In Situ Growth Strategy to Integrate Up-Conversion Nanoparticles with Ultrasmall CuS for Photothermal Theranostics

Ferrocene Derivatives for Photothermal Applications

Ferrocene (Fc) and Fc derivatives have gained popularity in recent years due to their unique structure and characteristics. Among Fc's diverse performances, photothermal conversion, as a primary source of energy conversion, has sparked substantial study attention. This Review summaries Fc and Fc derivatives with photothermal characteristics, as well as their applications developed recently. First, methods for the synthesis of Fc-based materials are systematically discussed. Then, the photothermal conversion mechanism based on nonradiative relaxation is summarized. Furthermore, the most recent advances in Fc-based materials in photothermal applications are described, including photothermal degradation, photothermal antibacterial, photothermal therapies, photothermal catalysis, solar-driven water production, and photothermal CO2 separation. Finally, a summary and insights on the photothermal application of Fc-based materials are provided. This paper seeks to provide researchers with a better knowledge of photothermal behavior while also highlighting the potential of Fc and its derivatives in photothermal fields.

NIR-II light powered hydrogel nanomotor for intravesical instillation with enhanced bladder cancer therapy

Intravesical instillation is the common therapeutic strategy for bladder cancer. Besides chemo drugs, nanoparticles are used as intravesical instillation reagents, offering appealing therapeutic approaches for bladder cancer treatment. Metal oxide nanoparticle based chemodynamic therapy (CDT) converts tumor intracellular hydrogen peroxide to ROS with cancer cell-specific toxicity, which makes it a promising approach for the intravesical instillation of bladder cancer. However, the limited penetration of nanoparticle based therapeutic agents into the mucosa layer of the bladder wall poses a great challenge for the clinical application of CDT in intravesical instillation. Herein, we developed a 1064 nm NIR-II light driven hydrogel nanomotor for the CDT for bladder cancer via intravesical instillation. The hydrogel nanomotor was synthesized via microfluidics, wrapped with a lipid bilayer, and encapsulates CuO2 nanoparticles as a CDT reagent and core-shell structured Fe3O4@Cu9S8 nanoparticles as a fuel reagent with asymmetric distribution in the nanomotor (LipGel-NM). An NIR-II light irradiation of 1064 nm drives the active motion of LipGel-NMs, thus facilitating their distribution in the bladder and deep penetration into the mucosa layer of the bladder wall. After FA-mediated endocytosis in bladder cancer cells, CuO2 is released from LipGel-NMs due to the acidic intracellular environment for CDT. The NIR-II light powered active motion of LipGel-NMs effectively enhances CDT, providing a promising strategy for bladder cancer therapy.

MoOxNWs with mechanical damage - oriented synergistic photothermal / photodynamic therapy for highly effective treating wound infections

Reactive oxygen species (ROS)-based therapy has emerged as a promising antibacterial strategy. However, it faces the limitations of uncontrollable space-time release and excessive lipid peroxidation, which may lead to a series of metabolic disorders and decreased immune function. In this study, mechanical damage by molybdenum oxide nanowires (MoOxNWs) is introduced as a synergistic factor to enhance the photothermal and photodynamic effects for controllable and efficient antibacterial therapy. Through their sharp ends, the nanowires can effectively pierce and damage the bacterial cells, thus facilitating the entry of externally generated ROS into the cells. The ROS are generated via photodynamic effect of the nanowires under a mere 5 min of near-infrared light irradiation. This approach enhances the photothermal (by 27.3 %) and photodynamic properties of ROS generation. MoOxNWs (100 μg·mL-1) achieve sterilisation rates of 97.67 % for extended-spectrum β-lactamase-producing E. coli and 96.34 % for methicillin-resistant Staphylococcus aureus, which are comparable or even exceeding the efficacy of most MoOx-based antibacterial agents. Moreover, they exhibit good biocompatibility and low in vivo toxicity.

Tailoring mSiO2-SmCox nanoplatforms for magnetic/photothermal effect-induced hyperthermia therapy

Hyperthermia therapy is a hotspot because of its minimally invasive treatment process and strong targeting effect. Herein, a synergistic magnetic and photothermal therapeutic nanoplatform is rationally constructed. The well-dispersive mSiO2-SmCox nanoparticles (NPs) were synthesized through a one-step procedure with the regulated theoretical molar ratio of Sm/Co among 1:1, 1:2, and 1:4 for controlling the dispersion and magnetism properties of SmCox NPs in situ growth in the pore structure of mesoporous SiO2 (mSiO2), where mSiO2 with diverse porous structures and high specific surface areas serving for locating the permanent magnetic SmCox NPs. The mSiO2-SmCox (Sm/Co = 1:2) NPs with highly dispersed and uniform morphology has an average diameter of ∼73.08 nm. The photothermal conversion efficiency of mSiO2-SmCox (Sm/Co = 1:2) NPs was determined to be nearly 41%. The further in vitro and in vivo anti-tumor evaluation of mSiO2-SmCox (Sm/Co = 1:2) NPs present promising potentials for hyperthermia-induced tumor therapy due to magnetic and photothermal effects.

Diagnostic efficiency of multi-modal MRI based deep learning with Sobel operator in differentiating benign and malignant breast mass lesions-a retrospective study

Purpose

To compare the diagnostic efficiencies of deep learning single-modal and multi-modal for the classification of benign and malignant breast mass lesions.

Methods

We retrospectively collected data from 203 patients (207 lesions, 101 benign and 106 malignant) with breast tumors who underwent breast magnetic resonance imaging (MRI) before surgery or biopsy between January 2014 and October 2020. Mass segmentation was performed based on the three dimensions-region of interest (3D-ROI) minimum bounding cube at the edge of the lesion. We established single-modal models based on a convolutional neural network (CNN) including T2WI and non-fs T1WI, the dynamic contrast-enhanced (DCE-MRI) first phase was pre-contrast T1WI (d1), and Phases 2, 4, and 6 were post-contrast T1WI (d2, d4, d6); and Multi-modal fusion models with a Sobel operator (four_mods:T2WI, non-fs-T1WI, d1, d2). Training set (n = 145), validation set (n = 22), and test set (n = 40). Five-fold cross validation was performed. Accuracy, sensitivity, specificity, negative predictive value, positive predictive value, and area under the ROC curve (AUC) were used as evaluation indicators. Delong's test compared the diagnostic performance of the multi-modal and single-modal models.

Results

All models showed good performance, and the AUC values were all greater than 0.750. Among the single-modal models, T2WI, non-fs-T1WI, d1, and d2 had specificities of 77.1%, 77.2%, 80.2%, and 78.2%, respectively. d2 had the highest accuracy of 78.5% and showed the best diagnostic performance with an AUC of 0.827. The multi-modal model with the Sobel operator performed better than single-modal models, with an AUC of 0.887, sensitivity of 79.8%, specificity of 86.1%, and positive prediction value of 85.6%. Delong's test showed that the diagnostic performance of the multi-modal fusion models was higher than that of the six single-modal models (T2WI, non-fs-T1WI, d1, d2, d4, d6); the difference was statistically significant (p = 0.043, 0.017, 0.006, 0.017, 0.020, 0.004, all were greater than 0.05).

Conclusions

Multi-modal fusion deep learning models with a Sobel operator had excellent diagnostic value in the classification of breast masses, and further increase the efficiency of diagnosis.

Dumbbell-like upconversion nanoparticles synthesized by controlled epitaxial growth for light-heat-color tri-modal sensing of carcinoembryonic antigen

Accurate quantitative analysis of tumor markers in a wide linear range has important practical significance towards complex clinical samples in cancer identification and monitoring of tumor development stages, but remains challenging. Herein, three-layer dumbbell-like upconversion nanoparticles NaErF₄:Tm@NaYF₄@NaNdF₄ (labeled as UCNPs) combined with G-quadruplex (G₄) DNAzyme are reported for tri-modal sensing of carcinoembryonic antigen (CEA) in a wide range using upconversion luminescence (UCL), photothermal and catalysis signal readouts. Initially, dumbbell-like UCNPs were controlled synthesized by a three-dimensional epitaxial growth strategy through tuning the concentration of Nd precursors. After surface functionalization, G₄zyme-UCNPs-cDNA/Apt-MB was subsequently fabricated by biotin-streptavidin interaction and DNA hybridization. Quantitative detection of CEA was achieved by competitive interaction and magnetic separation, and the intensities of tri-modal signals (light, heat and catalysis-based chrominance) of dissociative probes are linearly related to the concentration of CEA. The results showed that the tri-modal sensing method exhibited a wide linear range (0.005-2000 ng/mL) and low limit of detection (LOD) across three models: the luminescence model (0.005-50 ng/mL, LOD = 0.910 pg/mL), the catalysis model (10-1000 ng/mL, LOD = 0.387 ng/mL), and the temperature model (50-2000 ng/mL, LOD = 1.114 ng/mL). These findings suggest that the tri-modal sensing platform is suitable for use in the analysis of a wide range of complex and diverse clinical samples.

Reduction-responsive dextran-based Pt(IV) nano-prodrug showed a synergistic effect with doxorubicin for effective melanoma treatment

Melanoma, the deadliest skin cancer with high metastasis potential, has posed a great threat to human health. Accordingly, early efficient blocking of melanoma progression is vital in antitumor treatment. Herein, a reduction-responsive dextran-based Pt(IV) nano-prodrug (PDPN) was synthesized and used for doxorubicin (DOX) delivery to combat melanoma synergistically. First, PDPN was prepared by one-pot chemical coupling of carboxylated methoxy poly(ethylene glycol) (mPEG), dextran (Dex), and the crosslinking agent cisPt (IV)-COOH. PDPN had a spherical structure (R_h = 34 ± 11.3 nm). Then, DOX was encapsulated into the PDPN core to form DOX-loaded PDPN (PDPN-DOX). The obtained PDPN-DOX displayed reduction-responsive release of DOX and Pt, thus showing a synergistic anticancer effect in B16F10 cells (combination index, 0.46). Furthermore, in vivo experiments demonstrated that PDPN-DOX was effective for the synergistic treatment of subcutaneous melanoma. Collectively, the as-prepared PDPN could serve as a promising and versatile nano-prodrug carrier for the co-delivery of chemotherapeutics in tumor combination therapy.

Mesoporous nanoplatform integrating photothermal effect and enhanced drug delivery to treat breast cancer bone metastasis

Bone metastatic breast cancer has severely threatened the survival and life quality of patients. Due to the suboptimal efficacy of anti-metastatic chemotherapeutic drugs and the complicated bone marrow microenvironments, effective treatment of metastatic breast cancer remains challenging for traditional clinical approaches. In this work, we developed a mesoporous nanoplatform (m-CuS-PEG) with the co-loading of CuS nanodots and a chemotherapeutic drug cisplatin for the combined photothermal-chemotherapy of bone-metastasized breast cancer. The CuS nanodots were decorated onto mesoporous silica (m-SiO2) surface with dendritic mesoporous channels, into which the cisplatin was accommodated. The carboxyl-terminated poly (ethylene glycol) (PEG) was further functionalized onto the surface to obtain the functional nanoplatform m-CuS-PEG. The drug release of the loaded cisplatin exhibited pH- and thermal-dual responsive manner. The attached CuS nanodots rendered the mesoporous nanoplatform with high photothermal conversion ability. Upon irradiation with a near-infrared laser in the second near-infrared (NIR-II) window, m-CuS-PEG dispersions exhibited rapid temperature elevation and high photostability. The results revealed that m-CuS-PEG had excellent biocompatibility. The cisplatin-loaded m-CuS-PEG not only showed superior cancer cell-killing effects, but also significantly inhibit the growth of metastatic tumors. The tumor-induced bone destruction was also dramatically attenuated by the mesoporous nanoplatform-mediated combined therapy. Overall, the developed functional nanoplatform integrates photothermal therapy and efficient chemotherapeutic drug delivery to offer an alternative approach for combating breast cancer bone metastasis.

Biometric Photoelectrochemical-Visual Multimodal Biosensor Based on 3D Hollow HCdS@Au Nanospheres Coupled with Target-Induced Ion Exchange Reaction for Antigen Detection

Three-dimensional (3D) hollow photoactive nanomaterials can enhance light capture due to the light scattering benefiting from the unique hollow nanostructures, which contributes to the decrease in energy loss and the electron-hole recombination during the process of photoelectric conversion. Herein, a 3D hollow HCdS@Au nanosphere synthesized by the templated-assisted method and photodeposition is employed to construct a multimodal sensing platform by combining the photoelectrochemical (PEC) biosensor with colorimetric analysis and photothermal imaging. In the presence of target carcinoembryonic antigen (CEA), a sandwich structure is formed on magnetic beads based on the dual-aptamer recognition, followed by the initiation of rolling circle amplification (RCA) to bind numerous CuO-DNA probes. Upon stimulation by chlorhydric acidic, a large number of Cu²⁺ is released from CuO, which could interact with yellow HCdS@Au on electrode to produce dark CuS by ion exchange. As a result, with increased CEA level, the photocurrent is weakened and the color of electrode interface is changed from yellow to dark, which thus facilitates the PEC and colorimetric detection of CEA. Simultaneously, the formed CuS with highly photothermal effect can achieve qualitative visual analysis of CEA using a portable infrared thermal imager. This work exhibits an excellent performance for sensitive and selective detection of CEA in the dynamic working range from 0.015 to 2.4 ng/mL with a detection limit as low as 3.5 pg/mL. Moreover, the proposed PEC biosensor is successfully applied to CEA determination in human serum, which holds great promise in accurate analysis of biomarkers and early diagnosis of diseases in the clinic.

Rational assembly of RGD/MoS2/Doxorubicin nanodrug for targeted drug delivery, GSH-stimulus release and chemo-photothermal synergistic antitumor activity

Herein, we present the facile design and construction of a nanodrug system integrating targeted drug delivery and synergistic chemo-photothermal antitumor activity. MoS₂ nanosheets were synthesized and modified by α_νβ₃ integrin binding peptide (Arg-Gly-Asp, RGD) using lipoic acid functionalized polyethylene glycol (LA-PEG-COOH), forming a well dispersed and targeted delivery nanocarrier. Further, covalent coupling of antitumor drug, thiolated doxorubicin (DOX) via disulfide linkage resulted in a novel nanodrug, RGD/MoS₂/DOX. The prepared nanocarrier showed favorable stability, biocompatibility and photothermal conversion efficiency. Fluorescence imaging revealed that Hela cells could endocytose far more nanodrug than H9c2 normal myocardial cells due to the targeted delivery characteristic. Particularly, GSH-induced disulfide bond cleavage facilitated the effective release of DOX from the nanodrug in the tumor microenvironment. The survival rate of Hela cells incubated with the nanodrug for 48 h was 22.2 ± 1.2%, which dramatically reduced to 8.9 ± 1.4% in combination with 808 nm NIR irradiation, demonstrating powerful photothermal induced tumor-killing efficacy. In contrast, the survival rates of H9c2 cells treated by the nanodrug and free DOX were 68.5 ± 2.6% and 6.7 ± 2.6%, respectively, an indication of the notably alleviated cardiotoxicity of the designed nanodrug. The cell apoptosis experiment further verified the synergistic chemo-photothermal effect, thus paving a way toward design of high-efficiency and low-toxicity antitumor nanodrug.

Nanocomposites based on lanthanide-doped upconversion nanoparticles: diverse designs and applications

Lanthanide-doped upconversion nanoparticles (UCNPs) have aroused extraordinary interest due to the unique physical and chemical properties. Combining UCNPs with other functional materials to construct nanocomposites and achieve synergistic effect abound recently, and the resulting nanocomposites have shown great potentials in various fields based on the specific design and components. This review presents a summary of diverse designs and synthesis strategies of UCNPs-based nanocomposites, including self-assembly, in-situ growth and epitaxial growth, as well as the emerging applications in bioimaging, cancer treatments, anti-counterfeiting, and photocatalytic fields. We then discuss the challenges, opportunities, and development tendency for developing UCNPs-based nanocomposites.

Enhanced Eradication of Enterococcus faecalis Biofilms by Quaternized Chitosan-Coated Upconversion Nanoparticles for Photodynamic Therapy in Persistent Endodontic Infections

Due to the persistent presence of Enterococcus faecalis biofilms in apical root canals, persistent endodontic infections (PEIs) have always been an intractable disease to solve. The conventional root canal disinfectants (e.g., calcium hydroxide, chlorhexidine) are arduous to scavenge the stubborn infection. With the progress of nanomedicine in the biomedical field, antimicrobial photodynamic therapy (aPDT) is emerging as a prospective anti-infective therapy for PEIs. Herein, quaternized chitosan (QCh) modified upconversion nanoparticles (UCNP)@SiO₂/methylene blue (MB) are developed with enhanced antibacterial/biofilm performance for aPDT in PEIs. QCh is coated on the UCNP@SiO₂/MB by testing the changes in diameter, chemical functional group, and charge. Interestingly, QCh also increases the conversion efficiency of UCNP to generate more reactive oxygen species (ROS). Furthermore, the prepared UCNP@SiO₂/MB@QCh exhibits highly effective antibacterial activity against free E. faecalis and related biofilm in vitro and extracted teeth. Importantly, the additional QCh with positive charges enhance UCNP@SiO₂/MB@QCh contact with E. faecalis (negative charges) through electrostatic interaction. Then, UCNP@SiO₂/MB@QCh could stick close to the E. faecalis and generate ROS under the irradiation by a 980 nm laser. The in vitro cellular test shows that UCNP@SiO₂/MB@QCh has acceptable cytocompatibility. Thus, UCNP@SiO₂/MB@QCh could offer a novel strategy for the potential aPDT clinical applications in the treatment of PEIs.

γ-Fe2 O3 Loading Mitoxantrone and Glucose Oxidase for pH-Responsive Chemo/Chemodynamic/Photothermal Synergistic Cancer Therapy

Traditional cancer therapy is limited by poor prognosis and risk of recurrence. Emerging therapies offer alternatives to these problems. In addition, synergistic therapy can combine the advantages of multiple therapies to eliminate cancer cells while attenuating damage to normal tissues. Herein, a theranostic nanoplatform based on the chemotherapeutic drug mitoxantrone (MTO) and glucose oxidase (GOx) co-loaded γ-Fe₂ O₃ nanoparticles (MTO-GOx@γ-Fe₂ O₃ NPs) is designed and prepared to realize photoacoustic imaging-guided chemo/chemodynamic/photothermal (CT/CDT/PTT) synergistic cancer therapy. With a particle size of about 86.2 nm, the synthesized MTO-GOx@γ-Fe₂ O₃ NPs can selectively accumulate at tumor sites by enhanced permeability and retention (EPR) effects. After entering cancer cells by endocytosis, MTO-GOx@γ-Fe₂ O₃ NPs decompose into Fe³⁺ ions and release cargo because of their pH-responsive characteristic. As a Food and Drug Administration (FDA)-approved chemotherapy drug, MTO shows strong DNA disruption ability and satisfying photothermal conversion ability under laser irradiation for photothermal therapy. Simultaneously, GOx catalyzes the decomposition of glucose and generates hydrogen peroxide (H₂ O₂ ) to enhance the chemodynamic therapy efficiency. In vitro and in vivo experiments reveal that MTO-GOx@γ-Fe₂ O₃ NPs possess a significant synergistic therapeutic effect in cancer treatment.

NIR-regulated dual-functional silica nanoplatform for infected-wound therapy via synergistic sterilization and anti-oxidation

Nature-derived bioactive components and photothermal synergistic therapy bring potential strategies for fighting bacterial infection and accelerating would healing by virtue of their excellent therapeutic efficiencies and ignorable side effects, where photothermal property not only acts as sterilization energy but also as a doorkeeper to control the natural component release. Herein, by integrating the excellent antibacterial property of cinnamaldehyde (CA) and the outstanding photothermal performance of copper sulfide nanoparticles (CuS NPs), a multifunctional nanoplatform of SiO₂ @CA@CuS nanospheres (NSs) is constructed with silica nanosphere (SiO₂ NSs) as carrier. SiO₂ @CA@CuS NSs exhibit photothermal property, bacterial absorption capacity, extraordinary antibacterial activity and antioxidant property. Mechanism characteriazation and antibacterial experiment indicate that positive charged SiO₂ @CA@CuS can adhere to the negative charged surface of bacteria, and quickly kill bacteria through the synergistic action of the released CA and heat produced under near infrared light (NIR) irradiation at 980 nm. The sterilization efficiencies for Escherichia coli (E. coli) and S. aureus reach 99.86% and 99.84%, respectively. Furthermore, NIR-regulated SiO₂ @CA@CuS perform great biocompatibility, as well as effective effects for accelerating S. aureus-infected wound healing at a low photothermal temperature (45 °C) relying on synergistic sterilization and anti-oxidation.

In Situ Fabrication of Nanoprobes for 19F Magnetic Resonance and Photoacoustic Imaging-Guided Tumor Therapy

It is challenging to fabricate multimodal imaging nanoprobes with high penetration depth and long blood circulation. Herein, we present multifunctional fluorinated nanoprobes (CFPP NPs) containing in situ formed copper chalcogenide nanoparticles for ¹⁹F magnetic resonance imaging (MRI) and photoacoustic imaging (PAI). The formed hydrophilic copper chalcogenide nanoassemblies demonstrated easy excretion stemming from facile disassembly, enhanced photothermal ability, and novel localized surface plasmon resonance (LSPR) absorption (centered at 1064 nm) in the "biological transparent" region. Both ¹⁹F MRI and PAI render these CFPP NPs suitable for multimodal imaging with high penetration depth and low background. Moreover, the chemo-photothermal synergistic therapy results suggest great potential in multimodal nanoprobes for imaging-guided tumor therapy applications.

Predicting HER2 Status in Breast Cancer on Ultrasound Images Using Deep Learning Method

Purpose

The expression of human epidermal growth factor receptor 2 (HER2) in breast cancer is critical in the treatment with targeted therapy. A 3-block-DenseNet-based deep learning model was developed to predict the expression of HER2 in breast cancer by ultrasound images.

Methods

The data from 144 breast cancer patients with preoperative ultrasound images and clinical information were retrospectively collected from the Shandong Province Tumor Hospital. An end-to-end 3-block-DenseNet deep learning classifier was built to predict the expression of human epidermal growth factor receptor 2 by ultrasound images. The patients were randomly divided into a training (n = 108) and a validation set (n = 36).

Results

Our proposed deep learning model achieved an encouraging predictive performance in the training set (accuracy = 85.79%, AUC = 0.87) and the validation set (accuracy = 80.56%, AUC = 0.84). The effectiveness of our model significantly exceeded the clinical model and the radiomics model. The score of the proposed model showed significant differences between HER2-positive and -negative expression (p < 0.001).

Conclusions

These results demonstrate that ultrasound images are predictive of HER2 expression through a deep learning classifier. Our method provides a non-invasive, simple, and feasible method for the prediction of HER2 expression without the manual delineation of the regions of interest (ROI). The performance of our deep learning model significantly exceeded the traditional texture analysis based on the radiomics model.

Decreasing hyaluronic acid combined with drug-loaded nanoprobes improve the delivery and efficacy of chemotherapeutic drugs for pancreatic cancer

Pancreatic cancer is one of the common malignant tumors of the digestive system, and its clinical treatment is still very challenging. Most of the pancreatic cancer chemotherapeutic drugs have poor plasma stability, low cell uptake efficiency, and are prone to developing drug resistance and toxic side effects. Besides, pancreatic cancer often has a dense extracellular matrix, which consists of collagens, hyaluronic acid, and other proteoglycans. Among them, hyaluronic acid is a key component of the dense matrix, which results in vascular compression and insufficient perfusion, and hinders the delivery of chemotherapeutic drugs. In this study, we explore using hyaluronidase in tumor-bearing mice to eliminate the hyaluronic acid barrier, to reduce blood vessel compression and reshape the tumor microenvironment. In addition, we evaluate using doxorubicin-loaded nanoprobes to improve the stability and local tumor-killing effect of the drug. The nanoprobes have the characteristics of near-infrared optical imaging, which are used to monitor the tumor size in real-time during the treatment process, and dynamically observe the tumor inhibitory effect. The results show that elimination of the hyaluronic acid barrier combined with the doxorubicin-loaded nanoprobes can greatly increase drug penetration into tumor tissue and improve the effectiveness of chemotherapy drugs. This study provides a novel strategy for the treatment of pancreatic cancer.

Upconversion, MRI imaging and optical trapping studies of silver nanoparticle decorated multifunctional NaGdF4:Yb,Er nanocomposite

The multifunctional upconversion nanoparticles (UCNPs) are fascinating tool for biological applications. In the present work, photon upconverting NaGdF₄:Yb,Er and Ag nanoparticles decorated NaGdF₄:Yb,Er (NaGdF₄:Yb,Er@Ag) nanoparticles were prepared using a simple polyol process. Rietveld refinement was performed for detailed crystal structural and phase fraction analysis. The morphology of the NaGdF₄:Yb,Er@Ag was examined using high-resolution transmission electron microscope, which reveals silver nanoparticles of 8 nm in size were decorated over spherical shaped NaGdF₄:Yb,Er nanoparticles with a mean particle size of 90 nm. The chemical compositions were confirmed by EDAX and inductively coupled plasma-optical emission spectrometry analyses. The upconversion luminescence (UCL) of NaGdF₄:Yb,Er at 980 nm excitation showed an intense red emission. After incorporating the silver nanoparticles, the UCL intensity decreased due to weak scattering and surface plasmon resonance effect. The VSM magnetic measurement indicates both the UCNPs possess paramagnetic behaviour. The NaGdF₄:Yb,Er@Ag showed computed tomography imaging. Magnetic resonance imaging study exhibited better T1 weighted relaxivity in the NaGdF₄:Yb,Er than the commercial Gd-DOTA. For the first time, the optical trapping was successfully demonstrated for the upconversion NaGdF₄:Yb,Er nanoparticle at near-infrared 980 nm light using an optical tweezer setup. The optically trapped UCNP possessing paramagnetic property exhibited a good optical trapping stiffness. The UCL of trapped single UCNP is recorded to explore the effect of the silver nanoparticles. The multifunctional properties for the NaGdF₄:Yb,Er@Ag nanoparticle are demonstrated.

A H2S-Triggered Dual-Modal Second Near-Infrared/Photoacoustic Intelligent Nanoprobe for Highly Specific Imaging of Colorectal Cancer

An endogenous H₂S-triggered intelligent optical nanoprobe combining second near-infrared (NIR-II) fluorescence with photoacoustic (PA) imaging can provide more comprehensive information to further improve the sensitivity and reliability of diagnosis for colorectal tumor, which is rarely explored. Herein, an endogenous H₂S-triggered SiO₂@Ag nanoprobe was designed for in situ dual-modal NIR-II/PA imaging of colorectal cancer. The designed dual-modal nanoprobe can be converted to SiO₂@Ag₂S after in situ biosynthesis via a sulfuration reaction with the over-expressed endogenous H₂S in the colorectal tumor. More importantly, the designed SiO₂@Ag nanoprobe exhibits high sensitivity and specificity for diagnosing colorectal cancer in vivo via dual-modal NIR-II/PA imaging. These results provide a new NIR-II/PA dual-modal imaging strategy for noninvasive intelligent detection of colorectal cancer.

Structures, plasmon-enhanced luminescence, and applications of heterostructure phosphors

Heterostructure phosphor composites have been used widely in the fields of targeted bio-probes and bio-imaging, hyperthermia treatment, photocatalysis, solar cells, and fingerprint identification. The structures, plasmon-enhanced luminescence and mechanism of metal/fluorophore heterostructure composites, such as core-shell nanocrystals, multilayers, adhesion, islands, arrays, and composite optical glass, are reviewed in detail. Their extended applications were explored widely since the surface plasmon resonance effect increased the up-conversion efficiency of fluorophores significantly. We summarize their synthesis methods, size and shape control, absorption and excitation spectra, plasmon-enhanced up-conversion luminescence, and specific applications. The most important results acquired in each case are summarized, and the main challenges that need to be overcome are discussed.

NIR II Luminescence Imaging for Sentinel Lymph Node and Enhanced Chemo-/Photothermal Therapy for Breast Cancer

In this research, a NIR II luminescence imaging and enhanced chemo-/photothermal therapy system of CuS-DOX-Nd/FA NPs for breast cancer and lymph node tracing under single 808 nm irradiation is proposed. Nd-DTPA molecular cluster with the NIR II imaging effect as the carrier was designed to load the ultrasmall CuS nanoparticles and chemotherapeutic drug doxorubicin hydrochloride (DOX). The composite probe is used for tumor lesion imaging and tracking the breast cancer sentinel lymph nodes with simultaneous chemo-/photothermal therapy (PTT) for breast cancer under the single 808 nm laser. This designed probe not only has high permeability and retention (EPR) targeting effect but also can respond to the tumor microenvironment (TME), realizing more precise and efficient release of DOX at the cancer focus. At the same time, CuS as a drug carrier has a good photothermal therapy effect (photothermal conversion efficiency: 27.9%). The serialized released chemotherapy DOX and synergistic PTT effect can be used to the treat the in situ breast cancer land and simultaneously kill the metastasis cancer. The system made the combined molecular clusters Nd-DTPA achieve NIR II imaging of tumor lesions of breast cancer and lymph node to obtain the integration of diagnosis of the transferred disease for better prognosis. The feasibility of the system had obvious tumor growth inhibition effect with NIR II imaging guided is verified by a series of in vitro and in vivo experiments.

A Dual-Responsive Platform Based on Antifouling Dendrimer-CuS Nanohybrids for Enhanced Tumor Delivery and Combination Therapy

Design of stimuli-responsive nanomedicine with enhanced tumor delivery for combination therapy still remains a great challenge. Here, a unique design of an antifouling-dendrimer-based nanoplatform with dual pH- and redox-responsiveness is reported to meet this challenge. First, generation 5 (G5) poly(amidoamine) dendrimers are modified with targeting ligand cyclic arginine-glycine-aspartic acid (RGD) peptide through a polyethylene glycol (PEG) spacer and zwitterion of thiolated N,N-dimethyl-cysteamine-carboxybetaine (CBT) via pH-responsive benzoicimine bond to form G5.NH₂ PEGRGDCBT conjugates. Then, doxorubicin (DOX) is linked to the functional G5 dendrimers through a redox-responsive disulfide bond, followed by entrapment of CuS nanoparticles within the dendrimers. The created functional dendrimer-CuS nanohybrids with a CuS core size of 3.6 nm display a good antifouling property and excellent photothermal conversion property in the second near-infrared window. In addition, the neutral surface charge of the nanohybrids is able to be switched to be positive in the tumor region with slightly acidic microenvironment due to the break of benzoicimine bond to promote their intracellular uptake, while the redox-sensitive disulfide bond affords the fast release of the conjugated DOX within tumor cells to exert its therapeutic effect. Taken together with the CuS cores, the created dendrimer-CuS nanohybrids enable enhanced combination chemotherapy and photothermal therapy of tumors.

Phenolic-enabled nanotechnology: versatile particle engineering for biomedicine

Phenolics are ubiquitous in nature and have gained immense research attention because of their unique physiochemical properties and widespread industrial use. In recent decades, their accessibility, versatile reactivity, and relative biocompatibility have catalysed research in phenolic-enabled nanotechnology (PEN) particularly for biomedical applications which have been a major benefactor of this emergence, as largely demonstrated by polydopamine and polyphenols. Therefore, it is imperative to overveiw the fundamental mechanisms and synthetic strategies of PEN for state-of-the-art biomedical applications and provide a timely and comprehensive summary. In this review, we will focus on the principles and strategies involved in PEN and summarize the use of the PEN synthetic toolkit for particle engineering and the bottom-up synthesis of nanohybrid materials. Specifically, we will discuss the attractive forces between phenolics and complementary structural motifs in confined particle systems to synthesize high-quality products with controllable size, shape, composition, as well as surface chemistry and function. Additionally, phenolic's numerous applications in biosensing, bioimaging, and disease treatment will be highlighted. This review aims to provide guidelines for new scientists in the field and serve as an up-to-date compilation of what has been achieved in this area, while offering expert perspectives on PEN's use in translational research.

Targeted Luminescent Probes for Precise Upconversion/NIR II Luminescence Diagnosis of Lung Adenocarcinoma

In this research, the antibody of the searched hub genes has been proposed to combine with a rare-earth composite for an upconversion luminescence (UCL) and downconversion (DCL) NIR-II imaging strategy for the diagnosis of lung adenocarcinoma (LUAD). Weighted gene co-expression network analysis is used to search the most relevant hub genes, and the required top genes that contribute to tumorigenesis (negative: CLEC3B, MFAP4, PECAM1, and FHL1; positive: CCNB2, CDCA5, HMMR, and TOP2A) are identified and validated by survival analysis and transcriptional and translational results. Meanwhile, fluorescence imaging probes (NaYF₄:Yb,Er,Eu@NaYF₄:Nd, denoted as NYF:Eu NPs) with multimodal optical imaging properties of downconversion and upconversion luminescence in the visible region and luminescence in the near infrared II region are designed with various uniform sizes and enhanced penetration and sensitivity. Finally, when the NYF:Eu NP probe is combined with antibodies of these chosen positive hub genes (such as, TOP2A and CCNB2), the in vitro and in vivo animal experiments (flow cytometry, cell counting kit-8 assay using A549 cells, and in vivo immunohistochemistry IHC microscopy images of LUAD from patient cases) indicate that the designed nanoprobes can be excellently used as a targeted optical probe for future accurate diagnosis and surgery navigation of LUAD in contrast with other cancer cells and normal cells. This strategy of antibodies combined with optical probes provides a dual-modal luminescence imaging method for precise medicine.

A novel theranostic nanoplatform for imaging-guided chemo-photothermal therapy in oral squamous cell carcinoma

Oral squamous cell carcinoma (OSCC) is highly malignant and invasive, and current treatments are limited due to serious side effects and unsatisfactory outcomes. Here, we reported the terbium ion-doped hydroxyapatite (HATb) nanoparticle as a luminescent probe to encapsulate both the near-infrared (NIR) photothermal agent polydopamine (PDA) and anticancer doxorubicin (DOX) for imaging-guided chemo-photothermal therapy. The morphology, crystal structure, fluorescence, and composition of HATb-PDA-DOX were characterized. HATb-PDA showed a high DOX loading capacity. A theranostic nanoplatform showed pH/NIR responsive release properties and better antitumor outcomes in OSCC cells than monomodal chemotherapy or photothermal therapy, while keeping side effects at a minimum. Also, the luminescence signal was confirmed to be tracked and the increase of the red/green (R/G) ratio caused by the DOX release could be used to monitor the DOX release content. Furthermore, HATb-PDA-DOX plus NIR treatment synergistically promoted in vitro cell death through the overproduction of reactive oxygen species (ROS), cell cycle arrest, and increased cell apoptosis. Overall, this work presents an innovative strategy in designing a multifunctional nano-system for imaging-guided cancer treatment.

Synthesis and molecular dynamics simulation of CuS@GO–CS hydrogel for enhanced photothermal antibacterial effect

CuS@GO–CS hydrogels were prepared by a simple method and possessed an enhanced photothermal antibacterial effect against E. coli and S. aureus.

Integration of IR-808 and thiol-capped Au–Bi bimetallic nanoparticles for NIR light mediated photothermal/photodynamic therapy and imaging

A novel Au–Bi bimetallic nanoplatform has been developed for enhanced photodynamic and photothermal therapy.

One-pot synthesis of dumbbell shaped PbS–Te hybrids with promising photothermal properties

The development of multi-component photothermal agents has attracted increasing attention due to their potential applications in energy conversion, medical treatments, etc. Herein, a dumbbell shaped PbS–Te heterostructure was prepared via a one-pot microwave-assisted decomposition of lead dimethyl dithiocarbamate and tellurium diethyl dithiocarbamate. The as-obtained PbS–Te hybrids exhibit excellent photothermal stability and strong optical absorption over a broad wavelength range spanning from ultraviolet to near-infrared, where the photothermal conversion efficiency could reach as high as 12.1%. Such promising photothermal performance demonstrates the advantages of one-pot synthesis that results in more intimate contacts among individual components.

The Coppery Age: Copper (Cu)-Involved Nanotheranostics

As an essential trace element in the human body, transitional metal copper (Cu) ions are the bioactive components within the body featuring dedicated biological effects such as promoting angiogenesis and influencing lipid/glucose metabolism. The recent substantial advances of nanotechnology and nanomedicine promote the emerging of distinctive Cu-involved biomaterial nanoplatforms with intriguing theranostic performances in biomedicine, which are originated from the biological effects of Cu species and the physiochemical attributes of Cu-composed nanoparticles. Based on the very-recent significant progresses of Cu-involved nanotheranostics, this work highlights and discusses the principles, progresses, and prospects on the elaborate design and rational construction of Cu-composed functional nanoplatforms for a diverse array of biomedical applications, including photonic nanomedicine, catalytic nanotherapeutics, antibacteria, accelerated tissue regeneration, and bioimaging. The engineering of Cu-based nanocomposites for synergistic nanotherapeutics is also exemplified, followed by revealing their intrinsic biological effects and biosafety for revolutionizing their clinical translation. Finally, the underlying critical concerns, unresolved hurdles, and future prospects on their clinical uses are analyzed and an outlook is provided. By entering the "Copper Age," these Cu-involved nanotherapeutic modalities are expected to find more broad biomedical applications in preclinical and clinical phases, despite the current research and developments still being in infancy.

Biomineralization: An Opportunity and Challenge of Nanoparticle Drug Delivery Systems for Cancer Therapy

Biomineralization is a common process in organisms to produce hard biomaterials by combining inorganic ions with biomacromolecules. Multifunctional nanoplatforms are developed based on the mechanism of biomineralization in many biomedical applications. In the past few years, biomineralization-based nanoparticle drug delivery systems for the cancer treatment have gained a lot of research attention due to the advantages including simple preparation, good biocompatibility, degradability, easy modification, versatility, and targeting. In this review, the research trends of biomineralization-based nanoparticle drug delivery systems and their applications in cancer therapy are summarized. This work aims to promote future researches on cancer therapy based on biomineralization. Rational design of nanoparticle drug delivery systems can overcome the bottleneck in the clinical transformation of nanomaterials. At the same time, biomineralization has also provided new research ideas for cancer treatment, i.e., targeted therapy, which has significantly better performance.

Selective Decoating-Induced Activation of Supramolecularly Coated Toxic Nanoparticles for Multiple Applications

In spite of the rapid emergence of numerous nanoparticles (NPs) for biomedical applications, it is often challenging to precisely control, or effectively tame, the bioactivity/toxicity of NPs, thereby exhibiting limited applications in biomedical areas. Herein, we report the construction of hyaluronic acid (HA)-laminated, otherwise toxic methylviologen (MV), NPs via ternary host-guest complexation among cucurbit[8]uril, trans-azobenzene-conjugated HA, and MV-functionalized polylactic acid NPs (MV-NPs). The high, nonspecific toxicity of MV-NPs was effectively shielded (turned off) by HA lamination, as demonstrated in cells, zebrafish, and mouse models. The supramolecular host-guest interaction-mediated HA coating offered several HA-MV-NP modalities, including hyaluronidase locally and photoirradiation remotely, to precisely remove HA lamination on demand, thereby endowing materials with the capability of selective decoating-induced activation (DIA) for applications as a user-friendly herbicide, a selective antibacterial agent, or an anticancer nanomedicine. This work offers facile supramolecular coating and DIA strategies to effectively tame and precisely control the bioactivity and toxicity of functional nanomaterials for diverse applications.

Optimized Multimetal Sensitized Phosphor for Enhanced Red Up-Conversion Luminescence by Machine Learning

In this research, machine learning including the genetic algorithm (GA) and support vector machine (SVM) algorithm is used to solve the "low up-conversion luminescence (UCL) intensity" problem in order to find the optimal phosphor with enhanced red UCL emission using multielement K/Li/Mn metal modulation. Compared with the first generation of phosphors, the best phosphors' fluorescence intensity occurs in the third generation optimized by the GA, with a stronger brightness (4.91-fold), a higher relative quantum yield (6.40-fold), and an enhanced tissue penetration depth (by 5 mm). The single and multiple dopants effect on the upconversion intensity of K+Li+Mn sensitizers is also studied: the intensity increases first and then decreases with the increase of Yb/Er/K+Li+Mn content, and the optimized K+Li+Mn concentration is 6.03%. In order to confirm the stability of the brightness optimization by the GA, a batch of phosphors was synthesized with the same element proportion, and the similarity of fluorescence intensity of two batches of phosphors was evaluated by the SVM algorithm with the classification accuracy index. Finally, the optimized phosphor was used for bioimaging and phosphor-LED.

Microplasmas for Advanced Materials and Devices

Microplasmas are low-temperature plasmas that feature microscale dimensions and a unique high-energy-density and a nonequilibrium reactive environment, which makes them promising for the fabrication of advanced nanomaterials and devices for diverse applications. Here, recent microplasma applications are examined, spanning from high-throughput, printing-technology-compatible synthesis of nanocrystalline particles of common materials types, to water purification and optoelectronic devices. Microplasmas combined with gaseous and/or liquid media at low temperatures and atmospheric pressure open new ways to form advanced functional materials and devices. Specific examples include gas-phase, substrate-free, plasma-liquid, and surface-supported synthesis of metallic, semiconducting, metal oxide, and carbon-based nanomaterials. Representative applications of microplasmas of particular importance to materials science and technology include light sources for multipurpose, efficient VUV/UV light sources for photochemical materials processing and spectroscopic materials analysis, surface disinfection, water purification, active electromagnetic devices based on artificial microplasma optical materials, and other devices and systems including the plasma transistor. The current limitations and future opportunities for microplasma applications in materials related fields are highlighted.

Lanthanide-Based Nanocomposites for Photothermal Therapy under Near-Infrared Laser: Relationship between Light and Heat, Biostability, and Reaction Temperature

In this research, typical organic/inorganic photothermal therapy (PTT) agents were designed with a combination of upconversion luminescent (UCL) or near-infrared (NIR) II imaging rare-earth nanomaterials for photo-acoustic (PA)/UCL/NIR II imaging-guided PTT under NIR laser irradiation. The results show the following: (1) The PTT effect mainly comes from NIR absorption and partly from UCL light conversion. (2) Visible UCL emission is mainly quenched by NIR absorption of the coated PTT agent and partly quenched by visible absorption, indicating that excitation may play a more important role than in the UCL emission process. (3) The biostability of the composite might be decided by the synthesis reaction temperature. Among the five inorganic/organic nanocomposites, UCNP@MnO₂ is the most suitable candidate for cancer diagnosis and treatment because of its stimuli-response ability to the micro-acid environment of tumor cells and highest biostability. The composites generate heat for PTT after entering the tumor cells, and then, the visible light emission gradually regains as MnO₂ is reduced to colorless Mn²⁺ ions, thereby illuminating the cancer cells after the therapy.

Colorless Silk/Copper Sulfide Hybrid Fiber and Fabric with Spontaneous Heating Property under Sunlight

With the increasing demand for comfort, thinness, and warmth of fabrics, various functional fibers have emerged. However, natural silkworm silk, as one of the most widely used natural fibers in textile, faces the issue that it cannot be modified during the spinning process like synthetic fibers. Herein, copper sulfide nanoparticles (CuS NPs) with a near-infrared (NIR) absorption property were first prepared by using regenerated silk fibroin (RSF) as the biological template. Then, trace CuS NPs prepared in RSF solution (no more than 100 ppm) were added into the RSF spinning dope to prepare colorless RSF/CuS hybrid fibers via wet-spinning process. The tensile test of the RSF/CuS hybrid fibers showed that the toughness was improved with the addition of CuS NPs, which completely met the requirements of textile development. The temperature of RSF/CuS hybrid fiber bundles could increase 18.5 °C within 3 min under 1064 nm laser irradiation with power density of 1.0 W/cm². Finally, these RSF/CuS hybrid fiber bundles were woven into silk fabric or embroidered on a cotton fabric. Under the simulated sunlight, the temperature of RSF/CuS fabric could increase to more than 40 °C from room temperature. Also, as per the infrared images, the pattern of embroidery displayed a significant difference in temperature increase as compared to cotton matrix. Based on these results, an almost colorless RSF/CuS hybrid fiber that can be mass produced by wet spinning may have great potential in the fabrication of dyeable, light, and comfortable silk functional fabric with spontaneous heating characteristics under sunlight.

Decoration of upconversion nanocrystals with metal sulfide quantum dots by a universal in situ controlled growth strategy

Conjugating transition-metal sulfide quantum dots and upconversion nanocrystals (UCNCs) has aroused widespread concern due to enhanced physical and chemical properties in contrast to only their simple sum. However, the synthesis of such hybrid nanoparticles by a universal in situ growth strategy has been scarcely reported so far. Herein, we developed a facile approach to functionalize NaYF₄:Yb/Er with chitosan (NaYF₄:Yb/Er@CS), which not only could improve the hydrophilicity of NaYF₄:Yb/Er, but also can form stable chelates with transition-metal ions. Then, ultrasmall metal sulfide (Mⁿ⁺S, M = Ag, Cu, Cd) quantum dots (QDs) can be conjugated homogeneously on the surface of NaYF₄:Yb/Er@CS. Taking Ag₂S as an example, the growth behavior of Ag₂S QDs on the surface of NaYF₄:Yb/Er@CS was studied specifically. The influence of the Ag : Y ratio, S : Ag ratio, pH value, reaction time and reaction temperature on the growth behavior of Ag₂S on the surface of NaYF₄:Yb/Er@CS was investigated systematically. Meanwhile, this innovative strategy is also suitable for the growth of ultrasmall QDs in various shapes, including plates, spheres and rods. The resultant NaYF₄:Yb/Er@CS@Ag₂S system possesses both upconversion luminescence (UCL) properties of NaYF₄:Yb/Er and a good photothermal conversion effect of Ag₂S, and is a promising candidate for UCL imaging guided PTT of cancer.

An optimized lanthanide-chlorophyll nanocomposite for dual-modal imaging-guided surgery navigation and anti-cancer theranostics

A lanthanide-chlorophyll nanocomposite with enhanced red emission under a near-infrared laser was designed for dual-modal imaging-guided surgery navigation and anti-cancer theranostics.

Polydopamine Nanoparticles for Deep Brain Ablation via Near-Infrared Irradiation

Local resection or ablation remains an important approach to treat drug-resistant central neurological disease. Conventional surgical approaches are designed to resect the diseased tissues. The emergence of photothermal therapy (PTT) offers a minimally invasive alternative. However, their poor penetration and potential off-target effect limit their clinical application. Here, polydopamine nanoparticles (PDA-NPs) were prepared and characterized. Studies were performed to evaluate whether PDA-NPs combined with near-infrared (NIR) light can be used to ablate deep brain structures in vitro and in vivo. PDA-NPs were prepared with a mean diameter of ∼150 nm. The particles show excellent photothermal conversion efficiency. PDA-NPs did not show remarkable cytotoxicity against neuronal-like SH-SY5Y cell lines. However, it can cause significant cell death when combined with NIR irradiation. Transcranial NIR irradiation after PDA-NPs administration induced enhanced local hyperthermia as compared with NIR alone. Local temperature exceeded 60 °C after 6 min of irradiation plus PDA while it can only reach 48 °C with NIR alone. PTT with PDA (10 mg/mL, 3 μL) and NIR (1.5 W/cm²) can ablate deep brain structures precisely with an ablation volume of ∼6.5 mm³. Histological analysis confirmed necrosis and apoptosis in the targeted area. These results demonstrate the potential of NP-assisted PTT for the treatment against nontumorous central neurological diseases.

Prussian blue-coated lanthanide-doped core/shell/shell nanocrystals for NIR-II image-guided photothermal therapy

Lanthanide-doped nanoparticles have long been stereotyped for optical luminescence bioimaging. However, they are known to be unable to produce therapeutic abilities. Here, we describe a lanthanide-based theranostic agent, namely, prussian blue (PB)-coated NaErF4@NaYF4@NaNdF4 core/shell/shell nanocrystals encapsulated in a phospholipid PEG micelle (PEG-CSS@PB), which showed switched imaging and hyperthermia abilities under distinct near infrared (NIR) light activation. The erbium (Er3+)-enriched inner core nanocrystals (NaErF4) enabled the emission of tissue-penetrating luminescence (1525 nm) in the second biological window (NIR-II, 1000-1700 nm), which endowed high-resolution optical imaging of the blood vessels and tumors under ∼980 nm excitation. High neodymium (Nd3+) concentrations in the epitaxial outer NaNdF4 shell introduced maximum cross relaxation processes that converted the absorbed NIR light (∼808 nm) into heat at high efficiencies, thus providing abilities for photothermal therapy (PTT). Importantly, the coated Prussian blue (PB) increased light absorption by about 10-fold compared to the composite free of PB, thus entailing a high light-to-heat conversion efficiency of ∼50.5%. This commensurated with that of well-established gold nanorods. As a result, the PEG-CSS@PB nanoparticles with MTT-determined low toxicities resulted in ∼80% death of HeLa cells at a dose of 600 μg mL-1 under 808 nm laser irradiance (1 W cm-2) for 10 min. Moreover, utilizing the same light dose, a single PTT treatment in tumor-bearing BALB/c mice shrunk the tumor size by ∼12-fold compared to the tumors without treatment. Our results, here, constituted a solid step forward to entitle lanthanide-based nanoparticles as theranostic agents in nanomedicine studies.

Hyaluronic Acid-Modified Porous Carbon-Coated Fe3O4 Nanoparticles for Magnetic Resonance Imaging-Guided Photothermal/Chemotherapy of Tumors

Chemotherapy is an effective method for treating cancer, clinically. However, side effects of drug and multidrug resistance restrict its application. In recent years, the combined treatment of chemotherapy and photothermal therapy (PTT) is becoming a promising method for treating cancer. PTT utilizes nanomaterials absorbing near-infrared light and producing heat to acquire advanced hyperthermia strategy for cancer treatment. Carbon nanomaterials with good biocompatibility, high surface area, and excellent photothermal properties are an excellent nanoplatform for drug delivery and PTT. Herein, porous carbon-coated magnetite nanoparticles (PCCMNs) were successfully synthesized by a one-pot solvothermal method. Magnetite, a contrast agent, can be used for magnetic resonance imaging. Hyaluronic acid was used to modify the PCCMNs to achieve targeted therapy. The obtained nanohybrid with a good photothermal effect can realize combined PTT/chemotherapy and will be a promising nanoplatform for high efficacy theranostics.

Visible light-induced apoptosis activatable nanoparticles of photosensitizer-DEVD-anticancer drug conjugate for targeted cancer therapy

The therapeutic efficacy of photodynamic therapy (PDT) in cancer treatment is attributed to the conversion of tumor oxygen into reactive singlet oxygen (¹O₂) using photosensitizers. However, poor tissue penetration and rapid oxygen depletion have limited the effectiveness of PDT. Therefore, we have developed visible light-induced apoptosis activatable nanoparticles of the photosensitizer (Ce6)-caspase 3 cleavable peptide (Asp-Glu-Val-Asp, DEVD)-anticancer drug monomethyl auristatin E (MMAE) conjugate, resulting in Ce6-DEVD-MMAE nanoparticles. The average size of self-assembled Ce6-DEVD-MMAE nanoparticles was 90.8 ± 18.9 nm. Compared with conventional PDT based on high-energy irradiation, the new therapy uses lower-energy irradiation to induce apoptosis of cancer cells, and activation of caspase 3 to successfully cleave the anticancer drug MMAE from the Ce6-DEVD-MMAE nanoparticles, resulting in strong cytotoxic effects in cancer cells. Notably, the one-time activation of MMAE in the Ce6-DEVD-MMAE nanoparticles further amplified the cytotoxic effect resulting in additional cell death in the absence of visible light irradiation. Furthermore, Ce6-DEVD-MMAE nanoparticles passively accumulated in the targeted tumor tissues via enhanced permeation and retention (EPR) effect in mice with squamous cell carcinoma (SCC7). The high levels of toxicity were retained after exposure to lower-energy irradiation. However, Ce6-DEVD-MMAE nanoparticles did not show any toxicity in the absence of exposure to visible light irradiation, in contrast to the toxicity of free MMAE (1-10 nM). Thus, the light-induced therapeutic strategy based on apoptotic activation of Ce6-DEVD-MMAE nanoparticles can be used to treat solid tumors inaccessible to conventional PDT.

A stage-specific cancer chemotherapy strategy through flexible combination of reduction-activated charge-conversional core-shell nanoparticles

Precision medicine has increased the demand for stage-specific cancer chemotherapy. Drugs with different properties are needed for different stages of tumor development, which is, inducing rapid destruction in the early stage and facilitating deep penetration in the advanced stage. Herein, we report a novel reduction-activated charge-conversional core-shell nanoparticle (CS NP) formula based on ring-closing metathesis of the thiamine disulfide system (TDS) to deliver the chemotherapeutic agent-gambogic acid (GA). Methods: The shell consisted of hyaluronic acid-all-trans retinoid acid with a disulfide bond as the linker (HA-SS-ATRA). The core was selected from poly (γ-glutamic acid) with different grafting rates of the functional group (Fx%) of TDS. GA/CF100%S NPs, with the strongest reduction-responsive drug release, and GA/CF60%S NPs with the strongest penetration have been finally screened. On this basis, a stage-specific administration strategy against a two-stage hepatocellular carcinoma was proposed. Results: The developed CS NPs have been confirmed as inducing reduction-activated charge conversion from about -25 to +30 mV with up to 95% drug release within 48 h. The administration strategy, GA/CF100%S NPs for the early-stage tumor, and sequential administration of GA/CF60%S NPs followed by GA/CF100%S NPs for the advanced-stage tumor, achieved excellent tumor inhibition rates of 93.86±2.94% and 90.76±6.43%, respectively. Conclusions: Our CS NPs provide a novel platform for charge conversion activated by reduction. The stage-specific administration strategy showed great promise for cancer therapy.

Chitosan-mediated green synthesis and folic-acid modification of CuS quantum dots for photoacoustic imaging guided photothermal therapy of tumor

CuS nanomaterials capped with artificial organic-molecules or polymers have been well demonstrated as efficient photothermal nanoagents for the therapy of tumor, but their biocompatibility and target ability should be improved. To address these problems, we have used chitosan (CS) as the biomacromolecule model and surface ligands to prepare CuS quantum dots (QDs) via a simple co-precipitation method. CuS-CS QDs are then conjugated with folic acid (FA). The resulting CuS-CS-FA QDs are composed of hexagonal phase nanodots with sizes of about 4 nm. FA modification process has no apparent influence on the size, phase and composition of the QDs. Furthermore, the zeta potential and infrared spectroscopy confirm the efficient conjugation of FA. CuS-CS-FA QDs exhibit strong near-infrared photoabsorption and high photothermal efficiency (47.0%). As a result of the presence of CS ligand and FA modification, CuS-CS-FA QDs have good biocompatibility and relatively high cellular uptake efficacy. When CuS-CS-FA QD dispersion is injected intravenously into the tumor-bearing mice, the photoacoustic imaging reveals that CuS-CS-FA QD can be efficiently targeted and accumulated in the tumor and reach the peak dose at 60 min. The irradiation of 1064-nm laser (1.0 W cm^-2, 10 min) results in the efficient inhibition of tumor growth, without treatment-induced toxicity. Therefore, CuS-CS-FA QDs have great potential to become biocompatible multifunctional nanoagents for imaging guided therapy of tumor.