Delivery Vectors Research Articles

Assessment of Adipocyte Transduction Using Different AAV Capsid Variants.

Adeno-associated viruses (AAVs) are widely used as viral vectors for gene delivery in mammalian cells. We focused on the efficacy of the transduction of AAV2/5, 2/6, 2/8 and 2/9 expressing GFP in preadipocyte cells by live imaging microscopy using IncuCyte S3 and flow cytometry. Three transduction modes in 3T3-L1 preadipocyte cells assessed: AAV transduction in 3T3-L1 preadipocyte cells, transduction with further differentiation into mature adipocyte-like cells and the transduction of differentiated 3T3-L1 adipocytes. For the in vivo study, we injected AAV2/6, AAV2/8 and AAV2/9 in adipose tissue of C57BL6 mice, and the transduction capacity of AAV2/6, along with AAV2/8 and AAV2/9 was evaluated. AAV2/6 demonstrated the highest transduction efficiency in 3T3-L1 preadipocytes, as it was 1.5-2-fold more effective than AAV2/5, and AAV2/8 in the range of viral concentrations from 2 × 104 to 1.6 × 105 VG/cell. AAV2/5 and AAV2/8 showed transduction efficiencies similar to each other. The expression of GFP under the CMV promoter remained stable for up to 20 days. The induction of 3T3-L1 differentiation in three days after AAV transduction did not alter the GFP expression level, and AAV2/6 showed the best transduction efficiency. AAV2/6 demonstrated the ability to transduce mature adipocytes. These results were confirmed by in vivo studies on C57BL6 mice. AAV2/6 had the highest transducing activity on both inguinal and interscapular adipose tissue. Thus, AAV2/6 has demonstrated higher transduction efficacy compared to AAV2/5, AAV2/8 and AAV2/9 both in 3T3-L1 adipocytes and adipose tissue in vivo, which proves its usability along with AAV2/8 and AAV2/9 for gene delivery to adipocytes.

Polymers as Efficient Non-Viral Gene Delivery Vectors: The Role of the Chemical and Physical Architecture of Macromolecules.

Gene therapy is the technique of inserting foreign genetic elements into host cells to achieve a therapeutic effect. Although gene therapy was initially formulated as a potential remedy for specific genetic problems, it currently offers solutions for many diseases with varying inheritance patterns and acquired diseases. There are two major groups of vectors for gene therapy: viral vector gene therapy and non-viral vector gene therapy. This review examines the role of a macromolecule's chemical and physical architecture in non-viral gene delivery, including their design and synthesis. Polymers can boost circulation, improve delivery, and control cargo release through various methods. The prominent examples discussed include poly-L-lysine, polyethyleneimine, comb polymers, brush polymers, and star polymers, as well as hydrogels and natural polymers and their modifications. While significant progress has been made, challenges still exist in gene stabilization, targeting specificity, and cellular uptake. Overcoming cytotoxicity, improving delivery efficiency, and utilizing natural polymers and hybrid systems are vital factors for prospects. This comprehensive review provides an illuminating overview of the field, guiding the way toward innovative non-viral-based gene delivery solutions.

A nanobody interaction with SARS-COV-2 Spike allows the versatile targeting of lentivirus vectors.

While investigating methods to target gene delivery vectors to specific cell types, we examined the potential of using a nanobody against the SARS-CoV-2 Spike protein receptor-binding domain to direct lentivirus infection of Spike-expressing cells. Using four different approaches, we found that lentiviruses with surface-exposed nanobody domains selectively infect Spike-expressing cells. Targeting is dependent on the fusion function of the Spike protein, and conforms to a model in which nanobody binding to the Spike protein triggers the Spike fusion machinery. The nanobody-Spike interaction also is capable of directing cell-cell fusion and the selective infection of nanobody-expressing cells by Spike-pseudotyped lentivirus vectors. Significantly, cells infected with SARS-CoV-2 are efficiently and selectively infected by lentivirus vectors pseudotyped with a chimeric nanobody protein. Our results suggest that cells infected by any virus that forms syncytia may be targeted for gene delivery by using an appropriate nanobody or virus receptor mimic. Vectors modified in this fashion may prove useful in the delivery of immunomodulators to infected foci to mitigate the effects of viral infections.IMPORTANCEWe have discovered that lentiviruses decorated on their surfaces with a nanobody against the SARS-CoV-2 Spike protein selectively infect Spike-expressing cells. Infection is dependent on the specificity of the nanobody and the fusion function of the Spike protein and conforms to a reverse fusion model, in which nanobody binding to Spike triggers the Spike fusion machinery. The nanobody-Spike interaction also can drive cell-cell fusion and infection of nanobody-expressing cells with viruses carrying the Spike protein. Importantly, cells infected with SARS-CoV-2 are selectively infected with nanobody-decorated lentiviruses. These results suggest that cells infected by any virus that expresses an active receptor-binding fusion protein may be targeted by vectors for delivery of cargoes to mitigate infections.

C-di-GMP@ZIF-8 nanocomposite injectable hydrogel based on modified chitosan and hyaluronic acid for infected wound healing by activating STING signaling

The treatment of infected wounds relies on antibiotics; however, increasing drug resistance has made therapeutic processes more difficult. Activating self-innate immune abilities may provide a promising alternative to treat wounds with bacterial infections. In this work, we constructed an immunogenic injectable hydrogel crosslinked by the Schiff base reaction of carboxymethyl chitosan (NOCC) and aldehyde hyaluronic acid (AHA) and encapsulated with stimulator of interferon genes (STING) agonist c-di-GMP loaded ZIF-8 nanoparticles (c-di-GMP@ZIF-8). Nanocubic ZIF-8 was screened as the most efficient intracellular drug delivery vector from five differently-shaped morphologies. The NOCC/AHA hydrogel released c-di-GMP@ZIF-8 more quickly (43 %) in acidic environment (pH = 5.5) of infected wounds compared with 34 % in non-infected wound environment (pH = 7.4) at 96 h due to pH-responsive degradation performance. The released c-di-GMP@ZIF-8 was found to activate the STING signaling of macrophages and enhance the secretion of IFN-β, CCL2, and CXCL12 5.8–7.6 times compared with phosphate buffer saline control, which effectively inhibited S. aureus growth and promoted fibroblast migration. In rat models with infected wounds, the c-di-GMP@ZIF-8 nanocomposite hydrogels improved infected wound healing by promoting granulation tissue regeneration, alleviating S. aureus-induced inflammation, and improving angiogenesis. Altogether, this study demonstrated a feasible strategy using STING-targeted and pH-responsive hydrogels for infected wound management.

The cardiac toxicity of PAMAM dendrimer drug delivery systems can be attenuated with the adjunct use of cardioprotective agents.

Polyamidoamine (PAMAM) dendrimer nanoparticles are efficient drug delivery vectors with potential clinical applications in nanomedicine. However, PAMAMs can compromise heart function, and strategies to mitigate cardiotoxicity would be beneficial. In this study, we investigated whether the adjunct use of three key cardioprotective agents could prevent the cardiac injury induced by a seventh-generation cationic PAMAM dendrimer (G7). Isolated rat hearts were subjected to ischemia and reperfusion (I/R) injury in the presence or absence of G7 or the cardioprotective agents Losartan, Epidermal Growth Factor (EGF), or S-nitroso-N-acetylpenicillamine (SNAP). I/R injury significantly compromised cardiac function, in terms of left ventricular hemodynamics, contractility, and vascular dynamics, which were markedly improved (p<0.05) by the administration of Losartan, EGF, or SNAP alone, confirming their cardioprotective effects. The administration of G7 significantly worsened cardiac function recovery following I/R(p<0.05). G7-induced impairments in cardiac and vascular dynamics were significantly improved by co-administration of Losartan, EGF, or SNAP. Treatment with G7 also significantly increased cardiac enzyme levels and infarct size, both of which were markedly reduced upon co-infusion of Losartan, EGF, or SNAP (p<0.05). Thus, G7 deteriorates the recovery of cardiac function in isolated hearts subjected to I/R injury, which can be rescued by co-administration of Losartan, EGF, or SNAP. These findings enhance our understanding of the nanotoxicology of PAMAM dendrimers in the mammalian heart and suggest that the adjunct use of cardioprotective agents is an effective strategy for mitigating the cardiotoxicity of these dendrimers and potentially other drug delivery systems.

Advances in Nanoparticles as Non-Viral Vectors for Efficient Delivery of CRISPR/Cas9.

The clustered regularly interspaced short palindromic repeat (CRISPR)/Cas9 system is a gene-editing technology. Nanoparticle delivery systems have attracted attention because of the limitations of conventional viral vectors. In this review, we assess the efficiency of various nanoparticles, including lipid-based, polymer-based, inorganic, and extracellular vesicle-based systems, as non-viral vectors for CRISPR/Cas9 delivery. We discuss their advantages, limitations, and current challenges. By summarizing recent advancements and highlighting key strategies, this review aims to provide a comprehensive overview of the role of non-viral delivery systems in advancing CRISPR/Cas9 technology for clinical applications and gene therapy.

A Comprehensive Review on Phage Therapy and Phage-Based Drug Development.

Phage therapy, the use of bacteriophages (phages) to treat bacterial infections, is regaining momentum as a promising weapon against the rising threat of multidrug-resistant (MDR) bacteria. This comprehensive review explores the historical context, the modern resurgence of phage therapy, and phage-facilitated advancements in medical and technological fields. It details the mechanisms of action and applications of phages in treating MDR bacterial infections, particularly those associated with biofilms and intracellular pathogens. The review further highlights innovative uses of phages in vaccine development, cancer therapy, and as gene delivery vectors. Despite its targeted and efficient approach, phage therapy faces challenges related to phage stability, immune response, and regulatory approval. By examining these areas in detail, this review underscores the immense potential and remaining hurdles in integrating phage-based therapies into modern medical practices.

Hypoxia and Foxn1 alter the proteomic signature of dermal fibroblasts to redirect scarless wound healing to scar-forming skin wound healing in Foxn1−/− mice

BackgroundFoxn1−/− deficient mice are a rare model of regenerative skin wound healing among mammals. In wounded skin, the transcription factor Foxn1 interacting with hypoxia-regulated factors affects re-epithelialization, epithelial-mesenchymal transition (EMT) and dermal white adipose tissue (dWAT) reestablishment and is thus a factor regulating scar-forming/reparative healing. Here, we hypothesized that transcriptional crosstalk between Foxn1 and Hif-1α controls the switch from scarless (regenerative) to scar-present (reparative) skin wound healing. To verify this hypothesis, we examined (i) the effect of hypoxia/normoxia and Foxn1 signalling on the proteomic signature of Foxn1−/− (regenerative) dermal fibroblasts (DFs) and then (ii) explored the effect of Hif-1α or Foxn1/Hif-1α introduced by a lentiviral (LV) delivery vector to injured skin of regenerative Foxn1−/− mice with particular attention to the remodelling phase of healing.ResultsWe showed that hypoxic conditions and Foxn1 stimulation modified the proteome of Foxn1−/− DFs. Hypoxic conditions upregulated DF protein profiles, particularly those related to extracellular matrix (ECM) composition: plasminogen activator inhibitor-1 (Pai-1), Sdc4, Plod2, Plod1, Lox, Loxl2, Itga2, Vldlr, Ftl1, Vegfa, Hmox1, Fth1, and F3. We found that Pai-1 was stimulated by hypoxic conditions in regenerative Foxn1−/− DFs but was released by DFs to the culture media exclusively upon hypoxia and Foxn1 stimulation. We also found higher levels of Pai-1 protein in DFs isolated from Foxn1+/+ mice (reparative/scar-forming) than in DFs isolated from Foxn1−/− (regenerative/scarless) mice and triggered by injury increase in Foxn1 and Pai-1 protein in the skin of mice with active Foxn1 (Foxn1+/+ mice). Then, we demonstrated that the introduction of Foxn1 and Hif-1α via lentiviral injection into the wounded skin of regenerative Foxn1−/− mice activates reparative/scar-forming healing by increasing the wounded skin area and decreasing hyaluronic acid deposition and the collagen type III to I ratio. We also identified a stimulatory effect of LV-Foxn1 + LV-Hif-1α injection in the wounded skin of Foxn1−/− mice on Pai-1 protein levels.ConclusionsThe present data highlight the effect of hypoxia and Foxn1 on the protein profile and functionality of regenerative Foxn1−/− DFs and demonstrate that the introduction of Foxn1 and Hif-1α into the wounded skin of regenerative Foxn1−/− mice activates reparative/scar-forming healing.

Interim safety and efficacy of gene therapy for RLBP1-associated retinal dystrophy: a phase 1/2 trial

Gene therapy holds promise for treatment of inherited retinal dystrophies, a group of rare genetic disorders characterized by severe loss of vision. Here, we report up to 3-year pre-specified interim safety and efficacy results of an open-label first-in-human dose-escalation phase 1/2 gene therapy clinical trial in 12 patients with retinal dystrophy caused by biallelic mutations in the retinaldehyde-binding protein 1 (RLBP1) gene of the visual cycle. The primary endpoints were systemic and ocular safety and recovery of dark adaptation. Secondary endpoints included microperimetry, visual field sensitivity, dominant eye test and patient-reported outcomes. Subretinal delivery of an adeno-associated viral vector (AAV8-RLBP1) was well tolerated with dose-dependent intraocular inflammation which responded to corticosteroid treatment, and focal atrophy of the retinal pigment epithelium as the dose limiting toxicity. Dark adaptation kinetics, the primary efficacy endpoint, improved significantly in all dose-cohorts. Treatment with AAV8-RLBP1 resulted in the resolution of disease-related retinal deposits, suggestive of successful restoration of the visual cycle. In conclusion, to date, AAV8-RLBP1 has shown preliminary safety and efficacy in patients with RLBP1-associated retinal dystrophy. Trial number: NCT03374657.

Limb Perfusion Delivery of a rAAV1 Alpha-1 Antitrypsin Vector in Non-Human Primates Is Safe but Insufficient for Therapy.

α-1 antitrypsin (AAT) deficiency is an inherited, genetic condition characterized by reduced serum levels of AAT and increased risk of developing emphysema and liver disease. AAT is normally synthesized primarily in the liver, but muscle-targeting with a recombinant adeno-associated virus (rAAV) vector for α-1 antitrypsin (AAT) gene therapy has been used to minimize liver exposure to the virus and hepatotoxicity. Clinical trials of direct intramuscular (IM) administration of rAAV1-hAAT have demonstrated its overall safety and transgene expression for 5 years. However, the failure to reach the therapeutic target level after 100 large-volume (1.5 mL) IM injections of maximally concentrated vector led us to pursue a muscle-targeting approach using isolated limb perfusion. This targets the rAAV to a greater muscle mass and allows for a higher total volume (and thereby a higher dose) than is tolerable by multiple direct IM injections. Limb perfusion has been shown to be feasible in non-human primates using the rAAV1 serotype and a ubiquitous promoter expressing an epitope-tagged AAT matched to the host species. In this study, we performed a biodistribution and preclinical safety study in non-human primates with a clinical candidate rAAV1-human AAT (hAAT) vector at doses ranging from 3.0 × 1012 to 1.3 × 1013 vg/kg, bracketing those used in our clinical trials. We found that limb perfusion delivery of rAAV1-hAAT was safe and showed a biodistribution pattern similar to previous studies. However, serum levels of AAT obtained with high-dose limb perfusion still reached only ~50% of the target serum levels. Our results suggest that clinically effective AAT gene therapy may ultimately require delivery at doses between 3.5 × 1013-1 × 1014 vg/kg, which is within the dose range used for approved rAAV gene therapies. Muscle-targeting strategies could be incorporated when delivering systemic administration of high-dose rAAV gene therapies to increase transduction of muscle tissues and reduce the burden on the liver, especially in diseases that can present with hepatotoxicity such as AAT deficiency.

Temperature Sensitive PNIPAm-g-PEI/Gold Nanotriangle for Gene Delivery Promotion.

As a two-dimensional material, gold nanotriangles (GNTs) are rarely studied in the field of gene delivery. In this study, a temperature-responsive GNTs was developed as a novel carrier for gene delivery. The temperature-sensitive copolymer PNIPAm-g-PEI was grafted onto the surface of GNTs to construct a PNIPAm-g-PEI/GNTs composite controllable release platform. The lower critical solution temperature (LCST) of PNIPAm-g-PEI/GNTs was found to be 42°C, and the particle size of PNIPAm-g-PEI/GNTs was 150nm at this temperature. Gel electrophoresis experiments showed that PNIPAm-g-PEI/GNTs completely condensed DNA at 20μg/mL, and PNIPAm-g-PEI/GNTs promoted the release of DNA under laser irradiation. Luciferase and green fluorescent protein reporter gene assays demonstrated that the transfection efficiency of PNIPAm-g-PEI/GNTs was 1.5 and 7.2 times that of PEI, respectively. These results demonstrated the promising potential of temperature-responsive GNTs as effective and safe gene delivery vectors.

Human cell surface-AAV interactomes identify LRP6 as blood-brain barrier transcytosis receptor and immune cytokine IL3 as AAV9 binder

Adeno-associated viruses (AAVs) are foundational gene delivery tools for basic science and clinical therapeutics. However, lack of mechanistic insight, especially for engineered vectors created by directed evolution, can hamper their application. Here, we adapt an unbiased human cell microarray platform to determine the extracellular and cell surface interactomes of natural and engineered AAVs. We identify a naturally-evolved and serotype-specific interaction between the AAV9 capsid and human interleukin 3 (IL3), with possible roles in host immune modulation, as well as lab-evolved low-density lipoprotein receptor-related protein 6 (LRP6) interactions specific to engineered capsids with enhanced blood-brain barrier crossing in non-human primates after intravenous administration. The unbiased cell microarray screening approach also allows us to identify off-target tissue binding interactions of engineered brain-enriched AAV capsids that may inform vectors’ peripheral organ tropism and side effects. Our cryo-electron tomography and AlphaFold modeling of capsid-interactor complexes reveal LRP6 and IL3 binding sites. These results allow confident application of engineered AAVs in diverse organisms and unlock future target-informed engineering of improved viral and non-viral vectors for non-invasive therapeutic delivery to the brain.

Acidified sucralfate encapsulated chitosan derivative nanoparticles as oral vaccine adjuvant delivery enhancing mucosal and systemic immunity

Oral vaccines are generally perceived to be safe, easy to administer, and have the potential to induce both systemic and mucosal immune responses. However, given the challenges posed by the harsh gastrointestinal environment and mucus barriers, the development of oral vaccines necessitates the employment of a safe and efficient delivery system. In recent years, nanoparticle-based delivery has proven to be an ideal delivery vector for the manufacture of oral vaccines. Hence, considering the above, the sucralfate acidified (SA) encapsulated N-2-Hydroxypropyl trimethyl ammonium chloride chitosan (N-2-HACC)/N,O-carboxymethyl chitosan (CMCS) nanoparticles (SA@N-2-HACC/CMCS NPs) were prepared, and the BSA was used as a model antigen to investigate the immune responses. The SA@N-2-HACC/CMCS NPs had a particle size of 227 ± 7.0 nm and a zeta potential of 8.43 ± 2.62 mV. The NPs displayed slow and sustained release and high stability in simulated gastric juice and intestinal fluid. RAW 264.7 macrophage-like cell line demonstrated enhanced uptake of the SA@N-2-HACC/CMCS/BSA Nps. The vaccine via oral administration markedly enhanced the residence time of BSA in the intestine for more than 12 h and elicited the production of IgG and sIgA. The SA@N-2-HACC/CMCS NPs developed here for oral administration is an excellent technique for delivering antigens and provides a path of mucosal vaccine research.

EXTL3 and NPC1 are mammalian host factors for Autographa californica multiple nucleopolyhedrovirus infection

Baculovirus is an obligate parasitic virus of the phylum Arthropoda. Baculovirus including Autographa californica multiple nucleopolyhedrovirus (AcMNPV) has been widely used in the laboratory and industrial preparation of proteins or protein complexes. Due to its large packaging capacity and non-replicative and non-integrative natures in mammals, baculovirus has been proposed as a gene therapy vector for transgene delivery. However, the mechanism of baculovirus transduction in mammalian cells has not been fully illustrated. Here, we employed a cell surface protein-focused CRISPR screen to identify host dependency factors for baculovirus transduction in mammalian cells. The screening experiment uncovered a series of baculovirus host factors in human cells, including exostosin-like glycosyltransferase 3 (EXTL3) and NPC intracellular cholesterol transporter 1 (NPC1). Further investigation illustrated that EXTL3 affected baculovirus attachment and entry by participating in heparan sulfate biosynthesis. In addition, NPC1 promoted baculovirus transduction by mediating membrane fusion and endosomal escape. Moreover, in vivo, baculovirus transduction in Npc1−/+ mice showed that disruption of Npc1 gene significantly reduced baculovirus transduction in mouse liver. In summary, our study revealed the functions of EXTL3 and NPC1 in baculovirus attachment, entry, and endosomal escape in mammalian cells, which is useful for understanding baculovirus transduction in human cells.

Recent Advances in Therapeutics and Manufacturing Processes of Recombinant Adeno-Associated Virus for the Treatment of Lung Diseases.

Developing delivery vectors capable of transducing genetic material across the lung epithelia and mucus barrier is a major challenge and of great interest to enable gene therapies to treat pulmonary diseases. Recombinant Adeno-associated Viruses (rAAVs) have emerged as attractive candidates among viral and non-viral vectors due to their broad tissue tropism, ability to transduce dividing and quiescent cells, and their safety profile in current human applications. While rAAVs have demonstrated safety in earlier clinical trials for lung disease applications, there are still some limitations regarding rAAV-transgene delivery in pulmonary cells. Thus, further improvements in rAAV engineering are needed to enhance the effectiveness of rAAV-based therapies for lung diseases. Such therapies could benefit patients with chronic lung diseases, such as asthma, chronic obstructive pulmonary disease, pulmonary hypertension, and cystic fibrosis, among others, by regulating hereditary gene mutations or acquired gene deregulations causing these conditions. Alongside therapeutic development, advances in the rAAV production process are essential to meet increasing production demands, while reducing manufacturing costs. This review discusses current challenges and recent advances in the field of rAAV engineering and manufacturing to encourage the clinical development of new pulmonary gene therapy treatments.

Potential applications of PEI loaded graphene oxide quantum dots in safe and efficient DNA delivery

In order to improve the safety and efficacy of gene delivery using polyethyleneimine (PEI), this work focused on developing PEI quantum dots and incorporating them onto graphene to improve gene loading capacity. The successful creation of graphene-polyethyleneimine quantum dots (GPQDs) was confirmed through fluorescence emission spectrum and infrared spectroscopy. Both polyethyleneimine quantum dots (PQDs) and GPQDs exhibited blue fluorescence when excited between 310 and 430 nm, indicating that they retained the fluorescence characteristics of broad excitation and narrow emission. Furthermore, GPQDs displayed smaller particle sizes, increased hydrophilicity, and better dispersibility compared to PQDs. GPQDs were able to efficiently load DNA with lower cytotoxicity than PQDs and PEI. The enhanced fluorescence properties of GPQDs allowed for the observation that GPQDs/DNA complexes were effectively internalized by cells with higher uptake efficiency than PEI/DNA and PQDs/DNA complexes. The study demonstrated that GPQDs/DNA complexes successfully transfected 293T and HeLa cells, with GPQDs prepared using PEI25k showing improved cell uptake and transfection efficiency compared to those prepared with PEI10k. Overall, the findings suggest that GPQDs are a more effective and safer gene delivery vector than PEI, with promising potential for future gene delivery applications.

Strategies for Organ-Targeted mRNA Delivery by LipidNanoparticles.

Messenger RNA (mRNA) technology has rapidly evolved, significantly impacting various therapeutic applications, including vaccines, protein replacement, and gene editing. Lipid nanoparticles (LNPs) have emerged as a pivotal nonviral vector for mRNA delivery, crucial for organ-targeted therapies. Despite their success, most LNP formulations predominantly target the liver, limiting their use in nonliver diseases. This review explores strategies to achieve organ-specific mRNA delivery using LNPs, including the discovery of new lipid structures, modification of targeting ligands, incorporation of additional components, and optimization of LNP formulations. These advancements aim to enhance the precision and efficacy of mRNA therapeutics across a broader range of diseases.

Tetrahedral framework nucleic acid-based small-molecule inhibitor delivery for ecological prevention of biofilm.

Biofilm formation constitutes the primary cause of various chronic infections, such as wound infections, gastrointestinal inflammation and dental caries. While preliminary achievement of biofilm inhibition is possible, the challenge lies in the difficulty of eliminating the bactericidal effects of current drugs that lead to microbiota imbalance. This study, utilizing in vitro and in vivo models of dental caries, aims to efficiently inhibit biofilm formation without inducing bactericidal effects, even against pathogenic bacteria. The tetrahedral framework nucleic acid (tFNA) was employed as a delivery vector for a small-molecule inhibitor (smI) specifically targeting the activity of glucosyltransferases C (GtfC). It was observed that tFNA loaded smI in a small-groove binding manner, efficiently transferring it into Streptococcus mutans, thereby inhibiting GtfC activity and extracellular polymeric substances formation without compromising bacterial survival. Furthermore, smI-loaded tFNA demonstrated a reduction in the severity of dental caries in vivo without adversely affecting oral microbial diversity and exhibited desirable topical and systemic biosafety. This study emphasizes the concept of 'ecological prevention of biofilm', which is anticipated to advance the optimization of biofilm prevention strategies and the clinical application of DNA nanocarrier-based drug formulations.

Immunogenicity risk assessment of empty capsids present in adeno-associated viral vectors using predictive innate immune responses

Immunogenicity of gene therapy and the impacts on safety and efficacy are of increasing interest in the pharmaceutical industry. Unique structural aspects of gene therapy delivery vectors, such as adeno-associated viral (AAV) vectors, are expected to activate the innate immune system. The risk of innate immune activation is critical to understand due to the potential impacts on safety and on subsequent adaptive immune responses. In this study, we investigated the responses of key innate immune players—dendritic cells, natural killer (NK) cells, and the complement system—to AAV8 capsids. Immunogenicity risk was also predicted in the presence empty AAV capsids for AAV gene therapy. Compared to genome-containing "full" AAV8 capsids, empty AAV8 capsids more strongly induced proinflammatory cytokine production and migration by human and mouse dendritic cells, but the “full” capsid increased expression of co-stimulatory markers. Furthermore, in an NK cell degranulation assay, we found mixtures of empty and full AAV8 capsids to activate expression of TNF-α, IFN-γ, and CD107a more strongly in multiple NK cell populations compared to either capsid type alone. Serum complement C3a was also induced more strongly in the presence of mixed empty and full AAV8 capsid formulations. Risk for innate immune activation suggests the importance to determine acceptable limits of empty capsids. Immunogenicity risk assessment of novel biological modalities will benefit from the aforementioned in vitro innate immune activation assays providing valuable mechanistic information.

Secreted Particle Information Transfer (SPIT) - A Cellular Platform for In Vivo Genetic Engineering.

A multitude of tools now exist that allow us to precisely manipulate the human genome in a myriad of different ways. However, successful delivery of these tools to the cells of human patients remains a major barrier to their clinical implementation. Here we introduce a new cellular approach for in vivo genetic engineering, Secreted Particle Information Transfer (SPIT) that utilizes human cells as delivery vectors for in vivo genetic engineering. We demonstrate the application of SPIT for cell-cell delivery of Cre recombinase and CRISPR-Cas9 enzymes, we show that genetic logic can be incorporated into SPIT and present the first demonstration of human cells as a delivery platform for in vivo genetic engineering in immunocompetent mice. We successfully applied SPIT to genetically modify multiple organs and tissue stem cells in vivo including the liver, spleen, intestines, peripheral blood, and bone marrow. We anticipate that by harnessing the large packaging capacity of a human cell's nucleus, the ability of human cells to engraft into patients' long term and the capacity of human cells for complex genetic programming, that SPIT will become a paradigm shifting approach for in vivo genetic engineering.