Enhanced Delivery of Therapeutic siRNA into Glioblastoma Cells Using Dendrimer-Entrapped Gold Nanoparticles Conjugated with β-Cyclodextrin

A recent insight of applications of gold nanoparticles in glioblastoma multiforme therapy

The application of gold nanoparticles (AuNPs) in cancer therapy, particularly targeted therapy of glioblastoma multiforme (GBM), is an up-and-coming field of research that has gained much interest in recent years. GBM is a life-threatening malignant tumour of the brain that currently has a 95 % death rate with an average of 15 months of survival. AuNPs have proven to have wide clinical implications and compelling therapeutic potential in many researches, specifically in GBM treatment. It was found that the reason why AuNPs were highly desired for GBM treatment was due to their unique properties that diversified the applications of AuNPs further to include imaging, diagnosis, and photothermal therapy. These properties include easy synthesis, biocompatibility, and surface functionalization. Various studies also underscored the ability of AuNPs to cross the blood-brain-barrier and selectively target tumour cells while displaying no major safety concerns which resulted in better therapy results. We attempt to bring together some of these studies in this review and provide a comprehensive overview of safety evaluations and current and potential applications of AuNPs in GBM therapy that may result in AuNP-mediated therapy to be the new gold standard for GBM treatment.

Multifunctional Nanocarriers for Alzheimer's Disease: Befriending the Barriers

Neurodegenerative diseases (NDDs) have been increasing in incidence in recent years and are now widespread worldwide. Neuronal death is defined as the progressive loss of neuronal structure or function which is closely associated with NDDs and represents the intrinsic features of such disorders. Amyotrophic lateral sclerosis, frontotemporal dementia, Alzheimer's, Parkinson's, and Huntington's diseases (AD, PD, and HD, respectively) are considered neurodegenerative diseases that affect a large number of people worldwide. Despite the testing of various drugs, there is currently no available therapy that can remedy or effectively slow the progression of these diseases. Nanomedicine has the potential to revolutionize drug delivery for the management of NDDs. The use of nanoparticles (NPs) has recently been developed to improve drug delivery efficiency and is currently subjected to extensive studies. Nanoengineered particles, known as nanodrugs, can cross the blood-brain barrier while also being less invasive compared to the most treatment strategies in use. Polymeric, magnetic, carbonic, and inorganic NPs are examples of NPs that have been developed to improve drug delivery efficiency. Primary research studies using NPs to cure AD are promising, but thorough research is needed to introduce these approaches to clinical use. In the present review, we discussed the role of metal-based NPs, polymeric nanogels, nanocarrier systems such as liposomes, solid lipid NPs, polymeric NPs, exosomes, quantum dots, dendrimers, polymersomes, carbon nanotubes, and nanofibers and surfactant-based systems for the therapy of neurodegenerative diseases. In addition, we highlighted nanoformulations such as N-butyl cyanoacrylate, poly(butyl cyanoacrylate), D-penicillamine, citrate-coated peptide, magnetic iron oxide, chitosan (CS), lipoprotein, ceria, silica, metallic nanoparticles, cholinesterase inhibitors, an acetylcholinesterase inhibitors, metal chelators, anti-amyloid, protein, and peptide-loaded NPs for the treatment of AD.

Harnessing the potential of nanoengineered siRNAs carriers for target responsive glioma therapy: Recent progress and future opportunities

Past scientific testimonials in the field of glioma research, the deadliest tumor among all brain cancer types with the life span of 10-15 months after diagnosis is considered as glioblastoma multiforme (GBM). Even though the availability of treatment options such as chemotherapy, radiotherapy, and surgery, are unable to completely cure GBM due to tumor microenvironment complexity, intrinsic cellular signalling, and genetic mutations which are involved in chemoresistance. The blood-brain barrier is accountable for restricting drugs entry at the tumor location and related biological challenges like endocytic degradation, short systemic circulation, and insufficient cellular penetration lead to tumor aggression and progression. The above stated challenges can be better mitigated by small interfering RNAs (siRNA) by knockdown genes responsible for tumor progression and resistance. However, siRNA encounters with challenges like inefficient cellular transfection, short circulation time, endogenous degradation, and off-target effects. The novel functionalized nanocarrier approach in conjunction with biological and chemical modification offers an intriguing potential to address challenges associated with the naked siRNA and efficiently silence STAT3, coffilin-1, EGFR, VEGF, SMO, MGMT, HAO-1, GPX-4, TfR, LDLR and galectin-1 genes in GBM tumor. This review highlights the nanoengineered siRNA carriers, their recent advancements, future perspectives, and strategies to overcome the systemic siRNA delivery challenges for glioma treatment.

Potential of Nanocarrier-Associated Approaches for Better Therapeutic Intervention in the Management of Glioblastoma

Glioblastoma, commonly known as glioblastoma multiforme (GBM), is one of the deadliest and most invasive types of brain cancer. Two factors account for the majority of the treatment limitations for GBM. First, the presence of the blood-brain barrier (BBB) renders malignancy treatment ineffective, leading to recurrence without full recovery. Second, several adverse effects are associated with the drugs used in conventional GBM treatment. Recent studies have developed nanocarrier systems, such as liposomes, polymeric micelles, dendrimers, nanosuspensions, nanoemulsions, nanostructured lipid carriers, solid lipid nanocarriers, metal particles, and silica nanoparticles, which allow drug-loaded formulations to penetrate the BBB more effectively. This has opened up new possibilities for overcoming therapy issues. Extensive and methodical searches of databases such as PubMed, Science Direct, Google Scholar, and others were conducted to gather relevant literature for this work, using precise keyword combinations such as "GBM," "brain tumor," and "nanocarriers." This review provides deep insights into the administration of drugs using nanocarriers for the management of GBM and explores new advancements in nanotechnology. It also highlights how scientific developments can be explained in connection with hopeful findings about the potential of nanocarriers for the future successful management of GBM.

Recent Breakthroughs in Using Quantum Dots for Cancer Imaging and Drug Delivery Purposes

Cancer is one of the leading causes of death worldwide. Because each person's cancer may be unique, diagnosing and treating cancer is challenging. Advances in nanomedicine have made it possible to detect tumors and quickly investigate tumor cells at a cellular level in contrast to prior diagnostic techniques. Quantum dots (QDs) are functional nanoparticles reported to be useful for diagnosis. QDs are semiconducting tiny nanocrystals, 2-10 nm in diameter, with exceptional and useful optoelectronic properties that can be tailored to sensitively report on their environment. This review highlights these exceptional semiconducting QDs and their properties and synthesis methods when used in cancer diagnostics. The conjugation of reporting or binding molecules to the QD surface is discussed. This review summarizes the most recent advances in using QDs for in vitro imaging, in vivo imaging, and targeted drug delivery platforms in cancer applications.

Research progress of siVEGF complex and their application in antiangiogenic therapy

Vascular endothelial growth factor (VEGF) is an important factor in the development of some diseases such as tumors, ocular neovascular disease and endometriosis. Inhibition of abnormal VEGF expression is one of the most effective means of treating these diseases. The resistance and side effects of currently used VEGF drugs limit their application. Herein, small interfering RNA for VEGF (siVEGF) are developed to inhibit VEGF expression at the genetic level by means of RNA interference. However, as a foreign substance entering the organism, siVEGF is prone to induce an immune response or mismatch, which adversely affects the organism. It is also subjected to enzymatic degradation and cell membrane blockage, which greatly reduces its therapeutic effect. Targeted siVEGF complexes are constructed by nanocarriers to avoid their clearance by the body and precisely target cells, exerting anti-vascular effects for the treatment of relevant diseases. In addition, some multifunctional complexes allow for the combination of siVEGF with other therapeutic tools to improve the treat efficiency of the disease. Therefore, this review describes the construction of the siVEGF complex, its mechanism of action, application in anti-blood therapy, and provides an outlook on its current problems and prospects.

Novel sights on therapeutic, prognostic, and diagnostics aspects of non-coding RNAs in glioblastoma multiforme

Glioblastoma Multiforme (GBM) is the primary brain tumor and accounts for 200,000 deaths each year worldwide. The standard therapy includes surgical resection followed by temozolomide (TMZ)-based chemotherapy and radiotherapy. The survival period of GBM patients is only 12-15 months. Therefore, novel treatment modalities for GBM treatment are urgently needed. Mounting evidence reveals that non-coding RNAs (ncRNAs) were involved in regulating gene expression, the pathophysiology of GBM, and enhancing therapeutic outcomes. The combinatory use of ncRNAs, chemotherapeutic drugs, and tumor suppressor gene expression induction might provide an innovative, alternative therapeutic approach for managing GBM. Studies have highlighted the role of Long non-coding RNAs (lncRNAs) and microRNAs (miRNAs) in prognosis and diagnosis. Dysregulation of ncRNAs is observed in virtually all tumor types, including GBMs. Studies have also indicated the blood-brain barrier (BBB) as a crucial factor that hinders chemotherapy. Although several nanoparticle-mediated drug deliveries were degrading effectively against GBM in vitro conditions. However, the potential to cross the BBB and optimum delivery of oligonucleotide RNA into GBM cells in the brain is currently under intense clinical trials. Despite several advances in molecular pathogenesis, GBM remains resistant to chemo and radiotherapy. Targeted therapies have less clinical benefit due to high genetic heterogeneity and activation of alternative pathways. Thus, identifying GBM-specific prognostic pathways, essential genes, and genomic aberrations provide several potential benefits as subtypes of GBM. Also, these approaches will provide insights into new strategies to overcome the heterogenous nature of GBM, which will eventually lead to successful therapeutic interventions toward precision medicine and precision oncology.

Interplay between Nanoparticles and Phosphorus Dendrimers, and Their Properties

This review presents the state of the art of interactions between two different families of nanoobjects: nanoparticles-mainly metal nanoparticles, and dendrimers-mainly phosphorhydrazone dendrimers (or dendrons). The review firstly presents the encapsulation/protection of existing nanoparticles (organic or metallic) by phosphorus-based dendrimers and dendrons. In the second part, several methods for the synthesis of metal nanoparticles, thanks to the dendrimer that acts as a template, are presented. The properties of the associations between dendrimers and nanoparticles are emphasized throughout the review. These properties mainly concern the elaboration of diverse types of hybrid materials, some of them being used as sensitive chemosensors or biosensors. Several examples concerning catalysis are also given, displaying in particular the efficient recovery and reuse of the catalytic entities.

Recent Advances in the Pharmaceutical and Biomedical Applications of Cyclodextrin-Capped Gold Nanoparticles

The real problem in pharmaceutical preparation is drugs' poor aqueous solubility, low permeability through biological membranes, and short biological t_1/2. Conventional drug delivery systems are not able to overcome these problems. However, cyclodextrins (CDs) and their derivatives can solve these challenges. This article aims to summarize and review the history, properties, and different applications of cyclodextrins, especially the ability of inclusion complex formation. It also refers to the effects of cyclodextrin on drug solubility, bioavailability, and stability. Moreover, it focuses on preparing and applying gold nanoparticles (AuNPs) as novel drug delivery systems. It also studies the uses and effects of cyclodextrins in this field as novel drug carriers and targeting devices. The system formulated from AuNPs linked with CD molecules combines the advantages of both CD and AuNPs. Cyclodextrins benefit in increasing aqueous drug solubility, loading capacity, stability, and size control of gold NPs. Also, AuNPs are applied as diagnostic and therapeutic agents because of their unique chemical properties. Plus, AuNPs possess several advantages such as ease of detection, targeted and selective drug delivery, greater surface area, high loading efficiency, and higher stability than microparticles. In the present article, we tried to present the potential pharmaceutical applications of CD-derived AuNPs in biomedical applications including antibacterial, anticancer, gene-drug delivery, and various targeted drug delivery applications. Also, the article highlighted the role of CDs in the preparation and improvement of catalytic enzymes, the formation of self-assembling molecular print boards, the fabrication of supramolecular functionalized electrodes, and biosensors formation.

A cationic lipid with advanced membrane fusion performance for pDNA and mRNA delivery

The success of mRNA vaccines for COVID-19 prevention raised global awareness of the importance of nucleic acid drugs. The approved systems for nucleic acid delivery were mainly formulations of different lipids, yielding lipid nanoparticles (LNPs) with complex internal structures. Due to the multiple components, the relationship between the structure of each component and the overall biological activity of LNPs is hard to study. However, ionizable lipids have been extensively explored. In contrast to former studies on the optimization of hydrophilic parts in single-component self-assemblies, we report in this study on structural alterations of the hydrophobic segment. We synthesize a library of amphiphilic cationic lipids by varying the lengths (C = 8-18), numbers (N = 2, 4), and unsaturation degrees (Ω = 0, 1) of hydrophobic tails. Notably, all self-assemblies with nucleic acid have significant differences in particle size, stability in serum, membrane fusion, and fluidity. Moreover, the novel mRNA/pDNA formulations are characterized by overall low cytotoxicity, efficient compaction, protection, and release of nucleic acids. We find that the length of hydrophobic tails dominates the formation and stability of the assembly. And at a certain length, the unsaturated hydrophobic tails enhance the membrane fusion and fluidity of assemblies and thus significantly affect the transgene expression, followed by the number of hydrophobic tails.

Multifunctional nanocarriers for delivering siRNA and miRNA in glioblastoma therapy: advances in nanobiotechnology-based cancer therapy

Glioblastoma multiforme (GBM) is one of the most lethal cancer due to poor diagnosis and rapid resistance developed towards the drug. Genes associated to cancer-related overexpression of proteins, enzymes, and receptors can be suppressed using an RNA silencing technique. This assists in obtaining tumour targetability, resulting in less harm caused to the surrounding healthy cells. RNA interference (RNAi) has scientific basis for providing potential therapeutic applications in improving GBM treatment. However, the therapeutic application of RNAi is challenging due to its poor permeability across blood-brain barrier (BBB). Nanobiotechnology has evolved the use of nanocarriers such as liposomes, polymeric nanoparticles, gold nanoparticles, dendrimers, quantum dots and other nanostructures in encasing the RNAi entities like siRNA and miRNA. The review highlights the role of these carriers in encasing siRNA and miRNA and promising therapy in delivering them to the glioma cells.

Polymeric Dendrimers as Nanocarrier Vectors for Neurotheranostics

Dendrimers are polymers with well-defined 3D branched structures that are vastly utilized in various neurotheranostics and biomedical applications, particularly as nanocarrier vectors. Imaging agents can be loaded into dendrimers to improve the accuracy of diagnostic imaging processes. Likewise, combining pharmaceutical agents and anticancer drugs with dendrimers can enhance their solubility, biocompatibility, and efficiency. Practically, by modifying ligands on the surface of dendrimers, effective therapeutic and diagnostic platforms can be constructed and implemented for targeted delivery. Dendrimer-based nanocarriers also show great potential in gene delivery. Since enzymes can degrade genetic materials during their blood circulation, dendrimers exhibit promising packaging and delivery alternatives, particularly for central nervous system (CNS) treatments. The DNA and RNA encapsulated in dendrimers represented by polyamidoamine that are used for targeted brain delivery, via chemical-structural adjustments and appropriate generation, significantly improve the correlation between transfection efficiency and cytotoxicity. This article reports a comprehensive review of dendrimers' structures, synthesis processes, and biological applications. Recent progress in diagnostic imaging processes and therapeutic applications for cancers and other CNS diseases are presented. Potential challenges and future directions in the development of dendrimers, which provide the theoretical basis for their broader applications in healthcare, are also discussed.

Molecular Engines, Therapeutic Targets, and Challenges in Pediatric Brain Tumors: A Special Emphasis on Hydrogen Sulfide and RNA-Based Nano-Delivery

Pediatric primary brain tumors represent a real challenge in the oncology arena. Besides the psychosocial burden, brain tumors are considered one of the most difficult-to-treat malignancies due to their sophisticated cellular and molecular pathophysiology. Notwithstanding the advances in research and the substantial efforts to develop a suitable therapy, a full understanding of the molecular pathways involved in primary brain tumors is still demanded. On the other hand, the physiological nature of the blood-brain barrier (BBB) limits the efficiency of many available treatments, including molecular therapeutic approaches. Hydrogen Sulfide (H2S), as a member of the gasotransmitters family, and its synthesizing machinery have represented promising molecular targets for plentiful cancer types. However, its role in primary brain tumors, generally, and pediatric types, particularly, is barely investigated. In this review, the authors shed the light on the novel role of hydrogen sulfide (H2S) as a prominent player in pediatric brain tumor pathophysiology and its potential as a therapeutic avenue for brain tumors. In addition, the review also focuses on the challenges and opportunities of several molecular targeting approaches and proposes promising brain-delivery strategies for the sake of achieving better therapeutic results for brain tumor patients.

A Review on Increasing the Targeting of PAMAM as Carriers in Glioma Therapy

Glioma is an invasive brain cancer, and it is difficult to achieve desired therapeutic effects due to the high postoperative recurrence rate and limited efficacy of drug therapy hindered by the biological barrier of brain tissue. Nanodrug delivery systems are of great interest, and many efforts have been made to utilize them for glioma treatment. Polyamidoamine (PAMAM), a starburst dendrimer, provides malleable molecular size, functionalized molecular structure and penetrable brain barrier characteristics. Therefore, PAMAM-based nanodrug delivery systems (PAMAM DDS) are preferred for glioma treatment research. In this review, experimental studies on PAMAM DDS for glioma therapy were focused on and summarized. Emphasis was given to three major topics: methods of drug loading, linkers between drug/ligand and PAMAM and ligands of modified PAMAM. A strategy for well-designed PAMAM DDS for glioma treatment was proposed. Purposefully understanding the physicochemical and structural characteristics of drugs is necessary for selecting drug loading methods and achieving high drug loading capacity. Additionally, functional ligands contribute to achieving the brain targeting, brain penetration and low toxicity of PAMAM DDS. Furthermore, a brilliant linker facilitates multidrug combination and multifunctional PAMAM DDS. PAMAM DDS show excellent promise as drug vehicles and will be further studied for product development and safety evaluation.

Gold nanoparticles: current and upcoming biomedical applications in sensing, drug, and gene delivery

Gold nanoparticles (AuNPs) present unique physicochemical characteristics, low cytotoxicity, chemical stability, size/morphology tunability, surface functionalization capability, and optical properties which can be exploited for detection applications (colorimetry, surface-enhanced Raman scattering, and photoluminescence). The current challenge for AuNPs is incorporating these properties in developing more sensible and selective sensing methods and multifunctional platforms capable of controlled and precise drug or gene delivery. This review briefly highlights the recent progress of AuNPs in biomedicine as bio-sensors and targeted nano vehicles.

Amalgamation of Nanoparticles within Drug Carriers: A Synergistic Approach or a Futile Attempt?

In recent years, nanotechnology has gained much attention from scientists and significant advances in therapeutic potential. Nano-delivery systems have emerged as an effective way in order to improve the therapeutic properties of drugs including solubility, stability, prolongation of half-life as well as promoting the accumulation of drug at the target site. The nanoparticles have also been incorporated into various conventional drug delivery systems. This review study aims to introduce the amalgamation of nanoparticles into drug carriers. To overcome the limitations of single nanoparticles such as toxicity, high instability, rapid drug release as well as limited drug loading capacity, a multi-component system is developed. Liposomes, microparticles, nanofibers, dendrimers etc., are promising drug carriers, having some limitations that can be minimized, and the compilation of nanoparticles synergizes the properties. The amalgamated nanocarriers are used for the diagnostic purpose as well as treatment of various chronic diseases. It also increases the solubility of hydrophobic drugs. However, each system has its advantages and disadvantages based on its physicochemical properties, efficacy, and other parameters. This review details the past and present state of development for the fusion of nanoparticles within drug carriers and from which we identify future research works needed for the same.

Delivering the Promise of Gene Therapy with Nanomedicines in Treating Central Nervous System Diseases

Central Nervous System (CNS) diseases, such as Alzheimer's diseases (AD), Parkinson's Diseases (PD), brain tumors, Huntington's disease (HD), and stroke, still remain difficult to treat by the conventional molecular drugs. In recent years, various gene therapies have come into the spotlight as versatile therapeutics providing the potential to prevent and treat these diseases. Despite the significant progress that has undoubtedly been achieved in terms of the design and modification of genetic modulators with desired potency and minimized unwanted immune responses, the efficient and safe in vivo delivery of gene therapies still poses major translational challenges. Various non-viral nanomedicines have been recently explored to circumvent this limitation. In this review, an overview of gene therapies for CNS diseases is provided and describes recent advances in the development of nanomedicines, including their unique characteristics, chemical modifications, bioconjugations, and the specific applications that those nanomedicines are harnessed to deliver gene therapies.

Surface Engineered Dendrimers: A Potential Nanocarrier for the Effective Management of Glioblastoma Multiforme

Gliomas are the most prevailing intracranial tumors, which account for approximately 36% of the primary brain tumors of glial cells. Glioblastoma multiforme (GBM) possesses a higher degree of malignancy among different gliomas. The blood-brain barrier (BBB) protects the brain against infections and toxic substances by preventing foreign molecules or unwanted cells from entering the brain parenchyma. Nano-carriers such as liposomes, nanoparticles, dendrimers, etc. boost the brain permeability of various anticancer drugs or other drugs. The favorable properties like small size, better solubility, and the modifiable surface of dendrimers have proven their broad applicability in the better management of GBM. However, in vitro and in vivo toxicities caused by dendrimers have been a significant concern. The presence of multiple functionalities on the surface of dendrimers enables the grafting of target ligand and/or therapeutic moieties. Surface engineering improves certain properties like targeting efficiency, pharmacokinetic profile, therapeutic effect, and toxicity reduction. This review will be focused on the role of different surface-modified dendrimers in the effective management of GBM.

Small Interfering RNA for Gliomas Treatment: Overcoming Hurdles in Delivery

Gliomas are central nervous system tumors originating from glial cells, whose incidence and mortality rise in coming years. The current treatment of gliomas is surgery combined with chemotherapy or radiotherapy. However, developing therapeutic resistance is one of the significant challenges. Recent research suggested that small interfering RNA (siRNA) has excellent potential as a therapeutic to silence genes that are significantly involved in the manipulation of gliomas’ malignant phenotypes, including proliferation, invasion, metastasis, therapy resistance, and immune escape. However, it is challenging to deliver the naked siRNA to the action site in the cells of target tissues. Therefore, it is urgent to develop delivery strategies to transport siRNA to achieve the optimal silencing effect of the target gene. However, there is no systematic discussion about siRNAs’ clinical potential and delivery strategies in gliomas. This review mainly discusses siRNAs’ delivery strategies, especially nanotechnology-based delivery systems, as a potential glioma therapy. Moreover, we envisage the future orientation and challenges in translating these findings into clinical applications.

β-Cyclodextrin and Oligoarginine Peptide-Based Dendrimer-Entrapped Gold Nanoparticles for Improving Drug Delivery to the Inner Ear

Here, we developed a safe and highly effective nanocarrier using β-cyclodextrin (β-CD) and oligoarginine peptide (Arg8)-modified dendrimer-entrapped gold nanoparticles (Au@CD-PAMAM-Arg8), with a diameter of 5 nm, for improved delivery of dexamethasone (Dex) to the inner ear. The properties and in vivo distribution of the Au@CD-PAMAM-Arg8 were assessed in vitro, and a streptomycin (SM) ototoxicity model was used in vivo. Flow cytometry analysis of HEIOC1 cells treated with Au@CD-PAMAM-Arg8 and Au @CD-PAMAM at different time intervals indicated that cell uptake efficiency of the drug delivery carrier Au@CD-PAMAM-Arg8 was higher than that of Au @CD-PAMAM. Au@CD-PAMAM-Arg8 carrying Dex (Au@CD-PAMAM-Arg8/Dex) were mainly distributed in hair cells, the spiral ganglion, lateral wall, and nerve fibers and had stronger protective effects on the inner ear than Dex administration alone. In vivo tracer tests revealed that tympanic injection was significantly more effective than posterior ear injection, muscle injection, and tail vein injection, whereas clinical retro-auricular injection could not increase the efficiency of drug delivery into the ear. Electrocochleography results showed that Au@CD-PAMAM-Arg8/Dex significantly improved hearing in C57/BL6 mice after SM exposure. These findings indicate that Au@CD-PAMAM-Arg8 may be the useful drug carriers for the treatment of inner ear diseases.

Recent advances in the therapeutic strategies of glioblastoma multiforme

Glioblastoma multiforme (GBM) is one of the most common, most formidable, and deadliest malignant types of primary astrocytoma with a poor prognosis. At present, the standard of care includes surgical tumor resection, followed by radiation therapy concomitant with chemotherapy and temozolomide. New developments and significant advances in the treatment of GBM have been achieved in recent decades. However, despite the advances, recurrence is often inevitable, and the survival of patients remains low. Various factors contribute to the difficulty in identifying an effective therapeutic option, among which are tumor complexity, the presence of the blood-brain barrier (BBB), and the presence of GBM cancer stem cells, prompting the need for improving existing treatment approaches and investigating new treatment alternatives for ameliorating the treatment strategies of GBM. In this review, we outline some of the most recent literature on the various available treatment options such as surgery, radiotherapy, cytotoxic chemotherapy, gene therapy, immunotherapy, phototherapy, nanotherapy, and tumor treating fields in the treatment of GBM, and we list some of the potential future directions of GBM. The reviewed studies confirm that GBM is a sophisticated disease with several challenges for scientists to address. Hence, more studies and a multimodal therapeutic approach are crucial to yield an effective cure and prolong the survival of GBM patients.

Glycoconjugate Nanoparticle-Based Systems in Cancer Immunotherapy: Novel Designs and Recent Updates

For many years, cell-surface glycans (in particular, Tumor-Associated Carbohydrate Antigens, TACAs) have been the target of both passive and active anticancer immunotherapeutic design. Recent advances in immunotherapy as a treatment for a variety of malignancies has revolutionized anti-tumor treatment regimens. Checkpoint inhibitors, Chimeric Antigen Receptor T-cells, Oncolytic virus therapy, monoclonal antibodies and vaccines have been developed and many approvals have led to remarkable outcomes in a subset of patients. However, many of these therapies are very selective for specific patient populations and hence the search for improved therapeutics and refinement of techniques for delivery are ongoing and fervent research areas. Most of these agents are directed at protein/peptide epitopes, but glycans-based targets are gaining in popularity, and a handful of approved immunotherapies owe their activity to oligosaccharide targets. In addition, nanotechnology and nanoparticle-derived systems can help improve the delivery of these agents to specific organs and cell types based on tumor-selective approaches. This review will first outline some of the historical beginnings of this research area and subsequently concentrate on the last 5 years of work. Based on the progress in therapeutic design, predictions can be made as to what the future holds for increasing the percentage of positive patient outcomes for optimized systems.

siRNA nanohybrid systems: false hope or feasible answer in cancer management

Finding out predisposition and makeup alterations in cancer cells has prompted the exploration of exogenous small interference RNA (siRNA) as a therapeutic agent to deal with cancer. siRNA is subjected to many limitations that hinders its cellular uptake. Various nanocarriers have been loaded with siRNA to improve their cellular transportation and have moved to clinical trials. However, many restrictions as low encapsulation efficiency, nanocarrier cytotoxicity and premature release of siRNA have impeded the single nanocarrier use. The realm of nanohybrid systems has emerged to overcome these limitations and to synergize the criteria of two or more nanocarriers. Different nanohybrid systems that were developed as cellular pathfinders for the exogenous siRNA to target cancer will be illustrated in this review.

Co-delivery of Dexamethasone and a MicroRNA-155 Inhibitor Using Dendrimer-Entrapped Gold Nanoparticles for Acute Lung Injury Therapy

Development of nanomedicines for effective therapy of acute lung injury (ALI), a common critical respiratory failure syndrome, remains to be challenging. We report here a unique design of a functional nanoplatform based on generation 5 (G5) poly(amidoamine) dendrimer-entrapped gold nanoparticles (Au DENPs) to co-deliver dexamethasone (Dex) and a microRNA-155 inhibitor (miR-155i) for combination chemotherapy and gene therapy of ALI. In this study, we synthesized Au DENPs with 10 Dex moieties attached per G5 dendrimer and an Au core diameter of 2.1 nm and used them to compress miR-155i. The generated polyplexes own a positive zeta potential (16-26 mV) and a small hydrodynamic diameter (175-230 nm) and display desired cytocompatibility and efficient miR-155i delivery to lipopolysaccharide (LPS)-activated alveolar macrophages, thus upregulating the suppressor of cytokine signaling 1 and IL-10 expression and downregulating the pro-inflammatory cytokines (TNF-α, IL-1β, and IL-6). Likewise, as a synthetic glucocorticoid with a potent anti-inflammatory property, the attached Dex on the surface of Au DENPs could inhibit pro-inflammatory cytokine secretion by down-regulating cyclooxygenase-2 expression in the LPS-activated alveolar macrophages. The integration of Dex and miR-155i within one nanoformulation enables superior downregulation of pro-inflammatory cytokines for successful repair of damaged lung tissues in an ALI model, as demonstrated by histological examinations and pro-inflammatory cytokine downregulation in ALI lesion at the gene and protein levels. Such a combined chemotherapy and gene therapy strategy enabled by dendrimer nanotechnology may hold great promise to treat other types of inflammatory diseases.

Organic/Inorganic Self-Assembled Hybrid Nano-Architectures for Cancer Therapy Applications

Since the conceptualization of nanomedicine, numerous nanostructure-mediated drug formulations have progressed into clinical trials for treating cancer. However, recent clinical trial results indicate such kind of drug formulations has a limited improvement on the antitumor efficacy. This is due to the biological barriers associated with those formulations, for example, circulation stability, extravasation efficiency in tumor, tumor penetration ability, and developed multi-drug resistance. When employing for nanomedicine formulations, pristine organic-based and inorganic-based nanostructures have their own limitations. Accordingly, organic/inorganic (O/I) hybrids have been developed to integrate the merits of both, and to minimize their intrinsic drawbacks. In this context, the recent development in O/I hybrids resulting from a self-assembly strategy will be introduced. Through such a strategy, organic and inorganic building blocks can be self-assembled via either chemical covalent bonds or physical interactions. Based on the self-assemble procedure, the hybridization of four organic building blocks including liposomes, micelles, dendrimers, and polymeric nanocapsules with five functional inorganic nanoparticles comprising gold nanostructures, magnetic nanoparticles, carbon-based materials, quantum dots, and silica nanoparticles will be highlighted. The recent progress of these O/I hybrids in advanced modalities for combating cancer, such as, therapeutic agent delivery, photothermal therapy, photodynamic therapy, and immunotherapy will be systematically reviewed.

Targeting Non-coding RNA for Glioblastoma Therapy: The Challenge of Overcomes the Blood-Brain Barrier

Glioblastoma (GBM) is the most malignant form of all primary brain tumors, and it is responsible for around 200,000 deaths each year worldwide. The standard therapy for GBM treatment includes surgical resection followed by temozolomide-based chemotherapy and/or radiotherapy. With this treatment, the median survival rate of GBM patients is only 15 months after its initial diagnosis. Therefore, novel and better treatment modalities for GBM treatment are urgently needed. Mounting evidence indicates that non-coding RNAs (ncRNAs) have critical roles as regulators of gene expression. Long non-coding RNAs (lncRNAs) and microRNAs (miRNAs) are among the most studied ncRNAs in health and disease. Dysregulation of ncRNAs is observed in virtually all tumor types, including GBMs. Several dysregulated miRNAs and lncRNAs have been identified in GBM cell lines and GBM tumor samples. Some of them have been proposed as diagnostic and prognostic markers, and as targets for GBM treatment. Most ncRNA-based therapies use oligonucleotide RNA molecules which are normally of short life in circulation. Nanoparticles (NPs) have been designed to increase the half-life of oligonucleotide RNAs. An additional challenge faced not only by RNA oligonucleotides but for therapies designed for brain-related conditions, is the presence of the blood-brain barrier (BBB). The BBB is the anatomical barrier that protects the brain from undesirable agents. Although some NPs have been derivatized at their surface to cross the BBB, optimal NPs to deliver oligonucleotide RNA into GBM cells in the brain are currently unavailable. In this review, we describe first the current treatments for GBM therapy. Next, we discuss the most relevant miRNAs and lncRNAs suggested as targets for GBM therapy. Then, we compare the current drug delivery systems (nanocarriers/NPs) for RNA oligonucleotide delivery, the challenges faced to send drugs through the BBB, and the strategies to overcome this barrier. Finally, we categorize the critical points where research should be the focus in order to design optimal NPs for drug delivery into the brain; and thus move the Oligonucleotide RNA-based therapies from the bench to the clinical setting.

Engineered non-invasive functionalized dendrimer/dendron-entrapped/complexed gold nanoparticles as a novel class of theranostic (radio)pharmaceuticals in cancer therapy

Nanomedicine represents a very significant contribution in current cancer treatment; in addition to surgical intervention, radiation and chemotherapeutic agents that unfortunately also kill healthy cells, inducing highly deleterious and often life-threatening side effects in the patient. Of the numerous nanoparticles used against cancer, gold nanoparticles had been developed for therapeutic applications. Inter alia, a large variety of dendrimers, i.e. soft artificial macromolecules, have turned up as non-viral functional nanocarriers for entrapping drugs, imaging agents, and targeting molecules. This review will provide insights into the design, synthesis, functionalization, and development in biomedicine of engineered functionalized hybrid dendrimer-tangled gold nanoparticles in the domain of cancer theranostic. Several aspects are highlighted and discussed such as 1) dendrimer-entrapped gold(0) hybrid nanoparticles for the targeted imaging and treatment of cancer cells, 2) dendrimer encapsulating gold(0) nanoparticles (Au DENPs) for the delivery of genes, 3) Au DENPs for drug delivery applications, 4) dendrimer encapsulating gold radioactive nanoparticles for radiotherapy, and 5) dendrimer/dendron-complexed gold(III) nanoparticles as technologies to take down cancer cells.

Dendrimer-based nanohybrids in cancer photomedicine

Cancer phototherapy with non-invasiveness and high therapeutical efficiency has emerged as a hot spot research in cancer management. Various nanomaterials have been involved in the development of novel photoactive agents to overcome the current limitations in cancer phototherapy. Dendrimers, as an excellent nanocarrier with unique physicochemical properties, have received extensive attention and much effort has been made in the development of dendrimer-based hybrid platforms for photomedicine applications. Dendrimers can be entrapped with photosensitive agents within their internal cavities and be surface modified with reactive molecules, constructing multifunctional nanoplatforms for cancer treatment. In this review, we concisely survey the design of several different kinds of dendrimer-based nanohybrids for cancer photomedicine applications, and provide an overview of their recent applications in molecular imaging, single-modality photothermal therapy or photodynamic therapy, combination therapy, and theranostics of cancer. In addition, we also briefly discuss the future perspectives in the area of dendrimer-based nanohybrids for cancer photomedicine.

Hybrid Nanosystems for Biomedical Applications

Inorganic/organic hybrid nanosystems have been increasingly developed for their versatility and efficacy at overcoming obstacles not readily surmounted by nonhybridized counterparts. Currently, hybrid nanosystems are implemented for gene therapy, drug delivery, and phototherapy in addition to tissue regeneration, vaccines, antibacterials, biomolecule detection, imaging probes, and theranostics. Though diverse, these nanosystems can be classified according to foundational inorganic/organic components, accessory moieties, and architecture of hybridization. Within this Review, we begin by providing a historical context for the development of biomedical hybrid nanosystems before describing the properties, synthesis, and characterization of their component building blocks. Afterward, we introduce the architectures of hybridization and highlight recent biomedical nanosystem developments by area of application, emphasizing hybrids of distinctive utility and innovation. Finally, we draw attention to ongoing clinical trials before recapping our discussion of hybrid nanosystems and providing a perspective on the future of the field.

Construction of Poly(amidoamine) Dendrimer/Carbon Dot Nanohybrids for Biomedical Applications

Design of intelligent hybrid nanoparticles that can integrate diagnosis and therapy components plays an important role in the field of nanomedicine. Poly(amidoamine) (PAMAM) dendrimers possessing a unique architecture and tunable functional groups have been widely developed for various biomedical applications. Carbon dots (CDs) are considered as a promising fluorescence probe or drug delivery system due to their stable fluorescence property and excellent biocompatibility. The distinctive merits of PAMAM dendrimers and CDs are amenable for them to be constructed as perfect nanohybrids for different biomedical applications, in particular for cancer nanomedicine. Here, the recent advances in the construction of PAMAM dendrimer/CD nanohybrids for diverse biomedical applications, in particular for sensing and cancer theranostics are summarized. Finally, the future perspectives of the PAMAM dendrimer/CD nanohybrids are also briefly discussed.

Recent Progresses in Organic-Inorganic Nano Technological Platforms for Cancer Therapeutics

Nanotechnology offers promising tools in interdisciplinary research areas and getting an upsurge of interest in cancer therapeutics. Organic nanomaterials and inorganic nanomaterials bring revolutionary advancement in cancer eradication process. Oncology is achieving new heights under nano technological platform by expediting chemotherapy, radiotherapy, photo thermodynamic therapy, bio imaging and gene therapy. Various nanovectors have been developed for targeted therapy which acts as "Nano-bullets" for tumor cells selectively. Recently combinational therapies are catching more attention due to their enhanced effect leading towards the use of combined organicinorganic nano platforms. The current review covers organic, inorganic and their hybrid nanomaterials for various therapeutic action. The technological aspect of this review emphasizes on the use of inorganic-organic hybrids and combinational therapies for better results and also explores the future opportunities in this field.

Nanotechnology and Nanocarrier-Based Drug Delivery as the Potential Therapeutic Strategy for Glioblastoma Multiforme: An Update

Simple Summary

Glioblastoma multiforme (GBM) are among the most lethal tumors. The highly invasive nature and presence of GBM stem cells, as well as the blood brain barrier (BBB) which limits chemotherapeutic drugs from entering the tumor mass, account for the high chance of treatment failure. Recent developments have found that nanoparticles can be conjugated to liposomes, dendrimers, metal irons, or polymeric micelles, which enhance the drug-loaded compounds to efficiently penetrate the BBB, thus offering new possibilities for overcoming GBM stem cell-mediated resistance to chemotherapy and radiation therapy. In addition, there have been new emerging strategies that use nanocarriers for successful GBM treatment in animal models. This review highlights the recent development of nanotechnology and nanocarrier-based drug delivery for treatment of GBMs, which may be a promising therapeutic strategy for this tumor entity.

Abstract

Glioblastoma multiforme (GBM) is the most common and malignant brain tumor with poor prognosis. The heterogeneous and aggressive nature of GBMs increases the difficulty of current standard treatment. The presence of GBM stem cells and the blood brain barrier (BBB) further contribute to the most important compromise of chemotherapy and radiation therapy. Current suggestions to optimize GBM patients’ outcomes favor controlled targeted delivery of chemotherapeutic agents to GBM cells through the BBB using nanoparticles and monoclonal antibodies. Nanotechnology and nanocarrier-based drug delivery have recently gained attention due to the characteristics of biosafety, sustained drug release, increased solubility, and enhanced drug bioactivity and BBB penetrability. In this review, we focused on recently developed nanoparticles and emerging strategies using nanocarriers for the treatment of GBMs. Current studies using nanoparticles or nanocarrier-based drug delivery system for treatment of GBMs in clinical trials, as well as the advantages and limitations, were also reviewed.

Targeted Combination of Antioxidative and Anti-Inflammatory Therapy of Rheumatoid Arthritis using Multifunctional Dendrimer-Entrapped Gold Nanoparticles as a Platform

Abundant reactive oxygen species and tumor necrosis factor-α (TNF-α) cytokine supply of M1-type macrophages boost rheumatoid arthritis (RA) pathological process. For efficient RA therapy, here a multifunctional nanoplatform is presented based on generation 5 (G5) poly(amidoamine) dendrimer-entrapped gold nanoparticles (Au DENPs) to achieve co-delivery of antioxidant alpha-tocopheryl succinate (α-TOS) and anti-inflammatory anti-TNF-α siRNA to macrophage cells. G5 dendrimers with amine termini are sequentially functionalized with 1,3-propane sultone (1,3-PS), α-TOS through a polyethylene glycol (PEG) spacer, and PEGylated folic acid (FA), and subsequently entrapped with Au NPs. The generated functional Au DENPs exhibit desired cytocompatibility, zwitterion-rendered antifouling property, and FA-mediated targeting specificity, enabling serum-enhanced siRNA delivery to M1-type macrophage cells. Meanwhile, the attached α-TOS affords enhanced oxidation resistance of macrophage cells. In vivo investigation shows that the treatment of a collagen-induced arthritis mouse model using α-TOS-modified Au DENPs/TNF-α siRNA polyplexes can achieve excellent combination therapy effect in inflammatory cytokines downregulation of RA lesion and bone erosions. The therapeutic efficacy is also supported by 3D micro-computed tomography analysis and TNF-α cytokine reduction of RA lesion joints in the mRNA, protein, and histology levels. The created multifunctional nanoplatform may be employed in antioxidative and anti-inflammatory combination therapy of RA.

PAMAM Dendrimer Nanomolecules Utilized as Drug Delivery Systems for Potential Treatment of Glioblastoma: A Systematic Review

Glioblastoma (GB) is a grade IV astrocytoma that maintains a poor prognosis with respect to current treatment options. Despite major advancements in the fields of surgery and chemoradiotherapy over the last few decades, the life expectancy for someone with glioblastoma remains virtually unchanged and warrants a new approach for treatment. Poly(amidoamine) (PAMAM) dendrimers are a type of nanomolecule that ranges in size (between 1 and 100 nm) and shape and can offer a new viable solution for the treatment of intracranial tumors, including glioblastoma. Their ability to deliver a variety of therapeutic cargo and penetrate the blood-brain barrier (BBB), while preserving low cytotoxicity, make them a favorable candidate for further investigation into the treatment of glioblastoma. Here, we present a systematic review of the current advancements in PAMAM dendrimer technology, including the wide spectrum of dendrimer generations formulated, surface modifications, core modifications, and conjugations developed thus far to enhance tumor specificity and tumor penetration for treatment of glioblastoma. Furthermore, we highlight the extensive variety of therapeutics capable of delivery by PAMAM dendrimers for the treatment of glioblastoma, including cytokines, peptides, drugs, siRNAs, miRNAs, and organic polyphenols. While there have been prolific results stemming from aggressive research into the field of dendrimer technology, there remains a nearly inexhaustible amount of questions that remain unanswered. Nevertheless, this technology is rapidly developing and is nearing the cusp of use for aggressive tumor treatment. To that end, we further highlight future prospects in focus as researchers continue developing more optimal vehicles for the delivery of therapeutic cargo.

Induction of apoptosis through extrinsic/intrinsic pathways and suppression of ERK/NF-κB signalling participate in anti-glioblastoma of imipramine

Glioblastomas are the most aggressive type of brain tumour, with poor prognosis even after standard treatment such as surgical resection, temozolomide and radiation therapy. The overexpression of the nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) in glioblastomas is recognized as an important treatment target. Thus, an urgent need regarding glioblastomas is the development of a new, suitable agent that may show potential for the inhibition of extracellular signal-regulated kinase (ERK)/NF-κB-mediated glioblastoma progression. Imipramine, a tricyclic antidepressant, has anti-inflammatory actions against inflamed glial cells; additionally, imipramine can induce glioblastoma toxicity via the activation of autophagy. However, whether imipramine can suppress glioblastoma progression via the induction of apoptosis and blockage of ERK/NF-κB signalling remains unclear. The main purpose of this study was to investigate the effects of imipramine on apoptotic signalling and ERK/NF-κB-mediated glioblastoma progression by using cell proliferation (3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide [MTT] assay), flow cytometry, Western blotting, and cell invasion/migration assay analysis in vitro. The ERK and NF-κB inhibitory capacity of imipramine is detected by NF-κB reporter gene assay and Western blotting. Additionally, a glioblastoma-bearing animal model was used to validate the therapeutic efficacy and general toxicity of imipramine. Our results demonstrated that imipramine successfully triggered apoptosis through extrinsic/intrinsic pathways and suppressed the invasion/migration ability of glioblastoma cells. Furthermore, imipramine effectively suppressed glioblastoma progression in vivo via the inhibition of the ERK/NF-κB pathway. In summary, imipramine is a potential anti-glioblastoma drug which induces apoptosis and has the capacity to inhibit ERK/NF-κB signalling.

Nanomedicine and Immunotherapy: A Step Further towards Precision Medicine for Glioblastoma

Owing to the advancement of technology combined with our deeper knowledge of human nature and diseases, we are able to move towards precision medicine, where patients are treated at the individual level in concordance with their genetic profiles. Lately, the integration of nanoparticles in biotechnology and their applications in medicine has allowed us to diagnose and treat disease better and more precisely. As a model disease, we used a grade IV malignant brain tumor (glioblastoma). Significant improvements in diagnosis were achieved with the application of fluorescent nanoparticles for intraoperative magnetic resonance imaging (MRI), allowing for improved tumor cell visibility and increasing the extent of the surgical resection, leading to better patient response. Fluorescent probes can be engineered to be activated through different molecular pathways, which will open the path to individualized glioblastoma diagnosis, monitoring, and treatment. Nanoparticles are also extensively studied as nanovehicles for targeted delivery and more controlled medication release, and some nanomedicines are already in early phases of clinical trials. Moreover, sampling biological fluids will give new insights into glioblastoma pathogenesis due to the presence of extracellular vesicles, circulating tumor cells, and circulating tumor DNA. As current glioblastoma therapy does not provide good quality of life for patients, other approaches such as immunotherapy are explored. To conclude, we reason that development of personalized therapies based on a patient's genetic signature combined with pharmacogenomics and immunogenomic information will significantly change the outcome of glioblastoma patients.

Adoptive cellular immunotherapy of tumors via effective CpG delivery to dendritic cells using dendrimer-entrapped gold nanoparticles as a gene vector

PEGylated Au DENPs ({(Au⁰)₂₅-G5·NH₂-mPEG₂₀}) are synthesized and used as a novel nonviral vector to deliver CpG to mature BMDCs for the subsequent activation of T cells for adoptive tumor immunotherapy.

Core-shell tecto dendrimers formed via host-guest supramolecular assembly as pH-responsive intelligent carriers for enhanced anticancer drug delivery

The design of pH-sensitive supramolecular drug delivery systems for efficient antineoplastic drug delivery remains a huge challenge. Herein, we describe the development of pH-responsive core-shell tecto dendrimers (CSTDs) formed using benzimidazole (BM)-modified generation 3 (G3) poly(amidoamine) (PAMAM) dendrimers (G3.NHAc-BM) as a shell and β-cyclodextrin (CD)-modified G5 PAMAM dendrimers (G5.NHAc-CD) as a core. By virtue of the host-guest recognition and pH-responsiveness of BM/β-CD assembly, the pH-sensitive supramolecular CSTDs of G5.NHAc-CD/BM-G3.NHAc were formed and adopted to encapsulate the anticancer drug doxorubicin (DOX) via hydrophobic interactions for pH-responsive drug delivery applications. The synthesis of dendrimer derivatives and the loading of the DOX were well characterized via different methods. We show that the encapsulated DOX can be released in a sustained manner with a rapid release speed under a slightly acidic pH condition (pH < 6), which is similar to acidic tumor microenvironment. The enhanced intracellular release of DOX and improved anticancer activity of the drug-loaded pH-responsive CSTDs were demonstrated and compared with the control CSTDs formed without pH-responsiveness through flow cytometry and viability assays of cancer cells. Furthermore, the pH-sensitive CSTDs also showed efficient drug penetration and growth inhibition of three-dimensional tumor spheroids owing to the faster DOX release in an acidic pH environment. The pH-sensitive G5.NHAc-CD/BM-G3.NHAc CSTDs may be employed as a valuable intelligent delivery system for various anticancer drugs.

Zwitterion-functionalized dendrimer-entrapped gold nanoparticles for serum-enhanced gene delivery to inhibit cancer cell metastasis

We demonstrate a novel serum-enhanced gene delivery approach using zwitterion-functionalized dendrimer-entrapped gold nanoparticles (Au DENPs) as a non-viral vector for inhibition of cancer cell metastasis in vitro. Poly(amidoamine) dendrimers of generation 5 decorated with zwitterion carboxybetaine acrylamide (CBAA) and lysosome-targeting agent morpholine (Mor) were utilized to entrap gold NPs. We show that both Mor-modified and Mor-free Au DENPs are cytocompatible and can effectively deliver plasmid DNA encoding different reporter genes to cancer cells in medium with or without serum. Strikingly, due to the antifouling property exerted by the attached zwitterion CBAA, the gene delivery efficiency of Mor-modified Au DENPs and the Mor-free Au DENPs in the serum-containing medium are 1.4 and 1.7 times higher than the corresponding vector in serum-free medium, respectively. In addition, the Mor-free vector has a better gene expression efficiency than the Mor-modified one although the Mor modification enables the polyplexes to have enhanced cancer cell uptake. Wound healing and hypermethylated in cancer 1 (HIC1) protein expression assay data reveal that the expression of HIC1 gene in cancer cells enables effective inhibition of cell migration. Our findings suggest that the created zwitterion-functionalized Au DENPs may be employed as a powerful vector for serum-enhanced gene therapy of different diseases. STATEMENT OF SIGNIFICANCE: One major challenge in the non-viral gene delivery system is that the strong interaction between serum protein and the positively charged vector/gene polyplexes neutralize the positive charge of the polyplexes and form possible protein corona, thereby significantly reducing their cellular uptake efficiency and subsequent gene transfection outcome. Here we demonstrate the conceptual advances in the serum-enhanced gene delivery using zwitterionic modification of polycationic poly(amidoamine) (PAMAM) dendrimer-entrapped gold nanoparticles (Au DENPs). We demonstrate that partial zwitterionic modification of Au DENPs is able to confer them with antifouling property to resist serum protein adsorption. Hence the vector/DNA polyplexes are able to maintain their positive potentials and small hydrodynamic size in the serum environment, where serum solely play the role as a nutrition factor for enhanced gene delivery. We demonstrate that partial modification of zwitterion carboxybetaine acrylamide (CBAA) and morpholine (Mor) onto the surface Au DENPs renders the vector with both antifouling property and lysosome targeting ability, respectively. The generated functional Au DENPs can compact pDNA to form polyplexes that enable serum-enhanced gene expression. In particular, once complexed with hypermethylated in cancer 1 (HIC1) gene, the polyplexes can significantly inhibit cancer cell migration and metastasis.

In vitro siRNA delivery via diethylenetriamine- and tetraethylenepentamine-modified carboxyl group-terminated Poly(amido)amine generation 4.5 dendrimers

The recent discovery of small interfering RNAs (siRNAs) has opened new avenues for designing personalized treatment options for various diseases. However, the therapeutic application of siRNAs has been confronted with many challenges because of short half-life in circulation, poor membrane penetration, difficulty in escaping from endosomes, and insufficient release into the cytosol. To overcome these challenges, we designed a diethylenetriamine (DETA)- and tetraethylenepentamine (TEPA)-modified polyamidoamine dendrimer generation 4.5 (PDG4.5), and characterized it using ¹H nuclear magnetic resonance (NMR), ¹³C NMR, correlation spectroscopy (COSY), heteronuclear single-quantum correlation spectroscopy (HSQC), and Fourier transform infrared (FTIR) spectroscopy followed by conjugation with siRNA. The PDG4.5-DETA and PDG4.5-TEPA polyplexes exhibited spherical nanosize, ideal zeta potential, and effective siRNA binding ability, protected the siRNA from nuclease attack, and revealed less cytotoxicity of PDG4.5-DETA and PDG4.5-TEPA in HeLa cells. More importantly, the polyplexes also revealed good cellular internalization and facilitated translocation of the siRNA into the cytosol. Thus, PDG4.5-DETA and PDG4.5-TEPA can act as potential siRNA carriers in future medical and pharmaceutical applications.

Structure-activity relationship of novel low-generation dendrimers for gene delivery

Structure-activity relationship (SAR) studies are very critical to design ideal gene vectors for gene delivery. However, It is difficult to obtain SAR information of low-generation dendrimers due to the lack of easy structural modification ways. Here, we synthesized a novel family of rigid aromatic backbone-based low-generation polyamidoamine (PAMAM) dendrimers. According to the number of primary amines, they were divided into two types: four-amine-containing PAMAM (DL1-DL5) and eight-amine-containing PAMAM (DL6-DL10). Due to the introduction of a rigid aromatic backbone, the low-generation PAMAM could be modified easier by different hydrophobic aliphatic chains. Several assays were used to study the interactions of the PAMAM dendrimers with plasmid DNA, and the results revealed that they not only had good DNA binding ability but also could efficiently condense DNA into spherical-shaped nanoparticles with suitable sizes and zeta potentials. The SAR studies indicated that the gene-transfection efficiency of the synthesized materials depended on not only the structure of their hydrophobic chains but also the number of primary amines. It was found that four-amine-containing PAMAM prepared from oleylamine (DL5) gave the best transfection efficiency, which was 3 times higher than that of lipofectamine 2000 in HEK293 cells. The cellular uptake mechanism mediated by DL5 was further investigated, and the results indicated that DL5/DNA complexes entered the cells mainly via caveolae and clathrin-mediated endocytosis. In addition, these low-generation PAMAMs modified with a single hydrophobic tail showed lower toxicity than lipofectamine 2000 in MC3T3-E1, MG63, HeLa, and HEK293 cells. These results reveal that such a type of low-generation polyamidoamines might be promising non-viral gene vectors, and also give us clues for the design of safe and high-efficiency gene vectors.

Nanoformulations for glioblastoma multiforme: a new hope for treatment

Glioblastoma multiforme (GBM) is the most common primary malignant brain tumor in adults, associated with a high mortality rate and a survival of between 12 and 15 months after diagnosis. Due to current treatment limitations involving surgery, radiotherapy and chemotherapy with temozolamide, there is a high rate of treatment failure and recurrence. To try to overcome these limitations nanotechnology has emerged as a novel alternative. Lipid, polymeric, silica and magnetic nanoparticles, among others, are being developed to improve GBM treatment and diagnosis. These nanoformulations have many advantages, including lower toxicity, biocompatibility and the ability to be directed toward the tumor. This article reviews the progress that have been made and the large variety of nanoparticles currently under study for GBM.