Bismuth Sulfide Nanoparticles Research Articles

Implantable, 3D-Printed Alginate Scaffolds with Bismuth Sulfide Nanoparticles for the Treatment of Local Breast Cancer via Enhanced Radiotherapy.

Surgical removal of tumor tissue remains the primary clinical approach for addressing breast cancer; however, complete tumor excision is challenging, and the remaining tumor cells can lead to tumor recurrence and metastasis over time, which substantially deteriorates the life quality of the patients. With the aim to improve local cancer radiotherapy, this work reports the fabrication of alginate (Alg) scaffolds containing bovine serum albumin (BSA)-coated bismuth sulfide (Bi2S3@BSA) nanoradiosensitizers using three-dimensional (3D) printing. Under single-dose X-ray irradiation in vitro, Alg-Bi2S3@BSA scaffolds significantly increase the formation of reactive oxygen species, enhance the inhibition of breast cancer cells, and suppress their colony formation capacity. In addition, scaffolds implanted under tumor tissue in murine model show high therapeutic efficacy by reducing the tumor volume growth rate under single-dose X-ray irradiation, while histological observation of main organs reveals no cytotoxicity or side effects. 3D-printed Alg-Bi2S3@BSA scaffolds produced with biocompatible and biodegradable materials may potentially lower the recurrence and metastasis rates in breast cancer patients by inhibiting residual tumor cells following postsurgery as well as exhibit anticancer properties in other solid tumors.

Ecologically sustainable removal of pharmaceuticals: A mechanistic study of bismuth sulfide-graphene oxide/silver nanocomposite

Bismuth sulfide nanoparticles (BiS NPs) were synthesized via the hydrothermal method, and reduced graphene oxide(rGO) and silver nanoparticles (Ag), which acted as substrates, have prepared using the chemical reduction method. The synthesized nanoparticles have been characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), ultraviolet–visible spectroscopy, and photoluminescence spectroscopy. Commercially available paracetamol-500 mg (PAM) and aspirin-300 mg (ASP) were selected for photodegradation under visible light using the as-prepared composites in an aqueous solution. Photoluminescence spectroscopy was used to detect PAM and ASP using the photo-excited electron transfer (PET) process, and the limit of detection (LOD) has obtained for PAM(8.70 ppm) and ASP(4.43 ppm) with a sensitivity of 0.9954 and 0.8002, respectively. Fourier transform infrared spectroscopy (FTIR) was used to analyze the before and after degradation products and to confirm the disintegrated products such as –COOH and –CH– both before and after disintegration.. The experimental data were found to fit well with the Freundlich isotherm, suggesting that the as-prepared nanocomposites exhibited a heterogeneous nature for PAM (5119 mg/L), and the pseudo-first-order kinetic model suggests ASP (1030 mg/L) with R2 values of 0.9119 and 0.7075. The risk assessment analysis of PAM was 9.823 μg/L(RQ > 1) and that of ASP was 0.2106 μg/L(RQ < 1), indicating that PAM has a higher potential risk than ASP. The demographic data of the participants indicated that PAM was the most stockpiled medicine at home; this work also encompasses the action of a single PAM and ASP tablet toward the environment, if it is accidently disposed of improperly could create massive water/soil pollution; hence, the care/duty of each person should follow the proper disposal of medical waste because we cannot replace this environment.

Sandwich composites of bismuth sulfide nanoparticles decorated with cobalt ferrite oxide for waste water treatment

To detect cadmium (Cd2+) ions, electrochemical and calorimetric studies have been performed due to their high sensitivity and selectivity. Heterogeneous photocatalysts have been used to degrade and decolorize azo dyes because they are adaptable, cause less secondary pollution, and are cost-effective. In this study, synthesized Bi2S3 nanoparticles adorned on CoFe2O4 (BiSNPs@CFO) substrates by using chemical methods. The primary source of Cd2+ ions in digested detergent samples was detected and coded as samples A, B, and C. Laundry wastewater was denoted as sample D. Both photoluminescence spectroscopy (PL) and cyclic voltammetry techniques (CV) were employed to detect the presence of cadmium ion in the selected samples. Pollution assessment risk index values indicated that samples B and C contributed to Cd2+ ions pollution more compared with sample A. The Igeo (geo-accumulation) values were 4.08 (sample B), 3 (sample C), and 13.5 (sample D), which indicated a high pollution level. Then, the methylene blue (MB) dye was periodically degraded at a fixed concentration and pH, and the efficiency reached 83%, with the apparent rate constant of 0.0106/min with a high R2 value of approximately 0.9015. In this study, the two pathogens were isolated from laundry wastewater, namely, Aspergillus sp. and Trichoderma sp, and their growth and biomass production were examined. The antifungal activity of BiSNPs@CFO composites was studied using the standard fluconazole. The nanocomposites can be used as a probe to detect the presence of Cd2+ ions and degrade azo dyes and Aspergillus sp. and Trichoderma sp. predominantly grown in laundry wastewater.

Mercury removal from aqueous media by aminated polyacrylonitrile beads impregnated with nano-urchin bismuth sulfide particles: Experimental and theoretical analysis under batch and continuous mode

The present study encompasses a thorough analysis of aqueous Hg (II) adsorption using aminated polyacrylonitrile beads incorporated with high-capacity surfactant assisted bismuth sulfide nanoparticles. The porous beads provided effective contact between aqueous Hg and the inorganic nano-adsorbent (PBS2) that was encapsulated in the matrix. The macro-sized beads served as suitable packing material for designing a fixed bed adsorption column for continuous mode analysis without significant pressure build up and offered an easy solid–liquid separation after treatment. A marginal negative zeta potential of the adsorbent beads improved the interaction with Hg2+ facilitating the sorption. The incorporation of amine groups into the polymeric bead surface via amination increased the adsorption capacity further from 83.30 mg/g to 130.00 mg/g (∼56.00%) at 303 K. The associated parameters of batch kinetics (effective pore diffusivity and mass transfer coefficient) were determined using a first principle-based model available in literature. Mercury was chemisorbed via synergistic lone pair interactions of S and N atoms with Hg, leading to formation of coordination bonds (Hg-S and Hg-N). An established mass transfer model was utilized to generate simulated breakthrough curves for the continuous analysis using synthetic feed. Additionally, the adsorption column showed comparable performance using both synthetic and real water samples (synthetically spiked) maintaining high selectivity. The optimized values of axial dispersion coefficient (Ez) and fixed bed mass transfer coefficient (kfb) were estimated and subsequently used for the scale up studies to predict column life. The adsorbent beads were regenerated using 0.05 M EDTA aqueous solution and showed good reusability (>95.00%) after 5 cycles of operation. Overall, this work highlights a reusable Hg adsorbent possessing good selectivity and capacity and simultaneously demonstrating real-field applicability.

Radiosensitivity Enhancement using Triptorelin Conjugated Bismuth Sulfide Nanoparticles (Bi2S3@BSA) in Radiotherapy for Breast Cancer Cells

The aim of this study was to assess the radiosensitivity of bismuth sulfide nanoparticles conjugated with a synthetic agonist analog of gonadotropin-releasing hormones in targeted radiotherapy for breast cancer. After synthesis and characterization of nanoparticles, cytotoxicity of nanoparticles was measured by MTT assay, and the survival fraction was determined by colony formation assay. Finally, flow cytometry was performed to identify the mechanism of radiosensitization. Characterization results determined the spherical shape of Bi2S3@BSA with an average size of 8.649 ± 1.6 nm, and Fourier transform infrared confirmed the successful binding of triptorelin to the surface of the nanoparticles. MTT test results show that the Bi2S3@BSA–triptorelin did not cause any toxicity ( P &lt; 0.05 ) even up to 75 μg/ml. At all doses of ionizing radiation, colony formation assays showed that the nontoxic concentration of Bi2S3@BSA–triptorelin significantly increased cell death in MCF-7 cells compared to Bi2S3@BSA ( P &lt; 0.05 ). The apoptosis test also confirmed colony formation assay results at all doses and introduced apoptosis as a mechanism of radiosensitivity produced by nanoparticles. Certainly, targeted bismuth sulfide nanoparticles can be a good candidate for increasing radiosensitivity against tumor cells.

Adsorptive remediation of aqueous inorganic mercury with surfactant enhanced bismuth sulfide nanoparticles

Heavy metal contamination in water is a growing threat, endangering the environmental stability. Mercury (Hg) is one of the most lethal heavy metals damaging the immune and nervous system irreversibly. A novel synthetic route to prepare bismuth sulfide (Bi2S3) nanoparticles in presence of the surfactant Pluronic (P123) was illustrated in this work. The sorption of Hg (II) by the nanoparticles was investigated. The surfactant assisted nanoparticles showed enhanced surface area and potential compared to the unmodified ones. The effects of adsorbent dose, pH, initial concentration, and temperature were investigated. The maximum Hg (II) adsorption capacity for the surfactant enhanced Bi2S3 was 832 mg/g at 303 K and pH 5. The distribution coefficient (Kd) of the order ∼106 ml/g indicated high selectivity of the synthesized adsorbent toward mercury ions. Chemisorption was identified to be the dominant mechanism of adsorption. The adsorbent also showed excellent reusability (>95%) after 5 cycles. The transport parameters involved in the adsorption, the effective pore diffusivity (Dp: 7.36 × 10−12 m2/s) and the mass transfer coefficient (kf: 1.52 × 10−6 m/s) were estimated from a first principle-based model.

A cross-linked hydrogel of bismuth sulfide nanoparticles with excellent photothermal antibacterial and mechanical properties to combat bacterial infection and prompt wound healing

Wound healing has always faced major challenges. Severe bacterial infections can delay healing and even be life-threatening. According to relevant statistics, 70% of amputations are caused by wound infections. It is estimated that by 2050, drug-resistant bacteria will threaten the lives of 10 million people every year and cause a total loss of about 100 trillion U.S. dollars to the global economy. Therefore, there is an urgent need to develop new and efficient wound dressings that can effectively treat wound infections and promote wound healing while avoiding bacterial resistance. In this study, bismuth sulfide nanoparticles (Bi2S3 NPs) with good photothermal effect were combined with sodium alginate/acrylamide hydrogels (PAAm/NaAlg hydrogels) to prepare nanocomposite adhesive hydrogels (Bi2S3 NPs hydrogels) with strong antibacterial activity and good biocompatibility. Bi2S3 NPs can effectively convert light energy into heat energy and produce a certain amount of reactive oxygen species (ROS) to denature bacterial proteins and destroy cell membranes. In vivo experiments showed that hydrogels have a certain adhesion ability and can effectively promote wound healing without using any growth factors. As far as we know, this is the first time that Bi2S3 NPs were combined with hydrogels to be applied in the antibacterial field, which is expected to provide exciting research directions for Bi2S3 and other nanomaterials, and promote researchers to design more suitable dressings for clinical transformation and medical care.

Starch-Assisted Synthesis of Bi2S3 Nanoparticles for Enhanced Dielectric and Antibacterial Applications.

Starch [(C6H10O5) n ]-stabilized bismuth sulfide (Bi2S3) nanoparticles (NPs) were synthesized in a single-pot reaction using bismuth nitrate pentahydrate (Bi(NO3)3·5H2O) and sodium sulfide (Na2S) as precursors. Bi2S3 NPs were stable over time and a wide band gap of 2.86 eV was observed. The capping of starch on the Bi2S3 NPs prevents them from agglomeration and provides regular uniform shapes. The synthesized Bi2S3 NPs were quasispherical, and the measured average particle size was ∼11 nm. The NPs are crystalline with an orthorhombic structure as determined by powder X-ray diffraction and transmission electron microscopy. The existence and interaction of starch on the NP's surface were analyzed using circular dichroism. Impedance spectroscopy was used to measure the electronic behavior of Bi2S3 NPs at various temperatures and frequencies. The dielectric measurements on the NPs show high dielectric polarizations. Furthermore, it was observed that the synthesized Bi2S3 NPs inhibited bacterial strains (Bacillus subtilis, Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus) and demonstrated substantial antibacterial activity.

Pseudocapacitive boosts nanoparticles composed of sea urchin structure Bi2S3-xSex@rGO with high rate and capacity for sodium ion battery anode

The abundant reserve and low cost of sodium over lithium has prompted an enormous development for sodium-ion batteries(SIBs). SIBs are expected to replace lithium ion batteries in the future and be widely applied. Reliable anodes are one of the key issues in the commercial application of SIBs. Herein, an elaborate sea urchin-shaped Se-doped Bi2S3 (Bi2S3-xSex@rGO) electrode is designed by hydrothermal method for SIBs. The Bi2S3-xSex@rGO electrode exhibits an excellent rate capability (694 mAh g −1 at 2 A g−1)and high reversible capacity (701 mAh g −1 after 100 cycles at 0.1 A g −1), which are superior to those of most Bi2S3 for SIBs anode reported previously. Pseudocapacitive contribution is demonstrated as the main reason of prominent electrochemical performance of the Bi2S3-xSex@rGO electrode. The sea urchin-like structure is composed of bismuth sulfide nanoparticles, which promotes the pseudocapacitance behavior of the electrode. The pseudocapacitance promoted by rapid transport of sodium ions could extend to more advanced SIBs anodes.

Design and fabrication of chitosan cross-linked bismuth sulfide nanoparticles for sequestration of mercury in river water samples

The existence of heavy metals in ecological systems poses great threats to living organisms due to their toxicant and bio-accumulating properties. Mercury is a known toxicant with notable malignant impacts. It has long been known to cause toxic threats to the health of living organisms since the break out of Minamata disease. The turbulent expulsion of mercury-based pollutants from the industrial sector, requires a proper solution. Many attempts have been made to design a greener and more efficient route for a satisfactory removal of mercury. In the current study, bismuth sulfide nanoparticles (BiSNPs) have been synthesized via the co-precipitation method. The BiSNPs were supported with crosslinked chitosan to enhance their sorption capacity and avoid leaching. The average size of the BiSNPs was 42 nm based on SEM micrographs. The SEM analysis of the bismuth sulfide chitosan-crosslinked beads (BiS-CB) showed that the beads possessed a spherical and smooth morphology with a size of 1.02 mm. The FTIR analysis showed that the beads possessed the characteristics bands of imine groups of chitosan, bismuth, sulfur, and glycosidic linkages present in the molecules. The XRD analysis confirmed the phase crystallinity of the BiS-CB with an average crystallite size of 11 nm. The BiS-CB was employed for the sorption of mercury from water samples. The maximum sorption capacity of 65.51 mg/g was achieved at optimized conditions of pH 5, concentration 80 ppm, in 45 min at 30 °C. The mechanism studied for mercury removal showed that sorption followed the complexation mechanism according to the SHAB concept. In conclusion, the results showed that the BiS-CB sorbent exhibited an excellent sorption capacity to remove mercury.

Oxygen vacancies and Bi2S3 nanoparticles co-sensitized TiO2 nanotube arrays for enhanced photoelectrochemical sensing of chlorpyrifos

Due to the environmental pollution and food safety problems that caused by the abuse of chlorpyrifos (CPF), a strategy of which is detected with high efficiency is urgently demanded. Herein, a photoelectrochemical sensor which using TiO2 nanotube arrays with oxygen vacancies (Vo-TNTAs) as electrode was constructed. Oxygen vacancies are introduced into TNTAs in order to generate a new defect level that narrows its band gap. The bismuth sulfide nanoparticles are loaded on Vo-TNTAs to accelerate the separation of electron-hole pairs. Thus, the Bi2S3/Vo-TNTAs hetero-structure is designed and constructed. With the existence of CPF, a complex which composed by Bi ions and CPF will be formed in situ to block the electrons transfer from electron donor (ascorbic acid) to Bi2S3, causing the weakened photocurrent. Consequently, the Bi2S3/Vo-TNTAs electrode possess higher photocurrent response than that of pure Vo-TNTAs and TNTAs. The Bi2S3/Vo-TNTAs-based PEC sensor displays a linear range of 0.07–3.0 μmol/L with a detection limit of 6.0 nmol/L (S/N = 3) and can be utilized for CPF detection in lettuce and cucumber samples with recoveries of 95.7 to 110 %.

DNA-Templated ultrasmall bismuth sulfide nanoparticles for photoacoustic imaging of myocardial infarction

Photoacoustic imaging (PAI) has shown great clinical potential in diagnosing various diseases due to its noninvasive, cost-effective, and real-time imaging properties but is limited by the lack of contrast agents with high sensitivity for deep tissue imaging. Here, DNA-templated ultrasmall bismuth sulfide (Bi2S3) nanoparticles (NPs) were reported as a photoacoustic (PA) probe for imaging myocardial infarction. We present a simple synthesis strategy of ultrasmall NPs via self-assembly of single-stranded DNA (ssDNA)/metal ion complexes. The in vivo imaging results showed a dramatically enhanced PA signal in the region of myocardial infarction after intravenous injection of DNA-Bi2S3 NPs in the myocardial ischaemia/reperfusion (I/R) mouse model. Further near infrared fluorescence imaging indicated that Bi2S3 NPs mainly accumulated in the infarcted area, leading to enhancement of PA signals. Moreover, such hybrid NPs possess a well-defined nanostructure, superior photobleaching resistance, excellent water dispersibility and negligible acute toxicity. These results not only demonstrate that ultrasmall DNA-Bi2S3 NPs are a potent PA probe for imaging the infarcted region but also provide a new avenue for preparing ultrasmall-sized PA probes by using ssDNA as a template.

Solvothermal synthesis of Bi2S3 nanoparticles for active photocatalytic and energy storage device applications

High edge energy storage with large life-span stable materials have become the most significant and major requirement in near future. Bismuth sulfide (Bi2S3) nanoparticles (NPs) was effectively synthesized by utilizing bismuth diethyldithiocarbamate (Bi[DTC]3) complex as single-source antecedent. The synthesized Bi2S3 NPs were affirmed by structural, morphological and thermal analysis with various analytical studies. The electrochemical performance of Bi2S3 NPs reveals that, exhibit redox behavior from cyclic voltammetry analysis, the charge–discharge analysis was examined by the galvanostatic chronopotentiometry. Bi2S3 NPs exhibit excellent supercapacitor behavior with value of the specific capacitance 470 Fg−1 at current density 0.5 Ag−1 and the retentivity of 79% after 1000 cycles. The Bi2S3 NPs were further utilized as photocatalytic discoloration of Congo Red (CR) dye in aqueous medium under UV light irradiation. Which shows, excellent catalytic behaviour, up to 98% of CR dye degrade within 150 min and it is exhibit good catalytic stability and reusability.

Autophagic blockage by bismuth sulfide nanoparticles inhibits migration and invasion of HepG2 cells

The biological effects of nanoparticles are of great importance for the in-depth understanding of safety issues in biomedical applications. Induction of autophagy is a cellular response after nanoparticle exposure. Bismuth sulfide nanoparticles (Bi2S3 NPs) are often used as a CT contrast agent because of their excellent photoelectric conversion ability. Yet there has been no previous detailed study other than a cell toxicity assessment. In this study, three types of Bi2S3 NPs with different shapes (Bi2S3 nano rods (BSNR), hollow microsphere Bi2S3 NPs (BSHS) and urchin-like hollow microsphere Bi2S3 NPs (ULBSHS)) were used to evaluatecytotoxicity, autophagy induction, cell migration and invasion in human hepatocellular carcinoma cells (HepG2). Results showed that all three Bi2S3 NPs lead to blockage in autophagic flux, causing p62 protein accumulation. The cell death caused by these Bi2S3 NPs is proved to be autophagy related, rather than related to apoptosis. Moreover, Bi2S3 NPs can reduce the migration and invasion in HepG2 cells in an autophagy-dependent manner. ULBSHS is the most cytotoxic among three Bi2S3 NPs and has the best tumor metastasis suppression. These results demonstrated that, even with relatively low toxicity of Bi2S3 NPs, autophagy blockage may still substantially influence cell fate and thus significantly impact their biomedical applications, and that surface topography is a key factor regulating their biological response.

Tetramodal Imaging and Synergistic Cancer Radio-Chemotherapy Enabled by Multiple Component-Encapsulated Zeolitic Imidazolate Frameworks.

The abundant species of functional nanomaterials have attracted tremendous interests as components to construct multifunctional composites for cancer theranostics. However, their distinct chemical properties substantially require a specific strategy to integrate them in harmony. Here, we report the preparation of a distinctive multifunctional composite by encapsulating small-sized semiconducting copper bismuth sulfide (CBS) nanoparticles and rare-earth down-conversion (DC) nanoparticles in larger-sized zeolitic imidazolate framework-8 (ZIF8) nanoparticles, followed by loading an anticancer drug, doxorubicin (DOX). Such composites can be used for tetramodal imaging, including traditional computed tomography and magnetic resonance imaging and, recently, for photoacoustic imaging and fluorescence imaging. With a pH-responsive release of the encapsulated components, synergistic radio-chemotherapy with a high (87.6%) tumor inhibition efficiency is achieved at moderate doses of the CBS&DC-ZIF8@DOX composite with X-ray irradiation. This promising strategy highlights the extending capacity of zeolitic imidazolate frameworks to encapsulate multiple distinct components for enhanced cancer imaging and therapy.

Mo-doped porous BiVO4/Bi2S3 nanoarray to enhance photoelectrochemical efficiency for quantitative detection of 17β-estradiol

A new porous nanoarray is constructed as sensing platform of photoelectrochemical (PEC) biosensor for detection of 17β-estradiol (E2) by using aptamer. The molybdenum (Mo) ions doped into porous bismuth vanadate (Mo-p BiVO4) nanoarray by electrodeposition of BiOI nanoarray. Then, the bismuth sulfide (Bi2S3) nanoparticles are grown in-situ on the surface of Mo-p BiVO4 by the self-sacrificial synthesis method to form novel Mo-p BiVO4/Bi2S3 heterojunction. Herein, the Mo-p BiVO4/Bi2S3 heterojunction presents a high PEC signal because of Mo-p BiVO4 could increase electron-hole separation yield by supplying additional free electrons, furthermore the heterojunction of Mo-p BiVO4/Bi2S3 could promote ultrafast transfer of charge and inhibit the recombination of e−/h+ pairs by presenting cascade band-edge levels under irradiation of the visible light. Moreover, the nanoarray structure has large specific surface area, which could accelerate electron transfer and provide large number of binding sites to immobilize aptamer. This PEC aptamer sensor exhibits high sensitivity with a detection limit 3.2 × 10-4 pM and a good photocurrent response toward target E2 in the range of 1 × 10-3 - 5 × 102 pM. Good specificity and stability are acquired for analysis of E2 in human urine. Importantly, this designed sensor platform of Mo-p BiVO4/Bi2S3 heterojunction provides a new promising application for other environmental estrogen analysis.

Preparation of bismuth sulfide nanoparticles as targeted biocompatible nano‐radiosensitizer and carrier of methotrexate

In this study, Bi2S3@BSA–Bio–MTX nanoparticles (NPs) were synthesized for the first time by bovine serum albumin (BSA)‐mediated biomineralization (Bi2S3@BSA NPs) followed by covalent bonding of biotin (Bio) and methotrexate (MTX) on the surface of the Bi2S3@BSA NPs via carbodiimide chemistry. The synthesized NPs were globular and exhibited uniform morphology with a hydrodynamic diameter of 107.6 ± 6.81 nm (mean ± standard deviation) and zeta potential of −20.9 ± 2.18 mV. Drug release from Bi2S3@BSA–Bio–MTX NPs indicated an enzyme‐dependent release pattern. The in vitro biocompatibility of NPs was confirmed by investigating their cytotoxicity against the HEK‐293 cell line and hemolysis assay test, whereas the in vivo biocompatibility of the NPs was evaluated and confirmed by the lethal dose 50 (LD50) test. To evaluate the in vitro anticancer activity of the functionalized NPs and MTX, their cytotoxic effects was assessed against 4T1 cancer cells by 5‐dimethylthiazol‐z‐yl)‐2,5‐diphenyltetrazolium bromide (MTT) assay with and without X‐ray radiation. Results showed that Bi2S3@BSA–Bio–MTX NPs have excellent anticancer activity, especially following X‐ray radiation.

Vacancy doping and charge transport in Bi2S3 nanoparticle films for photovoltaic applications

Native point defect doping via thermal treatment is an easy and promising method to tune the electrical transport properties of semiconductors made for renewable-energy conversion. In this study, we investigate the vacancy doping of the lowly toxic semiconductor $\mathrm{B}{\mathrm{i}}_{2}{\mathrm{S}}_{3}$ using electrical conductivity as well as thermoelectric power measurements. We enhance the electrical conductivity of bismuth sulfide nanoparticle layers by more than four orders of magnitude by a stepwise thermal treatment in a moderate temperature range (300--480 K). Via thermoelectric power measurements we attribute this enhancement to an increase in charge-carrier mobility by two orders of magnitude and to an increase in charge-carrier density by more than two orders of magnitude. We find that the energetic position of the electron-doping sulfur vacancies of bismuth sulfide nanoparticles is significantly shallower than previously reported for bulk material. Subsequently, we implement $\mathrm{B}{\mathrm{i}}_{2}{\mathrm{S}}_{3}$ nanoparticles doped with sulfur vacancies by thermal annealing in photovoltaic devices using P3HT as an electron donor molecule. We find that annealing up to 383 K yields the best compromise between improving charge-carrier transport and increasing defect densities.

Tumor Targeted Albumin Coated Bismuth Sulfide Nanoparticles (Bi2S3) as Radiosensitizers and Carriers of Curcumin for Enhanced Chemoradiation Therapy.

Combination therapy such as radiotherapy combined with chemotherapy has attracted excessive interest in the new cancer research area. Therefore, developing nanobiomaterials for combination of radiotherapy and chemotherapy is required for more powerful and successful cures. Because of the amazing X-ray sensitization proficiency of Bi based nanoparticles, in this work, we synthesized and used Bi2S3 as an enhancer of X-ray radiation therapy, and furthermore, Bi2S3 served as carrier of curcumin (CUR), a chemotherapy drug, for the goal of combination therapy. Additionally, we selected and conjugated folic acid (FA) as a targeting molecule for the direction of the designed system to the tumor site. After characterization of drug loaded FA conjugated Bi2S3@BSA nanoparticles (Bi2S3@BSA-FA-CUR) and in vitro and in vivo safety assessment, we applied it for enhanced chemotherapy and X-ray radiation therapy in cancer cells and a tumor bearing mice model. Moreover, the CT contrast ability of synthesized nanoparticles was examined. Here, we (1) for the first time developed the novel and targeted CUR loaded Bi2S3@BSA (Bi2S3@BSA-FA-CUR) to promote chemoradiation therapy in 4T1 cells and breast tumor in mice; (2) found the synthesized nanoparticles to have good stability; (3) injected a single dose of the designed radiosensitizer for cancer therapy; and (4) used a conventional X-ray dose, 2Gy, for X-ray radiation therapy. The result of in vivo X-ray radiotherapy shows that the mice tumors vanished near 3 weeks after radiation. Interestingly, these results show that Bi2S3@BSA-FA-CUR with the aid of X-ray can clearly promote the efficacy of chemoradiation therapy.

Effective Radiotherapy in Tumor Assisted by Ganoderma lucidum Polysaccharide-Conjugated Bismuth Sulfide Nanoparticles through Radiosensitization and Dendritic Cell Activation.

Radiotherapy is a traditional method for cancer therapy but may become ineffective likely due to the radiation-induced immunosuppression. Instead of simply increasing the radiation dose, reactivation of immunosuppression in the tumor microenvironment is an alternative strategy for successful cancer treatment. In this work, we synthesized bismuth sulfide nanoparticles (BiNP) and conjugated with immunoactive Ganoderma lucidum polysaccharide (GLP). GLP-BiNP were able to increase the sensitivity of radiotherapy, attributing to the efficient X-ray absorption of bismuth element. BiNP alone can mildly activate dendritic cells (DC) in vitro, while GLP-BiNP further enhanced the level of DC maturation, shown as the increase in phenotypic maturation markers, cytokine release, acid phosphatase activity, and T cell proliferation in DC/T cell co-culture. Compared to BiNP, GLP-BiNP altered the tissue distribution with faster accumulation in the tumor. Meanwhile, mature DC greatly increased in both tumor and spleen by GLP-BiNP within 24 h. GLP-BiNP combination with radiation achieved remarkable inhibition of tumor growth through apoptosis. Alternatively, lung metastasis was largely prohibited by GLP-BiNP, shown as a reduced amount of tumor nodules and cancer cell invasion by pathological findings. Mechanistically, GLP-BiNP altered the tumor immunosuppression microenvironment by preferably increasing the number of intratumor CD8+ T cell proliferation, as well as the improved immunobalance shown as the increased serum interferon-γ/interleukin-4 ratio. Specifically, GLP conjugation seemed to protect the kidney from injury occasionally introduced by bare BiNP. As a result, GLP-BiNP play a dual role in tumor treatment through radiosensitization and immunoactivities.