Unlocking Transplant Tolerance with Biomaterials

For patients suffering from organ failure due to injury or autoimmune disease, allogeneic organ transplantation with chronic immunosuppression is considered the god standard in terms of clinical treatment. However, the true "holy grail" of transplant immunology is operational tolerance, in which the recipient exhibits a sustained lack of alloreactivity toward unencountered antigen presented by the donor graft. This outcome is resultant from critical changes to the phenotype and genotype of the immune repertoire predicated by the activation of specific signaling pathways responsive to soluble and mechanosensitive cues. Biomaterials have emerged as a medium for interfacing with and reprogramming these endogenous pathways toward tolerance in precise, minimally invasive, and spatiotemporally defined manners. By viewing seminal and contemporary breakthroughs in transplant tolerance induction through the lens of biomaterials-mediated immunomodulation strategies-which include intrinsic material immunogenicity, the depot effect, graft coatings, induction and delivery of tolerogenic immune cells, biomimicry of tolerogenic immune cells, and in situ reprogramming-this review emphasizes the stunning diversity of approaches in the field and spotlights exciting future directions for research to come.

Increased radical scavenging activity of thymoquinone and l-ascorbic acid dual encapsulated in palmitoyl-chitosan nanoparticles in a human normal lung fibroblast, MRC-5 due to synergistic antioxidative effects

Less effective antioxidant supplementation in combating free radicals is often related to the lack of the formulation of carriers. The antioxidant may be one of the most powerful substances but is marred by poor uptake by cells when the carrier degraded and dissolved too rapidly. Nanoparticle (NP) systems are promising in overcoming the problem since they provide high surface area to enhance encapsulation and release efficiency. With the right selection of material, NP carriers could function as constructive antioxidant cargos. Generally, NPs carry only one active ingredient; this study, however, utilized chitosan nanoparticles (CNPs) and hydrophobically modified palmitoyl-chitosan nanoparticles (PCNPs) that were dual encapsulated with antioxidants of different polarities, namely, hydrophobic thymoquinone (TQ) and hydrophilic l-ascorbic acid (LAA) to evaluate their combination effects in scavenging free radicals. The antioxidants followed zero-order release kinetics with a controlled release manner for about 48 h. The interaction effects between TQ and LAA loaded in the NP systems were determined by classical isobologram (CI) values. The CI values were derived by a diphenyl picrylhydrazyl (DPPH) assay, a radical scavenging activity assay. Combined TQ and LAA had CI values of less than one, with a lower value in the PCNP system than in the CNP system. This indicates that the interaction between those antioxidants showed higher synergistic effects in PCNPs, which enhanced the DPPH radical scavenging activities. The antioxidative potential of compound(s) encapsulated in the PCNP carrier was further experimented by a reactive oxygen species (ROS) assay on a human normal lung fibroblast cell line (MRC-5) as lung is one of the organs with high accumulation of free radicals. About 48 h post treatment, the dual-loaded TQ and LAA in PCNPs showed the lowest ROS level in comparison to single-loaded antioxidants and bare antioxidant delivery. The hydrogen peroxide (H2O2) radical scavenging was influenced by both the controlled release property of the PCNP system and the synergy between TQ and LAA. In short, dual-loaded TQ and LAA in the hydrophobically modified PCNP had effectively depicted the capability of a single CS-based nanocarrier to hold more than one compound at a time to function as a potent radical scavenger.

Metformin and curcumin co-encapsulated chitosan/alginate nanoparticles as effective oral carriers against pain-like behaviors in mice

Nanotechnology plays an integral role in multimodal analgesia. In this study, we co-encapsulated metformin (Met) and curcumin (Cur) into chitosan/alginate (CTS/ALG) nanoparticles (NPs) at their synergistic drug ratio by applying response surface methodology. The optimized Met-Cur-CTS/ALG-NPs were achieved with Pluronic® F-127 2.33% (w/v), Met 5.91 mg, and CTS:ALG mass ratio 0.05:1. The prepared Met-Cur-CTS/ALG-NPs had 243 nm particle size, -21.6 mV zeta potential, 32.6 and 44.2% Met and Cur encapsulations, 19.6 and 6.8% Met and Cur loading, respectively, and 2.9:1 Met:Cur mass ratio. Met-Cur-CTS/ALG-NPs displayed stability under simulated gastrointestinal (GI) fluid conditions and during storage. In vitro release study of Met-Cur-CTS/ALG-NPs in simulated GI fluids showed sustained release, with Met exhibiting Fickian diffusion and Cur demonstrating non-Fickian diffusion following the Korsmeyer-Peppas model. Met-Cur-CTS/ALG-NPs exhibited increased mucoadhesion and improved cellular uptake in Caco-2 cells. Additionally, Met-Cur-CTS/ALG-NPs exhibited better anti-inflammatory effects in lipopolysaccharide-stimulated RAW 264.7 macrophage and BV-2 microglial cells than the equivalent amount of the Met-Cur physical mixture, indicating a greater ability to modulate peripheral and central immune mechanisms of pain. In the mouse formalin-induced pain model, Met-Cur-CTS/ALG-NPs administered orally exhibited better attenuation of pain-like behaviors and proinflammatory cytokine release compared to the Met-Cur physical mixture. Furthermore, Met-Cur-CTS/ALG-NPs did not induce significant side effects in mice at therapeutic doses. Altogether, the present study establishes a CTS/ALG nano-delivery system for Met-Cur combination against pain with improved efficacy and safety.

Dual-Drug Delivery by Anisotropic and Uniform Hybrid Nanostructures: A Comparative Study of the Function and Substrate-Drug Interaction Properties

By utilizing nanoparticles to upload and interact with several pharmaceuticals in varying methods, the primary obstacles associated with loading two or more medications or cargos with different characteristics may be addressed. Therefore, it is feasible to evaluate the benefits provided by co-delivery systems utilizing nanoparticles by investigating the properties and functions of the commonly used structures, such as multi- or simultaneous-stage controlled release, synergic effect, enhanced targetability, and internalization. However, due to the unique surface or core features of each hybrid design, the eventual drug-carrier interactions, release, and penetration processes may vary. Our review article focused on the drug's loading, binding interactions, release, physiochemical, and surface functionalization features, as well as the varying internalization and cytotoxicity of each structure that may aid in the selection of an appropriate design. This was achieved by comparing the actions of uniform-surfaced hybrid particles (such as core-shell particles) to those of anisotropic, asymmetrical hybrid particles (such as Janus, multicompartment, or patchy particles). Information is provided on the use of homogeneous or heterogeneous particles with specified characteristics for the simultaneous delivery of various cargos, possibly enhancing the efficacy of treatment techniques for illnesses such as cancer.

Cytotoxic Effects of Nanoliposomal Cisplatin and Diallyl Disulfide on Breast Cancer and Lung Cancer Cell Lines

Dual drug delivery has become the choice of interest nowadays due to its increased therapeutic efficacy in targeting the tumor site precisely. As quoted in recent literature, it has been known to treat several cancers with an acute course of action. Even so, its use is restricted due to the drug’s low pharmacological activity, which leads to poor bioavailability and increases first-pass metabolism. To overcome these issues, a drug delivery system using nanomaterials which would not only encapsulate the drugs of interest but also carry them to the target site of action is needed. Given all these attributes, we have formulated dual drug-loaded nanoliposomes with cisplatin (cis-diamminedichloroplatinum(II) (CDDP)), an effective anti-cancer drug, and diallyl disulfide (DADS), an organosulfur compound derived from garlic. The CDDP and DADS-loaded nanoliposomes (Lipo-CDDP/DADS) exhibited better physical characteristics such as size, zeta potential, polydispersity index, spherical shape, optimal stability, and satisfactory encapsulation percentage. The in vitro anti-cancer activity against MDA-MB-231 and A549 cell lines revealed that Lipo-CDDP/DADS showed significant efficacy against the cancer cell lines, depicted through cell nucleus staining. We conclude that Lipo-CDDP/DADS hold exceptional pharmacological properties with better anti-cancer activity and would serve as a promising formulation to treat various cancers.

The recent advancement in the PLGA-based thermo-sensitive hydrogel for smart drug delivery

To date, hydrogels have opened new prospects for potential applications for drug delivery. The thermo-sensitive hydrogels have the great potential to provide more effective and controllable release of therapeutic/bioactive agents in response to changes in temperature. PLGA is a safe FDA-approved copolymer with good biocompatibility and biodegradability. Recently, PLGA-based formulation have attracted a lot of interest for thermo-sensitive hydrogels. Thermo-sensitive PLGA-based hydrogels provide the delivery system with good spatial and temporal control, and have been widely applied in drug delivery. This review is focused on the recent progression of the thermo-sensitive and biodegradable PLGA-based hydrogels that have been reported for smart drug delivery to the different organs. Eventually, future perspectives and challenges of thermo-sensitive PLGA-based hydrogels are discussed briefly.

Locust Bean Gum: Processing, Properties and Food Applications

Locust bean gum is derived from the seed endosperm of the Ceratonia siliqua carob tree and is known as locust bean or carob gum. Food, medicines, paper, textile, oil drilling, and cosmetic sectors all use it as an ingredient. Hydrogen bonding with water molecules makes locust bean gum useful in industrial settings. In addition, its dietary fibre activity helps regulate numerous health issues, including diabetes, bowel motions, heart disease and colon cancer. Locust bean gum production, processing, composition, characteristics, culinary applications, and health advantages are the subject of this article.

Co-Encapsulation of l-Asparaginase and Etoposide in Dextran Nanoparticles for Synergistic Effect in Chronic Myeloid Leukemia Cells

Co-encapsulation of multiple therapeutic drugs in a single nanocarrier has the potential to enable synergistic interactions, increase drug efficacy, and reduce side effects. The enzyme l-asparaginase and the small molecule drug etoposide have a known synergistic effect against selected cancer types. However, both drugs differ significantly in size, molecular weight, and solubility, which often results in challenges when a simultaneous delivery is required. In this study, we present the co-encapsulation of a large hydrophilic enzyme l-asparaginase and the small hydrophobic drug etoposide into a biodegradable, biocompatible, and acid-responsive dextran-based nanoparticle system. These dual drug-loaded nanoparticles show an excellent cellular uptake in chronic myeloid leukemia (CML) K562 cells and a stepwise release of the cytotoxic payloads in a pH-dependent manner. In activity tests, the dual drug-loaded formulation has shown a significant effect on cell viability (down to 31%) compared to those incubated only with l-asparaginase (92%) or etoposide (82%) at a particle concentration of 125 μg∙mL^-1. These results show that the simultaneous co-delivery of these two drugs in K562 cells leads to synergistic cytotoxicity, indicating a great potential for the treatment of CML.

PLGA's Plight and the Role of Stealth Surface Modification Strategies in Its Use for Intravenous Particulate Drug Delivery

Numerous human disorders can benefit from targeted, intravenous (IV) drug delivery. Polymeric nanoparticles have been designed to undergo systemic circulation and deliver their therapeutic cargo to target sites in a controlled manner. Poly(lactic-co-glycolic) acid (PLGA) is a particularly promising biomaterial for designing intravenous drug carriers due to its biocompatibility, biodegradability, and history of clinical success across other routes of administration. Despite these merits, PLGA remains markedly absent in clinically approved IV drug delivery formulations. A prominent factor in PLGA particles' inability to succeed intravenously may lie in the hydrophobic character of the polyester, leading to the adsorption of serum proteins (i.e., opsonization) and a cascade of events that end in their premature clearance from the bloodstream. PEGylation, or surface-attached polyethylene glycol chains, is a common strategy for shielding particles from opsonization. Polyethylene glycol (PEG) continues to be regarded as the ultimate "stealth" solution despite the lack of clinical progress of PEGylated PLGA carriers. This review reflects on some of the reasons for the clinical failure of PLGA, particularly the drawbacks of PEGylation, and highlights alternative surface coatings on PLGA particles. Ultimately, a new approach will be needed to harness the potential of PLGA nanoparticles and allow their widespread clinical adoption.

Monocytes as a convergent nanoparticle therapeutic target for cardiovascular diseases

Due to the increasing population of individualswith cardiovascular diseases and related comorbidities, there is an increasing need for development of synergistic therapeutics. Monocytes are implicated in a broad spectrum of diseases and can serve as a focal point for therapeutic targeting. This review discusses the role of monocytes in cardiovascular diseases and highlights trends in monocyte targets nanoparticles in three cardiovascular-related diseases: Diabetes, Atherosclerosis, and HIV. Finally, the review offers perspectives on how to develop nanoparticle monocyte targeting strategies that can be beneficial for treating co-morbidities.

Construction of a dual-responsive dual-drug delivery platform based on the hybrids of mesoporous silica, sodium hyaluronate, chitosan and oxidized sodium carboxymethyl cellulose

An intelligent drug delivery platform based on the hybrids of mesoporous silica nanoparticles (MSN), sodium hyaluronate (HA), chitosan (CS) and oxidized sodium carboxymethyl cellulose (oxCMC) is developed, which can be used for dual-responsive dual-drug delivery. Hydrophilic cytarabine (Cyt) is first loaded into the mesopores of the aminated MSN (NH₂-MSN), which is encapsulated by the hydrogel of HA and cystamine (Cys) crosslinked via amidation. The Cyt encapsulated hydrogel which is denoted as Cyt/NH₂-MSN/HA is co-encapsulated with hydrophobic methotrexate (MTX) into the hydrogel of CS and oxCMC resulted from Schiff base reaction. Since the acylhydrazone bonds (-HC=N-) between CS and oxCMC are sensitive to pH and the disulfide bonds (-S-S-) in Cys are sensitive to glutathione (GSH), the resultant dual-drug encapsulated hydrogel, denoted as Cyt/NH₂-MSN/HA/MTX/CS/oxCMC, can be used for dual-responsive (pH and GSH) drug delivery. The results of cell viability demonstrate that the developed dual-drug encapsulated hydrogel has significantly higher efficacy of chemotherapy than that of single-drug (MTX or Cyt) encapsulated hydrogel.

Development, Characterization, and Evaluation of α-Mangostin-Loaded Polymeric Nanoparticle Gel for Topical Therapy in Skin Cancer

The aim of this study was to prepare and evaluate α-mangostin-loaded polymeric nanoparticle gel (α-MNG-PLGA) formulation to enhance α-mangostin delivery in an epidermal carcinoma. The poly (D, L-lactic-co-glycolic acid) (PLGA) nanoparticles (NPs) were developed using the emulsion-diffusion-evaporation technique with a 3-level 3-factor Box-Behnken design. The NPs were characterized and evaluated for particle size distribution, zeta potential (mV), drug release, and skin permeation. The formulated PLGA NPs were converted into a preformed carbopol gel base and were further evaluated for texture analysis, the cytotoxic effect of PLGA NPs against B16-F10 melanoma cells, and in vitro radical scavenging activity. The nanoscale particles were spherical, consistent, and average in size (168.06 ± 17.02 nm), with an entrapment efficiency (EE) of 84.26 ± 8.23% and a zeta potential of -25.3 ± 7.1 mV. Their drug release percentages in phosphate-buffered solution (PBS) at pH 7.4 and pH 6.5 were 87.07 ± 6.95% and 89.50 ± 9.50%, respectively. The release of α-MNG from NPs in vitro demonstrated that the biphasic release system, namely, immediate release in the initial phase, was accompanied by sustained drug release. The texture study of the developed α-MNG-PLGA NPs gel revealed its characteristics, including viscosity, hardness, consistency, and cohesiveness. The drug flux from α-MNG-PLGA NPs gel and α-MNG gel was 79.32 ± 7.91 and 16.88 ± 7.18 µg/cm2/h in 24 h, respectively. The confocal study showed that α-MNG-PLGA NPs penetrated up to 230.02 µm deep into the skin layer compared to 15.21 µm by dye solution. MTT assay and radical scavenging potential indicated that α-MNG-PLGA NPs gel had a significant cytotoxic effect and antioxidant effect compared to α-MNG gel (p < 0.05). Thus, using the developed α-MNG-PLGA in treating skin cancer could be a promising approach.

Smart gating porous particles as new carriers for drug delivery

The design of smart drug delivery carriers has recently attracted great attention in the biomedical field. Smart carriers can specifically respond to physical and chemical changes in their environment, such as temperature, photoirradiation, ultrasound, magnetic field, pH, redox species, and biomolecules. This review summarizes recent advances in the integration of porous particles and stimuli-responsive gatekeepers for effective drug delivery. Their unique structural properties play an important role in facilitating the diffusion of drug molecules and cell attachment. Various techniques for fabricating porous materials, with their major advantages and limitations, are summarized. Smart gatekeepers provide advanced functions such as "open-close" switching by functionalized stimuli-responsive polymers on a particle's pores. These controlled delivery systems enable drugs to be targeted at specific rates, time programs, and sites of the human body. The gate structures, gating mechanisms, and controlled release mechanisms of each trigger are detailed. Current ongoing research and future trends in targeted drug delivery, tissue engineering, and regenerative medicine applications are highlighted.

Ophthalmic Sensors and Drug Delivery

Advances in multifunctional materials and technologies have allowed contact lenses to serve as wearable devices for continuous monitoring of physiological parameters and delivering drugs for ocular diseases. Since the tear fluids comprise a library of biomarkers, direct measurement of different parameters such as concentration of glucose, urea, proteins, nitrite, and chloride ions, intraocular pressure (IOP), corneal temperature, and pH can be carried out non-invasively using contact lens sensors. Microfluidic contact lens sensor based colorimetric sensing and liquid control mechanisms enable the wearers to perform self-examinations at home using smartphones. Furthermore, drug-laden contact lenses have emerged as delivery platforms using a low dosage of drugs with extended residence time and increased ocular bioavailability. This review provides an overview of contact lenses for ocular diagnostics and drug delivery applications. The designs, working principles, and sensing mechanisms of sensors and drug delivery systems are reviewed. The potential applications of contact lenses in point-of-care diagnostics and personalized medicine, along with the significance of integrating multiplexed sensing units together with drug delivery systems, have also been discussed.

Dual VP28 and VP37 dsRNA encapsulation in IHHNV virus-like particles enhances shrimp protection against white spot syndrome virus

Accumulative evidence of using double stranded (ds) RNA encapsulated into virus like particle (VLP) nanocarrier has open feasibility to fight against shrimp viral infection in aquaculture field. In this study, we co-encapsulated VP37 and VP28 dsRNA into hypodermal and hematopoietic necrosis virus (IHHNV) like particle and investigated its protection against white spot syndrome virus (WSSV). Five micrograms of each dsRNA were used as starting materials to load into VLP, while the loading efficiency was slightly different, i.e, VP37 dsRNA had somewhat a better load into VLP's cavity. It was apparent that co-encapsulation of dual dsRNA showed a superior WSSV silencing ability than the single dsRNA counterpart as evidence by the lower WSSV gene expression and its copy number in the gill tissues. Besides, we also demonstrated that co-encapsulated dual dsRNA into IHHNV-VLP stimulated the increased number of hemocytes and the corresponding PO activity as well as up-regulated proPO gene expression in hemocytes to resist viral invasion after an acute stage of WSSV infection. This synergistic action of dual dsRNA encapsulated into IHHNV-VLPs could thus act to delay time of shrimp death and reduced shrimp cumulative mortality greater than the single, naked dsRNA treatment and positive control groups. The obtaining results would encourage the feasibility to use it as a new weapon to fight WSSV infection in shrimp aquaculture.

The key role of the drug self-aggregation ability to obtain optimal nanocarriers based on aromatic-aromatic drug-polymer interactions

The efficient association and controlled release of hydrophilic and aromatic low molecular-weight drugs (HALMD) still remains a challenge due to their relatively weak interactions with excipients and strong affinity to water. Considering that a wide variety of drugs to treat chronic diseases are HALMD, their inclusion in polymeric nanoparticles (NPs) constitutes an attractive possibility by providing to these drugs with controllable physiochemical properties, preventing crisis episodes, decreasing dose-dependent side effects and promoting therapeutic adhesiveness. However, the strong interaction of HALMD with the aqueous medium jeopardizes their encapsulation and controlled release. In this work, the role of the self-assembly tendency of HALMD on their association with the aromatic excipient poly(sodium 4-styrensulfonate) (PSS) to form NPs is studied. For this aim, the widely used drugs amitriptyline (AMT), promethazine (PMZ), and chlorpheniramine (CPM) are selected due to their well described critical aggregation concentration (cac) (36 mM for AMT, 36 mM for PMZ, and 69.5 mM for CPM). These drugs undergo aromatic-aromatic interactions with the polymer, which stabilize their mutual binding, as seen by NMR. The simple mixing of solutions of opposite charged molecules (drug + PSS) allowed obtaining NPs. Importantly, comparing the three drugs, the formation of NPs occurred at significantly lower absolute concentration and significantly lower drug/polymer ratio as the cac takes lower values, indicating a stronger binding to the polymer, as also deduced from the respective drug/polymer dissociation constant values. In addition, the number of formed NPs is similar for all formulations, even though a much lower concentration of the drug and polymer is present in systems comprising lower cac. The obtained NPs are spheroidal and present size between 100 and 160 nm, low polydispersity (≤0.3) and negative zeta potential (from -30 to -60 mV). The association efficiency reaches values ≥ 83% and drug loading could achieve values up to 68% (never evidenced before for systems comprising HALMD). In addition, drug release studies are also significantly influenced by cac, providing more prolonged release for AMT and PMZ (lower cac), whose delivery profiles adjust to the Korsmeyer-Peppas equation. As a novelty of this work, a synergic contribution of drug self-association tendency and aromatic-aromatic interaction between the drug and polymers is highlighted, a fact that could be crucial for the rational design and development of efficient drug delivery systems.

Metallo-Liposomes Derived from the [Ru(bpy)3]2+ Complex as Nanocarriers of Therapeutic Agents

The obtaining of nanocarriers of gene material and small drugs is still an interesting research line. Side-effects produced by the toxicity of several pharmaceutics, the high concentrations needed to get therapeutic effects, or their excessive use by patients have motivated the search for new nanostructures. For these reasons, cationic metallo-liposomes composed by phosphatidylcholine (PC), cholesterol (CHO) and RuC1C19 (a surfactant derived from the metallic complex [Ru(bpy)3]2+) were prepared and characterized by using diverse techniques (zeta potential, dynamic light scattering and electronic transmission microscopy –TEM-). Unimodal or bimodal populations of spherical aggregates with small sizes were obtained depending on the composition of the liposomes. The presence of cholesterol favored the formation of small aggregates. ct-DNA was condensed in the presence of the liposomes investigated. In-vitro assays demonstrated the ability of these nanoaggregates to internalize into different cell lines. A positive gene transfection into human bone osteosarcoma epithelial cells (U2OS) was also observed. The RuC1C19 surfactant was used as sensor to quantify the binding of DNA to the liposomes. Doxorubicin was encapsulated into the metallo-liposomes, demonstrating their ability to be also used as nanocarriers of drugs. A relationship between then encapsulation percentage of the antibiotic and the composition of the aggregates has been established.

Development of L-carnosine functionalized iron oxide nanoparticles loaded with dexamethasone for simultaneous therapeutic potential of blood brain barrier crossing and ischemic stroke treatment

The development of suitable drug delivery carriers is significant in biomedical applications to improve the therapeutic efficiency. Recent progress in nanotechnological fields, paved the way for the formulation of variety of drug carriers. The brain disorders such as ischemic stroke, brain cancer, and CNS disorders were poorly treated due to the presence of blood brain barrier that hinders the passage of drugs to the brain. Hence, the formulated drugs should have the ability to cross the blood-brain barrier (BBB) for ischemic stroke treatment. In the present work, we have synthesized PLGA functionalized magnetic Fe₃O₄ nanoparticle (MNP) with L-carnosine peptide (LMNP) composite loaded with dexamethasone (dm@LMNP) and demonstrated as efficient drug delivery platform for simultaneous BBB crossing and treatment of ischemic stroke. The surface morphology, particles size and zeta potential of the prepared material was studied from SEM, PSD, PDI and TEM analyses. The drug loading of dexamethasone in LMNP (dm@LMNP) vesicles was found to be 95.6 ± 0.2%. The in vitro drug release kinetics displayed that prepared composited LMNP material provides controlled and sustainable releasing efficiency at pH 7.4 and 5.8 when compared to the PLGA NPs and free dexamethasone drug molecules. The cytotoxicity and the biocompatibility test results were found to be satisfactory. The L-carnosine loaded nano-formulation has been greatly leads to effective BBB crossing to access the brain tissues. These results showed that the Fe₃O₄ nanoparticles/PLGA polymer can be used as an effective drug carrier for the treatment of stroke and simultaneous blood brain barrier crossing.

PEG-b-PLGA Nanoparticles Loaded with Geraniin from Phyllanthus Watsonii Extract as a Phytochemical Delivery Model

The study outlined a standardized double emulsion method for simple poly(ethylene glycol)-block-poly(lactic-co-glycolic acid) (PEG-b-PLGA) nanoparticle (NP) synthesis. The PEG-b-PLGA NP was also used for entrapment of geraniin as a simple model system for phytochemical delivery. PEG-b-PLGA NPs were prepared using the double emulsion method. The yields and particle sizes of PEG-b-PLGA NPs obtained with and without encapsulation of geraniin were 57.6% and 134.20 ± 1.45 nm and 66.7% and 102.70 ± 12.36 nm, respectively. High-performance liquid chromatography of geraniin that was extracted from Phyllanthus watsonii was detected at 64 min. Geraniin burst release began at 40 min and fully released at 3 h. PEG-b-PLGA NP was non-cytotoxic, while cytotoxicity of geraniin was dose dependant towards normal human epithelial colon cells, CCD 841 CoN cells.

Development of 6-Thioguanine conjugated PLGA nanoparticles through thioester bond formation: Benefits of electrospray mediated drug encapsulation and sustained release in cancer therapeutic applications

Polymeric nanoparticle-based successful delivery of hydrophobic drugs is highly desirable for its controlled and sustained release at the disease site, which is a challenge with the current synthesis methods. In the present study, an electrospray mediated facile one-step synthesis approach is explored in which a solution mixture of a hydrophobic drug, 6-thioguanine (Tg) and a biocompatible FDA approved polymer, Poly (d, l-lactide-co-glycolide) (PLGA) is injected in an applied electric field of suitable intensity to prepare drug encapsulated PLGA nanoparticles, PLGA-Tg with high yield. In order to explore the effect of external electric field on Tg loading and delivery applications, the nanoparticles are characterized using EDX, AFM, FESEM, TEM, FTIR, Raman, fluorescence, and mass spectroscopy techniques. The characterization studies indicate that the electric field mediated synthesis exhibits spherical nanoparticles with a homogenous core size distribution of ~60 nm, high encapsulation (~97.22%) and stable conjugation of Tg (via thioester linkages) with PLGA molecules in the presence of the applied electric field. The kinetic study demonstrates the 'anomalous diffusion' (non-Fickian diffusion) release mechanism in which Tg escapes from PLGA matrix with a slow, but steady diffusion rate and the sustained drug release profile continues for 60 days. To check the biological activity of the encapsulated Tg, in-vitro cell studies of the PLGA-Tg are performed on HeLa cells. The MTT assay shows significant cell death after 48 h of treatment, and the cellular internalization of the drug-loaded nanoparticles occurs through pinocytosis mediated uptake, which is established by the AFM analysis. The Raman and mass spectroscopy studies suggest that the PLGA-Tg nanoparticles are rapidly hydrolyzed inside cell cytoplasm to release Tg which initiates apoptosis-mediated cell death confirmed by as DNA fragmentation and membrane blebbing studies. The results clearly emphasize the benefits of electrospray based synthesis of polymeric nanodrug formulation through the formation of chemical bonds between polymer and drug molecules that could be easily implemented in the design and development of an effective nanotherapeutic platform with no typical 'burst effect,' prolonged release profile, and significant toxicity to the cancer cells.

PLGA nanodepots co-encapsulating prostratin and anti-CD25 enhance primary natural killer cell antiviral and antitumor function

Natural killer (NK) cells are attractive effector cells of the innate immune system against human immunodeficiency virus (HIV) and cancer. However, NK cell therapies are limited by the fact that target cells evade NK cells, for example, in latent reservoirs (in HIV) or through upregulation of inhibitory signals (in cancer). To address this limitation, we describe a biodegradable nanoparticle-based "priming" approach to enhance the cytotoxic efficacy of peripheral blood mononuclear cell-derived NK cells. We present poly(lactic-co-glycolic acid) (PLGA) nanodepots (NDs) that co-encapsulate prostratin, a latency-reversing agent, and anti-CD25 (aCD25), a cell surface binding antibody, to enhance primary NK cell function against HIV and cancer. We utilize a nanoemulsion synthesis scheme to encapsulate both prostratin and aCD25 within the PLGA NDs (termed Pro-aCD25-NDs). Physicochemical characterization studies of the NDs demonstrated that our synthesis scheme resulted in stable and monodisperse Pro-aCD25-NDs. The NDs successfully released both active prostratin and anti-CD25, and with controllable release kinetics. When Pro-aCD25-NDs were administered in an in vitro model of latent HIV and acute T cell leukemia using J-Lat 10.6 cells, the NDs were observed to prime J-Lat cells resulting in significantly increased NK cell-mediated cytotoxicity compared to free prostratin plus anti-CD25, and other controls. These findings demonstrate the feasibility of using our Pro-aCD25-NDs to prime target cells for enhancing the cytotoxicity of NK cells as antiviral or antitumor agents.

Diclofenac sodium loaded PLGA nanoparticles for inflammatory diseases with high anti-inflammatory properties at low dose: Formulation, characterization and in vivo HET-CAM analysis

The development of a new drug active substance is not only time-consuming and expensive, but also a chain of operations that often fails. However, increasing the bioavailability, effectiveness, safety, or targeting the drugs used in clinic by various methods, such as nanoparticles (NPs), may be a more effective way of using them in clinic. In addition, NP formulations are becoming increasingly popular in modern medical treatments. Angiogenesis, formation of new capillaries from a pre-existing one, fundamentally occurs in physiological processes such as wound healing, embryogenesis and menstrual cycle, also has a vital role in pathology of cancer, psoriasis, diabetic retinopathy and chronic inflammation. The Hen's Egg Test on the Chorioallantoic Membrane (HET-CAM) assay is a useful, well established and animal alternative in vivo procedure for evaluation of anti-inflammatory potentials and anti-irritant properties of nano drug delivery systems. In this study, diclofenac sodium (DS) loaded PLGA NPs were prepared and characterized. The particle size (PS) of DS-loaded PLGA NPs was between 114.7 and 124.8 nm and all NPs were monodisperse with negative zeta potential values. The encapsulation efficiency was in range of 41.4-77.8%. In vitro dissolution studies of NPs showed up to 24 h of DS release after the first 3 h of burst effect. The 3 h burst effect and 24 h release kinetics studied with DDSolver were found to be predominantly driven not only by one mechanism, by a combined mechanism of Fickian and non-Fickian. Solid state structures of formulations were clarified by DSC and FT-IR analysis. PS, EE% and release rates were found to be affected by the amount of DS added to the formulations. Increasing the amount of DS added to the formulations increased PS, while the EE% decreased. The release rates were affected by PS and the formulation with the lowest PS value showed slower release. The anti-inflammatory activity of optimum formulation (NP-1) was examined using in vivo HET-CAM assay. The anti-inflammatory activity results indicated that NP-1 coded NP formulation showed significantly good anti-inflammatory potential at low dose. As a result, a low dose high anti-inflammatory effect was achieved with the NP structure of DS. To the best of our knowledge this is the first study on in vivo anti-inflammatory activities of DS loaded PLGA NPs by HET-CAM.

Recent advances in the combination delivery of drug for leukemia and other cancers

Introduction: Combination therapy has been explored for its potential to reduce or eliminate multidrug resistance in treating different types of cancer including leukemia. Nutraceutical, small molecular drugs, and small interfering ribonucleic acid (siRNA) are some of the effective drugs. In order to avoid off-site targeting, reduce the dosage required, and increase the half-life of the drug in the circulation system, drug delivery vehicles, such as nanoparticles and microfibers have been explored.Areas covered: This review summarizes various therapies utilized in treating leukemia based on their effectiveness in inducing protein inhibition and/or apoptosis. In particular, treatment effectiveness using combination therapy using various devices is addressed. Recently explored drug delivery methods are reviewed, providing examples and their applications in cancer treatment. The drug listing, delivery systems classifications, along with the general modeling approach in this review, provide, to a full extent, a basis for cancer drug delivery future studies.Expert opinion: The reviewer's opinion tackles the potential of using a multi-delivery system to deliver multiple drugs, providing better control upon drug release and targeting. Both local and systemic delivery are considered and explored for their potential targets. Researchers are advised to pre-consider all aspects associated with their desired delivery method.

Airway epithelial-targeted nanoparticles for asthma therapy

Asthma is a common chronic inflammatory disease associated with intermittent airflow obstruction caused by airway inflammation, mucus overproduction, and bronchial hyperresponsiveness. Despite current treatment and management options, a large number of patients with asthma still have poorly controlled disease and are susceptible to acute exacerbations, usually caused by a respiratory virus infection. As a result, there remains a need for novel therapies to achieve better control and prevent/treat exacerbations. Nanoparticles (NPs), including extracellular vesicles (EV) and their synthetic counterparts, have been developed for drug delivery in respiratory diseases. In the case of asthma, where airway epithelium dysfunction, including dysregulated differentiation of epithelial cells, impaired barrier, and immune response, is a driver of disease, targeting airway epithelial cells with NPs may offer opportunities to repair or reverse these dysfunctions with therapeutic interventions. EVs possess multiple advantages for airway epithelial targeting, such as their natural intrinsic cell-targeting properties and low immunogenicity. Synthetic NPs can be coated with muco-inert polymers to overcome biological barriers such as mucus and the phagocytic response of immune cells. Targeting ligands could be also added to enhance targeting specificity to epithelial cells. The review presents current understanding and advances in NP-mediated drug delivery to airway epithelium for asthma therapy. Future perspectives in this therapeutic strategy will also be discussed, including the development of novel formulations and physiologically relevant preclinical models.

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.

Poly(hydroxybutyrate-co-hydroxyvalerate) microparticles embedded in κ-carrageenan/locust bean gum hydrogel as a dual drug delivery carrier

A novel composite hydrogel was prepared as a dual drug delivery carrier. Poly(hydroxybutyrate-co-hydroxyvalerate) (PHBV) microparticles were prepared to encapsulate simultaneously ketoprofen and mupirocin, as hydrophobic drug models. These microparticles were embedded in a physically crosslinked hydrogel of κ-carrageenan/locust bean gum. This composite hydrogel showed for both drugs a slower release than the obtained release from microparticles and hydrogel separately. The release of both drugs was observed during a period of 7 days at 37 °C. Different kinetic models were analyzed and the results indicated the best fitting to a Higuchi model suggesting that the release was mostly controlled by diffusion. Also, the drug loaded microparticles were spherical with average mean particle size of 1.0 μm, mesoporous, and distributed homogeneously in the hydrogel. The composite hydrogel showed a thermosensitive swelling behavior reaching 183% of swelling ratio at 37 °C. The composite hydrogel showed the elastic component to be higher than the viscous component, indicating characteristics of a strong hydrogel. The biocompatibility was evaluated with in vitro cytotoxicity assays and the results indicated that this composite hydrogel could be considered as a potential biomaterial for dual drug delivery, mainly for wound healing applications.

Polymeric Core-Shell Combinatorial Nanomedicine for Synergistic Anticancer Therapy

Core-shell nanostructures are promising platforms for combination drug delivery. However, their complicated synthesis process, poor stability, surface engineering, and low biocompatibility are major hurdles. Herein, a carboxymethyl chitosan-coated poly(lactide-co-glycolide) (cmcPLGA) core-shell nanostructure is prepared via a simple one-step nanoprecipitation self-assembly process. Engineered core-shell nanostructures are tested for combination delivery of loaded docetaxel and doxorubicin in a cancer-mimicked environment. The drugs are compartmentalized in a shell (doxorubicin, Dox) and a core (docetaxel, Dtxl) with loading contents of ∼1.2 and ∼2.06%, respectively. Carboxymethyl chitosan with both amine and carboxyl groups act as a polyampholyte in diminishing ζ-potential of nanoparticles from fairly negative (-13 mV) to near neutral (-2 mV) while moving from a physiological pH (7.4) to an acidic tumor pH (6) that can help the nanoparticles to accumulate and release the drug on-site. The dual-drug formulation was found to carry a clinically comparable 1.7:1 weight ratio of Dtxl/Dox, nanoengineered for the sequential release of Dox followed by Dtxl. Single and engineered combinatorial nanoformulations show better growth inhibition toward three different cancer cells compared to free drug treatment. Importantly, Dox-Dtxl cmcPLGA nanoparticles scored synergism with combination index values between 0.2 and 0.3 in BT549 (breast ductal carcinoma), PC3 (prostate cancer), and A549 (lung adenocarcinoma) cell lines, demonstrating significant cell growth inhibition at lower drug concentrations as compared to single-drug control groups. The observed promising performance of dual-drug formulation is due to the G2/M phase arrest and apoptosis.

Application of statistical design to evaluate critical process parameters and optimize formulation technique of polymeric nanoparticles

In advanced medication, drug-loaded polymeric nanoparticles (NPs) appeared as a novel drug delivery system with lots of advantages over conventional medicines. Despite all the advantages, NPs do not gain popularity for manufacturing hurdles. The study focused on the formulation difficulties and implementation of statistical design to establish an effective model for manufacturing NPs. In this study, physico-chemical properties of the drug and polymer (PLGA) were incorporated to understand the mechanistic insights of nanoformulations. Primarily, the process controlling parameters were screened by Plackett-Burman design and the critical process parameters (Cpp) were further fabricated by Box-Behnken design (BBD). The TLM-PLGA-NPs (telmisartan loaded PLGA NPs) exhibited particle size, encapsulation efficiency and zeta potential of 232.4 nm, 79.21% and -9.92 mV respectively. The NPs represented drug loading of 76.31%. Korsmeyer-Peppas model (R 2 = 0.925) appeared to be the best fitted model for in vitro release kinetics of NPs. The model identified Fickian diffusion of TLM from the polymeric nanoparticles. The ANOVA results of variables indicate that BBD is a suitable model for the development of polymeric NPs. The study successfully identified and evaluated the correlation of significant parameters that were directly or indirectly influencing the formulations which deliberately produce desired nanoparticles with the help of statistical design.

Water and Oil Insoluble PEGDA-Based Microcapsule: Biocompatible and Multicomponent Encapsulation

Despite the recent development in various materials capable of encapsulating biomolecules, there exist limited reports on multicomponent encapsulation in biocompatible microcapsules. In this letter, we utilize the molecular weight dependent solubility of poly(ethylene glycol) diacrylate (PEGDA) and droplet microfluidics to achieve direct encapsulation of both hydrophilic and hydrophobic cargoes in PEG microcapsules. By using PEGDA 250 as the middle phase, we demonstrate that these PEGDA-based microcapsules allow simultaneous encapsulation of both hydrophilic and hydrophobic cargoes. We further confirm the validity of this approach by demonstrating that complex biomolecule such as protein can be effectively encapsulated within these PEGDA-based microcapsules.

Therapeutic Contact Lenses with Polymeric Vehicles for Ocular Drug Delivery: A Review

The eye has many barriers with specific anatomies that make it difficult to deliver drugs to targeted ocular tissues, and topical administration using eye drops or ointments usually needs multiple instillations to maintain the drugs’ therapeutic concentration because of their low bioavailability. A drug-eluting contact lens is one of the more promising platforms for controllable ocular drug delivery, and, among various manufacturing methods for drug-eluting contact lenses, incorporation of novel polymeric vehicles with versatile features makes it possible to deliver the drugs in a sustained and extended manner. Using the diverse physicochemical properties of polymers for nanoparticles or implants that are selected according to the characteristics of drugs, enhancement of encapsulation efficiency and prolonged drug release are possible. Even though therapeutic contact lenses with polymeric vehicles allow us to achieve sustained ocular drug delivery, drug leaching during storage and distribution and the possibility of problems related to surface roughness due to the incorporated vehicles still need to be discussed before application in a real clinic. This review highlights the overall trends in methodology to develop therapeutic contact lenses with polymeric vehicles and discusses the limitations including comparison to cosmetically tinted soft contact lenses.

Rapid on-Chip Assembly of Niosomes: Batch versus Continuous Flow Reactors

The large-scale continuous production of niosomes remains challenging. The inherent drawbacks of batch processes such as large particle polydispersity and reduced batch-to-batch reproducibility are here overcome by using commercially available microfluidic reactors. Compared to the traditional batch-based film hydration method, herein, we demonstrate that it is possible to carry out the homogeneous, large-scale (up to 120 mg/min) production of niosomes using two different synthesis techniques (the thin film hydration method and the emulsification technique). Niosomes particle size can be controlled depending on the need by varying the synthesis temperature. The high cytocompatibility of the resulting niosomes was also demonstrated in this work on three different somatic cell lines. For the first time, the structure of the niosome multilamellar shell was also elucidated using high-resolution transmission electron microscopy (HR-STEM) as well as their colloidal stability over time (6 weeks) under different storage conditions. The morphology of cryo-protected or as-made niosomes was also evaluated by HR-STEM after freeze-drying. Finally, the dual ability of those synthetic, nonionic, surfactant-based vesicles to carry both hydrophilic and hydrophobic molecules was also here demonstrated by using laser scanning confocal microscopy.