Publication: ACS Appl. Energy Mater. 2021, XXXX, XXX, XXX-XXX, Publication Date: March 22, 2021.

Abstract: Cesium formadinium methylammonium triple-cation (CsFAMA) lead mixed-halide perovskites have been reported to promote unique photovoltaic properties with high efficiency and minimal hysteresis effects. Perovskite film quality is a vital parameter for improving the performance of perovskite solar cells (PSCs). Here, we report the growth of CsFAMA perovskites with microscale grains passivation grain boundaries by mixing HC(NH₂)₂I (FAI) and CH₃NH₃Br (MABr) in isopropanol (IPA) as a post-treatment step to cause controlled Ostwald ripening, leading to secondary grain growth. Compared to the conventional preparation of perovskite films with a free organic halide antisolvent, this mixed-cation mixed-halide post-treatment created higher quality perovskite films in terms of morphology, electronic properties, energy level alignment, and carrier recombination, with the band gap adjusted at the optimal concentration. Treatment with the single cation and single halide presented by FAI and/or MABr in IPA treatment was also investigated, and the results showed that multiple band gap perovskite structures were obtained, which could be beneficial for band gap engineering. This method of perovskite preparation was tested in an inverted planar configuration with a hole transport layer (HTL) based on sulfonated poly(thiophene-3-[2-(2-methoxy-ethoxy)ethoxy]-2,5-diyl) (SP3MEET). The efficiency of the PSCs was dramatically boosted from 13.80% with the organic halide-free antisolvent to 17.62% when the mixed-cation mixed-halide approach was used. In addition, the PSCs treated with the mixed-cation mixed-halide solution exhibited excellent reproducibility, with a high fill factor and eliminated hysteresis. The CsFAMA photovoltaic device based on the single organic cation and single halide treatment approach showed power conversion efficiency of 15.82 and 15.90% for the FAI and MABr-treated films, respectively. Characterization of the S-P3MEET as HTLs found that good optoelectronic and morphological properties lead to improve the performance of the inverted PSC. However, with further research to align the energy levels at the S-P3MEET/perovskite interface, greater improvements in the PSCs are expected.

The post Surface Passivation of Triple-Cation Perovskite via Organic Halide-Saturated Antisolvent for Inverted Planar Solar Cells appeared first on Center for Integrative Nanotechnology Sciences.

Publication: J Appl Toxicol. 2021 Jan 8. doi: 10.1002/jat.4136. Epub ahead of print. PMID: 33417269.

Abstract: The use of synthetic materials for biomedical applications is ever expanding. One of the major requirements for these materials is biocompatibility, which includes prevention of immune system responses. Due to the inherent complexity of their structural composition, the polyurethane (PU) family of polymers is being used in a variety of medical applications, from soft and hard tissue scaffolds to intricate coatings on implantable devices. Herein, we investigated whether two polymer materials, D3 and D7, induced an immune response, measured by their effects on a dendritic cell (DC) line, JAWS II. Using a lactate dehydrogenase cytotoxicity assay and Annexin V/PI staining, we found that the PU materials did not induce cytotoxicity in DC cells. Using confocal microscopy, we also showed that the materials did not induce activation or maturation, as compared to positive controls. This was confirmed by looking at various markers, CD80, CD86, MHC class I, and MHC class II, via flow cytometry. Overall, the results indicated that the investigated PU films are biocompatible in terms of immunotoxicology and immunogenicity and show great promise for use in regenerative medicine.

The post Dendritic cell biocompatibility of ether-based urethane films appeared first on Center for Integrative Nanotechnology Sciences.

Publication: Environ Sci Pollut Res Int. 2020 Jun 20. doi: 10.1007/s11356-020-09400-0. Epub ahead of print. PMID: 32564317

Abstract: Nanocomposites containing mixed metal oxides show excellent phosphate removal results and are better compared to individual metal oxides. In this research, cerium/manganese oxide nanocomposites, embedded on the surface of modified cellulose pine wood shaving, were synthesized by a simple technique that is both eco-friendly and economically feasible. No toxic or petroleum chemicals were employed during preparation. Scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), surface area analysis, and attenuated total reflectance Fourier-transform infrared (ATR-FTIR) spectroscopy were performed to study the shape and size of nanocomposites as well as composition of elements present on the surface of the nanocomposites. Adsorption isotherm (Langmuir, Freundlich, Temkin, and Dubinin-Radushkevich) and kinetic studies (pseudo first and second-order, Elovich and Weber-Morris) were carried out to determine the adsorption mechanism for phosphate removal from contaminated water. The maximum adsorption capacity of nanocomposites was found to be 204.09 mg/g, 174.42 mg/g, and 249.33 mg/g for 100 mg, 300 mg, and 500 mg, respectively. The results indicate that the nanocomposites were able to decrease the phosphorus concentration from 10 to 0.01 ppm, below the threshold limit required by EPA guidelines in the USA. We also demonstrated that the media could be regenerated and reused five times without loss of performance.

The post Phosphate removal from wastewater using novel renewable resource-based, cerium/manganese oxide-based nanocomposites appeared first on Center for Integrative Nanotechnology Sciences.

Publication: J Environ Manage. 2020 Jul 12;272:111048. doi: 10.1016/j.jenvman.2020.111048. Epub ahead of print. PMID: 32677621.

Abstract: Phosphate is one of the most costly and complex environmental pollutants that leads to eutrophication, which decreases water quality and access to clean water. Among different adsorbents, biochar is one of the promising adsorbents for phosphate removal as well as heavy metal removal from an aqueous solution. In this study, biochar was impregnated with nano zinc oxide in the presence of glycine betaine. The Zinc Oxide Betaine-Modified Biochar Nanocomposites (ZnOBBNC) proved to be an excellent adsorbent for the removal of phosphate, exhibiting a maximum adsorption capacity of phosphate (265.5 mg. g^-1) and fast adsorption kinetics (~100% removal at 15 min at 10 mg. L^-1 phosphate and 3 g. L^-1 nanocomposite dosage) in phosphate solution. The synthesis of these benign ZnOBBNC involves a process that is eco-friendly and economically feasible. From material characterization, we found that the ZnOBBNC has ~20-30 nm particle size, high surface area (100.01 m². g^-1), microporous (25.79 Ă…) structures, and 7.64% zinc content. The influence of pH (2-10), coexisting anions (Cl^–, CO₃^2-, NO₃^– and SO₄^3-), initial phosphate concentration (10-500 mg. L^-1), and ZnOBBNC dosage (0.5-5 g. L^-1) were investigated in batch experiments. From the adsorption isotherms data, the adsorption of phosphate using ZnOBBNC followed Langmuir isotherm (R² = 0.9616), confirming the mono-layered adsorption mechanism. The kinetic studies showed that the phosphate adsorption using ZnOBBNC followed the pseudo-second-order model (R² = 1.0000), confirming the chemisorption adsorption mechanism with inner-sphere complexion. Our results demonstrated ZnOBBNC as a suitable, competitive candidate for phosphate removal from both mock lab-prepared and real field-collected wastewater samples when compared to commercial nanocomposites.

The post Benign zinc oxide betaine-modified biochar nanocomposites for phosphate removal from aqueous solutions appeared first on Center for Integrative Nanotechnology Sciences.

Publication: PLoS One. 2020;15(5):e0232670. Published 2020 May 18. doi:10.1371/journal.pone.0232670

Abstract: Complex skin wounds have always been a significant health and economic problem worldwide due to their elusive and sometimes poor or non-healing conditions. If not well-treated,
such wounds may lead to amputation, infections, cancer, or even death. Thus, there is a need to efficiently generate multifunctional skin grafts that address a wide range of skin conditions, including non-healing wounds, and enable the regeneration of new skin tissue. Here, we propose studying pristine graphene and two of its oxygen-functionalized derivatives—high and low-oxygen graphene films—as potential substrates for skin cell proliferation and differentiation. Using BJ cells (human foreskin-derived fibroblasts) to represent basic skin cells, we show that the changes in surface properties of pristine graphene due to oxygen functionalization do not seem to statistically impact the normal proliferation and maturation of skin cells. Our results indicate that the pristine and oxidized graphenes presented relatively low cytotoxicity to BJ fibroblasts and, in fact, support their growth and bioactivity. Therefore, these graphene films could potentially be integrated into more complex skin regenerative systems to support skin regeneration. Because graphene’s surface can be relatively easily functionalized with various chemical groups, this finding presents a major opportunity for the development of various composite materials that can act as active components in regenerative applications such as skin regeneration.

The post Graphene-based 2D constructs for enhanced fibroblast support appeared first on Center for Integrative Nanotechnology Sciences.

Publication:  Int J Nanomedicine. 2020;15:2501-2513. Published 2020 Apr 15. doi:10.2147/IJN.S245801

Abstract:

Purpose: The extracellular matrix (ECM) labyrinthine network secreted by mesenchymal stem cells (MSCs) provides a microenvironment that enhances cell adherence, proliferation, viability, and differentiation. The potential of graphene-based nanomaterials to mimic a tissue-specific ECM has been recognized in designing bone tissue engineering scaffolds. In this study, we investigated the expression of specific ECM proteins when human fat-derived adult MSCs adhered and underwent osteogenic differentiation in the presence of functionalized graphene nanoparticles.

Methods: Graphene nanoparticles with 6-10% oxygen content were prepared and characterized by XPS, FTIR, AFM and Raman spectroscopy. Calcein-am and crystal violet staining were performed to evaluate viability and proliferation of human fat-derived MSCs on graphene nanoparticles. Alizarin red staining and quantitation were used to determine the effect of graphene nanoparticles on osteogenic differentiation. Finally, immunofluorescence assays were used to investigate the expression of ECM proteins during cell adhesion and osteogenic differentiation.

Results: Our data show that in the presence of graphene, MSCs express specific integrin heterodimers and exhibit a distinct pattern of the corresponding bone-specific ECM proteins, primarily fibronectin, collagen I and vitronectin. Furthermore, MSCs undergo osteogenic differentiation spontaneously without any chemical induction, suggesting that the physicochemical properties of graphene nanoparticles might trigger the expression of bone-specific ECM.

Conclusion: Understanding the cell-graphene interactions resulting in an osteogenic niche for MSCs will significantly improve the application of graphene nanoparticles in bone repair and regeneration.

The post Functionalized Graphene Nanoparticles Induce Human Mesenchymal Stem Cells to Express Distinct Extracellular Matrix Proteins Mediating Osteogenesis appeared first on Center for Integrative Nanotechnology Sciences.

Publication: BioResearch Open Access, Volume 9, Issue 1, 2020

Abstract: Effective graft technologies for bone repair have been a primary focus in the field of bone tissue engineering. We have previously fabricated and examined a nanocomposite composed of polyurethane, nano-hydroxyapatite, and decellularized bone particles, which demonstrated osteobiologic characteristics. To evaluate the underlying mechanisms of this biomaterial, human adipose-derived mesenchymal stem cell seeded scaffolds were assessed using a combinatorial approach of transcriptomic and metabolomic analyses. Data from osteogenic and signal transduction polymerase chain reaction arrays and small molecule abundances, measured through liquid chromatography–mass spectrometry, were cross-examined using Integrated Molecular Pathway Level Analysis, Database for Annotation, Visualization, and Integrated Discovery, and ConsensusPathDB online tools to generate a fundamental collection of scaffold-influenced pathways. Results demonstrated upregulation of key osteogenic, cellular adhesion cell signaling markers and indicated that Hedgehog and Wnt signaling pathways were primary candidates for the osteobiologic mechanisms of the scaffold design. The detection of complimentary metabolites, such as ascorbate, further indicates that scaffolds generate intricate cellular environments, promoting cell attachment and subsequent osteodifferentiation.

The post Multiomics evaluation of human fat-derived mesenchymal stem cells on an osteobiologic nanocomposite appeared first on Center for Integrative Nanotechnology Sciences.

Publication: ACS Omega 2020, Publication Date: January 21, 2020,

Abstract: A conducting polymer of lignosulfonic acid-grafted, polyaniline-doped camphorsulfonic acid (LS-PANI-CSA), created via a low-temperature solution process, has been explored as an efficient hole-transport layer (HTL) for inverted single cation–anion CH₃NH₃PbI₃ perovskite solar cells. The performance of the solar cell was optimized in this study by tuning the morphology and work function of LS-PANI-CSA films using dimethylsulfoxide (DMSO) as a solvent in treatment. Results showed that DMSO washing enhanced the electronic properties of the LS-PANI-CSA film and increased its hydrophobicity, which is very important for perovskite growth. The perovskite active layer deposited onto the DMSO-treated LS-PANI-CSA layer had higher crystallinity with large grain sizes (>5 ÎĽm), more uniform and complete surface coverage, and very low pinhole density and PbI₂ residues compared to untreated LS-PANI-CSA. These enhancements result in higher device performance and stability. Using DMSO-treated LS-PANI-CSA as an HTL at 15 nm of thickness, a maximum 10.8% power conversion efficiency was obtained in ITO/LS-PANI-CSA/MAPbI₃/PCBM/BCP/Ag inverted-device configurations. This was a significant improvement compared to 5.18% for devices based on untreated LS-PANI-CSA and a slight improvement over PEDOT:PSS-based devices with 9.48%. Furthermore, the perovskite based on treated LS-PANI-CSA showed the higher stability compared to both untreated LS-PANI-CSA and PEDOT:PSS HTL-based devices.

The post Optimizing Lignosulfonic Acid-Grafted Polyaniline as a Hole-Transport Layer for Inverted CH3NH3PbI3 Perovskite Solar Cells appeared first on Center for Integrative Nanotechnology Sciences.

Publication: ACS Appl. Bio Mater. 2019, 2, 5, 1815-1829

Abstract:

The complex dynamic nature of bone tissue presents a unique challenge for developing optimal biomaterials within the field of bone tissue engineering. Materials based on biological and physiological characteristics of natural bone have shown promise for inducing and promoting effective bone repair. Design of multicomposite scaffolds that incorporate both malleable and hard mineral components allows for intricate structures with nano- and macrosized mineral components to provide architectural elements that promote osteogenesis. The examined S-1 and S-2 scaffolds are multilayered constructs which differ only in the compositional ratio of nanohydroxyapatite (nHA) and decellularized bone particles (DBPs). The constructs incorporated previously studied nHA/polyurethane films interspersed with macrosized bone DBPs to stimulate integration with native tissue and induce osteogenic activity. In vitro assessment of cytocompatibility and osteostimulatory characteristics indicated that the scaffolds did not negatively impact cell health and demonstrated osteogenic effects. When the constructs were implanted in vivo, in a rat tibial defect model, the biocompatibility and osteogenic impact were confirmed. Material-treated defects were observed to not induce negative tissue reactions and, in those treated with S-1 scaffolds, exhibited greater levels of new bone formation. These results indicate that, while both scaffold designs were biocompatible, S-1 constructs demonstrate more effective biologically relevant nano-/macromineral architectural elements.

The post Evaluation of a polyurethane platform for delivery of nanohydroxyapatite and decellularized bone particles in a porous three-dimensional scaffold appeared first on Center for Integrative Nanotechnology Sciences.

Publication: RSC Advances, Issue 5

Abstract:

In this work, we present the first demonstration of tuning the work function of polyaniline by controlling the concentration level of camphorsulfonic acid as a protonic acid dopant and m-cresol as a solvent. Optical, thermal, structural, and electronic properties, along with surface topography and elemental analysis of protonated polyaniline, were studied in detail to investigate the effect of camphorsulfonic acid on the work function of polyaniline. The results showed that an increase in camphorsulfonic acid content induces a gradual transformation in the polyaniline structure from an emeraldine base to an emeraldine salt phase, which is associated with an increase in electrical conductivity and an improvement in crystallinity. X-ray photoelectron spectroscopy was used to evaluate the work function and to determine the elemental composition of the surface and several atomic layers beneath the surface. The results showed that increasing the camphorsulfonic acid content from quarter protonated to fully protonated leads to an increase in the work function of polyaniline from 4.42 ± 0.14 eV to 4.78 ± 0.13 eV.

The post Tuning the Work Function of Polyaniline via Camphorsulfonic Acid: An X-ray Photoelectron Spectroscopy Investigation appeared first on Center for Integrative Nanotechnology Sciences.