An update on strategies for optimizing polymer-lipid hybrid nanoparticle-mediated drug delivery: exploiting transformability and bioactivity of PLN and harnessing intracellular lipid transport mechanism.

INTRODUCTION: Polymer-lipid hybrid nanoparticle (PLN) is an emerging nanoplatform with distinct properties and functionalities from other nanocarrier systems. PLN can be optimized to overcome various levels of drug delivery barriers to achieve desired therapeutic outcomes via rational selection of polymer and lipid combinations based on a thorough understanding of their properties and interactions with therapeutic agents and biological systems. AREAS COVERED: This review provides an overview of PLN including the motive and history of PLN development, types of PLN, preparation methods, attestations of their versatility, and design strategies to circumvent various barriers for increasing drug delivery accuracy and efficiency. It also highlights recent advances in PLN design including: rationale selection of polymer and lipid components to achieve spatiotemporal drug targeting and multi-targeted cascade drug delivery; utilizing the intracellular lipid transport mechanism for active targeting to desired organelles; and harnessing bioreactive lipids and polymers to magnify therapeutic effects. EXPERT OPINION: A thorough understanding of properties of PLN components and their biofate is important for enhancing disease site targeting, deep tumor tissue penetration, cellular uptake, and intracellular trafficking of PLN. For futuristic PLN development, active lipid transport and dual functions of lipids and polymers as both nanocarrier material and pharmacological agents can be further explored.

Remodeling Tumor Immune Microenvironment by Using Polymer-Lipid-Manganese Dioxide Nanoparticles with Radiation Therapy to Boost Immune Response of Castration-Resistant Prostate Cancer.

Despite substantial progress in the treatment of castration-resistant prostate cancer (CRPC), including radiation therapy and immunotherapy alone or in combination, the response to treatment remains poor due to the hypoxic and immunosuppressive nature of the tumor microenvironment. Herein, we exploited the bioreactivity of novel polymer-lipid manganese dioxide nanoparticles (PLMDs) to remodel the tumor immune microenvironment (TIME) by increasing the local oxygen levels and extracellular pH and enhancing radiation-induced immunogenic cell death. This study demonstrated that PLMD treatment sensitized hypoxic human and murine CRPC cells to radiation, significantly increasing radiation-induced DNA double-strand breaks and ultimately cell death, which enhanced the secretion of damage-associated molecular patterns, attributable to the induction of autophagy and endoplasmic reticulum stress. Reoxygenation via PLMDs also polarized hypoxic murine RAW264.7 macrophages toward the M1 phenotype, enhancing tumor necrosis factor alpha release, and thus reducing the viability of murine CRPC TRAMP-C2 cells. In a syngeneic TRAMP-C2 tumor model, intravenous injection of PLMDs suppressed, while radiation alone enhanced recruitment of regulatory T cells and myeloid-derived suppressor cells. Pretreatment with PLMDs followed by radiation down-regulated programmed death-ligand 1 and promoted the infiltration of antitumor CD8+ T cells and M1 macrophages to tumor sites. Taken together, TIME modulation by PLMDs plus radiation profoundly delayed tumor growth and prolonged median survival compared with radiation alone. These results suggest that PLMDs plus radiation is a promising treatment modality for improving therapeutic efficacy in radioresistant and immunosuppressive solid tumors.

Brain-Penetrating and Disease Site-Targeting Manganese Dioxide-Polymer-Lipid Hybrid Nanoparticles Remodel Microenvironment of Alzheimer's Disease by Regulating Multiple Pathological Pathways.

Finding effective disease-modifying treatment for Alzheimer's disease remains challenging due to an array of factors contributing to the loss of neural function. The current study demonstrates a new strategy, using multitargeted bioactive nanoparticles to modify the brain microenvironment to achieve therapeutic benefits in a well-characterized mouse model of Alzheimer's disease. The application of brain-penetrating manganese dioxide nanoparticles significantly reduces hypoxia, neuroinflammation, and oxidative stress; ultimately reducing levels of amyloid ß plaques within the neocortex. Analyses of molecular biomarkers and magnetic resonance imaging-based functional studies indicate that these effects improve microvessel integrity, cerebral blood flow, and cerebral lymphatic clearance of amyloid ß. These changes collectively shift the brain microenvironment toward conditions more favorable to continued neural function as demonstrated by improved cognitive function following treatment. Such multimodal disease-modifying treatment may bridge critical gaps in the therapeutic treatment of neurodegenerative disease.

Advances in Nanomedicine Design: Multidisciplinary Strategies for Unmet Medical Needs.

Globally, a rising burden of complex diseases takes a heavy toll on human lives and poses substantial clinical and economic challenges. This review covers nanomedicine and nanotechnology-enabled advanced drug delivery systems (DDS) designed to address various unmet medical needs. Key nanomedicine and DDSs, currently employed in the clinic to tackle some of these diseases, are discussed focusing on their versatility in diagnostics, anticancer therapy, and diabetes management. First-hand experiences from our own laboratory and the work of others are presented to provide insights into strategies to design and optimize nanomedicine- and nanotechnology-enabled DDS for enhancing therapeutic outcomes. Computational analysis is also briefly reviewed as a technology for rational design of controlled release DDS. Further explorations of DDS have illuminated the interplay of physiological barriers and their impact on DDS. It is demonstrated how such delivery systems can overcome these barriers for enhanced therapeutic efficacy and how new perspectives of next-generation DDS can be applied clinically.

Optimizing the Design of Blood-Brain Barrier-Penetrating Polymer-Lipid-Hybrid Nanoparticles for Delivering Anticancer Drugs to Glioblastoma.

PURPOSE: Chemotherapy for glioblastoma multiforme (GBM) remains ineffective due to insufficient penetration of therapeutic agents across the blood-brain barrier (BBB) and into the GBM tumor. Herein, is described, the optimization of the lipid composition and fabrication conditions for a BBB- and tumor penetrating terpolymer-lipid-hybrid nanoparticle (TPLN) for delivering doxorubicin (DOX) to GBM. METHODS: The composition of TPLNs was first screened using different lipids based on nanoparticle properties and in vitro cytotoxicity by using 23 full factorial experimental design. The leading DOX loaded TPLNs (DOX-TPLN) were prepared by further optimization of conditions and used to study cellular uptake mechanisms, in vitro cytotoxicity, three-dimensional (3D) glioma spheroid penetration, and in vivo biodistribution in a murine orthotopic GBM model. RESULTS: Among various lipids studied, ethyl arachidate (EA) was found to provide excellent nanoparticle properties e.g., size, polydispersity index (PDI), zeta potential, encapsulation efficiency, drug loading, and colloidal stability, and highest anticancer efficacy for DOX-TPLN. Further optimized EA-based TPLNs were prepared with an optimal particle size (103.8 ± 33.4 nm) and PDI (0.208 ± 0.02). The resultant DOX-TPLNs showed ~ sevenfold higher efficacy than free DOX against human GBM U87-MG-RED-FLuc cells in vitro. The interaction between the TPLNs and the low-density lipoprotein receptors also facilitated cellular uptake, deep penetration into 3D glioma spheroids, and accumulation into the in vivo brain tumor regions of DOX-TPLNs. CONCLUSION: This work demonstrated that the TPLN system can be optimized by rational selection of lipid type, lipid content, and preparation conditions to obtain DOX-TPLN with enhanced anticancer efficacy and GBM penetration and accumulation.

Exploring the transformability of polymer-lipid hybrid nanoparticles and nanomaterial-biology interplay to facilitate tumor penetration, cellular uptake and intracellular targeting of anticancer drugs.

BACKGROUND: Successful delivery of anticancer drugs to intracellular targets requires different properties of the nanocarrier to overcome multiple transport barriers. However, few nanocarrier systems, to date, possess such properties, despite knowledge about the biological fate of inorganic and polymeric nanocarriers in relation to their fixed size, shape and surface properties. Herein, a polymer-lipid hybrid nanoparticle (PLN) system is described with size and shape transformability and its mechanisms of cellular uptake and intracellular trafficking are studied. METHODS: Pharmaceutical lipids were screened for use in transformable PLN. Mechanisms of cellular uptake and the role of fatty acid-binding proteins in intracellular trafficking of PLN were investigated in breast cancer cells. Intra-tumoral penetration and retention of doxorubicin (DOX) were evaluated by confocal microscopy. RESULTS: The lead PLNs showed time-dependent size reduction and shape change from spherical to spiky shape. This transformability of PLNs and lipid trafficking pathways facilitated intracellular transport of DOX-loaded PLN (DOX-PLN) into mitochondria and nuclei. DOX-PLN significantly increased DOX penetration and retention over free DOX or non-transformable liposomal DOX particles at 4 h post-intravenous administration. CONCLUSION: Transformability of PLN and lipid-biology interplay can be exploited to design new nanocarriers for effective drug delivery to tumor cells and intracellular targets.

Microneedle Systems for Vaccine Delivery: the story so far.

INTRODUCTION: Vaccine delivery via a microneedle (MN) system has been identified as a potential alternative to conventional vaccine delivery. MN can be self-administered, is pain-free and is capable of producing superior immunogenicity. Over the last few decades, significant research has been carried out in this area, and this review aims to provide a comprehensive picture on the progress of this delivery platform. AREAS COVERED: This review highlights the potential role of skin as a vaccine delivery route using a microneedle system, examines recent advancements in microneedle fabrication techniques, and provides an update on potential preclinical and clinical studies on vaccine delivery through microneedle systems against various infectious diseases. Articles for the review study were searched electronically in PubMed, Google, Google Scholar, and Science Direct using specific keywords to cover the scope of the article. The advanced search strategy was employed to identify the most relevant articles. EXPERT OPINION: A significant number of MN mediated vaccine candidates have shown promising results in preclinical and clinical trials. The recent emergence of cleanroom free, 3D or additive manufacturing of MN systems and stability, together with the dose-sparing capacity of the Nanopatch® system, have made this platform, commercially, highly lucrative.

Protective effect of chloroform extract of Stereospermum chelonoides bark against amyloid beta42 induced cell death in SH-SY5Y cells and against inflammation in Swiss albino mice.

Background This study was designed to evaluate the free radical scavenging property of chloroform extract of the bark of Stereospermum chelonoides (SCBC) and to investigate its potential in Alzheimer's disease and inflammation, two oxidative stress related disorders. Methods Preliminary phytochemical analysis and in vitro antioxidant potential of SCBC were evaluated using 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging assay, ferric reducing antioxidant power (FRAP) assay, cupric reducing antioxidant capacity (CUPRAC) and total antioxidant capacity determination assay. Total phenol and total flavonoid contents were also determined. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) based cytotoxicity and cyto-protective assays were performed on human neuroblastoma SH-SY5Y cells. Thioflavin-T assay and caspase activation measurement assay were carried out to elucidate the mechanism of cytoprotection of SCBC observed here. In vivo anti-inflammatory potential was measured using croton oil and xylene induced ear edema tests. Results Phytochemical screening of SCBC revealed the presence of various phytoconstituents. Dose-dependent in vitro antioxidant activity was observed. The extract was enriched in flavonoids and polyphenolic compounds too. SCBC was found to inhibit amyloid-ß peptide 1-42 (Aß42) induced cell death in a dose-dependent manner. Encouraged by the cyto-protective effect, its effects on Aß42 fibrillogenesis and caspase-3 activated apoptosis were observed. SCBC significantly slowed down the Aß42 fibrillogenesis and caspase-3 activation in a concentration-dependent manner indicating its probable mechanism of rendering cyto-protection. SCBC has been able to reduce inflammation significantly in croton oil induced ear edema in both doses. Conclusions Thus, this study could form the basis for further study for the potential use of SCBC in oxidative stress associated cell death and inflammation.

Importance of integrating nanotechnology with pharmacology and physiology for innovative drug delivery and therapy - an illustration with firsthand examples.

Nanotechnology has been applied extensively in drug delivery to improve the therapeutic outcomes of various diseases. Tremendous efforts have been focused on the development of novel nanoparticles and delineation of the physicochemical properties of nanoparticles in relation to their biological fate and functions. However, in the design and evaluation of these nanotechnology-based drug delivery systems, the pharmacology of delivered drugs and the (patho-)physiology of the host have received less attention. In this review, we discuss important pharmacological mechanisms, physiological characteristics, and pathological factors that have been integrated into the design of nanotechnology-enabled drug delivery systems and therapies. Firsthand examples are presented to illustrate the principles and advantages of such integrative design strategies for cancer treatment by exploiting 1) intracellular synergistic interactions of drug-drug and drug-nanomaterial combinations to overcome multidrug-resistant cancer, 2) the blood flow direction of the circulatory system to maximize drug delivery to the tumor neovasculature and cells overexpressing integrin receptors for lung metastases, 3) endogenous lipoproteins to decorate nanocarriers and transport them across the blood-brain barrier for brain metastases, and 4) distinct pathological factors in the tumor microenvironment to develop pH- and oxidative stress-responsive hybrid manganese dioxide nanoparticles for enhanced radiotherapy. Regarding the application in diabetes management, a nanotechnology-enabled closed-loop insulin delivery system was devised to provide dynamic insulin release at a physiologically relevant time scale and glucose levels. These examples, together with other research results, suggest that utilization of the interplay of pharmacology, (patho-)physiology and nanotechnology is a facile approach to develop innovative drug delivery systems and therapies with high efficiency and translational potential.

Diruthenium(ii,iii) metallodrugs of ibuprofen and naproxen encapsulated in intravenously injectable polymer-lipid nanoparticles exhibit enhanced activity against breast and prostate cancer cells.

A unique class of diruthenium(ii,iii) metallodrugs containing non-steroidal anti-inflammatory drug (NSAID), Ru2(NSAID), have been reported to show anticancer activity in glioma models in vitro and in vivo. This work reports the encapsulation of the lead metallodrug of ibuprofen (HIbp), [Ru2(Ibp)4Cl] or RuIbp, and also of the new analogue of naproxen (HNpx), [Ru2(Npx)4Cl] or RuNpx, in novel intravenously (i.v.) injectable solid polymer-lipid nanoparticles (SPLNs). A rationally selected composition of lipids/polymers rendered nearly spherical Ru2(NSAID)-SPLNs with a mean size of 120 nm and zeta potential of about -20 mV. The Ru2(NSAID)-SPLNs are characterized by spectroscopic techniques and the composition in terms of ruthenium-drug species is analyzed by mass spectrometry. The metallodrug-loaded nanoparticles showed high drug loading (17-18%) with ∼100% drug loading efficiency, and good colloidal stability in serum at body temperature. Fluorescence-labeled SPLNs were taken up by the cancer cells in a time- and energy-dependent manner as analyzed by confocal microscopy and fluorescence spectrometry. The Ru2(NSAID)-SPLNs showed enhanced cytotoxicity (IC50 at 60-100 µmol L-1 ) in relation to the corresponding Ru2(NSAID) metallodrugs in breast (EMT6 and MDA-MB-231) and prostate (DU145) cancer cells in vitro. The cell viability of both metallodrug nanoformulations is also compared with those of the parent NSAIDs, HIbp and HNpx, and their corresponding NSAID-SPLNs. In vivo and ex vivo fluorescence imaging revealed good biodistribution and high tumor accumulation of fluorescence-labeled SPLNs following i.v. injection in an orthotopic breast tumor model. The enhanced anticancer activity of the metallodrug-loaded SPLNs in these cell lines can be associated with the advantages of the nanoformulations, assigned mainly to the stability of the colloidal nanoparticles suitable for i.v. injection and enhanced cellular uptake. The findings of this work encourage future in vivo efficacy studies to further exploit the potential of the novel Ru2(NSAID)-SPLN nanoformulations for clinical application.

Design of nanocarriers for nanoscale drug delivery to enhance cancer treatment using hybrid polymer and lipid building blocks.

Polymer-lipid hybrid nanoparticles (PLN) are an emerging nanocarrier platform made from building blocks of polymers and lipids. PLN integrate the advantages of biomimetic lipid-based nanoparticles (i.e. solid lipid nanoparticles and liposomes) and biocompatible polymeric nanoparticles. PLN are constructed from diverse polymers and lipids and their numerous combinations, which imparts PLN with great versatility for delivering drugs of various properties to their nanoscale targets. PLN can be classified into two types based on their hybrid nanoscopic structure and assembly methods: Type-I monolithic matrix and Type-II core-shell systems. This article reviews the history of PLN development, types of PLN, lipid and polymer candidates, fabrication methods, and unique properties of PLN. The applications of PLN in delivery of therapeutic or imaging agents alone or in combination for cancer treatment are summarized and illustrated with examples. Important considerations for the rational design of PLN for advanced nanoscale drug delivery are discussed, including selection of excipients, synthesis processes governing formulation parameters, optimization of nanoparticle properties, improvement of particle surface functionality to overcome macroscopic, microscopic and cellular biological barriers. Future directions and potential clinical translation of PLN are also suggested.

Interactions between DNA and Gemini surfactant: impact on gene therapy: part I.

Nonviral gene therapy using gemini surfactants is a unique approach to medicine that can be adapted toward the treatment of various diseases. Recently, gemini surfactants have been utilized as candidates for the formation of nonviral vectors. The chemical structure of the surfactant (variations in the alkyl tail length and spacer/head group) and the resulting physicochemical properties of the lipoplexes are critical parameters for efficient gene transfection. Moreover, studying the interaction of the surfactant with DNA can help in designing an efficient vector and understanding how transfection complexes overcome various cellular barriers. Part I of this review provides an overview of various types of gemini surfactants designed for gene therapy and their transfection efficiency; and Part II will focus on different novel methods utilized to understand the interactions between the gemini and DNA in a lipoplex.

Interactions between DNA and gemini surfactant: impact on gene therapy: part II.

Nonviral gene delivery, provides distinct treatment modalities for the inherited and acquired diseases, relies upon the encapsulation of a gene of interest, which is then ideally delivered to the target cells. Variations in the chemical structure of gemini surfactants and subsequent physicochemical characteristics of the gemini-based lipoplexes and their impact on efficient gene transfection were assessed in part I, which was published in first March 2016 issue of Nanomedicine (1103). In order to design an efficient vector using gemini surfactants, the interaction of the surfactant with DNA and other components of the delivery system must be characterized, and more critically, well understood. Such studies will help to understand how nonviral transfection complexes, in general, overcome various cellular barriers. The Langmuir-Blodgett monolayer studies, atomic force microscopy, differential scanning calorimetry, isothermal titration calorimetry, small-angle x-ray scattering, are extensively used to evaluate the interaction behavior of gemini surfactants with DNA and other vector components. Part II of this review focuses on the use of these unique techniques to understand their interaction with DNA.

Development of DH-I-180-3 loaded lipid nanoparticle for photodynamic therapy.

Photodynamic therapy (PDT) is a promising noninvasive treatment modality for cancer. Photosensitizer and specific wave length of light are the key component of PDT. DH-I-180-3, a second generation photosensitizer, was incorporated into lipid nanoparticle for simultaneous fluorescent imaging and targeting therapy. Solid lipid nanoparticle (SLN) and nanostructured lipid carriers (NLC) based on poloxamer 188 as surfactant and lecithin as co-surfactant were prepared using solvent evaporation and hot homogenization technique. Stearic acid and Capmul(®) MCM C8 were utilized as solid lipid and liquid lipid, respectively. The particle size of SLN and NLCs was around 200 nm and decreased when a part of stearic acid was replaced with Capmul(®) MCM C8. Drug loading efficacy was significantly enhanced when the percentage amount of liquid lipid increased. All the polydispersity indices of the SLN/NLCs were below 0.3, and displayed a narrow particle size distribution. Zeta potentials of all the lipid nanoparticles were below -30 mV, maintaining sufficient repulsive force and achieving enhanced physical stability. No significant change in the particle size and polydispersity index was observed from lyophilized SLN/NLCs. When the photocytotoxic effects of the formulations were evaluated in MCF-7 cells, GI 50 of SLN was less than half of DH-I-180-3 solution, and NLCs containing either 5 or 15%w/w of Capmul(®) MCM C8 exerted higher cytotoxicity than SLN. The fluorescence microscope images displayed enhanced cellular accumulation of DH-I-180-3 loaded in SLN and NLCs, which was closely correlated with the photocytotoxicity results. It was concluded that the incorporation of DH-I-180-3 into the nanoparticles enhanced their targeting efficacy and improved photocytotoxicity.

Antioxidant and cytotoxic activity of stems of Smilax zeylanica in vitro.

BACKGROUND: Plant-derived phytochemicals consisting of phenols and flavonoids possess antioxidant properties, eventually rendering a lucrative tool to scavenge reactive oxygen species. This study was carried out to evaluate in vitro antioxidant and cytotoxic potential of methanolic extract and petroleum ether extracts of Smilax zeylanica L. stems. METHODS: Phytochemical screening was done following standard procedures. Antioxidant activity was tested using several in vitro assays, viz., 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay, NO assay, H2O2 assay, CUPRAC assay, FRAP assay and total antioxidant capacity assay. Total phenol and flavonoid contents were determined by colorimetric method. Brine shrimp lethality and MTT cell viability assays were used for cytotoxic potential. RESULTS: Preliminary phytochemical study revealed the presence of flavonoids and glycosides in both extracts. Methanolic extract was found to possess stronger antioxidant potential than petroleum ether extracts in all assays. The IC50 value of methanolic extract was 29.14±0.39 µg/mL, 120.30±3.32 µg/mL and 78.41±5.53 µg/mL in DPPH assay, NO assay and H2O2 assay, respectively. Likewise, total phenol [56.78 mg/g gallic acid (GAE)] and flovonoid [125.69 mg/g quercetin equivalents (QE)] were higher in methanolic extract. In cytotoxicity assays, petroleum ether extract showed stronger activity in both brine shrimp lethality (LC50 2.85±0.13 µg/mL) and MTT cell viability assay (IC50 15.49±1.18 µg/mL). CONCLUSIONS: These findings demonstrate that methanolic extracts could be considered as potential sources of natural antioxidant, whereas petroleum ether extracts could be explored for promising anticancer molecules.