Developing Biodegradable Lipid Nanoparticles for Intracellular mRNA Delivery and Genome Editing

Potential nanocarrier-mediated miRNA-based therapy approaches for multiple sclerosis

Multiple sclerosis (MS) is an autoimmune neuroinflammatory disorder attributed to neurodegeneration and demyelination, resulting in neurological impairment. miRNA has a significant role in biological processes in MS. In this review, we focus on the feasibility of delivering miRNAs through nanoformulations for managing MS. We provide a brief discussion of miRNA synthesis and evidence for miRNA dysregulation in MS. We also highlight formulation strategies and resulting technologies for the effective delivery of miRNAs through nanocarrier systems for achieving high therapeutic benefits.

Narrative review on century of respiratory pandemics from Spanish flu to COVID-19 and impact of nanotechnology on COVID-19 diagnosis and immune system boosting

The rise of the highly lethal severe acute respiratory syndrome-2 (SARS-2) as corona virus 2019 (COVID-19) reminded us of the history of other pandemics that happened in the last century (Spanish flu) and stayed in the current century, which include Severe-Acute-Respiratory-Syndrome (SARS), Middle-East-Respiratory-Syndrome (MERS), Corona Virus 2019 (COVID-19). We review in this report the newest findings and data on the origin of pandemic respiratory viral diseases, reservoirs, and transmission modes. We analyzed viral adaption needed for host switch and determinants of pathogenicity, causative factors of pandemic viruses, and symptoms and clinical manifestations. After that, we concluded the host factors associated with pandemics morbidity and mortality (immune responses and immunopathology, ages, and effect of pandemics on pregnancy). Additionally, we focused on the burdens of COVID-19, non-pharmaceutical interventions (quarantine, mass gatherings, facemasks, and hygiene), and medical interventions (antiviral therapies and vaccines). Finally, we investigated the nanotechnology between COVID-19 analysis and immune system boosting (Nanoparticles (NPs), antimicrobial NPs as antivirals and immune cytokines). This review presents insights about using nanomaterials to treat COVID-19, improve the bioavailability of the abused drugs, diminish their toxicity, and improve their performance.

How far are the new wave of mRNA drugs from us? mRNA product current perspective and future development

mRNA products are therapies that are regulated from the post-transcriptional, pre-translational stage of a gene and act upstream of protein synthesis. Compared with traditional small molecule drugs and antibody drugs, mRNA drugs had the advantages of simple design, short development cycle, strong target specificity, wide therapeutic field, and long-lasting effect. mRNA drugs were now widely used in the treatment of genetic diseases, tumors, and viral infections, and are expected to become the third major class of drugs after small molecule drugs and antibody drugs. The delivery system technology was the key to ensuring the efficacy and safety of mRNA drugs, which plays an important role in protecting RNA structure, enhancing targeting ability, reducing the dose of drug delivery, and reducing toxic side effects. Lipid nanoparticles (LNP) were the most common delivery system for mRNA drugs. In recent years, mRNA drugs have seen rapid development, with the number of drugs on the market increasing each year. The success of commercializing mRNA vaccines has driven a wave of nucleic acid drug development. mRNA drugs were clinically used in genetic diseases, oncology, and infectious diseases worldwide, while domestic mRNA clinical development was focused on COVID-19 vaccines, with more scope for future indication expansion.

Nanocarriers: A novel strategy for the delivery of CRISPR/Cas systems

In recent decades, clustered regularly interspaced short palindromic repeat/CRISPR-associated protein (CRISPR/Cas) has become one of the most promising genome-editing tools for therapeutic purposes in biomedical and medical applications. Although the CRISPR/Cas system has truly revolutionized the era of genome editing, the safe and effective delivery of CRISPR/Cas systems represents a substantial challenge that must be tackled to enable the next generation of genetic therapies. In addition, there are some challenges in the in vivo delivery to the targeted cells/tissues. Nanotechnology-based drug delivery systems can be employed to overcome this issue. This review discusses different types and forms of CRISPR/Cas systems and the current CRISPR/Cas delivery systems, including non-viral carriers such as liposomes, polymeric, and gold particles. The focus then turns to the viral nanocarriers which have been recently used as a nanocarrier for CRISPR/Cas delivery.

Tailoring combinatorial lipid nanoparticles for intracellular delivery of nucleic acids, proteins, and drugs

Lipid nanoparticle (LNP)-based drug delivery systems have become the most clinically advanced non-viral delivery technology. LNPs can encapsulate and deliver a wide variety of bioactive agents, including the small molecule drugs, proteins and peptides, and nucleic acids. However, as the physicochemical properties of small- and macromolecular cargos can vary drastically, every LNP carrier system needs to be carefully tailored in order to deliver the cargo molecules in a safe and efficient manner. Our group applied the combinatorial library synthesis approach and in vitro and in vivo screening strategy for the development of LNP delivery systems for drug delivery. In this Review, we highlight our recent progress in the design, synthesis, characterization, evaluation, and optimization of combinatorial LNPs with novel structures and properties for the delivery of small- and macromolecular therapeutics both in vitro and in vivo. These delivery systems have enormous potentials for cancer therapy, antimicrobial applications, gene silencing, genome editing, and more. We also discuss the key challenges to the mechanistic study and clinical translation of new LNP-enabled therapeutics.

R848 Adjuvant Laden With Self-Assembled Nanoparticle-Based mRNA Vaccine Elicits Protective Immunity Against H5N1 in Mice

In order to perfect the design strategy of messenger RNA (mRNA) vaccines against the H5N1 influenza virus, we investigated whether different antigen designs and the use of adjuvants could improve the immune effect of mRNA vaccines. We designed three different forms of antigen genes, including Flu [H1/H3/H5/B-HA2(aa90~105)-M2e(24aa)], Flu-Fe (Fe, ferritin), and CD5-Flu-Fe (CD5, a secretion signal peptide). Meanwhile, R848 (Requimod) was selected as the adjuvant of the mRNA vaccine. We prepared cationic lipid nanoparticles for mRNA delivery, named LNP-Man (mannose-modified lipid nanoparticles). Cell transfection results showed that Flu-Fe/CD5-Flu-Fe containing ferritin could express the target antigens HA2 and M2e more efficiently than Flu. In the mice immune experiment, five immune groups (LNP-Man/Flu, LNP-Man/Flu-Fe, LNP-Man/CD5-Flu-Fe, LNP-Man/Flu-Fe+R848, and LNP-Man/CD5-Flu-Fe+R848) and two control groups (LNP-Man, PBS) were set up. After being infected with the 1×LD50 H5N1 avian influenza virus, the survival rate of the mice in the LNP-Man/CD5-Flu-Fe, LNP-Man/Flu-Fe+R848, and LNP-Man/CD5-Flu-Fe+R848 were 100%. More importantly, in LNP-Man/Flu-Fe+R848 and LNP-Man/CD5-Flu-Fe+R848 groups, there was no residual virus detected in the mice lung tissue on the 5th day postchallenge. Overall, this study provides a new idea for the design of H5N1 avian influenza virus mRNA vaccines in terms of antigen designs and adjuvant selection.

Endothelial cell-targeting, ROS-ultrasensitive drug/siRNA co-delivery nanocomplexes mitigate early-stage neutrophil recruitment for the anti-inflammatory treatment of myocardial ischemia reperfusion injury

Neutrophils serve as a key contributor to the pathophysiology of myocardial ischemia reperfusion injury (MIRI), because the unregulated activation and infiltration of neutrophils lead to overwhelming inflammation in the myocardium to cause tissue damage. Herein, endothelial cell-targeting and  reactive oxygen species (ROS)-ultrasensitive nanocomplexes (NCs) were developed to mediate efficient co-delivery of VCAM-1 siRNA (siVCAM-1) and dexamethasone (DXM), which cooperatively inhibited neutrophil recruitment by impeding neutrophil migration and adhesion. RPPT was first synthesized via crosslinking of PEI 600 with ditellurium followed by modification with PEG and the endothelial cell-targeting peptide cRGD. RPPT was allowed to envelope the DXM-loaded PLGA nanoparticles and condense the siVCAM-1. After systemic administration in rats experiencing MIRI, the cRGD-modified NCs efficiently targeted and entered the inflamed endothelial cells, wherein RPPT was sensitively degraded by over-produced ROS to trigger intracellular siVCAM-1 release and potentiate the VCAM-1 silencing efficiency. As a consequence of the complementary function of DXM and siVCAM-1, the NCs notably mitigated neutrophil infiltration into ischemic myocardium, provoking potent anti-inflammatory efficacy to reduce MIRI and recover cardiac function. The present study offers an effective approach for the controlled co-delivery of siRNA and drug cargoes, and it also highlights the importance of multi-dimensional manipulation of neutrophils in anti-inflammatory treatment. STATEMENT OF SIGNIFICANCE: The unregulated activation and infiltration of neutrophils lead to overwhelming inflammation in the myocardium after myocardial ischemia reperfusion injury (MIRI). Here, endothelial cell-targeting and ROS-ultrasensitive nanocomplexes (NCs), comprised of PLGA NPs decorated with cRGD-poly(ethylene glycol) (PEG)-modified, ditellurium-crosslinked PEI (RPPT), were developed to mediate efficient co-delivery of VCAM-1 siRNA (siVCAM-1) and dexamethasone (DXM). DXM and siVCAM-1 with complementary functions inhibited both the migration and adhesion of neutrophils, efficiently interventing the neutrophil recruitment and interrupting the self-amplified inflammation cascade in the injured myocardium. The molecular design of RPPT renders an effective example for constructing polymeric materials with high ROS sensitivity, and it resolves the critical dilemma related to polycation-mediated siRNA delivery, such as siRNA encapsulation versus release, and transfection efficiency versus toxicity.

Controllable Fabrication of Small-Size Holding Pipets for the Nondestructive Manipulation of Suspended Living Single Cells

The capture and manipulation of single cells are an important premise and basis for intracellular delivery, which provides abundant molecular and omics information for biomedical development. However, for intracellular delivery of cargos into/from small-size suspended living single cells, the capture methods are limited by the lack of small-size holding pipets, poor cell activity, and the low spatial accuracy of intracellular delivery. To solve these problems, a method for the controllable fabrication of small-size holding pipets was proposed. A simple, homemade microforge instrument including an imaging device was built to cut and melt the glass capillary tip by controlling the heat production of a nichrome wire. The controllable fabrication of small-size holding pipets was realized by observing the fabrication process in real time. Combined with an electroosmotic drive system and a micromanipulation system with high spatial resolution, the holding pipet achieved the active capture, movement, and sampling of suspended living single cells. Moreover, solid-phase microextraction was performed on captured single pheochromocytoma cells, and the extracted dopamine was successfully detected using an electrochemical method. The homemade microforge instrument overcame the limitations of traditional microforges, resulting in holding pipets that were sufficiently small for small-size suspended single living cells (5-30 μm). This proactive capture method overcame the shortcomings of existing methods to achieve the multiangle, high-precision manipulation of single cells, thereby allowing the intracellular delivery of small-size single cells in suspension with high spatiotemporal resolution.

Nonviral Delivery Systems of mRNA Vaccines for Cancer Gene Therapy

In recent years, the use of messenger RNA (mRNA) in the fields of gene therapy, immunotherapy, and stem cell biomedicine has received extensive attention. With the development of scientific technology, mRNA applications for tumor treatment have matured. Since the SARS-CoV-2 infection outbreak in 2019, the development of engineered mRNA and mRNA vaccines has accelerated rapidly. mRNA is easy to produce, scalable, modifiable, and not integrated into the host genome, showing tremendous potential for cancer gene therapy and immunotherapy when used in combination with traditional strategies. The core mechanism of mRNA therapy is vehicle-based delivery of in vitro transcribed mRNA (IVT mRNA), which is large, negatively charged, and easily degradable, into the cytoplasm and subsequent expression of the corresponding proteins. However, effectively delivering mRNA into cells and successfully activating the immune response are the keys to the clinical transformation of mRNA therapy. In this review, we focus on nonviral nanodelivery systems of mRNA vaccines used for cancer gene therapy and immunotherapy.

Engineering Optimal Vaccination Strategies: Effects of Physical Properties of the Delivery System on Functions

With rapid developments in medical science and technology, vaccinations have become the key to solving public health problems. Various diseases can be prevented by vaccinations, which mimic a disease by...