scholarly journals Physico-chemical and Histomorphometric Evaluation of Zinc-containing Hydroxyapatite in Rabbits Calvaria

2016 ◽  
Vol 27 (6) ◽  
pp. 717-726 ◽  
Author(s):  
Alinne Azevedo Pereira da Silva Suruagy ◽  
Adriana Terezinha Neves Novellino Alves ◽  
Suelen Cristina Sartoretto ◽  
José de Albuquerque Calasans-Maia ◽  
José Mauro Granjeiro ◽  
...  

Abstract The aim of this study was to characterize the physico-chemical properties and bone repair after implantation of zinc-containing nanostructured porous hydroxyapatite scaffold (nZnHA) in rabbits' calvaria. nZnHA powder containing 2% wt/wt zinc and stoichiometric nanostructured porous hydroxyapatite (nHA - control group) were shaped into disc (8 mm) and calcined at 550 °C. Two surgical defects were created in the calvaria of six rabbits (nZnHA and nHA). After 12 weeks, the animals were euthanized and the grafted area was removed, fixed in 10% formalin with 0.1 M phosphate buffered saline and embedded in paraffin (n=10) for histomorphometric evaluation. In addition, one sample from each group (n=2) was embedded in methylmethacrylate for the SEM and EDS analyses. The thermal treatment transformed the nZnHA disc into a biphasic implant composed of Zn-containing HA and Zn-containing β-tricalcium phosphate (ZnHA/βZnTCP). The XRD patterns for the nHA disc were highly crystalline compared to the ZnHA disc. Histological analysis revealed that both materials were biologically compatible and promoted osteoconduction. X-ray fluorescence and MEV-EDS of nZnHA confirmed zinc in the samples. Histomorphometric evaluation revealed the presence of new bone formation in both frameworks but without statistically significant differences (p>0.05), based on the Wilcoxon test. The current study confirmed that both biomaterials improve bone repair, are biocompatible and osteoconductive, and that zinc (2wt%) did not increase the bone repair. Additional in vivo studies are required to investigate the effect of doping hydroxyapatite with a higher Zn concentration.

Materials ◽  
2017 ◽  
Vol 10 (1) ◽  
pp. 33 ◽  
Author(s):  
Manabu Tanaka ◽  
Hisao Haniu ◽  
Takayuki Kamanaka ◽  
Takashi Takizawa ◽  
Atsushi Sobajima ◽  
...  

Materials ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1670 ◽  
Author(s):  
Wölfle-Roos JV ◽  
Katmer Amet B ◽  
Fiedler J ◽  
Michels H ◽  
Kappelt G ◽  
...  

Background: Uncemented implants are still associated with several major challenges, especially with regard to their manufacturing and their osseointegration. In this study, a novel manufacturing technique—an optimized form of precision casting—and a novel surface modification to promote osseointegration—calcium and phosphorus ion implantation into the implant surface—were tested in vivo. Methods: Cylindrical Ti6Al4V implants were inserted bilaterally into the tibia of 110 rats. We compared two generations of cast Ti6Al4V implants (CAST 1st GEN, n = 22, and CAST 2nd GEN, n = 22) as well as cast 2nd GEN Ti6Al4V implants with calcium (CAST + CA, n = 22) and phosphorus (CAST + P, n = 22) ion implantation to standard machined Ti6Al4V implants (control, n = 22). After 4 and 12 weeks, maximal pull-out force and bone-to-implant contact rate (BIC) were measured and compared between all five groups. Results: There was no significant difference between all five groups after 4 weeks or 12 weeks with regard to pull-out force (p > 0.05, Kruskal Wallis test). Histomorphometric analysis showed no significant difference of BIC after 4 weeks (p > 0.05, Kruskal–Wallis test), whereas there was a trend towards a higher BIC in the CAST + P group (54.8% ± 15.2%), especially compared to the control group (38.6% ± 12.8%) after 12 weeks (p = 0.053, Kruskal–Wallis test). Conclusion: In this study, we found no indication of inferiority of Ti6Al4V implants cast with the optimized centrifugal precision casting technique of the second generation compared to standard Ti6Al4V implants. As the employed manufacturing process holds considerable economic potential, mainly due to a significantly decreased material demand per implant by casting near net-shape instead of milling away most of the starting ingot, its application in manufacturing uncemented implants seems promising. However, no significant advantages of calcium or phosphorus ion implantation could be observed in this study. Due to the promising results of ion implantation in previous in vitro and in vivo studies, further in vivo studies with different ion implantation conditions should be considered.


Pharmaceutics ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 386
Author(s):  
Tung-Hu Tsai ◽  
Yu-Jen Chen ◽  
Li-Ying Wang ◽  
Chen-Hsi Hsieh

This study was performed to evaluate the interaction between conventional or high-dose radiotherapy (RT) and the pharmacokinetics (PK) of regorafenib in concurrent or sequential regimens for the treatment of hepatocellular carcinoma. Concurrent and sequential in vitro and in vivo studies of irradiation and regorafenib were designed. The interactions of RT and regorafenib in vitro were examined in the human hepatoma Huh-7, HA22T and Hep G2 cell lines. The RT–PK phenomenon and biodistribution of regorafenib under RT were confirmed in a free-moving rat model. Regorafenib inhibited the viability of Huh-7 cells in a dose-dependent manner. Apoptosis in Huh-7 cells was enhanced by RT followed by regorafenib treatment. In the concurrent regimen, RT decreased the area under the concentration versus time curve (AUC)regorafenib by 74% (p = 0.001) in the RT2 Gy × 3 fraction (f’x) group and by 69% (p = 0.001) in the RT9 Gy × 3 f’x group. The AUCregorafenib was increased by 182.8% (p = 0.011) in the sequential RT2Gy × 1 f’x group and by 213.2% (p = 0.016) in the sequential RT9Gy × 1 f’x group. Both concurrent regimens, RT2Gy × 3 f’x and RT9Gy × 3 f’x, clearly decreased the biodistribution of regorafenib in the heart, liver, lung, spleen and kidneys, compared to the control (regorafenib × 3 d) group. The concurrent regimens, both RT2Gy × 3 f’x and RT9Gy × 3 f’x, significantly decreased the biodistribution of regorafenib, compared with the control group. The PK of regorafenib can be modulated both by off-target irradiation and stereotactic body radiation therapy (SBRT).


2021 ◽  
Vol 95 ◽  
Author(s):  
E.S. El-Wakil ◽  
H.F. Abdelmaksoud ◽  
T.S. AbouShousha ◽  
M.M.I. Ghallab

Abstract Our work aimed to evaluate the possible effect of Annona muricata (Graviola) leaf extract on Trichinella spiralis in in vitro and in vivo studies. Trichinella spiralis worms were isolated from infected mice and transferred to three culture media – group I (with no drugs), group II (contained Graviola) and group III (contained albendazole) – then they were examined using the electron microscope. In the in vivo study, mice were divided into five groups: GI (infected untreated), GII (prophylactically treated with Graviola for seven days before infection), GIII (infected and treated with Graviola), GIV (infected and treated with albendazole) and GV (infected and treated with a combination of Graviola plus albendazole in half doses). Drug effects were assessed by adults and larvae load beside the histopathological small intestinal and muscular changes. A significant reduction of adult and larval counts occurred in treated groups in comparison to the control group. Histopathologically, marked improvement in the small intestinal and muscular changes was observed in treated groups. Also, massive destruction of the cultured adults’ cuticle was detected in both drugs. This study revealed that Graviola leaves have potential activity against trichinellosis, especially in combination with albendazole, and could serve as an adjuvant to anti-trichinellosis drug therapy.


2018 ◽  
Vol 75 (10) ◽  
pp. 4515-4529 ◽  
Author(s):  
Adriana C. Motta ◽  
Vitor de Miranda Fedrizzi ◽  
Maria Lourdes Peri Barbo ◽  
Eliana A. R. Duek

Author(s):  
Sabine Van Miert ◽  
Jan Creylman ◽  
Geert R. Verheyen

Engineered nanomaterials (ENM) have new or enhanced physico-chemical properties compared to their micron-sized counterparts, but may also have an increased toxic potential. Animal and in vitro testing are typically employed to investigate the toxic effects of (nano)materials. The sheer number of ENMs and their physico-chemical parameters make it impossible to only use in vivo and in vitro testing, and modelling technologies are also deployed to find relationships between ENM parameters and toxicity. A heterogenous dataset containing information on 192 nanoparticle endpoints was compiled within the MODENA COST-Action consortium. Here, the available data was mined to identify relationships between nanoparticle properties and cell-death as measured with four cytotoxicity assays. ANOVA, collinearity analyses and classification and regression trees gave indications on potential relations between the NP-properties and toxicity, but could not deliver a robust model. More information and datapoints are necessary to build well-validated models.


Author(s):  
SANGEETA CHOUDHURY ◽  
BLR MADHAVI

Objective: The aim of this work to formulate, evaluate and compare the effectiveness of herbal creams containing extract of reishi and tea tree oil for treating hirsutism. Methods: Herbal ingredients were authenticated. Cream base was initially formulated. Three formulations of herbal cream were prepared. Reishi ethanolic extract, tea tree oil, and combination of tea tree oil and reishi extract were added to the cream base and formulated cream were named as RHC, THC and RTC respectively. In vitro evaluations on herbal creams were done for the physicochemical characteristics. In vivo studies were carried out on female Swiss Albino mice for the activity against hair growth by topical application of cream to shaved skin. The histological and morphometric evaluation was carried out. Skin irritancy study was conducted. Results: The herbal creams showed desirable physicochemical properties like pH, viscosity and spreadability. Statistical analysis for the length of hair was performed by using one way ANOVA followed by DUNNET’S post hoc test where THC and RTC were found to be significant whereas RHC showed no significant reduction of hair growth compared to control. RTC showed a significant effect at p<0.05 and hair growth reduction was significant for THC at p<0.001 compared to the control group. RTC and THC showed mild to moderate reduction in the size of the hair follicles with a reduction of sebaceous gland size in the histological analysis. Conclusion: Topical application of herbal creams to mice showed that hair growth was fastest in group RHC and was slowest in group THC and intermediate with RTC. It can be concluded that these herbal actives can be used as an effective treatment against hirsutism. Within the study period, tea tree oil was found to be more effective than reishi extract and the combination product. Further formulation studies and in vivo studies need to be carried out on reishi to assess its effectiveness against hirsutism.


Materials ◽  
2019 ◽  
Vol 12 (7) ◽  
pp. 1186
Author(s):  
Lívia da Costa Pereira ◽  
Carlos Fernando de Almeida Barros Mourão ◽  
Adriana Terezinha Neves Novellino Alves ◽  
Rodrigo Figueiredo de Brito Resende ◽  
Marcelo José Pinheiro Guedes de Uzeda ◽  
...  

This study’s aim was to evaluate the biocompatibility and bioabsorption of a new membrane for guided bone regeneration (polylactic-co-glycolic acid associated with hydroxyapatite and β-tricalcium phosphate) with three thicknesses (200, 500, and 700 µm) implanted in mice subcutaneously. Scanning electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, and the quantification of carbon, hydrogen and nitrogen were used to characterize the physico-chemical properties. One hundred Balb-C mice were divided into 5 experimental groups: Group 1—Sham (without implantation); Group 2—200 μm; Group 3—500 μm; Group 4—700 μm; and Group 5—Pratix®. Each group was subdivided into four experimental periods (7, 30, 60 and 90 days). Samples were collected and processed for histological and histomorphometrical evaluation. The membranes showed no moderate or severe tissue reactions during the experimental periods studied. The 500-μm membrane showed no tissue reaction during any experimental period. The 200-μm membrane began to exhibit fragmentation after 30 days, while the 500-μm and 700-µm membranes began fragmentation at 90 days. All membranes studied were biocompatible and the 500 µm membrane showed the best results for absorption and tissue reaction, indicating its potential for clinical guided bone regeneration.


Author(s):  
Masataka Yoshikawa ◽  
T. Yabuuchi ◽  
N. Tsuji ◽  
Y. Shimomura ◽  
H. Hayashi ◽  
...  

Pharmaceutics ◽  
2019 ◽  
Vol 11 (6) ◽  
pp. 263 ◽  
Author(s):  
Maria Letizia Manca ◽  
Iris Usach ◽  
José Esteban Peris ◽  
Antonella Ibba ◽  
Germano Orrù ◽  
...  

New three-dimensionally-structured hybrid phospholipid vesicles, able to load clotrimazole in a high amount (10 mg/mL), were obtained for the first time in this work by significantly reducing the amount of water (≤10%), which was replaced with a mixture of glycerol and ethanol (≈90%). A pre-formulation study was carried out to evaluate the effect of both the composition of the hydrating medium and the concentration of the phospholipid on the physico-chemical properties of hybrid vesicles. Four different three-dimensionally-structured hybrid vesicles were selected as ideal systems for the topical application of clotrimazole. An extensive physico-chemical characterization performed using transmission electron microscopy (TEM), cryogenic transmission electron microscopy (cryo-TEM), 31P-NMR, and small-angle X-ray scattering (SAXS) displayed the formation of small, multi-, and unilamellar vesicles very close to each other, and was capable of forming a three-dimensional network, which stabilized the dispersion. Additionally, the dilution of the dispersion with water reduced the interactions between vesicles, leading to the formation of single unilamellar vesicles. The evaluation of the in vitro percutaneous delivery of clotrimazole showed an improved drug deposition in the skin strata provided by the three-dimensionally-structured vesicles with respect to the commercial cream (Canesten®) used as a reference. Hybrid vesicles were highly biocompatible and showed a significant antifungal activity in vitro, greater than the commercial cream Canesten®. The antimycotic efficacy of formulations was confirmed by the reduced proliferation of the yeast cells at the site of infection in vivo. In light of these results, clotrimazole-loaded, three-dimensionally-structured hybrid vesicles appear to be one of the most innovative and promising formulations for the treatment of candidiasis infections.


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