Nanoparticles provide long-term stability of bevacizumab preserving its antiangiogenic activity

Controlled release of therapeutic antibody using hydrolytically degradable microgels

Monoclonal antibodies have gained significant interest as potential therapeutics for treating various diseases. However, these therapies are not always effective due to poor treatment compliance associated with multiple administrations and drug resistance. Thus, there is a growing interest in developing advanced monoclonal antibody delivery systems that can customize pharmacokinetics to enhance therapeutic outcomes. This work aimed to engineer hydrolytic 4-arm PEG maleimide (PEG-4MAL) microgels for the controlled delivery of therapeutic antibodies, specifically anti-angiogenic bevacizumab, to overcome the limitations of current monoclonal antibody therapies. Through a PEGylation reaction with a thiol-terminated PEG linker, the antibody was covalently conjugated to the macromer backbone before microgel synthesis. The PEGylation reaction was simple, effective, and did not affect antibody bioactivity. Antibody release kinetics was tuned by changing the concentration of the hydrolytic linker (0-2 mM) and/or PEG-4MAL:protein molar ratio (1000:1, 2000:1, and 5000:1) in the macromer precursor solution during microgel fabrication. The bioactivity of the released antibody was assessed on human umbilical endothelial vascular cells (HUVEC), demonstrating that extracts from hydrolytic microgels reduced cell proliferation over time. Collectively, this study demonstrates the development of highly tunable delivery platform based on degradable PEG-4MAL microgels that can be adapted for therapeutic antibody-controlled release.

Developing a synergistic rate-retarding polymeric implant for controlling monoclonal antibody delivery in minimally invasive glaucoma surgery

Monoclonal antibodies (mAbs) have garnered substantial attention within the field of ophthalmology and can be used to suppress scar formation after minimally invasive glaucoma surgeries. Here, by controlling mAb passive diffusion, we developed a polymeric, rate-controlling membrane reservoir loaded with poly(lactic-co-glycolic acid) microspheres to deliver mAb for several weeks. Different parameters were tested to ensure that the microspheres achieved a good quality characteristic, and our results showed that 1 %W/V emulsifier with 5 %W/V NaCl achieved mAb-loaded microspheres with the highest stability, encapsulation efficiency and minimal burst release. Then, we fabricated and compared 10 types of microporous films based on polylactic acid (PLA), polycaprolactone (PCL), and polyethylene glycol (PEG). Our results revealed distinct pore characteristics and degradation patterns in different films due to varying polymer properties, and all the polymeric film formulations showed good biocompatibility in both human trabecular meshwork cells and human conjunctival fibroblasts. Finally, the optimized microspheres were loaded into the reservoir-type polymeric implant assembled by microporous membranes with different surface coating modifications. The implant formulation, which was fabricated by 60 PCL: 40 PEG (3 %W/V) polymer with 0.1 %W/V poly(lactic-co-glycolic acid) barrier, exerted the best drug release profile that can sustained release mAb (83.6 %) for 4 weeks.

Infliximab microencapsulation: an innovative approach for intra-articular administration of biologics in the management of rheumatoid arthritis-in vitro evaluation

Microencapsulation of the therapeutical monoclonal antibody infliximab (INF) was investigated as an innovative approach to improve its stability and to achieve formulations with convenient features for intra-articular administration. Ultrasonic atomization (UA), a novel alternative to microencapsulate labile drugs, was compared with the conventional emulsion/evaporation method (Em/Ev) using biodegradable polymers, specifically Polyactive® 1000PEOT70PBT30 [poly(ethylene-oxide-terephthalate)/poly(butylene-terephthalate); PEOT-PBT] and its polymeric blends with poly-(D, L-lactide-co-glycolide) (PLGA) RG502 and RG503 (PEOT-PBT:PLGA; 65:35). Six different formulations of spherical core-shell microcapsules were successfully developed and characterized. The UA method achieved a significantly higher encapsulation efficiency (69.7-80.25%) than Em/Ev (17.3-23.0%). Mean particle size, strongly determined by the microencapsulation method and to a lesser extent by polymeric composition, ranged from 26.6 to 49.9 µm for UA and 1.5-2.1 µm for Em/Ev. All formulations demonstrated sustained INF release in vitro for up to 24 days, with release rates modulated by polymeric composition and microencapsulation technique. Both methods preserved INF biological activity, with microencapsulated INF showing higher efficacy than commercial formulations at comparable doses regarding bioactive tumor necrosis factor-alpha (TNF-α) neutralization according to WEHI-13VAR bioassay. Microparticles' biocompatibility and extensive internalization by THP-1-derived macrophages was demonstrated. Furthermore, high in vitro anti-inflammatory activity was achieved after treatment of THP-1 cells with INF-loaded microcapsules, significatively reducing in vitro production of TNF-α and interleucine-6 (Il-6).

An Update on Strategies to Deliver Protein and Peptide Drugs to the Eye

In the past few decades, advancements in protein engineering, biotechnology, and structural biochemistry have resulted in the discovery of various techniques that enhanced the production yield of proteins, targetability, circulating half-life, product purity, and functionality of proteins and peptides. As a result, the utilization of proteins and peptides has increased in the treatment of many conditions, including ocular diseases. Ocular delivery of large molecules poses several challenges due to their high molecular weight, hydrophilicity, unstable nature, and poor permeation through cellular and enzymatic barriers. The use of novel strategies for delivering protein and peptides such as glycoengineering, PEGylation, Fc-fusion, chitosan nanoparticles, and liposomes have improved the efficacy, safety, and stability, which consequently expanded the therapeutic potential of proteins. This review article highlights various proteins and peptides that are useful in ocular disorders, challenges in their delivery to the eye, and strategies to enhance ocular bioavailability using novel delivery approaches. In addition, a few futuristic approaches that will assist in the ocular delivery of proteins and peptides were also discussed.

Molecularly Imprinted Nanomedicine for Anti-angiogenic Cancer Therapy via Blocking Vascular Endothelial Growth Factor Signaling

The VEGF-VEGFR2 (VEGF = vascular endothelial growth factor) signaling has been a promising target in cancer therapy. However, because conventional anti-angiogenic therapeutics suffer from drawbacks, particularly severe side effects, novel anti-angiogenic strategies are much needed. Herein, we report the rational engineering of VEGF-targeted molecularly imprinted polymer nanoparticles (nanoMIP) for anti-angiogenic cancer therapy. The anti-VEGF nanomedicine was prepared via a state-of-the-art molecular imprinting approach using the N-terminal epitope of VEGF as the template. The nanoMIP could target the two major pro-angiogenic isoforms (VEGF165 and VEGF121) with high affinity and thereby effectively block the VEGF-VEGFR2 signaling, yielding a potent anti-angiogenic effect of "killing two birds with one stone". In vivo experiments demonstrated that the anti-VEGF nanoMIP effectively suppressed tumor growth via anti-angiogenesis in a xenograft model of human colon carcinoma without apparent side effects. Thus, this study not only proposes an unprecedented anti-angiogenic strategy for cancer therapy but also provides a new paradigm for the rational development of MIPs-based "drug-free" nanomedicines.

Biofunctionalization of 3D printed collagen with bevacizumab-loaded microparticles targeting pathological angiogenesis

Pathological angiogenesis is a crucial attribute of several chronic diseases such as cancer, age-related macular degeneration, and osteoarthritis (OA). In the case of OA, pathological angiogenesis mediated by the vascular endothelial growth factor (VEGF), among other factors, contributes to cartilage degeneration and to implants rejection. In line with this, the use of the anti-VEGF bevacizumab (BVZ) has been shown to prevent OA progression and support cartilage regeneration. The aim of this work was to functionalize a medical grade collagen with poly (lactic-co-glycolic acid) (PLGA) microparticles containing BVZ via three-dimensional (3D) printing to target pathological angiogenesis. First, the effect of several formulation parameters on the encapsulation and release of BVZ from PLGA microparticles was studied. Then, the anti-angiogenic activity of released BVZ was tested in a 3D cell model. The 3D printability of the microparticle-loaded collagen ink was tested by evaluating the shape fidelity of 3D printed structures. Results showed that the release and the encapsulation efficiency of BVZ could be tuned as a function of several formulation parameters. In addition, the released BVZ was observed to reduce vascularization by human umbilical vein endothelial cells. Finally, the collagen ink with embedded BVZ microparticles was successfully printed, leading to shape-stable meniscus-, nose- and auricle-like structures. Taken altogether, we defined the conditions for the successful combination of BVZ-loaded microparticles with the 3D printing of a medical grade collagen to target pathological angiogenesis.

Lecithin/chitosan nanoparticle drug carrier improves anti-tumor efficacy of Monascus pigment rubropunctatin

Rubropunctatin, a metabolite isolated from the fungi of the genus Monascus, is a natural lead compound applied for the suppression of tumors with good anti-cancer activity. However, its poor aqueous solubility has limited its further clinical development and utilization. Lecithin and chitosan are excellently biocompatible and biodegradable natural materials, which have been approved by the FDA as drug carrier. Here, we report for the first time the construction of a lecithin/chitosan nanoparticle drug carrier of the Monascus pigment rubropunctatin by electrostatic self-assembly between lecithin and chitosan. The nanoparticles are near-spherical with a size 110-120 nm. They are soluble in water and possess excellent homogenization capacity and dispersibility. Our in vitro drug release assay showed a sustained release of rubropunctatin. CCK-8 assays revealed that lecithin/chitosan nanoparticles loaded with rubropunctatin (RCP-NPs) had significantly enhanced cytotoxicity against mouse mammary cancer 4T1 cells. The flow cytometry results revealed that RCP-NPs significantly boosted cellular uptake and apoptosis. The tumor-bearing mice models we developed indicated that RCP-NPs effectively inhibited tumor growth. Our present findings suggest that lecithin/chitosan nanoparticle drug carriers improve the anti-tumor effect of the Monascus pigment rubropunctatin.

Fabrication of a curcumin encapsulated bioengineered nano-cocktail formulation for stimuli-responsive targeted therapeutic delivery to enhance anti-inflammatory, anti-oxidant, and anti-bacterial properties in sepsis management

This study aimed to fabricate an eco-friendly functionalized chitosan (CS) nanocarrier to establish a pH-responsive drug delivery system for the treatment of sepsis. Curcumin (Cur) and cerium oxide (CeO₂) were loaded onto an octenylsuccinic anhydride (OSA)-functionalized CS nanoformulation (Cur@Ce/OCS) to achieve an effective nanocarrier (NC) for sepsis treatment. The physicochemical characteristics of the developed nanocarriers were determined using various characterization techniques. The developed CeO₂-OCS nanoformulation has been showed effective anti-bacterial activity (∼97%) against G⁺ and G^- bacterial pathogens, and also have improved drug loading (94% ± 2), and encapsulation efficiency (89.8% ± 1.5), with uniform spherical particles having an average diameter of between 100 and 150 nm. The in vivo experimental results establish that Cur-loaded Ce/OCS NPs could have enhanced therapeutic potential against lung infection model by reducing bacterial burden and extensively decreasing inflammatory responses in sepsis model. Additionally, we determined the in vivo biosafety of the nanoformulations by histological observation of different mouse organs (heart, liver, spleen, and kidney), and observed no signs of toxicity in the treatment groups. The findings of this study clearly demonstrate the therapeutic potential of pH-sensitive nanoplatforms in the management of infectious sepsis.

Overcoming Treatment Challenges in Posterior Segment Diseases with Biodegradable Nano-Based Drug Delivery Systems

Posterior segment eye diseases present a challenge in treatment due to the complex structures in the eye that serve as robust static and dynamic barriers, limiting the penetration, residence time, and bioavailability of topical and intraocular medications. This hinders effective treatment and requires frequent dosing, such as the regular use of eye drops or visits to the ophthalmologist for intravitreal injections, to manage the disease. Moreover, the drugs must be biodegradable to minimize toxicity and adverse reactions, as well as small enough to not affect the visual axis. The development of biodegradable nano-based drug delivery systems (DDSs) can be the solution to these challenges. First, they can stay in ocular tissues for longer periods of time, reducing the frequency of drug administration. Second, they can pass through ocular barriers, offering higher bioavailability to targeted tissues that are otherwise inaccessible. Third, they can be made up of polymers that are biodegradable and nanosized. Hence, therapeutic innovations in biodegradable nanosized DDS have been widely explored for ophthalmic drug delivery applications. In this review, we will present a concise overview of DDSs utilized in the treatment of ocular diseases. We will then examine the current therapeutic challenges faced in the management of posterior segment diseases and explore how various types of biodegradable nanocarriers can enhance our therapeutic arsenal. A literature review of the pre-clinical and clinical studies published between 2017 and 2023 was conducted. Through the advances in biodegradable materials, combined with a better understanding of ocular pharmacology, the nano-based DDSs have rapidly evolved, showing great promise to overcome challenges currently encountered by clinicians.

Anticancer Drugs: Recent Strategies to Improve Stability Profile, Pharmacokinetic and Pharmacodynamic Properties

In past decades, anticancer research has led to remarkable results despite many of the approved drugs still being characterized by high systemic toxicity mainly due to the lack of tumor selectivity and present pharmacokinetic drawbacks, including low water solubility, that negatively affect the drug circulation time and bioavailability. The stability studies, performed in mild conditions during their development or under stressing exposure to high temperature, hydrolytic medium or light source, have demonstrated the sensitivity of anticancer drugs to many parameters. For this reason, the formation of degradation products is assessed both in pharmaceutical formulations and in the environment as hospital waste. To date, numerous formulations have been developed for achieving tissue-specific drug targeting and reducing toxic side effects, as well as for improving drug stability. The development of prodrugs represents a promising strategy in targeted cancer therapy for improving the selectivity, efficacy and stability of active compounds. Recent studies show that the incorporation of anticancer drugs into vesicular systems, such as polymeric micelles or cyclodextrins, or the use of nanocarriers containing chemotherapeutics that conjugate to monoclonal antibodies can improve solubility, pharmacokinetics, cellular absorption and stability. In this study, we summarize the latest advances in knowledge regarding the development of effective highly stable anticancer drugs formulated as stable prodrugs or entrapped in nanosystems.

Antibody-Incorporated Nanomedicines for Cancer Therapy

Antibody-based cancer therapy, one of the most significant therapeutic strategies, has achieved considerable success and progress over the past decades. Nevertheless, obstacles including limited tumor penetration, short circulation half-lives, undesired immunogenicity, and off-target side effects remain to be overcome for the antibody-based cancer treatment. Owing to the rapid development of nanotechnology, antibody-containing nanomedicines that have been extensively explored to overcome these obstacles have already demonstrated enhanced anticancer efficacy and clinical translation potential. This review intends to offer an overview of the advancements of antibody-incorporated nanoparticulate systems in cancer treatment, together with the nontrivial challenges faced by these next-generation nanomedicines. Diverse strategies of antibody immobilization, formats of antibodies, types of cancer-associated antigens, and anticancer mechanisms of antibody-containing nanomedicines are provided and discussed in this review, with an emphasis on the latest applications. The current limitations and future research directions on antibody-containing nanomedicines are also discussed from different perspectives to provide new insights into the construction of anticancer nanomedicines.

Enhanced Anticancer Activity of Hymenocardia acida Stem Bark Extract Loaded into PLGA Nanoparticles

Hymenocardia acida (H. acida) is an African well-known shrub recognized for numerous medicinal properties, including its cancer management potential. The advent of nanotechnology in delivering bioactive medicinal plant extract with poor solubility has improved the drug delivery system, for a better therapeutic value of several drugs from natural origins. This study aimed to evaluate the anticancer properties of H. acida using human lung (H460), breast (MCF-7), and colon (HCT 116) cancer cell lines as well as the production, characterization, and cytotoxicity study of H. acida loaded into PLGA nanoparticles. Benchtop models of Saccharomyces cerevisiae and Raniceps ranninus were used for preliminary toxicity evaluation. Notable cytotoxic activity in benchtop models and human cancer cell lines was observed for H. acida crude extract. The PLGA nanoparticles loading H. acida had a size of about 200 nm and an association efficiency of above 60%, making them suitable to be delivered by different routes. The outcomes from this research showed that H. acida has anticancer activity as claimed from an ethnomedical point of view; however, a loss in activity was noted upon encapsulation, due to the sustained release of the drug.

Intratumoral VEGF nanotrapper reduces gliobastoma vascularization and tumor cell mass

Glioblastoma multiforme (GBM) is the most aggressive and invasive malignant brain cancer. GBM is characterized by a dramatic metabolic imbalance leading to increased secretion of the pro-angiogenic factor VEGF and subsequent abnormal tumor vascularization. In 2009, FDA approved the intravenous administration of bevacizumab, an anti-VEGF monoclonal antibody, as a therapeutic agent for patients with GBM. However, the number of systemic side effects and reduced accessibility of bevacizumab to the central nervous system and consequently to the GBM tumor mass limited its effectiveness in improving patient survival. In this study, we combined experimental and computational modelling to quantitatively characterize the dynamics of VEGF secretion and turnover in GBM and in normal brain cells and simultaneous monitoring of vessel growth. We showed that sequestration of VEGF inside GBM cells, can be used as a novel target for improved bevacizumab-based therapy. We have engineered the VEGF nanotrapper, a cargo system that allows cellular uptake of bevacizumab and inhibits VEGF secretion required for angiogenesis activation and development. Here, we show the therapeutic efficacy of this nanocargo in reducing vascularization and tumor cell mass of GBM in vitro and in vivo cancer models.

Key Points in Remote-Controlled Drug Delivery: From the Carrier Design to Clinical Trials

The increased research activity aiming at improved delivery of pharmaceutical molecules indicates the expansion of the field. An efficient therapeutic delivery approach is based on the optimal choice of drug-carrying vehicle, successful targeting, and payload release enabling the site-specific accumulation of the therapeutic molecules. However, designing the formulation endowed with the targeting properties in vitro does not guarantee its selective delivery in vivo. The various biological barriers that the carrier encounters upon intravascular administration should be adequately addressed in its overall design to reduce the off-target effects and unwanted toxicity in vivo and thereby enhance the therapeutic efficacy of the payload. Here, we discuss the main parameters of remote-controlled drug delivery systems: (i) key principles of the carrier selection; (ii) the most significant physiological barriers and limitations associated with the drug delivery; (iii) major concepts for its targeting and cargo release stimulation by external stimuli in vivo. The clinical translation for drug delivery systems is also described along with the main challenges, key parameters, and examples of successfully translated drug delivery platforms. The essential steps on the way from drug delivery system design to clinical trials are summarized, arranged, and discussed.

Organic Nanocarriers for Bevacizumab Delivery: An Overview of Development, Characterization and Applications

Bevacizumab (BCZ) is a recombinant humanized monoclonal antibody against the vascular endothelial growth factor, which is involved in the angiogenesis process. Pathologic angiogenesis is observed in several diseases including ophthalmic disorders and cancer. The multiple administrations of BCZ can cause adverse effects. In this way, the development of controlled release systems for BCZ delivery can promote the modification of drug pharmacokinetics and, consequently, decrease the dose, toxicity, and cost due to improved efficacy. This review highlights BCZ formulated in organic nanoparticles providing an overview of the physicochemical characterization and in vitro and in vivo biological evaluations. Moreover, the main advantages and limitations of the different approaches are discussed. Despite difficulties in working with antibodies, those nanocarriers provided advantages in BCZ protection against degradation guaranteeing bioactivity maintenance.

Biological drug therapy for ocular angiogenesis: Anti-VEGF agents and novel strategies based on nanotechnology

Currently, biological drug therapy for ocular angiogenesis treatment is based on the administration of anti‐VEGF agents via intravitreal route. The molecules approved with this purpose for ocular use include pegaptanib, ranibizumab, and aflibercept, whereas bevacizumab is commonly off‐label used in the clinical practice. The schedule dosage involves repeated intravitreal injections of anti‐VEGF agents to achieve and maintain effective concentrations in retina and choroids, which are administrated as solutions form. In this review article, we describe the features of different anti‐VEGF agents, major challenges for their ocular delivery and the nanoparticles in development as delivery system of them. In this way, several polymeric and lipid nanoparticles are explored to load anti‐VEGF agents with the aim of achieving sustained drug release and thus, minimize the number of intravitreal injections required. The main challenges were focused in the loading the molecules that maintain their bioactivity after their release from nanoparticulate system, followed the evaluation of them through studies of formulation stability, pharmacokinetic, and efficacy in in vitro and in vivo models. The analysis was based on the information published in peer‐reviewed published papers relevant to anti‐VEGF treatments and nanoparticles developed as ocular anti‐VEGF delivery system.

Engineering Nanoparticles toward the Modulation of Emerging Cancer Immunotherapy

Cancer immunotherapy is a new therapeutic strategy to fight cancer by activating the patients' own immune system. At present, immunotherapy approaches such as cancer vaccines, immune checkpoint blockade (ICB), adoptive cell transfer (ACT), monoclonal antibodies (mAbs) therapy, and cytokines therapy have therapeutic potential in preclinical and clinical applications. However, the intrinsic limitations of conventional immunotherapy are difficulty of precise dosage control, insufficient enrichment in tumor tissues, partial immune response silencing or hyperactivity, and high cost. Engineering nanoparticles (NPs) have been emerging as a promising multifunctional platform to enhance conventional immunotherapy due to their intrinsic immunogenicity, convenient delivery function, controlled surface chemistry activity, multifunctional modifying potential, and intelligent targeting. This review presents the recent progress reflected by engineering NPs, including the diversified selection of functionalized NPs, the superiority of engineering NPs for enhancing conventional immunotherapy, and NP-mediated multiscale strategies for synergistic therapy consisting of compositions and their mechanism. Finally, the perspective on multifunctional NP-based cancer immunotherapy for boosting immunomodulation is discussed, which reveals the expanding landscape of engineering NPs in clinical translation.

Electrospinning nanofiber technology: a multifaceted paradigm in biomedical applications

This review focuses on the process of preparation of nanofibers via Es, the design and setup of the instrument, critical parameter optimization, preferable polymers, solvents, characterization techniques, and recent development and biomedical applications of nanofibers.

Chitosan-Polycaprolactone Core-Shell Microparticles for Sustained Delivery of Bevacizumab

The current therapy for treating neovascular age-related macular degeneration requires monthly intravitreal injection of angiogenesis inhibitors such as bevacizumab or ranibizumab via a 31-gauge needle to inhibit choroidal neovascularization. However, repeated intravitreal injections are associated with poor patient compliance and potential side effects. Microparticle-based injectable devices have shown great promise to address this issue by sustained delivery of protein therapeutics, but critical barriers remain, including limited loading capacity and steady long-term release without compromising the anti-angiogenic activity of drugs. Addressing these challenges, we developed a unique method for synthesizing biodegradable polymer-based core-shell microparticles with sizes around 10 μm, high physical integrity, and uniform size. Subsequent electrostatic and physical interactions to control protein diffusion were designed for the core-shell microparticles to effectively increase the capacity of drug loading to 25%, reduce burst release by almost 30%, and extend the period of drug release from 3 to 6 months. Remarkably, the microparticles enabled a longer-term drug administration and maintained high drug potency up to 6 months in vitro, representing significant advancement compared to conventional microparticle-based delivery platforms or currently commercialized devices. Additionally, the microparticles presented minimal toxicity to human retinal cells in vitro with over 90% cell viability, and they also exhibited good injection feasibility through 31-gauge needles in an ex vivo porcine eye model. These results warrant further studies to evaluate the clinical potential for treating posterior ophthalmic diseases as well as other conditions or injuries requiring long-term local drug administration.

Effective intracellular delivery of bevacizumab via PEGylated polymeric nanoparticles targeting the CD44v6 receptor in colon cancer cells

Colorectal cancer (CRC) is one of the most common and deadly cancers in the world, mainly due to its metastatic and metabolic ability. The CD44 receptor isoform containing exon 6 (CD44v6) is a transmembrane protein that plays an important role in the establishment of tumors and metastasis, which make this molecule a potential target for therapy and diagnosis of tumors. Aiming at a targeted therapy, the anti-VEGF monoclonal antibody (mAb) bevacizumab was loaded into poly(lactic-co-glycolic acid)-polyethylene glycol (PLGA-PEG) nanoparticles (NPs) functionalized with an antibody fragment (Fab) specific for CD44v6-expressing human cancer cells. The sizes of NPs were in the range of 150-250 nm and they had a negative charge between -5 and -10 mV, with an association efficiency (AE) of bevacizumab of 86%. v6 Fab-PLGA-PEG NPs containing bevacizumab specifically bonded to the CD44v6 cell surface receptor and exhibited higher internalization into CD44v6+ epithelial cells than bare and (-) Fab-PLGA-PEG NPs. To understand the biological effect of NP targeting, the intracellular levels of bevacizumab and VEGF were evaluated after the incubation of targeted and untargeted NPs. The intracellular levels of bevacizumab were significantly higher in cells incubated with v6 Fab-PLGA-PEG NPs and these NPs resulted in a significant decrease in the intracellular VEGF compared to untargeted NPs and free bevacizumab. PLGA-PEG NPs, surface-functionalized with a v6-specific Fab, have the potential to intracellularly deliver bevacizumab into CD44v6 expressing cancer cells.

Anti-vascular nano agents: a promising approach for cancer treatment

Anti-vascular agents (AVAs) are a class of promising therapeutic agents with tumor vasculature targeting properties, which can be divided into two types: anti-angiogenic agents (AAAs, inhibit angiogenesis factors) and vascular disrupting agents (VDAs, disrupt established tumor vasculature). AVAs exhibit an enhanced anti-cancer effect by cutting off the oxygen and nutrition supplement channels of tumors. However, the intrinsic drawbacks, such as poor hydrophilicity, undesirable membrane permeability and inferior tumor targeting ability, discount their anti-vascular efficacy. Fortunately, the development of nanotechnology has brought an opportunity for efficient delivery of AVAs to tumour sites with great therapeutic efficacy. The works summarized in this review will provide an understanding of recent advances of anti-vascular nano agents (AVNAs) with a goal to define the mechanism of anti-vascular-based cancer therapy and discuss the challenges and opportunities of AVNAs for clinical translation.

Multifunctional nanomedicines for targeting epidermal growth factor receptor in colorectal cancer

Systemic administration of chemotherapeutics by nanocarriers (NCs) functionalized with targeting agents provides a localized accumulation of drugs in the target tissues and cells. Advanced nanoscaled medicaments can enter into the tumor microenvironment (TME) and overcome the uniquely dysregulated biological settings of TME, including highly pressurized tumor interstitial fluid in an acidic milieu. Such multimodal nanomedicines seem to be one of the most effective treatment modalities against solid tumors such as colorectal cancer (CRC). To progress and invade, cancer cells overexpress various oncogenes and molecular markers such as epidermal growth factor receptors (EGFRs), which can be exploited for targeted delivery of nanoscaled drug delivery systems (DDSs). In fact, to develop effective personalized multimodal nanomedicines, the type of solid tumor and status of the disease in each patient should be taken into consideration. While the development of such multimodal-targeted nanomedicines is largely dependent on the expression level of oncomarkers, the type of NCs and homing/imaging agents play key roles in terms of their efficient applications. In this review, we provide deep insights into the development of EGFR-targeting nanomedicines and discuss various types of nanoscale DDSs (e.g., organic and inorganic nanoparticles) for targeting of the EGFR-positive solid tumors such as CRC.

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.

Lab-On-A-Chip for the Development of Pro-/Anti-Angiogenic Nanomedicines to Treat Brain Diseases

There is a huge demand for pro-/anti-angiogenic nanomedicines to treat conditions such as ischemic strokes, brain tumors, and neurodegenerative diseases such as Alzheimer’s and Parkinson’s. Nanomedicines are therapeutic particles in the size range of 10–1000 nm, where the drug is encapsulated into nano-capsules or adsorbed onto nano-scaffolds. They have good blood–brain barrier permeability, stability and shelf life, and able to rapidly target different sites in the brain. However, the relationship between the nanomedicines’ physical and chemical properties and its ability to travel across the brain remains incompletely understood. The main challenge is the lack of a reliable drug testing model for brain angiogenesis. Recently, microfluidic platforms (known as “lab-on-a-chip” or LOCs) have been developed to mimic the brain micro-vasculature related events, such as vasculogenesis, angiogenesis, inflammation, etc. The LOCs are able to closely replicate the dynamic conditions of the human brain and could be reliable platforms for drug screening applications. There are still many technical difficulties in establishing uniform and reproducible conditions, mainly due to the extreme complexity of the human brain. In this paper, we review the prospective of LOCs in the development of nanomedicines for brain angiogenesis–related conditions.

Enhanced anti-angiogenic effects of bevacizumab in glioblastoma treatment upon intranasal administration in polymeric nanoparticles

Glioblastoma multiforme (GBM) is one of the most aggressive cancers, where the aggressiveness of tumor has been associated to its high vascularization rate. Bevacizumab (Avastin®), an anti-angiogenic monoclonal antibody, has been used to decrease the angiogenic profile. To circumvent the blood-brain barrier (BBB) and decrease off-target organ toxicity, bevacizumab-loaded poly(D,L-lactic-co-glycolic acid) nanoparticles (PLGA NP) were developed and intranasally administrated in CD-1 mice to study their pharmacokinetic and pharmacodynamic profile. After 7 days of administration, PLGA NP showed a higher brain bioavailability of bevacizumab when compared to intranasally administrated free bevacizumab. On the other hand, bevacizumab-loaded PLGA NP were able to increase the penetration (higher Cmáx) and the residence time of bevacizumab into the brain (higher Clast). Furthermore, PLGA NP formulation totally prevented bevacizumab systemic exposure. The efficacy of this nanosystem was next evaluated in a validated orthotopic GBM nude mice model, studying the tumor growth over time by bioluminescence and the anti-angiogenic effects. After 14 days, bevacizumab-loaded PLGA NP demonstrated a reduction in the tumor growth accompanied by a higher anti-angiogenic effect compared to the free bevacizumab. These results can be explained by the fact that bevacizumab was found in the brain just for bevacizumab-loaded PLGA NP group, after 14 days of formulation administration. Therefore, we believe that our strategy would be an efficient alternative to improve GBM treatment with high impact for patient life quality and survival.

'Dendrimer-Cationized-Albumin' encrusted polymeric nanoparticle improves BBB penetration and anticancer activity of doxorubicin

Glioblastoma is one of the most rapaciously growing cancer within the brain with an average lifespan of 12-15 months (5-year survival <3-4%). Doxorubicin (DOX) is clinically utilized as a first line drug in the treatment of Glioblastoma, however, its restricted entry into the brain via the blood-brain barrier (BBB), limited blood-tumor barrier (BTB) permeability, hemotoxicity, short mean half-life of 1-3 hr as well as rapid body clearance results in tremendously diminished bioactivity in glioblastoma. Dendrimer-Cationized-Albumin (dCatAlb) was synthesized following the carboxyl activation technique and the synthesized biopolymer was characterized by FTIR, MALDI-TOF and zeta potential. The prepared dCatAlb was encrusted on DOX-loaded PLGA nanoparticle core to develop a novel hybrid DOX nanoformulation (dCatAlb-pDNP; particle size: 156 ± 10.85 nm; ƺ: -10.0 ± 2.1 mV surface charge). The formulated dCatAlb-pDNP showed a unique pH-dependent DOX release profile, diminished hemolytic toxicity, higher drug uptake (<0.001) and cytotoxicity in U87MG glioblastoma cells, increase levels of caspase-3 gene in U87MG cells (approximately 5.35-fold higher) inferred that anticancer activity is primarily taking place through caspase-mediated apoptosis mechanism. The developed novel DOX nanoformulation also showed superior trans-epithelial permeation transport across monolayer bEnd.3 cells as well as notable biocompatibility and stability. The dCatAlb-pDNP showed enhanced BBB permeation efficacy as confirmed permeation assay in bEnd.3 cell-based model. The long-term formulation stability of developed nanoformulations was studied by storing them at 5 ± 2 °C and 30 ± 2 °C/60 ± 5% Relative Humidity (% RH) in the stability chamber for a period of 60 days (ICHQ1A (R2)). The outcomes of this investigation evidently indicate that dCatAlb-pDNP offers superior anticancer activity of DOX in glioblastoma cells while significantly improving its BBB permeation. The developed formulation is a biocompatible, safer and commercially viable approach to delivering DOX selectively in sustained manner glioblastoma while countering its hemolytic toxic effect, which is a major ongoing issue with conventional DOX injectable available in the market today.