RSC Advances

Li, Qi-lin; Wu, Ya-xin; Zhang, Yu-xiao; Mao, Jing; Zhang, Zhi-xing

doi: 10.1039/d3ra05529apmid: 38179095

Periodontitis can lead to defects in the alveolar bone, thus increasing the demand for dependable biomaterials to repair these defects. This study aims to examine the pro-osteogenic and anti-bacterial properties of UPPE/β-TCP/TTC composites (composed of unsaturated polyphosphoester [UPPE], β-tricalcium phosphate [β-TCP], and tetracycline [TTC]) under an inflammatory condition. The morphology of MC3T3-E1 cells on the composite was examined using scanning electron microscopy. The toxicity of the composite to MC3T3-E1 cells was assessed using the Alamar-blue assay. The pro-osteogenic potential of the composite was assessed through ALP staining, ARS staining, RT-PCR, and WB. The antimicrobial properties of the composite were assessed using the zone inhibition assay. The results suggest that: (1) MC3T3-E1 cells exhibited stable adhesion to the surfaces of all four composite groups; (2) the UPPE/β-TCP/TTC composite demonstrated significantly lower toxicity to MC3T3-E1 cells; and (3) the UPPE/β-TCP/TTC composite had the most pronounced pro-osteogenic effect on MC3T3-E1 cells by activating the WNT/β-catenin pathway and displaying superior antibacterial properties. UPPE/β-TCP/TTC, as a biocomposite, has been shown to possess antibacterial properties and exhibit excellent potential in facilitating osteogenic differentiation of MC3T3-E1 cells.

Peng, Shan; Wu, Xiaolin; Sun, Yuanke; Zhou, Zhanxiang; Long, Debing; Yu, Huaqing

doi: 10.1039/d3ra08607kpmid: 38179098

The effects of zirconium doping on the thermodynamic, electronic, and optical properties of tin dioxide are investigated by using density functional theory calculations combined with the cluster expansion method. In the whole composition range, the formation enthalpies of all structures are positive, indicating that SnO2–ZrO2 is an immiscible system and the ZrSnO2 alloy has a tendency of phase separation at low temperature. The x-T phase diagram of ZrSnO2 ternary alloy shows that the critical temperature is 979 K, which means that when the growth temperature of ZrSnO2 crystal is higher than the critical temperature, it is possible to realize the full-component solid solution. The bandgaps of ZrxSn1−xO2 alloys (0 ≤ x ≤ 1) are direct and increase as the Zr composition increases. Zr doping can tune the bandgap of SnO2 from the ultraviolet-B region to the deep ultraviolet region, and has a strong optical response to deep ultraviolet light. The projected density of states and band offsets clearly reveal the reason for the increase of bandgap, which provides useful information to design relevant optoelectronic devices such as quantum wells and solar-blind deep ultraviolet photodetectors.

Sakunpongpitiporn, Phimchanok; Morarad, Rawita; Naeowong, Witthawat; Niamlang, Sumonman; Sirivat, Anuvat

doi: 10.1039/d3ra06857apmid: 38179091

In this study, silk fibroin (SF) was utilized as the starting material to fabricate physically crosslinked hydrogels. Poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS) was synthesized and characterized as a drug carrier, with insulin as the model drug. PEDOT:PSS, with a high electrical conductivity of 1666 ± 49 S cm−1, interacted with insulin molecules via electrostatic interaction by replacing the dopant PSS molecules. Insulin-loaded PEDOT:PSS embedded in the SF hydrogel resulted in an increase in the degree of swelling, pore size, and mesh size of the hydrogel. In the in vitro release and release-permeation experiments, the amounts of insulin release and release-permeation were investigated using a modified Franz diffusion cell, under the effects of SF concentrations, electric fields, and pH values. The amounts of insulin release and release-permeation from the pristine SF hydrogel and the PEDOT:PSS/SF hydrogel followed the power laws with the scaling exponents close to 0.5, indicating the Fickian diffusion or the concentration gradient. Under electric fields, with or without PEDOT:PSS used as the drug carrier, the insulin amount and diffusion coefficient were shown to increase with the increasing electric field due to the electro-repulsive forces between the cathode and insulin molecules and SF chains, electroosmosis, and SF matrix swelling. The SF hydrogel and PEDOT:PSS as the drug carrier are demonstrated herein as new components in the transdermal delivery system for the iontophoretically controlled insulin basal release applicable to diabetes patients.

Pandit, Pavan; Kong, Lingxue; Samuel, G. L.

doi: 10.1039/d3ra06431jpmid: 38179096

The advancement of microfluidics and the manufacturing of microdevices has led to a strategic change in the biomedical industry. The flow through narrow channels and the pillars are placed strategically, leading to the phenomenon of particle separation through deterministic lateral displacement (DLD). In such a phenomenon, the shape, size, location and orientation of the obstacles play an important role. For the first time, particle separation is achieved with DLD modules having high row shift angles of 25°, 30° and 35°, reducing the number of pillars. The significance of circular and triangular micropillars executing deterministic lateral displacement, oriented at different angles, has been investigated, and it is found that the triangular pillars oriented at 75° resulted in better separation compared to the other configurations. In this report, the fabrication, location, orientation of the micropillars and the selection of appropriate process parameters are detailed. The structures are fabricated on silicon wafers using the standard photolithography process followed by the deep reactive ion etching process. These dies are further used to fabricate the polydimethylsiloxane-based microfluidic chips. These fabricated devices are characterised by their size, structure and quality using 3D microscopy and scanning electron microscopy. Further, blood plasma separation is carried out using the devices fabricated in this work, and the particles at the inlet and outlets are evaluated using microscopy and a novel image processing technique, replacing the use of a hemocytometer. The path traced by the particles at different flow conditions is numerically evaluated and validated with experiments. The novel device is capable of separating blood cells from plasma with a recovery factor varying from 44% to 100%. PDMS–PDMS bonding experiments using oxygen and argon plasma have been carried out to evaluate the maximum bond strength and flow velocity in the devices. It is observed that the oxygen plasma results in a bond strength of 0.404 N mm−1, thus a high throughput of 135.34 μL s−1 is achieved using the fabricated device.

De Angelis, Martina; Managò, Marta; Pepi, Federico; Salvitti, Chiara; Troiani, Anna; Villani, Claudio; Ciogli, Alessia

doi: 10.1039/d3ra07975apmid: 38179090

The asymmetric synthesis of warfarin in microdroplets and thin films generated by an electrospray ionization (ESI) source is reported. This is one of the first examples of an enantioselective organocatalyzed reaction in electrosprayed confined volumes. The optimal conditions in terms of system setting were established for this reaction.

Mugheri, Abdul Qayoom; Ali, Kashif; Sangah, Ali Asghar; Khaskheli, Mazhar Iqbal; Laghari, Muhammad Younis; Mugheri, Nadeem Ahmed; Soomro, Muhammad Rajib; Chohan, Muhammad Ishfaq; Mugheri, Arsalan Ahmed; Kandhro, Aftab

doi: 10.1039/d3ra05126apmid: 38179100

In semiconductors, generating charges via catalysis is a highly challenging task and characteristic of heterojunction photoanodes. A dithiophene-4,8-dione spin-coated film layer has a positive effect on the holes (positive charge carriers) for a long time in BHJ films in the solid state of materials. The photoexcited holes created in the BHJ film can persist for long periods of time, which is beneficial for catalytic reactions. In this study, a photoanode is electrically coupled to a hydrogen gas-evolving platinum cathode. When the photoanode is electrically coupled to a H2 gas evolving Pt cathode, curiously long-lived hole polaron states are observed on the timescale of seconds under operational conditions. These long-lived holes play a crucial role in enhancing the hydrogen peroxide oxidation performance of the film overlayer spin-coated onto the photoanode. The spin-coated film overlayer on the photoanode achieves the best oxidation performance for hydrogen peroxide of approximately 6.5 mA cm−2 at 1.23 VRHE without the need of a catalyst. This demonstrates the effectiveness of the overlayer in improving the catalytic performance of the photoanode with a better efficiency of 17.5% when using 851 nm excitation. This indicates that a relatively high percentage of incident photons at that specific wavelength is converted into photocurrent by the photoanode. This approach can lead to more efficient oxidation catalysis as demonstrated in the case of hydrogen peroxide oxidation.

Haseen, Uzma; Ali, Syed Ghazanfar; Khan, Rais Ahmad; Alsalme, Ali; Koo, Bon Heun; Ahmad, Hilal

doi: 10.1039/d3ra05512dpmid: 38179094

In this study, we successfully synthesized polymeric graphitic carbon nitride (g-C3N4) nanosheets through thermal means and proposed their application in solid-phase extraction (SPE) for the enrichment of trace Hg(ii). The nanosheets underwent characterization using scanning electron microscopy, tunnelling electron microscopy, and energy-dispersive X-ray spectroscopy. The column packed with polymeric carbon nitride nanosheets demonstrated effective extraction of trace Hg(ii) ions from complex samples. The g-C3N4 nanosheets possess a zeta potential value of −20 mV, enabling strong interaction with positively charged divalent Hg(ii) ions. This interaction leads to the formation of stable chelates with the nitrogen atoms present in the polytriazine and heptazine units of the material. The proposed method exhibited a high preconcentration limit of 0.33 μg L−1, making it suitable for analysing trace amounts of Hg(ii) ions. Moreover, the method's applicability was confirmed through successful analysis of real samples, achieving an impressive preconcentration factor of 200. The detection limit for trace Hg(ii) ions was determined to be 0.6 μg L−1. To assess the accuracy of the method, we evaluated its performance by recovering spiked amounts of Hg(ii) and by analysing certified reference materials. The results indicated excellent precision, with RSD consistently below 5% for all the analyses conducted. In conclusion, the thermally synthesized polymeric carbon nitride nanosheets present a promising approach for solid-phase extraction and preconcentration of trace Hg(ii) from real samples. The method showcases high efficiency, sensitivity, and accuracy, making it a valuable tool for environmental and analytical applications.

Guo, Jialin; Zhang, Kai; Luo, Piao; Wu, Nanjie; Peng, Shigui; Wei, Lanlan; Liu, Yufei; He, Min; Yu, Jie; Qin, Shuhao; Fan, Qiao; Luo, Tingting; Xiao, Jun

doi: 10.1039/d3ra07334cpmid: 38179093

Poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) is widely used because of its excellent performance. We report the synthesis of two PEDOT:PSS dispersions. The two dispersions differ by the addition of additional protonic acid in the oxidative polymerization system. Although there are examples of the introduction of acids into the polymerization system, the effects of acid on the structure and properties of these materials, in particular their mechanisms of action, have not been elucidated. We describe the chemical structure and molecular weight of two PEDOT polymers using Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, UV-vis-NIR spectroscopy, and density functional theory calculations. The carrier concentration, carrier mobility, and surface morphology of the composites are characterized by UV-vis-NIR spectroscopy, electron spin resonance, Raman spectra, Hall effect measurements, and atomic force microscopy. The crystallinity of PEDOT:PSS was measured by X-ray diffraction patterns. We show that the addition of a proper amount of protonic acid to the oxidative polymerization system can effectively reduce the formation of the terminal carbonyl group of PEDOT chains, which is conducive to the growth of polymer chains, and further improve the carrier concentration, which leads to an improvement of conductivity. Our results highlight the optimization of the chemical structure of PEDOT in order to increase its molecular weight and ultimately its conductivity.

Araújo, Matheus Henrique Pimentel; Ardisson, José Domingos; Krohling, Alisson Carlos; Lago, Rochel Montero; Guimarães Júnior, Walber; Tristão, Juliana Cristina

doi: 10.1039/d3ra05871apmid: 38179099

In this study, calcium ferrites with different Ca : Fe atomic ratios (1 : 1, 1 : 2, 1 : 3 and 2 : 1) were prepared from Ca and Fe nitrates treated at 300, 700 and 900 °C and evaluated for phosphate adsorption and recovery from wastewater. TG, XRD, Mössbauer spectroscopy, SEM, VSM magnetic measurements, and BET analyses showed the formation of two different calcium ferrite phases, i.e., CaFe2O4 and Ca2Fe2O5 at 700 and 900 °C. The adsorption results indicated that the formation of calcium ferrite structure is critical for phosphate adsorption/recovery. Evaluation of the pH, initial phosphate concentration, contact time, coexisting ions and desorption conditions showed remarkable adsorption capacities of 62–75 mg g−1 for CaFe1:2-700 and 28–43 mg g−1 for CaFe1:2-900. The phosphate adsorption on the Ca ferrite surfaces is so strong that the recovery/desorption showed limited efficiencies, e.g., 15–39%.

Wang, Maorong; Yao, Ping; Gao, Minpeng; Jin, Jian; Yu, Yerong

doi: 10.1039/d3ra90124fpmid: 38179089

Retraction of ‘Novel fatty chain-modified GLP-1R G-protein biased agonist exerts prolonged anti-diabetic effects through targeting receptor binding sites’ by Maorong Wang et al., RSC Adv., 2020, 10, 8044–8053, DOI: https://doi.org/10.1039/C9RA10593J.