Toxicological Profile of Nanostructured Bone Substitute Based on Hydroxyapatite and Poly(lactide-co-glycolide) after Subchronic Oral Exposure of Rats

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.

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Development of bronchiolar epithelium in rats

AJP Regulatory Integrative and Comparative Physiology ◽

10.1152/ajpregu.1986.250.5.r783 ◽

1986 ◽

Vol 250 (5) ◽

pp. R783-R788 ◽

Cited By ~ 1

Author(s):

G. D. Massaro ◽

D. Massaro

Keyword(s):

Secretory Granules ◽

Perinatal Period ◽

Volume Density ◽

Clara Cell ◽

Numerical Density ◽

Clara Cells ◽

Ciliated Cells ◽

Bronchiolar Epithelium ◽

Conducting Airways

We used ultrastructural and morphometric means to examine aspects of the regulation of the maturation of rat bronchiolar Clara cells and the development of the epithelium of small conducting airways in the perinatal period. We found the nuclear numerical density per cubed centimeter (Nvn) of Clara cells fell and the Nvn of ciliated cells increased from birth to age 60 days, the prenatal administration of a glucocorticosteroid (dexamethasone) to dams caused a 35% decrease in the Nvn of ciliated cells present at birth but did not alter the Nvn of Clara cells, the administration of dexamethasone to pups from postnatal days 1 to 6 did not alter the Nvn of bronchiolar Clara or ciliated cells present at age 7 days but did diminish the total number of lung cells as assessed by measurements of lung DNA, the administration of dexamethasone to dams from gestation days 18 to 20 or from gestation days 20 to 22 did not alter the volume density of Clara cell glycogen, secretory granules, rough endoplasmic reticulum, or mitochondria of pups at gestation day 21.5 or on the day of birth, and glucagon, epinephrine, and 8-bromoadenosine 3',5'-cyclic monophosphate resulted in a decrease of Clara cell glycogen when individually incubated in vitro for 4 h with bronchiolar tissue from rat fetuses 21.5 days of age.

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Genotoxic Impact of Aluminum-containing Nanomaterials in Human Intestinal and Hepatic Cells.

10.21203/rs.3.rs-72845/v1 ◽

2020 ◽

Author(s):

Pégah Jalili ◽

Sylvie HUET ◽

Agnès Burel ◽

Benjamin-Christoph Krause ◽

Caroline Fontana ◽

...

Keyword(s):

Oxidative Stress ◽

Dna Damage ◽

Comet Assay ◽

Oxidative Dna Damage ◽

Cell Transformation ◽

Oral Exposure ◽

No Production ◽

Ionic Form ◽

Ion Release

Abstract Background: Exposure of consumers to aluminum-containing nanomaterials (Al NMs) through numerous products is an area of concern for public health agencies since human health risks are not completely elucidated. In addition, the available data on the genotoxicity of Al2O3 and Al0 NMs are inconclusive or rare. In order to provide further information, the present study investigated the in vitro genotoxic potential of Al0 and Al2O3 NMs in intestinal and liver cell models since these tissues represent organs which would be in direct contact or could experience potential accumulation following oral exposure. Methods: Differentiated human intestinal Caco-2 and hepatic HepaRG cells were exposed to Al0 and Al2O3 NMs (0.03 to 80 µg/cm2) and the results were compared with those obtained with the ionic form AlCl3. Several methods, including H2AX labelling, the alkaline comet assay and micronucleus (MN) assays were used. Oxidative stress and oxidative DNA damage were assessed using High Content Analysis (HCA) and the formamidopyrimidine DNA-glycosylase -modified comet assay respectively. Moreover, carcinogenic properties of Al NMs were investigated through the cell transforming assay (CTA) in Bhas 42 cells.Results: The three forms of Al did not induce chromosomal damage when tested in the MN assay. Furthermore, no cell transformation was observed in Bhas 42 cells. However, although no production of oxidative stress was detected in HCA assays, Al2O3 NMs induced oxidative DNA damage in Caco-2 cells in the comet assay following a 24 h treatment. Considerable DNA damage was observed with Al0 NMs in both cell lines in the comet assay, although this was likely due to interference with these NMs. Finally, no genotoxic effects were observed with AlCl3. Conclusion: The slight effects observed with Al NMs are therefore not likely to be related to ion release in the cell media.

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Cytotoxicity investigation of a new hydroxyapatite scaffold with improved structural design

Srpski arhiv za celokupno lekarstvo ◽

10.2298/sarh1606280s ◽

2016 ◽

Vol 144 (5-6) ◽

pp. 280-287 ◽

Cited By ~ 1

Author(s):

Nikola Sjerobabin ◽

Bozana Colovic ◽

Milan Petrovic ◽

Dejan Markovic ◽

Slavoljub Zivkovic ◽

...

Keyword(s):

Bone Substitute ◽

Calcium Hydroxyapatite ◽

Bone Substitutes ◽

Sem Analysis ◽

Optimal Topology ◽

Cell Multiplication ◽

Porous Scaffolds ◽

High Porosity ◽

Polymer Foam ◽

Hydroxyapatite Scaffold

Introduction. Biodegradable porous scaffolds are found to be very promising bone substitutes, acting as a temporary physical support to guide new tissue regeneration, until the entire scaffold is totally degraded and replaced by the new tissue. Objective. The aim of this study was to investigate cytotoxicity of a synthesized calcium hydroxyapatite based scaffold, named ALBO-OS, with high porosity and optimal topology. Methods. The ALBO-OS scaffold was synthesized by the method of polymer foam template. The analysis of pore geometry and scaffold walls? topography was made by scanning electron microscope (SEM). The biological investigations assumed the examinations of ALBO-OS cytotoxicity to mouse L929 fibroblasts, using 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromidefor (MTT) and lactate dehydrogenase (LDH) tests and inverse phase microscopy. Results. The SEM analysis showed high porosity with fair pore distribution and interesting morphology from the biological standpoint. The biological investigations showed that the material is not cytotoxic to L929 cells. Comparison of ALBO-OS with Bio-Oss, as the global gold standard as a bone substitute, showed similar results in MTT test, while LDH test showed significantly higher rate of cell multiplication with ALBO-OS. Conclusion. The scaffold design from the aspect of pore size, distribution, and topology seems to be very convenient for cell adhesion and occupation, which makes it a promising material as a bone substitute. The results of biological assays proved that ALBO-OS is not cytotoxic for L929 fibroblasts. In comparison with Bio-Oss, similar or even better results were obtained.

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Morphometric analysis of peroxisomes in hepatocytes of alcohol-fed rats

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100157486 ◽

1989 ◽

Vol 47 ◽

pp. 1100-1101

Author(s):

D.C. Dominguez ◽

J.T. Ellzey

Keyword(s):

Caloric Intake ◽

Volume Density ◽

Controlled Study ◽

Control Group ◽

Numerical Density ◽

Cacodylate Buffer ◽

Paired Control ◽

Experimental Group ◽

Liver Peroxisomes ◽

Single Lesion

Peroxisomes which participate in 1ipid metabolism have been shown to be altered in several metabolic disorders and toxic conditions. In alcoholic liver disease, the single lesion most frequently found is lipid accumu1ation in hepatocytes. However, the mechanisms for this 1ipid accumu1ation are not clear. The occurrence of modifications of liver peroxisomes due to excess alcohol consumption has not been subjected to a controlled study. We utilized a combination of cytochemica1 and morphometrictechniques to study the size and number of liver peroxisomes in rats fed an alcohol-supplemented diet compared to those of matched-paired control animals.Male Sprague-Daw1ey rats (400-500 g) received a liquid diet. The experimental group (N = 5/group) was fed a diet containing 30% ethanol-derived calories (EDC) and the control group was fed an isocaloric diet to 30% EDC. A pair feeding procedure was employed to control for caloric intake. Small pieces of liver randomly selected, were fixed in 2.3% -glutaraldehyde in 0.1 M sodium cacodylate buffer, pH 7.2, incubated in a DAB medium and postfixed with. 2% aqueous osmium tetroxide. EM photographs were taken from sections of 3 tissue blocks from each sample (7,200X) with a Zeiss EM10-A (60 kV). With the use of a point counting method and a digital planimeter the volume density (Vv) and numerical density (Nv) were determined.

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Genotoxicity evaluation in vitro by comet assay of compound and crude extract obtained from P. Pubescens Benth.

Planta Medica ◽

10.1055/s-0035-1556214 ◽

2015 ◽

Vol 81 (11) ◽

Author(s):

VHS Souza ◽

A Paula OHohne ◽

R Grando ◽

N de Cassia de Almeida Queiroz ◽

GM Pastore ◽

...

Keyword(s):

Comet Assay ◽

Crude Extract

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Investigation of Oral Subacute Toxicity and In-Vitro Antioxidant Activity of Standardized Methanolic Extract of Quercus serrata Leaves

Current Bioactive Compounds ◽

10.2174/1573407216999201224150602 ◽

2020 ◽

Vol 16 ◽

Author(s):

Maibam Beebina Chanu ◽

Biseshwori Thongam ◽

Khumukcham Nongalleima ◽

Hans Raj Bhat ◽

Surajit Kumar Ghosh ◽

...

Keyword(s):

Nitric Oxide ◽

Antioxidant Activity ◽

Biochemical Parameters ◽

Methanolic Extract ◽

Reducing Power ◽

Quercus Serrata ◽

Control Group ◽

Blood Cell Count ◽

Toxicological Profile

Background: Quercus serrata Murray leaves have been used traditionally in the treatment of diabetes, dysmenorrhoea, inflammation and urinary tract infection. So, far no study had been reported on the toxicological profile and antioxidant properties of the plant. Objective: The present study was aimed to investigate the in-vivo toxicological profile and in-vitro antioxidant activities of the methanolic extract of standardized Quercus serrata leaves. Methods: Per-oral sub-acute toxicity study was performed in rats using three dose levels (200, 400 and 800 mg/kg b.w.) of the extract for 28-days. Control group received gum acacia suspended in water. Bodyweight was measured weekly. Biochemical parameters were analysed using the serum, the blood-cell count was done using whole blood. Pathological changes were also checked in highly perfused tissues. Further, in-vitro reducing power assay, nitric oxide scavenging assay, DPPH free-radical scavenging assay were performed to check the antioxidant activity of the extract. Results: There were no significant alterations in the blood-cell count and biochemical parameters analysed in the treatment group when compared with the normal control. Histopathology study of liver, kidney, pancreas, heart and brain revealed normal cellular architecture in the treatment groups alike the control group animals. Quercus serrata also showed a significant reduction of DPPH with IC50 4.48±0.254 µg/mL, in-vitro reducing power activity with IC50121.65±0.320 µg/mL and nitric oxide scavenging activity IC50 106.43±0.338 µg/mL. Conclusion: The above study showed that standardized methanolic extract of Quercus serrata leaves was safe after subacute oral administration in rats and has good antioxidant potential.

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In vitro effects of particulate bone substitute materials on the resorption activity of human osteoclasts

10.22203/ecm.v034a18 ◽

2017 ◽

Vol 34 ◽

pp. 291-306 ◽

Cited By ~ 5

Author(s):

G Russmueller ◽

◽

L Winkler ◽

R Lieber ◽

R Seemann ◽

...

Keyword(s):

Bone Substitute ◽

Bone Substitute Materials ◽

In Vitro Effects ◽

Substitute Materials ◽

Human Osteoclasts

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Validation of the in vitro comet assay for DNA cross-links and altered bases detection

Archives of Toxicology ◽

10.1007/s00204-021-03102-3 ◽

2021 ◽

Author(s):

Damián Muruzabal ◽

Julen Sanz-Serrano ◽

Sylvie Sauvaigo ◽

Bertrand Treillard ◽

Ann-Karin Olsen ◽

...

Keyword(s):

Comet Assay ◽

Human Health Risk ◽

High Sensitivity ◽

Dna Lesions ◽

Dna Glycosylase ◽

Vitro Assay ◽

Cytotoxic Compound ◽

Endonuclease Iii ◽

Cross Links

AbstractMechanistic toxicology is gaining weight for human health risk assessment. Different mechanistic assays are available, such as the comet assay, which detects DNA damage at the level of individual cells. However, the conventional alkaline version only detects strand breaks and alkali-labile sites. We have validated two modifications of the in vitro assay to generate mechanistic information: (1) use of DNA-repair enzymes (i.e., formamidopyrimidine DNA glycosylase, endonuclease III, human 8-oxoguanine DNA glycosylase I and human alkyladenine DNA glycosylase) for detection of oxidized and alkylated bases as well as (2) a modification for detecting cross-links. Seven genotoxicants with different mechanisms of action (potassium bromate, methyl methanesulfonate, ethyl methanesulfonate, hydrogen peroxide, cisplatin, mitomycin C, and benzo[a]pyrene diol epoxide), as well as a non-genotoxic compound (dimethyl sulfoxide) and a cytotoxic compound (Triton X-100) were tested on TK-6 cells. We were able to detect with high sensitivity and clearly differentiate oxidizing, alkylating and cross-linking agents. These modifications of the comet assay significantly increase its sensitivity and its specificity towards DNA lesions, providing mechanistic information regarding the type of damage.

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