Molecular Engineering of Ultrasmall Silica Nanoparticle-Drug Conjugates as Lung Cancer Therapeutics

Nanoparticle-Based Drug Delivery Systems in Inhaled Therapy: Improving Respiratory Medicine

Inhaled nanoparticle (NP) therapy poses intricate challenges in clinical and pharmacodynamic realms. Recent strides have revolutionized NP technology by enabling the incorporation of diverse molecules, thus circumventing systemic clearance mechanisms and enhancing drug effectiveness while mitigating systemic side effects. Despite the established success of systemic NP delivery in oncology and other disciplines, the exploration of inhaled NP therapies remains relatively nascent. NPs loaded with bronchodilators or anti-inflammatory agents exhibit promising potential for precise distribution throughout the bronchial tree, offering targeted treatment for respiratory diseases. This article conducts a comprehensive review of NP applications in respiratory medicine, highlighting their merits, ranging from heightened stability to exacting lung-specific delivery. It also explores cutting-edge technologies optimizing NP-loaded aerosol systems, complemented by insights gleaned from clinical trials. Furthermore, the review examines the current challenges and future prospects in NP-based therapies. By synthesizing current data and perspectives, the article underscores the transformative promise of NP-mediated drug delivery in addressing chronic conditions such as chronic obstructive pulmonary disease, a pressing global health concern ranked third in mortality rates. This overview illuminates the evolving landscape of NP inhalation therapies, presenting optimistic avenues for advancing respiratory medicine and improving patient outcomes.

On chip synthesis of a pH sensitive gefitinib anticancer drug nanocarrier based on chitosan/alginate natural polymers

In this research, using a microfluidic chip, a nanocarrier for the anticancer drug gefitinib was synthesized. Chitosan and alginate natural polymers were utilized for the synthesis of the nanocarrier. The synthesis of the nanocarrier comprises the interaction of secondary amine functional groups of gefitinib molecules with carboxylate functional groups of alginate polymer to form the primary nucleus followed by the formation of the nanocarrier through the self-assembly of chitosan and alginate polymers on a fabricated microfluidic chip. The chip was fabricated by laser engraving poly(methyl methacrylate) polymer sheets. The nanocarrier was characterized by FT-IR, DLS, SEM, and TEM techniques. The synthesized nanocarrier had a size distribution of 5.30 ± 2.60 nm and the encapsulation efficiency percent was 68.4% in the optimum conditions. The loading efficiency was calculated as 50.2 mg g-1 of nanocarrier. Drug release studies showed that the nanocarrier is sensitive to pH and releases more gefitinib in acidic environments. Cytotoxicity of the synthesized nanocarrier was studied on the A549 non-small cell lung cancer, and the MTT test showed that the synthesized nanocarrier has a lower IC50 value than the free drug. Also, the cytotoxicity studies showed that the materials used for the synthesis of nanocarrier do not show significant cytotoxicity. Compared to the previously reported method, the developed microfluidic-assisted method showed advantages such as a faster synthesis procedure and comparable encapsulation efficiency and loading capacity.

Overcoming Barriers Associated with Oral Delivery of Differently Sized Fluorescent Core-Shell Silica Nanoparticles

Oral delivery, while a highly desirable form of nanoparticle-drug administration, is limited by challenges associated with overcoming several biological barriers. Here, the authors study how fluorescent and poly(ethylene glycol)-coated (PEGylated) core-shell silica nanoparticles sized 5 to 50 nm interact with major barriers including intestinal mucus, intestinal epithelium, and stomach acid. From imaging fluorescence correlation spectroscopy studies using quasi-total internal reflection fluorescence microscopy, diffusion of nanoparticles through highly scattering mucus is progressively hindered above a critical hydrodynamic size around 20 nm. By studying Caco-2 cell monolayers mimicking the intestinal epithelia, it is observed that ultrasmall nanoparticles below 10 nm diameter (Cornell prime dots, [C' dots]) show permeabilities correlated with high absorption in humans from primarily enhanced passive passage through tight junctions. Particles above 20 nm diameter exclusively show active transport through cells. After establishing C' dot stability in artificial gastric juice, in vivo oral gavage experiments in mice demonstrate successful passage through the body followed by renal clearance without protein corona formation. Results suggest C' dots as viable candidates for oral administration to patients with a proven pathway towards clinical translation and may generate renewed interest in examining silica as a food additive and its effects on nutrition and health.

Modified gefitinib conjugated Fe3O4 NPs for improved delivery of chemo drugs following an image-guided mechanistic study of inner vs. outer tumor uptake for the treatment of non-small cell lung cancer

Gefitinib (GEF) is an FDA-approved anti-cancer drug for the first-line treatment of patients with metastatic non-small cell lung cancer (NSCLC). However, the efficacy of anticancer drugs is limited due to their non-specificity, lower accumulation at target sites, and systemic toxicity. Herein, we successfully synthesized a modified GEF (mGEF) drug and conjugated to Iron oxide nanoparticles (Fe3O4 NPs) for the treatment of NSCLC via magnetic resonance (MR) image-guided drug delivery. A traditional EDC coupling pathway uses mGEF to directly conjugate to Fe3O4 NPs to overcom the drug leakage issues. As a result, we found in vitro drug delivery on mGEF- Fe3O4 NPs exhibits excellent anticancer effects towards the PC9 cells selectively, with an estimated IC 50 value of 2.0 μM. Additionally, in vivo MRI and PET results demonstrate that the NPs could accumulate in tumor-specific regions with localized cell growth inhibition. Results also revealed that outer tumor region exhibiting a stronger contrast than the tinner tumor region which may due necrosis in inner tumor region. In vivo biodistribution further confirms Fe3O4 NPs are more biocompatible and are excreated after the treatment. Overall, we believe that this current strategy of drug modification combined with chemical conjugation on magnetic NPs will lead to improved cancer chemotherapy as well as understanding the tumor microenvironments for better therapeutic outcomes.

Renal Clearable Quantum Dot-Drug Conjugates Modulate Labile Iron Species and Scavenge Free Radicals for Attenuating Chemotherapeutic Drug-Induced Acute Kidney Injury

Chemotherapeutic drug-induced acute kidney injury (AKI) involves pathologically increased labile iron species in the kidneys that mediate the excessive generation of reactive oxygen species (ROS) to induce ferroptosis and apoptosis, subsequently driving renal dysfunction. Herein, we report renal clearable quantum dot-drug conjugates (QDCs) composed of carbon quantum dot (CDs), deferoxamine (DFO), and poly(ethylene glycol) (PEG) for attenuating chemotherapeutic drug-induced AKI. The CDs component in QDCs can not only provide DFO with high renal specificity to effectively remove the pathological labile iron species in the kidneys to block the source of ROS generation but also exert high antioxidative effects to avoid renal oxidative damage caused by the ROS that have been overproduced. In cisplatin-induced AKI mice, QDCs can inhibit ferroptosis and apoptosis with high efficacy for AKI treatment. This study will provide a new paradigm to realize enhanced therapeutic efficacy for AKI by simultaneously removing the pathological labile iron species and eliminating overproduced ROS in the kidneys to achieve the goal of addressing both symptoms and root causes.

Engineered Ultrasmall Nanoparticle Drug-Immune Conjugates with "Hit and Run" Tumor Delivery to Eradicate Gastric Cancer

Despite advances by recently approved antibody-drug conjugates in treating advanced gastric cancer patients, substantial limitations remain. Here, several key obstacles are overcome by developing a first-in-class ultrasmall (sub-8-nanometer (nm)) anti-human epidermal growth factor receptor 2 (HER2)-targeting drug-immune conjugate nanoparticle therapy. This multivalent fluorescent core-shell silica nanoparticle bears multiple anti-HER2 single-chain variable fragments (scFv), topoisomerase inhibitors, and deferoxamine moieties. Most surprisingly, drawing upon its favorable physicochemical, pharmacokinetic, clearance, and target-specific dual-modality imaging properties in a "hit and run" approach, this conjugate eradicated HER2-expressing gastric tumors without any evidence of tumor regrowth, while exhibiting a wide therapeutic index. Therapeutic response mechanisms are accompanied by the activation of functional markers, as well as pathway-specific inhibition. Results highlight the potential clinical utility of this molecularly engineered particle drug-immune conjugate and underscore the versatility of the base platform as a carrier for conjugating an array of other immune products and payloads.

Ultrasmall silica nanoparticles in translational biomedical research: Overview and outlook

The exemplary progress of silica nanotechnology has attracted extensive attention across a range of biomedical applications such as diagnostics and imaging, drug delivery, and therapy of cancer and other diseases. Ultrasmall silica nanoparticles (USNs) have emerged as a particularly promising class demonstrating unique properties that are especially suitable for and have shown great promise in translational and clinical biomedical research. In this review, we discuss synthetic strategies that allow precise engineering of USNs with excellent control over size and surface chemistry, functionalization, and pharmacokinetic and toxicological profiles. We summarize the current state-of-the-art in the biomedical applications of USNs with a particular focus on select clinical studies. Finally, we illustrate long-standing challenges in the translation of inorganic nanotechnology, particularly in the context of ultrasmall nanomedicines, and provide our perspectives on potential solutions and future opportunities in accelerating the translation and widespread adoption of USN technology in biomedical research.

Nano-based targeted drug delivery for lung cancer: therapeutic avenues and challenges

Most anticancer drugs often fail in clinical trials due to poor solubility, poor bioavailability, lack of targeted delivery and several off-target effects. Polymeric nanoparticles such as poly(lactide), poly(lactic-co-glycolic acid), ALB-loading paclitaxel (Abraxane® ABI-007), lomustine-loaded chitosan, gelatin (decorated with EGF receptor-targeted biotinylated EGF) and so on offer controlled and sustained drug-release properties, biocompatibility and promising anticancer effects. EGF, folic acid, transferrin, sigma and urokinase plasminogen activator receptors-targeting nano preparations improve bioavailability and accumulate drugs on the lung tumor cell surface. However, route of administration, size, pharmacokinetic properties, immune clearance and so on hamper nanomedicines' clinical uses. This review focuses on the benefits, avenues and challenges of nanoparticle-based drug-delivery systems for lung cancer treatment.

Silica nanoparticles: Biomedical applications and toxicity

Silica nanoparticles (SiNPs) are composed of silicon dioxide, the most abundant compound on Earth, and are used widely in many applications including the food industry, synthetic processes, medical diagnosis, and drug delivery due to their controllable particle size, large surface area, and great biocompatibility. Building on basic synthetic methods, convenient and economical strategies have been developed for the synthesis of SiNPs. Numerous studies have assessed the biomedical applications of SiNPs, including the surface and structural modification of SiNPs to target various cancers and diagnose diseases. However, studies on the in vitro and in vivo toxicity of SiNPs remain in the exploratory stage, and the toxicity mechanisms of SiNPs are poorly understood. This review covers recent studies on the biomedical applications of SiNPs, including their uses in drug delivery systems to diagnose and treat various diseases in the human body. SiNP toxicity is discussed in terms of the different systems of the human body and the individual organs in those systems. This comprehensive review includes both fundamental discoveries and exploratory progress in SiNP research that may lead to practical developments in the future.

Ultrasmall Nanoparticle Delivery of Doxorubicin Improves Therapeutic Index for High-Grade Glioma

Purpose: Despite dramatic growth in the number of small molecule drugs developed to treat solid tumors, durable therapeutic options to control primary central nervous system malignancies are relatively scarce. Chemotherapeutic agents which appear biologically potent in model systems have often been found to be marginally effective at best when given systemically in clinical trials. This work presents for the first time an ultrasmall (< 8 nm) multimodal core-shell silica nanoparticle, Cornell prime dots (or C' dots), for the efficacious treatment of high-grade gliomas. Experimental Design: This work presents first-in-kind renally-clearable ultrasmall (< 8 nm) multimodal Cornell prime dots (or C' dots) with surface-conjugated doxorubicin via pH-sensitive linkers for the efficacious treatment in two different clinically relevant high-grade glioma models. Results: Optimal drug-per-particle ratios of as-developed nanoparticle-drug conjugates were established and used to obtain favorable pharmacokinetic profiles. The in vivo efficacy results showed significantly improved biological, therapeutic, and toxicological properties over the native drug after intravenous administration in platelet-derived growth factor-driven genetically engineered mouse model, and an epidermal growth factor expressing patient-derived xenograft (EGFR PDX) model. Conclusions: Ultrasmall C' dot-drug conjugates showed great translational potential over doxorubicin for improving the therapeutic outcome of patients with high-grade gliomas, even without a cancer-targeting moiety.

Addressing Particle Compositional Heterogeneities in Super-Resolution-Enhanced Live-Cell Ratiometric pH Sensing with Ultrasmall Fluorescent Core-Shell Aluminosilicate Nanoparticles

The interrogation of metabolic parameters like pH in live-cell experiments using optical super-resolution microscopy (SRM) remains challenging. This is due to a paucity of appropriate metabolic probes enabling live-cell SRM-based sensing. Here we introduce ultrasmall fluorescent core-shell aluminosilicate nanoparticle sensors (FAM-ATTO647N aC' dots) that covalently encapsulate a reference dye (ATTO647N) in the core and a pH-sensing moiety (FAM) in the shell. Only the reference dye exhibits optical blinking enabling live-cell stochastic optical reconstruction microscopy (STORM). Using data from cells incubated for 60 minutes with FAM-ATTO647N aC' dots, pixelated information from total internal reflection fluorescence (TIRF) microscopy-based ratiometric sensing can be combined with that from STORM-based localizations via the blinking reference dye in order to enhance the resolution of ratiometric pH sensor maps beyond the optical diffraction limit. A nearest-neighbor interpolation methodology is developed to quantitatively address particle compositional heterogeneity as determined by separate single-particle fluorescence imaging methods. When combined with STORM-based estimates of the number of particles per vesicle, vesicle size, and vesicular motion as a whole, this analysis provides detailed live-cell spatial and functional information, paving the way to a comprehensive mapping and understanding of the spatiotemporal evolution of nanoparticle processing by cells important, e.g. for applications in nanomedicine.

New horizons in early drugs development in solid cancers

PURPOSE OF REVIEW

Drug development is the process of bringing new anticancer agents into clinical practice. From the basic research to clinical research each step is essential and intimately linked. The aim of this review is to describe emerging preclinical models and to provide an overview of selected drugs recently developed in oncology.

RECENT FINDINGS

Preclinical models reproducing human immune-tumor interactions, 3D cell cultures and microfluidic platforms are of great interest for the development of immunotherapies and combination therapies and offer the opportunity to better understand the interplay between cancer and stromal cells.Following a better biological understanding of cancer and advances in precision oncology, new exciting drugs (e.g. antibodies-drugs conjugates [ADCs], immunotherapeutic strategies, molecular-targeted therapies) have entered the field of clinical research and even clinical practice.

SUMMARY

Recent improvements in preclinical models will allow an accurate selection of drug candidates for clinical research. Innovative drugs are currently being developed from early to later phases of development. An important remaining challenge in drug development is to set up a new model of patient-centered clinical research to facilitate quick access to innovation and target-oriented trials.

Highway to Success—Developing Advanced Polymer Therapeutics

Polymer therapeutics are advancing as an important class of drugs. Polymers have already demonstrated their value in extending the half‐life of proteins. They show great potential as delivery systems for improving the therapeutic index of drugs, via biophysical targeting and more recently with more precision targeting. They are also important for intracellular delivery of nucleic acid based drugs. The same frameworks that have been successfully applied to improve the small molecule drug development can be adopted. This approach together with improved pathophysiological disease knowledge and critical developability considerations, imperative given the size and complexity of polymer therapeutics, provides a structured framework that should improve their clinical translation and exploit their functionality and potential. Progress in understanding the right target, gaining the right tissue and cell exposure, ensuring the right safety, selecting the right patient population is discussed. The right commercial considerations are outlined and the need for a multi‐disciplinary approach is emphasized. Crucial developability factors together with scientific and technical advancements to enable pharmaceutical development of a quality robust product are addressed. It is argued that by applying this structured approach to their design and development, polymer therapeutics will continue to grow and develop as important next generation medicines.

Ultrasmall, Bright, and Photostable Fluorescent Core-Shell Aluminosilicate Nanoparticles for Live-Cell Optical Super-Resolution Microscopy

Stochastic optical reconstruction microscopy (STORM) is an optical super-resolution microscopy (SRM) technique that traditionally requires toxic and non-physiological imaging buffers and setups that are not conducive to live-cell studies. It is observed that ultrasmall (<10 nm) fluorescent core-shell aluminosilicate nanoparticles (aC' dots) covalently encapsulating organic fluorophores enable STORM with a single excitation source and in a regular (non-toxic) imaging buffer. It is shown that fourfold coordinated aluminum is responsible for dye blinking, likely via photoinduced redox processes. It is demonstrated that this phenomenon is observed across different dye families leading to probes brighter and more photostable than the parent free dyes. Functionalization of aC' dots with antibodies allows targeted fixed cell STORM imaging. Finally, aC' dots enable live-cell STORM imaging providing quantitative measures of the size of intracellular vesicles and the number of particles per vesicle. The results suggest the emergence of a powerful ultrasmall, bright, and photostable optical SRM particle platform with characteristics relevant to clinical translation for the quantitative assessment of cellular structures and processes from live-cell imaging.