Photothermal sensitization of amelanotic melanoma cells by Ni(II)-octabutoxy-naphthalocyanine

Incubation of B78H1 amelanotic melanoma cells with a potential photothermal sensitizer, namely, liposome-incorporated Ni(II)-octabutoxy-naphthalocyanine (NiNc), induces an appreciable cellular accumulation of the naphthalocyanine, which is dependent on both the NiNc concentration and the incubation time. No detectable decrease in cell survival occurs upon red-light irradiation (corresponding to the longest-wavelength absorption bands of NiNc) in a continuous-wave (c.w.) regime of the naphthalocyanine-loaded cells. On the other hand, 850 nm irradiation with a Q-switched Ti:sapphire laser operating in a pulsed mode (30 ns pulses, 10 Hz, 200 mJ/pulse) induces an efficient cell death. Thus, ca. 98% decrease in cell survival is obtained upon 5 min irradiation of cells that have been incubated for 48 h with 5.1 microM NiNc. The efficiency of the photoprocess is strongly influenced by the NiNc cell incubation time prior to irradiation. Photothermal sensitization with NiNc appears to open new perspectives for therapeutic applications, as suggested by preliminary in vivo studies with C57/BL6 mice bearing a subcutaneously implanted amelanotic melanoma.     

Tumour-localizing and -photosensitising properties of meso-tetra(4-nido-carboranylphenyl)porphyrin (H2TCP)

A water-soluble meso-substituted porphyrin (H(2)TCP) bearing 36 boron atoms, which appeared to be an efficient photodynamic sensitiser (singlet oxygen quantum yield=0.44), was studied for its accumulation by murine melanotic melanoma cells (B16F1). The amount of H(2)TCP in the cells increased with the porphyrin dose in the incubation medium up to, and at least, 100 microM concentrations with no significant cytotoxic effect in the dark. Moreover, the H(2)TCP uptake increased with the incubation time reaching a plateau value corresponding with the recovery of 0.4 nmol of H(2)TCP per mg of cell proteins after 24h incubation. Fluorescence microscopy observations showed that the porphyrin was largely localized intracellularly, exhibiting a discrete distribution in the cytoplasm with a pattern which was closely similar to that observed for the endosomal probe Lucifer yellow. The photosensitising efficiency of the H(2)TCP toward B16F1 cells was studied for different irradiation (1-15 min) and incubation (1-24 h) times. Nearly complete (>95%) cell mortality was obtained upon incubation with 20 microM H(2)TCP and 10 min irradiation with red light (600-700 nm, 20 mW/cm(2)). The porphyrin was also accumulated in appreciable amounts by the tumour tissue after intravenous injection to C57BL/6 mice bearing a subcutaneously transplanted melanotic melanoma. Maximum accumulation in the tumour was achieved by administration of H(2)TCP dissolved in the ternary mixture 20% dimethylsulfoxide (DMSO)-30% polyethyleneglycol (PEG 400)-50% water. Thus, this porphyrin could act as both a photodynamic therapy agent and a radiosensitising agent for boron neutron capture therapy.     

Selective photothermal therapy for mixed cancer cells using aptamer-conjugated nanorods

Safe and effective photothermal therapy depends on efficient delivery of heat for killing cells and molecular specificity for targeting cells. To address these requirements, we have designed an aptamer-based nanostructure which combines the high absorption efficiency of Au-Ag nanorods with the target specificity of molecular aptamers, a combination resulting in the development of an efficient and selective therapeutic agent for targeted cancer cell photothermal destruction. Most nanomaterials, such as gold nanoshells or nanorods (NRs), require a relatively high power of laser irradiation (1 x 10 (5)-1 x 10 (10) W/m (2)). In contrast, the high absorption characteristic of our Au-Ag NRs requires only 8.5 x 10 (4) W/m (2) laser exposure to induce 93 (+/-11)% cell death of NR-aptamer-labeled cells. Aptamers, the second component of the nanostructure, are generated from a cell-SELEX (systematic evolution of ligands by exponential enrichment) process and can be easily selected for specific recognition of individual tumor cell types without prior knowledge of the biomarkers for the cell. When tested with both cell suspensions and artificial solid tumor samples, these aptamer conjugates were shown to have excellent hyperthermia efficiency and selectivity. Under a specific laser intensity and duration of laser exposure, about 50 (+/-1)% of target (CEM) cells were severely damaged, while more than 87 (+/-1)% of control (NB-4) cells remained intact in a suspension cell mixture. These results indicate that the Au-Ag nanorod combination offers selective and efficient photothermal killing of targeted tumor cells, thus satisfying the two key challenges noted above. Consequently, for future in vivo application, it is fully anticipated that the tumor tissue will be selectively destroyed at laser energies which will not harm the surrounding normal tissue.     

A photosensitizer-loaded zinc oxide-polydopamine core-shell nanotherapeutic agent for photodynamic and photothermal synergistic therapy of cancer cells

In clinical cancer research,it is quite promising to develop multimodal synergistic therapeutic strategies.Photodynamic and photothermal synergistic therapy is a very desirable multimodal therapy strategy.Herein,we report a facile and simple method to construct a nanotherapeutic agent for photodynamic and photothermal therapy.This nanotherapeutic agent(ZnO@Ce6-PDA)is composed of a ZnO nanoparticle core,an interlayer of photosensitizer chlorin e6(Ce6)and an outer layer of polydopamine(PDA).Due to the existence of Ce6,the ZnO@Ce6-PDA can efficiently generate singlet oxygen(1O2)under 660 nm laser irradiation.Moreover,the ZnO@Ce6-PDA can serve as a photothermal agent,because of the excellent photothermal conversion efficiency of the PDA coating layer in the presence of 780 nm laser.Experiment results demonstrated that the designed nanotherapeutic agent had outstanding phototoxicity upon the combination of laser irradiation at 660 and 780 nm.Thus,our work proves that the ZnO@Ce6-PDA is a promising photodynamic/photothermal dual-modal nanotherapeutic agent for enhanced cancer therapy.     

Porphyrin-fullerene C60 dyads with high ability to form photoinduced charge-separated state as novel sensitizers for photodynamic therapy

The photodynamic activities of a porphyrin-C60 dyad (P-C60) and its metal complex with Zn(II) (ZnP-C60) were compared with 5-(4-acetamidophenyl)-10,15,20-tris(4-methoxyphenyl)porphyrin (P), both in homogeneous medium-bearing photooxidizable substrates and in vitro on the Hep-2-human-larynx-carcinoma cell line. This study represents the first evaluation of dyads, with a high capacity to form a photoinduced charge-separated state, to act as agents to inactivate cells by photodynamic therapy (PDT). Absorption and fluorescence spectroscopic studies were performed in toluene and N,N-dimethylformamide (DMF). The emission of the porphyrin moiety in the dyads is strongly quenched by the attached fullerene C60 moiety. The singlet molecular oxygen, O2(1delta(g)), productions (phi(delta)) were determined using 9,10-dimethylanthracene (DMA). The values of phi(delta) were strongly dependent on the solvent's polarity. Comparable phi(delta) values were found for dyads and P in toluene, while O2(1delta(g)) production was significantly diminished for the dyads in DMF. In more polar solvent, the stabilization of charge-transfer state takes place, decreasing the efficiency of porphyrin triplet-state formation. Also, both dyads photosensitize the decomposition of L-tryptophan in DMF. In biological medium, no dark cytotoxicity was observed using sensitizer concentrations < or = 1 microM and 24 h of incubation. The uptake of sensitizers into Hep-2 was studied using 1 microM of sensitizer and different times of incubation. Under these conditions, a value of approximately 1.5 nmol/10(6) cells was found between 4 and 24 h of incubation. The cell survival after irradiation of the cells with visible light was dependent upon light-exposure level. A higher photocytotoxic effect was observed for P-C60, which inactivates 80% of cells after 15 min of irradiation. Moreover, both dyads keep a high photoactivity even under argon atmosphere. Thus, depending on the microenvironment where the sensitizer is localized, these compounds could produce biological photodamage through either an O2(1delta(g))-mediated photoreaction process or a free-radicals mechanism under low oxygen concentration. These results show that molecular dyads, which can form a photoinduced charge-separated state, are a promising model for phototherapeutic agents, with potential applications in cell inactivation by PDT.     

Synthesis of a Near‐Infrared BODIPY Dye for Bioimaging and Photothermal Therapy

The development of robust photothermal agents for near‐infrared (NIR) imaging is a great challenge. Herein, we report the design and synthesis of a new photothermal agent, based on the aza‐boron‐dipyrromethene framework (azaBDP). This compound possessed excellent photostability and high photothermal‐conversion efficiency (50 %) under NIR laser irradiation. When the photothermal properties of this compound were utilized for tumor inhibition, stable long‐term fluorescence was observed in living animals. Photothermal treatment efficiently suppressed tumor growth, as evidenced by in vitro and in vivo experiments. Furthermore, NIR emission could be detected by using an imaging system and therapeutic self‐monitoring was achieved by using NIR imaging.     

透明质酸修饰的介孔二氧化硅包覆金纳米棒的制备及在肿瘤化疗-热疗联合治疗中的应用

通过在包覆了金纳米棒的介孔硅表面修饰生物相容性的透明质酸, 得到了具有肿瘤靶向性的多功能药物载体. 实验结果表明, 透明质酸可以通过酰胺键修饰在介孔硅表面, 所得药物载体可在透明质酸酶作用下实现选择性释放. 该体系在近红外区域具有较高的吸收, 可以在近红外光照射下实现光热转换. 细胞实验结果表明, 该多功能药物载体可以有效靶向CD44过量表达的乳腺癌细胞, 通过CD44介导的内吞富集在肿瘤内部, 结合化学药物治疗和光热治疗, 显示出更高的肿瘤细胞凋亡效率.     

Synthesis method-dependent photothermal effects of colloidal solutions of platinum nanoparticles used in photothermal anticancer therapy

One of the most common anticancer therapies is photothermal therapy (PTT). The effectiveness of PTT depends on the photosensitizer being a molecule which is toxic for the cancer cells after electromagnetic wave irradiation. Therefore, a simulation of PTT was performed in this work on two colon cancer cells (SW480 and SW620) using platinum nanoparticles (Pt NPs). Interestingly, in the literature the dependence between the synthesis method and the photothermal properties of Pt NPs was not discussed. Consequently, in this paper, we evaluated the photothermal properties of Pt NPs synthesized by two different methods: polyol (PtI NPs) and green chemistry (PtII NPs). Scanning transmission electron microscopy revealed that the size of both Pt NPs obtained was 2 nm, the NPs were not agglomerated, and that the PtII NPs were distributed on green tea supports. The selected area electron diffraction and X-ray diffraction analysis confirmed the crystallinity of both types of Pt NPs. Fourier-transform infrared (FTIR) spectrum of the PtII NPs showed interactions between the NPs and stretching modes for C=O groups from flavonoids and polyphenols. Therefore, these chemical compounds could be responsible for reducing Pt⁴⁺ ions to Pt⁰. Moreover, the 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS) assay showed that the PtII NPs exhibited 10% and 20% better cytotoxicity effect on SW480 and SW620 cells, than PtI NPs. The viability of cancer cells decreased when Pt NPs were used in PTT. The highest percentage of dead cells (82%) was observed for PtII NPs and 650-nm laser irradiation. FTIR and Raman spectroscopy showed structural changes induced by both Pt NPs and laser irradiation of cells in the range corresponding to levels of DNA, phospholipids, proteins, and lipids. Moreover, the calculated photothermal conversion efficiency showed that the value of this parameter is around 35%, regardless of the synthesis method and used wavelengths.     

Evidence for intracellular aggregation of hypericin and the impact on its photocytotoxicity in PAM 212 murine keratinocytes

We have assessed photoinduced toxicity of hypericin in PAM 212 murine keratinocytes and the relationship between concentration, incubation time and light fluence to evaluate the effect of intracellular aggregation at high concentrations. Confocal microscopy was used to establish the subcellular localization of hypericin at 5 and 50 microM and incubation times of 1 and 3 h. From fluorescence uptake time course studies, intracellular hypericin was demonstrated to exist predominantly in the monomeric form for up to 26 h incubation at 5 microM. However, there was a pronounced aggregation effect at 50 microM, with intracellular hypericin fluorescence levels initially showing an increase followed by a decrease with incubation time. This effect was subsequently shown to exert an effect on the phototoxicity of hypericin. On irradiation, the photocytotoxicity for 1 and 7 h incubation with 50 microM hypericin was comparable, whereas using 5 microM the photocytotoxicity showed good correlation with the intracellular fluorescence measurements at 1 and 7 h incubation.     

TAT peptide-functionalized gold nanostars: enhanced intracellular delivery and efficient NIR photothermal therapy using ultralow irradiance

Gold nanoparticles have great potential in plasmonic photothermal therapy (photothermolysis), but their intracellular delivery and photothermolysis efficiency have yet to be optimized. We show that TAT-peptide-functionalized gold nanostars (NS) enter cells significantly more than bare or PEGylated NS. The cellular uptake mechanism involves actin-driven lipid raft-mediated macropinocytosis, where particles primarily accumulate in macropinosomes but may also leak out into the cytoplasm. After 4-h incubation of TAT-NS on BT549 breast cancer cells, photothermolysis was accomplished using 850 nm pulsed laser under 0.2 W/cm(2) irradiation, below the maximal permissible exposure of skin. These results demonstrate the enhanced intracellular delivery and efficient photothermolysis of TAT-NS, promising agents in cancer therapy.     

Influence of polymer molecular weight on the chemical modifications induced by UV laser ablation

This paper investigates the influence of polymer molecular weight (M(W)) on the chemical modifications of poly(methyl methacrylate), PMMA, and polystyrene, PS, films doped with iodonaphthalene (NapI) and iodophenanthrene (PhenI), following irradiation at 248 nm (KrF excimer laser, 20 ns fwhm and hybrid excimer-dye laser, 500 fs fwhm) and at 308 nm (XeCl excimer laser, 30 ns fwhm). The changes of intensity and position of the polymer Raman bands upon irradiation provide information on cleavage of the polymer bonds. Degradation of PMMA, which is a weak absorbing system at 248 nm, occurs to a higher extent in the case of a larger M(W), giving rise to the creation of unsaturation centers and to degradation products. For highly absorbing PS, no degradation is observed upon irradiation with a KrF laser. Consistently irradiating doped PS at 308 nm, where the absorption is low, induces degradation of the polymer. Results provide direct support for the bulk photothermal model, according to which ejection requires a critical number of broken bonds. In the case of irradiation of doped PMMA with pulses of 248 nm and 500 fs, neither degradation nor dependence with polymer M(W) are observed, indicating that mechanisms involved in the femtosecond laser ablation differ from those operating in the case of nanosecond laser ablation. Participation of multiphoton/avalanche processes is proposed.     

A Photoinduced Nonadiabatic Decay‐Guided Molecular Motor Triggers Effective Photothermal Conversion for Cancer Therapy

It remains highly challenging to identify small molecule‐based photothermal agents with a high photothermal conversion efficiency (PTCE). Herein, we adopt a double bond‐based molecular motor concept to develop a new class of small photothermal agents to break the current design bottleneck. As the double‐bond is twisted by strong twisted intramolecular charge transfer (TICT) upon irradiation, the excited agents can deactivate non‐radiatively through the conical intersection (CI) of internal conversion, which is called photoinduced nonadiabatic decay. Such agents possess a high PTCE of 90.0 %, facilitating low‐temperature photothermal therapy in the presence of a heat shock protein 70 inhibitor. In addition, the behavior and mechanism of NIR laser‐triggered molecular motions for generating heat through the CI pathway have been further understood through theoretical and experimental evidence, providing a design principle for highly efficient photothermal and photoacoustic agents.     

Ag@TiO2 Nanoprisms with Highly Efficient Near‐Infrared Photothermal Conversion for Melanoma Therapy

Melanoma is a primary reason of death from skin cancer and associated with high lethality. Photothermal therapy (PTT) has been developed into a powerful cancer treatment technique in recent years. Here, we created a low‐cost and high‐performance PTT agent, Ag@TiO₂ NPs, which possesses a high photothermal conversion efficiency of ≈65 % and strong near‐infrared (NIR) absorption about 808 nm. Ag NPs were synthesized using a two‐step method and coated with TiO₂ to obtain Ag@TiO₂ NPs by a facile sol‐gel method. Because of the oxide, Ag@TiO₂ NPs exhibit remarkable high photothermal conversion efficiencies and biocompatibility in vivo and in vitro. Cytotoxicity and therapeutic efficiency of photothermal cytotoxicity of Ag@TiO₂ NPs were tested in B16‐F10 cells and C57BL/6J mice. Under light irradiation, the elevated temperature causes cell death in Ag NPs‐treated (100 μg mL^?1) cells in vitro (both p<0.01). In the case of subcutaneous melanoma tumor model, Ag@TiO₂ NPs (100 μg mL^?1) were injected into the tumor and irradiated with a 808 nm laser of 2 W cm^?2 for 1 minute. As a consequence, the tumor volume gradually decreased by NIR laser irradiation with only a single treatment. The results demonstrate that Ag@TiO₂ NPs are biocompatible and an attractive photothermal agent for cutaneous melanoma by local delivery.     

Biological effects of helium-neon (HeNe) laser irradiation on acrosome reaction in bull sperm cells

The purpose of this study was to determine the effect of He---Ne laser irradiation (632.8 nm, 10 mW) on the induction of acrosome reaction and mortality in bull sperm cells in comparison with two important capacitation agents; calcium and heparin. Frozen-thawed bull sperm cells were washed in percoll gradient and suspended at a concentration of 1 × 10⁶ ml⁻¹ in sp-TALP medium, capacitated in the presence of 2 mM CaCl₂, 10 μg ml⁻¹ heparin, or irradiated at fluences from 2 to 16 J cm⁻², and incubated for 0, 30, 60 and 90 minutes. At the end of the incubation period, the percentage of sperm that were acrosome-reacted and dead was determined. The results obtained indicated that laser irradiation at all fluences produced a significant increase (p < 0.001) in the percentage of sperm cells that were acrosome reacted, and a significant decrease (p < 0.001) in the percentage of dead sperm at 90 minutes of incubation in comparison to other capacitation agents and the control group. The percentage of sperm cells with acrosome reaction was increased with increasing fluences of laser irradiation and time of incubation. It is conclude that the application of He---Ne laser irradiation at fluences from 2 to 16 J cm⁻² induced the acrosome reaction and decreased the sperm mortality percentage in vitro of bull sperm cells.     

In vitro PHOTOSENSITIZING PROPERTIES OF RHODAMINE 123 ON DIFFERENT HUMAN TUMOR CELL LINES

Abstract— In this study, human tumor cell lines of different origin (colon carcinoma HT29, breast carcinoma MCF7 and malignant melanoma M14) were incubated for 24 h at 37*deg;C with Rhodamine 123 (Rh123) at concentrations ranging up to 4 μg/ml;. Immediately after drug removal, light irradiation was delivered at 500 W/m² for 5 min using an argon laser. After irradiation, viable cells were counted and assayed for colony formation. When only Rh123 was administered, a 50% survival was obtained at about 2.77 μg/ml and 1.48 μg/ml; for HT29 and MCF7, respectively. After light irradiation, 50% survival doses decreased to 0.47 μg/ml and 0.18 μg/ml for the two carcinoma cell lines, respectively. In the case of malignant melanoma, the decrease in survival was relatively lower than those obtained with carcinoma cells: 50% survival dose was 3.54 μg/ml with Rh123 alone and 1.32 μ/ml after irradiation. The lower sensitivity of M14 melanoma cells seems to be related to different uptake and release of drug by these cells with respect to carcinoma lines.     

Induction of phr gene expression in E. coli strain KY706/pPL-1 by He-Ne laser (632.8 nm) irradiation

We have observed that He–Ne laser irradiation of E. coli strain KY706/pPL-1 leads to induction of photolyase gene, phr. The magnitude of induction was found to depend on the He–Ne laser fluence, fluence rate and post-irradiation incubation period in the nutrient medium. The optimum values for fluence and fluence rate were 7×10³ J/m² and 100 W/m², respectively, and the induction of phr gene was observed to saturate beyond an incubation period of 2 h. Experiments carried out with singlet oxygen quenchers and with D₂O suggest that the effect is mediated via singlet oxygen. Photoreactivation studies carried out after UVC exposure of both the He–Ne laser-exposed as well as unexposed cells showed a larger surviving fraction in the He–Ne laser pre-irradiated cells. This can be attributed to He–Ne laser irradiation-induced induction of phr expression. However, since even without photoreactivating light He–Ne laser pre-irradiated cells show higher survival against UVC radiation it appears that He–Ne laser irradiation induces both light-dependent as well as dark DNA repair processes.     

Bovine Serum Albumin Nanospheres Synchronously Encapsulating “Gold Selenium/Gold” Nanoparticles and Photosensitizer for High-Efficiency Cancer Phototherapy

Gold nanostructures have generated significant attention in biomedical areas because of their major role in cancer photothermal therapeutics. In order to conveniently combine gold nanostructures and drugs into one nanocomposite, Au₂Se/Au core–shell nanostructures with strong near-infrared-absorbing properties were synthesized using a simple method and embedded inside bovine serum albumin (BSA) nanospheres by using a spray dryer equipped with an ultrasonic atomizer followed by thermal denaturation. The nanospheres with narrow size distribution mainly ranging from 450 to 600 nm were obtained. The Au₂Se/Au-loaded BSA nanospheres (1 mg) adsorbed at least 0.01 mg of water-insoluble zinc phthalocyanine (ZnPc) photosensitizer. After irradiation with a 655-nm laser (20 min), the temperature of the Au₂Se/Au-loaded BSA nanospheres [200 μL, 2 mg/mL, BSA/Au₂Se/Au 10:1 (w/w)] increased by over 20 °C from the initial temperature of 24.82?±?0.15 °C, and the release of ZnPc was improved compared with a corresponding sample without irradiation. After being incubated with cancer cells (human esophageal carcinoma Eca-109), the nanospheres exhibited photothermal and photodynamic therapy with a synergistic effect upon laser irradiation. This work provides novel Au₂Se/Au-loaded polymer nanospheres prepared by a high-efficiency strategy for incorporating drugs for improving the efficiency in killing cancer cells.     

TiO2 Nanotubes as a Therapeutic Agent for Cancer Thermotherapy

We report the photothermal properties as well as the in vitro cell test results of titanium oxide nanotubes (TiO₂ NTs) as a potential therapeutic agent for cancer thermotherapy in combination with near-infrared (NIR) light. TiO₂ NTs are found to have a higher photothermal effect upon exposure to NIR laser than Au nanoparticles and single-wall carbon nanotubes, which have also attracted considerable interest as therapeutic agents for cancer thermotherapy. The temperature increase of a TiO₂ NT/NaCl suspension during NIR laser exposure is larger than that of a TiO₂ NT/D.I. water suspension due to the heat generated by the formation of Na₂TiF_6. According to the in vitro cell test results the cells exposed to NIR laser without TiO₂ NT treatment have a cell viability of 96.4%. Likewise, the cells treated with TiO₂ NTs but not with NIR irradiation also have a cell viability of 98.2%. Combination of these two techniques, however, shows a cell viability of 1.35%. Also, the cell deaths are mostly due to necrosis but partly due to late apoptosis. These results suggest that TiO₂ NTs can be used effectively as therapeutic agents for cancer thermotherapy due to their excellent photothermal properties and high biocompatibility.     

聚多巴胺修饰金纳米花的可控制备及在光热治疗中的应用

采用无模板法制备了金纳米花, 其形状与粒径大小可以通过改变反应温度和还原剂抗坏血酸的用量来调控; 然后, 通过多巴胺的表面原位聚合反应制备了聚多巴胺修饰的金纳米花, 以提高其在近红外区的吸收能力及生物相容性. 采用透射电子显微镜(TEM)、 紫外-可见吸收光谱(UV-Vis)和纳米粒度/Zeta电位仪等对金纳米花和聚多巴胺修饰金纳米花的形态、 粒径和光学特性进行了表征; 通过傅里叶变换红外吸收光谱(FTIR)分析证明聚多巴胺修饰成功; X射线衍射(XRD)分析结果表明, 聚多巴胺修饰前后金纳米花的晶体结构未变; 最后, 采用噻唑蓝(MTT)法体外评价了聚多巴胺修饰金纳米花的细胞毒性. 研究结果表明, 反应温度越低, 金纳米花表面分支结构越丰富, 以0 ℃为最佳反应温度; 还原剂抗血酸的用量越高, 金纳米花粒径越小; 金纳米花粒径在60~100 nm范围内可调, 最大吸收波长为575~650 nm. 经聚多巴胺修饰后, 金纳米花的最大吸收波长发生了显著红移(>80 nm), 近红外区的吸收范围显著扩大. 通过调控多巴胺溶液浓度, 可将金纳米花表面聚多巴胺层的厚度控制在8~14 nm. 在808 nm激光辐照下, 聚多巴胺修饰金纳米花溶液可迅速升温至57 ℃. 此外, 细胞实验结果表明, 聚多巴胺修饰后金纳米花的细胞毒性更低. 用其对HeLa肿瘤细胞进行光热治疗后, 细胞存活率仅为10%. 因此, 聚多巴胺修饰金纳米花作为光热试剂在肿瘤治疗领域具有潜在的应用前景.