Programmed Stimuli-Responsive Carbon Dot-Nanogel Hybrids for Imaging-Guided Enhanced Tumor Phototherapy

Three-Level Nanoparticle Rocket Strategy for Colorectal Cancer Therapeutics in Photothermal Therapy, Inflammation Modulation, and Cuproptosis Induction

Disturbances in intracellular copper (Cu) homeostasis can trigger cuproptosis, a new form of cell death, which, when combined with photothermal therapy (PTT), offers a promising solution to the persistent challenges in colorectal cancer (CRC) treatment. In this study, a "three-level nanoparticle rocket" strategy is developed by engineering Cu5.4O, a multifunctional Cu-based nanoenzyme that is photothermal and has electron transfer properties and antioxidant efficiency. Cu5.4O effectively remodels the inflammatory environment by scavenging reactive oxygen species, thereby overcoming the traditional limitations of PTT. Concurrently, Cu5.4O releases substantial amounts of Cu+ into malignant cells, disrupting Cu homeostasis, inducing cuproptosis, and ultimately inhibiting tumor progression. In vivo and in vitro experiments demonstrate that Cu5.4O operates through multiple successive and interlocking stages to significantly eradicate tumors, prevent relapse, and prolong survival. This study provides profound insights into the synergistic effects of PTT, inflammatory regulation, and cuproptosis within the complex tumor microenvironment, presenting innovative approaches for future CRC therapy.

Phenylboronic acid-modified carbon dot-proteinase K nanohybrids for enhanced photodynamic therapy against bacterial biofilm infections

Nanohybrids combining phenylboronic acid-modified carbon dots (PCDs) and proteinase K have been engineered for addressing the formidable challenges of antimicrobial photodynamic therapy (aPDT) against bacterial biofilm infections, overcoming biofilm barrier obstruction, the limited diffusion of reactive oxygen species (ROS), and the inadequate ROS generation of traditional photosensitizers. PCDs are formulated for superior water solubility and robust singlet oxygen (1O2) production, mitigating issues related to dispersion and aggregation-induced quenching typical of conventional photosensitizers. The conjugation of phenylboronic acid to CDs not only enhanced 1O2 generation through increased electron-hole separation but also imparted strong bacterial binding capabilities to the PCDs, enabling broad-spectrum sterilization by maximizing the ROS-mediated bacterial destruction. Proteinase K, serving as a structural "glue", actively breaks down biofilms and facilitates the deep penetration of functional PCDs, aiding effective treatment of biofilm infections. In vivo studies confirm that PCDs-proteinase K nanohybrids dramatically accelerate healing in biofilm-infected wounds by synergizing enhanced photosensitization, potent bacterial adherence, and efficient biofilm elimination and penetration. This approach highlights a straightforward strategy to significantly advance aPDT, promoting the clinical adoption of non-antibiotic methods for combating bacterial biofilm infections. STATEMENT OF SIGNIFICANCE: 1) Phenylboronic acid-modified carbon dots (PCDs) were designed for enhanced water solubility and efficient singlet oxygen generation through surface modulation, also suggesting that surface modification can improve the inherent photosensitizing activity of CDs by promoting electron-hole separation; 2) The conjugation of phenylboronic acid endowed PCDs with strong bacterial binding capabilities, enabling highly efficient and broad-spectrum sterilization by maximizing reactive oxygen species-mediated bacterial destruction; 3) Incorporation of proteinase K (PK) leveraged its specific extracellular polymeric substance degrading capability, along with the stimuli-responsive release of PCDs from the PCDs-PK nanohybrids, facilitating biofilm breakdown and enabling deeper penetration of PCDs, thereby improving the treatment of biofilm infections.

Biomimetic Cerium-Assisted Supra-Carbon Dots Assembly for Reactive Oxygen Species-Activated Atherosclerosis Theranostic

Theranostic applications in atherosclerosis plaque microenvironment-triggered nanoplatforms are significantly compromised by the complex synthesis procedure, non-specific distribution, and limited therapeutic function. Therefore, development of a facile and feasible method to construct a pathology-based stimuli-responsive nanoplatform with satisfactory theranostic performance remains a demanding and highly anticipated goal. Herein, a novel class of multifunctional supra-carbon dots (CDs), denoted as MM@Ce-CDs NPs, by a simple nanoassembly and a subsequent coating with macrophage membrane (MM), is developed for the targeted reactive oxygen species-trigged theranostic and positive regulation of the pathological plaque microenvironment in AS. The harvested MM@Ce-CDs NPs exhibit activatable fluorescence properties, photoacoustic characteristics, and cascade enzyme performances, which can be effectively activated under ROS stimulation in the plaque pathological microenvironment, enabling precise control over theranostic functions, while markedly enhancing diagnostic accuracy and therapeutic efficacy for AS management. Besides, MM@Ce-CDs NPs can effectively manipulate the plaque microenvironment by reducing ROS levels and inflammation, alleviating M1 macrophage infiltration, and inhibiting foam cell formation, all together suppressing the pathological plaque development through the synergistic mechanisms. In addition, MM@Ce-CDs NPs inherit the biomimetic biological functions from MM, facilitating a highly specific target delivery to AS.

Metal-phenolic network crosslinked nanogel with prolonged biofilm retention for dihydroartemisinin/NIR synergistically enhanced chemodynamic therapy

Chemodynamic therapy (CDT) is emerging as a promising treatment for biofilm infections. However, its effectiveness is significantly hindered by several factors: the body's stable temperature, a limited supply of Fe2+ ions, and inadequate endogenous levels of H2O2 at the infection sites. Herin, our study introduces MPN-crosslinked hyaluronic acid (HA) nanogels as an effective strategy for treating biofilm-associated infections. The DHA@HA-TA/Fe (DHTF) nanogel is synthesized through the coordination reaction between Fe2+ ions and tannic acid (TA)-modified HA, with dihydroartemisinin (DHA) encapsulated within the structure. DHTF exhibits pH-/hyaluronidase-responsiveness in the biofilm infection microenvironment, enabling sustained release of DHA as a substitute for H2O2 and Fe2+ for CDT. The incorporation of Fe2+/TA-based MPN and DHA within the nanogels enables photothermal/DHA dually-enhanced CDT, facilitating efficient disruption of biofilm matrices and bacterial eradication through boosting reactive oxygen species production. In vivo studies demonstrate that DHTF exhibit prolonged retention within biofilms. This ensures a sustained release of therapeutic agents and continuous anti-biofilm activity. Eventually, both in vitro and in vivo evaluations consistently confirm the significant anti-biofilm capacity of DHTF. Our findings highlight the potential of DHTF as a promising nanomedicine for biofilm-related infections, offering efficient treatment strategies that could improve clinical management of these challenging conditions.

Carbon-based Nanomaterials in Photothermal Therapy Guided by Photoacoustic Imaging: State of Knowledge and Recent Advances

Carbon-based nanomaterials (CBNM) have been widely used in various fields due to their excellent physicochemical properties. In particular, in the area of tumor diagnosis and treatment, researchers have frequently reported them for their potential fluorescence, photoacoustic (PA), and ultrasound imaging performance, as well as their photothermal, photodynamic, sonodynamic, and other therapeutic properties. As the functions of CBNM are increasingly developed, their excellent imaging properties and superior tumor treatment effects make them extremely promising theranostic agents. This review aims to integrate the considered and researched information in a specific field of this research topic and systematically present, summarize, and comment on the efforts made by authoritative scholars. In this review, we summarized the work exploring carbon-based materials in the field of tumor imaging and therapy, focusing on PA imaging-guided photothermal therapy (PTT) and discussing their imaging and therapeutic mechanisms and developments. Finally, the current challenges and potential opportunities of carbon-based materials for PA imaging-guided PTT are presented, and issues that researchers should be aware of when studying CBNM are provided.

Advances in Carbon Dot Based Enhancement of Photodynamic Therapy of Tumors

Photodynamic therapy has advantages of high selectivity, less invasiveness, and high lethality for cancer cells compared with traditional treatment methods. However, some problems have hindered the development of photodynamic therapy, such as limited penetration depth, lack of oxygen, and toxicity. Carbon dots are widely used in the imaging and treatment of tumors due to their excellent optical and physicochemical properties, so effective methods have been explored to address the issues in photodynamic therapy via carbon dots. This review aims to elucidate the role of carbon dots in photodynamic therapy of cancer. Moreover, we summarize and discuss some strategies to harness carbon dots to enhance photodynamic therapy. Finally, we summarize many cancer synergistic therapeutic modalities involving carbon dots such as chemodynamic therapy, photothermal therapy, and immunotherapy in combination with photodynamic therapy to achieve more effective and safer treatments.

Recent advances in near-infrared stimulated nanohybrid hydrogels for cancer photothermal therapy

Nanomedicine has emerged as a promising avenue for advancing cancer treatment, but the challenge of mitigating its in vivo side effects necessitates the development of innovative structures and materials. Recent investigation has unveiled nanogels as particularly compelling candidates, characterized by a porous, three-dimensional network architecture that exhibits exceptional drug loading capacity. Beyond this, nanogels boast a substantial specific surface area and can be tailored with specific chemical functionalities. Consequently, nanogels are frequently engineered as a multi-modal synergistic platform for combating cancer, wherein photothermal therapy stands out due to its capacity to penetrate deep tissues and achieve localized tumor eradication through the application of elevated temperatures. In this review, we delve into the synthesis of diverse varieties of photothermal nanogels capable of controlled drug release triggered by either chemical or physical stimuli. It also summarizes their potential for synergistic integration with photothermal therapy alongside other therapeutic modalities to realize effective tumor ablation. Moreover, we analyze the primary mechanisms underlying the contribution of photothermal nanogels to cancer treatment while underscoring their adeptness in regulating therapeutic temperatures for repairing bone defects resulting from tumor-associated trauma. Envisioned as an auspicious strategy in the realm of cancer therapy, photothermal nanogels hold promise for furnishing controlled drug delivery and precise thermal ablation capabilities.

Orange carbon dots based smart sensing platforms for rapid, visual, quantitative identification of sodium copper chlorophyllin

A highly affordable, sensitive and portable detection platform for the quantitative identification of sodium copper chlorophyllin (SCC) in food and environment is a crucial need. Even though many carbon dots (CDs) based sensors have been developed, few reports on using CDs as optical probes for SCC detection have been published so far. In this paper, orange luminescent CDs (OLCDs) were prepared via solvothermal method, which have high fluorescence quantum yield (27.20 %) and excellent photostability. OLCDs can detect SCC via inner filter effect (IFE), with fast response, high selectivity, outstanding sensitivity and superior anti-interference ability. Benefiting from the remarkable properties of OLCDs, a portable sensing platform was triumphantly constructed, which facilitated the in situ, real-time quantitative determination of SCC in diverse actual samples, by catching the fluorescence change of OLCDs-based paper sensors via smartphone RGB colorimetric analysis. This first CDs-based smart sensing system displays great potential for quantification of SCC in various fields.

Theranostic nanogels: multifunctional agents for simultaneous therapeutic delivery and diagnostic imaging

In recent years, there has been a growing interest in multifunctional theranostic agents capable of delivering therapeutic payloads while facilitating simultaneous diagnostic imaging of diseased sites. This approach offers a comprehensive strategy particularly valuable in dynamically evolving diseases like cancer, where combining therapy and diagnostics provides crucial insights for treatment planning. Nanoscale platforms, specifically nanogels, have emerged as promising candidates due to their stability, tunability, and multifunctionality as carriers. As a well-studied subgroup of soft polymeric nanoparticles, nanogels exhibit inherent advantages due to their size and chemical compositions, allowing for passive and active targeting of diseased tissues. Moreover, nanogels loaded with therapeutic and diagnostic agents can be designed to respond to specific stimuli at the disease site, enhancing their efficacy and specificity. This capability enables fine-tuning of theranostic platforms, garnering significant clinical interest as they can be tailored for personalized treatments. The ability to monitor tumor progression in response to treatment facilitates the adaptation of therapies according to individual patient responses, highlighting the importance of designing theranostic platforms to guide clinicians in making informed treatment decisions. Consequently, the integration of therapy and diagnostics using theranostic platforms continues to advance, offering intelligent solutions to address the challenges of complex diseases such as cancer. In this context, nanogels capable of delivering therapeutic payloads and simultaneously armed with diagnostic modalities have emerged as an attractive theranostic platform. This review focuses on advances made toward the fabrication and utilization of theranostic nanogels by highlighting examples from recent literature where their performances through a combination of therapeutic agents and imaging methods have been evaluated.

Hybrid Nanogel Drug Delivery Systems: Transforming the Tumor Microenvironment through Tumor Tissue Editing

The future of drug delivery offers immense potential for the creation of nanoplatforms based on nanogels. Nanogels present a significant possibility for pharmaceutical advancements because of their excellent stability and effective drug-loading capability for both hydrophobic and hydrophilic agents. As multifunctional systems, composite nanogels demonstrate the capacity to carry genes, drugs, and diagnostic agents while offering a perfect platform for theranostic multimodal applications. Nanogels can achieve diverse responsiveness and enable the stimuli-responsive release of chemo-/immunotherapy drugs and thus reprogramming cells within the TME in order to inhibit tumor proliferation, progression, and metastasis. In order to achieve active targeting and boost drug accumulation at target sites, particular ligands can be added to nanogels to improve the therapeutic outcomes and enhance the precision of cancer therapy. Modern "immune-specific" nanogels also have extra sophisticated tumor tissue-editing properties. Consequently, the introduction of a multifunctional nanogel-based drug delivery system improves the targeted distribution of immunotherapy drugs and combinational therapeutic treatments, thereby increasing the effectiveness of tumor therapy.

Target Functionalized Carbon Dot Nanozymes with Dual-Model Photoacoustic and Fluorescence Imaging for Visual Therapy in Atherosclerosis

Multifunctional nanomedicines have been used in atherosclerosis theranostics. Herein, phosphatidylserine-specific peptide CLIKKPF-functionalized carbon-dots nanozymes (pep-CDs) are reported for specific and efficient noninvasive theranostic of atherosclerosis. Surprisingly, pep-CDs are discovered to not only inherit the inherent properties of carbon dots (CDs), including deep-red fluorescence emission, photoacoustic response, and superoxide dismutase-like antioxidant, and anti-inflammatory activities but also possess the ability to target recognition on foam cells and target localization on plaques due to the specific interaction of CLIKKPF with phosphatidylserine on the membrane outer surface of foam cells. Furthermore, the target localization effect of pep-CDs vastly promotes the efficient accumulation of CDs in plaque, thus maximizing AS theranostic of CDs. Interestingly, pep-CDs could be developed to image plaque for monitoring atherosclerosis pathological progression in real-time resulting from the different content of foam cells. This work on the one hand proposes a simple and feasible strategy to construct theranostic nanoplatform employing only a single functional unit (i.e., multifunctional CDs) to simplify the fabrication procedure, on the other hand, highlights the advantages of the active target auxiliary mode for atherosclerosis theranostic applications.

Multifunctional Carbon Dots for Biomedical Applications: Diagnosis, Therapy, and Theranostic

Designing suitable nanomaterials is an ideal strategy to enable early diagnosis and effective treatment of diseases. Carbon dots (CDs) are luminescent carbonaceous nanoparticles that have attracted considerable attention. Through facile synthesis, they process properties including tunable light emission, low toxicity, and light energy transformation, leading to diverse applications as optically functional materials in biomedical fields. Recently, their potentials have been further explored, such as enzyme-like activity and ability to promote osteogenic differentiation. Through refined synthesizing strategies carbon dots, a rich treasure trove for new discoveries, stand a chance to guide significant development in biomedical applications. In this review, the authors start with a brief introduction to CDs. By presenting mechanisms and examples, the authors focus on how they can be used in diagnosing and treating diseases, including bioimaging failure of tissues and cells, biosensing various pathogenic factors and biomarkers, tissue defect repair, anti-inflammation, antibacterial and antiviral, and novel oncology treatment. The introduction of the application of integrated diagnosis and treatment follows closely behind. Furthermore, the challenges and future directions of CDs are discussed. The authors hope this review will provide critical perspectives to inspire new discoveries on CDs and prompt their advances in biomedical applications.

Exploring the Potential of Nanogels: From Drug Carriers to Radiopharmaceutical Agents

Nanogels open up access to a wide range of applications and offer among others hopeful approaches for use in the field of biomedicine. This review provides a brief overview of current developments of nanogels in general, particularly in the fields of drug delivery, therapeutic applications, tissue engineering, and sensor systems. Specifically, cyclodextrin (CD)-based nanogels are important because they have exceptional complexation properties and are highly biocompatible. Nanogels as a whole and CD-based nanogels in particular can be customized in a wide range of sizes and equipped with a desired surface charge as well as containing additional molecules inside and outside, such as dyes, solubility-mediating groups or even biological vector molecules for pharmaceutical targeting. Currently, biological investigations are mainly carried out in vitro, but more and more in vivo applications are gaining importance. Modern molecular imaging methods are increasingly being used for the latter. Due to an extremely high sensitivity and the possibility of obtaining quantitative data on pharmacokinetic and pharmacodynamic properties, nuclear methods such as single photon emission computed tomography (SPECT) and positron emission tomography (PET) using radiolabeled compounds are particularly suitable here. The use of radiolabeled nanogels for imaging, but also for therapy, is being discussed.

Development of a Temperature-Responsive Hydrogel Incorporating PVA into NIPAAm for Controllable Drug Release in Skin Regeneration

Melanoma, a highly malignant and aggressive form of skin cancer, poses a significant global health threat, with limited treatment options and potential side effects. In this study, we developed a temperature-responsive hydrogel for skin regeneration with a controllable drug release. The hydrogel was fabricated using an interpenetrating polymer network (IPN) of N-isopropylacrylamide (NIPAAm) and poly(vinyl alcohol) (PVA). PVA was chosen for its adhesive properties, biocompatibility, and ability to address hydrophobicity issues associated with NIPAAm. The hydrogel was loaded with doxorubicin (DOX), an anticancer drug, for the treatment of melanoma. The NIPAAm-PVA (N-P) hydrogel demonstrated temperature-responsive behavior with a lower critical solution temperature (LCST) around 34 °C. The addition of PVA led to increased porosity and faster drug release. In vitro biocompatibility tests showed nontoxicity and supported cell proliferation. The N-P hydrogel exhibited effective anticancer effects on melanoma cells due to its rapid drug release behavior. This N-P hydrogel system shows great promise for controlled drug delivery and potential applications in skin regeneration and cancer treatment. Further research, including in vivo studies, will be essential to advance this hydrogel system toward clinical translation and impactful advancements in regenerative medicine and cancer therapeutics.

Recent Advances of Tumor Microenvironment-Responsive Nanomedicines-Energized Combined Phototherapy of Cancers

Photodynamic therapy (PDT) has emerged as a powerful tumor treatment tool due to its advantages including minimal invasiveness, high selectivity and thus dampened side effects. On the other side, the efficacy of PDT is severely frustrated by the limited oxygen level in tumors, thus promoting its combination with other therapies, particularly photothermal therapy (PTT) for bolstered tumor treatment outcomes. Meanwhile, nanomedicines that could respond to various stimuli in the tumor microenvironment (TME) provide tremendous benefits for combined phototherapy with efficient hypoxia relief, tailorable drug release and activation, improved cellular uptake and intratumoral penetration of nanocarriers, etc. In this review, we will introduce the merits of combining PTT with PDT, summarize the recent important progress of combined phototherapies and their combinations with the dominant tumor treatment regimen, chemotherapy based on smart nanomedicines sensitive to various TME stimuli with a focus on their sophisticated designs, and discuss the challenges and future developments of nanomedicine-mediated combined phototherapies.

Recent Progress on Chiral Carbon Dots: Synthetic Strategies and Biomedical Applications

The discovery of chiral carbon dots (Ch-CDs) has opened up an exciting new research direction in the field of carbon dots. It not only retains the chirality of the precursor and exhibits highly symmetric chiral optical properties but also has properties such as chemical stability, antibacterial and antitumor properties, and good biocompatibility of carbon dots. Based on these advantages, the application of Ch-CDs in the biomedical field has attracted significant interest among researchers. However, a comprehensive review of the selection of precursors for Ch-CDs, preparation methods, and applications in biomedical fields is still lacking. Here, we summarize their precursor selection and preparation methods based on recent reports on Ch-CDs and provide the first comprehensive review for specific applications in biomedical engineering, such as biosensing, bioimaging, drug carriers, antibacterial and antibiofilm, and enzyme activity modulation. Finally, we discuss application prospects and challenges that need to be overcome. We hope this review will provide valuable guidance for researchers to prepare novel Ch-CDs and facilitate their application in biomedical engineering.

Multi-functional auto-fluorescent nanogels for theranostics

Here in the present article, the state of art for nanotechnology-enabled nanogel theranostics and the upcoming concepts in nanogel-based therapeutics are summarized. The benefits, innovation, and prospects of nanogel technology are also briefly presented.

A Single Carbon-Dot System Enabling Multiple Stimuli Activated Room-Temperature Phosphorescence

Room-temperature phosphorescent carbon dots (RTPCDs) have attracted considerable interests due to their unique nanoluminescent characteristic with time resolution. However, it is still a formidable challenge to construct multiple stimuli-activated RTP behaviors on CDs. Since the address of this issue facilitates complex and high-regulatable phosphorescent applications, we here develop a novel strategy to achieve a multiple stimuli responsive phosphorescent activation on a single carbon-dot system (S-CDs), using persulfurated aromatic carboxylic acid as the precursor. The introduction of aromatic carbonyl groups and multiple S atoms can promote the intersystem crossing process to generate RTP characteristic of the produced CDs. Meanwhile, by introducing these functional surface groups into S-CDs, the RTP property can be activated by light, acid, and thermal stimuli in solution or in film state. In this way, multistimuli responsive and tunable RTP characteristics are realized in the single carbon-dot system. Based on this set of RTP properties, S-CDs is applied to photocontrolled imaging in living cells, anticounterfeit label, and multilevel information encryption. Our work will benefit the development of multifunctional nanomaterials together with extending their application scope.

Carbon-Based Stimuli-Responsive Nanomaterials: Classification and Application

Carbon-based nanomaterials, including carbon nanotubes, carbon nanospheres, and carbon nanofibers, are becoming a research hotspot due to their unique structure and good mechanical, thermal, electrical, optical, and chemical properties. With the development of material synthesis technology, they can be functionalized and used in various fields such as energy, environment, and biomedicine. In particular, stimuli-responsive carbon-based nanomaterials have stood out in recent years because of their smart behavior. Researchers have applied carbon-based nanomaterials to different disease treatments based on their stimulus-response properties. In this paper, based on stimuli-responsive carbon-based nanomaterials' morphology, we categorize them into carbon nanotubes, carbon nanospheres, and carbon nanofibers according to their morphology. Then, their applications in probes, bioimaging, tumor therapy, and other fields are discussed. Finally, we address the advantages and disadvantages of carbon-based stimuli-responsive nanomaterials and discuss their future perspective.

Carbon Dot-Based Hydrogels: Preparations, Properties, and Applications

Hydrogels have extremely high moisture content, which makes it very soft and excellently biocompatible. They have become an important soft material and have a wide range of applications in various fields such as biomedicine, bionic smart material, and electrochemistry. Carbon dot (CD)-based hydrogels are based on carbon dots (CDs) and auxiliary substances, forming a gel material with comprehensive properties of individual components. CDs embedding in hydrogels could not only solve their aggregation-caused quenching (ACQ) effect, but also manipulate the properties of hydrogels and even bring some novel properties, achieving a win-win situation. In this review, the preparation methods, formation mechanism, and properties of CD-based hydrogels, and their applications in biomedicine, sensing, adsorption, energy storage, and catalysis -are summarized. Finally, a brief discussion on future research directions of CD-based hydrogels will be given.

Specific Chemiluminescence Imaging and Enhanced Photodynamic Therapy of Bacterial Infections by Hemin-Modified Carbon Dots

Antibacterial photodynamic therapy (aPDT) is a promising antibiotics-alternative strategy for bacterial infectious diseases, which features broad-spectrum antibacterial activity with a low risk of inducing bacterial resistance. However, clinical applications of aPDT are still hindered by the hydrophobicity-caused inadequate photodynamic activity of conventional photosensitizers and the hypoxic microenvironment of bacterial infections. To address these problems, herein, a promising strategy is developed to achieve specific chemiluminescence (CL) imaging and enhanced PDT of bacterial infections using hemin-modified carbon dots (H-CDs). The H-CDs can be facilely prepared and exhibit favorable water solubility, augmented photodynamic activity, and unique peroxidase-mimicking capacity. Compared with the free CDs, the photodynamic efficacy of H-CDs is significantly augmented due to the increased electron-hole separation efficiency. Moreover, the peroxidase catalytic performance of H-CDs enables not only infection identification via bacterial infection microenvironment-responsive CL imaging but also oxygen self-supplied aPDT with hypoxia-relief-enhanced bacteria inactivation effects. Finally, the enhanced aPDT efficiencies of H-CDs are validated in both in vivo abscess and infected wound models. This work may provide an effective antibacterial platform for the selective imaging-guided treatment of bacterial infections.

Product from sessile droplet evaporation of PNIPAM/water system above LCST: A block or micro/nano-particles?

PNIPAM as a stimuli-responsive polymer has generated extreme interests due to its versatile applications. However, there is no research report on whether PNIPAM micro/nano-particles can be extracted from its suspension after phase separation. In the present work, LCST-type phase separation in self-synthesized PNIPAM/water system was investigated in depth by dividing the DLS testing process into four stages. In addition to quenching duration, temperature rise process, quenching temperature and PNIPAM concentration all have a great influence on particle size of the suspension. Meanwhile, the steady-state rheology and dynamic viscoelasticity results show that PNIPAM micro/nano-particles in the suspension are "soft" that can deform. Finally, FE-SEM was used to observe the morphology of dehydrated PNIPAM extracted by sessile droplet evaporation under different conditions. The results indicate that these "soft" particles are easier to fuse together, do not have sufficient mechanical strength to maintain their spherical morphology after dehydration. But the above fusion can be suppressed by adjusting evaporation conditions to acquire smaller PNIPAM particles which have sufficient mechanical properties to keep their basic particle morphology. Further, by changing evaporation pressure to positive or negative pressure, dehydrated PNIPAM micro/nano-particles with excellent uniformity and separation can be obtained. This work will provide guidance for extracting micro/nano-particles from polymer/diluent systems with LCST.

Copper-Nitrogen-Coordinated Carbon Dots: Transformable Phototheranostics from Precise PTT/PDT to Post-Treatment Imaging-Guided PDT for Residual Tumor Cells

Phototheranostics has attracted considerable attention in the fields of cancer diagnosis and treatment. However, the complete eradication of solid tumors using traditional phototheranostics is difficult because of the limited depth and range of laser irradiation. New phototheranostics enabling precise phototherapy and post-treatment imaging-guided programmed therapy for residual tumors is urgently required. Accordingly, this study developed a novel transformable phototheranostics by assembling hyaluronic acid (HA) with copper-nitrogen-coordinated carbon dots (CDs). In this transformable nanoplatform, named copper-nitrogen-CDs@HA, the HA component enables the specific targeting of cluster determinant (CD) 44-overexpressing tumor cells. In the tumor cells, redox glutathione converts Cu(II) (cupric ions) into Cu(I) (cuprous ions), which confers the novel transformable functionality to phototheranostics. Both in vitro and in vivo results reveal that the near-infrared-light-photoactivated Cu^II-N-CDs@HA could target CD44-overexpressing tumor cells for precise synergistic photothermal therapy and photodynamic therapy. This study is the first to observe that Cu^II-N-CDs@HA could escape from lysosomes and be transformed in situ into Cu^I-N-CDs@HA in tumor cells, with the d⁹ electronic configuration of Cu(II) changing to the d¹⁰ electronic configuration of Cu(I), which turns on their fluorescence and turns off their photothermal properties. This transformable phototheranostics could be used for post-treatment imaging-guided photodynamic therapy on residual tumor cells. Thus, the rationally designed copper-nitrogen-coordinated CDs offer a simple in situ transformation strategy for using multiple-stimulus-responsive precise phototheranostics in post-treatment monitoring of residual tumor cells and imaging-guided programmed therapy.

Carbonaceous Nanomaterials for Phototherapy of Cancer

Carbonaceous nanomaterials (CNMs) have drawn tremendous biomedical research interest because of their unique structural features. Recently, CNMs, namely carbon dots, fullerenes, graphene, etc, have been successful in establishing them as considerable nanotherapeutics for phototherapy applications due to their electrical, thermal, and surface properties. This review aims to crosstalk the current understanding of CNMs as multimodal compounds in photothermal and photodynamic therapies as an integrated approach to treating cancer. It also expounds on phototherapy's biomechanics and illustrates its relation to cancer biomodulation. Critical considerations related to the structural properties, fabrication approaches, surface functionalization strategies, and biosafety profiles of CNMs have been explained. This article provides an overview of the most recent developments in the study of CNMs used in phototherapy, emphasizing their usage as nanocarriers. To conquer the current challenges of CNMs, we can raise the standard of cancer therapy for patients. The review will be of interest to the researchers working in the area of photothermal and photodynamic therapies and aiming to explore CNMs and their conjugates in cancer therapy.