grafts could efficiently promote the healing of substantial bone defects and the formation of new cartilage without requiring supplementary biological factors, offering a feasible alternative for clinical bone repair applications.

Critical-sized bone defects pose significant challenges in orthopedic surgery. The introduction of 3D printing technology in bone grafting offers a promising solution by creating customized grafts that mimic the natural bone structure. This study aimed to reconstruct long-segment bone defects in the rabbit radius using a 3D-printed material composed of hydroxyapatite (HAP) and poly(lactide-co-glycolide) (PLGA), referred to as ALBO-OS, and to evaluate its potential to support bone healing without the use of stem cells or growth factors. Six rabbits underwent computed tomography scanning to create patient-specific 3D models of the radius. Custom-designed ALBO-OS implants were 3D-printed and used to fill segmental defects corresponding to one-third of the bone length in each rabbit, created by osteotomy. Over a 12-week observation period, graft integration, osteointegration, and overall bone regeneration were assessed through histological and histomorphometric analyses. The implanted scaffolds demonstrated encouraging bone healing, with significant bone regeneration observed within the defect areas. Histological evaluation revealed significant new bone formation and vascularization, with minimal inflammatory response. The findings demonstrated the potential of 3D-printed HAP/PLGA-based materials as a promising strategy for the reconstruction of large bone defects, eliminating the need for exogenous biological agents.

Chronic renal failure is a disease characterized by decreased kidney function andtherefore a change in haematological parameters in cats. In our work we analyzed the hematologicalparameters, course of renal disease and the lifespan of cats suffering from chronic renalinsufficiency. The aim of the study was to compare the haematological parameters of cats sufferingfrom CRF, fed a renal diet; cats suffering from CRF not fed a renal diet and cats that were completelyhealthy. Then, the importance of using CRF-approved food for diseased cats and the effectivenessof its application was determined.The study included a total of 60 cats, divided into three groups. The blood parameters of cats usedin our study were: erythrocytes, thrombocytes, total leucocytes, differential leukocyte, hemoglobinconcentration, hematocrit, MCV, MCH, MCHC, creatinine and urea. The study lasted for three yearsat the Veterinary Ambulance for pets "MIM COOP" Banja Luka.The study data were statistically analyzed using a T-test (p<0.05) and Pearson's correlationcoefficient. The results of our study show that the mean values of haematological parameters in thegroup of cats that did not use a renal diet for cats suffering from CRF were different statisticallyfrom other two groups of cats: the group that used a renal diet for cats suffering from CRF andcontrol groups of cats. Also, cats that used а renal diet have better quality of life and live longer thancats that did not receive this diet. Dietetic food recover kidneys of the cats suffering from CRF.