Core–shell-type lipid–polymer hybrid nanoparticles as a drug delivery platform

Flurbiprofen loaded ethosomes - transdermal delivery of anti-inflammatory effect in rat model

Background

Ethosomes have been widely used in Transdermal Drug Delivery System (TDDS) as they increase the permeation of drug across the skin.

Methods

Flurbiprofen loaded vesicular ethosomes were formulated, optimized and characterized for particle size, entrapment efficiency, poly dispersive index (PDI), microscopy using Atomic force microscopy (AFM), Scanning electron microscope (SEM) and Transmission electron microscopy (TEM) and Interaction of drug and excipients were studied using Fourier transform infra-red (FTIR) spectroscopy, Differential scanning colorimetry (DSC), Thermo gravimetric analysis (TGA). Further, ethosomal formulations of flurbiprofen were evaluated for stability study of three months and in vitro drug permeation study was carried out using albino rat skin. In addition, skin irritation test was evaluated by Draize test and in vivo study of prepared formulation was examined through paw edema assay by inducing carrageenan and cold plate method.

Results

Amongst all formulations, EF5 formulation exhibited ideal surface morphology, with maximum entrapment efficiency (95%) with optimal excipient concentration i.e. 200 mg phospholipid and 35% ethanol. The ideal vesicle size was achieved as 162.2 ± 2 nm, with zeta potential − 48.14 ± 1.4 mV with the PDI of 0.341. In-vitro permeation study shows a release of 82.56 ± 2.11 g/cm² in 24 h and transdermal flux was found as 226.1 μg/cm²/h. Cold plate test indicates that the formulation EF5 showed a marked analgesic activity and Carrageenan induced paw edema test indicates that the formulation EF5 inhibits the increase in paw edema. Ethosomal suspension at 4 °C showed maximum stability.

Conclusions

The overall study concluded that this ethosomal approach offers a new delivery system for sustained and targeted delivery for flurbiprofen.

Electronic supplementary material

The online version of this article (10.1186/s12944-019-1064-x) contains supplementary material, which is available to authorized users.

Nano-based approach to combat emerging viral (NIPAH virus) infection

Emergence of new virus and their heterogeneity are growing at an alarming rate. Sudden outburst of Nipah virus (NiV) has raised serious question about their instant management using conventional medication and diagnostic measures. A coherent strategy with versatility and comprehensive perspective to confront the rising distress could perhaps be effectuated by implementation of nanotechnology. But in concurrent to resourceful and precise execution of nano-based medication, there is an ultimate need of concrete understanding of the NIV pathogenesis. Moreover, to amplify the effectiveness of nano-based approach in a conquest against NiV, a list of developed nanosystem with antiviral activity is also a prerequisite. Therefore the present review provides a meticulous cognizance of cellular and molecular pathogenesis of NiV. Conventional as well several nano-based diagnosis experimentations against viruses have been discussed. Lastly, potential efficacy of different forms of nano-based systems as convenient means to shield mankind against NiV has also been introduced.

An update on polymer-lipid hybrid systems for improving oral drug delivery

INTRODUCTION

A promising approach that has recently emerged to overcome the complex biobarriers and interrelated challenges associated with oral drug absorption is to combine the benefits of polymeric and lipid-based nanocarriers within one hybrid system. This multifaceted formulation strategy has given rise to a plethora of polymer-lipid hybrid (PLH) systems with varying nanostructures and biological activities, all of which have demonstrated the ability to improve the biopharmaceutical performance of a wide range of challenging therapeutics.

AREAS COVERED

The multitude of polymers that can be combined with lipids to exert a synergistic effect for oral drug delivery have been identified, reviewed and critically evaluated. Specific focus is attributed to preclinical studies performed within the past 5 years that have elucidated the role and mechanism of the polymer phase in altering the oral absorption of encapsulated therapeutics.

EXPERT OPINION

The potential of PLH systems has been clearly identified; however, improved understanding of the structure-activity relationship between PLH systems and oral absorption is fundamental for translating this promising delivery approach into a clinically relevant formulation. Advancing research within this field to identify optimal polymer, lipid combinations and engineering conditions for specific therapeutics are therefore encouraged.

Flurbiprofen-loaded ethanolic liposome particles for biomedical applications

Present study deals with the preparation, characterization and in-vivo evaluation of flurbiprofen loaded ethanolic liposome which provides predetermined and controlled release of drug through a transdermal drug delivery system. Ethanolic liposomes were prepared by using flurbiprofen, phospholipon 90-G, and ethanol in varied concentration ratio. The prepared ethanolic liposomes were optimized and characterized for particle size, zeta potential, polydispersive index and % entrapment efficiency. FTIR study was performed to analyze the interaction between drug and excipient. To study the thermal behavior of the formulation DSC and TGA were carried out. The surface morphology of ethanolic liposome was performed with the help of SEM, TEM, and AFM. In-vitro drug permeation study of the optimized formulation was carried out using the albino rat skin model and peripheral nociceptive activity was evaluated by writhing assay. In addition, formulations were also inspected for stability study for three months at a different temperature. The optimized formulation EF5 exhibited a particle size of 167.2 ± 3.7 nm with a zeta potential of -51.6 ± 0.2 mV and PDI of 0.209. The optimized formulation showed an ideal surface morphology with a maximum % entrapment efficiency i.e. 93.51 ± 2.1. In-vitro permeation study shows a release of 70.23% in 24 h and transdermal flux was found as 238.2 μg/cm²/h. Writhing assay demonstrate that the optimized formulation decreases the number of writhes and thus shows the peripheral analgesic activity. In stability study, optimized formulation showed maximum stability at 4 °C. These results suggest that transdermal system mediated application of flurbiprofen loaded ethanolic liposome can be considered as an effective way to afford consistent and predictable release of flurbiprofen which could provide beneficial effects in the management of various inflammatory diseases.

Traditional Chinese medicine-combination therapies utilizing nanotechnology-based targeted delivery systems: a new strategy for antitumor treatment

Cancer is a major public health problem, and is now the world’s leading cause of death. Traditional Chinese medicine (TCM)-combination therapy is a new treatment approach and a vital therapeutic strategy for cancer, as it exhibits promising antitumor potential. Nano-targeted drug-delivery systems have remarkable advantages and allow the development of TCM-combination therapies by systematically controlling drug release and delivering drugs to solid tumors. In this review, the anticancer activity of TCM compounds is introduced. The combined use of TCM for antitumor treatment is analyzed and summarized. These combination therapies, using a single nanocarrier system, namely codelivery, are analyzed, issues that require attention are determined, and future perspectives are identified. We carried out a systematic review of >280 studies published in PubMed since 1985 (no patents involved), in order to provide a few basic considerations in terms of the design principles and management of targeted nanotechnology-based TCM-combination therapies.

Lipid-polymer hybrid nanoparticles as a next-generation drug delivery platform: state of the art, emerging technologies, and perspectives

Lipid-polymer hybrid nanoparticles (LPHNPs) are next-generation core-shell nanostructures, conceptually derived from both liposome and polymeric nanoparticles (NPs), where a polymer core remains enveloped by a lipid layer. Although they have garnered significant interest, they remain not yet widely exploited or ubiquitous. Recently, a fundamental transformation has occurred in the preparation of LPHNPs, characterized by a transition from a two-step to a one-step strategy, involving synchronous self-assembly of polymers and lipids. Owing to its two-in-one structure, this approach is of particular interest as a combinatorial drug delivery platform in oncology. In particular, the outer surface can be decorated in multifarious ways for active targeting of anticancer therapy, delivery of DNA or RNA materials, and use as a diagnostic imaging agent. This review will provide an update on recent key advancements in design, synthesis, and bioactivity evaluation as well as discussion of future clinical possibilities of LPHNPs.

An efficient and long-acting local anesthetic: ropivacaine-loaded lipid-polymer hybrid nanoparticles for the control of pain

Purpose

Local anesthetics are used clinically for the control of pain following operation (including gastrointestinal surgery) or for the management of other acute and chronic pain. This study aimed to develop a kind of lipid-polymer hybrid nanoparticles (LPNs), which were constructed using poly(ethylene glycol)-distearoylphosphatidylethanolamine (PEG-DSPE) as the hydrophilic lipid shell and poly-ε-caprolactone (PCL) as the hydrophobic polymeric core.

Methods

Ropivacaine (RPV) was entrapped in the LPNs (RPV-LPNs) and the physicochemical and biochemical properties such as size, zeta potential, drug release, and cytotoxicity were studied. The long-lasting effects and safety aspects of the LPNs were evaluated in vitro and in vivo.

Results

The particle size and zeta potential of RPV-LPNs were 112.3±2.6 nm and −33.2±3.2 mV, with an entrapment efficiency (EE) of 90.2%±3.7%. Ex vivo permeation efficiency of LPNs was better than the drug solution. The RPV-LPNs exhibited a long-lasting in vivo anesthesia effect in both rats and mice.

Conclusion

Considering the low cytotoxicity, the LPNs prepared here could be used as an efficient local anesthetic for the control of pain.

A multifunctional-targeted nanoagent for dual-mode image-guided therapeutic effects on ovarian cancer cells

Purpose

Nanomedicine has emerged as a novel therapeutic modality for cancer treatment and diagnosis. Lipid–polymer hybrid nanoparticles (LPHNPs) are core–shell nanoparticle (NP) structures comprising polymer cores and lipid shells, which exhibit complementary characteristics of both polymeric NPs and liposomes. However, it is difficult to wrap perfluoropentane (PFP) into core–shell NPs in the existing preparation process, which limits its application in the integration of diagnosis and treatment.

Methods

The folate-targeted LPHNPs-loaded indocyanine green/PFP-carrying oxygen (TOI_HNPs) using a combination of two-step method and solution evaporation technique for the first time. The essential properties and dual-mode imaging characteristics of developed NPs were determined. The cellular uptake of TOI_HNPs was detected by confocal microscopy and flow cytometry. The SKOV3 cell viability and apoptosis rate were evaluated by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT) assay and flow cytometry. The ROS was demonstrated by fluorescence microplate reader and the expression of hypoxia-inducible factor 1-alpha (HIF-1α) and IL-6 was detected by Western blot.

Results

TOI_HNPs showed spherical morphology with particle size about (166.83±5.54) nm and zeta potential at −(30.57±1.36) mV. It exhibited better stability than lipid NPs and higher encapsulation efficiency as well as active targeting ability than poly (lactic-co-glycolic acid) (PLGA) NPs. In addition, the novel NPs could also act as the contrast agents for ultrasound and photoacoustic imaging, providing precision guidance and monitoring. Furthermore, TOI_HNPs-mediated photo–sonodynamic therapy (PSDT) caused more serious cell damage and more obvious cell apoptosis, compared with other groups. The PSDT mediated by TOI_HNPs induced generation of intracellular ROS and downregulated the expression of HIF-1α and IL-6 in SKOV3 cells.

Conclusion

This kind of multifunctional-targeted nanoagent may provide an ideal strategy for combination of high therapeutic efficacy and dual-mode imaging guidance.

Enhanced treatment effect of nanoparticles containing cisplatin and a GSH-reactive probe compound

Cisplatin is a highly effective antitumor drug, which can kill cancer cells by crossing-linking DNA and inhibiting transcription, but this process is limited by the combination of cisplatin and many endogenous nucleophiles, such as glutathione (GSH). Thus, when cisplatin enter cells, it is potentially vulnerable to cytoplasmic inactivation by GSH. To settle this bottleneck, we designed and synthesized a probe compound (Probe 1) and fabricated pH-responsed cisplatin, Probe 1-loaded lipid-polymer hybrid NanoParticles (CPNPs) using a single-step sonication method. Probe 1 can specifically bind to GSH, thus avoiding the combination of GSH and cisplatin, and enhancing the pharmacological activity of cisplatin. In vitro studies have suggested CPNPs, compared with cisplatin, loaded lipid-polymer hybrid NanoParticles CNPs (Not contain Probe 1), could efficiently kill MCF-7 human breast cancer cells and A549 human nonsmall lung cancer cell. Hence, the CPNPs provided a new idea for treating cancer.

Ovarian carcinoma biological nanotherapy: Comparison of the advantages and drawbacks of lipid, polymeric, and hybrid nanoparticles for cisplatin delivery

Ovarian carcinoma is one of the most common cancers among women. The most common type of ovarian cancer is epithelial ovarian cancer and cisplatin (DDP) is one of the most interesting chemotherapeutic drugs in clinical regimens for ovarian cancer. Nanoparticles (NPs) including lipid NPs, polymeric NPs, liposomes, dendrimers, oligomers, and nanotubes were usually used for anti-cancer drug delivery. In this study, DDP loaded nanostructured lipid carriers (DDP-NLC), polymeric NPs (DDP-PNP), and lipid-polymer hybrid nanoparticles (DDP-LPN) were prepared for the evaluation in vitro and in vivo. The efficiency of these three kinds of the NPs was compared in terms of in vitro drug release, cellular uptake, in vitro cell growth inhibition, in vivo pharmacokinetics, biodistribution and in vivo antitumor in mice. The size of DDP-PNP (119.8 nm) was smaller than DDP-NLC (132.4 nm) and DDP-LPN (141.2 nm). The release of DDP from DDP-NLC was faster than DDP-PNP. Cellular uptake efficiency of DDP-NLC and DDP-LPN was significantly higher than DDP-PNP. In vivo pharmacokinetics evaluation showed that plasma concentration - time curves (AUCs) of DDP-NLC, DDP-PNP, DDP-LPN and free DDP are 128, 210, 247, and 16 mg/L h, with T_1/2 of 4.4, 5.1, 5.5, and 1.7 mg/L h. DDP-LPN exhibits the highest AUC and the longest T_1/2. In vivo antitumor efficacy results investigated on ovarian cancer bearing BALB/c mice model demonstrated that DDP-LPN showed the strongest antitumor effect. In vitro and in vivo studies demonstrated that DDP-NLC, DDP-PNP and DDP-LPN have different advantages due to the various evaluations. The in vivo anti-tumor results indicate that DDP-LPN may have the best tumor inhibition ability. DDP-NLC, DDP-PNP, and DDP-LPN developed in this study could be used as promising strategies for the treatment of ovarian cancer according to different demands.

Kinetics of mRNA delivery and protein translation in dendritic cells using lipid-coated PLGA nanoparticles

BACKGROUND

Messenger RNA (mRNA) has gained remarkable attention as an alternative to DNA-based therapies in biomedical research. A variety of biodegradable nanoparticles (NPs) has been developed including lipid-based and polymer-based systems for mRNA delivery. However, both systems still lack in achieving an efficient transfection rate and a detailed understanding of the mRNA transgene expression kinetics. Therefore, quantitative analysis of the time-dependent translation behavior would provide a better understanding of mRNA's transient nature and further aid the enhancement of appropriate carriers with the perspective to generate future precision nanomedicines with quick response to treat various diseases.

RESULTS

A lipid-polymer hybrid system complexed with mRNA was evaluated regarding its efficiency to transfect dendritic cells (DCs) by simultaneous live cell video imaging of both particle uptake and reporter gene expression. We prepared and optimized NPs consisting of poly (lactid-co-glycolid) (PLGA) coated with the cationic lipid 1, 2-di-O-octadecenyl-3-trimethylammonium propane abbreviated as LPNs. An earlier developed polymer-based delivery system (chitosan-PLGA NPs) served for comparison. Both NPs types were complexed with mRNA-mCherry at various ratios. While cellular uptake and toxicity of either NPs was comparable, LPNs showed a significantly higher transfection efficiency of ~ 80% while chitosan-PLGA NPs revealed only ~ 5%. Further kinetic analysis elicited a start of protein translation after 1 h, with a maximum after 4 h and drop of transgene expression after 48 h post-transfection, in agreement with the transient nature of mRNA.

CONCLUSIONS

Charge-mediated complexation of mRNA to NPs enables efficient and fast cellular delivery and subsequent protein translation. While cellular uptake of both NP types was comparable, mRNA transgene expression was superior to polymer-based NPs when delivered by lipid-polymer NPs.

Lipid-polymer hybrid nanocarrier-mediated cancer therapeutics: current status and future directions

The new generation of nanoparticles (NPs) encompass attributes of lipids and polymers and are referred to as 'lipid-polymer hybrid nanoparticles' (LPHNPs). LPHNPs have helped shed light on the mechanisms involved in targeted and non-specific drug delivery. Research has also highlighted the opportunities and challenges faced by the use of nanomedicine as personalized therapies in oncology. Here, we review the development of LPHNPs as cancer therapeutics, focusing on the methods deployed for enhancing the targeting efficiency and applications of LPHNPs.

Soft- and hard-lipid nanoparticles: a novel approach to lymphatic drug delivery

With the current advance in nanotechnology, the development has accelerated of a number of nanoparticle-type drugs such as nano-emulsions, lipid emulsions, liposomes, and cell therapeutics. With these developments, attempts are being made to apply these new drugs to healing many intractable diseases related to antibody production, autoimmune disorders, cancer, and organ transplantation in both clinical and nonclinical trials. Drug delivery to the lymphatic system is indispensable for treating these diseases, but the core technologies related to the in vivo distribution characteristics and lymphatic delivery evaluation of these particle-type drugs have not yet been established. Additionally, the core technologies for setting up the pharmacotherapeutic aspects such as their usage and dosages in the development of new drugs do not meet the needs of the market. Therefore, it is necessary to consider dividing these particle-type drugs into soft-lipid nanoparticles that can change size in the process of body distribution and hard-lipid nanoparticles whose surfaces are hardened and whose sizes do not easily change in vivo; these soft- and hard-lipid nanoparticles likely possess different biodistribution characteristics including delivery to the lymphatic system. In this review, we summarize the different types, advantages, limitations, possible remedies, and body distribution characteristics of soft- and hard-lipid nanoparticles based on their administration routes. We also emphasize that it will be necessary to fully understand the differences in distribution between these soft- and hard-lipid nanoparticle-type drugs and to establish pharmacokinetic models for their more ideal lymphatic delivery.

Bridging Systemic Immunity with Gastrointestinal Immune Responses via Oil-in-Polymer Capsules

As peripheral lymphocytes are typically excluded from the gastrointestinal lymph tissues, current parenteral vaccinations fail to simultaneously induce systemic and mucosal responses. To break the natural barrier, "immunoticket" capsules are developed and heralded, which are designed with positive charged shells and oily core to spatiotemporally deliver antigens and all-trans retinoic acid (RA). After intramuscular vaccinations, these capsules function as an immunoticket to cultivate peripheral dendritic cells (DCs) with gut-homing receptors (CCR9). By hitchhiking on the concentration gradient of the CC-motif chemokine ligand 25 (CCL25), the primed DCs would home to the gut associated lymphoid tissues (GALTs) and induce antigen-specific IgA secretion and T cell engagements. Compared with the currently employed RA-involving formulations, the immunoticket capsules stimulate enhanced RA-mediated gut-tropism by mounting the inflammatory innate immunity. Through controlling the RA payload, the potential regulatory T cell engagement is circumvented. In ovalbumin (OVA) and EV71 vaccinations, the immunoticket capsules induce potent serum IgG titer and antigen-specific cytotoxic T cells in the peripheral lymph tissues, as well as robust IgA secretion and T cell engagements on gastrointestinal sites. The data suggest the potential of the immunotickets to serve as a facile, effective, and safe strategy to provide comprehensive immune responses against gastrointestinal infections and diseases.

Development and characterization of gemcitabine hydrochloride loaded lipid polymer hybrid nanoparticles (LPHNs) using central composite design

Lipid polymer hybrid nanoparticles (LPHNs) combine the characteristics and beneficial properties of both polymeric nanoparticles and liposomes. The objective of this study was to design and optimize gemcitabine hydrochloride loaded LPHNs based on the central composite design approach. PLGA 50:50/PLGA 65:35 mass ratio (w/w), soya phosphatidylcholine (SPC)/polymer mass ratio (%, w/w) and amount of DSPE-PEG were chosen as the investigated independent variables. The LPHNs were prepared with modified double emulsion solvent evaporation method and characterized by testing their particle size, encapsulation efficiency, and cumulative release. The composition of optimal formulation was determined as 1,5 (w/w) PLGA 50:50/PLGA 65:35 mass ratio, 30% (w/w) SPC/polymer mass ratio and 15 mg DSPE-PEG. The results showed that the optimal formulation gemcitabine hydrochloride loaded LPHNs had encapsulation efficiency of 45,2%, particle size of 237 nm and cumulative release of 62,3% at the end of 24 h. The morphology of LPHNs was found to be spherical by transmission electron microscopy (TEM) observation. Stability studies showed that LPHNs were physically stable until 12 months at 4 °C and 9 months at 25 °C/60% RH. The results suggest that the LPHNs can be an effective drug delivery system for hydrophilic active pharmaceutical ingredient.

Core-shell nanoparticles for targeted and combination antiretroviral activity in gut-homing T cells

A major sanctuary site for HIV infection is the gut-associated lymphoid tissue (GALT). The α4β7 integrin gut homing receptor is a promising therapeutic target for the virus reservoir because it leads to migration of infected cells to the GALT and facilitates HIV infection. Here, we developed a core-shell nanoparticle incorporating the α4β7 monoclonal antibody (mAb) as a dual-functional ligand for selectively targeting a protease inhibitor (PI) to gut-homing T cells in the GALT while simultaneously blocking HIV infection. Our nanoparticles significantly reduced cytotoxicity of the PI and enhanced its in vitro antiviral activity in combination with α4β7 mAb. We demonstrate targeting function of our nanocarriers in a human T cell line and primary cells isolated from macaque ileum, and observed higher in vivo biodistribution to the murine small intestines where they accumulate in α4β7+ cells. Our LCNP shows the potential to co-deliver ARVs and mAbs for eradicating HIV reservoirs.

Computational Investigations of the Interaction between the Cell Membrane and Nanoparticles Coated with a Pulmonary Surfactant

When inhaled nanoparticles (NPs) come into the deep lung, they develop a biomolecular corona by interacting with the pulmonary surfactant. The adsorption of the phospholipids and proteins gives a new biological identity to the NPs, which may alter their subsequent interactions with cells and other biological entities. Investigations of the interaction between the cell membrane and NPs coated with such a biomolecular corona are important in understanding the role of the biofluids on cellular uptake and estimating the dosing capacity and the nanotoxicology of NPs. In this paper, using dissipative particle dynamics, we investigate how the physicochemical properties of the coating pulmonary surfactant lipids and proteins affect the membrane response for inhaled NPs. We pinpoint several key factors in the endocytosis of lipid NPs, including the deformation of the coating lipids, coating lipid density, and ligand-receptor binding strength. Further studies reveal that the deformation of the coating lipids consumes energy but on the other hand promotes the coating ligands to bind with receptors more tightly. The coating lipid density controls the amount of the ligands as well as the hydrophobicity of the lipid NPs, thus affecting the endocytosis kinetics through the specific and nonspecific interactions. It is also found that the hydrophobic surfactant proteins associated with lipids can accelerate the endocytosis process of the NPs, but the endocytosis efficiency mainly depends on the density of the coating surfactant lipids. These findings can help understand how the pulmonary surfactant alters the biocompatibility of the inhaled NPs and provide some guidelines in designing an NP complex for efficient pulmonary drug delivery.

Lipid-Polymer Hybrid Nanoparticles for Oral Delivery of Tartary Buckwheat Flavonoids

Flavonoids rich in Tartary buckwheat (TBFs) are the acknowledged health-promoting substances, even with the low oral bioavailability due to its chemical instability in gastrointestinal tract and poor intestinal absorption. To obtain the enhanced oral delivery, TBFs, obtained by an environmentally friendly extraction strategy in advance with the amount of 7.66 ± 0.47 mg rutin/g, was incorporated in biocompatible lipid-polymer hybrid nanoparticles (LPNs). Its high encapsulation efficiency of 96.4% ± 1.1%, narrow size distribution of 61.25 ± 1.83 nm with spherical shape, and good storage stability were observed. Compared to free TBFs, TBFs/LPNs exhibited higher antioxidant activity and significant suppression on the pro-inflammatory cytokine secretion in RAW 264.7 macrophage. Moreover, the enhanced delivery of TBFs/LPNs was also embodied in the improved transmembrane transport in Caco-2 monolayer, suggesting its better intestinal absorption, and significantly immune-enhancing efficacy in immunosuppressed mice. These results demonstrated the new perspectives of Tartary buckwheat flavonoids-loaded nanosystem for pharmaceutical and nutraceutical applications.

Hybrid nanoparticle-based nicotine nanovaccines: Boosting the immunological efficacy by conjugation of potent carrier proteins

A series of hybrid nanoparticle-based nicotine nanovaccines (NanoNicVac) were engineered in this work by conjugating potent carrier protein candidates (Keyhole limpet hemocyanin (KLH) multimer, KLH subunit, cross-reactive material 197 (CRM₁₉₇), or tetanus toxoid (TT)) for enhanced immunological efficacy. NanoNicVac with CRM₁₉₇ or TT were processed by dendritic cells more efficiently than that with KLH multimer or subunit. NanoNicVac carrying CRM₁₉₇ or TT exhibited a significantly higher immunogenicity against nicotine and a considerably lower immunogenicity against carrier proteins than NanoNicVac carrying KLH multimer or subunit in mice. The in vivo results revealed that NanoNicVac with CRM₁₉₇ or TT resulted in lower levels of nicotine in the brain of mice after nicotine challenge. All findings suggest that an enhanced immunological efficacy of NanoNicVac can be achieved by using CRM₁₉₇ or TT instead of KLH or KLH subunit as carrier proteins, making NanoNicVac a promising next-generation immunotherapeutic candidate against nicotine addiction.

Lipid Shell-Enveloped Polymeric Nanoparticles with High Integrity of Lipid Shells Improve Mucus Penetration and Interaction with Cystic Fibrosis-Related Bacterial Biofilms

Nanoparticle (NP) mediated drug delivery into viscous biomatrices, e.g., mucus and bacterial biofilms, is challenging. Lipid shell-enveloped polymeric NPs (Lipid@NPs), composed of a polymeric NP core coated with a lipid shell, represent a promising alternative to the current delivery systems. Here, we describe the facile methods to prepare Lipid@NPs with high integrity of lipid shells and demonstrate the potential of Lipid@NPs in an effective mucus penetration and interaction with cystic fibrosis-related bacterial biofilms. Lipid shell-enveloped polystyrene NPs with high integrity of lipid shells ( cLipid@PSNPs) were prepared by using an electrostatically mediated layer-by-layer approach, where the model polystyrene NPs (PSNPs) were first modified with positively charged poly-l-lysine (PLL) and 1,2-dioleoyl-3-trimethylammonium-propane (DOTAP), followed by subsequent fusion with zwitterionic, PEGylated small unilamellar vesicles (SUVs). The interaction of the PSNPs with SUVs was significantly enhanced by modifying the PSNPs with PLL and DOTAP, which eventually resulted in the formation of cLipid@PSNPs, i.e., Lipid@PLL-PSNPs and Lipid@DOTAP-PSNPs. Improved mucus-penetrating property of cLipid@PSNPs was demonstrated by quartz crystal microbalance with dissipation monitoring measurements. Furthermore, fluorescence resonance energy transfer measurements showed that the interaction of the cLipid@PSNPs with bacterial biofilms was significantly promoted. In conclusion, we prepared cLipid@PSNPs via an electrostatically mediated layer-by-layer approach. Our results suggest that the integrity of the lipid envelopes is crucial for enabling the diffusion of Lipid@PSNPs into the mucus layer and promoting the interaction of Lipid@PSNPs with a bacterial biofilm.

Validation of Smart Nanoparticles as Controlled Drug Delivery Systems: Loading and pH-Dependent Release of Pilocarpine

Micelles are good devices for use as controlled drug delivery systems because they exhibit the ability to protect the encapsulated substance from the routes of degradation until they reach the site of action. The present work assesses loading kinetics of a hydrophobic drug, pilocarpine, in polymeric micellar nanoparticles (NPs) and its pH-dependent release in hydrophilic environments. The trigger pH stimulus, pH 5.5, was the value encountered in damaged tissues in solid tumors. The new nanoparticles were prepared from an amphiphilic block copolymer, [(HEMA_19%-DMA_31%)-(FMA_5%-DEA_45%)]. For the present research, three systems were validated, two of them with cross-linked cores and the other without chemical stabilization. A comparison of their loading kinetics and release profiles is discussed, with the support of additional data obtained by scanning electron microscopy and dynamic light scattering. The drug was loaded into the NPs within the first minutes; the load was dependent on the degree of cross-linking. All of the systems experienced a boost in drug release at acidic pH, ranging from 50 to 80% within the first 48 h. NPs with the highest degree (20%) of core cross-linking delivered the highest percentage of drug at fixed times. The studied systems exhibited fine-tuned sustained release features, which may provide a continuous delivery of the drug at specific acidic locations, thereby diminishing side effects and increasing therapeutic rates. Hence, the studied NPs proved to behave as smart controlled drug delivery systems capable of responding to changes in pH.

Smart Nanoparticles Undergo Phase Transition for Enhanced Cellular Uptake and Subsequent Intracellular Drug Release in a Tumor Microenvironment

Inefficient cellular uptake and intracellular drug release at the tumor site are two major obstacles limiting the antitumor efficacy of nanoparticle delivery systems. To overcome both problems, we designed a smart nanoparticle that undergoes phase transition in a tumor microenvironment (TME). The smart nanoparticle is generated using a lipid-polypetide hybrid nanoparticle, which comprises a PEGylated lipid monolayer shell and a pH-sensitive hydrophobic poly-l-histidine core and is loaded with the antitumor drug doxorubicin (DOX). The smart nanoparticle undergoes a two-step phase transition at two different pH values in the TME: (i) At the TME (pH_e: 7.0-6.5), the smart nanoparticle swells, and its surface potential turns from negative to neutral, facilitating the cellular uptake; (ii) After internalization, at the acid endolysosome (pH_endo: 6.5-4.5), the smart nanoparticle dissociates and induces endolysosome escape to release DOX into the cytoplasm. In addition, a tumor-penetrating peptide iNRG was modified on the surface of the smart nanoparticle as a tumor target moiety. The in vitro studies demonstrated that the iNGR-modified smart nanoparticles promoted cellular uptake in the acidic environment (pH 6.8). The in vivo studies showed that the iNGR-modified smart nanoparticles exerted more potent antitumor efficacy against late-stage aggressive breast carcinoma than free DOX. These data suggest that the smart nanoparticles may serve as a promising delivery system for sequential uptake and intracellular drug release of antitumor agents. The easy preparation of these smart nanoparticles may also have advantages in the future manufacture for clinical trials and clinical use.

Nanoparticle-Based Therapeutics for Brain Injury

Brain injuries affect a large patient population with major physical and emotional suffering for patients and their relatives; at a significant cost to the society. Effective diagnostic and therapeutic options available for brain injuries are limited by the complex brain injury pathology involving blood-brain barrier (BBB). Brain injuries, including ischemic stroke and brain trauma, initiate BBB opening for a short period of time, which is followed by a second reopening for an extended time. The leaky BBB and/or the alterations in the receptor expression on BBB may provide opportunities for therapeutic delivery via nanoparticles (NPs). The approaches for therapeutic interventions via NP delivery are aimed at salvaging the pericontusional/penumbra area for possible neuroprotection and neurovascular unit preservation. The focus of this progress report is to provide a survey of NP strategies employed in cerebral ischemia and brain trauma and finally provide insights for improved NP-based diagnostic/treatment approaches.

Charge-reversal-functionalized PLGA nanobubbles as theranostic agents for ultrasonic-imaging-guided combination therapy

The application of the PLGA-based charge-reversal nanobubbles (denoted as Dox-NBs/PPP/P-gp shRNA) in co-delivery of Dox and P-gp shRNA for reversal of drug resistance and ultrasonic imaging-guided combination therapy of chemotherapy and P-gp knockdown in breast cancer.

Lecithin and PLGA-based self-assembled nanocomposite, Lecithmer: preparation, characterization, and pharmacokinetic/pharmacodynamic evaluation

The present study investigates the drug delivery potential of polymer lipid hybrid nanocomposites (Lecithmer®) composed of poly(D,L-lactide-co-glycolide (PLGA) and soya lecithin. Core-shell structure of Lecithmer was evident from cryo-TEM images. Daunorubicin (DNR) and lornoxicam (LNX)-incorporated Lecithmer nanocomposites were evaluated for anticancer and anti-inflammatory activity. DNR- and LNX-loaded Lecithmer had mean particle size of ∼335 and ∼282.7 nm, respectively. Lecithmer formulated with different cationic lipids resulted in lower particle size (∼120 nm) and positive zeta potential. Entrapment efficiency of DNR and LNX was 93.16 and 88.59 %, respectively. In vitro release of DNR from Lecithmer was slower compared to PLGA nanoparticles. DNR release from Lecithmer was significantly higher at pH 5.5 (80.96 %) as compared to pH 7.4 (55.95 %), providing advantage for selective tumor therapy. Similarly, sustained release of LNX (30 % in 10 h) was observed at pH 7.4. DNR in Lecithmer showed superior cytotoxicity on human erythroleukemic K562 cells. Pharmacokinetic study in Wistar rats with i.v. administered DNR-loaded Lecithmer showed higher volume of distribution, lower elimination rate constant, and longer half-life (81.68 L, 0.3535 h(-1), 1.96 h) as compared to DNR solution (57.46 L, 0.4237 h(-1), 1.635 h). Pharmacodynamic evaluation of orally administered LNX-loaded Lecithmer showed superior anti-inflammatory activity with maximum inhibition of 81.2 % vis-à-vis 53.57 % in case of LNX suspension. In light of these results, Lecithmer can be envisaged as a promising nanosystem for parenteral as well as oral drug delivery.

Lipid-polymer hybrid nanocarriers for delivering cancer therapeutics

Cancer remained a major cause of death providing diversified challenges in terms of treatment including non-specific toxicity, chemoresistance and relapse. Nanotechnology- based delivery systems grabbed tremendous attention for delivering cancer therapeutics as they provide benefits including controlled drug release, improved biological half-life, reduced toxicity and targeted delivery. Majority of the nanocarriers consists of either a polymer or a lipid component along with other excipients to stabilize the colloidal system. Lipid-based systems provide advantages like better entrapment efficiency, scalability and low- cost raw materials, however, suffer from limitations including instability, a burst release of the drug, and limited surface functionalization. On the other hand, polymeric systems provide an excellent diversity of chemical modifications, stability, controlled release, however limited drug loading capacities and scale up limit their use. Hybrid nanocarriers consisting of lipid and polymer were able to overcome some of these disadvantages while retaining the advantages of both the systems. Designing a stable lipid-polymer hybrid system requires a thorough understanding of the material properties and their behavior in in vitro and in vivo environments. This review highlights the current status and future prospects of lipid-polymer hybrid systems with a particular focus on cancer nanotherapeutics.

Nanoparticles for drug delivery to the anterior segment of the eye

Commercially available ocular drug delivery systems are effective but less efficacious to manage diseases/disorders of the anterior segment of the eye. Recent advances in nanotechnology and molecular biology offer a great opportunity for efficacious ocular drug delivery for the treatments of anterior segment diseases/disorders. Nanoparticles have been designed for preparing eye drops or injectable solutions to surmount ocular obstacles faced after administration. Better drug pharmacokinetics, pharmacodynamics, non-specific toxicity, immunogenicity, and biorecognition can be achieved to improve drug efficacy when drugs are loaded in the nanoparticles. Despite the fact that a number of review articles have been published at various points in the past regarding nanoparticles for drug delivery, there is not a review yet focusing on the development of nanoparticles for ocular drug delivery to the anterior segment of the eye. This review fills in the gap and summarizes the development of nanoparticles as drug carriers for improving the penetration and bioavailability of drugs to the anterior segment of the eye.

Natural material-decorated mesoporous silica nanoparticle container for multifunctional membrane-controlled targeted drug delivery

To avoid the side effects caused by nonspecific targeting, premature release, weak selectivity, and poor therapeutic efficacy of current nanoparticle-based systems used for drug delivery, we fabricated natural material-decorated nanoparticles as a multifunctional, membrane-controlled targeted drug delivery system. The nanocomposite material coated with a membrane was biocompatible and integrated both specific tumor targeting and responsiveness to stimulation, which improved transmission efficacy and controlled drug release. Mesoporous silica nanoparticles (MSNs), which are known for their biocompatibility and high drug-loading capacity, were selected as a model drug container and carrier. The membrane was established by the polyelectrolyte composite method from chitosan (CS) which was sensitive to the acidic tumor microenvironment, folic acid-modified CS which recognizes the folate receptor expressed on the tumor cell surface, and a CD44 receptor-targeted polysaccharide hyaluronic acid. We characterized the structure of the nanocomposite as well as the drug release behavior under the control of the pH-sensitive membrane switch and evaluated the antitumor efficacy of the system in vitro. Our results provide a basis for the design and fabrication of novel membrane-controlled nanoparticles with improved tumor-targeting therapy.

How the Incorporation of Pluronic Block Copolymers Modulates the Response of Lipid Membranes to Mechanical Stress

We employ atomistic molecular dynamics simulations to investigate the effect that the incorporation of the nonionic amphiphilic copolymer known as Pluronic L64 has on the mechanical stability of a DPPC membrane. The simulations reveal that the incorporation of the polymer chains leads to membranes that can sustain increasing mechanical stresses. Analysis of mechanical, structural, and dynamic properties of the membrane shows that the polymer chains interact strongly with the lipids in the vicinity, restraining their mobility and imparting better mechanical stability to the membrane. The hybrid membranes under tension remain thicker, more ordered, and stiffer in comparison to their lipid analogues. Trans-bilayer lipid movements (flip-flop) are observed and appear to be triggered by the presence of the polymer chains. A careful analysis of the pore formation under high tensions reveals two distinctive mechanisms that depend on the distribution of the hydrophilic polymer blocks in the bilayer. Finally, the rate of growth of the formed membrane defects is slowed down in the presence of polymers. These findings show that Pluronic block copolymers could be exploited for the formation of optimized hybrid nanodevices with controlled elastic and dynamic properties.

Bone-targeting nanoparticle to co-deliver decitabine and arsenic trioxide for effective therapy of myelodysplastic syndrome with low systemic toxicity

Myelodysplastic syndromes (MDS) are a diverse group of bone marrow disorders and clonal hematopoietic stem cell disorders characterized by abnormal blood cells, or reduced peripheral blood cell count. Recent clinical studies on combination therapy of decitabine (DAC) and arsenic trioxide (ATO) have demonstrated synergy on MDS treatment, but the treatment can cause significant side effects to patients. In addition, both drugs have to be administered on a daily basis due to their short half-lives. In addressing key issues of reducing toxic side effects and improving pharmacokinetic profiles of the therapeutic agents, we have developed a new formulation by co-packaging DAC and ATO into alendronate-conjugated bone-targeting nanoparticles (BTNPs). Our pharmacokinetic studies revealed that intravenously administered BTNPs increased circulation time up to 3days. Biodistribution analysis showed that the BTNP facilitated DAC and ATO accumulation in the bone, which is 6.7 and 7.9 times more than untargeted NP. Finally, MDS mouse model treated with BTNPs showed better restoration of complete blood count to normal level, and significantly longer median survival as compared to free drugs or untargeted NPs treatment. Our results support bone-targeted co-delivery of DAC and ATO for effective treatment of MDS.

Polyester-Solid Lipid Mixed Nanoparticles with Improved Stability in Gastro-Intestinal Tract Facilitated Oral Delivery of Larotaxel

The objective of this study was to investigate the role of core stability of nanoparticles on their performances in oral drug delivery. Solid lipids (Geleol Mono and Diglycerides Nf) were incorporated into nanoparticles composed of mPEG-b-PCL by the dialysis method. The prepared solid lipid loaded nanoparticles were found to be spherical nanoparticles with a core state and size distribution dependent on the amount of solid lipid incorporated. The critical aggregation concentrations of lipid-loaded nanoparticles were determined using pyrene fluorescence. Then, the stability of block copolymer in nanoparticles with different solid lipid contents was studied in simulated gastric fluid and simulated intestinal fluid. Solid lipids were found to stabilize nanoparticle cores by improving not only the thermodynamic stability (lowered CAC) of the nanoparticle but also the chemical stability of the block copolymer in the gastrointestinal environment. The stability of the loaded drug (larotaxel, LTX) in nanoparticles with different solid lipid contents was challenged by intestinal homogenate and rat liver microsome, and solid lipid loaded nanoparticles showed superior drug-protecting capability. Solid lipid incorporation exhibited limited influence on the cytotoxicity and cellular uptake but improved the transcytosis of nanoparticles in Caco-2 monolayers. The results of pharmacokinetic study indicated that core stabilization was helpful in promoting oral larotaxel absorption as the absolute bioavailability of LTX delivered by solid lipid loaded nanoparticles was found to be 13.17%, compared with that by the lipid-free nanoparticles (6.264%) and LTX solution (2.435%). Additionally, the results of biodistribution study indicated relatively higher particle integrity of solid lipid loaded nanoparticles, shown by slower liver and spleen accumulation rate, compared with its lipid-free counterpart. Overall, incorporation of solid lipids made the nanoparticles more suitable for oral drug delivery.

Preparation of particulate polymeric therapeutics for medical applications

Particulate therapeutics fabricated from polymeric materials have become increasingly popular over the past several decades. Generally, polymeric systems are easy to synthesize and have tunable parameters, giving them significant potential for wide use in the clinic. They come in many different forms, including as nanoparticles, microparticles, and colloidal gels. In this review, we discuss the current preparation methods for each type of platform, as well as some representative applications. To achieve enhanced performance, lipid coatings and other surface modification techniques for introducing additional functionality are also mentioned. We hope that, by outlining the various methods and techniques for their preparation, it will be possible to provide insights into the utility of these polymeric platforms and further encourage their development for biomedical applications.

Multifunctional folate receptor-targeting and pH-responsive nanocarriers loaded with methotrexate for treatment of rheumatoid arthritis

Rheumatoid arthritis (RA) is an autoimmune disease characterized by progressive cartilage and bone destruction. Activated macrophages that overexpress folic acid (FA) receptors play an important role in RA, due to their abundance in inflamed synovial membrane and joints. In an effort to deliver drugs to the inflamed tissues, multifunctional FA receptor-targeting and pH-responsive nanocarriers were developed. They were composed of lipids, polyethylene glycol (PEG)-poly(lactic-co-glycolic acid) (PLGA) forming a hydrophilic shell, FA around the hydrophilic shell as a targeting ligand, and poly(cyclohexane-1,4-diylacetone dimethylene ketal) (PCADK) and PLGA as a hydrophobic core. PCADK also acts as a pH-responsive material. Methotrexate (Mtx) was encapsulated in the nanoparticles, which exhibited pH-responsive release in vitro. Cellular uptake and cytotoxicity experiments revealed that FA-PEG-PLGA/PCADK-lipid nanoparticles loaded with Mtx (FA-PPLNPs) exhibited superior cellular uptake and higher cytotoxicity to activated macrophages than PPLNPs/Mtx. The therapeutic effect of FA-PPLNPs/Mtx in RA was confirmed in an adjuvant-induced arthritis rat model. These results suggest that the multifunctional folate receptor-targeting and pH-responsive nanocarriers are promising for the treatment of RA.

"One-Pot" Fabrication of Highly Versatile and Biocompatible Poly(vinyl alcohol)-porphyrin-based Nanotheranostics

Nanoparticle-based theranostic agents have emerged as a new paradigm in nanomedicine field for integration of multimodal imaging and therapeutic functions within a single platform. However, the clinical translation of these agents is severely limited by the complexity of fabrication, long-term toxicity of the materials, and unfavorable biodistributions. Here we report an extremely simple and robust approach to develop highly versatile and biocompatible theranostic poly(vinyl alcohol)-porphyrin nanoparticles (PPNs). Through a “one-pot” fabrication process, including the chelation of metal ions and encapsulation of hydrophobic drugs, monodispersenanoparticle could be formed by self-assembly of a very simple and biocompatible building block (poly(vinyl alcohol)-porphyrin conjugate). Using this approach, we could conveniently produce multifunctional PPNs that integrate optical imaging, positron emission tomography (PET), photodynamic therapy (PDT), photothermal therapy (PTT) and drug delivery functions in one formulation. PPNs exhibited unique architecture-dependent fluorescence self-quenching, as well as photodynamic- and photothermal- properties. Near-infrared fluorescence could be amplified upon PPN dissociation, providing feasibility of low-background fluorescence imaging. Doxorubicin (DOX)-loaded PPNs achieved 53 times longer half-life in blood circulation than free DOX. Upon irradiation by near infrared light at a single excitation wavelength, PPNs could be activated to release reactive oxygen species, heat and drugs simultaneously at the tumor sites in mice bearing tumor xenograft, resulting in complete eradication of tumors. Due to their organic compositions, PPNs showed no obvious cytotoxicity in mice via intravenous administration during therapeutic studies. This highly versatile and multifunctional PPN theranostic nanoplatform showed great potential for the integration of multimodal imaging and therapeutic functions towards personalized nanomedicine against cancers.

Rationalization of a nanoparticle-based nicotine nanovaccine as an effective next-generation nicotine vaccine: A focus on hapten localization

A lipid-polymeric hybrid nanoparticle-based next-generation nicotine nanovaccine was rationalized in this study to combat nicotine addiction. A series of nanovaccines, which had nicotine-haptens localized on carrier protein (LPKN), nanoparticle surface (LPNK), or both (LPNKN), were designed to study the impact of hapten localization on their immunological efficacy. All three nanovaccines were efficiently taken up and processed by dendritic cells. LPNKN induced a significantly higher immunogenicity against nicotine and a significantly lower anti-carrier protein antibody level compared to LPKN and LPNK. Meanwhile, it was found that the anti-nicotine antibodies elicited by LPKN and LPNKN bind nicotine stronger than those elicited by LPKN, and LPNK and LPNKN resulted in a more balanced Th1-Th2 immunity than LPKN. Moreover, LPNKN exhibited the best ability to block nicotine from entering the brain of mice. Collectively, the results demonstrated that the immunological efficacy of the hybrid nanoparticle-based nicotine vaccine could be enhanced by modulating hapten localization, providing a promising strategy to combatting nicotine addiction.