RESUMEN
The recent boom of nanomaterials printing in the fields of biomedical engineering, bioanalysis and flexible electronics has greatly stimulated researchers' interest in printing technologies. However, specifically formulated nanomaterial inks have limited the types of printable nanomaterials. Here, a unique non-powered capillary force-driven stamped (CFDS) approach, combining a 3D-printed stamper with a paper substrate, is developed for directly printing patterned nanomaterials aqueous solution. The CFDS approach has two processes, including the loading process in which the capillary force of the stamper channel is stronger than gravity, and the deposition process, in which the synergistic action of the capillary force of the paper fibre tubes and gravity is approximately 20 times the capillary force of the stamper channel. Four additive-free nanomaterial aqueous solutions, including nanowires, nanosheets, nanostars and nanogels, are used to print patterns, and show slight diffusion and desired uniformity with a diffusion rate and roundness of 1.12 and 0.78, respectively, demonstrating the feasibility of this approach. Four kinds of nanogel with different fluorescence labels are simultaneously printed to challenge the approach and demonstrate its flexibility and scalability. The resolution of the approach is 0.3 mm. Without any post-processing, the stamped paper substrates directly serve as paper-based surface enhanced Raman scattering substrates with an enhancement factor of 4 × 106 and as electrodes with a resistance of 0.74 Ω, demonstrating their multi-functionality. Due to its general, flexible and scalable applicability, this simple, low-cost and non-powered approach could be widely applied to the personalized printing of nanomaterials on paper substrates.
RESUMEN
Alginate as a good drug delivery vehicle has excellent biocompatibility and biodegradability. In the ionic gelation process between alginate and Ca2+, the violent reaction is the absence of a well-controlled strategy in the synthesizing calcium alginate (CaA) microgels. In this study, a concentration-controlled microfluidic chip with central buffer flow was designed and 3D-printed to well-control the synthesis process of CaA microgels by the diffusion mixing pattern. The diffusion mixing pattern in the microfluidic chip can slow down the ionic gelation process in the central stream. The particle size can be influenced by channel length and flow rate ratio, which can be regulated to 448 nm in length and 235 nm in diameter. The delivery ratio of Doxorubicin (Dox) in CaA microgels are up to 90% based on the central stream strategy. CaA@Dox microgels with pH-dependent release property significantly enhances the cell killing rate against human breast cancer cells (MCF-7). The diffusion mixing pattern gives rise to well-controlled synthesis of CaA microgels, serving as a continuous and controllable production process for advanced drug delivery systems.
RESUMEN
Photodynamic therapy (PDT) and fluorescence imaging offer the possibility of precise and personalized treatment of cancer, but low singlet oxygen production of a commercial photosensitizer and the quenching effect of fluorescent dyes limit the further application of PDT treatment and fluorescence imaging. In addition, the single nanoplatform that simultaneously achieved singlet oxygen and fluorescence enhancement is rare. In this paper, a novel simultaneously enhanced singlet oxygen and fluorescence production nanoplatform of AuNR@mSiO2-Ce6-Cy5.5 has been successfully designed and synthesized by surface plasmon resonance coupling. The as-synthesized nanoplatform achieved a 1.8-fold enhancement of the singlet oxygen production of Ce6 and a 5.0-fold enhancement of the fluorescence production of Cy5.5 by surface plasmon resonance coupling. The as-synthesized nanoplatform simultaneously enhances the photodynamic therapy and fluorescence imaging of cancer, which will have great potential in biomedical applications.
RESUMEN
Cell detection is of great significance for biomedical research. Surface enhanced Raman scattering (SERS) has been widely applied to the detection of cells. However, there is still a lack of a general, low-cost, rapid, and sensitive SERS method for cell detection. Herein, a dynamic liquid SERS platform, which combines label-free SERS technique with soft tubular microfluidics for cell detection, is proposed. Compared with common static solid and static liquid measurement, the dynamic liquid SERS platform can present dynamical mixing, precise control of the mixing time, and continuous spectra collection. By characterizing the model molecules, the proposed dynamic liquid SERS platform has successfully demonstrated good stability and repeatability with 1.90% and 4.98% relative standard deviation (RSD), respectively. Three cell lines including one normal breast cell line (MCF-10A) and two breast cancer cell lines (MCF-7 and MDA-MB-231) were investigated in this platform. 270 cell spectra were selected as the training set for the classification of the models based on the K-Nearest Neighbor (K-NN) algorithm. In three independent experiments, three types of cells were identified by a test set containing 180 cell spectra with sensitivities above 83.3% and specificities above 91.6%. The accuracy was 94.1 ± 1.14% among three independent cell identifications. The dynamic liquid SERS platform has shown higher signal intensity, better repeatability, less pretreatment, and obtainment of more spectra with less time consumption. It will be a powerful detection tool in the area of cell research, clinical diagnosis, and food safety.