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In this study, a thermal battery is designed with vacuum insulation to improve its thermal insulation. Thermal insulation is one of the many factors that determine the stability and operation of the battery. The battery’s operating time as well as the improvement in its thermal insulation performance were analyzed. The location of the vacuum insulation was set as a variable in the analysis models. The thermal battery was subjected to unsteady heat transfer analysis until the electrolyte temperature reached 450°C. Vacuum insulation was applied to the part of the base thermal battery to fabricate three model batteries. Compared with the base model B, the operating time increased by 48% for the model BS, 76% for the model BSB, and 179% for the model BSBT. Due to the large area of the side, a large amount of heat was transferred; the quantity of heat transfer was in the order B>BS>BSB>BSBT. In the model BSBT, the heat loss per unit area was reduced by 93% at the side, top, bottom compared with the base model. The results of this study will serve as basic data for the design of thermal batteries with vacuum insulation and for improvement in insulation performance.

Limited light absorption beyond the UV region and rapid photocarrier recombination are critical impediments for the improved photocatalytic performance of carbon quantum dots (CQDs) under visible-light irradiation. Herein, we demonstrate single-step microwave-assisted syntheses of O-CQDs (typical CQDs terminated by carboxylic and hydroxyl functional groups) from a sucrose precursor and Cl-doped CQDs (Cl-CQDs) from a sucralose precursor in short reaction times and without using obligatory strong acids for Cl doping. The doping of Cl into the CQDs is observed to widen the absorption range and facilitate an enhanced separation of photoexcited charge carriers, which is confirmed by the results of optical absorption, photothermal response, and pump-probe ultrafast transient absorption spectroscopy measurements of the O-CQDs and Cl-CQDs. The photoexcited charge carriers with their longer lifetimes in Cl-CQDs enabled the quick degradation of methylene blue dye, rapid conversion of Ag+ ions to metallic Ag nanoparticles on the CQD surfaces, and reduction of GO to a well-dispersed rGO through the photoelectron transfer reactions under visible-light irradiation. The facile Cl doping strategy, hybridization of Ag nanoparticles or rGO to CQDs, and the elevated charge separation mechanism would open up new avenues in designing CQD-based materials for futuristic applications.

Enhancing therapeutic efficacy of drugs from reactive oxygen species (ROS) and glutathione (GSH)-responsive matrix and minimizing toxic effects on normal cells remains a challenge in programmable anticancer drug delivery. Herein, ROS- and GSH-responsive paclitaxel (PTX)-loaded polymer dot (PD) with mitochondria-targeting capability was designed by constructing diselenide linkage and triphenylphosphonium (TPP) for tunable PTX release and fluorescence for cancer theranostics. PD-TPP nanocarrier could improve the PTX stability after loading (PD-TPP(PTX)), and the cleavage of diselenide bond in the presence of H2O2 and GSH triggered the controllable PTX release, providing higher fluorescence intensity. As the levels of H2O2 and GSH are higher in cancer cells compared to normal cells, PTX was selectively released from PD-TPP in cancer cells, reducing cell viability (∼25%) and causing enhanced apoptosis of cancer cells compared to normal cells. The PD-TPP(PTX) selectivity was also reflected by distinct fluorescence intensity in HeLa and PC-3 cells (cancer) compared to CHO-K1 cells (normal). Furthermore, conjugated TPP promoted the PD-TPP(PTX) accumulation in mitochondria due to specific targeting of TPP towards mitochondria, allowing PTX release in mitochondria of cancer cells. Hence, this approach could be a potential strategy to enhance therapeutic efficacy of cancer drugs and minimize the side effects on normal cells.

In situ wireless monitoring for cell proliferation and detachment kinetics was conducted using pH-responsive zwitterionic polymer dots (Z-PDs), based on changes in electrochemical signals derived from Z-PD-coated substrates via the interaction of charges transferred between Z-PDs and cells. Z-PD-coated substrates were found to be a potent means to monitor and manipulate cell adhesion and detachment because of their high sensitivity over a wide range of pH conditions, and modification of the coated substrates was confirmed using a wireless system. At neutral pH, Z-PD-coated wireless sensors exhibited π-π stacking involving aromatic rings with hydrophobic interactions, thereby promoting cell proliferation; consequently, an increase in the measured resistance was observed. In contrast, Z-PD-coated substrates triggered by acidic and basic conditions promoted cell detachment, which induced an increase in the resistance compared with Z-PD substrates at pH 6.8, as a result of charges transferred to support Z-PD internalization through cell membranes after detachment. Therefore, as a wireless biosensor with excellent pH responsiveness that facilitates cell proliferation and detachment and whose electrochemical signals could be additionally acquired via a smartphone, Z-PD biosensors demonstrated a more favorable approach for monitoring cell-surface interactions than conventional optically based methods.

The reversible volume memories of the inner structures of soft materials with controllable hydrophilic-hydrophobic balance have been widely recognized, for example, hydrogels used in pressure sensors. Mechanical stimuli, such as pressure, vibration, and tensile, may influence the deformation of the hydrogel while simultaneously changing the electronic signal. Here, we designed a hydrophobic carbon dot nanoparticle (f-CD) mixed with polyvinyl alcohol and catechol-conjugated chitosan to obtain a hydrogel suitable for pressure and vibration sensor applications. The hydrophobicity of loaded f-CD plays an important role in mechanical performance and electronic signal acquisition. It also affects the different rheological reversibility and shape recovery as an impact on the volume transition. These characteristics are influenced by the compactness, dimensional structure, and density of the fabricated hydrogel. As a result, hydrogels with high hydrophobicity have a stiff structure (shear modulus 8123.1 N·m-2) compared to that of the hydrophilic hydrogel (ranging between 6065.7 and 7739.2 N·m-2). Moreover, the mechanically dependent volume transition hydrogel affects the electronic resistivity (up to 17.3 ± 1.3%) and capacitance change (up to 145%) when compressed with different forces. The hydrogel with a controlled hydrophobic-hydrophilic inner structure shows a unique sensitivity and great potential for various applications in wearable electronic skins, real-time clinical health-care monitoring, and human-computer interactions.

Polymer dot (PD)-bridged nickel cobalt oxide (NiCo2O4 (NCO)) nanoneedle-assembled globe-shaped clusters for high-performance glucose sensors were prepared via the consecutive calcination and packaging of PDs using the hydrothermal technique. The sp2-conjugated bridge of electrons, abundantly available catechol functionalized active sites offered by the PDs, and porous structure of NCO created effective electron transport routes for electrocatalytic reactions. The remarkable synergy between the conductive PDs and NCO conferred the PDs-bridged NCO (PDs-NCO) exceptional electrocatalytic activity for glucose detection. Under the optimal applied potential of +0.5 V, the developed PDs-NCO-coated Ni foam (NF) electrode presented the broad detection range from 5 μM to 0.25 mM, sensitivity of 806.17 μA mM−1 cm−2, detection limit of 2.75 μM, and exceptional selectivity. Furthermore, the PDs-NCO-coated NF electrode achieved the specific capacitance of 35.63 F g−1 at the current density of 0.5 A g−1 and superb cycling stability including the 96.7% specific capacitance retention over 5000 charge-discharge cycles. In addition, glucose-sensing could be easily monitored using a wireless sensor on a smartphone. The combination of NCO and PDs represents an innovative approach for constructing high-performance, reusable, non-enzymatic glucose sensors with low detection limit, high sensitivity, and excellent selectivity.

This study investigated a selective and sensitive theragnosis system for the specific targeting of the membrane and nuclei based on visible-light and pH-responsive TiO2-integrated cross-linked carbon dot (C-CD/TiO2) for tumor detection and controllable photothermal therapy. The cross-linking system was formed by boronate ester linkages between the TiO2-immobilized Dopa-decyl (D-CD) and zwitterionic-formed CD (Z-CD) for nuclear targeting, which showed fluorescence "off" at physiological pH. The fluorescence recovered to the "on" state in acidic cancer cells owing to cleavages of the boronate ester bonds, resulting in the disruption of the Forster resonance energy transfer that generated different CDs useful for tumor-selective biosensors and therapy. D-CD, which is hydrophobic, can penetrate the hydrophobic sites of the cell membrane; it caused a loss in the hydrophobicity of these sites after visible-light irradiation. This was achieved by the photocatalytic activity of the TiO2 modulating energy bandgap, whereas the Z-CD targeted the nucleus, as confirmed by merged confocal microscopy images. D-CD augmented by photothermal heat also exhibited selective anticancer activity in the acidic tumor condition but showed only minimal effects at a normal site at pH 7.4. After C-CD/TiO2 injection to an in vivo tumor model, C-CD/TiO2 efficiently ablated tumors under NIR light irradiation. The C-CD/TiO2 group showed up-regulation of the pro-apoptotic markers such as P53 and BAX in tumor. This material exhibited its potential as a theragnostic sensor with excellent biocompatibility, high sensitivity, selective imaging, and direct anticancer activity via photothermal therapy.

Recently, a great deal of research has focused on the study of self-healing hydrogels possessing electronic conductivity due to their wide applicability for use in biosensors, bioelectronics, and energy storage. The low solubility, poor biocompatibility, and lack of effective stimuli-responsive properties of their sp2 carbon-rich hybrid organic polymers, however, have proven challenging for their use in electroconductive self-healing hydrogel fabrication. In this study, we developed stimuli-responsive electrochemical wireless hydrogel biosensors using ureidopyriminone-conjugated gelatin (Gel-UPy) hydrogels that incorporate diselenide-containing carbon dots (dsCD) for cancer detection. The cleavage of diselenide groups of the dsCD within the hydrogels by glutathione (GSH) or reactive oxygen species (ROS) initiates the formation of hydrogen bonds that affect the self-healing ability, conductivity, and adhesiveness of the Gel-UPy/dsCD hydrogels. The Gel-UPy/dsCD hydrogels demonstrate more rapid healing under tumor conditions (MDA-MB-231) compared to that observed under physiological conditions (MDCK). Additionally, the cleavage of diselenide bonds affects the electrochemical signals due to the degradation of dsCD. The hydrogels also exhibit excellent adhesiveness and in vivo cancer detection ability after exposure to a high concentration of GSH or ROS, and this is comparable to results observed in a low concentration environment. Based on the combined self-healing, conductivity, and adhesiveness properties of the Gel-UPy/dsCD, this hydrogel exhibits promise for use in biomedical applications, particularly those that involve cancer detection, due to its selectivity and sensitivity under tumor conditions.

Stimulus-responsive polymers have been used in improving the efficacy of medical diagnostics through different approaches including enhancing the contrast in imaging techniques and promoting the molecular recognition in diagnostic assays. This review overviews the mechanisms of stimulus-responsive polymers in response to external stimuli including temperature, pH, ion, light, etc. The applications of responsive polymers in magnetic resonance imaging, capture and purification of biomolecules through protein-ligand recognition and lab-on-a-chip technology are discussed.

The overlap method is one of the most popular procedures for construction of an esophagojejunostomy and its common entry is usually closed with sutures. This study aimed to report long-term complications and surgical outcomes of the overlap method with stapled closure (OMSC), to compare them with those of laparoscopy-assisted total gastrectomy (LATG), and to analyze a learning curve.Between January 2015 and August 2017, 100 consecutive patients underwent laparoscopic total gastrectomy with OMSC for gastric cancer and the patients' medical records were reviewed. Their clinicopathologic characteristics, surgical outcomes, and long-term complications were investigated and compared with those of the LATG group. A learning curve of OMSC was analyzed using the Exponentially Weighted Moving Average chart.The overall duration of surgery was shorter in the LATG group; however, there was no difference in patients with early gastric cancer. Hospital admission was shorter and the pain scale was lower in the OMSC group. There was no difference in the number of harvested lymph nodes, date of flatus, or incidence of postoperative morbidity. Both groups showed no duodenal stump leakage, anastomosis-related complications, recurrence, or mortality during the follow-up period. Petersen hernia was a notable long-term event following OMSC compared with LATG. At least 27 cases of surgery were required to reach a plateau in terms of surgery duration for OMSC.OMSC is a safe option for the treatment of gastric cancer and has favorable long-term results and surgical outcomes. Closure of mesenteric defects and Petersen space should be considered.

The present study aimed to develop a bio-adhesive material with excellent hemostatic and rapid wound healing properties using a catechol moiety (2chloro-3′,4′-dihydroxyacetophenone) conjugated to poly(dimethyl amino ethyl methacrylate-co-t-butyl methacrylate) [poly(DMA-co-t-BMA)-2-chloro-3′,4′-dihydroxyacetophenone (CA), C-PDB]. The desired glue matrix was formed by crosslinking between C-PDB and chitosan via the Michael addition reaction. During glue matrix formation, chitosan plays a vital role as a cross-linker because the amine group of chitosan can easily react with the quinone from CA, based on catechol chemistry under mild alkaline conditions. Lap shear strength tests showed that the formulated glue matrix had a significant adhesive force at around 1.288 MPa and it formed quickly in vitro. In addition, when applied on a bleeding site on a rat aorta in vivo, the prepared glue matrix displayed strong hemostatic behavior. Hematoxylin and eosin (H&E), Masson’s trichrome, and reticulin staining of wounds (hepatic tissue) treated with the prepared glue matrix displayed rapid wound healing. Therefore, the prepared glue matrix is a potential candidate as a hemostatic and wound-healing agent for clinical applications.

Light‐based therapy such as photobiomodulation (PBM) reportedly produces beneficial physiological effects in cells and tissues. However, most reports have focused on the immediate and instant effects of light. Considering the physiological effects of natural light exposure in living organisms, the latent reaction period after irradiation should be deliberated. In contrast to previous reports, we examined the latent reaction period after light exposure with optimized irradiating parameters and validated novel therapeutic molecular mechanisms for the first time. we demonstrated an organic light‐emitting diode (OLED)‐based PBM (OPBM) strategy that enhances the angiogenic efficacy of human adipose‐derived stem cells (hADSCs) via direct irradiation with red OLEDs of optimized wavelength, voltage, current, luminance, and duration, and investigated the underlying molecular mechanisms. Our results revealed that the angiogenic paracrine effect, viability, and adhesion of hADSCs were significantly intensified by our OPBM strategy. Following OPBM treatment, significant changes were observed in HIF‐1α expression, intracellular reactive oxygen species levels, activation of the receptor tyrosine kinase, and glycolytic pathways in hADSCs. In addition, transplantation of OLED‐irradiated hADSCs resulted in significantly enhanced limb salvage ratio in a mouse model of hindlimb ischemia. Our OPBM might serve as a new paradigm for stem cell culture systems to develop cell‐based therapies in the future.

Limited light absorption beyond the UV region and rapid photocarrier recombination are critical impediments for the improved photocatalytic performance of carbon quantum dots (CQDs) under visible-light irradiation. Herein, we demonstrate single-step microwave-assisted syntheses of O-CQDs (typical CQDs terminated by carboxylic and hydroxyl functional groups) from a sucrose precursor and Cl-doped CQDs (Cl-CQDs) from a sucralose precursor in short reaction times and without using obligatory strong acids for Cl doping. The doping of Cl into the CQDs is observed to widen the absorption range and facilitate an enhanced separation of photoexcited charge carriers, which is confirmed by the results of optical absorption, photothermal response, and pump-probe ultrafast transient absorption spectroscopy measurements of the O-CQDs and Cl-CQDs. The photoexcited charge carriers with their longer lifetimes in Cl-CQDs enabled the quick degradation of methylene blue dye, rapid conversion of Ag

Development of simultaneous bacteria detection and eradication with simple, rapid, and reusable material is important in addressing bacterial contamination issues. In this study, we utilized the expression of alkaline phosphatase (ALP) from bacteria to design fluorescence ON/OFF system for bacteria detection, also using metal oxide nanoparticle for obtaining antibacterial activity and recyclability. The fluorescent-based biosensor with antibacterial activity was prepared by intercalating ALP-sensitive polymer dot (PD) containing β-cyclodextrin (β-CD) onto montmorillonite (MMT) as loading matrix via ionic exchange reaction, followed by immobilization of magnetic iron oxide (Fe3O4) and NIR-responsive cesium tungsten oxide (CsWO3). The PD-βCD-MMT/Fe3O4–CsWO3 nanocomposite exhibited strong fluorescence intensity, which was quenched in the presence of bacterial ALP (0–1000 U/L) due to hydrolysis of p-nitrophenyl phosphate (NPP) into p-nitrophenol (NP) in the hydrophobic site of β-CD. Furthermore, the nanocomposite could detect both gram-negative Escherichia coli and gram-positive Staphylococcus aureus in the range of 101–107 CFU/mL (LOD 5.09 and 4.62 CFU/mL, respectively), and showed high antibacterial activity against bacteria by generating photothermal heat under 5 min NIR irradiation, causing damage to bacterial cells. This material also demonstrated recyclability via magnetic field exposure due to the presence of Fe3O4. In addition, the fluorescence can be recovered following pH shock and re-conjugation of β-CD molecules. After 4 cycles, nanocomposite still showed stable photothermal effects and fluorescence-based bacteria detection. Thus, this reusable material offers promising approach for simultaneous bacteria detection and killing, which is simple, rapid, and effective.

Using pH-switchable fluorescent polymer dots (PD) by means of fluorescent, colorimetric, and electrochemical signals generated from surfaces coated with PD of zwitterionic structure provided a fast and easy method to assess their performance in mammalian cell and bacterial interactions. The PD-coated surfaces showed high sensitivity over a broad range of pH levels by switching reversibly zwitterionic states, which led to an excellent cellular resistance effect by inhibiting the attachment of nearly 95% of mammalian cells. Similarly, they exhibited a strong interaction with the negatively charged surfaces of bacteria, as observed in the fluorescence ON/OFF system. In addition, PD were employed to detect the attachment of mammalian and bacterial cells: we deposited PD on a screen-printed carbon electrode for cyclic voltammetry analysis. Notably, the presence of cells remarkably interfered with the current flow between the PD and the screen-printed carbon electrode surface by causing an impressive decline in both reduction-oxidation signals, implying the high sensitivity of the PD-coated surfaces to cells and bacteria in different pH environments. Therefore, as smart materials with high sensitivity, biocompatibility, selectivity, and accuracy, PD-coated surfaces represent a promising approach to visualizing and controlling biological cell attachment, thereby helping to avoid contamination in biomedical applications.

A redox-responsive fluorescent carbon nanogel (FCN) was designed as a bioimaging probe for targeted drug delivery to cancer cells. FCN was synthesized by the carbonization of disulfide cross-linked hyaluronic acid in the fluorescence “on” mode, followed by the attachment of manganese oxide (MnO2) nanosheets for fluorescence quenching (fluorescence “off”). We hypothesized that the fluorescence intensity of paclitaxel (PTX)-MnO2/FCN would suddenly increase (fluorescence “on”) in the presence of a high level of glutathione (GSH) in cancer cells, owing to the reduction of MnO2 to Mn2+ and cleavage of the disulfide bond. Consequently, PTX would be released from the FCN system. Consistent with this hypothesis, the designed system recovered FCN fluorescence and triggered drug release through the cleavage of the disulfide bond by GSH. Moreover, PTX-MnO2/FCN demonstrated stable fluorescence intensity after GSH treatment, serving as a potential biosensor. PTX-MnO2/FCN exhibited excellent biocompatibility with normal cells and selectively targeted tumor cells, highlighting the therapeutic capabilities of this system. The developed PTX-MnO2/FCN structure may serve as a smart drug delivery system with diagnostic and therapeutic properties, good selectivity, and compatibility, and with excellent potential for biomedical applications.

We developed a highly pH-sensitive fluorescent carbon dot probe containing IR825 photothermal dye for rapid detection of environmental bacteria, with subsequent killing activity via near-infrared (NIR) driven photothermal ablation. The IR825-loaded fluorescent carbon dot (I-CD) interacted strongly with the negative charge of bacterial surface, expressed via fluorescence ON/OFF behavior under a broad range of pH conditions, by modifying the zwitterionic conformation of the carbon dot. In acidic and basic conditions, I-CD is activated, losing its hydrophobicity in neutral condition and releasing IR825, inducing NIR-mediated photothermal activity. Release of IR825 from the I-CD core contributed to high thermal conversion, killing bacterial cells with 99% efficiency. This material shows potential to be used as a convenient, rapid, low-cost, high-sensitivity fluorescent bacterial biosensor, combined with effective bacterial killing activity via photothermal conversion with pH and NIR triggers.

Highly water-dispersible and strongly near IR absorbing chemically reduced graphene oxide (rGO)/CP750 assembly was firstly prepared through noncovalent approach from graphene oxide (GO) and CP750, a cyclotriphosphazene ring-based tripodal amphiphile. Through the stable noncovalent interaction by tripodal CP750 amphiphiles, rGO/CP750 assembly presented both high absorption coefficient of 2260 L g−1 m−1 and high near infrared (NIR) absorbance (1.07 at rGO concentration of 0.05 wt.%) in aqueous media without forming precipitates for a long term storage. Upon NIR laser (808 nm) irradiation, rGO/CP750 presented high photothermal heat generating ranging from +34.1 to +78.0 °C depending on the assembly concentration. Finally, excellent photothermal bactericidal performance of nearly 100% was accomplished toward both E. coli and S. aureus even at a low concentration of assembly (0.1 mg/mL) within 10 min of NIR irradiation. In overall, our study shows that high photothermal bactericidal performance that has been mainly claimed by other strongly NIR absorbing nanomaterials such as gold nanorods and semiconducting polymers can be easily accomplished from rGO-based nanomaterials with the proper utilization of tripodal amphiphiles.

The reversible volume transition of redox-responsive hydrogels by near-infrared (NIR) irradiation has recently attracted significant attention as a novel therapy matrix for tracking and treating cancer via stimuli-responsive fluorescence on/off with controllable volume transition via a wireless sensing system. Herein, a NIR-induced redox-sensitive hydrogel was synthesized by blending a hydrogel with IR825-loaded carbon dots (CD) to achieve enhanced mobility of nanoparticles inside a gel network, and reversible volume phase transitions remotely controlled by a smartphone application via the induction of different redox environments. The presence of CD-IR825 in the thermosensitive poly(N-isopropylacrylamide) hydrogel network imparted fluorescence, electronic and photothermal properties to the hydrogels, which resulted in volume shrinkage behavior of the hydrogel upon exposure to NIR laser irradiation due to the redox-sensitive CDs. Under the NIR on/off cycles, the photothermal temperature, fluorescence, and porous structure were reversed after turning off the NIR laser. The hydrogel responsiveness under GSH and NIR light was studied using a wireless device based on the changes in the resistance graph on a smartphone application, generating a fast and simple method for the investigation of hydrogel properties. The in vitro cell viabilities of the MDA-MB cancer cells incubated with the composite hydrogel in the presence of external GSH exhibited a higher photothermal temperature, and the cancer cells were effectively killed after the NIR irradiation. Therefore, the NIR-induced redox-responsive nanocomposite hydrogel prepared herein has potential for use in cancer treatment and will enable the study of nanoparticle motion in hydrogel networks under multiple stimuli via a wireless device using a faster and more convenient method.

Underwater exercise programs are among the nursing programs for which positive effects have been reported with regard to the promotion of good health in diverse subjects, such as patients suffering arthritis, as well as elderly people and middle-aged women. Through many previously conducted studies, subjects participating in underwater exercises have been reported to continuously experience reduced pain, and improvement in muscle strength, flexibility, sense of balance, and muscular endurance. However, few studies have delved into the fundamental phenomena of positive effects of underwater exercises on the human body. In this study, a model of the upper limbs of the human body was used in a simulation of underwater exercises to analyse the resulting pressure fluctuation on the skin of the hands and arms of the model through the methods of computational fluid dynamics. During the simulation of underwater exercises, pressure fluctuation of diverse frequencies, arising from the vortex flow around the articulations of the fingers and hands of the model, were identified and were seen to create varied cutaneous stimulations and massage effects. Such cutaneous stimulations seem to continuously excite capillary vessels situated between hands and finger joints, creating positive effects in blood circulation around pain sites of patients suffering from arthritis.

Here, we designed a pH-responsive Indocyanine Green (ICG)-loaded zwitterion fluorescent carbon dot (CD)-encapsulating mesoporous silica nanoparticle (MSN) for pH-tunable image-guided photothermal therapy. ICG was loaded into MSN(CD) via hydrophobic and electrostatic interactions between zwitterionic CDs and ICG to achieve a controlled photothermal temperature with a fluorescent "off/on" system. The porosity of the MSNs was altered after ICG loading because of intermolecular interactions between the CDs and ICG inside the MSN shell and core, which blocked the MSN pore. The acidic environment pH affected the fluorescent signals of the ICG-MSN(CD), reflecting the "off-on" characteristics of the synthesized MSN, which then induced the release of ICG from the matrices. Moreover, the photothermal conversion of ICG-MSN(CD) showed sufficient heat generation to kill cancer cells at an acidic pH with low-temperature elevation at physiological pH. ICG-MSN(CD) demonstrated good cell viability of MDA-MB-231 cells without irradiation; however, high necrosis was observed when the environment was adjusted to acidic pH and after near-infrared irradiation. These pH-responsive photothermal mesoporous silica nanoparticles may have applications in biomedicine, particularly for cancer treatment.