Glutathione-Mediated Clearable Nanoparticles Based on Ultrasmall Gd2O3 for MSOT/CT/MR Imaging Guided Photothermal/Radio Combination Cancer Therapy.

Recently, multifunctional clearable inorganic theranostic nanoparticles have been attracting more and more attention. Protein-based nanoparticles can be cleared by the hepatobiliary system efficiently. In this work, ultrasmall gadolinium oxide (Gd2O3) nanoparticles, which possess the advantage of high longitudinal relaxation rate, were coated with bovine serum albumin (BSA). After the Gd2O3/BSA nanoparticles were linked with two-dimensional photothermal MoS2 nanomaterials, the nanoparticles were also modified with hyaluronic acid (HA) through the disulfide bonds for tumor-targeting effect. As indicated by in vitro and in vivo studies, these Gd2O3/BSA@MoS2-HA nanoparticles could be rapidly degraded and excreted after reacting with glutathione (GSH) by the redox response, thus avoiding long-term toxicity. In addition, the cellular uptake study and in vivo multispectral optoacoustic tomography (MSOT), X-ray computed tomography (CT), and magnetic resonance (MR) triple-modal images demonstrated that Gd2O3/BSA@MoS2-HA nanoparticles exhibited a high tumor uptake effect after intravenous injection. Consequently, such clearable theranostic nanoparticles with multiple functions, which are applicable in multimodal imaging-guided cancer therapy, might show promise for applications in nanomedical science.

One-Pot Synthesis of a Bismuth Selenide Hexagon Nanodish Complex for Multimodal Imaging-Guided Combined Antitumor Phototherapy.

For integrating therapy and diagnosis into a single nanoparticle for higher antitumor efficiency and lower toxicity, our group designed a smart theranostic nanoplatform based on a hyaluronic acid-doped polypyrrole-coated bismuth selenide loading with a zinc phthalocyanine nanodish complex (Bi2Se3@HA-doped PPy/ZnPc) for multimodal imaging-guided combined phototherapy. Moreover, we expect that the HA-doped PPy smart shell for the surface functionalization will also be applied to a variety of 2D nanomaterials sharing a similar structure with Bi2Se3 to broaden their applications in biomedicine. The Bi2Se3 hexagon nanodish was synthesized via a simple and safe solution-based method compared to the commonly adopted ones. A one-pot synthesis of the naoncomplex was carried out by adding HA during the polypyrrole coating on the Bi2Se3 process, and then it was further loaded with ZnPc. Besides the good ability for infrared thermal, photoacoustic, fluorescence, and X-ray computed tomography imaging, the nanodish complex has its own high photoheat conversion efficiency for photothermal therapy, and it has remarkable optical absorption of the coefficient for photodynamic therapy. With the EPR effect of nanoparticles and the CD44-targeted effect of HA, the tumor-growth inhibition ratio of Bi2Se3@HA-doped PPy/ZnPc for PTT/PDT was as high as 96.4%, compared with that of the PTT (68.0%) or PDT (24.3%) alone, showing an excellent combined therapeutic effect. Moreover, no obvious toxicity in vivo was caused by the nanoparticles. Thus, such a Bi2Se3@HA-doped PPy/ZnPc nanodish complex has promise for real-time monitoring and precise, high-efficiency antitumor treatment.

Targeted lipid-polyaniline hybrid nanoparticles for photoacoustic imaging guided photothermal therapy of cancer.

Designing a targeted and versatile photothermal agent for the integration of precise diagnosis and effective photothermal treatment of tumors is desirable but remains a great challenge. In this study, folic acid ligand conjugated lipid-coated polyaniline hybrid nanoparticles (FA-Lipid-PANI NPs) were successfully fabricated by a distinctive technology. The obtained hybrid FA-Lipid-PANI NPs with small size exhibited not only significant photoacoustic (PA) imaging signals, but also a remarkable photothermal effect for tumor treatment. With PA imaging and photothermal therapy (PTT), the tumor could be accurately positioned and thoroughly eradicated in vivo after intravenous injection of FA-Lipid-PANI NPs. These multifunctional nanoparticles could play an important role in simultaneously facilitating imaging and PTT to achieve better therapeutic efficacy.

Different relationships between central dopamine system and sub-processes of inhibition: Spontaneous eye blink rate relates with N2 but not P3 in a Go/Nogo task.

Clinical studies show that dysfunction of the dopamine (DA) system could differently modulate N2 and P3 components in a Go/Nogo task, a classical inhibition task. However, results of previous clinical studies cannot be arbitrarily generalized to healthy adults. Thus, the present exploratory study aimed to investigate whether there are significant and variable relationships between individual differences of the DA system in normal healthy persons and N2- and P3-related sub-processes of inhibition in a Go/Nogo task. DA function was measured by spontaneous eye blink rate (EBR), which is an effective clinical and non-invasive measure and strongly related to the activity of the central dopaminergic system. A total of 28 young adults participated in this experiment. Results showed that Nogo-N2 and Nogo-P3 of all participants were larger than Go-N2 and Go-P3, while Nogo-N2 and Nogo-P3 were significantly related with Nogo-accuracy. Moreover, it was shown that higher EBRs were significantly correlated with larger and more negative N2 amplitudes under Go- and Nogo-conditions; however, there were no significant correlations between participants' EBRs and N2 latencies, and between EBRs and average amplitudes of P3 under the two conditions. Based on these results, we concluded that the central DA system was associated with the N2-related conflict monitoring rather than P3-related sub-process of inhibition.

Skin targeted lipid vesicles as novel nano-carrier of ketoconazole: characterization, in vitro and in vivo evaluation.

Liposomal carriers for topical drug delivery have been studied since the 1980s and have evoked a considerable interest. However, the conventional liposomes do not deeply penetrate into the skin and remain confined to the outer layer of SC. In order to increase skin targeting of ketoconazole (KCZ), a hydrophobic broad-spectrum antifungal agent, this study describes novel lipid vesicles as nano-carriers for topical delivery. In this paper, lipid vesicular systems including conventional liposomes (CL), ethosomes, deformable liposomes (DL) and ethanol-containing deformable liposomes (DEL) were prepared as nano-carriers for KCZ, respectively. Sodium dodecyl sulfate [SDS, 0.08 % (W/V)] was used as edge activator for DL and DEL preparation. Characterization of the vesicles was based on particle size, zeta potential, entrapment efficiency and transmission electron microscopy (TEM). In addition, in vitro permeation profile was obtained using vertical diffusion Franz cells by porcine skin. The in vivo accumulation of KCZ was also evaluated in rat skin. Confocal microscopy was performed to visualize the penetration of fluorescently labeled vesicles into skin. All of the lipid vesicles showed almost spherical structures with low polydispersity index (PDI < 0.3) and nano-metric size (no more than 160 nm). The results demonstrated that DEL dramatically improved both in vitro and in vivo skin deposition compared to the CLs (P < 0.05), which was further confirmed by confocal laser scanning microscopy study. In vivo pharmacodynamic studies showed DEL improved antifungal activity against Candida albicans in shorter duration of time. Therefore, based on present study, the novel nano-carrier DEL capable of enhancing skin target effect and forming a micro drug-depot could serve as an effective skin targeting delivery for KCZ as an anti-fungal agent in local therapy.

Development of nanovesicular systems for dermal imiquimod delivery: physicochemical characterization and in vitro/in vivo evaluation.

The aim of the current investigation was to develop and statistically evaluate nanovesicular systems for dermal imiquimod delivery. To this purpose, transethosomes were prepared with phospholipid, ethanol and different permeation enhancers. Conventional ethosomes, with soy phospholipid and ethanol, were used as control. The prepared vesicles were characterized for size, zeta potential, stability and entrapment efficiency. The optimal transethosomal formulation with mean particle size of 82.3 ± 9.5 nm showed the higher entrapment efficiency (68.69 ± 1.7%). In vitro studies, permeation results of accumulated drug and local accumulation efficiency were significantly higher for transethosomes (24.64 µg/cm(2) and 6.70, respectively) than control (14.45 µg/cm(2) and 3.93, respectively). Confocal laser scanning microscopy of rhodamine 6G-loaded transethosomes revealed an enhanced retention into the deeper skin layers as compared to conventional ethosomes. Besides, Fourier-transform infra-red spectroscopy studies were also performed to understand the mechanism of interaction between skin and carriers. What's more, results of in vivo studies indicated the transethosomes of imiquimod providing the most effectiveness for dermal delivery among all of the formulations. These results suggested that transethosomes would be a promising dermal carrier for imiquimod in actinic keratose treatment.

A novel topical targeting system of caffeine microemulsion for inhibiting UVB-induced skin tumor: characterization, optimization, and evaluation.

The purpose of the present study was to develop an optimal microemulsion (ME) formulation as topical nanocarrier of caffeine (CAF) to enhance CAF skin retention and subsequently improve its therapeutic effect on UVB-induced skin carcinogenesis. The pseudo-ternary phase diagram was developed composing of Labrafil M 1944 CS as oil phase, Cremophor EL as surfactant, tetraglycol as cosurfactant, and water. Four ME formulations at water content of 50, 60, 70, and 80% were prepared along the water dilution line of oil to surfactant ratio of 1:3 and characterized in terms of morphology, droplet size, and electric conductivity. A gel at the same drug loads (1%, w/w) was used as control. Ex vivo skin permeation studies were conducted for ME optimization. The optimized formulation (ME4) was composed of 5% (w/w) Labrafil M 1944 CS, 15% (w/w) Smix (2/1, Cremophor EL and tetraglycol), and 80% (w/w) aqueous phase. The skin location amount of CAF from ME4 was nearly 3-fold higher than control (P < 0.05) with improved permeated amount through the skin. The skin targeting localization of hydrophilic substance from ME4 was further visualized through fluorescent-labeled ME by a confocal laser scanning microscope. In pharmacodynamics studies, CAF-loaded ME4 was superior in terms of increasing apoptotic sunburn cells (P < 0.05) as compared with control. Overall results suggested that the ME4 might be a promising vehicle for the topical delivery of CAF.

Effect of hydroxyl groups and rigid structure in 1,4-cyclohexanediol on percutaneous absorption of metronidazole.

In a previous study, a synergistic retardation effect of 1,4-cyclohexanediol and 1,2-hexanediol on percutaneous absorption and penetration of metronidazole (MTZ) was discovered. A complex formation between 1,4-cyclohexanediol and 1,2-hexanediol was proposed to be responsible for the observed effect. The objective of this study was to investigate the necessity of hydroxyl group and the ring structure in 1,4-cyclohexanediol on percutaneous absorption and penetration of MTZ. Eleven formulations were studied in an in vitro porcine skin model using glass vertical Frans Diffusion Cell. 1,4-Cyclohexanediol was changed into 1,4-cyclohexanedicarboxylic acid, trans (and cis)-1,2-cyclohexanediol and 1,6-hexanediol, respectively, to study if H-bonding or ring structure would influence the retardation effect. MTZ was applied at infinite dose (100 mg), which corresponded to 750 µg of MTZ. Based on modifier ratios (MR) calculated by the flux values, the retardation effect on percutaneous absorption and penetration of MTZ was found in the formulations containing 1,4-cyclohexanedicarboxylic acid or cis-1,2-cyclohexanediol (MR values were 0.47 for which only contains 1,4-cyclohexanedicarboxylic acid, 0.74 for the formulation containing both 1,4-cyclohexanedicarboxylic acid and 1,2-hexanediol, and 0.90 for the formulation containing cis-1,2-cyclohexanediol and 1,2-hexanediol, respectively). The results showed that the hydroxyl group and structure of 1,4-cyclohexanediol played a significant role in retardation effects and provided valuable insight on the mechanisms of retardation effect through structure-activity relationships.

Effect of hydrocarbon chain length in 1,2-alkanediols on percutaneous absorption of metronidazole: toward development of a general vehicle for controlled release.

The objective of the present study is to investigate the effect of hydrocarbon chain length in 1,2-alkanediols on percutaneous absorption of metronidazole (MTZ). Twelve formulations (1,2-propanediol, 1,2-butanediol, 1,2-pentanediol, 1,2-hexanediol in 4% concentration, 1,2-hexanediol, and 1,2-heptanediol in 1% concentration, in the absence and presence of 1,4-cyclohexanediol, respectively) were studied in an in vitro hairless mouse skin model using Franz diffusion cell. Based on the flux values and retardation ratios (RR), a penetration retardation effect on percutaneous absorption of MTZ was observed for the formulations containing 1,2-diols having six- to seven-carbon chain in the presence of 1,4-cyclohexanediol (1,2-hexanediol with chain length of six hydrocarbons, RRs are 0.69 and 0.76 in the concentration of 4% and 1%, respectively; 1,2-heptanediol with chain length of seven hydrocarbons, RR is 0.78 in the concentration of 1%). On the other hand, no retardation effect was observed in formulations containing short alkyl chains (RRs of 1,2-propanediol, 1,2-butanediol, and 1,2-pentanediol are 0.99, 1.61, and 0.96, respectively). Instead, a penetration enhancement effect was observed for 1,2-diols having four and five carbons. In other words, effect of 1,2-alkanediols on percutaneous absorption of MTZ can be systematically modulated by simply varying number of -CH2 groups in the hydrocarbon chain-from being a penetration enhancer to retardant. These observations shed light on mechanism of the penetration enhancement and retardation effect and provide insight into rational design of penetration enhancers and retardants. Furthermore, the combination of 1,2-alkanediols and 1,4-cyclohexanediol could become a general vehicle for controlled release of pharmaceutical and cosmetic active ingredients.

Effect of ionization and vehicle on skin absorption and penetration of azelaic acid.

OBJECTIVE: The aim of this study is to investigate the effect of ionization and vehicle of topical formulations on skin absorption and penetration of azelaic acid (AZA). MATERIALS AND METHODS: In vitro transport of AZA was determined for two topical formulations containing AZA with pH values of 3.9 and 4.9, respectively. FINACEA(®) (15% AZA gel), a US Food and Drug Administration approved drug for treatment of acne and rosacea, was also used for comparison. Release profile and flux of AZA were determined in an in vitro hairless mouse skin model using Franz Diffusion Cell. RESULTS: The data have shown that a higher concentration of AZA is retained in the epidermis/dermis layer and the whole skin for the formulation with pH = 4.9 as compared to that with pH = 3.9 at an active loading level of 2.82 mg/cm(2). In addition, the flux of ionized species of AZA in the pH 4.9 formulation (128.4 ± 35.9 µg/cm(2)/h) is approximately five-fold greater than that in the pH 3.9 formulation (27.7 ± 4.0 µg/cm(2)/h). The results suggest that the ionized AZA penetrates through the skin and accounts for majority of the total flux. DISCUSSION AND CONCLUSION: This study has demonstrated that the penetration and absorption of AZA show a strong pH- and vehicle-dependency. Solubilization is the rate-limiting step in percutaneous absorption of AZA.

Microemulsion: a novel transdermal delivery system to facilitate skin penetration of indomethacin.

In this study, we aimed to develop thermodynamically stable microemulsion formulations of indomethacin with lower surfactant and cosurfactant contents, to improve drug permeability. Formulations were based on the oil/water microemulsion region of pseudo-ternary phase diagrams. The characteristic parameters (viscosity, diameter, and polydispersity) of the microemulsion formulations were then determined. In vitro permeation studies were performed using Franz diffusion cells. Permeation through mouse skin and skin retention of indomethacin microemulsions and ointment were tested. The cumulative amount of permeated indomethacin and its skin retention were significantly higher in microemulsion formulations compared with ointment. Drug flux and skin retention improved with decreasing droplet diameter of the microemulsions. On the basis of these results, we suggest some possible mechanisms for the enhanced transdermal permeation of drugs in microemulsions, including high drug-loading capacity, permeation enhancement by surfactants and cosurfactants, and smaller droplet diameter. In conclusion, microemulsions represent a novel transdermal delivery vehicle for increasing the solubility and permeability of indomethacin.

Assessment of the percutaneous penetration of indomethacin from soybean oil microemulsion: effects of the HLB value of mixed surfactants.

The objective of this study was to evaluate the influence of the ratios or the hydrophile-lipophile balance (HLB) values of Cremophor EL and Span 80 on the phase behavior of the O/W microemulsions and the percutaneous absorption and penetration of indomethacin microemulsions. The existence of microemulsion regions is investigated in quaternary systems composed of soybean oil/Cremophor EL and Span 80 (mixed surfactants)/diethylene glycol monoethyl ether (cosurfactant)/water by constructing pseudo-ternary phase diagrams at various Cremophor EL/Span 80 ratios. In addition, five microemulsion formulations with various mixed surfactants HLB values were evaluated by in vitro penetration experiments using mouse skin and Franz diffusion cells. The flux and amount of indomethacin penetration from 5 microemulsion formulations were significantly different from the control, and the enhance ratios ranged from 2.38 to 4.68 and 2.11 to 4.23, respectively. The HLB value of mixed surfactants in the formulations was a principal factor in determining the percutaneous penetration of the drug. The flux and amount of drug penetration increased gradually with increasing content of the lipophilic surfactant Span 80 and skin retention was highest for mixed surfactants with a HLB value of 7.6. Therefore, it is suggested that the presence of mixed surfactants was beneficial in the formation of O/W microemulsions and enhanced percutaneous penetration of indomethacin.

Chitosan microparticles for oral bioavailability improvement of the hydrophobic drug curcumin.

The aim of this study was to assess the feasibility of microparticles for dissolution enhancement and oral bioavailability of curcumin (Cur). Microparticles were prepared by the ionic crosslinking interaction with the use of tripolyphosphate (TPP) and chitosan (Cs). The physicochemical characteristics of microparticles were investigated. The in vivo performance was assessed by a pharmacokinetic study. The microparticles had an average diameter of 58.50 microm. Acceptable drug loading and encapsulation efficiency of microparticles were obtained to be 33.5% and 85.2%, respectively. Dissolution of Cur enhanced in the microparticles in comparison with pure drug. Drug release profile of Cur from microparticles fitted the first-order model. Microparticles provided improved pharmacokinetic parameters (Cmax 270.24 ng/ml, T(max) 1.30 h) in rats as compared with pure drug (C(max) 87.06 nglml, Tmax 0.66 h). The AUC value of microparticles was 8.4 fold that of the pure drug. The information from this study suggests that the developed microparticles successfully enhanced dissolution of the poorly water-soluble drug Cur, and eventually, improved its oral bioavailability effectively.

Improved bioavailability of poorly water-soluble drug curcumin in cellulose acetate solid dispersion.

Curcumin (Cur), one of the most widely used natural active constituents with a great variety of beneficial biological and pharmacological activities, is a practically water-insoluble substance with a short biologic half-life. The aim of this study was to develop a sustained-release solid dispersion by employing water-insoluble carrier cellulose acetate for solubility enhancement, release control, and oral bioavailability improvement of Cur. Solid dispersions were characterized by solubility, in vitro drug release, Fourier transform infrared spectroscopy, X-ray diffractometry, and differential scanning calorimetry studies. The in vivo performance was assessed by a pharmacokinetic study. Solid-state characterization techniques revealed the amorphous nature of Cur in solid dispersions. Solubility/dissolution of Cur was enhanced in the formulations in comparison with pure drug. Sustained-release profiles of Cur from the solid dispersions were ideally controlled in vitro up to 12 h. The optimized formulation provided an improved pharmacokinetic parameter (C(max) = 187.03 ng/ml, t(max) = 1.95 h) in rats as compared with pure drug (C(max) = 87.06 ng/ml, t(max) = 0.66 h). The information from this study suggests that the developed solid dispersions successfully enhanced the solubility and sustained release of poorly water-soluble drug Cur, thus improving its oral bioavailability effectively.

S-nitrosothiols loaded mini-sized Au@silica nanorod elicits collagen depletion and mitochondrial damage in solid tumor treatment.

To a large extent, the dense extracellular matrix (ECM), which tightly connects tumor cells to arm the tumor into an intractable fortress, significantly decreases the nanoparticles delivery efficacy and overall performance in cancer treatments. Therefore, it is necessary to transform the dense stroma of solid tumors to loose state, which could realize deep penetration of nanomedicine and enhance cancer treatment effects. Here, we fabricated a protein-free collagen nanosweeper, triphenylphosphonium bromide (TPP) coated and S-nitrosothiols loaded mini-sized Au@silica nanorod (Au@SiO2-SNO/PEG/TPP, GSNP-TPP), to clear the transport barriers of nanoparticles as well as elevate enhanced permeability and retention (EPR) effect, thus alleviating the diffusion resistance and realizing further penetration of nanoparticles. Methods: By modifying the Au@silica with thermo-sensitive S-nitrosothiols, the carrier could release the nitric oxide (NO) due to the surface overheat as well as perform photothermal therapy (PTT) under near-infrared (NIR) laser irradiation. The level of collagen depletion was observed via western blotting and immunofluorescent staining. In addition, the dual-imaging and antitumor efficiency of GSNP-TPPs were evaluated with the HeLa tumor-bearing mouse model. Results: On one hand, the released NO could deplete collagen by activating matrix metalloproteinases (MMPs) to break collagen fibers, thus loosening the dense ECM to enhance the cellular internalization. On the other hand, with the mitochondrial-targeted effect of TPP, the diffusible NO in tumor might rapidly interact with superoxide anion (O2Y-) to produce highly toxic and powerful reactive nitrogen species (RNS) -- peroxynitrite (ONOO-), which resulted in mitochondrial damage to induce cell apoptosis. With the unique properties of mini-sized gold nanorods, the formulated nanoparticles exhibited good computed tomography (CT) and multi-spectral optoacoustic tomography (MSOT) imaging effects in precisely locating and monitoring tumor. Moreover, the antitumor efficacy of GSNP-TPPs + laser group was further confirmed by ex-vivo histological analysis of tumor tissue. Conclusion: This work points out a strategy to overcome the obstacle standing in nanoparticles penetration, and opens the door of further exploitation of NO-related theranostic systems.

Ultra-small Bi2S3 nanodot-doped reversible Fe(ii/iii)-based hollow mesoporous Prussian blue nanocubes for amplified tumor oxidative stress-augmented photo-/radiotherapy.

Improving the generation of reactive oxygen species (ROS) while consuming glutathione (GSH) is the main method for amplifying intracellular oxidative stress. However, in previous studies, it was normally necessary to combine two or more materials to achieve the effect of destroying the intracellular redox homeostasis. This made the preparation process relatively complicated. Herein, we designed ultra-small bismuth sulfide quantum dot (Bi2S3 QD)-doped hollow mesoporous Prussian blue (HMPB) (HMPB/Bi2S3) nanocubes for amplified tumor oxidative stress to augment photo-/radiotherapy. In addition to being photothermal materials, Prussian blue can be used as both a catalyst for the Fenton reaction and a consumer of GSH due to the multivalent state of iron. Ferrous ions (Fe(ii)) can produce toxic ROS-hydroxyl radicals (˙OH) with abundant hydrogen peroxide in the tumor cells by the Fenton reaction. Meanwhile, ferric ions (Fe(iii)) can oxidize the intracellular GSH to GSSG, thus depleting the concentration of GSH inside tumors. As a result, oxidative stress imbalance could be induced by the reversible redox property of Fe(ii/iii), thereby causing DNA damage and increasing the cell membrane permeability to realize enhanced photo-/radiotherapy. As a sensitizer for radiotherapy, ultra-small Bi2S3 QDs (3-5 nm) are doped in HMPB, thus improving the therapeutic effect by prolonging blood circulation and reducing systemic toxicity via kidney metabolism. Therefore, such a reversible HMPB/Bi2S3 nanocube is a promising therapeutic agent for amplified tumor oxidative stress to augment photo-/radiotherapy, which might show further applications in nanomedical science.

Boosted photocatalytic activity induced NAMPT-Regulating therapy based on elemental bismuth-humic acids heterojunction for inhibiting tumor proliferation/migration/inflammation.

Due to the highly complex biological formation procedure, tumor is still difficult to be treated efficiently and always associated with proliferation, migration and inflammation during treatment. Herein, a novel strategy of boosted photocatalytic activity induced NAMPT-regulating therapy is used for tumors inhibition based on FK866 loaded bismuth-humic acids heterojunction (Bi-HA/FK866). With the reduction function of HA, Bi (Ⅲ) can be reduced to elemental Bi, which can be excited by NIR laser to form electron-hole pair due to the narrow bandgap. Moreover, the coated HA and Bi could form a heterojunction structure, which could decrease the electron-hole recombination, and further boost the photocatalytic activity, leading to highly efficient ROS generation and GSH depletion. The resulted ROS could induce DNA damage of the tumor cells, thus enhancing the sensitivity to the inhibitor of NAMPT (FK866) to downregulate NAD/ERK/NF-κB signal pathways, and eventually simultaneously prevent cancer progression. Moreover, the decreased NAD could downregulate NADPH and further suppress the innate antioxidant defense system by inhibiting reduction of GSSG. The boosted photocatalytic activity induced NAMPT-regulating therapy offers a promising way to address the important issue of penetration depth limitation induced cancer relapse and migration, providing more possibilities toward successful clinical application.

Oxygen-supplementing mesoporous polydopamine nanosponges with WS2 QDs-embedded for CT/MSOT/MR imaging and thermoradiotherapy of hypoxic cancer.

Multifunctional nanoplatforms with flexible architectures and tumor microenvironment response are highly anticipated within the field of thermoradiotherapy. Herein, the multifunctional nanoplatforms for thermoradiotherapy have been successfully constructed by the embedding of tungsten disulfide quantum dots (WS2 QDs) into mesoporous polydopamine nanosponges (MPDA NSs), followed by integration with manganese dioxide (MnO2). MPDA-WS2@MnO2, the resultant nanoplatforms, exhibit radiosensitization enhanced behavior and a capacity for responsive oxygen self-supplementation. The ingenious mesoporous structure of MPDA NSs serves as reservoir for the assembly of WS2 QDs to form MPDA-WS2 nanoparticles (NPs), in which WS2 QDs provide the radiation enhancement effect, whereas the MPDA NSs framework endows the MPDA-WS2@MnO2 with an excellent photothermal capability. Additionally, the integration of the MnO2 component works to decompose the tumor-overexpressed H2O2 and alleviate tumor hypoxia subsequently, which has been demonstrated to enhance radiotherapy performance considerably. Meanwhile, the prepared MPDA-WS2@MnO2 nanoplatforms have been evaluated as trimodality contrast agents for computed tomography (CT), multispectral optoacoustic tomography (MSOT), and tumor microenvironment-responsive T1-weighted magnetic resonance (MR) imaging that have the potential for real-time guidance and monitoring during cancer therapy. More importantly, when subjected to near infrared (NIR) laser irradiation and X-ray exposure, the tumor is found to be inhibited significantly through the process of combined thermoradiotherapy. The design concepts of embedding WS2 QDs into MPDA NSs and oxygen self-supplementing hold great potential for multimodal imaging-guided thermoradiotherapy of hypoxic cancer.

Rodlike MSN@Au Nanohybrid-Modified Supermolecular Photosensitizer for NIRF/MSOT/CT/MR Quadmodal Imaging-Guided Photothermal/Photodynamic Cancer Therapy.

Recently, rodlike nanomaterials with specific aspect ratio for efficient cellular uptake have received enormous attention. For functional nanomaterials, such as photothermal agents, large surface areas for their rod-shaped exterior that increase the amount of light absorbed would lead to a higher absorption coefficient as well as drug-loading property. In this project, we coated rodlike mesoporous silica with gold nanoshells (MSNR@Au hybrid), modifying them with ultrasmall gadolinium (Gd)-chelated supramolecular photosensitizers, TPPS4 (MSNR@Au-TPPS4(Gd)), which could be applied to near-infrared fluorescence/multispectral optoacoustic tomography/computed tomography/magnetic resonance imaging and imaging-guided remotely controlled photothermal (PTT)/photodynamic (PDT) combined antitumor therapy. Gold nanoshells, as a perfect PTT agent, were used to assemble the rodlike mesoporous silica nanoparticles with larger superficial area and higher drug loading, thus obtaining the MSNR@Au hybrid. HS-ß-CD, which was used as the host, was adsorbed on the gold nanoshell (MSNR@Au-ß-CD) to link TPPS4(Gd) through the host-guest reaction, thus forming CD-TPPS4 supramolecular photosensitizers (supraPSs). Compared with conventional PSs, supraPSs have host screens, which could reduce the self-aggregation of TPPS4, and consequently generate 1O2 with high efficiency. The in vivo quadmodal imaging of MSNR@Au-TPPS4(Gd) nanoparticles revealed an intensive tumor uptake effect after injection. The in vivo antitumor efficacy further testified that the synergistic therapy, which was more efficient than any other monotherapy, exhibited an excellent tumor inhibition therapeutic effect. As a result, this encourages to further explore multifunctional theranostic nanoparticles based on gold shells for combined cancer therapy.

Biomodal Tumor-Targeted and Redox-Responsive Bi2 Se3 Hollow Nanocubes for MSOT/CT Imaging Guided Synergistic Low-Temperature Photothermal Radiotherapy.

Hyperthemia (>50 °C) induced heating damage of nearby normal organs and inflammatory diseases are the main challenges for photothermal therapy (PTT) of cancers. To overcome this limitation, a redox-responsive biomodal tumor-targeted nanoplatform is synthesized, which can achieve multispectral optoacoustic tomography/X-ray computed tomography imaging-guided low-temperature photothermal-radio combined therapy (PTT RT). In this study, Bi2 Se3 hollow nanocubes (HNCs) are first fabricated based on a mild cation exchange way and Kirkendall effect and then modified with hyaluronic acid (HA) through redox-cleavable linkage (-s-s-), thus enabling the HNC to target cancer cells overexpressing CD-44 and control the cargo release profile. Finally, gambogic acid (GA), a type of heat-shock protein (HSP) inhibitor, which is vital to cells resisting heating-caused damage is loaded, into Bi2 Se3 HNC. Such HNC-s-s-HA/GA under a mild NIR laser irradiation can induce efficient cancer cell apoptosis, achieving PTT under relatively low temperature (≈43 °C) with remarkable cancer cell damage efficiency. Furthermore, enhanced radiotherapy (RT) can also be experienced without depth limitation based on RT sensitizer Bi2 Se3 HNC. This research designs a facile way to synthesize Bi2 Se3 HNC-s-s-HA/GA possessing theranostic functionality and cancer cells-specific GSH, but also shows a low-temperature PTT RT method to cure tumors in a minimally invasive and highly efficient way.