Bone Health Management in the Continuum of Prostate Cancer Disease.

Prostate cancer (PCa) is the second-leading cause of cancer-related deaths in men. PCa cells require androgen receptor (AR) signaling for their growth and survival. Androgen deprivation therapy (ADT) is the preferred treatment for patients with locally advanced and metastatic PCa disease. Despite their initial response to androgen blockade, most patients eventually will develop metastatic castration-resistant prostate cancer (mCRPC). Bone metastases are common in men with mCRPC, occurring in 30% of patients within 2 years of castration resistance and in >90% of patients over the course of the disease. Patients with mCRPC-induced bone metastasis develop lesions throughout their skeleton; the 5-year survival rate for these patients is 47%. Bone-metastasis-induced early changes in the bone that proceed the osteoblastic response in the bone matrix are monitored and detected via modern magnetic resonance and PET/CT imaging technologies. Various treatment options, such as targeting osteolytic metastasis with bisphosphonates, prednisone, dexamethasone, denosumab, immunotherapy, external beam radiation therapy, radiopharmaceuticals, surgery, and pain medications are employed to treat prostate-cancer-induced bone metastasis and manage bone health. However, these diagnostics and treatment options are not very accurate nor efficient enough to treat bone metastases and manage bone health. In this review, we present the pathogenesis of PCa-induced bone metastasis, its deleterious impacts on vital organs, the impact of metastatic PCa on bone health, treatment interventions for bone metastasis and management of bone- and skeletal-related events, and possible current and future therapeutic options for bone management in the continuum of prostate cancer disease.

CD44-targeted, indocyanine green-paclitaxel-loaded human serum albumin nanoparticles for potential image-guided drug delivery.

The use of multifunctional nanomedicines for image-guided drug delivery is currently being universally evaluated as a means of efficiently managing cancers and other diseases. In this study we evaluated the potential of an indocyanine green (ICG) and paclitaxel (PTX) loaded human serum albumin (HSA) nanoparticles that was conjugated with hyaluronic acid for use in image-guided drug delivery targeted to CD44-positive non-small cell lung cancer (NSCLC). Series of NSCLC cell lines were evaluated for the expression of CD44 using both western blot analysis and qRT-PCR and compared to a normal lung fibroblast cell line (MRC-5). Using Fluorescence microscopy and photoacoustic imaging (PA), we explored the ability of these targeted nanoparticles to selectively accumulate in NSCLC cell lines in comparison to MRC-5 and their potential for biomedical imaging towards their use for theranostic application. Results obtained suggest that these targeted nanoparticles have potential for application in both imaging and treatment of NSCLC.

Codelivery of Genistein and miRNA-29b to A549 Cells Using Aptamer-Hybrid Nanoparticle Bioconjugates.

This study aimed to evaluate the anti-cancer effect of a combination therapy of miRNA-29b and genistein loaded in mucin-1 (MUC 1)-aptamer functionalized hybrid nanoparticles in non-small cell lung cancer (NSCLC) A549 cell line. Genistein-miRNA-29b-loaded hybrid nanoparticles (GMLHN) was prepared and characterized. Particle size and zeta potential were measured using photon correlation spectroscopy (PCS). Encapsulation efficiency and loading efficiency were determined using HPLC. Preferential internalization of MUC 1-aptamer functionalized GMLHN by A549 cells was evaluated and compared to normal MRC-5 cells. The ability of GMLHN to downregulate targeted oncoproteins Phosphorylated protein kinase, strain AK, Thymoma (Phosphorylated protein kinase B) (pAKT), Phosphorylated phosphoinositide 3-kinase (p-PI3K), DNA (cytosine-5-)-methyltransferase 3 beta (DNMT3B) and Myeloid Cell Leukemia Sequence 1 (MCL 1) was evaluated using western blot, while antiproliferative effect and ability to initiate apoptosis was also assessed in A549 cells. MUC 1-aptamer functionalized GMLHN nanoparticles were prepared. These nanoparticles were preferentially internalized by A549 cells but less so, in MRC-5 cells. pAKT, p-PI3K, DNMT3B and MCL 1 were efficiently downregulated by these nanoparticles without affecting the levels of AKT and PI3K in A549 cells. GMLHN demonstrated a superior antiproliferative effect compared to individual genistein and miRNA-29b-loaded nanoparticles. Results generated were able to demonstrate that genistein-miRNA-29b-loaded hybrid nanoparticles (GMLHN) could be a potential treatment modality for NSCLC because of the ability of the payloads to attack multiple targets.

Recent advancements in the field of nanotechnology for the delivery of anti-Alzheimer drug in the brain region.

INTRODUCTION: Brain is supposed to be the most complicated part of the body which is very far from the reach of drug moieties. The drug entry in to the brain region depends upon various factors, and among those, the blood-brain-barrier remains the most prominent one. This barrier restricts the entry of almost all the drug and most of the essential biological components like proteins, peptides, etc. and hinders treatment of the CNS disorders. Alzheimer Disease (AD) is one such brain disorder, more specifically a neurodegenerative disorder which primarily affects the older adults. AREAS COVERED: From solubility enhancement to targeted delivery, the nanoparticulate system became the answer for almost all the criticality related to drug delivery. Hence, nanoparticulate drug carrier system has been widely utilizing to remove the hurdles of brain drug delivery. Keeping this in mind, we have underlined the proficiencies of the nanocarrier systems which claim to improve the drug efficacy for the treatment of the AD. EXPERT OPINION: The nanotechnological approaches are highly exploited by the researchers to enhance the drug permeation across the BBB to improve its bioavailability and efficacy by protecting the drug from peripheral degradation. However, still in this area of drug targeting provides vast scope for discoveries towards the enhancement of drug efficacy through surface modifications, site specification, reduced toxicity of the nanocarrier system and so on.

Nose-to-brain drug delivery: An update on clinical challenges and progress towards approval of anti-Alzheimer drugs.

According to the Alzheimer Association Report (2017), Alzheimer's disease (AD) is the 6th primary cause of death in the USA, which affects nearly 5.5 million people. In the year 2017 itself, the cost of AD treatment in the USA has been reported to rise to $259 billion. This statistic shows the severity of the disease in the USA which is very much similar across the globe. On the other hand, the treatment remains limited to a few conventional oral medications (approved by FDA). These are mainly acting superficially from mild to the moderate AD. The therapeutic efficacy of the drug is not only affected by its reduced concentration in the brain owing to the existence of blood-brain-barrier (BBB) but also due to its low brain permeability. In this context, the intranasal (IN) route of drug administration has emerged as an alternative route over the systemic (oral and parenteral) drug delivery to the brain. The delivery of the drug via an IN route offers various advantages over systemic drug delivery system, as it directly delivers the drug into the brain via olfactory route. Presence of drug in the olfactory bulb, in turn, increases the drug bioavailability in the brain and reduces the drug degradation as well as wastage of the drug through` systemic clearance. However, there is also some limitation associated with IN like poor drug permeation through the nasal mucosa and mucociliary clearance. The delivery system various through novel strategies (nano drug carrier system, colloidal carriers, mucoadhesive devices, controlled delivery system, pro-drug, etc.) are adapted to overcome the above-stated limitations. Although, after all, such successful research claims, very few of the nose-to-brain drug delivery of anti-AD drugs have gained market approval due to lack of sufficient clinical evidence. Onzetra Xsail® is one such marketed preparations approved for IN delivery used for the treatment of a brain disorder; migraine. In the field of patents also, no work is found which could present sufficient experimental findings to support its clinical safety profile. It also underlines the fact that majority of work related to the nose-to-brain delivery of anti-AD drugs is limited only up to preclinical studies. In this review article, we have discussed the latest works on various novel formulations loaded with various anti-Alzheimer agents. These agents include galantamine, deferoxamine, tacrine, tarenflurbil, rivastigmine, risperidone, curcumin, quercetin, piperine, insulin, etc. and various peptides towards the development of a promising IN drug delivery system for the treatment of AD. Through this review article, we want to drag the attention of the researchers working in this field towards the challenges and hurdles of practical applicability IN delivery of anti-AD drugs. Moreover, the attention towards the clinical studies will ease the approval process for the administration of anti-Alzheimer drugs via IN route.

Improvement in Therapeutic Efficacy and Reduction in Cellular Toxicity: Introduction of a Novel Anti-PSMA-Conjugated Hybrid Antiandrogen Nanoparticle.

Second generation antiandrogens have improved overall survival for men with metastatic castrate resistant prostate cancer; however, the antiandrogens result in suppression of androgen receptor (AR) activity in all tissues resulting in dose limiting toxicity. We sought to overcome this limitation through encapsulation in a prostate specific membrane antigen (PSMA)-conjugated nanoparticle. We designed and characterized a novel nanoparticle containing an antiandrogen, enzalutamide. Selectivity and enhanced efficacy was achieved through coating the particle with PSMA. The PSMA-conjugated nanoparticle was internalized selectively in AR expressing prostate cancer cells. It did not elicit an inflammatory effect. The efficacy of enzalutamide was not compromised through insertion into the nanoparticle; in fact, lower systemic drug concentrations of enzalutamide resulted in comparable clinical activity. Normal muscle cells were not impacted by the PSMA-conjugated containing antiandrogen. This approach represents a novel strategy to increase the specificity and effectiveness of antiandrogen treatment for men with castrate resistant prostate cancer. The ability to deliver higher drug concentrations in prostate cancer cells may translate into improved clinical end points including overall survival.

Evaluation of MUC1-Aptamer Functionalized Hybrid Nanoparticles for Targeted Delivery of miRNA-29b to Nonsmall Cell Lung Cancer.

The objective of this study was to evaluate the therapeutic efficacy and pharmacokinetic study of mucin1-aptamer functionalized miRNA-29b-loaded hybrid nanoparticles (MAFMILHNs) in lung tumor-bearing SCID mice. MAFMILHNs were manufactured using an isoelectric point based nanotechnology. They were then fully characterized for particle size, loading capacity, zeta potential, and encapsulation efficiency. The ability of MAFMILHNs to downregulate oncoprotein DNMT3B both at the cellular level and in vivo was monitored using Western blot, while the effect of the downregulation of DNMT3B on tumor growth was assessed using bioluminescence. Results indicate that the presence of MUC1-aptamer conjugated to the surface of the nanoparticles enhanced the selective delivery of miRNA-29b to tumor cells and tissues. Further, the downregulation of DNMT3B by MAFMILHNs resulted in the inhibition of tumor growth in mouse models.

siRNA-Encapsulated Hybrid Nanoparticles Target Mutant K-ras and Inhibit Metastatic Tumor Burden in a Mouse Model of Lung Cancer.

There is an unmet need in the development of an effective therapy for mutant K-ras-expressing non-small-cell lung cancer (NSCLC). Although various small molecules have been evaluated, an effective therapy remains a dream. siRNAs have the potential to downregulate mutant K-ras both at the protein and mRNA levels. However, a safe and effective delivery of siRNAs to tumors remains a limitation to their translational application in the treatment of this highly debilitating disease. Here we developed a novel hybrid nanoparticle carrier for effective delivery of anti-mutant K-ras to NSCLC (AKSLHN). The ability of this treatment modality to regress lung tumors in mouse models was evaluated as a monotherapy or as a combination treatment with erlotinib. Further, the toxicity of this treatment modality to healthy tissues was evaluated, along with its ability to elicit immune/inflammatory reactions. The results suggest that this treatment modality is a promising prospect for the treatment of mutant K-ras-expressing NSCLC without any accompanying toxicity. However, further understanding of the cellular-level interaction between AHSLHN and erlotinib needs to be attained before this promising treatment modality can be brought to the bedside.

Aptamer-hybrid nanoparticle bioconjugate efficiently delivers miRNA-29b to non-small-cell lung cancer cells and inhibits growth by downregulating essential oncoproteins.

MicroRNAs (miRNAs) are potentially attractive candidates for cancer therapy. However, their therapeutic application is limited by lack of availability of an efficient delivery system to stably deliver these potent molecules intracellularly to cancer cells while avoiding healthy cells. We developed a novel aptamer-hybrid nanoparticle bioconjugate delivery system to selectively deliver miRNA-29b to MUC1-expressing cancer cells. Significant downregulation of oncoproteins DNMT3b and MCL1 was demonstrated by these MUC1 aptamer-functionalized hybrid nanoparticles in A549 cells. Furthermore, downregulation of these oncoproteins led to antiproliferative effect and induction of apoptosis in a superior version when compared with Lipofectamine 2000. This novel aptamer-hybrid nanoparticle bioconjugate delivery system could potentially serve as a platform for intracellular delivery of miRNAs to cancer cells, hence improving the therapeutic outcome of lung cancer.

Biodistribution and Pharmacokinetics Study of siRNA-loaded Anti-NTSR1-mAb-functionalized Novel Hybrid Nanoparticles in a Metastatic Orthotopic Murine Lung Cancer Model.

Small interfering RNA (siRNA) is effective in silencing critical molecular pathways in cancer. The use of this tool as a treatment modality is limited by lack of an intelligent carrier system to enhance the preferential delivery of this molecule to specific targets in vivo. In the present study, the in vivo behavior of novel anti-NTSR1-mAb-functionalized antimutant K-ras siRNA-loaded hybrid nanoparticles, delivered by i.p. injection to non-small-cell lung cancer in mice models, was investigated and compared to that of a naked siRNA formulation. The siRNA in anti-NTSR1-mAb-functionalized hybrid nanoparticles was preferentially accumulated in tumor-bearing lungs and metastasized tumor for at least 48 hours while the naked siRNA formulation showed lack of preferential accumulation in all of the organs monitored. The plasma terminal half-life of nanoparticle-delivered siRNA was 11 times higher (17-1.5 hours) than that of the naked siRNA formulation. The mean residence time and AUClast were 3.4 and 33 times higher than the corresponding naked siRNA formulation, respectively. High-performance liquid chromatography analysis showed that the hybrid nanoparticle carrier system protected the encapsulated siRNA against degradation in vivo. Our novel anti-NTSR1-mAb-functionalized hybrid nanoparticles provide a useful platform for in vivo targeting of siRNA for both experimental and clinical purposes.

Novel targeted siRNA-loaded hybrid nanoparticles: preparation, characterization and in vitro evaluation.

BACKGROUND: siRNAs have a high potential for silencing critical molecular pathways that are pathogenic. Nevertheless, their clinical application has been limited by a lack of effective and safe nanotechnology-based delivery system that allows a controlled and safe transfection to cytosol of targeted cells without the associated adverse effects. Our group recently reported a very effective and safe hybrid nanoparticle delivery system composing human IgG and poloxamer-188 for siRNA delivery to cancer cells. However, these nanoparticles need to be optimized in terms of particle size, loading capacity and encapsulation efficiency. In the present study, we explored the effects of certain production parameters on particle size, loading capacity and encapsulation efficiency. Further, to make these nanoparticles more specific in their delivery of siRNA, we conjugated anti-NTSR1-mAb to the surface of these nanoparticles to target NTSR1-overexpressing cancer cells. The mechanism of siRNA release from these antiNTSR1-mAb functionalized nanoparticles was also elucidated. RESULTS: It was demonstrated that the concentration of human IgG in the starting nanoprecipitation medium and the rotation speed of the magnetic stirrer influenced the encapsulation efficiency, loading capacity and the size of the nanoparticles produced. We also successfully transformed these nanoparticles into actively targeted nanoparticles by functionalizing with anti-NTSR1-mAb to specifically target NTSR1-overexpressing cancer cells, hence able to avoid undesired accumulation in normal cells. The mechanism of siRNA release from these nanoparticles was elucidated to be by Fickian diffusion. Using flow cytometry and fluorescence microscopy, we were able to confirm the active involvement of NTSR1 in the uptake of these anti-NTSR1-mAb functionalized hybrid nanoparticles by lung adenocarcinoma cells. CONCLUSIONS: This hybrid nanoparticle delivery system can be used as a platform technology for intracellular delivery of siRNAs to NTSR1-overexpressing tumor cells.

Investigation of the stability and cellular uptake of self-associated monoclonal antibody (MAb) nanoparticles by non-small lung cancer cells.

The inability to deliver MAbs to intracellular targets still remains a limitation to their application in cancer therapy and diagnosis. Selective targeting of MAbs to oncoproteins in cancer cells while avoiding their accumulation in normal cells may reduce some of the well-documented adverse effects accompanying antibody therapy. One of the remarkable characteristics of malignant cells is the alteration in the biological properties of the cellular plasma membrane. Taking advantage of this alteration, we hope to selectively deliver self-associated MAb nanoparticles to cancer cells while reducing their accumulation in normal cells. We hypothesized that self-associated MAb nanoparticles can be preferentially taken up by non-small lung cancer cells in comparison to normal cells due to the absence or dysfunction of tight junctions (TJ) in confluent cancer cells and increased permeability of the cancer cell membrane. Self-associated bevacizumab nanoparticles were prepared and characterized for particle size and biochemical stability. Fluorescence microscopy, TEM, and flow cytometry revealed that these bevacizumab nanoparticles were internalized by A549 cells three times more than MRC-5 cells. Macropinocytosis and energy-dependent pathways were elucidated to be involved in their uptake by A549 cells. Further, uptake was by nonspecific interaction with cell membrane. Results obtained from this study suggest that self-associated MAb nanoparticles can be selectively delivered to cancer cells.

Self-associated submicron IgG1 particles for pulmonary delivery: effects of non-ionic surfactants on size, shape, stability, and aerosol performance.

The ability to produce submicron particles of monoclonal antibodies of different sizes and shapes would enhance their application to pulmonary delivery. Although non-ionic surfactants are widely used as stabilizers in protein formulations, we hypothesized that non-ionic surfactants will affect the shape and size of submicron IgG particles manufactured through precipitation. Submicron particles of IgG1 were produced by a precipitation process which explores the fact that proteins have minimum solubility but maximum precipitation at the isoelectric point. Non-ionic surfactants were used for size and shape control, and as stabilizing agents. Aerosol performance of the antibody nanoparticles was assessed using Andersen Cascade Impactor. Spinhaler® and Handihaler® were used as model DPI devices. SEM micrographs revealed that the shape of the submicron particles was altered by varying the type of surfactant added to the precipitating medium. Particle size as measured by dynamic light scattering was also varied based on the type and concentration of the surfactant. The surfactants were able to stabilize the IgG during the precipitation process. Polyhedral, sponge-like, and spherical nanoparticles demonstrated improved aerosolization properties compared to irregularly shaped (>20 µm) unprocessed particles. Stable antibody submicron particles of different shapes and sizes were prepared. Careful control of the shape of such particles is critical to ensuring optimized lung delivery by dry powder inhalation.

The effects of excipients and particle engineering on the biophysical stability and aerosol performance of parathyroid hormone (1-34) prepared as a dry powder for inhalation.

Pulmonary delivery of therapeutic peptides and proteins has many advantages including high relative bioavailability, rapid systemic absorption and onset of action and a non-invasive mode of administration which improves patient compliance. In this study, we investigated the effect of spray-drying (SD) and spray freeze-drying processes on the stability and aerosol performance of parathyroid hormone (PTH) (1-34) microparticles. In this study, the stabilisation effect of trehalose (a non-reducing sugar) and Brij 97 (a non-ionic surfactant) on spray-dried PTH particles was assessed using analytical techniques including circular dichroism (CD), fluorescence spectroscopy, modulated differential scanning calorimetry and an in vitro bioactivity assay. Physical characterisation also included electron microscopy, tap density measurement and laser light diffraction. The aerosol aerodynamic performance of the formulations was assessed using the Andersen cascade impactor. Based on these studies, a formulation for spray freeze-drying was selected and the effects of the two particle engineering techniques on the biophysical stability and aerosol performance of the resulting powders was determined. CD, fluorescence spectroscopy and bioactivity data suggest that trehalose when used alone as a stabilising excipient produces a superior stabilising effect than when used in combination with a non-ionic surfactant. This highlights the utility of CD and fluorescence spectroscopy studies for the prediction of protein bioactivity post-processing. Therefore, a method and formulation suitable for the preparation of PTH as a dry powder was developed based on spray-drying PTH with trehalose as a stabiliser with the bioactivity of SD PTH containing trehalose being equivalent to that of unprocessed PTH.

Controlling the release of proteins/peptides via the pulmonary route.

The inhalation route is seen as the most promising non-invasive alternative for the delivery of proteins; however, the short duration of activity of drugs delivered via this route brought about by the activities of alveolar macrophages and mucociliary clearance means there is a need to develop controlled release system to prolong the activities of proteins delivered to the lung. Polymeric materials such as (D,L)-poly(lactic glycolic acid) (PLGA), chitosan and poly(ethylene glycol) (PEGs) have been used for controlled release of proteins. Other systems such as liposomes and microcrystallization have also proved effective. This chapter gives a more detailed understanding of these techniques and the manufacture of the delivery systems.

Engineering protein particles for pulmonary drug delivery.

Pulmonary delivery of proteins requires particles for delivery to be in the aerodynamic size range 1-5 microm for deep lung deposition. However, the traditional particle size reduction technique of jet-milling normally used for inhalation is not suitable for processing these protein particles because of their lability brought about by the weak physical interactions making up their higher order structures. Advanced techniques such as spray drying, spray freeze drying and the use of supercritical fluid technology have been developed to produce particles in the suitable size range and morphology for deep long deposition without altering the native conformation of these biomolecules. Judicious use of excipients and operating conditions are some of the factors needed for a successful particle design.

Particle engineering techniques for inhaled biopharmaceuticals.

Formulation of biopharmaceuticals for pulmonary delivery is faced with the challenge of producing particles with the optimal properties for deep lung deposition without altering the native conformation of these molecules. Traditional techniques such as milling are continuously being improved while newer and more advanced techniques such as spray drying, spray freeze drying and supercritical fluid technology are being developed so as to optimize pulmonary delivery of biopharmaceuticals. While some of these techniques are quite promising, some are harsh and impracticable. Method scale up, cost-effectiveness and safety issues are important factors to be considered in the choice of a technique. This paper reviews the presently developed techniques for particle engineering biopharmaceuticals.

Prospects of formulating proteins/peptides as aerosols for pulmonary drug delivery.

Formulation of proteins/peptides for therapeutic uses has often posed some challenges to drug formulators. The main problem is the relatively weak forces involved in the native conformation of these proteins and so making them quite labile. Furthermore, their susceptibility to proteolytic enzymes in the gut makes oral administration quite challenging. While various routes like, ocular, transdermal, nasal and buccal have been tried, none of these routes has proved to be a potential alternative to the invasive injection. However, various studies have been performed on the formulation of these proteins as aerosols for pulmonary delivery and promising results have been obtained. This article looks at the prospects of inhaled proteins as a delivery route for systemic activity.