Analysis of human innate immune responses to PRINT fabricated nanoparticles with cross validation using a humanized mouse model

Lessons learned from immunological characterization of nanomaterials at the Nanotechnology Characterization Laboratory

Nanotechnology carriers have become common in pharmaceutical products because of their benefits to drug delivery, including reduced toxicities and improved efficacy of active pharmaceutical ingredients due to targeted delivery, prolonged circulation time, and controlled payload release. While available examples of reduced drug toxicity through formulation using a nanocarrier are encouraging, current data also demonstrate that nanoparticles may change a drug’s biodistribution and alter its toxicity profile. Moreover, individual components of nanoparticles and excipients commonly used in formulations are often not immunologically inert and contribute to the overall immune responses to nanotechnology-formulated products. Said immune responses may be beneficial or adverse depending on the indication, dose, dose regimen, and route of administration. Therefore, comprehensive toxicology studies are of paramount importance even when previously known drugs, components, and excipients are used in nanoformulations. Recent data also suggest that, despite decades of research directed at hiding nanocarriers from the immune recognition, the immune system’s inherent property of clearing particulate materials can be leveraged to improve the therapeutic efficacy of drugs formulated using nanoparticles. Herein, I review current knowledge about nanoparticles’ interaction with the immune system and how these interactions contribute to nanotechnology-formulated drug products’ safety and efficacy through the lens of over a decade of nanoparticle characterization at the Nanotechnology Characterization Laboratory.

Power in Numbers: Harnessing Combinatorial and Integrated Screens to Advance Nanomedicine

Nanocarriers have significant potential to advance personalized medicine through targeted drug delivery. However, to date, efforts to improve nanoparticle accumulation at target disease sites have largely failed to translate clinically, stemming from an incomplete understanding of nano-bio interactions. While progress has been made to evaluate the effects of specific physical and chemical nanoparticle properties on trafficking and uptake, there is much to be gained from controlling these properties singularly and in combination to determine their interactions with different cell types. We and others have recently begun leveraging library-based nanoparticle screens to study structure-function relationships of lipid- and polymer-based drug delivery systems to guide nanoparticle design. These combinatorial screening efforts are showing promise in leading to the successful identification of critical characteristics that yield improved and specific accumulation at target sites. However, there is a crucial need to equally consider the influence of biological complexity on nanoparticle delivery, particularly in the context of clinical translation. For example, tissue and cellular heterogeneity presents an additional dimension to nanoparticle trafficking, uptake, and accumulation; applying imaging and screening tools as well as bioinformatics may further expand our understanding of how nanoparticles engage with cells and tissues. Given recent advances in the fields of omics and machine learning, there is substantial promise to revolutionize nanocarrier development through the use of integrated screens, harnessing the combinatorial parameter space afforded both by nanoparticle libraries and clinically annotated biological data sets in combination with high throughput in vivo studies.

Implications of nanotechnology for the treatment of cancer: Recent advances

The use of nanoparticles dramatically increases the safety and efficacy of the most common anticancer drugs. The main advantages of nano-drugs and delivery systems based on nano-technology are effective targeting, delayed release, increased half-life, and less systemic toxicity. The use of nano-carriers has led to significant improvements in drug delivery to targets compared with traditional administration of these drugs. In this review, the main tendencies in nano-drug formulations as well as factors limiting their use in clinical settings are discussed. Additionally, the current status of approved nano-drugs for cancer treatment is reviewed.

A CRISPR/Cas9 based polymeric nanoparticles to treat/inhibit microbial infections

The latest breakthrough towards the adequate and decisive methods of gene editing tools provided by CRISPR/Cas9 (Clustered Regularly Interspaced Short Palindromic Repeat/CRISPR Associated System), has been repurposed into a tool for genetically engineering eukaryotic cells and now considered as the major innovation in gene-related disorders. Nanotechnology has provided an alternate way to overcome the conventional problems where methods to deliver therapeutic agents have failed. The use of nanotechnology has the potential to safe-side the CRISPR/Cas9 components delivery by using customized polymeric nanoparticles for safety and efficacy. The pairing of two (CRISPR/Cas9 and nanotechnology) has the potential for opening new avenues in therapeutic use. In this review, we will discuss the most recent advances in developing nanoparticle-based CRISPR/Cas9 gene editing cargo delivery with a focus on several polymeric nanoparticles including fabrication proposals to combat microbial infections.

Synthetic multivalency for biological applications

Current directions and emerging possibilities under investigation for the integration of synthetic and semi-synthetic multivalent architectures with biology are discussed. Attention is focussed around multivalent interactions, their fundamental role in biology, and current and potential approaches in emulating them in terms of structure and functionality using synthetic architectures.

Pulmonary Delivery of Butyrylcholinesterase as a Model Protein to the Lung

Pulmonary delivery has great potential for delivering biologics to the lung if the challenges of maintaining activity, stability, and ideal aerosol characteristics can be overcome. To study the interactions of a biologic in the lung, we chose butyrylcholinesterase (BuChE) as our model enzyme, which has application for use as a bioscavenger protecting against organophosphate exposure or for use with pseudocholinesterase deficient patients. In mice, orotracheal administration of free BuChE resulted in 72 h detection in the lungs and 48 h in the broncheoalveolar lavage fluid (BALF). Free BuChE administered to the lung of all mouse backgrounds (Nude, C57BL/6, and BALB/c) showed evidence of an acute cytokine (IL-6, TNF-α, MIP2, and KC) and cellular immune response that subsided within 48 h, indicating relatively safe administration of this non-native biologic. We then developed a formulation of BuChE using Particle Replication in Non-Wetting Templates (PRINT). Aerosol characterization demonstrated biologically active BuChE 1 μm cylindrical particles with a mass median aerodynamic diameter of 2.77 μm, indicative of promising airway deposition via dry powder inhalers (DPI). Furthermore, particulate BuChE delivered via dry powder insufflation showed residence time of 48 h in the lungs and BALF. The in vivo residence time, immune response, and safety of particulate BuChE delivered via a pulmonary route, along with the cascade impaction distribution of dry powder PRINT BuChE, showed promise in the ability to deliver active enzymes with ideal deposition characteristics. These findings provide evidence for the feasibility of optimizing the use of BuChE in the clinic; PRINT BuChE particles can be readily formulated for use in DPIs, providing a convenient and effective treatment option.

Materials design at the interface of nanoparticles and innate immunity

Engineered nanoparticle platforms have been developed intensely in recent years, yielding significantly broadened applications from interrogating novel biology to new therapies. Using these platforms requires improved understanding of design rules to improve our ability to control nanoparticle-immune system interactions.

Clinical experiences with systemically administered siRNA-based therapeutics in cancer

Small interfering RNA (siRNA)-based therapies are emerging as a promising new anticancer approach, and a small number of Phase I clinical trials involving patients with solid tumours have now been completed. Encouraging results from these pioneering clinical studies show that these new therapeutics can successfully and safely inhibit targeted gene products in patients with cancer, and have taught us important lessons regarding appropriate dosages and schedules. In this Review, we critically assess these Phase I studies and discuss their implications for future clinical trial design. Key challenges and future directions in the development of siRNA-containing anticancer therapeutics are also considered.

Towards programming immune tolerance through geometric manipulation of phosphatidylserine

The possibility of engineering the immune system in a targeted fashion using biomaterials such as nanoparticles has made considerable headway in recent years. However, little is known as to how modulating the spatial presentation of a ligand augments downstream immune responses. In this report we show that geometric manipulation of phosphatidylserine (PS) through fabrication on rod-shaped PLGA nanoparticles robustly dampens inflammatory responses from innate immune cells while promoting T regulatory cell abundance by impeding effector T cell expansion. This response depends on the geometry of PS presentation as both PS liposomes and 1 micron cylindrical PS-PLGA particles are less potent signal inducers than 80 × 320 nm rod-shaped PS-PLGA particles for an equivalent dose of PS. We show that this immune tolerizing effect can be co-opted for therapeutic benefit in a mouse model of multiple sclerosis and an assay of organ rejection using a mixed lymphocyte reaction with primary human immune cells. These data provide evidence that geometric manipulation of a ligand via biomaterials may enable more efficient and tunable programming of cellular signaling networks for therapeutic benefit in a variety of disease states, including autoimmunity and organ rejection, and thus should be an active area of further research.

Rapid and Persistent Delivery of Antigen by Lymph Node Targeting PRINT Nanoparticle Vaccine Carrier To Promote Humoral Immunity

Nanoparticle delivery of subunit vaccines may increase vaccine efficacy, leading to a wide variety of safe and effective vaccines beyond those available through dosing inactivated or live, attenuated whole pathogens. Here we present a versatile vaccine delivery platform based on PRINT hydrogels made of biocompatible hydroxy-poly(ethylene glycol) (PEG) that is able to activate the complement system by the alternative pathway. These lymph node targeting nanoparticles (NPs) promote the immunogenicity of a model antigen, ovalbumin, showing comparable adjuvant effect to alum. We demonstrate that an antigen-specific humoral response is correlated with antigen delivery to the draining lymph nodes, in particular, B cell rich regions of the lymph nodes. 80 × 180 nm cylindrical NPs were able to sustain prolonged antigen presentation to antigen presenting cells (APCs) and elicit a stronger immune response than nondraining 1 × 1 μm NPs or rapidly clearing soluble antigen. The 80 × 180 nm NPs also show high levels of uptake by key APCs and efficiently stimulate CD4(+) helper T cell proliferation in vivo, further promoting antibody production. These features together produce a significant humoral immune response, superior to that produced by free antigen alone. The simplicity of the chemistries used in antigen conjugation to PRINT NPs confers versatility to this antigen delivery platform, allowing for potential application to many infectious diseases.