The Smart Drug Delivery System and Its Clinical Potential

Cyclodextrin-Based Magnetic Nanoparticles for Cancer Therapy

Polydopamine (PDA)-coated magnetic nanoparticles functionalized with mono-6-thio-β-cyclodextrin (SH-βCD) were obtained and characterized by transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), Nuclear and Magnetic Resonance Imaging (NMR and MRI), and doxorubicin (DOXO)-loading experiments. The liver cancer cellular internalization of DOXO-loaded nanoparticles was investigated by confocal imaging microscopy. Synthesized nanomaterials bearing a chemotherapeutic drug and a layer of polydopamine capable of absorbing near-infrared light show high performance in the combined chemo- and photothermal therapy (CT-PTT) of liver cancer due to the synergistic effect of both modalities as demonstrated in vitro. Moreover, our material exhibits improved T₂ contrast properties, which have been verified using Carr-Purcell-Meiboom-Gill pulse sequence and MRI Spin-Echo imaging of the nanoparticles dispersed in the agarose gel phantoms. Therefore, the presented results cast new light on the preparation of polydopamine-based magnetic theranostic nanomaterials, as well as on the proper methodology for investigation of magnetic nanoparticles in high field MRI experiments. The prepared material is a robust theranostic nanoasystem with great potential in nanomedicine.

Stimuli-responsive nanocarriers for delivery of bone therapeutics - Barriers and progresses

The development of stimuli-responsive nanomedicines with tunable cargo release is gathering an increased applicability in bone regeneration and precision biomedicine. Yet, the formulation of nanocarriers that explore skeletal-specific stimuli remains remarkably challenging to materialize due to several endogenous and disease-specific barriers that must be considered during particle design stages. Such anatomo-physiological constrains ultimately hinder nanocarriers bioavailability in target bone tissues and impact the overall therapeutic outcome. This review aims to showcase and critically discuss the hurdles encountered upon responsive nanocarriers delivery in the context of skeletal diseases or tissue regeneration scenarios. Such focus is complemented with an in-depth and up-to-date analysis of advances in the development of stimuli-responsive, bone-focused delivery systems. In a holistic perspective, a deeper knowledge of human osteology combined with advances in materials functionalization via simple precision-chemistry is envisioned to incite the manufacture of stimuli-triggered nanomedicines with more realistic potential for clinical translation.

Ferritin-based drug delivery systems: Hybrid nanocarriers for vascular immunotargeting

Ferritin subunits of heavy and light polypeptide chains self-assemble into a spherical nanocage that serves as a natural transport vehicle for metals but can include diverse cargoes. Ferritin nanoparticles are characterized by remarkable stability, small and uniform size. Chemical modifications and molecular re-engineering of ferritin yield a versatile platform of nanocarriers capable of delivering a broad range of therapeutic and imaging agents. Targeting moieties conjugated to the ferritin external surface provide multivalent anchoring of biological targets. Here, we highlight some of the current work on ferritin as well as examine potential strategies that could be used to functionalize ferritin via chemical and genetic means to enable its utility in vascular drug delivery.

Nanomedicine: is it lost in translation?

By the end of 2017 more than 200,000 scientific research articles had been published about nanomedicine. Out of this vast number only a few of the reported nanoconstructs reached clinical trials for various applications, including the diagnosis and treatment of several cancers, and the treatment of infections and other non-cancerous diseases. 30 years after the pioneering work in this field of research, the low product yield at the end of research pipeline leads to a question that is asked by many: 'had nanomedicine been lost in translation?' In this review, we will discuss the landscape of nanomedicine regarding cancer treatment and miscellaneous applications as well as some obstacles toward full utilization of this powerful therapeutic tool and suggest a few solutions to improve the current translational value of nanomedicine research.

Advancements and Challenges in Multidomain Multicargo Delivery Vehicles

Reparative and regenerative processes are well-orchestrated temporal and spatial events that are governed by multiple cells, molecules, signaling pathways, and interactions thereof. Yet again, currently available implantable devices fail largely to recapitulate nature's complexity and sophistication in this regard. Herein, success stories and challenges in the field of layer-by-layer, composite, self-assembly, and core-shell technologies are discussed for the development of multidomain/multicargo delivery vehicles.

Intermolecular G-Quadruplex Induces Hyaluronic Acid-DNA Superpolymers Causing Cancer Cell Swelling, Blebbing, and Death

Over the past decade, nanomedicine has gained considerable attraction through its relevance, for example, in "smart" delivery, thus creating platforms for novel treatments. Here, we report a natural polymer-DNA conjugate that undergoes self-assembly in a K⁺-dependent fashion to form a G-quadruplex (GQ) and generate superpolymeric structures. We derivatized a thiolated conjugate of the naturally occurring glycosaminoglycan polymer hyaluronic acid (HASH) with short G-rich DNA (HASH-DNA) that can form an intermolecular noncanonical GQ structure. Gel mobility shift assay and circular dichroism measurements confirmed HASH conjugation to DNA and K⁺-dependent GQ formation, respectively. Transmission electron microscopy and scanning electron microscopy results indicated that the addition of K⁺ to the HASH-DNA conjugate led to the formation of micron-range structures, whereas control samples remained unordered and as a nebulous globular form. Confocal microscopy of a fluorescently labeled form of the superpolymer verified increased cellular uptake. The HASH-DNA conjugates showed toxicity in HeLa cells, whereas a scrambled DNA (Mut) conjugate HASH-Mut showed no cytotoxicity, presumably because of nonformation of the superpolymeric structure. To understand the mechanism of cell death and if the superpolymeric structure is responsible for it, we monitored the cell size and observed an average of 23% increase in size compared to 4.5% in control cells at 4.5 h. We believe that cellular stress is generated presumably by the intracellular assembly of this large superpolymeric nanostructure causing cell blebbing with no exit option. This approach provides a new strategy of cellular delivery of a targeted naturally occurring polymer and a novel way to induce superpolymeric structure formation that acts as a therapeutic.

Progress in internal/external stimuli responsive fluorescent carbon nanoparticles for theranostic and sensing applications

In the past decade, fluorescent carbon nanoparticles (FNPs) prepared from natural resources and biomaterials have been attractive due to their various properties, such as unique optical properties, great biocompatibility, water dispersion, and facile surface functionalization. Depending on the properties of the carbon sources and the subsequent carbonization processes, internal/external stimuli responsive carbon nanoparticles have been generated that are useful for theranostic and sensing applications. In this review, we highlight the recent developments in the use of FNPs in nanomedicine in great detail, particularly for FNPs responding to internal stimuli, including redox, pH, and enzymes, and external stimuli, including temperature, light, and magnetic fields, for drug delivery and sensing applications. Furthermore, we hope to provide insight that could stimulate further research aiming for unparalleled useful applications. As a result, there are many possibilities that can be explored from this smart material.

Radiation-Sensitive Dendrimer-Based Drug Delivery System

Combination of chemotherapy and radiotherapy is used to enhance local drug delivery while reducing off-target tissue effects. Anticancer drug doxorubicin (DOX) is loaded into l-cysteine modified G4.5 dendrimer (GC/DOX) and released at different pH values in the presence and absence of γ-radiation. Presence of γ-radiation significantly improves DOX release from the GC/DOX under acidic pH conditions, suggesting that GC dendrimer is a radiation-sensitive drug delivery system. GC/DOX is further evaluated by determining cytotoxicity in uterine cervical carcinoma HeLa cells. GC/DOX shows high affinity for cancer cells and effective drug release following an external stimulus (radiation exposure), whereas an in vivo zebrafish study confirms that l-cysteine acts as a radiosensitizer. GC/DOX treatment combined with radiotherapy synergistically and successfully inhibits cancer cell growth.

Vibrating droplet generation to assemble zwitterion-coated gold-graphene oxide stealth nanovesicles for effective pancreatic cancer chemo-phototherapy

A vibrating nozzle approach was used to produce uniform (∼2 μm) hybrid droplets containing gold-graphene oxide (Au-GO), doxorubicin (DOX), and zwitterionic chitosan (ZC) for assembly of Au-GO@ZC-DOX stealth nanovesicles (NVs) via a single-pass diffusion drying process without any hydrothermal reactions, separations, or purifications. NVs were prepared with a lateral dimension of ∼53.0 nm, a pH-triggered high DOX release profile, and strong photothermal effects. Macrophage opsonization was prevented, resulting in anti-cancer and anti-migration effects, with high intracellular uptake in PANC-1 and MIA PaCa-2 cells. PANC-1 tumor uptake was greater for NVs having the ZC configuration than that for NVs without the ZC configuration, resulting in better anti-tumor effects with minimal toxicities. The vibrating nozzle approach offers significant potential to assemble multi-componential NVs for more efficient anti-tumor treatment and easy user-defined manufacturing of multifunctional nanomedicines.

Silk nanoparticles: from inert supports to bioactive natural carriers for drug delivery

Silk proteins have been studied and employed for the production of drug delivery (nano)systems. They show excellent biocompatibility, controllable biodegradability and non-immunogenicity and, if needed, their properties can be modulated by blending with other polymers. Silk fibroin (SF), which forms the inner core of silk, is a (bio)material officially recognized by the Food and Drug Administration for human applications. Conversely, the potential of silk sericin (SS), which forms the external shell of silk, could still be considered under evaluation. At the best of our knowledge, nanoparticles based on silk sericin "alone" cannot be produced, due to its physicochemical instability influenced by extreme pH, high water solubility and temperature; for these reasons, it almost always needs to be combined with other polymers for the development of drug delivery systems. In this review, we focused on silk proteins as bioactive natural carriers, since they show not only optimal features as inert excipients, but also remarkable intrinsic biological activities. SF has anti-inflammatory properties, while SS presents antioxidant, anti-tyrosine, anti-aging, anti-elastase and anti-bacterial features. Here, we give an overview on SF or SS silk-based nanosystems, with particular attention on the production techniques.

Targeting LncRNA-MALAT1 suppresses the progression of osteosarcoma by altering the expression and localization of β-catenin

Osteosarcoma (OS), which affects adolescents especially during a growth spurt, has the highest incidence of any primary malignant bone tumour, and a high rate of early metastasis leading to a very poor prognosis. In recent years, non-coding RNAs, especially long non-coding RNAs (lncRNAs) have attracted more and more attention as novel epigenetic regulators in a variety of tumours, including OS. Most recently, metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) was found to play an important role in OS progression by modulating the enhancers of zeste homolog 2 (EZH2). Furthermore, MALAT1 could inhibit the expression of E-cadherin and promote the expression of β-catenin, and this phenomenon might be the outcome of MALAT1-induced EZH2 activation. In this study, we investigated the vital function of MALAT1 in the progression of OS and its potential leading mechanism, altering the expression and localization of β-catenin via epigenetic transcriptional regulation by interacting with EZH2. With the help of MALAT1 silencing using small interfering RNAs (siRNAs), the loss of E-cadherin of MNNG/HOS cells was rescued, and the abnormal expression and localization of β-catenin were corrected at the same time. Overall, our research showed promising potential for new treatment strategies based on epigenetic regulation targeting MALAT1, which will not only coordinate with the patient's immune system, but also eliminate OS in conjunction with chemotherapy.

Stimuli-Responsive Nanomedicines for Overcoming Cancer Multidrug Resistance

Chemotherapy is still a main option for cancer therapy, but its efficacy is often unsatisfying due to multidrug resistance (MDR). The tumor microenvironment is considered a dominant factor causing MDR. Stimuli-responsive nanomedicines exhibit many superiorities for reversal of MDR. As smart systems, stimuli-responsive nanomedicines are desirable for achieving site-specific accumulation and triggered drug release in response to slight changes in physicochemical properties in pathological conditions or to exogenous stimuli. In this review, we highlight the current progress of various nanomedicines with different stimuli-responsive capabilities for overcoming MDR. The materials, design, construction as well as efficacy in overcoming MDR of these nanomedicines are discussed. Eventually, we look forward to forthcoming intelligent nanoparticle systems with new mechanisms to deliver drugs for practical applications in conquering cancer MDR.

Sinapultide-loaded lipid microbubbles and the stabilization effect of sinapultide on the shells of lipid microbubbles

Sinapultide-loaded lipid microbubbles were fabricated for ultrasound imaging, and the stabilization mechanism was investigated by molecular dynamics simulation.

Synthesis and photophysical properties of BODIPY-decorated graphene quantum dot–phthalocyanine conjugates

A BODIPY dye is linked to graphene quantum dots followed by immobilization of a Zn phthalocyanineviaπ–π stacking, resulting in improved triplet and singlet oxygen quantum yields.

131I-Labeled Copper Sulfide-Loaded Microspheres to Treat Hepatic Tumors via Hepatic Artery Embolization

Purpose: Transcatheter hepatic artery embolization therapy is a minimally invasive alternative for treating inoperable liver cancer but recurrence is frequent. Multifunctional agents, however, offer an opportunity for tumor eradication. In this study, we were aim to synthesized poly (lactic-co-glycolic acid) (PLGA) microspheres encapsulating hollow CuS nanoparticles (HCuSNPs) and paclitaxel (PTX) that were then labeled with radioiodine-131 (¹³¹I) to produce ¹³¹I-HCuSNPs-MS-PTX. This compound combines the multi-theranostic properties of chemotherapy, radiotherapy and photothermal therapy. In addition, it can also be imaged with single photon emission computed tomography (SPECT) imaging and photoacoustic imaging. Methods: We investigated the value of therapeutic and imaging of ¹³¹I-HCuSNPs-MS-PTX in rats bearing Walker-256 tumor transplanted in the liver. After the intra-arterial (IA) injection of ¹³¹I-HCuSNPs-MS-PTX, ¹⁸F-Fluorodeoxyglucose (¹⁸F-FDG) micro-positron emission tomography/computed tomography (micro-PET/CT) imaging was used to monitor the therapeutic effect. PET/CT findings were verified by immunohistochemical analysis. SPECT/CT and photoacoustic imaging were performed to demonstrate the distribution of ¹³¹I-HCuSNPs-MS-PTX in vivo. Results: We found that embolization therapy in combination with chemotherapy, radiotherapy and photothermal therapy offered by ¹³¹I-HCuSNPs-MS-PTX completely ablated the transplanted hepatic tumors at a relatively low dose. In comparison, embolization monotherapy or combination with one or two other therapies had less effective anti-tumor efficacy. The combination of SPECT/CT and photoacoustic imaging effectively confirmed microsphere delivery to the targeted tumors in vivo and guided the near-infrared laser irradiation. Conclusion: Our study suggests that there is a clinical theranostic potential for imaging-guided arterial embolization with ¹³¹I-HCuSNPs-MS-PTX for the treatment of liver tumors.

Remote magnetic switch off microgate for nanofluidic drug delivery implants

In numerous pathologies, implantable drug delivery devices provide advantages over conventional oral or parenteral approaches. Based on the site of implantation and release characteristics, implants can afford either systemic delivery or local administration, whereby the drug is delivered at or near the site of intended action. Unfortunately, current implantable drug delivery systems provide limited options for intervention in the case of an adverse reaction to the drug or the need for dosage adjustment. In the event that drug delivery must be terminated, an urgent surgical retrieval may be the only reliable option. This could be a time sensitive and costly effort, requiring access to trained professionals and emergency medical facilities. To address such limitations, here we demonstrate, in vitro and ex vivo, a novel microsystem for the rapid and effective switch off of drug delivery from an implantable nanofluidic system, by applying a safe external electromagnetic field in the FDA approved dose range. This study represents a proof of concept for a technology with potential for broad applicability to reservoir-based delivery implants for both complete interruption or remote titration of drug administration.

Sequential Delivery of Doxorubicin and Zoledronic Acid to Breast Cancer Cells by CB[7]-Modified Iron Oxide Nanoparticles

Drug-loaded magnetic nanoparticles were synthesized and used for the sequential delivery of the antiresorptive agent zoledronic acid (Zol) and the cytotoxic drug doxorubicin (Dox) to breast cancer cells (MCF-7). Zol was attached to bare iron oxide nanoparticles (IONPs) via phosphonate coordination to form Z-NPs. The unbound imidazole of Zol was then used to complex the organic macrocycle CB[7] to obtain CZ-NPs. Dox was complexed to the CZ-NPs to form the fully loaded particles (DCZ-NPs), which were stable in solution at 37 °C and physiological pH (7.4). Fluorescence spectroscopy established that Dox is released in solution from DCZ-NPs suddenly (i) when the particles are subjected to magnetically induced heating to 42 °C at low pH (5.0) and (ii) in the presence of glutathione (GSH). Mass spectrometry indicated that Zol is released slowly in solution at low pH after Dox release. Magnetic measurements with a magnetic reader revealed that DCZ-NPs are internalized preferentially by MCF-7 cells versus nonmalignant cells (HEK293). Zol and Dox acted synergistically when delivered by the particles. DCZ-NPs caused a decrease in the viability of MCF-7 cells that was greater than the net decrease caused when the drugs were added to the cells individually at concentrations equivalent to those delivered by the particles. MCF-7 cells were treated with DCZ-NPs and subjected to an alternating magnetic field (AMF) which, with the nanoparticles present, raised the temperature of the cells and triggered the intracellular release of Dox, as indicated by fluorescence activated cell sorting (FACS). The cytotoxic effects of the DCZ-NPs on MCF-7 cells were enhanced 10-fold by AMF-induced heating. DCZ-NPs were also able to completely inhibit MCF-7 cell adhesion and invasion in vitro, indicating the potential of the particles to act as antimetastatic agents. Together these results demonstrate that DCZ-NPs warrant development as a system for combined chemo- and thermo-therapeutic treatment of cancer.

A nanoliposome-based photoactivable drug delivery system for enhanced cancer therapy and overcoming treatment resistance

Recently, stimuli-responsive drug delivery systems (DDSs) with high spatial/temporal resolution bring many benefits to cancer treatment. However, cancer cells always develop ways to resist and evade treatment, ultimately limit the treatment efficacy of the DDSs. Here, we introduce photo-activated nanoliposomes (PNLs) that impart light-induced cytotoxicity and reversal of drug resistance in synchrony with a photoinitiated and rapid release of antitumor drug. The PNLs consist of a nanoliposome doped with a photosensitizer (hematoporphyrin monomethyl ether [HMME]) in the lipid bilayer and an antitumor drug doxorubicin (DOX) encapsulated inside. PNLs have several distinctive capabilities: 1) carrying high loadings of DOX and HMME and releasing the payloads in a photo-cleavage manner with high spatial/temporal resolution at the site of actions via photocatalysis; 2) reducing drug efflux in MCF-7/multidrug resistance cells via decreasing the level of P-glycoprotein induced by photodynamic therapy (PDT); 3) accumulating in tumor site taking advantage of the enhanced permeability and retention effect; and 4) combining effective chemotherapy and PDT to exert much enhanced anticancer effect and achieving significant tumor regression in a drug-resistant tumor model with little side effects.

Perspective Insights into Disease Progression, Diagnostics, and Therapeutic Approaches in Alzheimer's Disease: A Judicious Update

Alzheimer's disease (AD) is a neurodegenerative disorder characterized by the progressive accumulation of β-amyloid fibrils and abnormal tau proteins in and outside of neurons. Representing a common form of dementia, aggravation of AD with age increases the morbidity rate among the elderly. Although, mutations in the ApoE4 act as potent risk factors for sporadic AD, familial AD arises through malfunctioning of APP, PSEN-1, and−2 genes. AD progresses through accumulation of amyloid plaques (Aβ) and neurofibrillary tangles (NFTs) in brain, which interfere with neuronal communication. Cellular stress that arises through mitochondrial dysfunction, endoplasmic reticulum malfunction, and autophagy contributes significantly to the pathogenesis of AD. With high accuracy in disease diagnostics, Aβ deposition and phosphorylated tau (p-tau) are useful core biomarkers in the cerebrospinal fluid (CSF) of AD patients. Although five drugs are approved for treatment in AD, their failures in achieving complete disease cure has shifted studies toward a series of molecules capable of acting against Aβ and p-tau. Failure of biologics or compounds to cross the blood-brain barrier (BBB) in most cases advocates development of an efficient drug delivery system. Though liposomes and polymeric nanoparticles are widely adopted for drug delivery modules, their use in delivering drugs across the BBB has been overtaken by exosomes, owing to their promising results in reducing disease progression.

Targeting the long noncoding RNA MALAT1 blocks the pro-angiogenic effects of osteosarcoma and suppresses tumour growth

Osteosarcoma (OS), the commonest primary malignant tumour originating from bone, affects a substantial number of people, mostly during adolescent growth, and leads to a very poor prognosis as a result of the high rate of early metastases. Consequently, there is urgent demand for a novel treatment for this disease. There are growing concerns focused on OS-induced pro-angiogenic effects, but to date, the mechanism of OS-induced pro-angiogenesis is still insufficiently well-understood. Long noncoding RNAs (lncRNAs) have attracted increasing interest due to their strong correlation with a variety of diseases and their powerful capacity for epigenetic regulation. Recently, metastasis-associated lung adenocarcinoma transcript 1 (MALAT1), a lncRNA, has been discovered to be closely related to OS progression and hypoxia responses which are associated with angiogenesis. In this study, we confirm that MALAT1 induces pro-angiogenic effects, and demonstrate that the underlying mechanism involves a MALAT1/mechanistic target of rapamycin (mTOR)/hypoxia inducible factor-1α (HIF-1α) loop. With the help of chemically-modified small interfering RNAs targeting MALAT1 (siMALAT1), we confirm that siMALAT could provide a potential strategy to block the abnormally active OS-induced pro-angiogenic effect, and ultimately successfully suppress progression of OS tumours.

Reactive oxygen species-responsive polymeric nanoparticles for alleviating sepsis-induced acute liver injury in mice

Sepsis-associated acute liver injury contributes to the pathogenesis of multiple organ dysfunction syndrome and is associated with increased mortality. Currently, no specific therapeutics for sepsis-associated liver injury are available. With excess levels of reactive oxygen species (ROS) being implicated as key players in sepsis-induced liver injury, we hypothesize that ROS-responsive nanoparticles (NPs) formed via the self-assembly of diblock copolymers of poly(ethylene glycol) (PEG) and poly(propylene sulfide) (PPS) may function as an effective drug delivery system for alleviating sepsis-induced liver injury by preferentially releasing drug molecules at the disease site. However, there are no reports available on the biocompatibility and effect of PEG-b-PPS-NPs in vivo. Herein, this platform was tested for delivering the promising antioxidant therapeutic molecule melatonin (Mel), which currently has limited therapeutic efficacy because of its poor pharmacokinetic properties. The mPEG-b-PPS-NPs efficiently encapsulated Mel using the oil-in-water emulsion technique and provided sustained, on-demand release that was modulated in vitro by the hydrogen peroxide concentration. Animal studies using a mouse model of sepsis-induced acute liver injury revealed that Mel-loaded mPEG-b-PPS-NPs are biocompatible and much more efficacious than an equivalent amount of free drug in attenuating oxidative stress, the inflammatory response, and subsequent liver injury. Accordingly, this work indicates that mPEG-b-PPS-NPs show potential as an ROS-mediated on-demand drug delivery system for improving Mel bioavailability and treating oxidative stress-associated diseases such as sepsis-induced acute liver injury.

Glutathione responsive micelles incorporated with semiconducting polymer dots and doxorubicin for cancer photothermal-chemotherapy

Nanoplatform integrated with photothermal therapy (PTT) and chemotherapy has been recognized a promising agent for enhancing cancer therapeutic outcomes, but still suffer from less controllability for optimizing their synergistic effects. We fabricated glutathione (GSH) responsive micelles incorporated with semiconducting polymer dots and doxorubicin (referred as SPDOX NPs) for combining PTT with chemotherapy to enhance cancer therapeutic efficiency. These micelles, with excellent water dispersibility, comprises of three distinct functional components: (1) the monomethoxy-poly(ethylene glycol)-S-S-hexadecyl (mPEG-S-S-C16), which forms the micelles, can render hydrophobic substances water-soluble and improve the colloidal stability; (2) disulfide linkages can be cleaved in a reductive environment for tumor specific drug release due to the high GSH concentrations of tumor micro-environment; (3) PCPDTBT dots and anti-cancer drug DOX that are loaded inside the hydrophobic core of the micelle can be applied to simultaneously perform PTT and chemotherapy to achieve significantly enhanced tumor killing efficiency both in vitro and in vivo. In summary, our studies demonstrated that our SPDOX NPs with simultaneous photothermal-chemotherapy functions could be a promising platform for a tumor specific responsive drug delivery system.

Personalized Nanomedicine: A Revolution at the Nanoscale

Nanomedicine is an interdisciplinary research field that results from the application of nanotechnology to medicine and has the potential to significantly improve some current treatments. Specifically, in the field of personalized medicine, it is expected to have a great impact in the near future due to its multiple advantages, namely its versatility to adapt a drug to a cohort of patients. In the present review, the properties and requirements of pharmaceutical dosage forms at the nanoscale, so-called nanomedicines, are been highlighted. An overview of the main current nanomedicines in pre-clinical and clinical development is presented, detailing the challenges to the personalization of these therapies. Next, the process of development of novel nanomedicines is described, from their design in research labs to their arrival on the market, including considerations for the design of nanomedicines adapted to the requirements of the market to achieve safe, effective, and quality products. Finally, attention is given to the point of view of the pharmaceutical industry, including regulation issues applied to the specific case of personalized medicine. The authors expect this review to be a useful overview of the current state of the art of nanomedicine research and industrial production, and the future opportunities of personalized medicine in the upcoming years. The authors encourage the development and marketing of novel personalized nanomedicines.

Use of nanoparticles for glioblastoma treatment: a new approach

Glioblastoma (GBM) is a very aggressive CNS tumor with poor prognosis. Current treatment lacks efficacy indicating that new therapeutic approaches are needed. One of these new approaches is based on the use of nanoparticles (NPs) to deliver different cargos (antitumoral drugs or genetic materials) to tumoral cells. This review covers the signaling pathways altered in GBM cells to understand the rationale behind choosing new therapeutic targets and recent advances in the use of different NPs to deliver to GBM cells, both in vitro and in vivo, different therapeutic molecules. A special focus is placed on the effect of NPs on orthotopic brain tumors since this animal model represents the optimal model for translational purposes.

A Eutectic Mixture of Natural Fatty Acids Can Serve as the Gating Material for Near-Infrared-Triggered Drug Release

A smart release system responsive to near-infrared (NIR) light is developed for intracellular drug delivery. The concept is demonstrated by coencapsulating doxorubicin (DOX) (an anticancer drug) and IR780 iodide (IR780) (an NIR-absorbing dye) into nanoparticles made of a eutectic mixture of naturally occurring fatty acids. The eutectic mixture has a well-defined melting point at 39 °C, and can be used as a biocompatible phase-change material for NIR-triggered drug release. The resultant nanoparticles exhibit prominent photothermal effect and quick drug release in response to NIR irradiation. Fluorescence microscopy analysis indicates that the DOX trapped in the nanoparticles can be efficiently released into the cytosol under NIR irradiation, resulting in enhanced anticancer activity. A new platform is thus offered for designing effective intracellular drug-release systems, holding great promise for future cancer therapy.

Chemical Modulation of in Vivo Macrophage Function with Subpopulation-Specific Fluorescent Prodrug Conjugates

Immunomodulatory agents represent one of the most promising strategies for enhancing tissue regeneration without the side effects of traditional drug-based therapies. Tissue repair depends largely on macrophages, making them ideal targets for proregenerative therapies. However, given the multiple roles of macrophages in tissue homeostasis, small molecule drugs must be only active in very specific subpopulations. In this work, we have developed the first prodrug-fluorophore conjugates able to discriminate closely related subpopulations of macrophages (i.e., proinflammatory M1 vs anti-inflammatory M2 macrophages), and employed them to deplete M1 macrophages in vivo without affecting other cell populations. Selective intracellular activation and drug release enabled simultaneous fluorescence cell tracking and ablation of M1 macrophages in vivo, with the concomitant rescue of a proregenerative phenotype. Ex vivo assays in human monocyte-derived macrophages validate the translational potential of this novel platform to develop chemical immunomodulatory agents as targeted therapies for immune-related diseases.

Peptide dendrimers: drug/gene delivery and other approaches

Dendrimers are versatile hyperbranched molecules, which have deserved attention especially for their potential in many applications, including biological. Peptide dendrimers comprise interesting classes of dendrimers, and their use has been emphasized as a drug/bioactive compound delivery system, mostly in the antineoplastic area. The bioactive molecules can be covalently linked or entrapped inside the peptide derivative. Self-assembled nanocarriers are a recent trend in the design of potential delivery systems, and pH-sensitive carriers, one of their methods, have been designed to control their systems. In addition, the use of targeting peptides or other specific groups that direct the drug/bioactive compounds to specific organs is an important trend in the search for better drug delivery systems. Recent examples have been given in the literature, showing that gene delivery as another important peptide dendrimer application. It is worth emphasizing that some peptide dendrimers show activity per se, without bioactive compounds. Immune compounds and vaccines are presented herein, as well as uses of other peptide dendrimers are briefly discussed in this review, which encompasses around 10 years of work.

Carbon nanotubes functionalized with folic acid attached via biomimetic peptide linker

AIM

Anchoring folic acid (FA) with a biomimetic peptidic linker resistant to proteolytic degradation to act as a homing device on functionalized carbon nanotubes.

MATERIALS & METHODS

Ethylenediamine was attached to oxidized multiwalled carbon nanotubes (MWNTs) using 4-(4,6-dimethoxy-[1,3,5]triazin-2-yl)-4-methylmorpholinium tetrafluoroborate. FA was coupled with 6-aminohexanoic acid and derivatives of β-alanine, affording four intermediates, which connected to the MWNTs via peptidic linkers of various lengths.

RESULTS

Biomimetic nanomaterials were produced with FA as a homing molecule. The structure and properties of the nanomaterials were analyzed, confirming the versatility of the peptides used as linkers.

CONCLUSION

Conjugates of FA attached to MWNTs via peptide linkers prepared from β-alanine residues are resistant to proteolytic degradation. Viability in colon cancer cells and normal colonocytes confirmed their lack of cytotoxicity.

Engineering Compartmentalized Biomimetic Micro- and Nanocontainers

Compartmentalization of biological content and function is a key architectural feature in biology, where membrane bound micro- and nanocompartments are used for performing a host of highly specialized and tightly regulated biological functions. The benefit of compartmentalization as a design principle is behind its ubiquity in cells and has led to it being a central engineering theme in construction of artificial cell-like systems. In this review, we discuss the attractions of designing compartmentalized membrane-bound constructs and review a range of biomimetic membrane architectures that span length scales, focusing on lipid-based structures but also addressing polymer-based and hybrid approaches. These include nested vesicles, multicompartment vesicles, large-scale vesicle networks, as well as droplet interface bilayers, and double-emulsion multiphase systems (multisomes). We outline key examples of how such structures have been functionalized with biological and synthetic machinery, for example, to manufacture and deliver drugs and metabolic compounds, to replicate intracellular signaling cascades, and to demonstrate collective behaviors as minimal tissue constructs. Particular emphasis is placed on the applications of these architectures and the state-of-the-art microfluidic engineering required to fabricate, functionalize, and precisely assemble them. Finally, we outline the future directions of these technologies and highlight how they could be applied to engineer the next generation of cell models, therapeutic agents, and microreactors, together with the diverse applications in the emerging field of bottom-up synthetic biology.

Mesenchymal stem/stromal cell extracellular vesicles: From active principle to next generation drug delivery system

It has been demonstrated that the biological effector of mesenchymal stem/stromal cells (MSCs) is their secretome, which is composed of a heterogeneous pool of bioactive molecules, partially enclosed in extracellular vesicles (EVs). Therefore, the MSC secretome (including EVs) has been recently proposed as possible alternative to MSC therapy. The secretome can be considered as a protein-based biotechnological product, it is probably safer compared with living/cycling cells, it presents virtually lower tumorigenic risk, and it can be handled, stored and sterilized as an Active Pharmaceutical/Principle Ingredient (API). EVs retain some structural and technological analogies with synthetic drug delivery systems (DDS), even if their potential clinical application is also limited by the absence of reproducible/scalable isolation methods and Good Manufacturing Practice (GMP)-compliant procedures. Notably, EVs secreted by MSCs preserve some of their parental cell features such as homing, immunomodulatory and regenerative potential. This review focuses on MSCs and their EVs as APIs, as well as DDS, considering their ability to reach inflamed and damaged tissues and to prolong the release of encapsulated drugs. Special attention is devoted to the illustration of innovative therapeutic approaches in which nanomedicine is successfully combined with stem cell therapy, thus creating a novel class of "next generation drug delivery systems."

Engineering exosomes as refined biological nanoplatforms for drug delivery

Exosomes, a subgroup of extracellular vesicles (EVs), have been recognized as important mediators of long distance intercellular communication and are involved in a diverse range of biological processes. Because of their ideal native structure and characteristics, exosomes are promising nanocarriers for clinical use. Exosomes are engineered at the cellular level under natural conditions, but successful exosome modification requires further exploration. The focus of this paper is to summarize passive and active loading approaches, as well as specific exosome modifications and examples of the delivery of therapeutic and imaging molecules. Examples of exosomes derived from a variety of biological origins are also provided. The biocompatible characteristics of exosomes, with suitable modifications, can increase the stability and efficacy of imaging probes and therapeutics while enhancing cellular uptake. Challenges in clinical translation of exosome-based platforms from different cell sources and the advantages of each are also reviewed and discussed.

Enhancing regenerative approaches with nanoparticles

In this review, we discuss recent developments in the field of nanoparticles and their use in tissue regeneration approaches. Owing to their unique chemical properties and flexibility in design, nanoparticles can be used as drug delivery systems, to create novel features within materials or as bioimaging agents, or indeed these properties can be combined to create smart multifunctional structures. This review aims to provide an overview of this research field where the focus will be on nanoparticle-based strategies to stimulate bone regeneration; however, the same principles can be applied for other tissue and organ regeneration strategies. In the first section, nanoparticle-based methods for the delivery of drugs, growth factors and genetic material to promote tissue regeneration are discussed. The second section deals with the addition of nanoparticles to materials to create nanocomposites. Such materials can improve several material properties, including mechanical stability, biocompatibility and biological activity. The third section will deal with the emergence of a relatively new field of research using nanoparticles in advanced cell imaging and stem cell tracking approaches. As the development of nanoparticles continues, incorporation of this technology in the field of regenerative medicine will ultimately lead to new tools that can diagnose, track and stimulate the growth of new tissues and organs.

Biomedical applications of nanotechnology

The ability to investigate substances at the molecular level has boosted the search for materials with outstanding properties for use in medicine. The application of these novel materials has generated the new research field of nanobiotechnology, which plays a central role in disease diagnosis, drug design and delivery, and implants. In this review, we provide an overview of the use of metallic and metal oxide nanoparticles, carbon-nanotubes, liposomes, and nanopatterned flat surfaces for specific biomedical applications. The chemical and physical properties of the surface of these materials allow their use in diagnosis, biosensing and bioimaging devices, drug delivery systems, and bone substitute implants. The toxicology of these particles is also discussed in the light of a new field referred to as nanotoxicology that studies the surface effects emerging from nanostructured materials.

Preparation and in vivo safety evaluations of antileukemic homoharringtonine-loaded PEGylated liposomes

In order to improve the in vivo safety and specific delivery efficiency of the antileukemic homoharringtonine (HHT) at the targets, the long-circulating PEGylated liposomes loaded with HHT (LCLipo-HHT) were prepared. Their physical characteristics, in vitro drug release, in vivo pharmacokinetic properties and elementary toxicity were evaluated. The mean diameter of the prepared LCLipo-HHT is 75.6 ± 3.2 nm and the zeta potential is -16.9 ± 2.5 mV. The entrapment efficiency of HHT in the liposomes is 69.5 ± 1.7%. In pharmacokinetic experiments, an increased plasma concentration as well as blood circulation time was obtained when distearoyl phosphoethanolamine-PEG 2000 lipid was added in the formulation, which results in enhancing drug delivery efficiency. Hemolysis test, vascular irritation test and acute toxicity test were used to demonstrate toxicity of LCLipo-HHT. Compared with clinical HHT injection dosage, LCLipo-HHT indicated no vascular irritation, good hemocompatibility, as well as much better safety. Therefore, the prepared LCLipo-HHT can be used as a promising anticancer formulation for antileukemic therapy in the future.

Presence of an Immune System Increases Anti-Tumor Effect of Ag Nanoparticle Treated Mice

To date, most nanomedical studies rely on the use of immune-deficient mice in which the contribution of the immune system on the applied therapy is ignored. Here, the degradation of silver nanoparticles (Ag NPs) is exploited as a means to treat subcutaneous tumor models in mice. To investigate the impact of the immune system, the same tumor cell type (KLN 205 murine squamous cell carcinoma) is used in a xenograft model in NOD SCIDγ immune-deficient mice and as a syngeneic model in immune-competent DBA/2 mice. The Ag NPs are screened for their cytotoxicity on various cancer cell lines, indicating a concentration-dependent induction of oxidative stress, mitochondrial damage, and autophagy on all cell types tested. At subcytotoxic concentrations, prolonged cellular exposure to the Ag NPs results in toxicity due to NP degradation and the generation of toxic Ag⁺ ions. At subcytotoxic conditions, the NPs are found to cause inflammation in vitro. Similar results are obtained in the immune-competent mouse model, where clear inflammation is observed after treatment of the implanted tumors with Ag NPs. This inflammation leads to an ongoing antitumoral effect, which results in a significantly reduced tumor growth compared to Ag NP-treated tumors in an immune-deficient model.

Paulo T, de França Lopes LG, Sousa EHS. A biphosphinic ruthenium complex with potent anti-bacterial and anti-cancer activity

Photorelease of CO and moderate binding to DNA did not seem to be essential features for potent biological activities.