Unexpected omega-3 activities in intracellular lipolysis and macrophage foaming revealed by fluorescence lifetime imaging.

Omega-3 polyunsaturated fatty acids (PUFA) found primarily in fish oil have been a popular supplement for cardiovascular health because they can substantially reduce circulating triglyceride levels in the bloodstream to prevent atherosclerosis. Beyond this established extracellular activity, here, we report a mode of action of PUFA, regulating intracellular triglyceride metabolism and lipid droplet (LD) dynamics. Real-time imaging of the subtle and highly dynamic changes of intracellular lipid metabolism was enabled by a fluorescence lifetime probe that addressed the limitations of intensity-based fluorescence quantifications. Surprisingly, we found that among omega-3 PUFA, only docosahexaenoic acid (DHA) promoted the lipolysis in LDs and reduced the overall fat content by approximately 50%, and consequently helped suppress macrophage differentiation into foam cells, one of the early steps responsible for atherosclerosis. Eicosapentaenoic acid, another omega-3 FA in fish oil, however, counteracted the beneficial effects of DHA on lipolysis promotion and cell foaming prevention. These in vitro findings warrant future validation in vivo.

Synchronous Photoactivation-Imaging Fluorophores Break Limitations of Photobleaching and Phototoxicity in Live-cell Microscopy.

Fluorescence microscopy is one of the most important tools in the studies of cell biology and many other fields, but two fundamental issues, photobleaching and phototoxicity, associated with the fluorophores have still limited its use for long-term and strong-illumination imaging of live cells. Here, we report a new concept of fluorophore engineering chemistry, synchronous photoactivation-imaging (SPI) fluorophores, activating and exciting fluorophores by a single light source to thus avoid the repeated switches between activation and excitation lights. The chemically reconstructed, nonemissive fluorophores can be photolyzed to allow continuous replenishing of "bright-state" probes detectable by standard fluorescent microscopes in the imaging process so as to bypass the photobleaching barrier to greatly extend the imaging period. Equally importantly, SPI fluorophores substantially reduce photocytotoxicity due to the scavenging of reactive oxygen species (ROS) by a photoactivable group and the slow release of "bright-state" probes to minimize ROS generation. Using SPI fluorophores, the time-lapsed confocal (>16 h) and super-resolution (>3 h) imaging of subcellular organelles under intensive illumination (50 MW/cm2) were achieved in live cells.

Short-Wave Infrared Quantum Dots with Compact Sizes as Molecular Probes for Fluorescence Microscopy.

Materials with short-wave infrared (SWIR) emission are promising contrast agents for in vivo animal imaging, providing high-contrast and high-resolution images of blood vessels in deep tissues. However, SWIR emitters have not been developed as molecular labels for microscopy applications in the life sciences, which require optimized probes that are bright, stable, and small. Here, we design and synthesize semiconductor quantum dots (QDs) with SWIR emission based on HgxCd1-xSe alloy cores red shifted to the SWIR by epitaxial deposition of thin HgxCd1-xS shells with a small band gap. By tuning alloy composition alone, the emission can be shifted across the visible-to-SWIR (VIR) spectra while maintaining a small and equal size, allowing direct comparisons of molecular labeling performance across a broad range of wavelength. After coating with click-functional multidentate polymers, the VIR-QD spectral series has high quantum yield in the SWIR (14-33%), compact size (13 nm hydrodynamic diameter), and long-term stability in aqueous media during continuous excitation. We show that these properties enable diverse applications of SWIR molecular probes for fluorescence microscopy using conjugates of antibodies, growth factors, and nucleic acids. A broadly useful outcome is a 10-55-fold enhancement of the signal-to-background ratio at both the single-molecule level and the ensemble level in the SWIR relative to visible wavelengths, primarily due to drastically reduced autofluorescence. We anticipate that VIR-QDs with SWIR emission will enable ultrasensitive molecular imaging of low-copy number analytes in biospecimens with high autofluorescence.

Multifunctional Conjugated Polymer Nanoparticles for Image-Guided Photodynamic and Photothermal Therapy.

A multifunctional theranostic platform based on conjugated polymer nanoparticles (CPNs) with tumor targeting, fluorescence detection, photodynamic therapy (PDT), and photothermal therapy (PTT) is developed for effective cancer imaging and therapy. Two conjugated polymers, poly[9,9-bis(2-(2-(2-methoxyethoxy)ethoxy)-ethyl)fluorenyldivinylene]-alt-4,7-(2,1,3-benzothiadiazole) with bright red emission and photosensitizing ability and poly[(4,4,9,9-tetrakis(4-(octyloxy)phenyl)-4,9-dihydro-s-indacenol-dithiophene-2,7-diyl)-alt-co-4,9-bis(thiophen-2-yl)-6,7-bis(4-(hexyloxy)phenyl)-thiadiazolo-quinoxaline] with strong near-infrared absorption and excellent photothermal conversion ability are co-loaded into one single CPN via encapsulation approach using lipid-polyethylene glycol as the matrix. The obtained co-loaded CPNs show sizes of around 30 nm with a high singlet oxygen quantum yield of 60.4% and an effective photothermal conversion efficiency of 47.6%. The CPN surface is further decorated with anti-HER2 affibody, which bestows the resultant anti-HER2-CPNs superior selectivity toward tumor cells with HER2 overexpression both in vitro and in vivo. Under light irradiation, the PDT and PTT show synergistic therapeutic efficacy, which provides new opportunities for the development of multifunctional biocompatible organic materials in cancer therapy.

Biocompatible conjugated polymer nanoparticles for efficient photothermal tumor therapy.

Conjugated polymers (CPs) with strong near-infrared (NIR) absorption and high heat conversion efficiency have emerged as a new generation of photothermal therapy (PTT) agents for cancer therapy. An efficient strategy to design NIR absorbing CPs with good water dispersibility is essential to achieve excellent therapeutic effect. In this work, poly[9,9-bis(4-(2-ethylhexyl)phenyl)fluorene-alt-co-6,7-bis(4-(hexyloxy)phenyl)-4,9-di(thiophen-2-yl)-thiadiazoloquinoxaline] (PFTTQ) is synthesized through the combination of donor-acceptor moieties by Suzuki polymerization. PFTTQ nanoparticles (NPs) are fabricated through a precipitation approach using 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-[methoxy(polyethylene glycol)-2000] (DSPE-PEG2000 ) as the encapsulation matrix. Due to the large NIR absorption coefficient (3.6 L g(-1) cm(-1) ), the temperature of PFTTQ NP suspension (0.5 mg/mL) could be rapidly increased to more than 50 °C upon continuous 808 nm laser irradiation (0.75 W/cm(2) ) for 5 min. The PFTTQ NPs show good biocompatibility to both MDA-MB-231 cells and Hela cells at 400 µg/mL of NPs, while upon laser irradiation, effective cancer cell killing is observed at a NP concentration of 50 µg/mL. Moreover, PFTTQ NPs could efficiently ablate tumor in in vivo study using a Hela tumor mouse model. Considering the large amount of NIR absorbing CPs available, the general encapsulation strategy will enable the development of more efficient PTT agents for cancer or tumor therapy.

Fluorogens with Aggregation Induced Emission: Ideal Photoacoustic Contrast Reagents Due to Intramolecular Rotation.

Exogenous contrast agents with high sensitivity are highly desirable for photoacoustic (PA) imaging. In this work, we show that fluorogens with aggregation induced emission (AIE) characteristics are born with strong PA signals. In addition, we find that the PA signal of conventional fluorophores could be significantly enhanced through conjugation with tetraphenylethene (TPE), an iconic AIE fluorogen. Taking 2,3-bis[4-(diphenylamino)phenyl]fumaronitrile (TPAFN) as an example, conjugation between TPAFN and TPE affords 2,3-bis(4-(phenyl(4-(1,2,2-triphenylvinyl)phenyl)amino)phenyl) fumaroni-trile (TPETPAFN), a molecule with significant AIE characteristics, which shows 170% higher PA signals as compared to that of TPAFN. The higher PA signal of TPETPAFN is mainly ascribed to the enhanced molecular rotation, which is beneficial to its thermal expansion upon light absorption. Moreover, the significantly reduced PA signals for TPETPAFN in solvents with high viscosity or as nanoparticles further highlight the contribution of molecular rotation on PA signals.

Eccentric loading of fluorogen with aggregation-induced emission in PLGA matrix increases nanoparticle fluorescence quantum yield for targeted cellular imaging.

A simple strategy is developed to prepare eccentrically or homogeneously loaded nanoparticles (NPs) using poly (DL-lactide-co-glycolide) (PLGA) as the encapsulation matrix in the presence of different amounts of polyvinyl alcohol (PVA) as the emulsifier. Using 2,3-bis(4-(phenyl(4-(1,2,2-triphenylvinyl)-phenyl)amino)-phenyl)-fumaronitrile (TPETPAFN), a fluorogen with aggregation-induced emission (AIE) characteristics, as an example, the eccentrically loaded PLGA NPs show increased fluorescence quantum yields (QYs) as compared to the homogeneously loaded ones. Field emission transmission electron microscopy and fluorescence lifetime measurements reveal that the higher QY of the eccentrically loaded NPs is due to the more compact aggregation of AIE fluorogens that restricts intramolecular rotations of phenyl rings, which is able to more effectively block the non-radiative decay pathways. The eccentrically loaded NPs show far red/near infrared emission with a high fluorescence QY of 34% in aqueous media. In addition, by using poly([lactide-co-glycolide]-b-folate [ethylene glycol]) (PLGA-PEG-folate) as the co-encapsulation matrix, the obtained NPs are born with surface folic acid groups, which are successfully applied for targeted cellular imaging with good photostability and low cytotoxicity. Moreover, the developed strategy is also demonstrated for inorganic-component eccentrically or homogeneously loaded PLGA NPs, which facilitates the synthesis of polymer NPs with controlled internal architectures.

Online Quantitative Analysis of Chlorine Contents in Chlorinated Paraffins by Facile Raman Spectroscopy.

Online analysis of industrial chemicals is extremely important for managing product quality and performance. The chlorine (Cl) content is one of the most important technical metrics for chlorinated paraffins (CPs), and the conventional approaches to estimate Cl contents require transforming the Cl element to chloride followed by quantitative analysis with either titration or instrumentation, which are normally tedious and time-consuming and cannot simultaneously guide the industrial production. Here, we developed a rapid, real-time, and online approach to determine the Cl content of CPs with facile Raman spectroscopy. The chlorination of paraffins generated two new Raman peaks at 610-618 and 668-690 cm-1, which are associated with the vibrational modes of the SHH and SHC conformations of the C-Cl bond in CPs, respectively. More importantly, the corresponding peak of the SHH conformation decreased and that of the SHC conformation increased with the enhancement of the chlorination degree of CPs. The ratiometric calculation of the two respective Raman peak areas leads to a quantitative analysis of the Cl content of CPs. The developed approach can online provide the Cl contents of CPs within seconds accurately but without the tedious sample treatment required by conventional approaches. The strategy of integrating Raman analysis with the industrial pipeline will help in managing the production and quality control of industrial chemicals.

A viscosity-sensitivity probe for cross-platform multimodal imaging from mitochondria to animal.

Viscosity in biological systems is a critical factor for various physiological process, including signal transduction and metabolisms of substance and energy. Abnormal viscosity has been proven as a key feature of many diseases, thereby real-time monitoring of viscosities in cells and in vivo is of great significance for the diagnosis and therapy of related diseases. Up to date, it is still challenging to monitor viscosity cross-platform from organelles to cells to animals with a single probe. Here, we report a benzothiazolium-xanthene probe with rotatable bonds that switch on the optical signals in high viscosity environment. The enhancements of absorption, fluorescence intensity and lifetime signals allow to dynamically monitoring the viscosity change in mitochondria and cells, while near infrared absorption and emission facilitate imaging the viscosity with both fluorescence and photoacoustic imaging in animals. The cross-platform strategy is capable of monitoring the microenvironment with multifunctional imaging across various levels.

Specific detection of integrin αvß3 by light-up bioprobe with aggregation-induced emission characteristics.

Specific bioprobes with fluorescence turn-on response are highly desirable for high contrast biosensing and imaging. In this work, we developed a new generation bioprobe by integrating tetraphenylsilole, a fluorogenic unit with aggregation-induced emission (AIE) characteristic, with cyclic arginine-glycine-aspartic acid tripeptide (cRGD), a targeting ligand to integrin α(v)ß(3) receptor. Emission of the AIE probe is switched on upon its specific binding to integrin α(v)ß(3), which allows quantitative detection of integrin α(v)ß(3) in solution and real-time imaging of the binding process between cRGD and integrin α(v)ß(3) on cell membrane. The probe can be used for tracking integrin α(v)ß(3) and for identifying integrin α(v)ß(3)-positive cancer cells.

Conjugated polymer and gold nanoparticle co-loaded PLGA nanocomposites with eccentric internal nanostructure for dual-modal targeted cellular imaging.

Herein is reported the one-step synthesis of an integrated nanocomposite with eccentrically loaded 5 nm gold nanoparticles (Au NPs) and conjugated polymer of poly[9,9-bis(6'-N,N,N-trimethylammonium)hexyl)fluorenyldivinylene-alt-4,7-(2,1,3,- benzothiadiazole) dibromide] (PFVBT). The nanocomposite is generated with surface-functionalized folic acid groups due to the matrix polymer of PLGA-PEG(2000) -folate used for encapsulation. The nanocomposite shows far-red fluorescence from PFVBT and scattering signal from Au NPs. Although Au NPs have been widely reported to quench the fluorescence of conjugated polymers, the PFVBT fluorescence is well maintained in the nanocomposite due to the eccentric location of Au NPs. The folic acid groups at the nanocomposite surface favor its cellular uptake by MCF-7 breast cancer cells, which have overexpressed folate receptors on the cell membranes. In conjugation with its low cytotoxicity, the folic-acid-functionalized nanocomposite has been successfully utilized for fluorescence and dark-field dual-modal targeted cellular imaging.

Lipid-PEG-folate encapsulated nanoparticles with aggregation induced emission characteristics: cellular uptake mechanism and two-photon fluorescence imaging.

Folate functionalized nanoparticles (NPs) that contain fluorogens with aggregation-induced emission (AIE) characteristics are fabricated to show bright far-red/near-infrared fluorescence, a large two-photon absorption cross section and low cytotoxicity, which are internalized into MCF-7 cancer cells mainly through caveolae-mediated endocytosis. One-photon excited in vivo fluorescence imaging illustrates that these AIE NPs can accumulate in a tumor and two-photon excited ex vivo tumor tissue imaging reveals that they can be easily detected in the tumor mass at a depth of 400 µm. These studies indicate that AIE NPs are promising alternatives to conventional TPA probes for biological imaging.

Glycosylated star-shaped conjugated oligomers for targeted two-photon fluorescence imaging.

A glucopyranose functionalized star-shaped oligomer, N-tris{4,4',4''-[(1E)-2-(2-{(E)-2-[4-(benzo[d]thiazol-2-yl)phenyl]vinyl}-9,9-bis(6-2-amido-2-deoxy-1-thio-ß-D-glucopyranose-hexyl)-9H-fluoren-7-yl)vinyl]phenyl}phenylamine (TVFVBN-S-NH(2)), is synthesized for two-photon fluorescence imaging. In water, TVFVBN-S-NH(2) self-assembles into nanoparticles with an average diameter of ∼49 nm and shows a fluorescence quantum yield of 0.21. Two-photon fluorescence measurements reveal that TVFVBN-S-NH(2) has a two-photon absorption cross-section of ∼1100 GM at 780 nm in water. The active amine group on the glucopyranose moiety allows further functionalization of TVFVBN-S-NH(2) with folic acid to yield TVFVBN-S-NH(2) FA with similar optical and physical properties as those for TVFVBN-S-NH(2). Cellular imaging studies reveal that TVFVBN-S-NH(2) FA has increased uptake by MCF-7 cells relative to that for TVFVBN-S-NH(2), due to specific interactions between folic acid and folate receptors on the MCF-7 cell membrane. This study demonstrates the effectiveness of glycosylation as a molecular engineering strategy to yield water-soluble materials with a large two-photon absorption (TPA) cross-section for targeted cancer-cell imaging.

Integration of quantum dots with Zn2GeO4 nanoellipsoids to expand the dynamic detection range of uranyl ions in fluorescent test strips.

Fluorescent colorimetric test strips normally have a narrow dynamic detection-range due to the limited responsive range from single responsive materials, which cannot meet the wide detection requirement in practical applications. Herein, we developed an approach to detect uranyl ions (UO22+) with a broad detection range using the synthesized ZnS:Mn quantum dots (QDs) modified Zn2GeO4 nanoellipsoids (Zn2GeO4 @ZnS:Mn NEs), containing two responsive materials with the opposite signal responses at different UO22+ concentrations. Specifically, a red to chocolate color change was observed at low analyte concentrations (0.01-100 µM) resulting from the photoinduced electron transfer effect from ZnS:Mn QDs to UO22+. A sequentially olive drab to green color change has been observed when further increasing the UO22+ concentration (100-1000 µM) as a result of the antenna effect between Zn2GeO4 nanoellipsoids and UO22+. In addition, a low-cost and portable fluorescent test strip has been further fabricated through embedding Zn2GeO4 @ZnS:Mn NEs on a microporous structure membrane, demonstrating a facile yet effective colorimetric response to UO22+ in lab water, lake water, and seawater with a wide dynamic range. Therefore, it is potentially attractive for real-time and on-site detection of UO22+ in sudden-onset situations.

Antibody Self-Assembly Maximizes Cytoplasmic Immunostaining Accuracy of Compact Quantum Dots.

Antibody conjugates of quantum dots (QDs) are expected to transform immunofluorescence staining by expanding multiplexed analysis and improving target quantification. Recently, a new generation of small QDs coated with multidentate polymers has improved QD labeling density in diverse biospecimens, but new challenges prevent their routine use. In particular, these QDs exhibit nonspecific binding to fixed cell nuclei and their antibody conjugates have random attachment orientations. This report describes four high-efficiency chemical approaches to conjugate antibodies to compact QDs. Methods include click chemistry and self-assembly through polyhistidine coordination, both with and without adaptor proteins that directionally orient antibodies. Specific and nonspecific labeling are independently analyzed after application of diverse blocking agent classes, and a new assay is developed to quantitatively measure intracellular labeling density based on microtubule stain connectivity. Results show that protein conjugation to the QD surface is required to simultaneously eliminate nonspecific binding and maintain antigen specificity. Of the four conjugation schemes, polyhistidine-based coordination of adaptor proteins with antibody self-assembly yields the highest intracellular staining density and the simplest conjugation procedure. Therefore, antibody and adaptor protein orientation, in addition to blocking optimization, are important determinants of labeling outcomes, insights that can inform translational development of these more compact nanomaterials.

3D microscopy and deep learning reveal the heterogeneity of crown-like structure microenvironments in intact adipose tissue.

Crown-like structures (CLSs) are adipose microenvironments of macrophages engulfing adipocytes. Their histological density in visceral adipose tissue (VAT) predicts metabolic disorder progression in obesity and is believed to initiate obesity comorbidities. Here, we use three-dimensional (3D) light sheet microscopy and deep learning to quantify 3D features of VAT CLSs in lean and obese states. Obese CLS densities are significantly higher, composing 3.9% of tissue volume compared with 0.46% in lean tissue. Across the states, individual CLS structural characteristics span similar ranges; however, subpopulations are distinguishable. Obese VAT contains large CLSs absent from lean tissues, located near the tissue center, while lean CLSs have higher volumetric cell densities and prolate shapes. These features are consistent with inefficient adipocyte elimination in obesity that contributes to chronic inflammation, representing histological biomarkers to assess adipose pathogenesis. This tissue processing, imaging, and analysis pipeline can be applied to quantitatively classify 3D microenvironments across diverse tissues.

A reversible dual-response fluorescence switch for the detection of multiple analytes.

This paper reports a reversible dual fluorescence switch for the detection of a proton target and 2,4,6-trinitrotoluene (TNT) with opposite-response results, based on fluorophore derivatization of silica nanoparticles. Fluorescent silica nanoparticles were synthesized through modification of the surface with a nitrobenzoxadiazole (NBD) fluorophore and an organic amine to form a hybrid monolayer of fluorophores and amino ligands; the resultant nanoparticles showed different fluorescence responses to the proton target and TNT. Protonation of the amino ligands leads to fluorescence enhancement due to inhibition of photoinduced electron transfer (PET) between the amine and fluorophore. By contrast, addition of TNT results in fluorescence quenching because a fluorescence resonance energy transfer (FRET) happens between the NBD fluorophore and the formed TNT-amine complex. The fluorescence signal is reversible through washing with the proper solvents and the nanoparticles can be reused after centrifugal separation. Furthermore, these nanoparticles were assembled into chips on an etched silicon wafer for the detection of TNT and the proton target. The assembled chip can be used as a convenient indicator of herbicide (2,4-dichlorophenoxyacetic acid) and TNT residues with the use of only 10 microL of sample. The simple NBD-grafted silica nanoparticles reported here show a reversible signal and good assembly flexibility; thus, they can be applied in multianalyte detection.

Inverted opal fluorescent film chemosensor for the detection of explosive nitroaromatic vapors through fluorescence resonance energy transfer.

This paper reports an inverted opal fluorescence chemosensor for the ultrasensitive detection of explosive nitroaromatic vapors through resonance-energy-transfer-amplified fluorescence quenching. The inverted opal silica film with amino ligands was first fabricated by the acid-base interaction between 3-aminopropyltriethoxysilane and surface sulfonic groups on polystyrene microsphere templates. The fluorescent dye was then chemically anchored onto the interconnected porous surface to form a hybrid monolayer of amino ligands and dye molecules. The amino ligands can efficiently capture vapor molecules of nitroaromatics such as 2,4,6-trinitrotoluene (TNT) through the charge-transfer complexing interaction between electron-rich amino ligands and electron-deficient aromatic rings. Meanwhile, the resultant TNT-amine complexes can strongly suppress the fluorescence emission of the chosen dye by the fluorescent resonance energy transfer (FRET) from the dye donor to the irradiative TNT-amino acceptor through intermolecular polar-polar resonance at spatial proximity. The quenching response of the highly ordered porous films with TNT is greatly amplified by at least 10-fold that of the amorphous silica films, due to the interconnected porous structure and large surface-to-volume ratio. The inverted opal film with a stable fluorescence brightness and strong analyte affinity has lead to an ultrasensitive detection of several ppb of TNT vapor in air.

Bovine Serum Albulmin Protein-Templated Silver Nanocluster (BSA-Ag13 ): An Effective Singlet Oxygen Generator for Photodynamic Cancer Therapy.

This paper reports a novel synthesis approach of bovine serum albumin (BSA) protein-templated ultrasmall (<2 nm) Ag nanocluster (NC) with strong singlet oxygen generation capacity for photodynamic therapy (PDT). An atomically precise BSA-Ag13 NC (i.e., 13 Ag atoms per cluster) is successfully synthesized for the first time by using NaOH-dissolved NaBH4 solution as the controlling reducing agent. The ubiquitous size of BSA-Ag13 NC results in unique behaviors of its photoexcited states as characterized by the ultrafast laser spectroscopy using time-correlated single photon counting and transient absorption techniques. In particular, triply excited states can be largely present in the excited BSA-Ag13 NC and readily sensitized molecular oxygen to produce singlet oxygen (1 O2 ) with a high quantum efficiency (≈1.26 using Rose Bengal as a standard). This value is much higher than its Au analogue (i.e., ≈0.07 for BSA-Au25 NC) and the commonly available photosensitizers. Due to the good cellular uptake and inherent biocompatibility imparted by the surface protein, BSA-Ag13 NC can be applied as an effective PDT agent in generating 1 O2 to kill cancer cell as demonstrated in this study.

Conjugated polymer microparticles for selective cancer cell image-guided photothermal therapy.

Nanotechnology has recently attracted great attention in biomedical research. Current nanoparticle approaches generally require further surface decoration with targeting ligands, peptides or proteins to achieve selective cancer imaging and therapy. This surface functionalization often complicates nanoparticles and leads to protein corona or varied nanoparticle uptake. In this work, we report a facile approach for selective cancer cell image-guided photothermal therapy by fabricating theranostic microparticles (MPs) using conjugated polymers (CPs) as the imaging and therapeutic agents. Through fine tuning of the backbone structures, we synthesized two CPs, poly[9,9-bis(4-(2-ethylhexyl)phenyl)fluorene-alt-co-6,7-bis(4-(hexyloxy)phenyl)-4,9-di(thiophen-2-yl)-thiadiazoloquinoxaline] (PFTTQ) with high near infrared (NIR) molar absorptivity and poly(9,9-dihexylfluorene-alt-2,1,3-benzothiadiazole) (PFBT) with bright green emission. The two CPs were physically blended into single particles with ∼3 µm size, which was confirmed by scanning electron microscopy (SEM) and confocal fluorescence imaging. Although without any surface functionalization, the obtained CP MPs showed selective internalization into MCF-7 cancer cells over NIH-3T3 normal cells, while CP nanoparticles showed similar uptake into both cell lines. Moreover, the CP MPs could selectively kill MCF-7 cells upon NIR irradiation, which showed a half-maximal inhibitory concentration (IC50) of 30 µg mL-1 based on PFTTQ concentration.