Transferrin-targeted porous silicon nanoparticles reduce glioblastoma cell migration across tight extracellular space

Emerging therapeutic strategies in glioblastsoma: drug repurposing, mechanisms of resistance, precision medicine, and technological innovations

Glioblastoma (GBM) is an aggressive Grade IV brain tumor with a poor prognosis. It results from genetic mutations, epigenetic changes, and factors within the tumor microenvironment (TME). Traditional treatments like surgery, radiotherapy, and chemotherapy provide limited survival benefits due to the tumor's heterogeneity and resistance mechanisms. This review examines novel approaches for treating GBM, focusing on repurposing existing medications such as antipsychotics, antidepressants, and statins for their potential anti-GBM effects. Advances in molecular profiling, including next-generation sequencing, artificial intelligence (AI), and nanotechnology-based drug delivery, are transforming GBM diagnosis and treatment. The TME, particularly GBM stem cells and immune evasion, plays a key role in therapeutic resistance. Integrating multi-omics data and applying precision medicine show promise, especially in combination therapies and immunotherapies, to enhance clinical outcomes. Addressing challenges such as drug resistance, targeting GBM stem cells, and crossing the blood-brain barrier is essential for improving treatment efficacy. While current treatments offer limited benefits, emerging strategies such as immunotherapies, precision medicine, and drug repurposing show significant potential. Technologies like liquid biopsies, AI-powered diagnostics, and nanotechnology could help overcome obstacles like the blood-brain barrier and GBM stem cells. Ongoing research into combination therapies, targeted drug delivery, and personalized treatments is crucial. Collaborative efforts and robust clinical trials are necessary to translate these innovations into effective therapies, offering hope for improved survival and quality of life for GBM patients.

Co-delivery of hsa-miR-34a and 3-methyl adenine by a self-assembled cellulose-based nanocarrier for enhanced anti-tumor effects in HCC

The simultaneous delivery of oligonucleotides and small molecules has garnered significant interest in cancer therapy. Hepatocellular carcinoma (HCC) treatment is hindered by limited efficacy and significant side effects. Homo sapiens microRNA-34a (hsa-miR-34a) has tumor suppressor properties and like small molecule 3-methyl adenine (3MA) can inhibit autophagy. Besides, 3MA has been shown to enhance anticancer effects in combination therapies. In the present study, a novel modified-cellulose-dialdehyde (MDAC) nanocarrier responsive to lysosomal pH was designed to co-load hsa-miR-34a polyplexes and 3MA and evaluate its antitumor efficacy against HCC. Polyplexes containing hsa-miR-34a and poly L lysine (PLL) with an optimal N/P ratio exhibited a zeta potential of +9.28. These polycations significantly modulated the surface charge of 3MA MDAC for optimal cell-membrane transport and dramatically increased their stability. The PLL-miR34a/3MA MDAC NPs had loading efficiency of around 99.7 % for miR-34a and 35 % for 3MA. Comply with pH dependency, PLL-miR34a polyplex/3MA MDAC NPs worked very efficiently on the inhibiting the expression of autophagy genes (p < 0.05), preventing the formation of autophagosomal vacuoles, reducing rate of cell survival, anti-migratory effects (>100 %), and triggering apoptosis (67.15 %) in HepG2. Our cellulose-based nanocarrier may demonstrate potential for enhancing therapeutic efficacy of combination therapies headed for future clinical translation in HCC.

Modern insights of nanotheranostics in the glioblastoma: An updated review

Glioblastoma multiforme (GBM) is a highly malignant subtype of glioma, originating from the glial cells that provide support to other neurons in the brain. GBM predominantly impacts the cerebral hemisphere of the brain, with minimal effects on the cerebellum, brain stem, or spinal cord. Individuals diagnosed with GBM commonly encounter a range of symptoms, starting from auditory abnormalities to seizures. Recently, cell membrane-camouflaged nanoparticles (CMCNPs) are evolving as promising theranostic agents that can carry specific biological moieties from their biological origin and effectively target GBM cells. Moreover, exosomes have gained widespread scientific attention as an effective drug delivery approach due to their excellent stability in the bloodstream, high biocompatibility, low immune response, and inherent targeting capabilities. Exosomes derived from specific cell types can transport endogenous signaling molecules that have therapeutic promise for GBM therapy. In this context, researchers are utilizing various techniques to isolate exosomes from liquid biomarkers from patients, such as serum and cerebrospinal fluid (CSF). Proper isolation of exosomes may induce the clinical diagnosis in GBM due to their commercial accessibility and real-time monitoring options. Since exosomes are unable to penetrate the blood-brain barrier (BBB), strategic theranostic methods are ideal. For this, understanding interactions between glioma-specific exosomes in the TME and biomarkers is necessary. The versatile characteristics of NPs and their capacity to cross the BBB enable them to be indispensable against GBM. In this review article, we discussed the recent theranostic applications of nanotechnology by comparing the limitations of existing nanotechnology-based approaches.

Sustained Release of HIF-2α Inhibitors Using Biodegradable Porous Silicon Carriers for Enhanced Immunogenic Cell Death of Malignant Merkel Cell Carcinoma

Merkel cell carcinoma (MCC) is a rare but aggressive neuroendocrine skin cancer with limited treatment options, often associated with Merkel cell polyomavirus (MCPyV) and marked by hypoxic tumor microenvironments that promote resistance to therapies. Belzutifan, an FDA-approved hypoxia-inducible factor-2α (HIF-2α) inhibitor, has shown promise in inhibiting tumor growth; however, its clinical efficacy is hindered by its low solubility, rapid clearance, and limited bioavailability. In this study, we present a strategy using porous silicon (pSi) microparticles and nanoparticles as carriers for the sustained delivery of benzoate to MCC cells. The pSi carriers were engineered to securely encapsulate and gradually release belzutifan, overcoming the limitations of free drug administration. Microparticles provided sustained extracellular release, while nanoparticles enabled efficient intracellular delivery, enhancing HIF-2α inhibition. Moreover, the use of biodegradable silicon particles enables long-term consistent release of belzutifan over 10 days in vitro with a single dose administration in the tumor microenvironment, while free belzutifan is rapidly deactivated within 1 day postadministration. In vitro studies demonstrated significant immunogenic cell death (ICD) in MCC cells, marked by the cytosolic localization of HMGB1 and elevated expression of pro-inflammatory cytokines as well as strong upregulation of TLR9. Particularly, the increased TLR9 expression in both MCC cell lines with pSi carrier treatment reinforces immune activation through toll-like receptor signaling, enhancing both innate and adaptive immune responses within the tumor microenvironment. These findings indicate that pSi carriers not only enhance belzutifan's stability and release profile but also amplify antitumor immune responses within the tumor microenvironment. Our results suggest that belzutifan-loaded pSi carriers offer a potent and targeted therapeutic strategy for MCC, potentially addressing key challenges in cancer immunotherapy by combining HIF-2α inhibition with robust immune activation. This platform highlights the universal utility of pSi-based delivery systems to advance MCC treatment with implications for broader cancer therapies.

Advancing glioblastoma treatment through iron metabolism: A focus on TfR1 and Ferroptosis innovations

Glioblastoma (GBM) represents a formidable challenge in oncology, characterized by aggressive proliferation and poor prognosis. Iron metabolism plays a critical player in GBM progression, with dysregulated iron uptake and utilization contributing to tumor growth and therapeutic resistance. Iron's pivotal role in DNA synthesis, oxidative stress, and angiogenesis underscores its significance in GBM pathogenesis. Elevated expression of iron transporters, such as transferrin receptor 1 (TfR1), highlights the tumor's reliance on iron for survival. Innovative treatment strategies targeting iron dysregulation hold promise for overcoming therapeutic challenges in GBM management. Approaches such as iron chelation therapies, induction of ferroptosis to nanoparticle-based drug delivery systems exploit iron-dependent vulnerabilities, offering avenues for enhance treatment efficacy and improve patient outcomes. As research advances, understanding the complexities of iron-mediated carcinogenesis provides a foundation for developing precision medicine approaches tailored to combat GBM effectively. This review explores the intricate relationship between iron metabolism and GBM, elucidating its multifaceted implications and therapeutic opportunities. By consolidating the latest insights into iron metabolism in GBM, this review underscores its potential as a therapeutic target for improving patient care in combination with the standard of care approach.

Use of surface-modified porous silicon nanoparticles to deliver temozolomide with enhanced pharmacokinetic and therapeutic efficacy for intracranial glioblastoma in mice

Glioblastoma (GBM) is one of the most common and fatal primary brain tumors, with a 5-year survival rate of 7.2%. The standard treatment for GBM involves surgical resection followed by chemoradiotherapy, and temozolomide (TMZ) is currently the only approved chemotherapeutic agent for the treatment of GBM. However, hydrolytic instability and insufficient drug accumulation are major challenges that limit the effectiveness of TMZ chemotherapy. To overcome these limitations, we have developed a drug delivery platform utilizing porous silicon nanoparticles (pSiNPs) to improve the stability and blood-brain barrier penetration of TMZ. The pSiNPs are synthesized via electrochemical etching and functionalized with octadecane. The octadecyl-modified pSiNP (pSiNP-C18) demonstrates the superiority of loading efficiency, in vivo stability, and brain accumulation of TMZ. Treatment of intracranial tumor-bearing mice with TMZ-loaded pSiNP-C18 results in a decreased tumor burden and a corresponding increase in survival compared with equivalent free-drug dosing. Furthermore, the mice treated with TMZ-loaded nanoparticles do not exhibit in vivo toxicity, thus underscoring the preclinical potential of the pSiNP-based platform for the delivery of therapeutic agents to gliomas.

Evidence That a Peptide-Drug/p53 Gene Complex Promotes Cognate Gene Expression and Inhibits the Viability of Glioblastoma Cells

Glioblastoma multiform (GBM) is considered the deadliest brain cancer. Conventional therapies are followed by poor patient survival outcomes, so novel and more efficacious therapeutic strategies are imperative to tackle this scourge. Gene therapy has emerged as an exciting and innovative tool in cancer therapy. Its combination with chemotherapy has significantly improved therapeutic outcomes. In line with this, our team has developed temozolomide-transferrin (Tf) peptide (WRAP5)/p53 gene nanometric complexes that were revealed to be biocompatible with non-cancerous cells and in a zebrafish model and were able to efficiently target and internalize into SNB19 and U373 glioma cell lines. The transfection of these cells, mediated by the formulated peptide-drug/gene complexes, resulted in p53 expression. The combined action of the anticancer drug with p53 supplementation in cancer cells enhances cytotoxicity, which was correlated to apoptosis activation through quantification of caspase-3 activity. In addition, increased caspase-9 levels revealed that the intrinsic or mitochondrial pathway of apoptosis was implicated. This assumption was further evidenced by the presence, in glioma cells, of Bax protein overexpression-a core regulator of this apoptotic pathway. Our findings demonstrated the great potential of peptide TMZ/p53 co-delivery complexes for cellular transfection, p53 expression, and apoptosis induction, holding promising therapeutic value toward glioblastoma.

Decoding Nanomaterial-Biosystem Interactions through Machine Learning

The interactions between biosystems and nanomaterials regulate most of their theranostic and nanomedicine applications. These nanomaterial-biosystem interactions are highly complex and influenced by a number of entangled factors, including but not limited to the physicochemical features of nanomaterials, the types and characteristics of the interacting biosystems, and the properties of the surrounding microenvironments. Over the years, different experimental approaches coupled with computational modeling have revealed important insights into these interactions, although many outstanding questions remain unanswered. The emergence of machine learning has provided a timely and unique opportunity to revisit nanomaterial-biosystem interactions and to further push the boundary of this field. This minireview highlights the development and use of machine learning to decode nanomaterial-biosystem interactions and provides our perspectives on the current challenges and potential opportunities in this field.

Silicon-containing nanomedicine and biomaterials: materials chemistry, multi-dimensional design, and biomedical application

The invention of silica-based bioactive glass in the late 1960s has sparked significant interest in exploring a wide range of silicon-containing biomaterials from the macroscale to the nanoscale. Over the past few decades, these biomaterials have been extensively explored for their potential in diverse biomedical applications, considering their remarkable bioactivity, excellent biocompatibility, facile surface functionalization, controllable synthesis, etc. However, to expedite the clinical translation and the unexpected utilization of silicon-composed nanomedicine and biomaterials, it is highly desirable to achieve a thorough comprehension of their characteristics and biological effects from an overall perspective. In this review, we provide a comprehensive discussion on the state-of-the-art progress of silicon-composed biomaterials, including their classification, characteristics, fabrication methods, and versatile biomedical applications. Additionally, we highlight the multi-dimensional design of both pure and hybrid silicon-composed nanomedicine and biomaterials and their intrinsic biological effects and interactions with biological systems. Their extensive biomedical applications span from drug delivery and bioimaging to therapeutic interventions and regenerative medicine, showcasing the significance of their rational design and fabrication to meet specific requirements and optimize their theranostic performance. Additionally, we offer insights into the future prospects and potential challenges regarding silicon-composed nanomedicine and biomaterials. By shedding light on these exciting research advances, we aspire to foster further progress in the biomedical field and drive the development of innovative silicon-composed nanomedicine and biomaterials with transformative applications in biomedicine.

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.

Fabrication, in-silico, in-vitro, and in-vivo characterization of transferrin-targeted micelles containing cisplatin and gadolinium for improved theranostic applications in lung cancer therapy

The targeted delivery of therapeutic and imaging agents is quite challenging in lung cancer therapy. Thus, lung cancer causes high mortality across the world. Herein, we developed TPGS-PF127 micelles containing cisplatin (CDDP) as a model anticancer drug and gadolinium (Gd) as a diagnostic agent by a slightly modified solvent casting method, further, the surface of the micelles was modified using TPGS-transferrin (TPGS-Tf) conjugate to improve targeted delivery of micelles to the lung cancer cells. Prior to this, the binding affinity of Tf over TfR (1E7U) and TfR (1E8W) was investigated with the help of in-silico studies. In-silico results showed good docking scores -7.8 and -7.2 kcal/mol of Tf -ligand towards 1E8W and 1E7U respectively promoting PI3K inhibition. Micelles have shown an average particle size range of 80-200 nm and have shown spherical morphology. The encapsulation efficiency of cisplatin (CDDP) in the CPT, CGPT, and CGPT-Tf micelles ranged from 75.63 % ± 1.58 % to 85.07 % ± 2.65 %. Furthermore, the encapsulation efficiency of gadolinium (Gd) in the CGPT and CGPT-Tf micelles was found to be 67.50 ± 0.32 % and 62.52 ± 0.52 %, respectively. CGPT-Tf micelles exhibited sustained release fashion for CDDP up to 48 h in physiological conditions. In the cytotoxicity study, CGPT-Tf micelles achieved higher cytotoxicity and caused a more antiproliferative effect in A549 cells compared to a commercial CDDP injection (Ciszest 50), after 24 h of treatment. Furthermore, the pharmacokinetic studies have proven the pharmacological effectiveness of developed CGPT-Tf micelles by achieving higher Cmax, Tmax, t1/2, and MRT of CDDP in systemic circulation compared to its counterparts and Ciszest 50. In lung theranostic observations, a higher internalization of Gd was noted in CGPT-TF compared to free Gd. The biochemical studies have proved the biocompatibility of developed micelles formulations by showing no sign of toxicity in the lungs. The developed micelles have great potential to be utilized in treating and diagnosing a wide variety of cancers.

Influence of Surface Ligand Density and Particle Size on the Penetration of the Blood-Brain Barrier by Porous Silicon Nanoparticles

Overcoming the blood-brain barrier (BBB) remains a significant challenge with regard to drug delivery to the brain. By incorporating targeting ligands, and by carefully adjusting particle sizes, nanocarriers can be customized to improve drug delivery. Among these targeting ligands, transferrin stands out due to the high expression level of its receptor (i.e., transferrin receptor) on the BBB. Porous silicon nanoparticles (pSiNPs) are a promising drug nanocarrier to the brain due to their biodegradability, biocompatibility, and exceptional drug-loading capacity. However, an in-depth understanding of the optimal nanoparticle size and transferrin surface density, in order to maximize BBB penetration, is still lacking. To address this gap, a diverse library of pSiNPs was synthesized using bifunctional poly(ethylene glycol) linkers with methoxy or/and carboxyl terminal groups. These variations allowed us to explore different transferrin surface densities in addition to particle sizes. The effects of these parameters on the cellular association, uptake, and transcytosis in immortalized human brain microvascular endothelial cells (hCMEC/D3) were investigated using multiple in vitro systems of increasing degrees of complexity. These systems included the following: a 2D cell culture, a static Transwell model, and a dynamic BBB-on-a-chip model. Our results revealed the significant impact of both the ligand surface density and size of pSiNPs on their ability to penetrate the BBB, wherein intermediate-level transferrin densities and smaller pSiNPs exhibited the highest BBB transportation efficiency in vitro. Moreover, notable discrepancies emerged between the tested in vitro assays, further emphasizing the necessity of using more physiologically relevant assays, such as a microfluidic BBB-on-a-chip model, for nanocarrier testing and evaluation.

Breast Cancer Cell Type and Biomechanical Properties of Decellularized Mouse Organs Drives Tumor Cell Colonization

Tissue engineering has emerged as an indispensable tool for the reconstruction of organ-specific environments. Organ-derived extracellular matrices (ECM) and, especially, decellularized tissues (DCL) are recognized as the most successful biomaterials in regenerative medicine, as DCL preserves the most essential organ-specific ECM properties such as composition alongside biomechanics characterized by stiffness and porosity. Expansion of the DCL technology to cancer biology research, drug development, and nanomedicine is pending refinement of the existing DCL protocols whose reproducibility remains sub-optimal varying from organ to organ. We introduce a facile decellularization protocol universally applicable to murine organs, including liver, lungs, spleen, kidneys, and ovaries, with demonstrated robustness, reproducibility, high purification from cell debris, and architecture preservation, as confirmed by the histological and SEM analysis. The biomechanical properties of as-produced DCL organs expressed in terms of the local and total stiffness were measured using our facile methodology and were found well preserved in comparison with the intact organs. To demonstrate the utility of the developed DCL model to cancer research, we engineered three-dimensional tissue constructs by recellularization representative decellularized organs and collagenous hydrogel with human breast cancer cells of pronounced mesenchymal (MDA-MB-231) or epithelial (SKBR-3) phenotypes. The biomechanical properties of the DCL organs were found pivotal to determining the cancer cell fate and progression. Our histological and scanning electron microscopy (SEM) study revealed that the larger the ECM mean pore size and the smaller the total stiffness (as in lung and ovary), the more proliferative and invasive the mesenchymal cells became. At the same time, the low local stiffness ECMs (ranged 2.8-3.6 kPa) did support the epithelial-like SKBR-3 cells' viability (as in lung and spleen), while stiff ECMs did not. The total and local stiffness of the collagenous hydrogel was measured too low to sustain the proliferative potential of both cell lines. The observed cell proliferation patterns were easily interpretable in terms of the ECM biomechanical properties, such as binding sites, embedment facilities, and migration space. As such, our three-dimensional tissue engineering model is scalable and adaptable for pharmacological testing and cancer biology research of metastatic and primary tumors, including early metastatic colonization in native organ-specific ECM.

Quantifying Intracellular Nanoparticle Distributions with Three-Dimensional Super-Resolution Microscopy

Super-resolution microscopy can transform our understanding of nanoparticle-cell interactions. Here, we established a super-resolution imaging technology to visualize nanoparticle distributions inside mammalian cells. The cells were exposed to metallic nanoparticles and then embedded within different swellable hydrogels to enable quantitative three-dimensional (3D) imaging approaching electron-microscopy-like resolution using a standard light microscope. By exploiting the nanoparticles' light scattering properties, we demonstrated quantitative label-free imaging of intracellular nanoparticles with ultrastructural context. We confirmed the compatibility of two expansion microscopy protocols, protein retention and pan-expansion microscopy, with nanoparticle uptake studies. We validated relative differences between nanoparticle cellular accumulation for various surface modifications using mass spectrometry and determined the intracellular nanoparticle spatial distribution in 3D for entire single cells. This super-resolution imaging platform technology may be broadly used to understand the nanoparticle intracellular fate in fundamental and applied studies to potentially inform the engineering of safer and more effective nanomedicines.

Nanoparticles for Drug and Gene Delivery in Pediatric Brain Tumors' Cancer Stem Cells: Current Knowledge and Future Perspectives

Primary malignant brain tumors are the most common solid neoplasm in childhood. Despite recent advances, many children affected by aggressive or metastatic brain tumors still present poor prognosis, therefore the development of more effective therapies is urgent. Cancer stem cells (CSCs) have been discovered and isolated in both pediatric and adult patients with brain tumors (e.g., medulloblastoma, gliomas and ependymoma). CSCs are a small clonal population of cancer cells responsible for brain tumor initiation, maintenance and progression, displaying resistance to conventional anticancer therapies. CSCs are characterized by a specific repertoire of surface markers and intracellular specific pathways. These unique features of CSCs biology offer the opportunity to build therapeutic approaches to specifically target these cells in the complex tumor bulk. Treatment of pediatric brain tumors with classical chemotherapeutic regimen poses challenges both for tumor location and for the presence of the blood-brain barrier (BBB). Lastly, the application of chemotherapy to a developing brain is followed by long-term sequelae, especially on cognitive abilities. Novel avenues are emerging in the therapeutic panorama taking advantage of nanomedicine. In this review we will summarize nanoparticle-based approaches and the efficacy that NPs have intrinsically demonstrated and how they are also decorated by biomolecules. Furthermore, we propose novel cargoes together with recent advances in nanoparticle design/synthesis with the final aim to specifically target the insidious CSCs population in the tumor bulk.

A Multifunctional Porous Silicon Nanocarrier for Glioblastoma Treatment

Clinical treatment of glioblastoma (GBM) remains a major challenge because of the blood-brain barrier, chemotherapeutic resistance, and aggressive tumor metastasis. The development of advanced nanoplatforms that can efficiently deliver drugs and gene therapies across the BBB to the brain tumors is urgently needed. The protein "downregulated in renal cell carcinoma" (DRR) is one of the key drivers of GBM invasion. Here, we engineered porous silicon nanoparticles (pSiNPs) with antisense oligonucleotide (AON) for DRR gene knockdown as a targeted gene and drug delivery platform for GBM treatment. These AON-modified pSiNPs (AON@pSiNPs) were selectively internalized by GBM and human cerebral microvascular endothelial cells (hCMEC/D3) cells expressing Class A scavenger receptors (SR-A). AON was released from AON@pSiNPs, knocked down DRR and inhibited GBM cell migration. Additionally, a penetration study in a microfluidic-based BBB model and a biodistribution study in a glioma mice model showed that AON@pSiNPs could specifically cross the BBB and enter the brain. We further demonstrated that AON@pSiNPs could carry a large payload of the chemotherapy drug temozolomide (TMZ, 1.3 mg of TMZ per mg of NPs) and induce a significant cytotoxicity in GBM cells. On the basis of these results, the nanocarrier and its multifunctional strategy provide a strong potential for clinical treatment of GBM and research for targeted drug and gene delivery.

Development of WRAP5 Peptide Complexes for Targeted Drug/Gene Co-Delivery toward Glioblastoma Therapy

Despite the great progress over the past few decades in both the diagnosis and treatment of a great variety of human cancers, glioblastoma remains the most lethal brain tumor. In recent years, cancer gene therapy focused on non-viral vectors which emerged as a promising approach to glioblastoma treatment. Transferrin (Tf) easily penetrates brain cells of the blood–brain barrier, and its receptor is highly expressed in this barrier and glioblastoma cells. Therefore, the development of delivery systems containing Tf appears as a reliable strategy to improve their brain cells targeting ability and cellular uptake. In this work, a cell-penetrating peptide (WRAP5), bearing a Tf-targeting sequence, has been exploited to condense tumor suppressor p53-encoding plasmid DNA (pDNA) for the development of nanocomplexes. To increase the functionality of developed nanocomplexes, the drug Temozolomide (TMZ) was also incorporated into the formulations. The physicochemical properties of peptide/pDNA complexes were revealed to be dependent on the nitrogen to phosphate groups ratio and can be optimized to promote efficient cellular internalization. A confocal microscopy study showed the capacity of developed complexes for efficient glioblastoma cell transfection and consequent pDNA delivery into the nucleus, where efficient gene expression took place, followed by p53 protein production. Of promise, these peptide/pDNA complexes induced a significant decrease in the viability of glioblastoma cells. The set of data reported significantly support further in vitro research to evaluate the therapeutic potential of developed complexes against glioblastoma.

The role of imaging in targeted delivery of nanomedicine for cancer therapy

Nanomedicines overcome the pharmacokinetic limitations of traditional drug formulations and have promising prospect in cancer treatment. However, nanomedicine delivery in vivo is still facing challenges from the complex physiological environment. For the purpose of effective tumor therapy, they should be designed to guarantee the five features principle, including long blood circulation, efficient tumor accumulation, deep matrix penetration, enhanced cell internalization and accurate drug release. To ensure the excellent performance of the designed nanomedicine, it would be better to monitor the drug delivery process as well as the therapeutic effects by real-time imaging. In this review, we summarize strategies in developing nanomedicines for efficiently meeting the five features of drug delivery, and the role of several imaging modalities (fluorescent imaging (FL), magnetic resonance imaging (MRI), computed tomography (CT), photoacoustic imaging (PAI), positron emission tomography (PET), and electron microscopy) in tracing drug delivery and therapeutic effect in vivo based on five features principle.

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.

Cell penetrating peptide decorated magnetic porous silicon nanorods for glioblastoma therapy and imaging

Glioblastoma multiforme (GBM) is the most malignant primary brain tumor of the central nervous system. Despite advances in therapy, it remains largely untreatable, in part due to the low permeability of chemotherapeutic drugs across the blood-brain barrier (BBB) which significantly compromises their effectiveness. To circumvent the lack of drug efficiency, we designed multifunctional nanoparticles based on porous silicon. Herein, we propose an innovative synthesis technique for porous silicon nanorods (pSiNRs) with three-dimensional (3D) shape-controlled nanostructure. In order to achieve an efficient administration and improved treatment against GBM cells, a porous silicon nanoplatform is designed with magnetic guidance, fluorescence tracking and a cell-penetrating peptide (CPP). A NeuroFilament Light (NFL) subunit derived 24 amino acid tubulin binding site peptide called NFL-TBS.40-63 peptide or NFL-peptide was reported to preferentially target human GBM cells compared to healthy cells. Motivated by this approach, we investigated the use of magnetic-pSiNRs covered with superparamagnetic iron oxide nanoparticles (SPIONs) for magnetic guidance, then decorated with the NFL-peptide to facilitate targeting and enhance internalization into human GBM cells. Unexpectedly, under confocal microscope imaging, the internalized multifunctional nanoparticles in GBM cells induce a remarkable exaltation of green fluorescence instead of the red native fluorescence from the dye due to a possible Förster resonance energy transfer (FRET). In addition, we showed that the uptake of NFL-peptide decorated magnetic-pSiNRs was preferential towards human GBM cells. This study presents the fabrication of magnetic-pSiNRs decorated with the NFL-peptide, which act as a remarkable candidate to treat brain tumors. This is supported by in vitro results and confocal imaging.

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.

Two-photon-excited tumor cell fluorescence targeted imaging based on transferrin-functionalized silicon nanoparticles

Transferrin-functionalized silicon nanoparticles (Trf-SiNPs) were fabricated and utilized for targeted fluorescence imaging in tumor cells. Silicon nanoparticles (SiNPs) was firstly synthesized by microwave irradiation method, and then coupled with transferrin in the presence of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (EDC) and N-hydroxysuccinimide (NHS). The structural informations of Trf-SiNPs were measured by transmission electron microscope and Fourier transform infrared spectrometer. The optical properties of Trf-SiNPs were characterized by ultraviolet absorption spectrum, fluorescence emission spectrum, fluorescence quantum yield, fluorescence lifetime, photo-stability, and so on. MTT assay evidenced the low toxicity of Trf-SiNPs. Finally, Trf-SiNPs were successfully applied in HeLa cells and HepG2 cells for targeted fluorescence imaging under single-photon excitation and two-photon excitation.

Transferrin Receptor-Targeted Nanocarriers: Overcoming Barriers to Treat Glioblastoma

Glioblastoma multiforme (GBM) is the most common and lethal type of brain tumor, and the clinically available approaches for its treatment are not curative. Despite the intensive research, biological barriers such as the blood–brain barrier (BBB) and tumor cell membranes are major obstacles to developing novel effective therapies. Nanoparticles (NPs) have been explored as drug delivery systems (DDS) to improve GBM therapeutic strategies. NPs can circumvent many of the biological barriers posed by this devastating disease, enhancing drug accumulation in the target site. This can be achieved by employing strategies to target the transferrin receptor (TfR), which is heavily distributed in BBB and GBM cells. These targeting strategies comprise the modification of NPs’ surface with various molecules, such as transferrin (Tf), antibodies, and targeting peptides. This review provides an overview and discussion on the recent advances concerning the strategies to target the TfR in the treatment of GBM, as their benefits and limitations.

Strategies for developing complex multi-component in vitro tumor models: Highlights in glioblastoma

In recent years, many research groups have begun to utilize bioengineered in vitro models of cancer to study mechanisms of disease progression, test drug candidates, and develop platforms to advance personalized drug treatment options. Due to advances in cell and tissue engineering over the last few decades, there are now a myriad of tools that can be used to create such in vitro systems. In this review, we describe the considerations one must take when developing model systems that accurately mimic the in vivo tumor microenvironment (TME) and can be used to answer specific scientific questions. We will summarize the importance of cell sourcing in models with one or multiple cell types and outline the importance of choosing biomaterials that accurately mimic the native extracellular matrix (ECM) of the tumor or tissue that is being modeled. We then provide examples of how these two components can be used in concert in a variety of model form factors and conclude by discussing how biofabrication techniques such as bioprinting and organ-on-a-chip fabrication can be used to create highly reproducible complex in vitro models. Since this topic has a broad range of applications, we use the final section of the review to dive deeper into one type of cancer, glioblastoma, to illustrate how these components come together to further our knowledge of cancer biology and move us closer to developing novel drugs and systems that improve patient outcomes.

Combining Nanotechnology and Gas Plasma as an Emerging Platform for Cancer Therapy: Mechanism and Therapeutic Implication

Nanomedicine and plasma medicine are innovative and multidisciplinary research fields aiming to employ nanotechnology and gas plasma to improve health-related treatments. Especially cancer treatment has been in the focus of both approaches because clinical response rates with traditional methods that remain improvable for many types of tumor entities. Here, we discuss the recent progress of nanotechnology and gas plasma independently as well as in the concomitant modality of nanoplasma as multimodal platforms with unique capabilities for addressing various therapeutic issues in oncological research. The main features, delivery vehicles, and nexus between reactivity and therapeutic outcomes of nanoparticles and the processes, efficacy, and mechanisms of gas plasma are examined. Especially that the unique feature of gas plasma technology, the local and temporally controlled deposition of a plethora of reactive oxygen, and nitrogen species released simultaneously might be a suitable additive treatment to the use of systemic nanotechnology therapy approaches. Finally, we focus on the convergence of plasma and nanotechnology to provide a suitable strategy that may lead to the required therapeutic outcomes.

Dissecting the Inorganic Nanoparticle-Driven Interferences on Adhesome Dynamics

Inorganic nanoparticles have emerged as an attractive theranostic tool applied to different pathologies such as cancer. However, the increment in inorganic nanoparticle application in biomedicine has prompted the scientific community to assess their potential toxicities, often preventing them from entering clinical settings. Cytoskeleton network and the related adhesomes nest are present in most cellular processes such as proliferation, migration, and cell death. The nanoparticle treatment can interfere with the cytoskeleton and adhesome dynamics, thus inflicting cellular damage. Therefore, it is crucial dissecting the molecular mechanisms involved in nanoparticle cytotoxicity. This review will briefly address the main characteristics of different adhesion structures and focus on the most relevant effects of inorganic nanoparticles with biomedical potential on cellular adhesome dynamics. Besides, the review put into perspective the use of inorganic nanoparticles for cytoskeleton targeting or study as a versatile tool. The dissection of the molecular mechanisms involved in the nanoparticle-driven interference of adhesome dynamics will facilitate the future development of nanotheranostics targeting cytoskeleton and adhesomes to tackle several diseases, such as cancer.

Long-term migratory velocity measurements of single glioma cells using microfluidics

Microfluidic platforms enabling single-cell measurements notably contribute to the identification and observation of rare cancer cells that are involved in tumor invasion. Most aggressive, invasive, and heterogeneous glioblastoma cells cause incurable primary brain tumors. Infiltrating gliomas of a brain tumor microenvironment have been intensively studied using conventional assays. Still, quantitative, simple, and precise tools are required for long-term, steady-state migratory-velocity measurements of single glioma cells. To measure long-term velocity changes and investigate the heterogeneity of glioma cells under different growth conditions, we developed a microfluidic platform. We cultured U87 glioma cells in the microfluidic device using either regular growth medium or conditional medium composed of 50% basal medium and 50% macrophage-depleted medium. We microscopically monitored the behavior of 40 glioma cells for 5 days. Using acquired images, we calculated cellular circularity and determined the migratory velocities of glioma cells from 60 h to 120 h. The mean migratory velocity values of the glioma cells were 1.513 μm h^-1 in the basal medium and 3.246 μm h^-1 in the conditional medium. The circularity values of the glioma cells decreased from 0.20-0.25 to 0.15-0.20 when cultured in the conditional medium. Here, we clearly showed that the glioma cells lost their circularity and increased their steady-state velocities; in other words, they adopted an invasive glioma phenotype in the presence of macrophage-depleted medium. Besides, the heterogeneity of the circularity and the velocity of glioma cells were enhanced in the conditional medium.

Transferrin-Decorated Niosomes with Integrated InP/ZnS Quantum Dots and Magnetic Iron Oxide Nanoparticles: Dual Targeting and Imaging of Glioma

The development of multifunctional nanoscale systems that can mediate efficient tumor targeting, together with high cellular internalization, is crucial for the diagnosis of glioma. The combination of imaging agents into one platform provides dual imaging and allows further surface modification with targeting ligands for specific glioma detection. Herein, transferrin (Tf)-decorated niosomes with integrated magnetic iron oxide nanoparticles (MIONs) and quantum dots (QDs) were formulated (PEGNIO/QDs/MIONs/Tf) for efficient imaging of glioma, supported by magnetic and active targeting. Transmission electron microscopy confirmed the complete co-encapsulation of MIONs and QDs in the niosomes. Flow cytometry analysis demonstrated enhanced cellular uptake of the niosomal formulation by glioma cells. In vitro imaging studies showed that PEGNIO/QDs/MIONs/Tf produces an obvious negative-contrast enhancement effect on glioma cells by magnetic resonance imaging (MRI) and also improved fluorescence intensity under fluorescence microscopy. This novel platform represents the first niosome-based system which combines magnetic nanoparticles and QDs, and has application potential in dual-targeted imaging of glioma.

Frontiers in the treatment of glioblastoma: Past, present and emerging

Glioblastoma (GBM) is one of the most aggressive cancers of the brain. Despite extensive research over the last several decades, the survival rates for GBM have not improved and prognosis remains poor. To date, only a few therapies are approved for the treatment of GBM with the main reasons being: 1) significant tumour heterogeneity which promotes the selection of resistant subpopulations 2) GBM induced immunosuppression and 3) fortified location of the tumour in the brain which hinders the delivery of therapeutics. Existing therapies for GBM such as radiotherapy, surgery and chemotherapy have been unable to reach the clinical efficacy necessary to prolong patient survival more than a few months. This comprehensive review evaluates the current and emerging therapies including those in clinical trials that may potentially improve both targeted delivery of therapeutics directly to the tumour site and the development of agents that may specifically target GBM. Particular focus has also been given to emerging delivery technologies such as focused ultrasound, cellular delivery systems nanomedicines and immunotherapy. Finally, we discuss the importance of developing novel materials for improved delivery efficacy of nanoparticles and therapeutics to reduce the suffering of GBM patients.

Effectiveness of porous silicon nanoparticle treatment at inhibiting the migration of a heterogeneous glioma cell population

BACKGROUND

Approximately 80% of brain tumours are gliomas. Despite treatment, patient mortality remains high due to local metastasis and relapse. It has been shown that transferrin-functionalised porous silicon nanoparticles (Tf@pSiNPs) can inhibit the migration of U87 glioma cells. However, the underlying mechanisms and the effect of glioma cell heterogeneity, which is a hallmark of the disease, on the efficacy of Tf@pSiNPs remains to be addressed.

RESULTS

Here, we observed that Tf@pSiNPs inhibited heterogeneous patient-derived glioma cells' (WK1) migration across small perforations (3 μm) by approximately 30%. A phenotypical characterisation of the migrated subpopulations revealed that the majority of them were nestin and fibroblast growth factor receptor 1 positive, an indication of their cancer stem cell origin. The treatment did not inhibit cell migration across large perforations (8 μm), nor cytoskeleton formation. This is in agreement with our previous observations that cellular-volume regulation is a mediator of Tf@pSiNPs' cell migration inhibition. Since aquaporin 9 (AQP9) is closely linked to cellular-volume regulation, and is highly expressed in glioma, the effect of AQP9 expression on WK1 migration was investigated. We showed that WK1 migration is correlated to the differential expression patterns of AQP9. However, AQP9-silencing did not affect WK1 cell migration across perforations, nor the efficacy of cell migration inhibition mediated by Tf@pSiNPs, suggesting that AQP9 is not a mediator of the inhibition.

CONCLUSION

This in vitro investigation highlights the unique therapeutic potentials of Tf@pSiNPs against glioma cell migration and indicates further optimisations that are required to maximise its therapeutic efficacies.

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.

Ion Channels as Therapeutic Targets in High Grade Gliomas

Simple Summary

Glioblastoma multiforme is an aggressive grade IV lethal brain tumour with a median survival of 14 months. Despite surgery to remove the tumour, and subsequent concurrent chemotherapy and radiotherapy, there is little in terms of effective treatment options. Because of this, exploring new treatment avenues is vital. Brain tumours are intrinsically electrically active; expressing unique patterns of ion channels, and this is a characteristic we can exploit. Ion channels are specialised proteins in the cell’s membrane that allow for the passage of positive and negatively charged ions in and out of the cell, controlling membrane potential. Membrane potential is a crucial biophysical signal in normal and cancerous cells. Research has identified that specific classes of ion channels not only move the cell through its cell cycle, thus encouraging growth and proliferation, but may also be essential in the development of brain tumours. Inhibition of sodium, potassium, calcium, and chloride channels has been shown to reduce the capacity of glioblastoma cells to grow and invade. Therefore, we propose that targeting ion channels and repurposing commercially available ion channel inhibitors may hold the key to new therapeutic avenues in high grade gliomas.

Abstract

Glioblastoma multiforme (GBM) is a lethal brain cancer with an average survival of 14–15 months even with exhaustive treatment. High grade gliomas (HGG) represent the leading cause of CNS cancer-related death in children and adults due to the aggressive nature of the tumour and limited treatment options. The scarcity of treatment available for GBM has opened the field to new modalities such as electrotherapy. Previous studies have identified the clinical benefit of electrotherapy in combination with chemotherapeutics, however the mechanistic action is unclear. Increasing evidence indicates that not only are ion channels key in regulating electrical signaling and membrane potential of excitable cells, they perform a crucial role in the development and neoplastic progression of brain tumours. Unlike other tissue types, neural tissue is intrinsically electrically active and reliant on ion channels and their function. Ion channels are essential in cell cycle control, invasion and migration of cancer cells and therefore present as valuable therapeutic targets. This review aims to discuss the role that ion channels hold in gliomagenesis and whether we can target and exploit these channels to provide new therapeutic targets and whether ion channels hold the mechanistic key to the newfound success of electrotherapies.

Advances in Laser Ablation Synthesized Silicon-Based Nanomaterials for the Prevention of Bacterial Infection

Nanomaterials have unique properties and characteristics derived from their shape and small size that are not present in bulk materials. If size and shape are decisive, the synthesis method used, which determines the above parameters, is equally important. Among the different nanomaterial’s synthesis methods, we can find chemical methods (microemulsion, sol-gel, hydrothermal treatments, etc.), physical methods (evaporation-condensation, laser treatment, etc.) and biosynthesis. Among all of them, the use of laser ablation that allows obtaining non-toxic nanomaterials (absence of foreign compounds) with a controlled 3D size, has emerged in recent years as a simple and versatile alternative for the synthesis of a wide variety of nanomaterials with numerous applications. This manuscript reviews the latest advances in the use of laser ablation for the synthesis of silicon-based nanomaterials, highlighting its usefulness in the prevention of bacterial infection.

Multimodal Decorations of Mesoporous Silica Nanoparticles for Improved Cancer Therapy

The presence of leaky vasculature and the lack of lymphatic drainage of small structures by the solid tumors formulate nanoparticles as promising delivery vehicles in cancer therapy. In particular, among various nanoparticles, the mesoporous silica nanoparticles (MSN) exhibit numerous outstanding features, including mechanical thermal and chemical stability, huge surface area and ordered porous interior to store different anti-cancer therapeutics with high loading capacity and tunable release mechanisms. Furthermore, one can easily decorate the surface of MSN by attaching ligands for active targeting specifically to the cancer region exploiting overexpressed receptors. The controlled release of drugs to the disease site without any leakage to healthy tissues can be achieved by employing environment responsive gatekeepers for the end-capping of MSN. To achieve precise cancer chemotherapy, the most desired delivery system should possess high loading efficiency, site-specificity and capacity of controlled release. In this review we will focus on multimodal decorations of MSN, which is the most demanding ongoing approach related to MSN application in cancer therapy. Herein, we will report about the recently tried efforts for multimodal modifications of MSN, exploiting both the active targeting and stimuli responsive behavior simultaneously, along with individual targeted delivery and stimuli responsive cancer therapy using MSN.