Photothermal Therapy Systems Research Articles

Supramolecular Porphyrin Photosensitizers Based on Host-Guest Recognition for In Situ Bacteria-Responsive Near-Infrared Photothermal Therapy.

Antibiotic resistance resulting from the overuse of antibiotics sets a high challenge for brutal antimicrobial treatment. Although photothermal therapy (PTT) overcomes the awkward situation of antibiotic resistance, it usually mistakenly kills the beneficial bacteria strains when eliminating pernicious bacteria. Specifically recognizing and damaging the target pathogens is urgently required for PTT-mediated sterilization strategy. Based on the host-guest recognition between cucurbit[10]uril (CB[10]) and porphyrins, two water-soluble supramolecular porphyrins are designed and implement selective bactericidal effect via in situ bacteria-responsive near-infrared (NIR) PTT. With the help of CB[10], the π-π stacking and hydrophobic interactions of porphyrins are efficiently inhibited, thus contributing to a good photostability and a high photothermal conversion efficiency. Attributing to the matching reduction potential between facultative anaerobic Escherichia coli (E. coli) and porphyrins, they are selectively in situ reduced into supramolecular phlorin and supramolecular chlorin by E. coli, successfully achieving a selective sterilization against E. coli. In vivo, the in situ bacteria-responsive NIR PTT systems also promote the quick recovery of E. coli-infected abscesses and trauma on mice without inducing obvious systemic toxicity, providing a new alternative to the current antibiotics and helping relieve the global public health crisis of abusive antibiotics.

Indocyanine Green-Loaded Adhesive Proteinic Nanoparticles for Effective Locoregional and Prolonged Photothermal Anticancer Therapy.

Conventional anticancer therapies, including surgical resection, radiation, and chemotherapy, are the primary modalities for treating various forms of cancer. However, these treatments often bring significant side effects and risk of recurrence, underscoring the need for more targeted and less invasive therapeutic options. To address this challenge, we developed an adhesive nanoparticle (NP)-based effective anticancer photothermal therapy (PTT) system using bioengineered mussel adhesion protein (MAP). The unique underwater tissue adhesive properties of MAP NPs enabled targeted delivery and prolonged retention at the tumor site, thereby improving therapeutic efficacy. Our innovative indocyanine green (ICG)-loaded MAP NPs (MAP@ICG NPs) demonstrated strong photothermal capability and stability, and potent anticancer activity in vitro. In vivo intratumor injection of the MAP@ICG NPs showed remarkable anticancer PTT effects, effectively reducing tumor growth with minimal damage to surrounding tissues. The development and utilization of this adhesive proteinic NP-based PTT system represent a significant advancement in cancer therapy, offering a promising alternative that combines the precision of NP delivery with effective therapeutic efficacy.

Thermoelectric-Feedback Nanocomposite Hydrogel for Temperature-Synchronized Monitoring and Regulation in Accurate Photothermal Therapy.

Photothermal therapy (PTT) is a promising approach for tumor ablation and cancer treatment. However, controlling the therapeutic temperature during treatment remains challenging, and imprecise thermal regulation can harm adjacent healthy tissues, reduce therapeutic accuracy, and promote the thermotolerance of cellular phenotypes, potentially leading to tumor invasion and recurrence. Although existing methods provide basic temperature control by adjusting irradiation power and photothermal agent dosing, they lack real-time temperature monitoring and feedback control capabilities, underscoring the urgent need for more integrated and precise PTT systems. In this context, an innovative photothermoelectric (PTE) cobalt-infused chitosan (CS) nanocomposite hydrogel (PTE-Co@CS) is developed for precise temperature-regulated PTT, exhibiting desirable mechanical properties and exceptional biocompatibility. Enhanced by embedded nanoparticles, PTE-Co@CS demonstrates superior photothermal conversion efficiency compared with existing methods, while also featuring thermoelectric responsiveness and increased sensitivity to photostimuli. Its advantageous PTE response characteristics ensure a linear correlation between temperature shifts and resistance changes (e.g., R2 = 0.99919 at 0.5Wcm⁻2), enabling synchronized qualitative and quantitative control of PTT temperature through electrical signal monitoring. This allows for real-time monitoring and regulation during PTT, effectively addressing the issue of uncontrollable temperatures and improving therapeutic efficacy.

Rational approach to design gold nanoparticles for photothermal therapy: the effect of gold salt on physicochemical, optical and biological properties

Among the unique characteristics associated to gold nanoparticles (AuNPs) in biomedicine, their ability to convert light energy into heat opens ventures for improved cancer therapeutic options, such as photothermal therapy (PTT). PTT relies on the local hyperthermia of tumor cells upon irradiation with light beams, and the association of AuNPs with radiation within the near infrared (NIR) range constitutes an advantageous strategy to potentially improve PTT efficacy. Herein, it was explored the effect of the gold salt on the AuNPs’ physicochemical and optical properties. Mostly spherical-like negatively charged AuNPs with variable sizes and absorbance spectra were obtained. In addition, photothermal features were assessed using in vitro phantom models. The best formulation showed the ability to increase their temperature in aqueous solution up to 19 °C when irradiated with a NIR laser for 20 min. Moreover, scanning transmission electron microscopy confirmed the rearrangement of the gold atoms in a face-centered cubic structure, which further allowed to calculate the photothermal conversion efficiency upon combination of theoretical and experimental data. AuNPs also showed local retention after being locally administered in in vivo models. These last results obtained by computerized tomography allow to consider these AuNPs as promising elements for a PTT system. Moreover, AuNPs showed high potential for PTT by resulting in in vitro cancer cells’ viability reductions superior to 70 % once combine with 5 min of NIR irradiation.

Acid-Responsive Aggregation of Gold Nanoparticles for the Photothermal Treatment of Bacterial Infections.

Photothermal therapy (PTT) is considered to be one of the promising methods to combat pathogenic bacteria. However, traditional PTT is prone to generate undesired temperature increase to surrounding normal tissues, which limits the application of PTT. Herein, an acid-responsive PTT system (Au nanoparticles system: AuNPs-S) was constructed based on the photothermal feature of spherical gold nanoparticles (AuNPs) and the low pH of the bacterial infected site. AuNPs-S is composed of two kinds of AuNPs: AuNPs modified with Asp-Asp-Asp-Asp-Asp-Cys (peptide A) were denoted as AuNPs-A; AuNPs modified with 2,3-dimethylmaleic anhydride (DA) grafted Lys-Gly-Gly-Lys-Gly-Gly-Lys-Cys (peptide B) were denoted as AuNPs-B/DA. AuNPs-B/DA with an acid-responsive moiety showed a charge-convertible feature. The negatively charged AuNPs-B/DA became positively charged AuNPs-B at low pH, aggregating with the negatively charged AuNPs-A via an electrostatic interaction, reaching the threshold to the interparticle plasmonic coupling effect among AuNPs, thereby killing bacteria precisely under the irradiation of near-infrared (NIR) light through the elevated temperature at the targeted area. This acid-responsive PTT strategy supplies an excellent mode for combating bacterial infections with no vital damage to normal tissues.

Thermoresponsive Hydrogel-Enabled Thermostatic Photothermal Therapy for Enhanced Healing of Bacteria-Infected Wounds.

Photothermal therapy (PTT) has emerged as an attractive technique for the treatment of bacterial infections. However, the uncontrolled heat generation in conventional PTT inevitably causes thermal damages to healthy tissues and/or organs. It is thus essential to develop a smart and universal strategy to regulate the photothermal equilibrium temperature to a preset safe threshold. Herein, a thermoresponsive hydrogel-enabled thermostatic PTT system for enhanced healing of bacteria-infected wounds is reported. In this system, the near-infrared (NIR)-triggered heat generation by photothermal nanomaterials is spontaneously transferred to a thermoresponsive hydrogel with a lower critical solution temperature (LCST), leading to its rapid phase transition by forming considerable light-scattering centers to block NIR penetration. Such a dynamic and reversible process automatically regulates the photothermal equilibrium temperature to the phase-transition point of the LCST-type hydrogel. In contrast to temperature-uncontrolled conventional PTT with severe thermal damages, the thermoresponsive hydrogel-enabled thermostatic PTT provides effective protection on healthy tissues and/or organs, which remarkably accelerates wound healing by efficient bacterial eradication. This study establishes a smart, simple and universal PTT platform, holding great promise in the safe and efficient treatment of bacterial skin infections.

Multi-Wavelength Photoacoustic Temperature Feedback Based Photothermal Therapy Method and System.

Photothermal therapy (PTT) is a new type of tumor treatment technology that is noninvasive, repeatable, and does not involve radiation. Owing to the lack of real-time and accurate noninvasive temperature measurement technology in current PTT surgical procedures, empirical and open-loop treatment laser power control mode inevitably leads to overtreatment. Thermal radiation causes irreversible damage to normal tissue around cancer tissue and seriously affects the therapeutic effect of PTT and other therapies conducted at the same time. Therefore, real-time measurement and control of the temperature and thermal damage of the therapeutic target are critical to the success of PTT. To improve the accuracy and safety of PTT, we propose a multi-wavelength photoacoustic (PA) temperature feedback based PTT method and system. PA thermometry information at different wavelengths is mutually corrected, and the therapeutic light dose is regulated in real time to accurately control the treatment temperature. The experimental results on the swine blood sample confirm that the proposed method can realize real-time temperature measurement and control of the target area with an accuracy of 0.56 °C and 0.68 °C, demonstrating its good prospects for application.

Mild-temperature photothermal treatment method and system based on photoacoustic temperature measurement and control

As a non-invasive technology for tumor treatment, photothermal therapy (PTT) is increasingly applied during clinical treatment. However, due to the lack of non-invasive temperature measurement methods, excessive therapeutic light dose will damage the healthy tissue around the lesion. Monitoring and control the therapy temperature during PTT application is necessary to ensure effective therapy while minimizing thermal damage to adjacent tissue. In order to ensure that the therapy temperature in PTT is stable in the mild range (below 43 °C), it is necessary to design a mild-temperature PTT method and system that can detect and control the temperature in real-time. A mild-temperature photothermal treatment method and system based on photoacoustic temperature measurement and control is proposed in this paper. On the basis of reference temperature, the relative temperature change is measured based on the photoacoustic information, and the treatment temperature of the target area is precisely controlled in real time using the closed-loop temperature control algorithm. Based on the experimental results of agar-based phantoms and pig liver tissue, the proposed system can achieve temperature imaging in real time, and the control steady-state error and overshoot are 0.62 °C and 0.3 % respectively. The results show that our method has the potential for accurate temperature monitoring and closed-loop temperature control during PTT.

PH-Activatable Organic Nanoparticles for Efficient Low-Temperature Photothermal Therapy of Ocular Bacterial Infection.

Low-temperature photothermal therapy (PTT) systems constructed by integrating organic photothermal agents with other bactericidal components that initiate bacterial apoptosis at low hyperthermia possess a promising prospect. However, these multicomponent low-temperature PTT nanoplatforms have drawbacks in terms of the tedious construction process, suboptimal synergy effect of diverse antibacterial therapies, and high laser dose needed, compromising their biosafety in ocular bacterial infection treatment. Herein, a mild PTT nanotherapeutic platform is formulated via the self-assembly of a pH-responsive phenothiazinium dye. These organic nanoparticles with photothermal conversion efficiency up to 84.5% necessitate only an ultralow light dose of 36 J/cm2 to achieve efficient low-temperature photothermal bacterial inhibition at pH 5.5 under 650 nm laser irradiation. In addition, this intelligent mild photothermal nanoplatform undergoes negative to positive charge reversion in acid biofilms, exhibiting good penetration and highly efficient elimination of drug-resistant E. coli biofilms under photoirradiation. Further in vivo animal tests demonstrated efficient bacterial elimination and inflammatory mitigation as well as superior biocompatibility and biosafety of the photothermal nanoparticles in ocular bacterial infection treatment. Overall, this efficient single-component mild PTT system featuring simple construction processes holds great potential for wide application and clinical transformation.

Stabilizing Enzymes in Plasmonic Silk Film for Synergistic Therapy of In Situ SERS Identified Bacteria.

Increasing antibiotic resistance becomes a serious threat to public health. Photothermal therapy (PTT) and antibacterial enzyme‐based therapy are promising nonresistant strategies for efficiently killing drug‐resistant bacteria. However, the poor thermostability of enzymes in PTT hinders their synergistic therapy. Herein, antibacterial glucose oxidase (GOx) is embedded in a Ag graphitic nanocapsule (Ag@G) arrayed silk film to fabricate a GOx‐synergistic PTT system (named silk‐GOx‐Ag@G, SGA). The SGA system can stabilize GOx by a vitrification process through the restriction of hydrogen bond and rigid β‐sheet, and keep the antibacterial activity in the hyperthermal PTT environment. Moreover, the arrayed Ag@G possesses excellent chemical stability due to the protection of graphitic shell, providing stable plasmonic effect for integrating PTT and surface enhanced Raman scattering (SERS) analysis even in the GOx‐produced H2O2 environment. With in situ SERS identification of bacterial intrinsic signals in the mouse wound model, such SGA realizes superior synergistic antibacterial effect on the infected Escherichia coli, Staphylococcus aureus, and methicillin‐resistant Staphylococcus aureus in vivo, while without causing significant biotoxicity. This system provides a therapeutic method with low resistance and in situ diagnosis capability for efficiently eliminating bacteria.

The Role of Rosmarinic Acid on the Bioproduction of Gold Nanoparticles as Part of a Photothermal Approach for Breast Cancer Treatment.

Breast cancer is a high-burden malignancy for society, whose impact boosts a continuous search for novel diagnostic and therapeutic tools. Among the recent therapeutic approaches, photothermal therapy (PTT), which causes tumor cell death by hyperthermia after being irradiated with a light source, represents a high-potential strategy. Furthermore, the effectiveness of PTT can be improved by combining near infrared (NIR) irradiation with gold nanoparticles (AuNPs) as photothermal enhancers. Herein, an alternative synthetic method using rosmarinic acid (RA) for synthesizing AuNPs is reported. The RA concentration was varied and its impact on the AuNPs physicochemical and optical features was assessed. Results showed that RA concentration plays an active role on AuNPs features, allowing the optimization of mean size and maximum absorbance peak. Moreover, the synthetic method explored here allowed us to obtain negatively charged AuNPs with sizes favoring the local particle accumulation at tumor site and maximum absorbance peaks within the NIR region. In addition, AuNPs were safe both in vitro and in vivo. In conclusion, the synthesized AuNPs present favorable properties to be applied as part of a PTT system combining AuNPs with a NIR laser for the treatment of breast cancer.

Upper-Critical-Solution-Temperature Polymer Modified Gold Nanorods for Laser Controlled Drug Release and Enhanced Anti-Tumour Therapy.

Photothermal therapy (PTT) has become effective method for the treatment of malignant cancer. The development of PTT system with high anti-tumour effect is still the feasible research direction. Here, a new type of gold nanorods (AuNRs)-doxorubicin (DOX)/mPEG10K-peptide/P(AAm-co-AN) (APP-DOX) nano drug delivery system was proposed. Among them, AuNRs was used as high-efficiency photothermal agent. APP-DOX had a suitable size and can be targeted to accumulate in tumour tissues through circulation in the body. The abundant matrix metalloproteinase 2 (MMP-2) in the tumour environment intercepted and cut off the short peptide chain structure grafted on APP-DOX. At the same time, the removal of the PEG segment leaded to an increase in the hydrophobic properties of the system. Nanoparticles aggregated into large particles, causing them to stay and aggregate further at the tumour site. When irradiated by 808 nm near-infrared laser, APP-DOX achieved a gradual heating process. High temperature can effectively ablate tumours and enable UCST polymer to achieve phase transition, resulting in more anti-cancer drugs loaded in the polymer layer DOX was released, effectively killing cancer cells. Animal experiments had verified the possibility of the nano drug-carrying system and good tumour treatment effect. What’s more worth mentioning is that compared with free DOX, the nano drug delivery system had lower biological toxicity and not cause obvious harmful effects on normal organs and tissues.

A Smart Drug Delivery System Based on Thermo-Responsive Polymer Gated Au NRs@SiO2 Nano-Platform

A key challenge for nanoparticles-based drug delivery system is to achieve manageable drug release in tumour cell. In this study, a versatile system combining photothermal therapy and controllable drug release for tumour cells using temperature-sensitive block copolymer coupled Au NRs@SiO2 is reported. While the Au NRs serve as hyperthermal agent and the mesoporous silica was used to improve the drug loading and decrease biotoxicity. The block copolymer acted as “gatekeeper” to regulate the release of model drug (Doxorubicin hydrochloride, DOX). Through in vivo and in vitro experiments, we achieved the truly controllable drug release and photothermal therapy with the collaborative effect of the three constituents of the nanocomposites. The reported nanocomposites pave the way to high-performance controllable drug release and photothermal therapy system.

NIR‐II Responsive Inorganic 2D Nanomaterials for Cancer Photothermal Therapy: Recent Advances and Future Challenges

AbstractNon‐invasive cancer photothermal therapy (PTT) is a promising replacement for traditional cancer treatments. The second near‐infrared region induced PTT (NIR‐II PTT, 1000–1500 nm) with less energy dissipation has been developed for deeper‐seated tumor treatment in recent years compared with the traditional first near‐infrared light (750–1000 nm). In addition, the use of emerging inorganic 2D nanomaterials as photothermal agents (PTAs) further enhanced PTT efficiency due to their intrinsic photothermal properties. NIR‐II light stimulated inorganic 2D nanomaterials for PTT is becoming a hot topic in both academic and clinical fields. This review summarizes the categories, structures, and photothermal conversion properties of inorganic 2D nanomaterials for the first time. The recent synergistic strategies of NIR‐II responsive PTT combined with other treatment approaches including chemotherapy, chemodynamic therapy, photodynamic therapy, radiotherapy are summarized. The future challenges and perspectives on these 2D nanomaterials for NIR‐II responsive PTT systems construction are further discussed.

“Dual lock-and-key”-controlled ceria nanotubes-based nanozymes for tumor-specific photothermal therapy

Tumor-specific activatable therapy has gained more and more attention due to its improved therapeutic efficacy and minimized side effects. However, most of these nanomedicines only utilized one stimulus as the switch of the therapeutic process, which may have the issue of low selectivity. Herein, we develop a “dual lock-and-key” type activatable nanotherapeutic platform (ABTS@PAH-CNts) for tumor-specific photothermal therapy (PTT). Such nanoplatform can only be activated under both H2O2 and acidic pH, thus achieving higher selectivity towards tumor than single stimulus-activated nanomedicine. The nanoplatform is prepared by adsorbing 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) onto the surface of ceria nanotubes. We demonstrate that ceria nanotubes have analogous peroxidase activity with natural horseradish peroxidase (HRP). Under both H2O2 and acidic pH, ceria nanotubes can catalyze ABTS into its oxidized form, showing enhanced near-infrared (NIR) absorption with good photothermal effect. ABTS@PAH-CNts shows good in vitro biocompatibility without laser irradiation, while has good anticancer efficiency under 808 nm laser irradiation. In addition, in vivo study indicates that the photothermal temperature of ABTS@PAH-CNts can reach up to 55 °C in the tumor site, while only can reach 40 °C for normal tissue, demonstrating its good tumor specificity. Our work not only develops a nanozyme-based “dual lock-and-key”-controlled PTT system, but also provides a nanoplatform for activatable theranostics.

Cationic Water-Soluble Pillar[5]arene-Modified Cu2-xSe Nanoparticles: Supramolecular Trap for ATP and Application in Targeted Photothermal Therapy in the NIR-II Window.

With the rapid progress of nanotechnology, near-infrared (NIR), light-assisted phototherapy as a minimally invasive local cancer therapy, especially photothermal therapy (PTT), has captured broad research attention in recent years. However, combined target molecules with a PTT system through reversible supramolecular interactions has been reported rarely. In this work, we constructed a supramolecular nanosystem combining ATP capture and target PTT based on cationic pillar[5]arene (CWP5)-functionalized Cu2-xSe nanoparticles (Cu2-xSe@CWP5 NPs). Cu2-xSe@CWP5 NPs, with an average diameter of approximately 100 nm and strong absorption in the near-infrared-II window, were prepared in water through a facile one-step in situ synthesis method, then (4-carboxybutyl)triphenylphosphonium bromide (TPP), a mitochondria-targeted molecule, was modified on the surface of the particles through the host-guest recognition. Upon irradiation with a 1064 nm laser, the obtained Cu2-xSe@CWP5/TPP NPs showed remarkably photothermal ablation capability to HeLa cells. Importantly, our Cu2-xSe@CWP5/TPP NPs exhibited excellent therapeutic effect due to the combination of inhibited hydrolysis of ATP and targeted photothermal therapy upon in vitro and in vivo studies. Significantly, through host-guest interactions, we can modify different types of target molecules within this PTT system at will.

Graphene Oxide Composite for Selective Recognition, Capturing, Photothermal Killing of Bacteria over Mammalian Cells.

The multifunctional photothermal therapy (PTT) platform with the ability to selectively kill bacteria over mammalian cells has received widespread attention recently. Herein, we prepared graphene oxide-amino(polyethyleneglycol) (GO-PEG-NH2) while using the hydrophobic interaction between heptadecyl end groups of 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-[amino(polyethyleneglycol)] (DSPE-PEG-NH2) and graphene oxide (GO). Based on GO-PEG-NH2, the versatile PTT system was constructed with simultaneous selective recognition, capturing, and photothermal killing of bacteria. When the cells undergo bacterial infection, owing to the poly(ethylene glycol) (PEG) chains and positively charged amino groups, GO-PEG-NH2 can specifically recognize and capture bacteria in the presence of cells. Meanwhile, the stable photothermal performance of GO-PEG-NH2 enables the captured bacteria to be efficiently photothermally ablated upon the irradiation of 808 nm laser. Besides, the GO-PEG-NH2 is highly stable in various biological media and it exhibits low cytotoxicity, suggesting that it holds great promise for biological applications. This work provides new insight into graphene-based materials as a PTT agent for the development of new therapeutic platforms.

Near infrared light-responsive heat-emitting hemoglobin hydrogels for photothermal cancer therapy.

Photothermal therapy (PTT) is an effective means of treating tumors because tumor cells are sensitive to heat. Gold and carbon nanoparticles are used as efficient PTT materials. However, development of a non-toxic biodegradable PTT agent remains a challenge. Here, we developed a hemoglobin (Hb) hydrogel that exhibited excellent PTT effects in vitro and in vivo. Unlike conventional PTT agents, which are toxic and do not decompose completely in the body, the Hb hydrogel was manufactured using only two components: (i) Hb, a natural substance derived from the human body, and (ii) PEG, an FDA-approved polymer. The gelation time of the Hb hydrogels could be controlled by changing the Hb concentration. Because Hb is present at a high concentration (150 mg/ml) in the body, the Hb hydrogel decomposed and was eliminated in vivo without toxicity. The Hb hydrogel showed an excellent PTT effect in response to 808 nm near-infrared (NIR) laser irradiation and had excellent anticancer effects against A549 lung cancer cells both in vitro and in vivo. Blood hematology and blood biochemical assay results from an animal model treated with Hb hydrogel were similar to those of the control group. Importantly, toxicity was not observed based on H&E staining of major organs (heart, liver, spleen, kidneys and lung). Tumors of A549 cell-xenografted mice treated with Hb hydrogel and 808 nm NIR laser irradiation were significantly smaller than those of the control group (23.1 mm3versus 746.5 mm3, respectively). This is a first report of a biocompatible photothermal hydrogel based on hemoglobin, and our overall results suggest that Hb hydrogels are commercially-promising PTT systems that have excellent anti-cancer effects.

Gold nanorods together with HSP inhibitor-VER-155008 micelles for colon cancer mild-temperature photothermal therapy

Enhancing the heat-sensitivity of tumor cells provides an alternative solution to maintaining the therapeutic outcome of photothermal therapy (PTT). In this study, we constructed a therapeutic system, which was composed of methoxy-polyethylene-glycol-coated-gold-nanorods (MPEG-AuNR) and VER-155008-micelles, to evaluate the effect of VER-155008 on the sensitivity of tumor cells to heat, and further investigate the therapeutic outcome of MPEG-AuNR mediated PTT combined with VER-155008- micelles. VER-155008- micelles down-regulate the expression of heat shock proteins and attenuate the heat-resistance of tumor cell. The survival of HCT116 cells treated with VER-155008- micelles under 45 °C is equal to that treated with high temperature hyperthermia (55 °C) in vitro. Furthermore, we proved either the MPEG-AuNR or VER-155008- micelles can be accumulate in the tumor site by photoacoustic imaging and fluorescent imaging. In vivo anti-cancer evaluation showed that tumor size remarkably decreased (smaller than 100 mm3 or vanished) when treated with combing 45 °C mild PTT system, which contrasted to the tumor size when treated with individual 45 °C mild PTT (around 500 nm3) or normal saline as control (larger than 2000 nm3). These results proved that the VER-155008- micelles can attenuate the heat-resistance of tumor cells and enhance the therapeutic outcome of mild-temperature photothermal therapy.

Black-Phosphorus-Incorporated Hydrogel as a Sprayable and Biodegradable Photothermal Platform for Postsurgical Treatment of Cancer.

Photothermal therapy (PTT) is a fledgling therapeutic strategy for cancer treatment with minimal invasiveness but clinical adoption has been stifled by concerns such as insufficient biodegradability of the PTT agents and lack of an efficient delivery system. Here, black phosphorus (BP) nanosheets are incorporated with a thermosensitive hydrogel [poly(d,l‐lactide)‐poly(ethylene glycol)‐poly(d,l‐lactide) (PDLLA‐PEG‐PDLLA: PLEL)] to produce a new PTT system for postoperative treatment of cancer. The BP@PLEL hydrogel exhibits excellent near infrared (NIR) photothermal performance and a rapid NIR‐induced sol–gel transition as well as good biodegradability and biocompatibility in vitro and in vivo. Based on these merits, an in vivo PTT postoperative treatment strategy is established. Under NIR irradiation, the sprayed BP@PLEL hydrogel enables rapid gelation forming a gelled membrane on wounds and offers high PTT efficacy to eliminate residual tumor tissues after tumor removal surgery. Furthermore, the good photothermal antibacterial performance prevents infection and this efficient and biodegradable PTT system is very promising in postoperative treatment of cancer.