Recent Advancement of Nanotheranostics in Cancer Applications.

The field of nanomedicine shows promising implications in the concurrent delivery of therapeutic and diagnostic (theranostics) compounds in a single platform. Nanotheranostics is incredibly promising since it offers simultaneous non-invasive disease detection and treatment together with the exciting ability to track drug release and distribution in real-time, thereby forecasting and evaluating the efficacy of the therapy. The cancer theranostic approach improves the cancer prognosis safely and effectively. Common classes of nanoscale biomaterials, including magnetic nanoparticles, quantum dots, upconversion nanoparticles, mesoporous silica nanoparticles, carbon- based nanoparticles, and organic dye-based nanoparticles, have demonstrated enormous potential for theranostic activity. The need for improved disease detection and enhanced chemotherapeutic treatments, together with realistic considerations for clinically translatable nanomaterials will be key driving factors for theranostic agent research shortly. The developments of precision theranostic nanomaterials are employed in imaging systems like, MRI, PET, and SPECT with multifunctional ability. In this review, different nanoparticles/nanomaterials that are used/developed for theranostic activity are discussed.

Naringenin Nanoformulations for Neurodegenerative Diseases.

Glioblastoma (GBM) is a grade-IV astrocytoma, which is the most common and aggressive type of brain tumor, spreads rapidly and has a life-threatening catastrophic effect. GBM mostly occurs in adults with an average survival time of 15 to 18 months, and the overall mortality rate is 5%. Significant invasion and drug resistance activity cause the poor diagnosis of GBM. Naringenin (NRG) is a plant secondary metabolite byproduct of the flavanone subgroup. NRG can cross the blood-brain barrier and deliver drugs into the central nervous system when conjugated with appropriate nanocarriers and can overcome the challenges associated with gliomas through naringenin-loaded nanoformulations. Here, we discuss several nanocarriers employed as delivery systems, including polymeric nanoparticles, micelles, liposomes, solid lipid nanoparticles (SLNs), nanosuspensions, and nanoemulsions. These naringenin-loaded nanoformulations have been tested in various in vitro and in vivo models and administration routes as a potential treatment for brain disorders. The conclusion from this review is that proper nanoformulations of NRG are a possible therapeutic alternative for the treatment of neurological diseases.

Responsive Role of Nanomedicine in the Tumor Microenvironment and Cancer Drug Resistance.

Cancer remains a major worldwide health challenge. Current studies emphasize the tumor microenvironment that plays a vital role in tumor proliferation, invasion, metastasis, and drug resistance. The tumor microenvironment (TME) supports the cancer cell to evade conventional treatment such as surgery, radiotherapy, and chemotherapy. Moreover, the components of tumor microenvironments have a major contribution towards developing therapy resistance in solid tumors. Therefore, targeting the tumor microenvironment can be a novel approach for achieving advancement in cancer nanomedicine. The recent progress in understanding TME and developing TME-responsive nanoparticles offers a great advantage in treating cancer drug resistance. These nanoparticles are developed in response to TME stimuli such as low pH, redox, and hypoxia improve nanomedicine's pharmacokinetic and therapeutic efficacy. This review discusses the various components of the tumor microenvironment responsible for drug resistance and nanomedicine's role in overcoming it.

Nanoparticle-based CRISPR/Cas Delivery: An Emerging Tactic for Cancer Therapy.

Genome editing arose as a new promising approach for treating numerous intricate ailm ents including cancer. Over the past couple of decades, delivery technologies that have serendipitously been developed using viral vectors are successful to some extent in protein and nucleic acid delivery but their effectiveness still lags due to their efficiency, tissue targeting capabilities, and toxicity which must be further improved. With the infiltration of nanotechnology into every sphere of life, nano-vehicles can be implemented as an ideal modality that can overcome challenges, also can be introspective as new genome editing tools for cancer therapy owing to the safety and efficiency in clinical settings. Such projected substitution can help in developing highly efficacious therapy regimes which are successful in clinical settings. This emerging approach of incorporation of genome editors (CRISPR/Cas) in different nano vehicles and their utility in targeting various aspects of cancer therapy like treatment, diagnostics, modelling has been comprehensively done in this review.

Application of Therapeutic Nanoplatforms as a Potential Candidate for the Treatment of CNS Disorders: Challenges and Possibilities.

Drug delivery to central nervous system (CNS) diseases is one of the most challenging tasks. The innate blood-brain barrier (BBB) and the blood-cerebrospinal fluid (BCSF) barrier create an obstacle to effective systemic drug delivery to the CNS, by limiting the access of drugs to the brain. Nanotechnology-based drug delivery platform offers a potential therapeutic approach for the treatment of neurological disorders. Several studies have shown that nanomaterials have great potential to be used for the treatment of CNS diseases. The nanocarriers have simplified the targeted delivery of therapeutics into the brain by surpassing the BBB and actively inhibiting the disease progression of CNS disorders. The review is an overview of the recent developments in nanotechnology-based drug delivery approaches for major CNS diseases like Alzheimer's disease, Parkinson's disease, ischemic stroke, and Glioblastoma. This review discusses the disease biology of major CNS disorders describing various nanotechnology-based approaches to overcome the challenges associated with CNS drug delivery, focussing on nanocarriers in preclinical and clinical studies for the same. The review also sheds light on the challenges during clinical translation of nanomedicine from bench to bedside. Conventional therapeutic agents used for the treatment of CNS disorders are inadequate due to their inability to cross BBB or BCSF, higher efflux from BBB, related toxicity, and poor pharmacokinetics. The amalgamation of nanotechnology with conventional therapeutic agents can greatly ameliorate the pharmacokinetic problems and at the same time assist in efficient delivery to the CNS.

Curcumin Encapsulated into Biocompatible Co-Polymer PLGA Nanoparticle Enhanced Anti-Gastric Cancer and Anti-Helicobacter Pylori Effect.

BACKGROUND: The current disadvantages (high cost, toxicity, resistance) of chemotherapy for gastric cancer opted people for alternative therapy from natural source. Curcumin (natural product) possess multiple biological activities but low bio-availability limits their uses as therapeutic. The Nano-formulation of curcumin increased the bioavailability and productivity of anti-cancer and anti-bacterial properties. The present study was initiated to determine the anti-cancer and anti-bacterial effect of Nano curcumin against gastric cancer and H. pylori. METHODS: Curcumin loaded PLGA nanoparticles (CUR-NPs) was prepared by single emulsion solvent evaporation method. The MIC were determined using agar dilution method to find the anti-H. Pylori activity of Nano curcumin. The cytotoxicity of Nano curcumin was evaluated by MTT assay and the apoptotic effect (cell cycle arrest and morphology change) was shown by PI staining and microscopy. RESULTS: The MIC of nanocurcumin and curcumin for all four H. pylori strains were 8 µg/ml and 16 µg/ml respectively. The inhibition rate of gastric cancer cells after treatment with curcumin was increased from 6% to 67% for 24h, from 8% to 75% for 48h, from 10% to 83% for 72h. In case of nanocurcumin, the inhibition rate increased from 7% to 69% for 24h, 11% to 87% for 48h and 16% to 97% for 72h. The IC50 of curcumin and Nano-curcumin were 24.20 µM and 18.78 µM respectively for 72 h. The population of cells in sub-G0 population increased from 4.1% in the control group to 24.5% and 57.8% when treated with curcumin and nanocurcumin respectively. After 72h of treatment with nanocurcumin, the apoptotic cells population increased as compared to native curcumin treated cells. CONCLUSION: The Nano curcumin might be used as a potential therapeutics against gastric cancer and H. Pylori. There is need of further in vivo study in order to validate CUR-NPs activity.

Multifunctional Mesoporous Silica Nanoparticles for Cancer Therapy and Imaging.

BACKGROUND: Cancer is a widespread disease and has a high mortality rate. Popular conventional treatment encompasses chemotherapy, radiation and surgical resection. However, these treatments impart lots of toxicity problems to the patients mostly due to their non-selectiveness nature, which invokes drug resistances and severe side-effects. OBJECTIVES: In this regard, nanotechnology has claimed to be a smart technology that provides the system with the ability to target drugs to the specific sites. With the use of nanotechnology, various nanomaterials that are widely used as a drug delivery vehicle are created for biomedical applications. Amongst variously diversified nanovehicles, mesoporous silica nanoparticles (MSNs) have attracted enormous attention due to their structural characteristics, great surface areas, tunable pore diameters, good thermal and chemical stability, excellent biocompatibility along with ease of surface modification. Furthermore, the drug release from MSNs can be tailored through various stimuli response gatekeeper systems. The ordered structure of MSNs is extremely suitable for loading of the high amount of drug molecules with controlled delivery for targeting the cancer tissues via enhanced permeability and retention effect or further with surface modification, it can also be actively targeted by various ligands. METHODS: The review article emphases the common synthetic methods and current advancement of MSNs usages for stimuli response drug delivery, immunotherapy as well as the theranostic ability for cancer. CONCLUSION: Although MSNs are becoming the promising tool for more efficient and safer cancer therapy, however, additional translational studies are required to explore its multifunctional ability in a clinical setting.

Mesoporous Silica Nanoparticles: A Versatile Platform for Biomedical Applications.

BACKGROUND: Nanotechnology-based drug delivery approach has emerged as a promising field, where different kinds of formulations are developed for therapeutic applications. Inflowing of nanomedicine developed through various biomaterials appears to be a game changer in the domain of pharmaceutical and biotechnological industries. Nanomedicines propose to overcome the major constraints of conventional medicine of low solubility and stability, non-adequate pharmacokinetic profiles and side effects. OBJECTIVES: Mesoporous Silica Nanoparticles (MSNs) have garnered significant attention in biomedical applications for its multifunctionality. The porous structure of MSNs provides the opportunity for heavy drug loading, controlled release and ligand functionality. From last decades, a lot of interest has been generated owing to the better drug delivery attributes of MSNs to introduce unique biological effects for its suitable therapeutic application. METHODS: The review article gives an insight into the current advancement of usage of MSNs in drug delivery for cancer, non-cancer and biosensors based biomedical applications along with technology that is protected by patents. CONCLUSION: The future success of MSNs is widened because of their valuable characteristic that easily combines with various functionalities which would display enormous potential translational possibilities.

Enhanced accumulation of curcumin and temozolomide loaded magnetic nanoparticles executes profound cytotoxic effect in glioblastoma spheroid model.

Glioblastomas (GBMs) are highly lethal primary brain tumours. Treatment of these malignant gliomas remains ineffective as these are extremely resistant to chemotherapeutic applications. Furthermore, combination therapy for cancer treatment is becoming more popular because it generates synergistic anticancer effects, by reducing individual drug-related toxicity and associated side effects. Currently, magnetic nanoparticles (MNPs) based drug delivery system has attracted much more attention owing to its intrinsic magnetic properties and drug loading capacity. In the present study, MNPs based drug delivery approach for co-delivering of potent chemotherapeutic drugs such as Curcumin (herbal drug) and Temozolomide (DNA methylating agent) has been implemented. The dual drug loaded MNPs formulations were evaluated in two-dimensional (2-D) monolayer culture and three-dimensional (3-D) tumour spheroid culture of T-98G cells for understanding the therapeutic discrepancy. The dual drug loaded MNPs formulations demonstrated higher cytotoxic effect than single drug loaded MNPs formulations as compared to their corresponding native drugs in 2-D and 3-D culture. The combination index (CI) analysis revealed synergistic mode of action of dual drug loaded MNPs formulations, which was further confirmed by cell death induction assay mediated by acridine orange (AO)/propidium iodide (PI) staining, illustrating higher efficacy of the formulation towards GBM therapy.

The transport of non-surfactant based paclitaxel loaded magnetic nanoparticles across the blood brain barrier in a rat model.

There is much interest in utilizing the intrinsic properties of magnetic nanoparticles (MNPs) for the theranostic approaches in medicine. With an aim to develop a potential therapeutics for glioma treatment, efficacy of aqueous dispersible paclitaxel loaded MNPs (Pac-MNPs) were studied in glioblastoma cell line (U-87). The identified potential receptor, glycoprotein non-metastatic melanoma protein B (GPNMB) overexpressed by glioblastoma cells, was actively targeted using GPNMB conjugated Pac-MNPs in U-87 cells. As blood brain barrier (BBB) is the primary impediment in the treatment of glioblastoma, therefore, an attempt was taken to evaluate the biodistribution and brain uptake of Pac-MNPs in rats. The bioavailability of Pac-MNPs illustrated a prolonged blood circulation in vivo, which demonstrated the presence of significant amounts of drug in rat brain tissues as compared to native paclitaxel. Further, the transmission electron microscopy (TEM) study revealed significant accumulation of the Pac-MNPs in the brain tissues. Being an effective contrast enhancement agent for magnetic resonance imaging (MRI) at tissue levels, the MNPs devoid of any surfactant demonstrated enhanced contrast effect in liver and brain imaging. Hence, the significant prevalence of drugs in the rat brain tissues, in vitro targeting potentiality as well as the augmented contrast effect elicit the non-invasive assessment and theranostic applications of MNPs for brain tumor therapy.

Transferrin-conjugated curcumin-loaded superparamagnetic iron oxide nanoparticles induce augmented cellular uptake and apoptosis in K562 cells.

Superparamagnetic iron oxide nanoparticles are currently used for precise drug delivery and as an image contrast agent. In the present study, the potentiality of curcumin-loaded magnetic nanoparticles (Cur-MNPs) for the treatment of chronic myeloid leukemia (CML) was investigated. For active therapy, transferrin (Tf) ligand was further conjugated to Cur-MNPs, which demonstrated enhanced uptake compared to Cur-MNPs in p210bcr/abl-positive cell line (K562). Cur-MNPs demonstrated greater and sustained anti-proliferative activity in a dose- and time-dependent manner; however, with the advent of a magnetic field the anti-proliferative activity of Cur-MNPs as well as Tf-Cur-MNPs was enhanced due to higher cellular uptake with enhanced cytotoxicity activity. Down-regulation of Bcr-Abl protein activates intrinsic apoptotic pathways for promoting anti-leukemic responses. Our in vitro results advocate potential clinical applications of Cur-MNPs by activating multiple signaling pathways for provoking the anti-leukemic activity.

Long circulating lectin conjugated paclitaxel loaded magnetic nanoparticles: a new theranostic avenue for leukemia therapy.

Amongst all leukemias, Bcr-Abl positive chronic myelogenous leukemia (CML) confers resistance to native drug due to multi drug resistance and also resistance to p53 and fas ligand pathways. In the present study, we have investigated the efficacy of microtubule stabilizing paclitaxel loaded magnetic nanoparticles (pac-MNPs) to ascertain its cytotoxic effect on Bcr-Abl positive K562 cells. For active targeted therapy, pac-MNPs were functionalized with lectin glycoprotein which resulted in higher cellular uptake and lower IC(50) value suggesting the efficacy of targeted delivery of paclitaxel. Both pac-MNPs and lectin conjugated pac-MNPs have a prolonged circulation time in serum suggesting increased bioavailability and therapeutics index of paclitaxel in vivo. Further, the molecular mechanism pertaining to pac-induced cytotoxicity was analyzed by studying the involvement of different apoptotic pathway proteins by immunoblotting and quantitative PCR. Our study revealed simultaneous activation of JNK pathway leading to Bcr-Abl instability and the extrinsic apoptotic pathway after pac-MNPs treatment in two Bcr-Abl positive cell lines. In addition, the MRI data suggested the potential application of MNPs as imaging agent. Thus our in vitro and in vivo results strongly suggested the pac-MNPs as a future prospective theranostic tool for leukemia therapy.

Targeted nutlin-3a loaded nanoparticles inhibiting p53-MDM2 interaction: novel strategy for breast cancer therapy.

AIM: The objective of the present study is to prepare and characterize nutlin-3a loaded polymeric poly(lactide-co-glycolide) nanoparticles (NPs) surface functionalized with transferrin ligand, to deliver the encapsulated drug in a targeted manner to its site of action and to evaluate the efficacy of the nanoformulation in terms of its cellular uptake, cell cytotoxicity, cell cycle arrest, apoptosis and activation of p53 pathway at molecular level in MCF-7 breast cancer cell line. METHOD: Nutlin-3a loaded poly(lactide-co-glycolide) NPs were prepared following the single oil-in-water emulsion method. Physicochemical characterization of the formulation included size and surface charge measurement, transmission electron microscopy characterization, study of surface morphology using scanning electron microscopy, Fourier-transform infrared spectral analysis and in vitro release kinetics studies. Furthermore, targeting ability of the conjugated system was assessed by cellular uptake and cell cytotoxicity studies in an in vitro cell model. Molecular basis of nutlin-3a-mediated p53 activation pathway was investigated by western blot analysis. Inhibition of cell cycle progression and apoptosis was evaluated by flow cytometry. RESULTS: Physiochemical characterization of the formulations revealed that nutlin-3a was efficiently encapsulated in the nanoparticulate system, reaching an encapsulation efficiency of approximately 80% with size of approximately 220 nm and negative zeta potential of approximately -10.4 mV. Higher cellular uptake efficiency of the conjugated system proved the effectiveness of targeted therapy. IC(50) values, as determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium assay, showed superior antiproliferative activity of transferrin-conjugated NPs over unconjugated NPs and native nutlin-3a, owing to enhanced cellular uptake by cancer cells. At the molecular level the conjugated system showed enhanced activation of p53 pathway in comparison to native drug as evident from western blot analysis. Augmented cell cycle arrest and apoptosis was exhibited by the conjugated system. Thus, our results suggest that transferrin-conjugated nutlin-3a loaded NPs could be a potential drug carrier system for targeted delivery of potent anticancer drug nutlin-3a for breast cancer therapy.

Composite polymeric magnetic nanoparticles for co-delivery of hydrophobic and hydrophilic anticancer drugs and MRI imaging for cancer therapy.

Exercising complementary roles of polymer-coated magnetic nanoparticles for precise drug delivery and image contrast agents has attracted significant attention in biomedical applications. The objective of this study was to prepare and characterize magnetic nanoparticles embedded in polylactide-co-glycolide matrixes (PLGA-MNPs) as a dual drug delivery and imaging system capable of encapsulating both hydrophilic and hydrophobic drugs. PLGA-MNPs were capable of encapsulating both hydrophobic and hydrophilic drugs in a 2:1 ratio. Biocompatibility, cellular uptake, cytotoxicity, membrane potential, and apoptosis were carried out in two different cancer cell lines (MCF-7 and PANC-1). The molecular basis of induction of apoptosis was validated by Western blotting analysis. For targeted delivery of drugs, targeting ligand such as Herceptin was used, and such a conjugated system demonstrated enhanced cellular uptake and an augmented synergistic effect in an in vitro system when compared with native drugs. Magnetic resonance imaging was carried out both in vitro and in vivo to assess the efficacy of PLGA-MNPs as contrast agents. PLGA-MNPs showed a better contrast effect than commercial contrast agents due to higher T(2) relaxivity with a blood circulation half-life ∼ 47 min in the rat model. Thus, our results demonstrated the dual usable purpose of formulated PLGA-MNPs toward either, in therapeutics by delivering different hydrophobic or hydrophilic drugs individually or in combination and imaging for cancer therapeutics in the near future.

Toxicogenomics of nanoparticulate delivery of etoposide: potential impact on nanotechnology in retinoblastoma therapy.

To develop a suitable formulation with high entrapment efficiency, etoposide-loaded poly(lactide-co-glycolide) nanoparticles (NPs) were formulated by single emulsion-solvent evaporation method by changing different formulation parameters such as drug loading, choice of organic solvent and percentage of emulsifier polyvinyl alcohol. The NPs showed higher entrapment efficiency, ~86% (with 15% (w/w) drug loading). The physicochemical parameters revealed smooth topology with size range (240-320 nm), a negative zeta potential (~19 mV) and in vitro sustained-release activity (~60% drug release in 40 days). Greater anti-proliferative activity ~100 times was observed with NPs (IC50 = 0.002 µg/ml) than that of native etoposide (IC50 = 0.2 µg/ml) in retinoblastoma cell line (Y-79). These NPs demonstrated greater (G1/S) blocking and decreased mitochondrial membrane potential as measured by flow cytometry. There was upregulation of apoptotic gene activity in NPs than native etoposide, as revealed through microarray analysis. However, this is the first ever report demonstrating the intricate modulation of genetic network affected by NPs. Collectively, these results suggest that etoposide-loaded NPs could be potentially useful as a novel drug delivery system for retinoblastoma in the future. FigureNanoparticle-mediated etoposide delivery promotes apoptosis through upregulating several apoptotic inducer genes.

Curcumin-encapsulated MePEG/PCL diblock copolymeric micelles: a novel controlled delivery vehicle for cancer therapy.

AIM: To develop a suitable formulation of curcumin-encapsulated methoxy poly(ethylene glycol) (MePEG)/poly-epsilon-caprolactone (PCL) diblock copolymeric micelle by varying the copolymer ratio, for achieving small sized micelles with high encapsulation of curcumin. To evaluate the micelle's aqueous solubility and stability, efficiency of cellular uptake, cell cytotoxicity and ability to induce apoptosis on pancreatic cell lines. METHOD: Amphiphilic diblock copolymers (composed of MePEG and PCL) were used in various ratios for the preparation of curcumin-encapsulated micelles using a modified dialysis method. Physicochemical characterization of the formulation included size and surface charge measurement, transmission electron microscopy characterization, spectroscopic analysis, stability and in vitro release kinetics studies. The anticancer efficacy of the curcumin-encapsulated micelle formulation was compared with unmodified curcumin in terms of cellular uptake, cell cytotoxicity and apoptosis of pancreatic cell lines MIA PaCa-2 and PANC-1. RESULTS: Physiochemical characterization of the formulations revealed that curcumin was efficiently encapsulated in all formulation of MePEG/PCL micelles; however, a 40:60 MePEG:PCL ratio micelle was chosen for experimental studies owing to its high encapsulation (approximately 60%) with size (approximately 110 nm) and negative zeta potential (approximately -16 mV). Curcumin-encapsulated micelles increased the bioavailability of curcumin due to enhanced uptake (2.95 times more compared with unmodified) with comparative cytotoxic activity (by induction of apoptosis) compared with unmodified curcumin at equimolar concentrations. IC(50) values for unmodified curcumin and curcumin micelles were found to be 24.75 microM and 22.8 microM for PANC-1 and 14.96 microM and 13.85 microM for MIA PaCa-2, respectively. Together the results clearly indicate the promise of a micellar system for efficient solubilization, stabilization and controlled delivery of the hydrophobic drug curcumin for cancer therapy.

Etoposide-loaded biodegradable amphiphilic methoxy (poly ethylene glycol) and poly (epsilon caprolactone) copolymeric micelles as drug delivery vehicle for cancer therapy.

Amphiphilic diblock copolymers composed of methoxy poly ethylene glycol (MePEG) and poly epsilon caprolactone (PCL) were synthesized for the formation of micelles by ring opening mechanism using stannous octoate as a catalyst. The effects of the molecular weight of MePEG and the copolymer ratio on the properties of micelles were investigated by Nuclear Magnetic Resonance ((1)H-NMR), Fourier Transform Infrared Spectroscopy (FT-IR), and Gel Permeation Chromatography (GPC). The diblock copolymers were self-assembled to form micelles and their hydrophobic core was used for the encapsulation of the anti-cancer drug (etoposide) in aqueous solution. The sizes of micelles were less than 250 nm with a narrow size distribution with monodispersed unimodal pattern. Differential Scanning Calorimetric (DSC) thermogram was done for etoposide-loaded micelles to understand the crystalline nature of the drug after entrapment. A drug loading capacity up to 60% (w/w) with an entrapment efficiency of 68% was achieved as determined by reverse phase high performance liquid chromatography (RP-HPLC). In vitro release kinetics showed a biphasic release pattern of etoposide for 2 weeks. The cytotoxic efficacy of the etoposide-loaded micelles demonstrated greater anti-proliferative activity (IC(50) = 1.1 microg/ml) as compared to native drug (IC(50) = 6.3 microg/ml) in pancreatic cancer cell line MIA-PaCa-2. Thus, etoposide-loaded MePEG/PCL block copolymeric micelles can be used as an efficient drug delivery vehicle for pancreatic cancer therapy.

Dual drug loaded superparamagnetic iron oxide nanoparticles for targeted cancer therapy.

The primary inadequacy of chemotherapeutic drugs is their relative non-specificity and potential side effects to the healthy tissues. To overcome this, drug loaded multifunctional magnetic nanoparticles are conceptualized. We report here an aqueous based formulation of glycerol monooleate coated magnetic nanoparticles (GMO-MNPs) devoid of any surfactant capable of carrying high payload hydrophobic anticancer drugs. The biocompatibility was confirmed by tumor necrosis factor alpha assay, confocal microscopy. High entrapment efficiency approximately 95% and sustained release of encapsulated drugs for more than two weeks under in vitro conditions was achieved for different anticancer drugs (paclitaxel, rapamycin, alone or combination). Drug loaded GMO-MNPs did not affect the magnetization properties of the iron oxide core as confirmed by magnetization study. Additionally the MNPs were functionalized with carboxylic groups by coating with DMSA (Dimercaptosuccinic acid) for the supplementary conjugation of amines. For targeted therapy, HER2 antibody was conjugated to GMO-MNPs and showed enhanced uptake in human breast carcinoma cell line (MCF-7). The IC(50) doses revealed potential antiproliferative effect in MCF-7. Therefore, antibody conjugated GMO-MNPs could be used as potential drug carrier for the active therapeutic aspects in cancer therapy.

Targeted epidermal growth factor receptor nanoparticle bioconjugates for breast cancer therapy.

Selective drug delivery is an important approach with great potential for overcoming problems associated with the systemic toxicity and poor bioavailability of antineoplastic drugs. Nanomedicine plays a pivotal role by delivering drugs in a targeted manner to the malignant tumor cells thereby reducing the systemic toxicity of the anticancer drugs. The objective of this study was to prepare and characterize rapamycin loaded polymeric poly(lactide-co-glycolide) (PLGA) nanoparticles (NP) that were surface conjugated with antibodies to epidermal growth factor receptor (EGFR), highly expressed on breast cancer cells, using 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride (EDC) and N-hydroxysuccinimide (NHS) mediated cross linking agents. To potentiate the anticancer efficiency of the formulations, in vitro cytotoxicity of native rapamycin, rapamycin loaded nanoparticles and EGFR antibody conjugated rapamycin loaded nanoparticles (EGFR-Rapa-NPs) were evaluated on malignant MCF 7 breast cancer cell lines. IC(50) doses as determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium (MTT) assay showed the superior antiproliferative activity of EGFR-Rapa-NPs over unconjugated nanoparticles and native rapamycin due to higher cellular uptake on malignant breast cancer cells. Cell cycle arrest and cellular apoptosis induced by the above formulations were confirmed by flow cytometry. Molecular basis of apoptosis studied by western blotting revealed the involvement of a cytoplasmic protein in activating the programmed cell death pathway. Thus it was concluded that EGFR-Rapa-NPs provide an efficient and targeted delivery of anticancer drugs, presenting a promising active targeting carrier for tumor selective therapeutic treatment in near future.