Bio-Compatible Processing of LENSTM DepositedCo-Cr-W alloy for Medical Applications

Developing a Medicinal implants or devices is a challenging task for the researchers, right from the selection of materials, design, bio-compatibility and implantation to the host tissue. At every stage it requires proper care in processing of medical implants. In recent years the demand for medical implants had grown rapidly due to the awareness in the society. Major share of implants is used by younger people as they are active in sports, motor vehicle accidents leads to facture. Even older people also preferring to implants for ease of living. The commonly used implants are, prosthetic joints, knee replacement, dental, maxillofacial reconstructions etc.There is huge demand for the medical implants in coming years, presently a few bio-materials available for implant devices such as Ti-alloys, Stainless steel and Co-Cr-Mo alloys. There a scope to the researchers to develop a new alloy that are bio-compatible in nature and bring down the cost of the implant procedure to the needed patients. In this context additive manufacturing (AM) is an advanced manufacturing technology emerging as prominent technique in medical fields. Laser Engineered Net ShapingTM (LENS) is one such metal additive technique which provides fabrication of parts with the help of laser power, melts the powder alloy completely and builds parts layer by layer directly from the CAD model.In the present study, samples are fabricated from LENS process and carried the In-Vitro and In -Vivo bio-compatible tests as cytotoxicity and sub chronic toxicity to verify the toxicants release and their sustainability as the medical implants by the LENS deposited Co-Cr-W alloy samples. From the studies it is observed that the alloy samples show acceptable result. MTT assay demonstrate that cell viability is better in Osteoblast cells compared to the Fibroblast cells. Osteoblast cells show slightly more viable to the cell treatment on the samples during the experimental period. Sub chronic toxicity conclude that LENS deposited Co-Cr-W alloy is not toxic in all the rats studied herein and did not produce any toxic signs or evident symptoms. LENS deposited Co-Cr-W alloy did not cause any lethality or produce any relative body organs weight and haematological studies didn’t show adverse effects.

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Surface-Initiated Atom Transfer Polymerized Anionic Corona on Gold Nanoparticles for Anti-Cancer Therapy

Pharmaceutics ◽

10.3390/pharmaceutics12030261 ◽

2020 ◽

Vol 12 (3) ◽

pp. 261

Author(s):

Wei Mao ◽

Sol Lee ◽

Ji Un Shin ◽

Hyuk Sang Yoo

Keyword(s):

Gold Nanoparticles ◽

Transfection Efficiency ◽

Cancer Therapeutics ◽

Atom Transfer ◽

Layer By Layer ◽

Dependent Manner ◽

Metallic Particles ◽

Anti Cancer

Surface initiated atom transfer radical polymerization (SI-ATRP) documented a simple but efficient technique to grow a dense polymer layer on any surface. Gold nanoparticles (AuNPs) give a broad surface to immobilize sulfhyryl group-containing initiators for SI-ATRP; in addition, AuNPs are the major nanoparticulate carriers for delivery of anti-cancer therapeutics, since they are biocompatible and bioinert. In this work, AuNPs with a disulfide initiator were polymerized with sulfoethyl methacrylate by SI-ATRP to decorate the particles with anionic corona, and branched polyethyeleneimine (PEI) and siRNA were sequentially layered onto the anionic corona of AuNP by electrostatic interaction. The in vitro anti-cancer effect confirmed that AuNP with anionic corona showed higher degrees of apoptosis as well as suppression of the oncogene expression in a siRNA dose-dependent manner. The in vivo study of tumor-bearing nude mice revealed that mice treated with c-Myc siRNA-incorporated AuNPs showed dramatically decreased tumor size in comparison to those with free siRNA for 4 weeks. Furthermore, histological examination and gene expression study revealed that the decorated AuNP significantly suppressed c-Myc expression. Thus, we envision that the layer-by-layer assembly on the anionic brushes can be potentially used to incorporate nucleic acids onto metallic particles with high transfection efficiency.

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Clindamycin-loaded titanium prevents implant-related infection through blocking biofilm formation

Journal of Biomaterials Applications ◽

10.1177/08853282211051183 ◽

2021 ◽

pp. 088532822110511

Author(s):

Youbin Li ◽

Shaochuan Wang ◽

Shidan Li ◽

Jun Fei

Keyword(s):

Surface Modification ◽

Rat Model ◽

Biofilm Formation ◽

High Performance ◽

Bacterial Colonization ◽

Tissue Homogenate ◽

Tartrate Resistant Acid Phosphatase ◽

Layer By Layer

Implant-related infection is a disastrous complication. Surface modification of titanium is considered as an important strategy to prevent implant-related infection. However, there is no recognized surface modification strategy that can be applied in clinic so far. We explored a new strategy of coating. The clindamycin-loaded titanium was constructed by layer-by-layer self-assembly. The release of clindamycin from titanium was detected through high performance liquid chromatography. Different titanium was co-cultured with Staphylococcus aureus for 24 h in vitro, then the effect of different titanium on bacterial colonization and biofilm formation was determined by spread plate method and scanning electron microscopy. Cytotoxicity and cytocompatibility of clindamycin-loaded titanium on MC3T3-E1 cells were measured by CCK8. The antibacterial ability of clindamycin-loaded titanium in vivo was also evaluated using a rat model of osteomyelitis. The number of osteoclasts in bone defect was observed by tartrate-resistant acid phosphatase staining. Bacterial burden of surrounding tissues around the site of infection was calculated by tissue homogenate and colony count. Clindamycin-loaded titanium could release clindamycin slowly within 160 h. It reduced bacterial colonization by three orders of magnitude compare to control ( p < .05) and inhibits biofilm formation in vitro. Cells proliferation and adhesion were similar on three titanium surfaces ( p > .05). In vivo, clindamycin-loaded titanium improved bone healing, reduced microbial burden, and decreased the number of osteoclasts compared control titanium in the rat model of osteomyelitis. This study demonstrated that clindamycin-loaded titanium exhibited good biocompatibility, and showed antibacterial activity both in vivo and in vitro. It is promising and might have potential for clinical application.

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Evaluation of mutagenicity, genotoxicity and chronic toxicity of antiviral drug imidazolyl ethanamide pentandioic acid in in vitro and in vivo test systems

Journal of microbiology epidemiology immunobiology ◽

10.36233/0372-9311-180 ◽

2021 ◽

Vol 98 (5) ◽

pp. 548-557

Author(s):

E. A. Jain ◽

D. Pleimes ◽

A. A. Globenko

Keyword(s):

Oral Administration ◽

Chromosomal Aberrations ◽

Ames Test ◽

Chronic Toxicity ◽

Micronucleus Test ◽

Human Lymphocytes ◽

Antiviral Drug ◽

Systemic Exposure

Introduction. The antiviral properties of imidazolyl ethanamide pentandioic acid (IPA), the active compound of the drug product, has been proven in various experimental models. However, the literature data on the toxicological properties of IPA are limited.Purpose. To evaluate mutagenic and genotoxic properties in in vitro and in vivo models, as well as to study the toxicity of IPA following chronic oral administration to rats and dogs.Materials and methods. Mutagenic and genotoxic properties of IPA were assessed using the Ames test, the test of chromosomal aberrations in human lymphocytes, and the micronucleus test in rats. The chronic toxicity of IPA was studied in Sprague Dawley rats and beagle dogs of both sexes, to which IPA was administered orally at doses of 30-300 mg/kg/day for 26 and 39 weeks, respectively.Results and discussion. In the Ames test, the addition of IPA up to the maximum dose (5000 mcg/plate) did not result in the increase in the number of revertant colonies. At a concentration of up to 5000 mcg/ml, IPA did not cause chromosomal aberrations in human leukocytes. At doses doses ≤ 2000 mg/kg, IPA did not increase the amount of micronuclei in the bone marrow of rats. In chronic experiments, animals tolerated the administration of IPA well: the dose without an observed effect (NOEL) for rats and dogs was 300 mg/kg/day.Conclusion. IPA did not show mutagenic and genotoxic properties in standard in vitro and in vivo tests. With chronic oral administration to rats and dogs, NOEL IPA equal to 300 mg/kg/day provided a systemic exposure that was 8-10 and 41-65 times higher than that in humans, respectively. The results obtained allow us to consider the safety profile of the prolonged use in humans as favorable.

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Flavonoids content of 70% methanolic extract of Erucaria pinnata (Viv.) and its effect as anticancer and antiangiognic: in vitro, in vivo and docking study

International Journal of Research in Pharmaceutical Sciences ◽

10.26452/ijrps.v11i1.1779 ◽

2020 ◽

Vol 11 (1) ◽

pp. 25-38

Author(s):

Nadia I. Zakhary ◽

Emad E.H. El Gemeie ◽

Adel K. Youssef ◽

Marwa Abdel-salam Ibrahim Metwaly

Keyword(s):

Cytotoxic Activity ◽

Methanolic Extract ◽

Coastal Region ◽

Experimental Period ◽

Docking Study ◽

Gamma Glutamyl Transferase ◽

Histopathological Studies ◽

Glutamyl Transferase

Erucaria pinnata (Viv.) is a wild annual plant growing in North-Western Coastal Region in Egypt. This study reports for the first time the cytotoxic activity of different extracts of Erucaria pinnata plant against HEP-G2 cell line. The 70% methanolic extract (E1) recorded the best potent cytotoxic activity (IC50=13.6 µg/ml), so we analysis the flavonoids constituent of this extract using HPLC, which show that our extract is rich with important flavonoids compounds (rutin, quercetin, leutolin, etc.). We evaluated its antitumor activity against hepatocellular carcinoma (HCC) induced by diethylnitrosamine (DEN) (200mg/Kg. b.wt., i.p, single dose) after two weeks, animals received carbontetrachloride (CCl4) (3ml/Kg. b.wt., SC, once a week for 6 weeks) and the experiment continued for 44 weeks in rats. After the experimental period, the administration of DEN/CCl4 showed significant increase in the levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), total bilirubin, gamma-glutamyl transferase (γGT) and significant decrease in the levels of total proteins and albumin content in the serum with reduction in the liver antioxidants, including superoxide dismutase (SOD) and catalase (CAT). This was accompanied by increases in serum specific tumor markers (AFP). The 70% methanolic plant extract (E1) was orally administrated (400mg/kg/day respectively) for the whole study period, and it showed a significant improvement at the different biological liver functions, remodeled the antioxidant enzymes activity and down-regulated the serum AFP. All these findings were confirmed by histopathological studies of the liver samples obtained from all groups. In addition, we evaluated its antiangeogenic activity by docking study against VEGFR-2 tyrosine kinase after it showed an ability to inhibit the VEGFR-2 expression in vitro and inhibit the concentration of VEGF-A in vivo. The hepatoprotective effect of our extract was attributed to its antioxidant and antiangeogenic activity.

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The Fundamental Comparison of Zn–2Mg and Mg–4Y–3RE Alloys as a Perspective Biodegradable Materials

Materials ◽

10.3390/ma12223745 ◽

2019 ◽

Vol 12 (22) ◽

pp. 3745 ◽

Cited By ~ 3

Author(s):

Kubásek ◽

Dvorský ◽

Šedý ◽

Msallamová ◽

Levorová ◽

...

Keyword(s):

Hot Extrusion ◽

Visual Observation ◽

Structure Characterization ◽

Zinc Alloy ◽

Biodegradable Materials ◽

Medical Implants ◽

Conventional Casting ◽

Tension And Compression

Biodegradable materials are of interest for temporary medical implants like stents for restoring damaged blood vessels, plates, screws, nails for fixing fractured bones. In the present paper new biodegradable Zn–2Mg alloy prepared by conventional casting and hot extrusion was tested in in vitro and in vivo conditions. Structure characterization and mechanical properties in tension and compression have been evaluated. For in vivo tests, hemispherical implants were placed into a rat cranium. Visual observation of the living animals, an inspection of implant location and computed tomography CT imaging 12 weeks after implantation were performed. Extracted implants were studied using scanning electron microscopy (SEM) on perpendicular cuts through corrosion products. The behaviour of zinc alloy both in in vitro and in vivo conditions was compared with commercially used Mg-based alloy (Mg–4Y–3RE) prepared by conventional casting and hot extrusion. Both compressive and tensile yield strengths of Zn and Mg-based alloys were similar; however, the brittleness of Mg–4Y–3RE was lower. Zn and Mg-based implants have no adverse effects on the behaviour or physical condition of rats. Moreover, gas bubbles and the inflammatory reaction of the living tissue were not detected after the 12-week period.

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Chitosan-miRNA functionalized microporous titanium oxide surfaces via a layer-by-layer approach with a sustained release profile for enhanced osteogenic activity

Journal of Nanobiotechnology ◽

10.1186/s12951-020-00674-7 ◽

2020 ◽

Vol 18 (1) ◽

Author(s):

Kaimin Wu ◽

Mengyuan Liu ◽

Nan Li ◽

Li Zhang ◽

Fanhui Meng ◽

...

Keyword(s):

Sustained Release ◽

Osteogenic Differentiation ◽

Sodium Hyaluronate ◽

Release Profile ◽

Titanium Implants ◽

Layer By Layer ◽

Matrix Mineralization ◽

In Vitro Transfection

Abstract Background The biofunctionalization of titanium implants for high osteogenic ability is a promising approach for the development of advanced implants to promote osseointegration, especially in compromised bone conditions. In this study, polyelectrolyte multilayers (PEMs) were fabricated using the layer-by-layer approach with a chitosan-miRNA (CS-miRNA) complex and sodium hyaluronate (HA) as the positively and negatively charged polyelectrolytes on microarc-oxidized (MAO) Ti surfaces via silane-glutaraldehyde coupling. Methods Dynamic contact angle and scanning electron microscopy measurements were conducted to monitor the layer accumulation. RiboGreen was used to quantify the miRNA loading and release profile in phosphate-buffered saline. The in vitro transfection efficiency and the cytotoxicity were investigated after seeding mesenchymal stem cells (MSCs) on the CS-antimiR-138/HA PEM-functionalized microporous Ti surface. The in vitro osteogenic differentiation of the MSCs and the in vivo osseointegration were also evaluated. Results The surface wettability alternately changed during the formation of PEMs. The CS-miRNA nanoparticles were distributed evenly across the MAO surface. The miRNA loading increased with increasing bilayer number. More importantly, a sustained miRNA release was obtained over a timeframe of approximately 2 weeks. In vitro transfection revealed that the CS-antimiR-138 nanoparticles were taken up efficiently by the cells and caused significant knockdown of miR-138 without showing significant cytotoxicity. The CS-antimiR-138/HA PEM surface enhanced the osteogenic differentiation of MSCs in terms of enhanced alkaline phosphatase, collagen production and extracellular matrix mineralization. Substantially enhanced in vivo osseointegration was observed in the rat model. Conclusions The findings demonstrated that the novel CS-antimiR-138/HA PEM-functionalized microporous Ti implant exhibited sustained release of CS-antimiR-138, and notably enhanced the in vitro osteogenic differentiation of MSCs and in vivo osseointegration. This novel miRNA-functionalized Ti implant may be used in the clinical setting to allow for more effective and robust osseointegration.

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Development of an In Vitro Porcine Aorta Model to Study the Stability of Stent Grafts in Motor Vehicle Accidents

Journal of Biomechanical Engineering ◽

10.1115/1.2948398 ◽

2009 ◽

Vol 131 (4) ◽

Cited By ~ 4

Author(s):

Kurosh Darvish ◽

Mehdi Shafieian ◽

Vasily Romanov ◽

Vittorio Rotella ◽

Michael D. Salvatore ◽

...

Keyword(s):

Stent Graft ◽

Motor Vehicle ◽

Motor Vehicle Accidents ◽

Aortic Aneurysms ◽

Endovascular Stent ◽

Stent Grafts ◽

Vehicle Accidents ◽

Impact System ◽

The Stability

Endovascular stent grafts for the treatment of thoracic aortic aneurysms have become increasingly utilized and yet their locational stability in moderate chest trauma is unknown. A high speed impact system was developed to study the stability of aortic endovascular stent grafts in vitro. A straight segment of porcine descending aorta with stent graft was constrained in a custom-made transparent urethane casing. The specimen was tested in a novel impact system at an anterior inclination of 45deg and an average deceleration of 55G, which represented a frontal automobile crash. Due to the shock of the impact, which was shown to be below the threshold of aortic injury, the stent graft moved 0.6mm longitudinally. This result was repeatable. The presented experimental model may be helpful in developing future grafts to withstand moderate shocks experienced in motor vehicle accidents or other dynamic loadings of the chest.

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EFFECT OF FORMALDEHYDE TREATMENT OF SOYBEAN MEAL ON RATES OF PROTEIN DEGRADATION AND MICROBIAL PROTEIN CONCENTRATION IN THE BOVINE RUMEN

Canadian Journal of Animal Science ◽

10.4141/cjas83-021 ◽

1983 ◽

Vol 63 (1) ◽

pp. 181-190 ◽

Cited By ~ 12

Author(s):

S. MAHADEVAN ◽

R. M. TEATHER ◽

J. D. ERFLE ◽

F. D. SAUER

Keyword(s):

Soybean Meal ◽

Latin Square ◽

Experimental Period ◽

Ammonia Concentration ◽

Bovine Rumen ◽

Rumen Degradation ◽

Formaldehyde Treatment ◽

Highly Correlated

Four rumen-fistulated cows were fed concentrate:corn silage (40: 60) diets in a 4 × 4 latin square design experiment. The diets differed in the soybean meal or soybean meal treated with 0.1, 0.3 or 0.6% (wt/wt) formaldehyde. Rumen contents were collected hourly from 0900 h to 1600 h with an additional sample at half an hour after the 1100 h feeding on 3 days in the second week of each 2-wk experimental period. The maximum ammonia concentration in rumen contents decreased with increasing levels of formaldehyde used to treat the soybean meal. From 1130 to 1200 h the rates of ammonia appearance in the rumen contents were different (P < 0.05) for all four diets. Treatment of soybean meal with between 0.1 and 0.3% (wt/wt) formaldehyde reduced its in vitro degradation by rumen protease by about 50% compared with the untreated control. The rates of in vivo ammonia appearance and in vitro proteolysis were highly correlated (r = 0.966, P < 0.01) between 1130 h and 1200 h. These rates of rumen ammonia appearance reflected the in vivo rate of proteolysis. Both bacterial and protozoal protein content decreased significantly at the higher levels of formaldehyde treatment. There was a negative correlation (r = − 0.63, P < 0.01) between protozoal and bacterial protein. Key words: Formaldehyde, soybean meal, bovine, rumen, degradation, protease

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In Vitro and In Vivo Bioactivity of Tricalcium Phosphate and Fluoroapatite Nanoparticles for Medical Implants

Science of Advanced Materials ◽

10.1166/sam.2020.3563 ◽

2020 ◽

Vol 12 (1) ◽

pp. 101-109

Author(s):

H. Algarni ◽

Ibrahim Alshahrani ◽

Essam H. Ibrahim ◽

Refaat A. Eid ◽

Mona Kilany ◽

...

Keyword(s):

Antimicrobial Activity ◽

Antimicrobial Activities ◽

Potential Candidate ◽

Medical Implants ◽

Splenic Cells ◽

Acute Cytotoxicity ◽

Good Potential ◽

Sbf Solution

A novel 40P2O5–20Na2O–10Ca(OH)2–20CaCl2–6.0ZnO–2.0BaF2–2.0TiO2 (BGBaFTi) bioglasses is prepared. The reaction of the glasses in SBF solution is characterized by XRD and SEM indicated that the carbonate hydroxyapatite has formed rapidly on the glasses. BGBaFTi bioglasses was tested for its antimicrobial activity, anti-proliferative/cytotoxicity against normal and activated splenic cells in vitro and in vivo. This results showed that BGBaFTi has antimicrobial activities against Gram negative and positive bacteria as well as fungi. We found that the antimicrobial activity of nanoparticles of BGBaFTI is high than the normal powder of it. Moreover BGBaFTi (powder and nanoparticle) with cytotoxic effect on normal splenic cells was investigated. The products of activated splenic cells did not cause any changes in the structure of BGBaFTi. It did not cause any acute cytotoxicity or lysis to RBCs which was not affected by lytic products of immune cells. The bioactivity and biocompatibility of the present glasses use it a good potential candidate in the field of tissue engineering.

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