Cells Overexpressing Folate Receptors Research Articles

Folic Acid-Decorated Nanocrystals as Highly Loaded Trojan Horses to Target Cancer Cells.

The nanocrystal (NC) technology has become one of the most commonly used strategies for the formulation of poorly soluble actives. Given their large specific surface, NCs are mainly used to enhance the oral absorption of poorly soluble actives. Differently from conventional nanoparticles, which require the use of carrier materials and have limited drug loadings, NCs' drug loading approaches 100% since they are formed of the pure drug and surrounded by a thin layer of a stabilizer. In this work, we report the covalent decoration of curcumin NCs with folic acid (FA) using EDC/NHS chemistry and explore the novel systems as highly loaded "Trojan horses" to target cancer cells. The decorated NCs demonstrated a remarkable improvement in curcumin uptake, exhibiting enhanced growth inhibition in cancer cells (HeLa and MCF7) while sparing healthy cells (J774A.1). Cellular uptake studies revealed significantly heightened entry of FA-decorated NCs into cancer cells compared to unmodified NCs while also showing reduced uptake by macrophages, indicating a potential for prolonged circulation in vivo. These findings underline the potential of NC highly loaded nanovectors for drug delivery and, in particular, for cancer therapies, effectively targeting folate receptor-overexpressing cells while evading interception by macrophages, thus preserving their viability and offering a promising avenue for precise and effective treatments.

Potential applications of Folate-conjugated Chitosan Nanoparticles for Targeted delivery of Anticancer drugs

Folate-conjugated chitosan nanoparticles represent a promising nanoplatform for targeted delivery of anticancer drugs. The nanoparticle carrier can protect the therapeutic agents from degradation and offer the ability to target cancer cells overexpressing folate receptors. This review summarizes recent research progress in synthesizing folate-conjugated chitosan nanoparticles as well as evaluating their potential as targeted drug delivery systems. The chemical conjugation of folic acid to chitosan is first discussed followed by an overview of different techniques for preparation of stable folate-conjugated chitosan nanoparticles less than 200 nm in size. Recent studies loading various anticancer drugs into these nanoparticles and investigating their in vitro cytotoxicity against multiple cancer cell lines are then summarized. The results indicate that folate-conjugated nanoparticles exhibit higher cytotoxicity and targeting efficiency compared to non-conjugated nanoparticles due to receptor-mediated endocytosis. Lastly, future challenges and opportunities are outlined including in vivo investigations to determine the effectiveness, toxicity, and pharmacokinetics of folate-conjugated chitosan nanoparticle systems as well as their potential clinical translation as targeted drug carriers for cancer chemotherapy.

Ultrasensitive Fluorescence Detection and Accurate Colocalization Visualization of Dual-miRNAs in Cancer Cells Based on the Conjugated Chain Reaction of Multifunctional Pentagon DNA Nanostructures.

Herein, a multifunctional pentagon DNA nanostructure (MPDN) was assembled by the hybridization of a circular DNA scaffold containing five different fragments with five diverse DNA oligonucleotides for simultaneous sensitive detection and accurate colocalization imaging of dual-miRNAs in cancer cells. Exactly, the MPDN could specifically and efficiently internalize into folate (FA) receptor-overexpressed cells via specific binding of FA and the FA receptor to distinguish cancer cells from normal cells and transform trace amounts of targets miRNA-21 and miRNA-155 into substantial FAM and Cy5-labeled DNA polymers as the signal probe to generate two remarkable fluorescence emissions, realizing simultaneously sensitive detection of dual-miRNAs. Impressively, compared with traditional small fragment DNA probes with high fluidity, the DNA copolymers with extremely low diffusivity kept it in the originally generated position to achieve the colocalization imaging of dual-miRNAs more accurately for revealing the spatial expression information of dual-miRNAs in tissues and cells. This strategy provided programmable tool to simultaneously detect and accurately colocate dual-miRNAs for understanding normal physiology and the tumor mechanism.

Reactive Oxygen Species and Folate Receptor-Targeted Nanophotosensitizers Composed of Folic Acid-Conjugated and Poly(ethylene glycol)-Chlorin e6 Tetramer Having Diselenide Linkages for Targeted Photodynamic Treatment of Cancer Cells.

Folic acid-conjugated nanophotosensitizers composed of folic acid (FA), poly(ethylene glycol) (PEG) and chlorin e6 (Ce6) tetramer were synthesized using diselenide linkages for reactive oxygen species (ROS)- and folate receptor-specific delivery of photosensitizers. Ce6 was conjugated with 3-[3-(2-carboxyethoxy)-2,2-bis(2-carboxyethoxymethyl)propoxy]propanoic acid (tetra acid, or TA) to make Ce6 tetramer via selenocystamine linkages (TA-sese-Ce6 conjugates). In the carboxylic acid end group of the TA-sese-Ce6 conjugates, FA-PEG was attached again using selenocystamine linkages to make FA-PEG/TA-sese-Ce6 conjugates (abbreviated as FAPEGtaCe6 conjugates). Nanophotosensitizers were fabricated by a dialysis procedure. In the morphological observations, they showed spherical shapes with small diameters of less than 200 nm. Stability of the aqueous FAPEGtaCe6 nanophotosensitizer solution was maintained (i.e., their particle sizes were not significantly changed until 7 days later). When H2O2 was added to the nanophotosensitizer solution, the particle size distribution was changed from a monomodal pattern to a multimodal pattern. In addition, the fluorescence intensity and Ce6 release rate from the nanophotosensitizers were also increased by the addition of H2O2. These results indicated that the nanophotosensitizers had ROS-sensitive properties. In an in vitro cell culture study, an FAPEGtaCe6 nanophotosensitizer treatment against cancer cells increased the Ce6 uptake ratio, ROS generation and light-irradiated cytotoxicity (phototoxicity) compared with Ce6 alone against various cancer cells. When the folic acid was pretreated to block the folate receptors of the Y79 cells and KB cells (folate receptor-overexpressing cells), the intracellular Ce6 uptake, ROS generation and thereby phototoxicity were decreased, while the MCF-7 cells did not significantly respond to blocking of the folate receptors. These results indicated that they could be delivered by a folate receptor-mediated pathway. Furthermore, an in vivo pulmonary metastasis model using Y79 cells showed folate receptor-specific delivery of FAPEGtaCe6 nanophotosensitizers. When folic acid was pre-administered, the fluorescence intensity of the lungs was significantly decreased, indicating that the FAPEGtaCe6 nanophotosensitizers had folate receptor specificity in vitro and in vivo. We suggest that FAPEGtaCe6 nanophotosensitizers are promising candidates for a targeted photodynamic therapy (PDT) approach against cancer cells.

Enhanced Anti-Tumor Effect of Folate-Targeted FA-AMA-hyd-DOX Conjugate in a Xenograft Model of Human Breast Cancer

Folate-aminocaproic acid-doxorubicin (FA-AMA-hyd-DOX) was firstly synthesized by our group. It was indicated that FA-AMA-hyd-DOX was pH-responsive, and had strong cytotoxicity on a folate receptor overexpressing cell line (KB cells) in vitro. The aim of our study was to further explore the potential use of FA-AMA-hyd-DOX as a new therapeutic drug for breast cancer. The cellular uptake and the antiproliferative activity of the FA-AMA-hyd-DOX in MDA-MB-231 cells were measured. Compared with DOX, FA-AMA-hyd-DOX exhibited higher targeting ability and cytotoxicity to FR-positive tumor cells. Subsequently, the tissue distribution of FA-AMA-hyd-DOX was studied, and the result confirmed that DOX modified by FA can effectively increase the selectivity of drugs in vivo. After determining the maximum tolerated dose (MTD) of FA-AMA-hyd-DOX in MDA-MB-231 tumor-bearing nude mice, the antitumor effects and the in vivo safety of FA-AMA-hyd-DOX were systematically evaluated. The data showed that FA-AMA-hyd-DOX could effectively increase the dose of DOX tolerated by tumor-bearing nude mice and significantly inhibit MDA-MB-231 tumor growth in vivo. Furthermore, FA-AMA-hyd-DOX treatment resulted in almost no obvious damage to the mice. All the positive data suggest that FA-targeted FA-AMA-hyd-DOX is a promising tumor-targeted compound for breast cancer therapy.

Targeting Cancer Cells Overexpressing Folate Receptors with New Terpolymer-Based Nanocapsules: Toward a Novel Targeted DNA Delivery System for Cancer Therapy.

Chemotherapeutics represent the standard treatment for a wide range of cancers. However, these agents also affect healthy cells, thus leading to severe off-target effects. Given the non-selectivity of the commonly used drugs, any increase in the selective tumor tissue uptake would represent a significant improvement in cancer therapy. Recently, the use of gene therapy to completely remove the lesion and avoid the toxicity of chemotherapeutics has become a tendency in oncotherapy. Ideally, the genetic material must be safely transferred from the site of administration to the target cells, without involving healthy tissues. This can be achieved by encapsulating genes into non-viral carriers and modifying their surface with ligands with high selectivity and affinity for a relevant receptor on the target cells. Hence, in this work we evaluate the use of terpolymer-based nanocapsules for the targeted delivery of DNA toward cancer cells. The surface of the nanocapsules is decorated with folic acid to actively target the folate receptors overexpressed on a variety of cancer cells. The nanocapsules demonstrate a good ability of encapsulating and releasing DNA. Moreover, the presence of the targeting moieties on the surface of the nanocapsules favors cell uptake, opening up the possibility of more effective therapies.

CYTOTOXIC EVALUATION OF ANTICANCER FOLATE DECORATED CARBOPLATIN LOADED ALBUMIN NANOPARTICLES USING FOLATE RECEPTOR OVEREXPRESSING CELL LINES

Lack of selectivity, toxic side effects and multidrug resistance represent major limitations for chemotherapy treatment against cancer. The non-specific targeting of the chemotherapeutic agents leads to the rapid damage of normal cells. This could be significantly reduced through folate mediated nano-therapeutics which aimed to target cancerous cells. In this study, a folate decorated carboplatin loaded albumin nanoparticles was prepared aiming to successful active targeting of folate receptor overexpressing cancer cells which inconsequence decrease side effects and increase efficacy of carboplatin. The formulation was prepared using desolvation technique, glutaraldehyde as a cross linker, bovine serum albumin as a nanocarrier and folic acid as a targeting ligand. Physical characterization of the formulation was carried out as per of particle size, zeta potential and poly dispersity index (PDI). Results showed (267.29 nm) particles with (- 30.4 mV) potential and (0.069) PDI which confirmed a successful preparation of the formulation. For evaluation of the cytotoxic effect of the suggested formulation against the free form of the Carboplatin, an MTT cytotoxic assay was performed on folate receptor overexpressing cell lines (Caco2, PC3) a human colon cancer cell line and a prostate cancer cell line respectively. Results revealed higher significant efficacy represented by lower the half maximal Inhibitory concentration (IC50) values which gives a new hope for using carboplatin in a more effective and safe way in treatment after further clinical investigations.

Folic Acid Conjugated Nanocarriers for Efficient Targetability and Promising Anticancer Efficacy for Treatment of Breast Cancer: A Review of Recent Updates

Breast cancer (BC) is the commonest cause of cancer deaths among Women. It is known to be caused due to mutations in certain receptors, viz. estrogens or progesterones. The most frequently used conventional treatment strategies against BC include chemotherapy, radiation therapy, and partial or entire mastectomy, however, these strategies are often associated with multiple adverse effects, thus reducing patient compliance. Advancement of nanotechnology in the medical application has been made to enhance the therapeutic effectiveness with a significant reduction in the unintended side-effects associated with incorporated anticancer drugs against cancer. The surface engineering technology of the nanocarriers is more pronounced in delivering the therapeutics specifically to target cells. Consequently, folic acid, a small molecular ligand for the folate receptor overexpressed cells, has shown immense response in treating BC cells. Folic acid conjugated nanocarriers have shown remarkable efficiency in targeting overexpressed folate receptors on the surface of BC cells. Binding of these target-specific folate-conjugated nanocarriers substantially improves the internalization of chemotherapeutics in BC cells, without much exposing the other parts of the body. Simultaneously, these folate-- conjugated nanocarriers provide imaging for regular monitoring of targeted drug delivery systems and their responses to an anticancer therapy. Therefore, this review demonstrates the potential of folate-conjugated nanotherapeutics for the treatment and theranostic approaches against BC along with the significant challenges to anticancer therapy, and the prospective insights into the clinical importance and effectiveness of folate conjugate nanocarriers.

Role of Folic Acid in the Therapeutic Action of Nanostructured Porous Silica Functionalized with Organotin(IV) Compounds Against Different Cancer Cell Lines.

The synthesis, characterization and cytotoxic activity against different cancer cell lines of various mesoporous silica-based materials containing folate targeting moieties and a cytotoxic fragment based on a triphenyltin(IV) derivative have been studied. Two different mesoporous nanostructured silica systems have been used: firstly, micronic silica particles of the MSU-2 type and, secondly, mesoporous silica nanoparticles (MSNs) of about 80 nm. Both series of materials have been characterized by different methods, such as powder X-ray diffraction, X-ray fluorescence, absorption spectroscopy and microscopy. In addition, these systems have been tested against four different cancer cell lines, namely, OVCAR-3, DLD-1, A2780 and A431, in order to observe if the size of the silica-based systems and the quantity of incorporated folic acid influence their cytotoxic action. The results show that the materials are more active when the quantity of folic acid is higher, especially in those cells that overexpress folate receptors such as OVCAR-3 and DLD-1. In addition, the study of the potential modulation of the soluble folate receptor alpha (FOLR1) by treatment with the synthesized materials has been carried out using OVCAR-3, DLD-1, A2780 and A431 tumour cell lines. The results show that a relatively high concentration of folic acid functionalization of the nanostructured silica together with the incorporation of the cytotoxic tin fragment leads to an increase in the quantity of the soluble FOLR1 secreted by the tumour cells. In addition, the studies reported here show that this increase of the soluble FOLR1 occurs presumably by cutting the glycosyl-phosphatidylinositol anchor of membrane FR-α and by the release of intracellular FR-α. This study validates the potential use of a combination of mesoporous silica materials co-functionalized with folate targeting molecules and an organotin(IV) drug as a strategy for the therapeutic treatment of several cancer cells overexpressing folate receptors.

Insights into Nano-Photo-Thermal Therapy of Cancer: The Kinetics of Cell Death and Effect on Cell Cycle

Despite considerable advances in nano-photo-thermal therapy (NPTT), there have been a few studies reporting in-depth kinetics of cell death triggered by such a new modality of cancer treatment. In this study, we aimed to (1) investigate the cell death pathways regulating the apoptotic responses to NPTT; and (2) ascertain the effect of NPTT on cell cycle progression. Folate conjugated gold nanoparticle (F-AuNP) was firstly synthesized, characterized and then assessed to determine its potentials in targeted NPTT. The experiments were conducted on KB nasopharyngeal cancer cells overexpressing folate receptors (FRs), as the model, and L929 normal fibroblast cells with a low level of FRs, as the control. Cytotoxicity was evaluated by MTT assay and the cell death mode (i.e., necrosis or apoptosis) was determined through AnnexinV/FITC-propidium iodide staining. Next, the gene expression profiles of some key apoptotic factors involved in the mitochondrial signaling pathway were investigated using RT-qPCR. Finally, cell cycle phase distribution was investigated at different time points post NPTT using flow cytometric analysis. The obtained results showed that KB cell death following targeted NPTT was greater than that observed for L929 cells. The majority of KB cell death following NPTT was related to apoptosis. RT-qPCR analysis indicated that the elevated expression of Bax along with the depressed expression of Bcl-xL, Survivin and XIAP may involve in the regulation of apoptosis in response to NPTT. Flow cytometric analysis manifested that 16-24 hours after NPTT, the major proportion of KB cells was in the most radiosensitive phases of the cell cycle (G2/M). This study extended the understanding of the signaling pathway involved in the apoptotic response to NPTT. Moreover, the potential effect of NPTT on sensitizing cancer cells to subsequent radiation therapy was highlighted.

Chemical labeling and analysis of sialoglycans

Every cell is covered with a dense layer of glycans, which is termed glycocalyx. The outermost monosaccharide of these glycans is often sialic acid, which are a family of nine-carbon monosaccharides. Sialylated glycans play important roles in various physiological and pathological processes, including pathogen invasion, cancer progress, and immune response. Lectins and antibodies have long been used for labeling and detecting sialylated glycans. However, they suffer from low affinity and poor specificity. In the past decades, metabolic glycan labeling (MGL) has emerged as a powerful tool for probing sialylation in live cells and living animals. In the MGL strategy, unnatural sugars containing a bioorthogonal functional group is metabolically incorporated into sialylated glycans by exploiting the underlying glycan biosynthetic pathway. Subsequent bioorthogonal reactions enable conjugation of sialylated glycans with imaging probes or enrichment tags. In this review, we first give a brief introduction on the history and current progress of MGL and bioorthogonal chemistry. Secondly, we discuss the application of MGL in the studies of dynamic changes and regulation of sialylation in various biological processes. Several examples from our research group on the studies of sialylation dynamics in epithelial-mesenchymal transition (EMT), neuronal stem cell differentiation, and cardiac hypertrophy are presented. By metabolic labeling of sialoglycans with ManNAz during EMT, we observed that cellular sialylation was downregulated during EMT, followed by reversion and upregulation. In neuronal stem cells, metabolic labeling of cell-surface sialoglycans has been exploited to discover cell-surface markers. Sialylation in cardiac hypertrophy was investigated by MGL in intact rat hearts, which revealed upregulation of sialylation during hypertrophy. Thirdly, aiming to expand the applications of MGL, we have developed new methods for protein-specific glycan imaging, cell- and tissue-selective glycan labeling, glycan Raman imaging, and novel unnatural sugars. By combining MGL with site-specific protein labeling, we developed a cis-membrane FRET-based methodology to visualize glycans of specific proteins of interest on live cells. Using the protein-specific glycan imaging technique, we found that sialylation of αXβ2 integrin is important for its activation. To overcome the limitation that MGL lacks cell-type selectivity, we developed the liposome-assisted bioorthogonal reporter (LABOR) strategy, in which azido sialic acid is encapsulated in ligand-targeted liposomes for cell-selective labeling of sialylated glycans via the receptor-mediated endocytosis. We demonstrated the LABOR strategy by selective labeling of sialoglycans in folate receptor-overexpressed cells. LABOR enables targeted imaging of tumor-associated sialoglycans and brain sialoglycans in living mice. Fourthly, novel unnatural sialic acids have been developed for probing specific sialoglycoforms, identifying sialic acid-binding proteins, remodeling cell-surface sialic acid, and bioorthogonal Raman imaging of sialylated glycans. Finally, we give an outlook on future directions of studying sialobiology using these chemical methods.

Resveratrol-loaded folate targeted lipoprotein-mimetic nanoparticles with improved cytotoxicity, antioxidant activity and pharmacokinetic profile.

The aim of present study was to develop folate receptor targeted lipoprotein-mimetic nanoparticles of resveratrol (RSV). Lipoprotein-mimicking nanocarrier (RSV-FA-LNPs) comprising of phosphatidyl choline, cholesterol, stearyl amine and folic acid-tagged bovine serum albumin (FA-BSA) were prepared. Folic acid was conjugated to bovine serum albumin by amide bond at a binding rate of 9.46±0.49 folate molecules per bovine serum albumin. The particle size and entrapment efficiency of the developed nanoparticles was found to be 291.37±3.81nm and 91.96±1.83%, respectively. The in vitro release study depicted that developed nanocarrier prolonged the drug release till 72h in phosphate buffer saline (pH7.4). The anticancer potential of RSV in case of RSV-FA-LNPs was found to be substantially improved against MCF-7 cells overexpressing folate receptors compared to non-targeted nanoparticles. The pharmacokinetics studies after intravenous administration in healthy Wistar rats depicted that lipoprotein mimicking nanoparticles presented the longer circulation time (>48h) compared to free drug which disappeared in few hours (6h). The in vitro and preclinical findings of the present study demonstrated the applicability of lipoprotein mimicking nanocarriers for the safer and effective delivery of bioactives.

Docetaxel delivery using folate-targeted liposomes: in vitro and in vivo studies

Objective(s): Folate-targeted liposomes have been well considered in folate receptor (FR) overexpressing cells including MCF-7 and 4T1 cells in vitro and in vivo. The objective of this study is to design an optimum folate targeted liposomal formulations which show the best liposome cell uptake to tumor cells.Material and Methods: In this study, we prepared and characterized different targeted formulations and a nontargeted form as a control. Physicochemical analysis showed that the liposomes had homogeneous population and appropriate size to accumulate to tumor sites through the enhanced permeation and retention (EPR) mechanism. Moreover, we compared the cell uptake of folate targeted liposomal docetaxel compared to nontargeted liposomes in vitro. Results: The in vitro drug release profile of the formulations at different time points showed none of the formulations did not has burst release. However, targeted liposomes accumulated in tumor tissue in vivo less than nontargeted formulations which could be attributed to their uptake by RES due to relatively greater size of targeted formulations. It is presumable that analyze the biodistribution process at longer time points and the molecular mechanisms behind the tissue accumulation could clear the issue. Conclusion: We conclude that success in vitro studies holds the promise of folate targeting strategy and in vivo study merits further investigations.

Folic acid-modified Laponite®-stabilized Fe3O4 nanoparticles for targeted T2-weighted MR imaging of tumor

In this study, a targeted T2-weighted MR imaging agent based on laponite (LAP) was constructed for cancer cells overexpressing folate receptors. Firstly, LAP stabilized Fe3O4 NPs are synthesized by a controlled co-precipitation route, and then amphiphilic copolymer poly(lactic acid)-poly(ethylene glycol) (PLA-PEG-COOH) is assembled on the surface of LAP/Fe3O4 NPs to provide additional stability, followed by the conjugate of folic acid modified generation 2 polyamidoamine dendrimer (G2-FA) via EDC coupling chemistry. The formed LAP/Fe3O4-PLA-PEG-G2-FA NPs can display good colloidal stability and an enhanced r2 relaxivity of 327.6 mM−1 s−1. In vitro experiments demonstrate that the hybrid nanoparticles are cytocompatible in the studied concentration range, and could specific target cancer cells with FA receptors overexpression. Finally, the xenografted tumor model experiment verifies that LAP/Fe3O4-PLA-PEG-G2-FA NPs can significantly reduce the MR signal of tumor site by specific accumulation, and be metabolized from the mice within 24 h. Therefore, LAP/Fe3O4-PLA-PEG-G2-FA NPs with good biocompatibility, a high r2 relaxivity, and FA targetability show a huge potential as a targeted T2-weighted MR imaging contrast for the early diagnosis of tumors overexpressing FA receptors.

Selectivity Enhancement of Paclitaxel Liposome Towards Folate Receptor-Positive Tumor Cells by Ligand Number Optimization Approach.

The present work aims to develop folate-targeted paclitaxel liposome (F-PTX-LIP), which will selectively target tumor cells overexpressing folate receptor (FR) and leave normal cells. Liposomes were prepared by thin-film hydration method followed by post-insertion of synthesized ligand 1,2-distearoyl-sn-glycero-phosphoethanolamine-polyethyleneglycol 2000-folic acid (DSPE-PEG2000-FA) on the outer surface of the liposome. The synthesized ligand was evaluated for in vivo acute toxicity in Balb/c mice. Developed liposomal formulations were characterized using transmission electron microscopy (TEM) and small-angle neutron scattering (SANS). We have investigated the effect of ligand number on cell uptake and cytotoxicity by confocal laser scanning microscopy (CLSM), competitive inhibition and 3-(4,5-dimethythiazol-2-yl)-2,5-diphenyltetrazoliumbromide (MTT) assay. Compared to lung adenocarcinoma cells (A549), uptake in human ovarian carcinoma cells (SKOV3) was 2.2- and 1.2-fold higher for liposome with 480 and 240 ligand number respectively. Competitive inhibition experiment shows that prior incubation of SKOV3 cells with free folic acid significantly reduced the cell uptake of F-PTX-LIP with 480 ligand number (480 F-PTX-LIP) by 2.6-fold. 480 F-PTX-LIP displays higher cytotoxicity than free drug and PTX liposome. Moreover, it specifically targets the cells with higher folate receptor expression. Optimized 480 F-PTX-LIP formulation can be potentially useful for the treatment of folate receptor-positive tumors.

In vitro anticancer activity of folate-modified docetaxel-loaded PLGA nanoparticles against drug-sensitive and multidrug-resistant cancer cells

BackgroundPoly(lactic-co-glycolic acid) (PLGA) is a biodegradable and biocompatible polymer which is widely used as a matrix to incorporate therapeutic agents. The anticancer activity of targeted folate-modified docetaxel-loaded PLGA nanoparticles (F–NP–Doc) was studied in vitro.MethodsNanoparticles were prepared by a single-emulsion solvent-evaporation technique and characterized by physico-chemical methods. Cell survival was measured by the MTT assay and the sulforhodamine B assay. Folate receptor α expression, particle uptake and apoptosis were assessed by flow cytometry.ResultsFolate-modified docetaxel-loaded PLGA nanoparticles showed high anticancer activity in vitro against HeLa cervical carcinoma cells and MCF7 breast adenocarcinoma cells overexpressing folate receptors. Targeted F–NP–Doc nanoparticles were more active compared to free docetaxel and non-targeted NP–Doc nanoparticles; in contrast, the activity of targeted nanoparticles against human fibroblasts (negative control) was significantly lower. F–NP–Doc particles, like free docetaxel, induced apoptosis in cancer cells. F–NP–Doc, but not unmodified docetaxel-loaded PLGA nanoparticles, reversed multidrug resistance of MCF7R breast adenocarcinoma cells. High antitumor activity of F–NP–Doc has also been proven in in vivo experiments.ConclusionsThe summarized experimental data brought us to the conclusion that the incorporation of docetaxel into the targeted PLGA nanoparticles dramatically improves its selectivity against cancer cells.

Multifunctional Oligonucleotide-Functionalized Conjugated Oligomer Nanoparticles for Targeted Cancer Cell Imaging and Therapy.

A novel and multifunctional oligonucleotide-functionalized conjugated oligomer nanoparticle (CON) is developed for effective cancer cell imaging and therapy by integration of fluorescence imaging, target recognition, photodynamic therapy (PDT), and chemotherapy. The CON itself possesses the high fluorescence emission efficiency for imaging and can generate reactive oxygen species for PDT. Due to its excellent biocompatibility, easy functional modification, and efficient drug loading and release ability, oligonucleotides enable the CON to be functionalized in many forms. For the target recognition, the CONs are functionalized with oligonucleotides labeled with folate molecules, which can specifically bind the CONs to the tumor cells overexpressing folate receptors. Moreover, the designed oligonucleotide on the CON hybridizes with its complementary sequence to form double-stranded DNA, which enables a sequence-specific loading with doxorubicin for chemotherapy. For different situations, the therapy of chemotherapy and PDT can be used solely or combinatorially. Therefore, this study provides a facile strategy for the multifunctional modification of CONs with oligonucleotides and opens a new avenue for targeted cell imaging and tumor treatment.

Mitoxantrone-preloaded water-responsive phospholipid-amorphous calcium carbonate hybrid nanoparticles for targeted and effective cancer therapy.

BackgroundThe application of mitoxantrone (MIT) in cancer therapy has been severely limited by its inherent drawbacks. In addition, effective cancer therapy calls for drug release systems capable of enforcing drug release within cancer cells in response to infinite stimulant with enhanced drug penetration capability.MethodsMIT-preloaded phospholipid-amorphous calcium carbonate hybrid nanoparticles (PL/ACC-MIT) that surface modified with PL shell (containing shielding polymer polyethylene glycol and targeting moiety folic acid) were prepared by a facile solvent-diffusion method.ResultsIt has been proven that the resulting PL/ACC-MIT nanoparticles demonstrated satisfactory stability against various aqueous environments with minimal drug leakage and exerted strong targeting capability but selective preference to the folate receptor-overexpressing cell line. In contrast, once exposed to the enzyme-abundant and acidic environments of cancer cells, the PL/ACC-MIT nanoparticles can readily decompose to facilitate quick drug release and enhanced drug penetration to yield preferable antitumor effect both in vitro and in vivo.ConclusionIn this study, MIT-preloaded water-responsive hybrid nanoparticles with increased stability, targetability, controlled drug release, and enhanced drug penetration were successfully developed, which might be a candidate for targeted and effective cancer therapy.

131I-labeled PEG and folic acid co-functionalized graphene quantum dots for tumor-targeted imaging

In this study, we successfully synthesized polyethylene glycol (PEG) and folic acid (FA) co-functionalized graphene quantum dots (GQDs) to improve the biocompatibility and tumor-targeting ability of GQDs simultaneously, and labeled GQDs–PEG–FA with 131I for biological behavior evaluation. The in vitro properties, biodistribution and SPECT imaging of 131I-GQDs–PEG–FA were investigated. The uptake of 131I-GQDs–PEG–FA at tumor sites can be clearly examined via SPECT imaging, which can ascribe to enhanced permeability and retention effect and active targeting effect of FA to folate receptors. The results indicate that 131I-GQDs–PEG–FA can be used as a radioactive probe for detection of tumor cells overexpressing folate receptor.

Folic Acid-Functionalized Gold Nanorods for Controlled Paclitaxel Delivery: In Vitro Evaluation and Cell Studies.

Short gold nanorods were synthesized (average length 28.08nm, average aspect ratio 3.54), which were functionalized with folic acid (FA) and 8-mercaptooctanoic acid (MOA) or 11-mercaptoundecanoic acid (MDA) and loaded with paclitaxel (PCT). FA was conjugated to the nanorods in order to render them targetable for cancer cells overexpressing folate receptors whereas MOA or MDA was attached on the nanorods in order to generate extra hydrophobic areas for entrapment of hydrophobic drugs such as PCT in the nanorods and in order to provide free carboxylic groups, which would allow for the conjugation of drug or other biofunctional molecules to the nanorods. The functionalized gold nanorods (GNRs-MOA-FA and GNRs-MDA-FA) did not exhibit any significant degree of aggregation in cell culture medium and blood plasma even after a prolonged incubation period of 7days, indicating the adequate colloidal stability of the nanorods in these media. The functionalized nanorods exhibited satisfactory entrapment efficiency (around 40%) for PCT and released less than 25% of their PCT content in phosphate buffer pH 7.4 in 48h. PCT entrapment efficiency was a little higher and PCT release rate a little lower in the GNRs-MOA-FA. Molecular analysis (qPCR) was used to find out that the MDA-MB-231 cancer cell line expresses the folate receptor (FL1R) whereas the MCF-7 cancer cell line does not. The PCT-loaded GNRs-MOA-FA were more cytotoxic than the PCT-loaded GNRs-MOA nanorods against the MDA-MB-231 cells, which probably relates to the higher uptake of the GNRs-MOA-FA nanorods by these cells. The opposite was true in the case of the MCF-7 cells.