Doxorubicin loaded silica nanorattles actively seek tumors with improved anti-tumor effects

Silica nanorattles (SNs) have proven to be promising vehicles for drug delivery. In order to further enhance efficacy and minimize adverse effects, active targeted delivery to tumors is necessary. In this work, SNs modified with a tumor specific targeting ligand, folic acid (FA), was used as carrier of doxorubicin (DOX) (DOX-FA-SNs). Drug loading, cytotoxicity and cellular uptake of DOX-FA-SNs in vitro in human cervical carcinoma cells (HeLa cells) were evaluated. DOX-FA-SNs showed a higher cytotoxicity in human cervical carcinoma cells (HeLa cells) than DOX loaded carboxyl (-COOH) and poly(ethylene glycol) (PEG) modified SNs (DOX-COOH-SNs and DOX-PEG-SNs, respectively). However, DOX-FA-SNs showed lower cytotoxicity in folate receptor negative normal mouse fibroblast cells (L929 cells) compared with free DOX. In vivo tumor-targeted fluorescence imaging indicated specific tumor targeting and uptake of FA-SNs in nude mice bearing subcutaneous HeLa cell-derived xenograft tumors. In vivo anti-tumor experiments demonstrated that DOX-FA-SNs (10 mg kg(-1) of DOX) significantly regressed the tumor growth and reduced toxicity compared with free DOX. These results have great significance in developing and optimizing SNs as effective intracellular delivery and specific tumor targeting vehicles.     

Highly biocompatible TiO₂:Gd³⁺ nano-contrast agent with enhanced longitudinal relaxivity for targeted cancer imaging

We report the development of a novel magnetic nano-contrast agent (nano-CA) based on Gd(3+) doped amorphous TiO(2) of size ～25 nm, exhibiting enhanced longitudinal relaxivity (r(1)) and magnetic resonance (MR) contrasting together with excellent biocompatibility. Quantitative T1 mapping of phantom samples using a 1.5 T clinical MR imaging system revealed that the amorphous phase of doped titania has the highest r(1) relaxivity which is ～2.5 fold higher than the commercially used CA Magnevist?. The crystalline (anatase) samples formed by air annealing at 250 °C and 500 °C showed significant reduction in r(1) values and MR contrast, which is attributed to the loss of proton-exchange contribution from the adsorbed water and atomic re-arrangement of Gd(3+) ions in the crystalline host lattice. Nanotoxicity studies including cell viability, plasma membrane integrity, reactive oxygen stress and expression of pro-inflammatory cytokines, performed on human primary endothelial cells (HUVEC), human blood derived peripheral blood mononuclear cells (PBMC) and nasopharyngeal epidermoid carcinoma (KB) cell line showed excellent biocompatibility up to relatively higher doses of 200 μg ml(-1). The potential of this nano-CA to cause hemolysis, platelet aggregation and plasma coagulation were studied using human peripheral blood samples and found no adverse effects, illustrating the possibility of the safe intravenous administration of these agents for human applications. Furthermore, the ability of these agents to specifically detect cancer cells by targeting molecular receptors on the cell membrane was demonstrated on folate receptor (FR) positive oral carcinoma (KB) cells, where the folic acid conjugated nano-CA showed receptor specific accumulation on cell membrane while leaving the normal fibroblast cells (L929) unstained. This study reveals that the Gd(3+) doped amorphous TiO(2) nanoparticles having enhanced magnetic resonance contrast and high biocompatibility is a promising candidate for molecular receptor targeted MR imaging.     

SI-ATRP Decoration of Magnetic Nanoparticles with PHEMA and Post-Polymerization Modification with Folic Acid for Tumor Cells’ Specific Targeting

Targeted nanocarriers could reach new levels of drug delivery, bringing new tools for personalized medicine. It is known that cancer cells overexpress folate receptors on the cell surface compared to healthy cells, which could be used to create new nanocarriers with specific targeting moiety. In addition, magnetic nanoparticles can be guided under the influence of an external magnetic field in different areas of the body, allowing their precise localization. The main purpose of this paper was to decorate the surface of magnetic nanoparticles with poly(2-hydroxyethyl methacrylate) (PHEMA) by surface-initiated atomic transfer radical polymerization (SI-ATRP) followed by covalent bonding of folic acid to side groups of the polymer to create a high specificity magnetic nanocarrier with increased internalization capacity in tumor cells. The biocompatibility of the nanocarriers was demonstrated by testing them on the NHDF cell line and folate-dependent internalization capacity was tested on three tumor cell lines: MCF-7, HeLa and HepG2. It has also been shown that a higher concentration of folic acid covalently bound to the polymer leads to a higher internalization in tumor cells compared to healthy cells. Last but not least, magnetic resonance imaging was used to highlight the magnetic properties of the functionalized nanoparticles obtained.     

Fluorescence Modified Chitosan-Coated Magnetic Nanoparticles for High-Efficient Cellular Imaging

Labeling of cells with nanoparticles for living detection is of interest to various biomedical applications. In this study, novel fluorescent/magnetic nanoparticles were prepared and used in high-efficient cellular imaging. The nanoparticles coated with the modified chitosan possessed a magnetic oxide core and a covalently attached fluorescent dye. We evaluated the feasibility and efficiency in labeling cancer cells (SMMC-7721) with the nanoparticles. The nanoparticles exhibited a high affinity to cells, which was demonstrated by flow cytometry and magnetic resonance imaging. The results showed that cell-labeling efficiency of the nanoparticles was dependent on the incubation time and nanoparticles’ concentration. The minimum detected number of labeled cells was around 10⁴ by using a clinical 1.5-T MRI imager. Fluorescence and transmission electron microscopy instruments were used to monitor the localization patterns of the magnetic nanoparticles in cells. These new magneto-fluorescent nanoagents have demonstrated the potential for future medical use.     

Folate and iron difunctionalized multiwall carbon nanotubes as dual-targeted drug nanocarrier to cancer cells

A nanomaterial, folate and iron difunctionalized multiwall carbon nanotube (FA-MWCNT@Fe), has been synthesized by conjugating folate and iron nanoparticles with oxidized multi-walled carbon nanotubes, and applied as a dual-targeted drug nanocarrier to deliver doxorubicin into HeLa cells with the assistance of an external magnetic field. The prepared FA-MWCNT@Fe was characterized by X-ray diffraction, transmission electron microscopy and infrared spectroscopy. This nanocarrier has a sufficient load capacity (doxorubicin/FA-MWCNT@Fe, 32 μg/mg) and a prolonged release property controlled by near infrared radiation. It also demonstrated both biologically (active) and magnetically (passive) targeting capabilities toward HeLa cells in vitro with ca. 6-fold higher delivery efficiency of doxorubicin than free doxorubicin.     

PEG-templated mesoporous silica nanoparticles exclusively target cancer cells

Mesoporous silica nanoparticles (MSNs) have been proposed as DNA and drug delivery carriers, as well as efficient tools for fluorescent cell tracking. The major limitation is that MSNs enter cells regardless of a target-specific functionalization. Here we show that non functionalized MSNs, synthesized using a PEG surfactant-based interfacial synthesis procedure, do not enter cells, while a highly specific, receptor mediated, cellular internalization of folic acid (FOL) grafted MSNs (MSN-FOL), occurs exclusively in folate receptor (FR) expressing cells. Neither the classical clathrin pathway nor macropinocytosis is involved in the MSN endocytic process, while fluorescent MSNs (MSN-FITC) enter cells through aspecific, caveolae-mediated, endocytosis. Moreover, internalized particles seem to be mostly exocytosed from cells within 96 h. Finally, cisplatin (Cp) loaded MSN-FOL were tested on cancerous FR-positive (HeLa) or normal FR-negative (HEK293) cells. A strong growth arrest was observed only in HeLa cells treated with MSN-FOL-Cp. The results presented here show that our mesoporous nanoparticles do not enter cells unless opportunely functionalized, suggesting that they could represent a promising vehicle for drug targeting applications.     

Stability and cytotoxicity study of NiFe2O4 nanocomposites synthesized by co-precipitation and subsequent thermal annealing

In this article, NiFe₂O₄ nanoparticles (NPs) were prepared by co-precipitation method with subsequent thermal annealing leading to obtainment NPs with average sizes of 78 nm. Structure and magnetic analysis were performed by X-ray diffraction, transmission electron microscopy, Mössbauer spectroscopy and vibrating sample magnetometry techniques. Stability of NiFe₂O₄ NPs was evaluated in PBS solution during 20 days. The toxicity of prepared NPs was evaluated in vitro using different cancer cell lines: HeLa (cervical cancer cell), PC-3 (prostate cancer cell). Fibroblasts like cells of L929 obtained from subcutaneous adipose tissue of mouse were used as normal cells. Results indicate successful synthesis of NiFe₂O₄ NPs that exhibit low cytotoxicity in concentration range from 1 to 100 μg/ml. Presented physical and biological results indicate the possibility of application investigated magnetic nanoparticles in hyperthermia, targeted drug delivery, magnetic resonance imaging or cell separation.     

Folate-encoded and Fe3O4-loaded polymeric micelles for dual targeting of cancer cells

Diblock copolymers of poly(ethylene glycol) (PEG) and poly(?-caprolactone) (PCL) bearing a tumor-targeting ligand, folate, were self-assembled into micelles. Superparamagnetic iron oxide (SPIO) nanoparticles and an anticancer drug doxorubicin (DOX) were coencapsulated within the micelles less than 100 nm in diameters. These SPIO-DOX-loaded micelles were superparamagnetic at room temperature, but turned ferrimagnetic at 10 K, consistent with magnetic properties of primary SPIO nanoparticles. Cell culture experiments demonstrated the potential of these polymeric micelles as an effective dual targeting nanoplatform for the delivery of anticancer drugs. Folate attachment to micelles resulted in the recognition of the micelles by tumor cells over-expressing folate receptors, leading to facilitation in cellular uptake of micelles, and the transport efficiency of the SPIO-loaded and folate-functionalized micelles into the tumor cells can be further enhanced by applying an external magnetic field to the cells.     

Development and Screening of a Series of Antibody‐Conjugated and Silica‐Coated Iron Oxide Nanoparticles for Targeting the Prostate‐Specific Membrane Antigen

The prostate‐specific membrane antigen (PSMA) is an established target for the delivery of cancer therapeutic and imaging agents due to its high expression on the surface of prostate cancer cells and within the neovasculature of other solid tumors. Here, we describe the synthesis and screening of antibody‐conjugated silica‐coated iron oxide nanoparticles for PSMA‐specific cell targeting. The humanized anti‐PSMA antibody, HuJ591, was conjugated to a series of nanoparticles with varying densities of polyethylene glycol and primary amine groups. Customized assays utilizing iron spectral absorbance and enzyme‐linked immunoassay (ELISA) were developed to screen microgram quantities of nanoparticle formulations for immunoreactivity and cell targeting ability. Antibody and PSMA‐specific targeting of the optimized nanoparticle was evaluated using an isogenic PSMA‐positive and PSMA‐negative cell line pair. Specific nanoparticle targeting was confirmed by iron quantification with inductively coupled plasma mass spectrometry (ICP‐MS). These methods and nanoparticles support the promise of targeted theranostic agents for future treatment of prostate and other cancers.     

Gadolinium‐conjugated FA‐PEG‐PAMAM‐COOH nanoparticles as potential tumor‐targeted circulation‐prolonged macromolecular MRI contrast agents

The aim of research is to develop potential tumor‐targeted circulation‐prolonged macromolecular magnetic resonance imaging (MRI) contrast agents without the use of low molecular gadolinium (Gd) ligands. The contrast agents were based on polymer–metal complex nanoparticles with controllable particle size to achieve the active and passive tumor‐targeted potential. In particular, poly (amidoamine) (PAMAM) dendrimer with 32 carboxylic groups was modified with folate‐conjugated poly (ethyleneglycol) amine (FA‐PEG‐NH₂, M_w: 2 k and 4 kDa). FA‐PEG‐PAMAM‐Gd macromolecular MRI contrast agents were prepared by the complex reaction between the carboxylic groups in PAMAM and GdCl₃. The structure of FA‐PEG‐PAMAM‐COOH was confirmed by nuclear magnetic resonance (¹H‐NMR), Fourier transform infrared (FTIR) spectra, and electrospray ionization mass spectra (ESI‐MS). The mass percentage content of Gd (III) in FA‐PEG‐PAMAM‐Gd was measured by inductively coupled plasma‐atomic emission spectrometer (ICP‐AES). The sizes of these nanoparticles were about 70 nm measured by transmission electron microscopy, suggestion of their passive targeting potential to tumor tissue. In comparison with clinically available small molecular Gadopentetate dimeglumine, FA‐PEG‐PAMAM‐Gd showed comparable cytotoxicity and higher relaxation rate, suggestion of their great potential as tumor‐targeted nanosized macromolecular MRI contrast agents due to the overexpressed FA receptor in human tumor cell surfaces. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Functionalized chitosan with super paramagnetic hybrid nanocarrier for targeted drug delivery of curcumin

Recently, hydrophobically functionalized polymers have been deployed as carriers to improve the encapsulation of hydrophobic drugs. The metal nanocomposites are extensively used to improve the biocompatibility of the formulation and target the drug to the specialized site. In our current study, naphthalene acetate (NAA) was incorporated into the amine group of chitosan to form a hydrophobically functionalized chitosan–NAA drug delivery carrier. The calcium ferrite nanoparticles (CFNP) were embedded in the chitosan–NAA matrix to form a super paramagnetic hybrid nanocarrier for controlled curcumin drug delivery. Various analytical techniques were performed to ensure the functional group modifications, thermal stability, surface nature and morphological behavior of synthesized hybrid carriers. The maximum encapsulation efficiency of 93.6% was obtained under the optimized conditions of drug to chitosan–NAA at 0.1, CFNP to chitosan–NAA at 0.75 and TPP to chitosan–NAA at 1.0 (w/w) ratios, respectively, by adapting Taguchi method. Drug release studies were conducted to determine the effect of pH, drug loading concentrations and magnetic field responses. The drug release data were fitted to various kinetic release models to understand the drug release mechanism. The biocompatibility of the hybrid material was tested using L929 mouse fibroblast cells. The cytotoxicity test against breast cancer cells (MCF-7) was also performed to study the anticancer property of the hybrid paramagnetic material. The prepared curcumin-loaded chitosan–NAA/CFNP was very active against cancer cells in comparison to the normal cells. The results confirmed the applicability of the hybrid nanocarriers in cancer cell-targeted drug delivery.     

Transferrin-Decorated Niosomes with Integrated InP/ZnS Quantum Dots and Magnetic Iron Oxide Nanoparticles: Dual Targeting and Imaging of Glioma

The development of multifunctional nanoscale systems that can mediate efficient tumor targeting, together with high cellular internalization, is crucial for the diagnosis of glioma. The combination of imaging agents into one platform provides dual imaging and allows further surface modification with targeting ligands for specific glioma detection. Herein, transferrin (Tf)-decorated niosomes with integrated magnetic iron oxide nanoparticles (MIONs) and quantum dots (QDs) were formulated (PEGNIO/QDs/MIONs/Tf) for efficient imaging of glioma, supported by magnetic and active targeting. Transmission electron microscopy confirmed the complete co-encapsulation of MIONs and QDs in the niosomes. Flow cytometry analysis demonstrated enhanced cellular uptake of the niosomal formulation by glioma cells. In vitro imaging studies showed that PEGNIO/QDs/MIONs/Tf produces an obvious negative-contrast enhancement effect on glioma cells by magnetic resonance imaging (MRI) and also improved fluorescence intensity under fluorescence microscopy. This novel platform represents the first niosome-based system which combines magnetic nanoparticles and QDs, and has application potential in dual-targeted imaging of glioma.     

Quantitative Analysis of PMLA Nanoconjugate Components after Backbone Cleavage

Multifunctional polymer nanoconjugates containing multiple components show great promise in cancer therapy, but in most cases complete analysis of each component is difficult. Polymalic acid (PMLA) based nanoconjugates have demonstrated successful brain and breast cancer treatment. They consist of multiple components including targeting antibodies, Morpholino antisense oligonucleotides (AONs), and endosome escape moieties. The component analysis of PMLA nanoconjugates is extremely difficult using conventional spectrometry and HPLC method. Taking advantage of the nature of polyester of PMLA, which can be cleaved by ammonium hydroxide, we describe a method to analyze the content of antibody and AON within nanoconjugates simultaneously using SEC-HPLC by selectively cleaving the PMLA backbone. The selected cleavage conditions only degrade PMLA without affecting the integrity and biological activity of the antibody. Although the amount of antibody could also be determined using the bicinchoninic acid (BCA) method, our selective cleavage method gives more reliable results and is more powerful. Our approach provides a new direction for the component analysis of polymer nanoconjugates and nanoparticles.     

Development of biocompatible NaGdF4: Er3+, Yb3+ upconversion nanoparticles used as contrast agents for bio‐imaging

Upconversion nanoparticles with special fluorescence and magnetic properties have been considered an alternative contrast agent for multiple bio‐imaging techniques. It is important to understand the effects of the surface properties and dosage of upconversion nanoparticles on both the magnetic resonance (MRI) image and the photoluminescence spectrum. Here, NaGdF₄: Er³⁺, Yb³⁺ upconversion nanoparticles (UCNPs) modified with amine functional group were produced through a one‐pot thermal decomposition. The average length of the cubic UCNPs is estimated at 53 ±13 nm. The effect of the dosage of amine modified UCNPs on the MRI image is investigated. The T₁ and T₂ relaxivities of the amine modified UCNPs in agarose gel at 3 T are r₁ = 6.79 ±0.14 and r₂ = 17.0 ±0.18 (mmol/L)^?1 s^?1, which are comparable to the relaxivities of commercially available MRI contrast agents. In addition, the photoluminescence of the amine modified UCNPs at low concentrations < 150 µg/mL are further investigated with the excitation wavelength (λ_ex) at 980 nm. The internalization of the amine modified UCNPs cultured with human umbilical vascular endothelial cells (HUVEC) is observed by the fluorescence imaging. Meanwhile, T₁‐weighted MRI imaging of HUVEC cells treated with amine modified UCNPs at 10 µg/mL can be obtained. No significant toxic effect on cells is found when the concentration of the amine modified UCNPs is < 300 µg/mL. This study indicates that a low concentration of amine‐modified NaGdF₄: Er³⁺, Yb³⁺ UCNPs can be used as the contrast agent for both fluorescence imaging and magnetic resonance imaging.     

Carboxymethyl chitosan-folic acid-conjugated Fe3O4@SiO2 as a safe and targeting antitumor nanovehicle in vitro

A synthetic method to prepare a core-shell-structured Fe₃O₄@SiO₂ as a safe nanovehicle for tumor cell targeting has been developed. Superparamagnetic iron oxide is encapsulated inside nonporous silica as the core to provide magnetic targeting. Carboxymethyl chitosan-folic acid (OCMCS-FA) synthesized through coupling folic acid (FA) with OCMCS is then covalently linked to the silica shell and renders new and improved functions because of the original biocompatible properties of OCMCS and the targeting efficacy of FA. Cellular uptake of the nanovehicle was assayed by confocal laser scanning microscope using rhodamine B (RB) as a fluorescent marker in HeLa cells. The results show that the surface modification of the core-shell silica nanovehicle with OCMCS-FA enhances the internalization of nanovehicle to HeLa cells which over-express the folate receptor. The cell viability assay demonstrated that Fe₃O₄@SiO₂-OCMCS-FA nanovehicle has low toxicity and can be used as an eligible candidate for drug delivery system. These unique advantages make the prepared core-shell nanovehicle promising for cancer-specific targeting and therapy.     

Water-dispersible multiwalled carbon nanotube/iron oxide hybrids as contrast agents for cellular magnetic resonance imaging

Novel magnetic resonance imaging (MRI) contrast agents composed of multiwalled carbon nanotubes decorated with magnetic iron oxide nanoparticles were explored. They were functionalized with multilayer polyelectrolytes through layer-by-layer assembling and were shown to be hydrophilic, biocompatible, and have a high MRI contrast. A targeted ligand folic acid was chemically bonded to the functionalized nanotubes for specific targeting and imaging of cancer cells in MRI. The results demonstrate that the material can be used as ideal targeted imaging agents and is sufficient to obtain strong MRI contrast.     

Dual-modal fluorescent/magnetic bioprobes based on small sized upconversion nanoparticles of amine-functionalized BaGdF5:Yb/Er

A new type of BaGdF(5):Yb/Er nanoprobe for dual-modal fluorescent and magnetic resonance imaging (MRI) is demonstrated. Water soluble and amine-functionalized BaGdF(5):Yb/Er nanoparticles (NPs) with average size of about 10 nm were synthesized by a facile one-pot hydrothermal method. The in vitro up-converted emission of BaGdF(5):Yb/Er NPs is observed in HeLa cells with near-infrared excitation at 980 nm and served as a fluorescent label. In addition, the cytotoxicity assay in HeLa cells shows low cell toxicity of the amine-functionalized BaGdF(5):Yb/Er NPs. Moreover, these BaGdF(5) NPs exhibit excellent intrinsic paramagnetic properties and enhanced T(1)-weighted MRI images with increased concentrations of BaGdF(5) NPs. Therefore, these results suggest that the amine-functionalized BaGdF(5) NPs with an optimized size and low cell toxicity are promising dual-modal bioprobes for optical bioimaging and MRI.     

Chemically modifiable fluorinated copolymer nanoparticles for 19F‐MRI contrast enhancement

Recently there has been interest in developing imaging contrast media for magnetic resonance imaging (MRI) that contain biologically rare, magnetically active nuclei such as fluorine. In principle, fluorinated contrast agents can be used to generate highly selective ¹⁹F magnetic resonance images that can be superimposed over complimentary ¹H magnetic resonance images to provide an anatomical context for the fluorinated contrast agent. Additionally, nanoparticles can be made to target various pathological sites via active and passive targeting mechanisms. In this study, fluorinated nanoparticles were produced using a free radical polymerization of vinyl formamide monomers with two different fluorinated monomers. The nanoparticles showed a clear, single ¹⁹F‐NMR signal. Additionally, surface amide groups were hydrolyzed to primary amines to yield additional surface reactivity. Fluorinated nanoparticles produced using a free‐radial polymerization method yield a new nanoparticle for ¹⁹F‐MRI applications with potential for facile functionalization. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Facile synthesis of folate-conjugated magnetic/fluorescent bifunctional microspheres

In this paper, we investigated the functional imaging properties of magnetic microspheres composed of magnetic core and CdTe quantum dots in the silica shell functionalized with folic acid (FA). The preparation procedure included the preparation of chitosan-coated Fe₃O₄ nanoparticles (CS-coated Fe₃O₄ NPs) prepared by a one-pot solvothermal method, the reaction between carboxylic and amino groups under activation of NHS and EDC in order to obtain the CdTe-CS-coated Fe₃O₄ NPs, and finally the growth of SiO₂ shell vent the photoluminescence (PL) quenching via a Stöber method (Fe₃O₄-CdTe@SiO₂). Moreover, in order to have a specific targeting capacity, the magnetic and fluorescent bifunctional microspheres were synthesized by bonding of SiO₂ shell with FA molecules via amide reaction (Fe₃O₄-CdTe@SiO₂-FA). The morphology, size, chemical components, and magnetic property of as-prepared composite nanoparticles were characterized by ultraviolet-visible spectroscopy, fluorescent spectroscopy, Fourier transform infrared spectroscopy (FTIR), X-ray powder diffraction (XRD), scanning transmission electron microscopy (SEM), transmission electron microscopy (TEM), thermogravimetric analysis (TGA), and vibrating sample magnetometer (VSM), respectively. The results show that the magnetic and fluorescent bifunctional microspheres have strong luminescent which will be employed for immuno-labeling and fluorescent imaging of HeLa cells.     

Studies on Preparation of Photosensitizer Loaded Magnetic Silica Nanoparticles and Their Anti-Tumor Effects for Targeting Photodynamic Therapy

Abstract  As a fast developing alternative of traditional therapeutics, photodynamic therapy (PDT) is an effective, noninvasive, nontoxic therapeutics for cancer, senile macular degeneration, and so on. But the efficacy of PDT was compromised by insufficient selectivity and low solubility. In this study, novel multifunctional silica-based magnetic nanoparticles (SMNPs) were strategically designed and prepared as targeting drug delivery system to achieve higher specificity and better solubility. 2,7,12,18-Tetramethyl-3,8-di-(1-propoxyethyl)-13,17-bis-(3-hydroxypropyl) porphyrin, shorted as PHPP, was used as photosensitizer, which was first synthesized by our lab with good PDT effects. Magnetite nanoparticles (Fe₃O₄) and PHPP were incorporated into silica nanoparticles by microemulsion and sol–gel methods. The prepared nanoparticles were characterized by transmission electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy and fluorescence spectroscopy. The nanoparticles were approximately spherical with 20–30 nm diameter. Intense fluorescence of PHPP was monitored in the cytoplasm of SW480 cells. The nanoparticles possessed good biocompatibility and could generate singlet oxygen to cause remarkable photodynamic anti-tumor effects. These suggested that PHPP-SMNPs had great potential as effective drug delivery system in targeting photodynamic therapy, diagnostic magnetic resonance imaging and magnetic hyperthermia therapy. Graphical Abstract   Novel multifunctional photosensitizer loaded magnetic silica nanoparticles were strategically prepared with low toxicity, good biocompatibility and remarkable photodynamic anti-tumor efficacy. The nanoparticles were believed to be of great value as drug delivery system in targeting photodynamic therapy, diagnostic magnetic resonance imaging and magnetic hyperthermia therapy.