Papers by Keyword: Cytocompatibility

Abstract: This work aims to review current trends in research within the field of iron-based scaffolds for orthopaedic applications. Current research is trapped in a ‘see-saw’ type problem where an increase in corrosion rate of the base metal is required to accelerate the degradation process making the resorption time compatible with the healing time. This is done via several methods including porosity control, cathodic element addition and/or patterning and alloying. In turn, this increase in corrosion rate causes the local concentration of metallic ions to increase beyond the toxicity limit for osteoblast type cells, thus negatively effecting cytocompatibility. This is most pronounced when considering the orthopaedic environment, in which static conditions provide for increased local ion concentrations, resulting in local toxicity. However, research from the medical field of Thalassemia may help solve this dilemma by providing chelation medicine for patients undergoing implantation of resorbable orthopaedic scaffolds, throughout the resorption period. Excretion of iron would then be provided mainly through bowel movement and urination.

Abstract: During the last decades, biomaterials have been deeply studied to perform and improve coatings for biomedical devices. Metallic materials, especially in the orthopedic field, represent the most common material used for different type of devices thanks to their good mechanical properties. Nevertheless, low/medium resistance to corrosion and low osteointegration ability characterizes these materials. To overcome these problems, the use of biocoatings on metals substrate is largely diffused. In fact, biocoatings have a key role to confer biocompatibility properties, to inhibit corrosion and thus improve the lifetime of implanted devices. In this work, the attention was focused on Hydroxyapatite-Chitosan (HA/CS) and Hydroxyapatite-Polyvinylacetate (HA/PVAc) composites, that have been studied as biocoatings for 304 SS based devices. Hydroxyapatite was selected for its osteoconductivity thanks to its chemical structure similar to bones. Furthermore, Chitosan and Polyvinylacetate are largely used yet in medical field (e.g. antibacterial agent or drug deliver) and in this work were used to create a synergic interaction with hydroxyapatite to increase the strength and bioactivity of coating. Biocotings were obtained by galvanic deposition process that does not require an external power supply. It is a spontaneous electrochemical deposition in which materials with different standard electrochemical potential were short-circuited and immersed in an electrolytic solution. Electrons supply for the cathodic reaction in the noblest material comes from oxidation of the less noble material. SEM, EDS, XRD and RAMAN were performed for chemical-physics characterization of biocoatings. Polarization and impedance measurements have been carried out to evaluate corrosion behavior. Besides, in-vitro cytotoxicity assays have been done for the biological features.

Abstract: In this study, we investigated the cytocompatibility of ceramic nanoparticles on different types of cells. All ceramics nanoparticles investigated in this study except Copper oxide (CuO) exhibited good cytocompatibility and cell viability (90% or more) even at 20 ppm concentration. In contrast, CuO nanoparticles caused cell inflammation, and their effect depended on their particle size. Confocal fluorescence microscopy measurements indicated that some particles had penetrated into the cells. These results indicate that except CuO nanoparticles, all other ceramic nanoparticles reported herein exhibited excellent cytocompatibility even for lung epithelial cells.

Abstract: We modified the surface of organically modified montmorillonite (OMMT) with the carboxyl group using the silane coupling reaction and assessed its characteristics and cytocompatibility. Scanning electron microscope observations show that while the size and morphology of the obtained OMMT (OMMT-COOH) was unchanged, the surface of OMMT-COOH was coarser than that of OMMT. Fourier transform infrared spectra showed characteristic strong peaks at 1210 and 1630 cm⁻¹, corresponding to the peaks of the carboxyl group. X-ray diffraction analysis showed that the diffraction peak of OMMT-COOH corresponding to the (001) reflection was located at higher a 2θ value than that of OMMT. Results of the proliferation ratio and cell viability measurements indicated that the OMMT-COOH cytocompatibility is higher than that of OMMT. Based on these results, we conclude that cytocompatibility of montmorillonite would be improved by tuning the properties of the surface.

Abstract: In order to evaluate the cytocompatibility and hemolytic properties of n-HA/PEEK biocomposites the nanohydroxyapatite/polyetheretherketone (n-HA/PEEK) biocomposites were successfully prepared. The mechanical properties of the biocomposites were proximal to human bone, at the same time, they had the optimal value with the HA volume content of 5%. The PEEK and n-HA/PEEK biocomposites with different HA content extraction medium was prepared with fresh medium. Simple DMEM culture solution was taken as negative control group. The pure PEEK and 5vol.%, 15vol.%, 30vol.% n-HA/PEEK biocomposites were the testing group. The relative proliferation rate of L929 cells was determined on the 1^st, 2^nd, 3^rd and 6^th days with CCK-8 assay. The cytotoxicity of n-HA/PEEK biocomposites were evaluated according to ISO 10993-5: 2009. The L929 cells morphology and growth on the 1^st, 2^nd, 3^rd and 6^th days were determined under inverted microscope. The hemolysis test in vitro of n-HA/PEEK biocomposites were evaluated through measuring erythrocyte lysis and ferro-hemoglobin freeing degree with indirect contact method basing on ISO 10993-4:2009. The experimental results showed that the growth and morphology of cells in pure PEEK and n-HA/PEEK biocomposites extraction medium had no difference from negative control group. Cytotoxicity test showed that PEEK and n-HA/PEEK biocomposites did not have obvious toxicity on L929 cells, and the cytotoxicity of these extracts was in grade 0-1. Hemolysis test suggested that PEEK and n-HA/PEEK biocomposites did not have obvious hemolysis reaction, and the hemolysis rate of PEEK and n-HA/PEEK biocomposites were 2.37%, 1.71%, 1.05% and 1.32% respectively, which are less than the national standard (5%). It may be concluded that the n-HA/PEEK biocomposites did not have obvious cytotoxicity and hemolysis reaction, which demonstrated that n-HA/PEEK biocomposites had good cytocompatibility.

Abstract: The objective was to manufacture a nanostructured lipid carrier (NLC) for Coenzyme Q10, and to investigate its prolonged release and cytocompatibility of CoQ10-NLC incubated with HaCaT cells. CoQ10-NLC was prepared by hot high-pressure homogenization technique. The characterization of the CoQ10-NLC was determined by size analysis, polydispersity index (PDI), zeta potential assay, in vitro release and cytocompatibility. To analyze the cytocompatibility of CoQ10-NLC, cell viability was investigated by MTT measurement. Morphology of cells was evaluated by HE staining. Cells were exposed to CoQ10-NLC and nuclear morphology were determined using Hoechst 33342 staining. Time-lapse imaging was used to illustrate the dynamics of cell movements. Release investigation exhibited a prolonged release of CoQ10-NLC. MTT measurement, HE and Hoechst 33342 staining corroborated that CoQ10-NLC possessed good cytocompatibility on HaCaT cells. Observation with time-lapse images further confirmed that CoQ10-NLC showed good cytocompatibility. The results demonstrated that CoQ10-NLC with prolonged release had good cytocompatibility.

Abstract: Poly (L-lactide-co-D/L-lactide)-based fiber meshes resembling structural features of the native extracellular matrix have been prepared by electrospinning. Subsequent coating of the electrospun fibers with an ultrathin plasma polymerized allylamine (PPAAm) layer changed the hydrophobic nature of the polylactide surface into a hydrophilic polymer network and provided positively charged amino groups on the fiber surface able to interact with negatively charged pericellular matrix components. Cell experiments in vitro using different types of human epithelial cells (gingiva, uroepithel) revealed that the PPAAm-activated surfaces promoted the occupancy of the meshes by cells accompanied by improved initial cell spreading. An in vivo study in a rat intramuscular implantation model demonstrated that the local inflammatory tissue response did not differ between PPAAm-coated and untreated polylactide meshes.

Abstract: Magnesium (Mg)-based alloys have attracted great interest as metallic biomaterials for orthopedic applications due to their biocompatibility, biodegradability, and mechanical properties that resemble those of cortical bone. However, the potential toxicity of alloying elements in commercially available Mg alloys makes it critical to engineer and screen new alloys specifically for biomedical applications. The objective of this study was to evaluate and compare the in vitrodegradation and cytocompatibility of two distinct Mg - Zinc (Zn) - Calcium (Ca) alloys (Mg-4%Zn-1%Ca and Mg-9%Zn-1%Ca, wt. %; abbreviated as ZCa41 and ZCa91, respectively) using a bonemarrow derived mesenchymal stem cell (BMSC) model. Both Zn and Ca play critical roles in boneformation and growth, and have been shown to increase mechanical and corrosion properties of Mgalloys. BMSCs provide vertebrates the continuous supply of osteoblasts needed for bone remodelingand repair, and thus were selected to determine the effect of increasing Zn content on cell behavior.Surface microstructure and composition of the alloys were characterized before and after BMSC culture using field emission scanning electron microscopy (FESEM) and energy dispersive X-rayspectroscopy (EDS). Thermanox® treated glass and plasma treated tissue culture polystyrene were used as a control and reference, respectively. Results indicated that the ZCa91 alloy improved BMSC adhesion as compared with ZCa41 alloy. The formation of high-aspect ratio needle-likefeatures on the surface of ZCa41 alloy after its degradation in cell culture media was speculated tocontribute to the lower cell adhesion. This study provided an early indication on cytocompatibility of Mg-Zn-Ca alloys for biomedical applications.

Abstract: A novel biomaterial poly (butylene carbonate) (PBC) was used to fabricate aligned nanofibresby electrospinning with a high-speed transfer roller as the receiving device. The morphology of the fibers was evaluated by scanning electron microscopy (SEM). To expand the application of the biomaterial, cold plasma treatment and induced grafting technology were applied to improve its hydrophilicity and biocompatibility. The properties of the fibers, pretreated withhelium and following grafting with gelatin,were evaluated with X-ray photoelectron spectroscopy. The cytotoxicity of the materials to Schwann cells (RSC96) was investigated. Results indicated that aligned nanofibers can be received at high rotation speed.After plasma pretreatment, the activity of the surface was improved significantly and the grafting reaction was successful. SEM observations showed that cells can grow on the fibersurface along the direction of fiberorientation after seeding with RSC96 for 3 and 5 days. Modification of the nanofibersurface with gelatin significantly increased RSC96 attachment and proliferation.

Abstract: The glycerides of castor oil (GCO) were copolymerized with isophorone diisocyanate (IPDI) to generate glyceride-based polyurethane (GCPU), meanwile blending with hydroxyapatite (HA) powder to fabricate porous composite scaffolds. The effect of HA content on mechanical properties of the resulting polymer scaffolds and the in vitro cell response of HA/GCPU scaffolds were investigated, by use of mechanical testing, FTIR, SEM and MTT assay. The results showed that the compressive strength increased with HA content, and the HA/GCPU scaffold with 40 wt% HA reached about 4.6 MPa, much higher than the scaffold without HA (only 605 kPa). The SEM observation, live-dead staining assay and MTT assay demonstrated the excellent biological properties of HA/GCPU scaffolds, which support cell adhesion and proliferation. This novel class of HA/GCPU porous scaffolds have prospect and advantage for bone repair and regeneration.