Improved cellular uptake of chitosan-modified PLGA nanospheres by A549 cells

Poly(lactic-co-glycolic) acid nanoparticles localize in vesicles after diffusing into cells and are retained by intracellular traffic modulators

Aim: We investigated our previous finding of increased retention of poly(lactic-co-glycolic) acid nanoparticles (PLGA-NPs) with metabolic inhibitors (MI) and studied the effect of some small molecule inhibitors on PLGA-NP assimilation. Materials & methods: Intracellular PLGA-NP colocalization in the presence of MI was investigated by confocal microscopy. Intracellular retention of PLGA-NPs by some small molecules was estimated by fluorescence microscopy and flow cytometry after Pulse/Chase experiments. Results: MI caused PLGA-NP colocalization in intracellular membranous structures, mainly endosomes and lysosomes. Some small molecule inhibitors demonstrated increased intracellular PLGA-NP accumulation. Conclusion: This study elucidates the movement of PLGA-NP in cells and suggests that clinically used small molecules can reduce their extrusion by enhancing their stay within intracellular vesicles, with possible clinically beneficial consequences.

Review on PLGA Polymer Based Nanoparticles with Antimicrobial Properties and Their Application in Various Medical Conditions or Infections

The rise in the resistance to antibiotics is due to their inappropriate use and the use of a broad spectrum of antibiotics. This has also contributed to the development of multidrug-resistant microorganisms, and due to the unavailability of suitable new drugs for treatments, it is difficult to control. Hence, there is a need for the development of new novel, target-specific antimicrobials. Nanotechnology, involving the synthesis of nanoparticles, may be one of the best options, as it can be manipulated by using physicochemical properties to develop intelligent NPs with desired properties. NPs, because of their unique properties, can deliver drugs to specific targets and release them in a sustained fashion. The chance of developing resistance is very low. Polymeric nanoparticles are solid colloids synthesized using either natural or synthetic polymers. These polymers are used as carriers of drugs to deliver them to the targets. NPs, synthesized using poly-lactic acid (PLA) or the copolymer of lactic and glycolic acid (PLGA), are used in the delivery of controlled drug release, as they are biodegradable, biocompatible and have been approved by the USFDA. In this article, we will be reviewing the synthesis of PLGA-based nanoparticles encapsulated or loaded with antibiotics, natural products, or metal ions and their antibacterial potential in various medical applications.

The In Vitro, In Vivo, and PBPK Evaluation of a Novel Lung-Targeted Cardiac-Safe Hydroxychloroquine Inhalation Aerogel

Hydroxychloroquine (HCQ) was repurposed for COVID-19 treatment. Subtherapeutic HCQ lung levels and cardiac toxicity of oral HCQ were overcome by intratracheal (IT) administration of lower HCQ doses. The crosslinker-free supercritical fluid technology (SFT) produces aerogels and impregnates them with drugs in their amorphous form with efficient controlled release. Mechanistic physiologically based pharmacokinetic (PBPK) modeling can predict the lung's epithelial lining fluid (ELF) drug levels. This study aimed to develop a novel HCQ SFT formulation for IT administration to achieve maximal ELF levels and minimal cardiac toxicity. HCQ SFT formulation was prepared and evaluated for physicochemical, in vitro release, pharmacokinetics, and cardiac toxicity. Finally, the rat HCQ ELF concentrations were predicted using PBPK modeling. HCQ was amorphous after loading into the chitosan-alginate nanoporous microparticles (22.7±7.6 μm). The formulation showed a zero-order release, with only 40% released over 30 min compared to 94% for raw HCQ. The formulation had a tapped density of 0.28 g/cm3 and a loading efficiency of 35.3±1.3%. The IT administration of SFT HCQ at 1 mg/kg resulted in 23.7-fold higher bioavailability, fourfold longer MRT, and eightfold faster absorption but lower CK-MB and LDH levels than oral raw HCQ at 4 mg/kg. The PBPK model predicted 6 h of therapeutic ELF levels for IT SFT HCQ and a 100-fold higher ELF-to-heart concentration ratio than oral HCQ. Our findings support the feasibility of lung-targeted and more effective SFT HCQ IT administration for COVID-19 compared to oral HCQ with less cardiac toxicity. Graphical abstract.

Synthesis and Evaluation of BSA-Loaded PLGA-Chitosan Composite Nanoparticles for the Protein-Based Drug Delivery System

The purpose of this study was to synthesize composite nanoparticles (NPs) based on poly(d,l-lactic-co-glycolic acid) (PLGA) and chitosan (CS) and evaluate their suitability for the delivery of protein-based therapeutic molecules. Composite NPs possess a unique property which is not exhibited by any other polymer. Unlike other polymers, only the composite NPs lead to improved transfection efficiency and sustained release of protein. The composite NP were prepared by grafting CS on the surface of PLGA NPs through EDC-NHS coupling reaction. The size of bovine serum albumin (BSA)-loaded PLGA NPs and BSA-loaded PLGA-CS composite NPs was 288 ± 3 and 363 ± 4 nm, respectively. The zeta potential of PLGA NPs is -18 ± 0.23, and that of composite particles is 19 ± 0.40, thus confirming the successful addition of CS on the surface of PLGA NPs. Composite NPs were characterized using dynamic light scattering, scanning/transmission electron microscopy, Fourier transform infrared spectroscopy, X-ray diffraction, release profile, and gel electrophoresis. The encapsulation efficiency of PLGA NPs was 88%. These composite NPs were easily uptaken by the A549 cell line with no or minimal cytotoxicity. The present study emphasizes that the composite NPs are suitable for delivery of BSA into the cells with no cytotoxicity or very little cytotoxicity, while maintaining the integrity of the encapsulated BSA.

Recent advances in SN-38 drug delivery system

DNA topoisomerase I plays a key role in lubricatingthe wheels of DNA replication or RNA transcription through breaking and reconnecting DNA single-strand. It is widely known that camptothecin and its derivatives (CPTs) have inhibitory effects on topoisomerases I, and have obtained some clinical benefits in cancer treatment. The potent cytotoxicity makes 7-ethyl-10-hydroxycamptothecin (SN-38) become a brilliant star among these derivatives. However, some undesirable physical and chemical properties of this compound, including poor solubility and stability, seriously hinder its effective delivery to tumor sites. In recent years, strategies to alleviate these defects have aroused extensive research interest. By focusing on the loading mechanism, basic nanodrug delivery systems with SN-38 loaded, like nanoparticles, liposomes and micelles, are demonstrated here. Additionally, functionalized nanodrug delivery systems of SN-38 including prodrug and active targeted nanodrug delivery systems and delivery systems designed to overcome drug resistance are also reviewed. At last, challenges for future research in formulation development and clinical translation of SN-38 drug delivery system are discussed.

A Totipotent "All-In-One" Peptide Sequentially Blocks Immune Checkpoint and Reverses the Immunosuppressive Tumor Microenvironment

Immune checkpoint blockade combined with reversal of the immunosuppressive tumor microenvironment (TME) can dramatically enhance anti-tumor immunity, which can be achieved by using multiple-agent therapy. However, the optimal dose and order of administration of different agents remain elusive. To address this dilemma, multiple agents are often grafted together to construct "all-in-one" totipotent drugs, but this usually comes at the cost of a lack of synergy between the agents. Herein, by comprehensively analyzing the conserved sites of the immune checkpoint and TME drug targets, peptide secondary structures, assembly properties, and other physicochemical properties, a high-content peptide library is designed. By using the "3D-molecular-evolution" screening strategy, an efficient and totipotent "all-in-one" peptide (TAP) is obtained, which possesses the abilities of self-assembling, blocking the PD-1/PD-L1 axis, inhibiting Rbm38-eIF4E complex formation, and activating p53. It is shown that in mice treated with TAP, with either subcutaneous tumors or patient-derived xenografts, PD-L1 is blocked, with increased activation of both T and NK cells whilst reversing the immunosuppressive TME. Moreover, TAP can mitigate tumor activity and suppress tumor growth, showing superior therapeutic effect over antibody-based drugs.

Nanomaterials against intracellular bacterial infection: from drug delivery to intrinsic biofunction

Fighting intracellular bacteria with strong antibiotics evading remains a long-standing challenge. Responding to and regulating the infectious microenvironment is crucial for treating intracellular infections. Sophisticated nanomaterials with unique physicochemical properties exhibit great potential for precise drug delivery towards infection sites, along with modulating infectious microenvironment via their instinct bioactivity. In this review, we first identify the key characters and therapeutic targets of intracellular infection microenvironment. Next, we illustrate how the nanomaterials physicochemical properties, such as size, charge, shape and functionalization affect the interaction between nanomaterials, cells and bacteria. We also introduce the recent progress of nanomaterial-based targeted delivery and controlled release of antibiotics in intracellular infection microenvironment. Notably, we highlight the nanomaterials with unique intrinsic properties, such as metal toxicity and enzyme-like activity for the treatment of intracellular bacteria. Finally, we discuss the opportunities and challenges of bioactive nanomaterials in addressing intracellular infections.

Liver-specific drug delivery platforms: Applications for the treatment of alcohol-associated liver disease

Alcohol-associated liver disease (ALD) is a common chronic liver disease and major contributor to liver disease-related deaths worldwide. Despite its pre-valence, there are few effective pharmacological options for the severe stages of this disease. While much pre-clinical research attention is paid to drug development in ALD, many of these experimental therapeutics have limitations such as poor pharmacokinetics, poor efficacy, or off-target side effects due to systemic administration. One means of addressing these limitations is through liver-targeted drug delivery, which can be accomplished with different platforms including liposomes, polymeric nanoparticles, exosomes, bacteria, and adeno-associated viruses, among others. These platforms allow drugs to target the liver passively or actively, thereby reducing systemic circulation and increasing the ‘effective dose’ in the liver. While many studies, some clinical, have applied targeted delivery systems to other liver diseases such as viral hepatitis or hepatocellular carcinoma, only few have investigated their efficacy in ALD. This review provides basic information on these liver-targeting drug delivery platforms, including their benefits and limitations, and summarizes the current research efforts to apply them to the treatment of ALD in rodent models. We also discuss gaps in knowledge in the field, which when addressed, may help to increase the efficacy of novel therapies and better translate them to humans.

Exploring the intrinsic micro-/nanoparticle size on their in vivo fate after lung delivery

Micro-/nanocarriers due to their significant advantages are widely investigated in pulmonary drug delivery. However, different size carriers have varied drug release rate, concealing the effect of particle size on the fate of drugs in vivo. Therefore, by keeping drug release rate comparable, the objective of this study is to elucidate the influence of particle size itself on drug in vivo fate after intratracheal instillation to mice. Here, using paclitaxel (PTX) as a drug model, 100 nm, 300 nm, 800 nm, and 2500 nm poly(lactide-co-glycolide) (PLGA) particles with the same release rate were prepared. It was demonstrated that the in vivo fate of particles after lung delivery was size-dependent. Consistent with most reports of model particles with neglected release kinetics, the mucus penetration capacity in airtifical mucus decreased with increasing particle size and there is no significant difference between 800 nm and 2500 nm particles. The in vivo airway distribution experiments confirmed the results of the in vitro mucus penetration study, that is, the smaller the particles, the more distributed in the airway. Both in vitro and in vivo macrophage uptake results confirmed that the larger particles were more readily taken up by macrophages. In contrast, the uptake of smaller particles in A549 cells was higher than that of larger particles. Some new findings were disclosed in lung retention, lung absorption and lung targeting. Different from previous reports, this study demonstrated that particles with smaller size had longer lung retention, AUC_(0-t) in bronchoalveolar lavage fluid (BALF) of 100 nm particles was 1.6, 1.9, 2.5 times higher than that of 300 nm, 800 nm, and 2500 nm particles and 11.7 times of the PTX solution group. The same trend was observed in lung tissue absorption, the AUC_(0-t) in the lavaged lung of 100 nm particles was 1.8, 2.2, 2.8, 8.6 times higher than that of 300 nm, 800 nm, 2500 nm particles and PTX solution groups, respectively. The lung targeting efficiency was particles size independent. In conclusion, the in vivo fate of particles with the same release kinetics after intratracheal instillation is size-dependent, smaller size particles are conducive for lung retention and lung absorption. Overall, our study provided scientific guidance for the rational design of particle based pulmonary drug delivery system.

PLGA-Based Composites for Various Biomedical Applications

Polymeric materials have been extensively explored in the field of nanomedicine; within them, poly lactic-co-glycolic acid (PLGA) holds a prominent position in micro- and nanotechnology due to its biocompatibility and controllable biodegradability. In this review we focus on the combination of PLGA with different inorganic nanomaterials in the form of nanocomposites to overcome the polymer’s limitations and extend its field of applications. We discuss their physicochemical properties and a variety of well-established synthesis methods for the preparation of different PLGA-based materials. Recent progress in the design and biomedical applications of PLGA-based materials are thoroughly discussed to provide a framework for future research.

Nanoparticle radiosensitization: from extended local effect modeling to a survival modification framework of compound Poisson additive killing and its carbon dots validation

Objective. To construct an analytical model instead of local effect modeling for the prediction of the biological effectiveness of nanoparticle radiosensitization. Approach. An extended local effects model is first proposed with a more comprehensive description of the nanoparticles mediated local killing enhancements, but meanwhile puts forward challenging issues that remain difficult and need to be further studied. As a novel method instead of local effect modeling, a survival modification framework of compound Poisson additive killing is proposed, as the consequence of an independent additive killing by the assumed equivalent uniform doses of individual nanoparticles per cell under the LQ model. A compound Poisson killing (CPK) model based on the framework is thus derived, giving a general expression of nanoparticle mediated LQ parameter modification. For practical use, a simplified form of the model is also derived, as a concentration dependent correction only to the α parameter, with the relative correction (α″/α) dominated by the mean number, and affected by the agglomeration of nanoparticles per cell. For different agglomeration state, a monodispersion model of the dispersity factor η = 1, and an agglomeration model of 2/3 < η < 1, are provided for practical prediction of (α″/α) value respectively. Main results. Initial validation by the radiosensitization of HepG2 cells by carbon dots showed a high accuracy of the CPK model. In a safe range of concentration (0.003–0.03 μg μl−1) of the carbon dots, the prediction errors of the monodispersion and agglomeration models were both within 2%, relative to the clonogenic survival data of the sensitized HepG2 cells. Significance. The compound Poisson killing model provides a novel approach for analytical prediction of the biological effectiveness of nanoparticle radiosensitization, instead of local effect modeling.

Chitosan/poly(lactic-co-glycolic)acid Nanoparticle Formulations with Finely-Tuned Size Distributions for Enhanced Mucoadhesion

Non-parenteral drug delivery systems using biomaterials have advantages over traditional parenteral strategies. For ocular and intranasal delivery, nanoparticulate systems must bind to and permeate through mucosal epithelium and other biological barriers. The incorporation of mucoadhesive and permeation-enhancing biomaterials such as chitosan facilitate this, but tend to increase the size and polydispersity of the nanoparticles, making practical optimization and implementation of mucoadhesive nanoparticle formulations a challenge. In this study, we adjusted key poly(lactic-co-glycolic) acid (PLGA) nanoparticle formulation parameters including the organic solvent and co-solvent, the concentration of polymer in the organic phase, the composition of the aqueous phase, the sonication amplitude, and the inclusion of chitosan in the aqueous phase. By doing so, we prepared four statistically unique size groups of PLGA NPs and equally-sized chitosan-PLGA NP counterparts. We loaded simvastatin, a candidate for novel ocular and intranasal delivery systems, into the nanoparticles to investigate the effects of size and surface modification on drug loading and release, and we quantified size- and surface-dependent changes in mucoadhesion in vitro. These methods and findings will contribute to the advancement of mucoadhesive nanoformulations for ocular and nose-to-brain drug delivery.

Infection microenvironment-related antibacterial nanotherapeutic strategies

The emergence and spread of antibiotic resistance is one of the biggest challenges in public health. There is an urgent need to discover novel agents against the occurrence of multidrug-resistant bacteria, such as methicillin-resistant Staphylococcus aureus and vancomycin-resistant enterococci. The drug-resistant pathogens are able to grow and persist in infected sites, including biofilms, phagosomes, or phagolysosomes, which are more difficult to eradicate than planktonic ones and also foster the development of drug resistance. For years, various nano-antibacterial agents have been developed in the forms of antibiotic nanocarriers. Inorganic nanoparticles with intrinsic antibacterial activity and inert nanoparticles assisted by external stimuli, including heat, photon, magnetism, or sound, have also been discovered. Many of these strategies are designed to target the unique microenvironment of bacterial infections, which have shown potent antibacterial effects in vitro and in vivo. This review summarizes ongoing efforts on antibacterial nanotherapeutic strategies related to bacterial infection microenvironments, including targeted antibacterial therapy and responsive antibiotic delivery systems. Several grand challenges and future directions for the development and translation of effective nano-antibacterial agents are also discussed. The development of innovative nano-antibacterial agents could provide powerful weapons against drug-resistant bacteria in systemic or local bacterial infections in the foreseeable future.

Polymer nano-systems for the encapsulation and delivery of active biomacromolecular therapeutic agents

Biomacromolecular therapeutic agents, particularly proteins, antigens, enzymes, and nucleic acids are emerging as powerful candidates for the treatment of various diseases and the development of the recent vaccine based on mRNA highlights the enormous potential of this class of drugs for future medical applications. However, biomacromolecular therapeutic agents present an enormous delivery challenge compared to traditional small molecules due to both a high molecular weight and a sensitive structure. Hence, the translation of their inherent pharmaceutical capacity into functional therapies is often hindered by the limited performance of conventional delivery vehicles. Polymer drug delivery systems are a modular solution able to address those issues. In this review, we discuss recent developments in the design of polymer delivery systems specifically tailored to the delivery challenges of biomacromolecular therapeutic agents. In the future, only in combination with a multifaceted and highly tunable delivery system, biomacromolecular therapeutic agents will realize their promising potential for the treatment of diseases and for the future of human health.

Chitosan Nanoparticles at the Biological Interface: Implications for Drug Delivery

The unique properties of chitosan make it a useful choice for various nanoparticulate drug delivery applications. Although chitosan is biocompatible and enables cellular uptake, its interactions at cellular and systemic levels need to be studied in more depth. This review focuses on the various physical and chemical properties of chitosan that affect its performance in biological systems. We aim to analyze recent research studying interactions of chitosan nanoparticles (NPs) upon their cellular uptake and their journey through the various compartments of the cell. The positive charge of chitosan enables it to efficiently attach to cells, increasing the probability of cellular uptake. Chitosan NPs are taken up by cells via different pathways and escape endosomal degradation due to the proton sponge effect. Furthermore, we have reviewed the interaction of chitosan NPs upon in vivo administration. Chitosan NPs are immediately surrounded by a serum protein corona in systemic circulation upon intravenous administration, and their biodistribution is mainly to the liver and spleen indicating RES uptake. However, the evasion of RES system as well as the targeting ability and bioavailability of chitosan NPs can be improved by utilizing specific routes of administration and covalent modifications of surface properties. Ongoing clinical trials of chitosan formulations for therapeutic applications are paving the way for the introduction of chitosan into the pharmaceutical market and for their toxicological evaluation. Chitosan provides specific biophysical properties for effective and tunable cellular uptake and systemic delivery for a wide range of applications.

Improved oral delivery of insulin by PLGA nanoparticles coated with 5β-cholanic acid conjugated glycol chitosan

Oral insulin has been regarded as the best alternative to insulin injection in therapy of diabetes because of its convenience and painlessness. However, several obstacles in the gastrointestinal tract, such as gastric acid and enzyme, greatly reduce the bioavailability of oral insulin. Herein, we report design and preparation of poly (d, l-lactic-co-glycolic acid) nanoparticles (PLGA NPs) coated with 5β-cholanic acid modified glycol chitosan (GC-CA) (GC-CA@PLGA NPs) to improve the oral delivery of insulin. The GC-CA@PLGA NPs with the size of (302.73 ± 5.13 nm) and zeta potential of (25.03 ± 0.31 mV) were synthesized using the double-emulsion method. The insulin-loading capacity and encapsulation efficiency were determined to be 5.77 ± 0.58% and 51.99 ± 5.27%, respectively. Compared with GC-modified PLGA NPs (GC@PLGA NPs) and bare PLGA NPs, the GC-CA@PLGA NPs showed excellent stability and uptake by Caco-2 cells after simulated gastric acid digestion. Further experiment suggests good biocompatibility of GC-CA@PLGA NPs, including hemolysis and cytotoxicity. Inin vivoexperiment, the insulin loaded in the GC-CA@PLGA NPs exhibited a long-term and stable release profile for lowering blood glucose and presented 30.43% bioavailability in oral administration. In brief, we have developed an efficient and safe drug delivery system, GC-CA@PLGA NPs, for significantly improved oral administration of insulin, which may find potential application in the treatment of diabetes.

Glycolipid-Containing Nanoparticle Vaccine Engages Invariant NKT Cells to Enhance Humoral Protection against Systemic Bacterial Infection but Abrogates T-Independent Vaccine Responses

CD4⁺ T cells enable the critical B cell humoral immune protection afforded by most effective vaccines. We and others have recently identified an alternative source of help for B cells in mice, invariant NK T (iNKT) cells. iNKT cells are innate glycolipid-specific T cells restricted to the nonpolymorphic Ag-presenting molecule CD1d. As such, iNKT cells respond to glycolipids equally well in all people, making them an appealing adjuvant for universal vaccines. We tested the potential for the iNKT glycolipid agonist, α-galactosylceramide (αGC), to serve as an adjuvant for a known human protective epitope by creating a nanoparticle that delivers αGC plus antigenic polysaccharides from Streptococcus pneumoniae αGC-embedded nanoparticles activate murine iNKT cells and B cells in vitro and in vivo, facilitate significant dose sparing, and avoid iNKT anergy. Nanoparticles containing αGC plus S. pneumoniae polysaccharides elicits robust IgM and IgG in vivo and protect mice against lethal systemic S. pneumoniae However, codelivery of αGC via nanoparticles actually eliminated Ab protection elicited by a T-independent S. pneumoniae vaccine. This is consistent with previous studies demonstrating iNKT cell help for B cells following acute activation, but negative regulation of B cells during chronic inflammation. αGC-containing nanoparticles represent a viable platform for broadly efficacious vaccines against deadly human pathogens, but their potential for eliminating B cells under certain conditions suggests further clarity on iNKT cell interactions with B cells is warranted.

Oral SMEDDS promotes lymphatic transport and mesenteric lymph nodes target of chlorogenic acid for effective T-cell antitumor immunity

BACKGROUND

Mesenteric lymph nodes (MLNs) are critical draining lymph nodes of the immune system that accommodate more than half of the body's lymphocytes, suggesting their potential value as a cancer immunotherapy target. Therefore, efficient delivery of immunomodulators to the MLNs holds great potential for activating immune responses and enhancing the efficacy of antitumor immunotherapy. Self-microemulsifying drug delivery systems (SMEDDS) have attracted increasing attention to improving oral bioavailability by taking advantage of the intestinal lymphatic transport pathway. Relatively little focus has been given to the lymphatic transport advantage of SMEDDS for efficient immunomodulators delivery to the MLNs. In the present study, we aimed to change the intestinal lymphatic transport paradigm from increasing bioavailability to delivering high concentrations of immunomodulators to the MLNs.

METHODS

Chlorogenic acid (CHA)-encapsulated SMEDDS (CHA-SME) were developed for targeted delivery of CHA to the MLNs. The intestinal lymphatic transport, immunoregulatory effects on immune cells, and overall antitumor immune efficacy of CHA-SME were investigated through in vitro and in vivo experiments.

RESULTS

CHA-SME enhanced drug permeation through intestinal epithelial cells and promoted drug accumulation within the MLNs via the lymphatic transport pathway. Furthermore, CHA-SME inhibited tumor growth in subcutaneous and orthotopic glioma models by promoting dendritic cell maturation, priming the naive T cells into effector T cells, and inhibiting the immunosuppressive component. Notably, CHA-SME induced a long-term immune memory effect for immunotherapy.

CONCLUSIONS

These findings indicate that CHA-SME have great potential to enhance the immunotherapeutic efficacy of CHA by activating antitumor immune responses.

Afatinib-loaded inhalable PLGA nanoparticles for localized therapy of non-small cell lung cancer (NSCLC)-development and in-vitro efficacy

Afatinib (AFA) is a potent aniline-quinazoline derivative, approved by the Food and Drug Administration (FDA) in 2013, as a first-line treatment for metastatic non-small cell lung cancer (NSCLC). However, its clinical application is highly limited by its poor solubility, and consequently low bioavailability. We hypothesize that loading of AFA into biodegradable PLGA nanoparticles for localized inhalational drug delivery will be instrumental in improving therapeutic outcomes in NSCLC patients. Formulated AFA nanoparticles (AFA-NP) were evaluated for physicochemical properties (particle size: 180.2 ± 15.6 nm, zeta potential: - 23.1 ± 0.2 mV, % entrapment efficiency: 34.4 ± 2.3%), formulation stability, in-vitro aerosol deposition behavior, and anticancer efficacy. Stability studies revealed the physicochemical stability of AFA-NP. Moreover, AFA-NP exhibited excellent inhalable properties (mass median aerodynamic diameter (MMAD): 4.7 ± 0.1 μm; fine particle fraction (FPF): 77.8 ± 4.3%), indicating efficient particle deposition in deep lung regions. With respect to in-vitro drug release, AFA-NP showed sustained drug release with cumulative release of 56.8 ± 6.4% after 48 h. Cytotoxic studies revealed that encapsulation of AFA into PLGA nanoparticles significantly enhanced its cytotoxic potential in KRAS-mutated NSCLC cell lines (A549, H460). Cellular uptake studies revealed enhanced internalization of coumarin-loaded nanoparticles compared to plain coumarin in A549. In addition, 3D tumor spheroid studies demonstrated superior efficacy of AFA-NP in tumor penetration and growth inhibition. To conclude, we have established in-vitro efficacy of afatinib-loaded PLGA nanoparticles as inhalable NSCLC therapy, which will be of great significance when designing preclinical and clinical studies. Graphical abstract.

Development of a chitosan-modified PLGA nanoparticle vaccine for protection against Escherichia coli K1 caused meningitis in mice

Background

Escherichia coli K1 (E. coli K1) caused neonatal meningitis remains a problem, which rises the urgent need for an effective vaccine. Previously, we rationally designed and produced the recombinant protein OmpAVac (Vo), which elicited protective immunity against E. coli K1 infection. However, Vo has limited stability, which hinders its future industrial application.

Method

Chitosan-modified poly (lactic-co-glycolic acid) (PLGA) nanoparticles were prepared and used as carried for the recombinant Vo. And the safety, stability and immunogenicity of Vo delivered by chitosan-modified PLGA nanoparticles were tested in vitro and in a mouse model of bacteremia.

Results

We successfully generated chitosan-modified PLGA nanoparticles for the delivery of recombinant Vo (VoNP). In addition, we found that a freeze-drying procedure increases the stability of the VoNPs without changing the shape, size distribution and encapsulation of the Vo protein. Unlike aluminum adjuvant, the nanoparticles that delivered Vo were immunoprotective in mice even after storage for as long as 180 days.

Conclusions

We identified an effective strategy to improve the stability of Vo to maintain its immunogenicity, which will contribute to the future development of vaccines against E. coli K1.

Hyaluronic acid engrafted metformin loaded graphene oxide nanoparticle as CD44 targeted anti-cancer therapy for triple negative breast cancer

BACKGROUND

Triple negative breast cancer (TNBC) is the most aggressive form of breast cancer with limited treatment modalities. It is associated with high propensity of cancer recurrence.

METHODS

UV Spectroscopy, FTIR, DLS, Zeta potential, TEM and SEM were employed to characterize nanoparticles. MTT assay, Wound healing assay, SEM, Immunocytochemistry analysis, Western blot, RT-PCR, mammosphere formation assay were employed to study apoptosis, cell migration and stemness. Tumor regression was studied in chick embryo xenograft and BALB/c mice model.

RESULTS

Hylaluronic acid engrafted metformin loaded graphene oxide (HA-GO-Met) nanoparticles exhibited an anti-cancer efficacy at much lower dosage as compared to metformin alone. HA-GO-Met nanoparticles induced apoptosis and inhibited cell migration of TNBC cells by targeting miR-10b/PTEN axis via NFkB-p65. Upregulation of PTEN affected pAKT(473) expression that induced apoptosis. Cell migration was inhibited by reduction of pFAK/integrinβ1 expressions. Treatment inhibited epithelial mesenchymal transition (EMT) and reduced stemness as evident from the increase in E-cadherin expression, inhibition of mammosphere formation and low expression levels of stemness markers including nanog, oct4 and sox2 as compared to control. Moreover, tumor regression was studied in chick embryo xenograft and BALB/c mice model. HA-GO-Met nanoparticle treatment reduced tumor load and nullified toxicity in peripheral organs imparted by tumor.

CONCLUSIONS

HA-GO-Met nanoparticles exhibited an enormous anti-cancer efficacy in TNBC in vitro and in vivo.

GENERAL SIGNIFICANCE

HA-GO-Met nanoparticles induced apoptosis and attenuated cell migration in TNBC. It nullified overall toxicity imparted by tumor load. It inhibited EMT and reduced stemness and thereby addressed the issue of cancer recurrence.

Oral mucus-penetrating PEGylated liposomes to improve drug absorption: Differences in the interaction mechanisms of a mucoadhesive liposome

We investigated the feasibility of densely polyethylene glycol (PEG2000)-modified liposomes as mucus-penetrating particles (MPPs) for oral delivery of systemically absorbed peptides. The oral absorption of MPPs and mucoadhesive liposomes modified with glycol chitosan (GCS) was compared. In an in vitro artificial mucus model, the densely PEGylated liposomes showed mucus permeability. Intracellular uptake of liposomes was evaluated in a Caco-2 and mucus-secreting Caco-2/HT29 co-culture. Intracellular uptake of MPPs was unaffected by mucus in the co-culture system, whereas the cellular uptake of GCS-liposomes was lower with a mucus layer than in Caco-2 alone. Rat in vivo oral absorption of liposomes was evaluated by using fluorescein isothiocyanate dextran (FD) as a model peptide drug. Oral absorption was higher for densely PEGylated than for unmodified liposomes and was PEG-concentration dependent, but excessive PEGylation decreased FD blood concentration. PEGylated liposomes incorporating spermine (SPM) as an absorption enhancer were then designed and showed the highest in vivo absorption of FD of all tested formulations. The pharmacological effects of the oral liposomes were evaluated by using elcatonin and did not correlate with FD oral absorption. The non-PEGylated SPM liposomes showed the highest pharmacological effect, suggesting the need for drug-specific optimization of liposomal components and surface modifiers.

Understanding the Factors Influencing Chitosan-Based Nanoparticles-Protein Corona Interaction and Drug Delivery Applications

Chitosan is a polymer that is extensively used to prepare nanoparticles (NPs) with tailored properties for applications in many fields of human activities. Among them, targeted drug delivery, especially when cancer therapy is the main interest, is a major application of chitosan-based NPs. Due to its positive charges, chitosan is used to produce the core of the NPs or to cover NPs made from other types of polymers, both strategies aiming to protect the carried drug until NPs reach the target sites and to facilitate the uptake and drug delivery into these cells. A major challenge in the design of these chitosan-based NPs is the formation of a protein corona (PC) upon contact with biological fluids. The composition of the PC can, to some extent, be modulated depending on the size, shape, electrical charge and hydrophobic / hydrophilic characteristics of the NPs. According to the composition of the biological fluids that have to be crossed during the journey of the drug-loaded NPs towards the target cells, the surface of these particles can be changed by covering their core with various types of polymers or with functionalized polymers carrying some special molecules, that will preferentially adsorb some proteins in their PC. The PC's composition may change by continuous processes of adsorption and desorption, depending on the affinity of these proteins for the chemical structure of the surface of NPs. Beside these, in designing the targeted drug delivery NPs one can take into account their toxicity, initiation of an immune response, participation (enhancement or inhibition) in certain metabolic pathways or chemical processes like reactive oxygen species, type of endocytosis of target cells, and many others. There are cases in which these processes seem to require antagonistic properties of nanoparticles. Products that show good behavior in cell cultures may lead to poor in vivo results, when the composition of the formed PC is totally different. This paper reviews the physico-chemical properties, cellular uptake and drug delivery applications of chitosan-based nanoparticles, specifying the factors that contribute to the success of the targeted drug delivery. Furthermore, we highlight the role of the protein corona formed around the NP in its intercellular fate.

Preparation of Hybrid Alginate-Chitosan Aerogel as Potential Carriers for Pulmonary Drug Delivery

This study aims to prepare hybrid chitosan-alginate aerogel microparticles without using additional ionic crosslinker as a possible pulmonary drug delivery system. The microparticles were prepared using the emulsion gelation method. The effect of the mixing order of the biopolymer within the emulsion and the surfactant used on final particle properties were investigated. Physicochemical characterizations were performed to evaluate particle size, density, morphology, surface area, surface charge, and the crystallinity of the preparation. The developed preparation was evaluated for its acute toxicity in adult male Sprague-Dawley rats. Measurements of zeta potential suggest that the surface charge depends mainly on the surfactant type while the order of biopolymer mixing has less impact on the surface charge. Chitosan amphiphilic properties changed the hydrophilic-lipophilic balance (HLB) of the emulsifying agents. The specific surface area of the prepared microparticles was in the range of (29.36-86.20) m²/g with a mesoporous pore size of (12.48-13.38) nm and pore volume of (0.09-0.29) cm³/g. The calculated aerodynamic diameter of the prepared particles was in the range of (0.17-2.29 µm). Toxicity studies showed that alginate-chitosan carrier developed herein caused mild lung inflammation with some renal and hepatic toxicities.

[Non-coding Natural Antisense RNA: Mechanisms of Action in the Regulation of Target Gene Expression and Its Clinical Implications]

Recent advances in high-throughput technologies have revealed that 75% of the human genome is transcribed to RNA, whereas only 3% of transcripts are translated into proteins. Consequently, many long non-coding RNAs (lncRNAs) have been identified, which has improved our understanding of the complexity of biological processes. LncRNAs comprise multiple classes of RNA transcripts that regulate the transcription, stability and translation of protein-coding genes in a genome. Natural antisense transcripts (NATs) form one such class, and the GENCODE v30 catalog contains 16193 lncRNA loci, of which 5611 are antisense loci. This review outlines our emerging understanding of lncRNAs, with a particular focus on how lncRNAs regulate gene expression using interferon-α1 (IFN-α1) mRNA and its antisense partner IFN-α1 antisense (as)RNA as an example. We have identified and characterized the asRNA that determines post-transcriptional IFN-α1 mRNA levels. IFN-α1 asRNA stabilizes IFN-α1 mRNA by cytoplasmic sense-antisense duplex formation, which may enhance the accessibility of an RNA stabilizer protein or decrease the affinity of an RNA decay factor for the RNA. IFN-α1 asRNA can also act as competing molecules in the competing endogenous (ce)RNA network with other members of the IFNA multigene family mRNAs/asRNAs, and other cellular mRNA transcripts. Furthermore, antisense oligoribonucleotides representing functional domains of IFN-α1 asRNA inhibit influenza virus proliferation in the respiratory tract of virus-infected animals. Thus, these findings support, at least in part, the rationale that dissecting the activity of NAT on gene expression regulation promises to reveal previously unanticipated biology, with potential to provide new therapeutic approaches to diseases.

Chrysin-loaded PLGA attenuates OVA-induced allergic asthma by modulating TLR/NF-κB/NLRP3 axis

Asthma, one of the significant public health problems, is triggered by certain inflammatory processes in the airways that are not addressed propitiously by current therapies. Though pieces of evidence on allergic asthma mitigation by the anti-inflammatory bioflavonoid chrysin (CHR) are accumulating, poor bioavailability, and low solubility curtail drug development. To overcome these shortcomings, CHR loaded nanoparticle (CHR-NP) was formulated, and its salutary effect in preclinical murine allergic asthma model via the peroral route was evaluated. The spherical nanosized particles showed slow, sustained release in vitro. Moreover, CHR-NP dramatically reduced the serum IgE, ovalbumin (OVA)-induced lung histological alteration, as well as Th2 (T-helper 2) cytokines in the bronchoalveolar lavage fluid (BALF). It also suppressed the elevated serum pro-inflammatory cytokines and their upstream TLR/NF-κB/NLRP3 pathway activation in lung superior to CHR and almost identical to dexamethasone (DEX). Thus this study suggests the potentiality of CHR-NP in ameliorating allergic asthma progression.

Controlled release and enhanced biological activity of chitosan-fabricated carbenoxolone nanoparticles

Nanotechnology based antimicrobial drugs are developed to enhance their properties to combat multidrug resistant microbes. Carbenoxolone (CBX) is a semi-synthetic derivate of a natural substance from the licorice plant, with anti- (inflammatory, fungal, viral, microbial, fibrotic and cancer) properties. Though used to treat gastric ulcers, its low aqueous stability, low bioavailability and toxicity limited the drug's utility. To enhance its antimicrobial activity and reduce cytotoxicity, a controlled release nanoformulation was developed using natural biodegradable polymer chitosan (CS) as a carrier which is biocompatible, nontoxic with placid antimicrobial property. UV-visible spectroscopy, electron microscopy, and Fourier transform infrared spectroscopy were used for characterization of the resultant CS-CBX nanoparticles (NPs). They were spherical with uniform dispersion, ~200 nm in size with surface charge of +18.6 mV and drug encapsulation of >80%. Drug release kinetics exhibited a controlled release of 86% over 36 h following zero order kinetics. The anti-microbial activity against common pathogenic Gram -ve and +ve bacteria and yeast increased ~2-fold with a concomitant 4-fold reduction in cytotoxicity assessed using human lung adeno carcinoma (A549) cells. This study demonstrates the affirmative aspects of CS-CBX NPs as a promising antibacterial agent and may facilitate repositioning of the drug for diverse applications.

Development, In Vitro Characterization, and In Vivo Toxicity Evaluation of Chitosan-Alginate Nanoporous Carriers Loaded with Cisplatin for Lung Cancer Treatment

Polysaccharide-based aerogels are promising drug carriers. Being nanoporous with a high specific surface area allows their use as a drug vehicle for various delivery routes. Intratracheal and intravenous administration of free cisplatin causes toxicity in the rat liver, lungs, and kidneys. In this work, microspherical particles based on alginate-chitosan without a traditional crosslinker were evaluated for targeted delivery of cisplatin by intratracheal administration. The aerogel particles were prepared using the emulsion gelation method, followed by supercritical carbon dioxide extraction. Loading of cisplatin on the prepared porous particles was performed by impregnation using supercritical fluid technology. The prepared carrier and the loaded drug were evaluated for drug content, release, and in vivo acute and subacute toxicity. Cisplatin was successfully loaded (percent drug loading > 76%) on the prepared carrier (particle size = 0.433 ± 0.091 μm) without chemically interacting with the carrier and without losing its crystal form. Sixty percent of cisplatin was released within 2 h, and the rest was loaded inside the polymer pores and had a sustained first-order release over 6 h. Loading cisplatin on the carrier developed herein reduced the cisplatin lung toxicity but increased the liver toxicity after intratracheal administration with nephrotoxicity being proportional to cisplatin dose in case of carrier-loaded cisplatin. Moreover, loading cisplatin on the carrier significantly reduced mortality rate and prevented weight loss in rats as compared to free cisplatin in subacute studies after intratracheal administration. Thus, the developed carrier showed high potential for targeted delivery of cisplatin for lung cancer treatment by inhalation. Graphical abstract.

NIR-dye based mucoadhesive nanosystem for photothermal therapy in breast cancer cells

Breast cancer is one of the leading causes of mortality in women, worldwide. The average survival rate of patients suffering from advanced breast cancer is about 27% for five years. Photothermal therapy employing biodegradable nanoparticle are extensively researched for enhanced anticancer therapy in breast cancer treatment. In the current study, we report a chitosan based mucoadherant and biodegradable niosome nanoparticle entrapping near infrared (NIR) dye (IR 806) for the treatment of breast cancer. Niosome entrapping IR 806 (NioIR) showed encapsulation efficacy of about 56 ± 2%. The prepared nanoparticles (NioIR) were further coated with chitosan (NioIR-C) to impart mucoadhesive property to the nanosystem. NioIR-C showed minimal degradation following NIR laser irradiation, thus enhancing its photothermal stability. They also exhibited efficient photothermal transduction, when compared with IR 806 dye. NioIR-C were biocompatible when treated with normal cell lines (NIH 3T3 and L929) and showed cytotoxicity towards breast cancer cell lines (MCF-7 and MDA-MB 231). When triggered with NIR laser, NioIR-C showed photothermal cell death (approximately 93%). The presence of chitosan coating on NioIR led to mucoadherence potential that further enhances the therapeutic effect on breast cancer cells when compared with IR 806 dye and NioIR. Thus NioIR-C can be a promising nanosystem for effective treatment of breast cancer using photothermal therapy.

Encapsulation of Oleuropein in Nanostructured Lipid Carriers: Biocompatibility and Antioxidant Efficacy in Lung Epithelial Cells

Oxidative damage has been linked to a number of diseases. Oleuropein (OLE), a natural occurring polyphenol from olive leaves (Olea europaea L.), is known to be a potent antioxidant compound with inherent instability and compromised bioavailability. Therefore, in this work, nanostructured lipid carriers (NLCs) were proposed for OLE encapsulation to protect and improve its antioxidant efficacy. The lipid matrix, composed of olive oil and Precirol, was optimized prior to OLE encapsulation. The characterization of the optimized oleuropein-loaded NLCs (NLC-OLE) showed a mean size of 150 nm, a zeta potential of −21 mV, an encapsulation efficiency of 99.12%, sustained release profile, and improved radical scavenging activity. The cellular in vitro assays demonstrated the biocompatibility of the NLCs, which were found to improve and maintain OLE antioxidant efficacy in the A549 and CuFi-1 lung epithelial cell lines, respectively. Overall, these findings suggest a promising potential of NLC-OLE to further design a pulmonary formulation for OLE delivery in lung epithelia.

How Can Biomolecules Improve Mucoadhesion of Oral Insulin? A Comprehensive Insight using Ex-Vivo, In Silico, and In Vivo Models

Currently, insulin can only be administered through the subcutaneous route. Due to the flaws associated with this route, it is of interest to orally deliver this drug. However, insulin delivered orally has several barriers to overcome as it is degraded by the stomach’s low pH, enzymatic content, and poor absorption in the gastrointestinal tract. Polymers with marine source like chitosan are commonly used in nanotechnology and drug delivery due to their biocompatibility and special features. This work focuses on the preparation and characterization of mucoadhesive insulin-loaded polymeric nanoparticles. Results showed a suitable mean size for oral administration (<600 nm by dynamic laser scattering), spherical shape, encapsulation efficiency (59.8%), and high recovery yield (80.6%). Circular dichroism spectroscopy demonstrated that protein retained its secondary structure after encapsulation. Moreover, the mucoadhesive potential of the nanoparticles was assessed in silico and the results, corroborated with ex-vivo experiments, showed that using chitosan strongly increases mucoadhesion. Besides, in vitro and in vivo safety assessment of the final formulation were performed, showing no toxicity. Lastly, the insulin-loaded nanoparticles were effective in reducing diabetic rats’ glycemia. Overall, the coating of insulin-loaded nanoparticles with chitosan represents a potentially safe and promising approach to protect insulin and enhance peroral delivery.

Antioxidant and Anti-Inflammatory Properties of Cherry Extract: Nanosystems-Based Strategies to Improve Endothelial Function and Intestinal Absorption

Cherry fruit has a high content in flavonoids. These are important diet components protecting against oxidative stress, inflammation, and endothelial dysfunction, which are all involved in the pathogenesis of atherosclerosis, which is the major cause of cardiovascular diseases (CVD). Since the seasonal availability of fresh fruit is limited, research has been focused on cherry extract (CE), which also possesses a high nutraceutical potential. Many clinical studies have demonstrated the nutraceutical efficacy of fresh cherries, but only a few studies on CE antioxidant and anti-inflammatory activities have been carried out. Here, the results concerning the antioxidant and anti-inflammatory activities of CE are reviewed. These were obtained by an in vitro model based on Human Umbilical Vein Endothelial Cells (HUVEC). To clarify the CE mechanism of action, cells were stressed to induce inflammation and endothelial dysfunction. Considering that antioxidants' polyphenol compounds are easily degraded in the gastrointestinal tract, recent strategies to reduce the degradation and improve the bioavailability of CE are also presented and discussed. In particular, we report on results obtained with nanoparticles (NP) based on chitosan derivatives (Ch-der), which improved the mucoadhesive properties of the chitosan polymers, as well as their positive charge, to favor high cellular interaction and polyphenols intestinal absorption, compared with a non-mucoadhesive negative surface charged poly(lactic-co-glycolic) acid NP. The advantages and safety of different nanosystems loaded with natural CE or other nutraceuticals are also discussed.

Development and in vitro characterization of polymeric nanoparticles containing recombinant adrenomedullin-2 intended for therapeutic angiogenesis

Cardiovascular diseases (CVD) are the leading cause of death worldwide. Growth factor therapy has emerged as novel therapeutic strategy under investigation for CVD. In this sense, adrenomedullin-2 (ADM-2) has been recently identified as a new angiogenic factor able to regulate the regional blood flow and cardiovascular function. However, the therapeutic value of ADM-2 is limited by its short biological half-life and low plasma stability. Poly (lactic-co-glycolic acid) (PLGA) micro- and nanoparticles have been investigated as growth factor delivery systems for cardiac repair. In this study, we aimed to develop PLGA nanoparticles containing ADM-2 intended for therapeutic angiogenesis. PLGA nanoparticles containing ADM-2 were prepared by a double emulsion modified method, resulting in 300 nm-sized stable particles with zeta potential around - 30 mV. Electron microscopy analysis by SEM and TEM revealed spherical particles with a smooth surface. High encapsulation efficiency was reached (ca.70%), as quantified by ELISA. ADM-2 associated to polymer nanoparticles was also determined by EDS elemental composition analysis, SDS-PAGE and LC-MS/MS for peptide identification. In vitro release assays showed the sustained release of ADM-2 from polymer nanoparticles for 21 days. Cell viability experiments were performed in J774 macrophages and H9c2 cardiomyocyte cells, about which PLGA nanoparticles loaded with ADM-2 did not cause toxicity in the range 0.01-1 mg/ml. Of note, encapsulated ADM-2 significantly induced cell proliferation in EA.hy926 endothelial cells, indicating the ADM-2 bioactivity was preserved after the encapsulation process. Collectively, these results demonstrate the feasibility of using PLGA nanoparticles as delivery systems for the angiogenic peptide ADM-2, which could represent a novel approach for therapeutic angiogenesis in CVD using growth factor therapy.

Synthesis and Imaging of Biocompatible Graphdiyne Quantum Dots

Graphdiyne has attracted much interest from researchers for their potential applications in energy storage, catalysis, and biomedical areas. As one of the derivatives of graphdiyne, graphdiyne quantum dots (GDQDs) may possess superior bioactivity due to active acetylene units. However, the biological application of biocompatible GDQDs have not been reported so far. Herein, GDQDs with uniform size and good crystallization were prepared via a classical solvothermal method. The GDQDs exhibit excitation- and pH-dependent fluorescence emission as well as superior photostability, demonstrating their potential for bioimaging. The GDQDs demonstrate efficient cellular uptake and cell imaging without induction of detectable cytotoxic effects in vitro. Systematical safety evaluation further confirmed good biocompatibility of the GDQDs in vivo. Our study preliminarily validates the application of the GDQDs in biomedicine and encourages more thorough studies for better realizing the potential of GDQDs.

Nanocrystal Formulation Improves Vaginal Delivery of CSIC for HIV Prevention

5-Chloro-3-phenylsulfonylindole-2-carboxamide (CSIC) is a highly potent non-nucleoside reverse transcriptase inhibitor (NNRTI) with potential for use in topical prophylaxis against HIV transmission. However, the hydrophobic nature of CSIC limits its administration through vaginal route. In this study, we developed nanocrystals of CSIC to potentially improve the aqueous solubility and intracellular uptake of CSIC in vitro and in vivo. CSIC nanocrystals were manufactured and stabilized with Pluronic F98 and hydroxypropyl methylcellulose E5. Transmission electron microscopy showed CSIC nanocrystals to be needle-like. Dynamic light scattering measurements showed a hydrodynamic size of 243 nm (polydispersity index < 0.3) and near neutral surface charge (- 7.8 mV). Particle size was maintained for at least 7 days in the liquid state and for at least 5 months after lyophilization. Drug content in the CSIC nanocrystal formulation (nanosuspension) was 0.8 mg/mL, which is 1000 times higher than the aqueous solubility of CSIC. In vitro release study showed that over 90% of CSIC was released from the nanocrystal formulation in a linear fashion over a period of 4 days. Importantly, CSIC nanocrystals showed equivalent cell-based anti-HIV activity (EC₅₀ ~ 1 nM) as that of non-formulated drug. In vitro studies demonstrated rapid macrophage uptake of CSIC nanocrystals via both energy-dependent (endocytosis) and independent processes. In vivo studies in Swiss Webster female mice showed that the nanocrystal formulation significantly improved CSIC delivery to mouse cervicovaginal tissues following intravaginal instillation. In summary, nanocrystals are a promising formulation approach for topical delivery of CSIC for protection against HIV sexual transmission.

Improved brain delivery of pueraria flavones via intranasal administration of borneol-modified solid lipid nanoparticles

Aim: To improve the drug delivery to the brain with borneol (Bo)-modified solid lipid nanoparticles (SLNs) of pueraria flavones (PTF) via intranasal administration. Materials & methods: PTF-loaded SLNs were modified with Bo by physical and chemical methods to synthesize PTF-Bo-SA-SLNs and PTF-Bo-SLNs. The prepared SLNs were characterized and their brain delivery effects were evaluated in vitro and in vivo. Results: There was a more pronounced accumulation of PTF-Bo-SA-SLNs in Caco-2 cells. Following intranasal administration, more coumarin-6 was found in the rat brain carried by Bo-SA-SLNs. Brain area under the curve and C_max of PTF-Bo-SA-SLN were 7.31- and 7.29-times higher than those of PTF-SLN, respectively. Conclusion: PTF-Bo-SA-SLNs are a promising therapeutic carrier for brain disease after intranasal administration.

Delivery of natural phenolic compounds for the potential treatment of lung cancer

The application of natural products to treat various diseases, such as cancer, has been an important area of research for many years. Several phytochemicals have demonstrated anticarcinogenic activity to prevent or reduce the progression of cancer by modulating various cellular mechanisms. However, poor bioavailability has hindered clinical success and the incorporation of these drugs into efficient drug delivery systems would be beneficial. For lung cancer, local delivery via the pulmonary route would also be more effective. In this article, recent in vitro scientific literature on phenolic compounds with anticancer activity towards lung cancer cell lines is reviewed and nanoparticulate delivery is mentioned as a possible solution to the problem of bioavailability. The first part of the review will explore the different classes of natural phenolic compounds and discuss recent reports on their activity on lung cancer cells. Then, the problem of the poor bioavailability of phenolic compounds will be explored, followed by a summary of recent advances in improving the efficacy of these phenolic compounds using nanoparticulate drug delivery systems. Graphical abstract The rationale for direct delivery of phenolic compounds loaded in microparticles to the lungs.

Exosomes derived from M1 macrophages aggravate neointimal hyperplasia following carotid artery injuries in mice through miR-222/CDKN1B/CDKN1C pathway

The role of M1 macrophages (M1M)-derived exosomes in the progression of neointimal hyperplasia remains unclear now. Using a transwell co-culture system, we demonstrated that M1M contributed to functional change of vascular smooth muscle cell (VSMC). We further stimulated VSMCs with exosomes isolated from M1M. Our results demonstrated that these exosomes could be taken up by VSMCs through macropinocytosis. Using a microRNA array assay, we identified that miR-222 originated from M1M-derived exosomes triggered the functional changes of VSMCs. In addition, we confirmed that miR-222 played a key role in promoting VSMCs proliferation and migration by targeting Cyclin Dependent Kinase Inhibitor 1B (CDKN1B) and Cyclin Dependent Kinase Inhibitor 1C (CDKN1C) in vitro. In vivo, M1M-derived exosomes significantly aggravated neointima formation following carotid artery ligation injury and wire injury and these effects were partly abolished by miR-222 inhibitor 2′OMe-miR-222. Our findings thus suggest that exosomes derived from M1M could aggravate neointimal hyperplasia through delivering miR-222 into VSMCs. Future studies are warranted to validate if the post-injury vascular neointimal hyperplasia and restenosis could be attenuated by inhibiting miR-222.

Transferrin-decorated thymoquinone-loaded PEG-PLGA nanoparticles exhibit anticarcinogenic effect in non-small cell lung carcinoma via the modulation of miR-34a and miR-16

The detailed molecular mechanism of transferrin-tagged thymoquinone nanoparticle mediated apoptotic induction in non-small cell lung carcinoma showing the involvement of p53 dependent synergistic activation of miR-34a and miR-16 in the pathway.

Chitosan Oleate Salt as an Amphiphilic Polymer for the Surface Modification of Poly-Lactic-Glycolic Acid (PLGA) Nanoparticles. Preliminary Studies of Mucoadhesion and Cell Interaction Properties

Most of the methods of poly-lactic-glycolic acid (PLGA) preparation involve the passage through the emulsification of a PLGA organic solution in water followed by solvent evaporation or extraction. The choice of the droplet stabilizer during the emulsion step is critical for the dimensions and the surface characteristics of the nanoparticles (NPs). In the present work, a recently described ionic amphiphilic chitosan derivative, chitosan oleate salt (CS-OA), was proposed for the first time to prepare PLGA NPs. A full factorial design was used to understand the effect of some formulation and preparation parameters on the NP dimensions and on encapsulation efficiency (EE%) of Nile red, used as a tracer. On the basis of the DoE study, curcumin loaded NPs were prepared, having 329 ± 42 nm dimensions and 68.75% EE%. The presence of a chitosan coating at the surface was confirmed by positive zeta potential and resulted in mucoadhesion behavior. The expected improvement of the interaction of the chitosan surface modified nanoparticles with cell membrane surface was confirmed in Caco-2 cell culture by the internalization of the loaded curcumin.

Targeted Brain Delivery of Rabies Virus Glycoprotein 29-Modified Deferoxamine-Loaded Nanoparticles Reverses Functional Deficits in Parkinsonian Mice

Excess iron deposition in the brain often causes oxidative stress-related damage and necrosis of dopaminergic neurons in the substantia nigra and has been reported to be one of the major vulnerability factors in Parkinson's disease (PD). Iron chelation therapy using deferoxamine (DFO) may inhibit this nigrostriatal degeneration and prevent the progress of PD. However, DFO shows very short half-life in vivo and hardly penetrates the blood brain barrier (BBB). Hence, it is of great interest to develop DFO formulations for safe and efficient intracerebral drug delivery. Herein, we report a polymeric nanoparticle system modified with brain-targeting peptide rabies virus glycoprotein (RVG) 29 that can intracerebrally deliver DFO. The nanoparticle system penetrates the BBB possibly through specific receptor-mediated endocytosis triggered by the RVG29 peptide. Administration of these nanoparticles significantly decreased iron content and oxidative stress levels in the substantia nigra and striatum of PD mice and effectively reduced their dopaminergic neuron damage and as reversed their neurobehavioral deficits, without causing any overt adverse effects in the brain or other organs. This DFO-based nanoformulation holds great promise for delivery of DFO into the brain and for realizing iron chelation therapy in PD treatment.

Characterization of rabies pDNA nanoparticulate vaccine in poloxamer 407 gel

Plasmid DNA (pDNA) vaccines have the potential for protection against a wide range of diseases including rabies but are rapid in degradation and poor in uptake by antigen-presenting cells. To overcome the limitations, we fabricated a pDNA nanoparticulate vaccine. The negatively charged pDNA was adsorbed onto the surface of cationic PLGA (poly (d, l-lactide-co-glycolide))-chitosan nanoparticles and were used as a delivery vehicle. To create a hydrogel for sustainable vaccine release, we dispersed the pDNA nanoparticles in poloxamer 407 gel which is liquid at 4 °C and turns into soft gels at 37 °C, providing ease of administration and preventing burst release of pDNA. Complete immobilization of pDNA to cationic nanoparticles was achieved at a pDNA to nanoparticles ratio (P/N) of 1/50. Cellular uptake of nanoparticles was both time and concentration dependent and followed a saturation kinetics with V_max of 11.389 µg/mL h and K_m of 139.48 µg/mL. The in vitro release studies showed the nanoparticulate vaccine has a sustained release for up to 24 days. In summary, pDNA PLGA-chitosan nanoparticles were non-cytotoxic, their buffering capacity and cell uptake were enhanced, and sustained the release of pDNA. We expect our pDNA vaccine's potency will be greatly improved in the animal studies.