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   To broaden the knowledge of cytotoxicity of natural rubber latex (NRL) nanoparticles we for the first time examined the latex biocompatibility in vitro against mouse calvaria preosteoblast cells (MC3T3-E1) and human alveolar basal epithelial (A549) cells. For NRL nanoparticles, the half maximal inhibitory concentration (IC50) value for MC3T3-E1 cells is one order of magnitude higher in toxicity as compared to that of A549 cells (3.99 mg/mL for MC3T3-E1 and 0.33 mg/mL for A549 cells). Owing to fractionation of NRL nanoparticles by ultra-centrifuge, the effect of the non-rubber constituents on the cytotoxicity was clarified. The suppression on the proliferation for A549 cells incubated with NRL nanoparticles was demonstrated by the cell cycle distribution. The in vitro study on osteogenic differentiation and expressions of proteins and characteristic genes of MC3T3-E1 cells demonstrated the promising results of the NRL nanoparticles for application in bone tissue engineering.

e-Journal of Soft Materials
2017

   To broaden the knowledge of cytotoxicity of natural rubber latex (NRL) nanoparticles we for the first time examined the latex biocompatibility in vitro against a panel of cancer cells (A549, A2780, and MDA-MB-231). Owing to fractionation of NRL nanoparticles by ultra-centrifuge, the effect of the non-rubber constituents (intermediate of 5.8 wt.% and sediment of 0.2 wt.%) on the cytotoxicity was clarified. For intermediate constituent, the half maximal inhibitory concentration (IC50) values at 24 h was 1.05 mg/mL for A549 cells, which was one order of magnitude higher in toxicity as compared to that for A2780 (0.24 mg/mL) and MDA-MB-231 (0.36 mg/mL) cells. In addition, profound studies including cell cycle arrest abilities and apoptosis induction profiles against cancer cells were discussed in detail. It was found that the constituents exhibit some significant effect on the cell cycle arrest and trigger apoptosis for A2780 cells. This effective apoptosis induction profiles was more prominent in MDA-MB-231 cells incubated with NRL nanoparticles and sediment loading conditions. The percentage of apoptotic cells was ca. 6–8% of the total cells.

Materials Today Chemistry
2017, 5, 63-71

   Natural rubber latex (NRL) is mainly used around traditional industrial products, but currently their target application is continuously expanding into tissue engineering. To broaden our knowledge of application in tissue engineering of NRL, we have focused on the surface modification of NRL nanoparticles through the biomineralization of hydroxyapatite (HA) using simulated body fluid in order to create a better cytocompatibility with controlled cell adhesion and mineralization properties in osteogenic culture to determine the effect on bone outcomes. Using MC3T3-E1 mouse osteoblastic-like cells incubated with NRL nanoparticles coated with HA layer, we have examined the osteogenic differentiation and expressions of multiple proteins and characteristic genes of mature osteoblast. We have successfully prepared the biocomposites composed of NRL and bone tissue.

Nanocomposites
DOI: 10.1080/20550324.2017.1352111

   The interpretation of the local microenvironment of extracellular matrix for malignant tumor cells is in intimate relation with metastatic spread of cancer cells involving the associated issues of cellular proliferation and drug responsiveness. This study was aimed to assess the combination of both surface topographies (fiber alignments) and different stiffness of the polymeric substrates (PLLA and PCL) and collagen substrates (coat and gel) to elucidate the effect of the cellular morphology on cellular proliferation and drug sensitivities of two different types of breast cancer cells (MDA-MB-231 and MCF-7). The morphological spreading parameter of (Nuclear/Cytoplasm) induced by the anthropogenic substrates has correlated intimately with the cellular proliferation and the drug sensitivity (IC50) of cancer cells. This study demonstrated the promising results of the parameter for the evaluation of cancer cell malignancy.

Journal of Functional Biomaterials
2017, 8, 18


   The complexation of allophane nanoparticles with cisplatin, cis-dichlorodiammineplatinum (II) (CDDP) to deliver platinum prodrug into cancer cells was investigated. Using human lung carcinoma (A549) cells, profound studies including cellular uptake (endocytosis) analysis of allophane nanoparticle, cell cycle arrest abilities and apoptosis induction profiles were discussed in detail. As well as the features against A549 cells to emerge a promising strategy to enhance their anti-cancer activity and to mitigate side-effects were discussed.

Applied Clay Science
DOI:10.1016/j.clay.2017.04.017(2017)


   Progresses of microenvironment-mediated tumor progression in artificial extracellular matrix explore the design criteria to understand the cancer progression mechanism and metastatic potential. This study was aimed to assess the combination of both surface topographies (fiber alignments) and different stiffness of the polymeric substrates (PLLA and PCL) to evaluate the effect on the cellular morphologies, proliferation, motility and gene expression regarding epithelial to mesenchymal transition (EMT) of two different types of breast cancer cells (MDA-MB-231 and MCF-7). The cellular morphologies (roundness and nuclear elongation factor), E-cadherin and vimentin expression, and cellular motility in terms of cellular migration speed, persistent time and diffusivity were discussed comprehensively. We have demonstrated that the microenvironment of cell culture substrates influences cancer progression and metastatic potential.

Journal of Materials Chemistry B
DOI:10.1039/C7TB00207F(2017)

   Clay minerals are mainly used around traditional cosmetics and industrial products, but currently their target application is continuously expanding into pharmaceutical industry and tissue engineering. To broaden the knowledge of in vitro cytotoxicity of allophane nanoparticles against human cancer cells, the cytotoxicity of both natural and synthetic allophane nanoparticles for cultured human alveolar basal epithelial (A549) cells was examined. For both natural and synthetic allophones, the A549 cell viability was maintained at > 70% for concentration up to 3160 mg/mL, implying higher biocompatibility of allophane nanoparticles as compared with that of hectorite nanoparticles. The cell adhesion kinetics coupled with cytotoxic characteristics against A549 cells was analyzed using quartz crystal microbalance (QCM) technique to distinguish the dynamic cell adhesion signatures.

Applied Clay Science
DOI:10.1016/j.clay.2016.10.037(2016)

     Poly-L-lactide (PLLA)/natural hydroxyapatite (n-HA) composite scaffolds with different morphology and porosity were prepared using thermally induced phase separation (TIPS) technique. The morphological features of the scaffolds were observed by field emission scanning electron microscope (FE-SEM). The solvent concentration had much effect on the porosity and pore morphology. The double-stranded deoxyribonucleic acid (ds-DNA) adsorption behavior was investigating with the aim of their applications in gene therapy. The propensity of the scaffolds and n-HA particles to adsorb ds-DNA was assessed by batch experiments at pH 4. The aggregated size of the ds-DNA molecules and agglomeration after adsorption were characterized by dynamic light scattering (DLS) and Fourier transform infrared (FTIR) spectroscopic imaging.
The adsorption data were fitted into the Freundlich equation and the adsorption parameters were assessed. Although the adsorption capacity of the scaffolds was lower as compared to n-HA particles, it was sufficient for ds-DNA adsorption. The in vitro cell culture test was conducted on the scaffolds with human mesenchymal stem cells (hMSCs). The cells on PLLA/n-HA/ds-DNA scaffold showed more significant increases than neat PLLA and PLLA/n-HA scaffolds. 

Polymer

2015, 56, 73-81

   Clay mineral surfaces have been important for the prebiotic organization and protection of nucleic acids. The morphological observation to provide insight into the adsorption structure and characteristics of single-stranded DNA (ss-DNA) by natural allophane particles was presented. The molecular orbital (MO) computer simulation has been used to probe the interaction of ss-DNA and/or adenosine 5’-monophosphate and allophane with active sites. Our simulations predicted the strand undergoes some extent of the elongation, which induces the alteration of the conformation of the phosphate backbone, base-base distance and excluded volume correlation among bases. This work demonstrates the ss-DNA adsorption by the allophane particles with novel insights into the morphological features and detailed molecular level information. The overall results support a general adsorption mechanism for the ss-DNA/allophane complexation

Applied Clay Science
2014, 101, 591-597


   To understand the enzymatic degradation behavior of crosslinked polylactide (PLA), the preparation and enzymatic degradation of both thermoplastic (linear) and crosslinked PLAs having pore structure with different dimension were carried out. The porous structures of the linear PLA samples were of micro and nanoporous range prepared by batch foaming at supercritical CO2 and compared with the porous structures of crosslinked PLA (Lait-X) created by salt leaching method. The surface and cross-sectional morphologies of the porous structures were investigated by using scanning electron microscopy. The morphological analysis of Lait-X porous showed a rapid loss of physical features with 120 h of exposure to the proteinase-K enzymatic degradation at 37 °C. Due to higher affinity for water led to enhanced enzymatic activity as compared to the linear PLA porous structures in the micro and nanoporous range.

International Journal of Molecular Science
2014, 15, 9793-9808

   Allophane nanoparticles were synthesized through a hydrothermal treatment of precursor with Si/Al molar ratio of 0.75 at 100°C for 48 h and characterized by using field emission scanning electron microscopy, pore-size distribution based on the Cranston-Inkley method, 29Si and 27Al magic angle spinning nuclear magnetic resonance, X-ray diffractometry, and energy dispersive X-ray spectroscopy. It is demonstrated that the synthetic allophane nanoparticle leads to a novel allophane-Pt nanocomposite with the metal particle size of ~ 2 nm and narrow size distribution. The synthetic allophane particles promote the reduction of K2PtCl4 to Pt0 and act as a support substratum. The molecular orbital computer simulation was performed to provide insight into the structure and stability of Pt nanoparticles during complexation by the functional (OH)Al(OH2) groups on the wall perforations of the synthetic allophane.

Applied Clay Science
2014, 95, 191-196