Modifying the Backbone Chemistry of PEG-Based Bottlebrush Block Copolymers for the Formation of Long-Circulating Nanoparticles.

Nanoparticle physicochemical properties have received great attention in optimizing the performance of nanoparticles for biomedical applications. For example, surface functionalization with small molecules or linear hydrophilic polymers is commonly used to tune the interaction of nanoparticles with proteins and cells. However, it is challenging to control the location of functional groups within the shell for conventional nanoparticles. Nanoparticle surfaces composed of shape-persistent bottlebrush polymers allow hierarchical control over the nanoparticle shell but the effect of the bottlebrush backbone on biological interactions is still unknown. The synthesis is reported of novel heterobifunctional poly(ethylene glycol) (PEG)-norbornene macromonomers modified with various small molecules to form bottlebrush polymers with different backbone chemistries. It is demonstrated that micellar nanoparticles composed of poly(lactic acid) (PLA)-PEG bottlebrush block copolymer (BBCP) with neutral and cationic backbone modifications exhibit significantly reduced cellular uptake compared to conventional unmodified BBCPs. Furthermore, the nanoparticles display long blood circulation half-lives of ≈22 hours and enhanced tumor accumulation in mice. Overall, this work sheds light on the importance of the bottlebrush polymer backbone and provides a strategy to improve the performance of nanoparticles in biomedical applications.

Superoxide Dismutase-Mimetic Polyphenol-Based Carbon Dots for Multimodal Bioimaging and Treatment of Atopic Dermatitis.

Polyphenols have been investigated for their potential to mitigate inflammation in the context of atopic dermatitis (AD). In this study, epigallocatechin-3-gallate (EGCG)-based carbon dots (EGCG@CDs) were developed to enhance transdermal penetration, reduce inflammation, recapitulate superoxide dismutase (SOD) activity, and provide antimicrobial effects for AD treatment. The water-soluble EGCG@CDs in a few nanometers size exhibit a negative zeta potential, making them suitable for effective transdermal penetration. The fluorescence properties, including an upconversion effect, make EGCG@CDs suitable imaging probes for both in vitro and in vivo applications. By mimicking the SOD enzyme, EGCG@CDs scavenge reactive oxygen species (ROS) and actively produce hydrogen peroxide through a highly catalytic capability toward the oxygen reduction reaction, resulting in the inhibition of bacterial growth. The enhanced antioxidant properties, high charge mobility, and various functional groups of EGCG@CDs prove effective in reducing intracellular ROS in an in vitro AD model. In the mouse AD model, EGCG@CDs incorporated into a hydrogel actively penetrated the epidermal layer, leading to ROS scavenging, reduced mast cell activation, and histological recovery of skin barriers. This research represents the versatile potential of EGCG@CDs in addressing AD and advancing tissue engineering.

Strategy to develop broadly effective multivalent COVID-19 vaccines against emerging variants based on Ad5/35 platform.

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Omicron strain has evolved into highly divergent variants with several sub-lineages. These newly emerging variants threaten the efficacy of available COVID-19 vaccines. To mitigate the occurrence of breakthrough infections and re-infections, and more importantly, to reduce the disease burden, it is essential to develop a strategy for producing updated multivalent vaccines that can provide broad neutralization against both currently circulating and emerging variants. We developed bivalent vaccine AdCLD-CoV19-1 BA.5/BA.2.75 and trivalent vaccines AdCLD-CoV19-1 XBB/BN.1/BQ.1.1 and AdCLD-CoV19-1 XBB.1.5/BN.1/BQ.1.1 using an Ad5/35 platform-based non-replicating recombinant adenoviral vector. We compared immune responses elicited by the monovalent and multivalent vaccines in mice and macaques. We found that the BA.5/BA.2.75 bivalent and the XBB/BN.1/BQ.1.1 and XBB.1.5/BN.1/BQ.1.1 trivalent vaccines exhibited improved cross-neutralization ability compared to their respective monovalent vaccines. These data suggest that the developed multivalent vaccines enhance immunity against circulating Omicron subvariants and effectively elicit neutralizing antibodies across a broad spectrum of SARS-CoV-2 variants.

Nanoscale Surface Topography of Polyethylene Glycol-Coated Nanoparticles Composed of Bottlebrush Block Copolymers Prolongs Systemic Circulation and Enhances Tumor Uptake.

Improving the performance of nanocarriers remains a major challenge in the clinical translation of nanomedicine. Efforts to optimize nanoparticle formulations typically rely on tuning the surface density and thickness of stealthy polymer coatings, such as poly(ethylene glycol) (PEG). Here, we show that modulating the surface topography of PEGylated nanoparticles using bottlebrush block copolymers (BBCPs) significantly enhances circulation and tumor accumulation, providing an alternative strategy to improve nanoparticle coatings. Specifically, nanoparticles with rough surface topography achieve high tumor cell uptake in vivo due to superior tumor extravasation and distribution compared to conventional smooth-surfaced nanoparticles based on linear block copolymers. Furthermore, surface topography profoundly impacts the interaction with serum proteins, resulting in the adsorption of fundamentally different proteins onto the surface of rough-surfaced nanoparticles formed from BBCPs. We envision that controlling the nanoparticle surface topography of PEGylated nanoparticles will enable the design of improved nanocarriers in various biomedical applications.

Boosting with variant-matched adenovirus-based vaccines promotes neutralizing antibody responses against SARS-CoV-2 Omicron sublineages in mice.

Global spread of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) Omicron subvariants, such as BA.4, BA.5 and XBB.1.5, has been leading the recent wave of coronavirus disease 2019 (COVID-19). Unique mutations in the spike proteins of these emerging Omicron subvariants caused immune evasion from the pre-existing protective immunity induced by vaccination or natural infection. Previously, we developed AdCLD-CoV19-1, a non-replicating recombinant adenoviral vector that encodes the receptor binding domain of the spike protein of the ancestral SARS-CoV-2 strain. Based on the same recombinant adenoviral vector platform, updated vaccines that cover unique mutations found in each Omicron subvariant, including BA.1, BA.2, BA.4.1 and BA.5, were constructed. Preclinical studies revealed that each updated vaccine as a booster shot following primary vaccination targeting the ancestral strain improved neutralizing antibody responses against the pseudovirus of its respective strain most effectively. Of note, boosting with a vaccine targeting the BA.1 or BA.2 Omicron subvariant was most effective in neutralization against the pseudovirus of the BA.2.75 strain, whereas BA.4.1/5-adapted booster shots were most effective in neutralization against the BQ.1, BQ1.1 and BF.7 strains. Therefore, it is imperative to develop a vaccination strategy that can cover the unique spike mutations of currently circulating Omicron subvariants in order to prevent the next wave of COVID-19.

The MYST Family Histone Acetyltransferase SasC Governs Diverse Biological Processes in Aspergillus fumigatus.

The conserved MYST proteins form the largest family of histone acetyltransferases (HATs) that acetylate lysines within the N-terminal tails of histone, enabling active gene transcription. Here, we have investigated the biological and regulatory functions of the MYST family HAT SasC in the opportunistic human pathogenic fungus Aspergillus fumigatus using a series of genetic, biochemical, pathogenic, and transcriptomic analyses. The deletion (Δ) of sasC results in a drastically reduced colony growth, asexual development, spore germination, response to stresses, and the fungal virulence. Genome-wide expression analyses have revealed that the ΔsasC mutant showed 2402 significant differentially expressed genes: 1147 upregulated and 1255 downregulated. The representative upregulated gene resulting from ΔsasC is hacA, predicted to encode a bZIP transcription factor, whereas the UV-endonuclease UVE-1 was significantly downregulated by ΔsasC. Furthermore, our Western blot analyses suggest that SasC likely catalyzes the acetylation of H3K9, K3K14, and H3K29 in A. fumigatus. In conclusion, SasC is associated with diverse biological processes and can be a potential target for controlling pathogenic fungi.

Intrathecal delivery of nanoparticle PARP inhibitor to the cerebrospinal fluid for the treatment of metastatic medulloblastoma.

The morbidity associated with pediatric medulloblastoma, in particular in patients who develop leptomeningeal metastases, remains high in the absence of effective therapies. Administration of substances directly into the cerebrospinal fluid (CSF) is one approach to circumvent the blood-brain barrier and focus delivery of drugs to the site of tumor. However, high rates of CSF turnover prevent adequate drug accumulation and lead to rapid systemic clearance and toxicity. Here, we show that PLA-HPG nanoparticles, made with a single-emulsion, solvent evaporation process, can encapsulate talazoparib, a PARP inhibitor (BMN-673). These degradable polymer nanoparticles improve the therapeutic index when delivered intrathecally and lead to sustained drug retention in the tumor as measured with PET imaging and fluorescence microscopy. We demonstrate that administration of these particles into the CSF, alone or in combination with systemically administered temozolomide, is a highly effective therapy for tumor regression and prevention of leptomeningeal spread in xenograft mouse models of medulloblastoma. These results provide a rationale for harnessing nanoparticles for the delivery of drugs limited by brain penetration and therapeutic index and demonstrate important advantages in tolerability and efficacy for encapsulated drugs delivered locoregionally.

Polymer nanoparticles deliver mRNA to the lung for mucosal vaccination.

An inhalable platform for messenger RNA (mRNA) therapeutics would enable minimally invasive and lung-targeted delivery for a host of pulmonary diseases. Development of lung-targeted mRNA therapeutics has been limited by poor transfection efficiency and risk of vehicle-induced pathology. Here, we report an inhalable polymer-based vehicle for delivery of therapeutic mRNAs to the lung. We optimized biodegradable poly(amine-co-ester) (PACE) polyplexes for mRNA delivery using end-group modifications and polyethylene glycol. These polyplexes achieved high transfection of mRNA throughout the lung, particularly in epithelial and antigen-presenting cells. We applied this technology to develop a mucosal vaccine for severe acute respiratory syndrome coronavirus 2 and found that intranasal vaccination with spike protein-encoding mRNA polyplexes induced potent cellular and humoral adaptive immunity and protected susceptible mice from lethal viral challenge. Together, these results demonstrate the translational potential of PACE polyplexes for therapeutic delivery of mRNA to the lungs.

Rational nanoparticle design: Optimization using insights from experiments and mathematical models.

Polymeric nanoparticles are highly tunable drug delivery systems that show promise in targeting therapeutics to specific sites within the body. Rational nanoparticle design can make use of mathematical models to organize and extend experimental data, allowing for optimization of nanoparticles for particular drug delivery applications. While rational nanoparticle design is attractive from the standpoint of improving therapy and reducing unnecessary experiments, it has yet to be fully realized. The difficulty lies in the complexity of nanoparticle structure and behavior, which is added to the complexity of the physiological mechanisms involved in nanoparticle distribution throughout the body. In this review, we discuss the most important aspects of rational design of polymeric nanoparticles. Ultimately, we conclude that many experimental datasets are required to fully model polymeric nanoparticle behavior at multiple scales. Further, we suggest ways to consider the limitations and uncertainty of experimental data in creating nanoparticle design optimization schema, which we call quantitative nanoparticle design frameworks.

Factors Affecting Success of New Drug Clinical Trials.

Clinical trials are an essential process in the development of new drugs. In spite of time-consuming processes and high costs, the overall success rate of clinical trials is only 7.9%, which is a high risk for biopharmaceutical companies. However, despite these huge risks, research on finding factors affecting clinical trials to overcome and manage to risks has been insufficient. Considering these characteristics of the pharmaceutical industry, this study investigated the factors affecting the success of sponsor-initiated clinical trials. The success factors investigated were categorized into four factors: quality of clinical trials, speed of clinical trials, relationship type, and communication. Logistic regression was performed to measure each factor by analyzing 24,295 cases of Phase 1 to 4 trials from ClinicalTrials.gov. Because of the analysis, the factors affecting the success of the clinical trials were varied according to each clinical phase and the drug types: New Molecular Entity (NME)/Biologics, and the success ratio in the quality variable affected the overall clinical trial phases. Additionally, the experience, speed, relationship type, and communication variables were also found to be statistically significant for the success of each phase and drug type.

Development Pattern of Medical Device Technology and Regulatory Evolution of Cataract Treatment.

To prevent regulation from becoming an obstacle to healthcare technological innovation, regulation should evolve as new healthcare technologies are developed. Although regulation is closely related to healthcare technology development, there are few studies that view healthcare technological advances from the multi-layered perspective of papers, patents, and clinical research and link this with regulatory evolution. Therefore, this study tried to develop a new method from a multi-layer perspective and draw regulatory implications based on it. This study applied this method to intraocular lens (IOLs) for cataract treatment and detected four major healthcare technologies and two recent healthcare technologies. Moreover, it discussed how current regulations evaluate these technologies. The findings provide implications for healthcare technological advances and the evolutionary direction of regulation through the example of IOLs for cataract treatment. This study contributes to the development of theoretical methods for co-evolution with regulations based on healthcare technology innovation.

Association of Dual Sensory Impairment with Declining Physical Function in Community-Dwelling Older Adults.

Few studies have investigated whether dual sensory impairment (DSI) adversely affects the deterioration of physical function in older adults compared to single sensory impairment (SSI, visual or auditory). We studied the association between DSI and declining physical function by analyzing the data of 2780 Korean community-dwelling adults aged 70-84 years. Sensory impairment was assessed through pure tone audiometry and visual acuity testing. Muscle strength (handgrip strength) and physical performance (timed up and go test and short physical performance battery (SPPB)) were evaluated. In the cross-sectional analysis, DSI was associated with higher odds of having low muscle strength (odds ratio (OR), 1.78; 95% confidence interval (CI), 1.27-2.48) and poor physical performance (SPPB: OR, 2.04; 95% CI, 1.38-3.00) than SSI. Among all sensory impairment groups in the longitudinal analysis, DSI at baseline increased the risk of deteriorating physical performance during the follow-up period (OR, 1.94; 95% CI, 1.31-2.88; p < 0.01) the most. DSI showed a more severe adverse effect on the decline in physical function among community-dwelling older adults than SSI. More comprehensive care is needed to prevent the deterioration of physical function in older adults due to DSI.

Liver X receptor controls follicular helper T cell differentiation via repression of TCF-1.

Liver X receptor (LXR) is a critical regulator of cholesterol homeostasis that inhibits T cell receptor (TCR)-induced proliferation by altering intracellular sterol metabolism. However, the mechanisms by which LXR regulates helper T cell subset differentiation remain unclear. Here, we demonstrate that LXR is a crucial negative regulator of follicular helper T (Tfh) cells in vivo. Both mixed bone marrow chimera and antigen-specific T cell adoptive cotransfer studies show a specific increase in Tfh cells among LXRß-deficient CD4+ T cell population in response to immunization and lymphocytic choriomeningitis mammarenavirus (LCMV) infection. Mechanistically, LXRß-deficient Tfh cells express augmented levels of T cell factor 1 (TCF-1) but comparable levels of Bcl6, CXCR5, and PD-1 in comparison with those of LXRß-sufficient Tfh cells. Loss of LXRß confers inactivation of GSK3ß induced by either AKT/Extracellular signal-regulated kinase (ERK) activation or Wnt/ß-catenin pathway, leading to elevated TCF-1 expression in CD4+ T cells. Conversely, ligation of LXR represses TCF-1 expression and Tfh cell differentiation in both murine and human CD4+ T cells. LXR agonist significantly diminishes Tfh cells and the levels of antigen-specific IgG upon immunization. These findings unveil a cell-intrinsic regulatory function of LXR in Tfh cell differentiation via the GSK3ß-TCF1 pathway, which may serve as a promising target for pharmacological intervention in Tfh-mediated diseases.

Functional Characterization of the GNAT Family Histone Acetyltransferase Elp3 and GcnE in Aspergillus fumigatus.

Post-translational modifications of chromatin structure by histone acetyltransferase (HATs) play a pivotal role in the regulation of gene expression and diverse biological processes. However, the function of GNAT family HATs, especially Elp3, in the opportunistic human pathogenic fungus Aspergillus fumigatus is largely unknown. To investigate the roles of the GNAT family HATs Elp3 and GcnE in the A. fumigatus, we have generated and characterized individual null Δelp3 and ΔgcnE mutants. The radial growth of fungal colonies was significantly decreased by the loss of elp3 or gcnE, and the number of asexual spores (conidia) in the ΔgcnE mutant was significantly reduced. Moreover, the mRNA levels of the key asexual development regulators were also significantly low in the ΔgcnE mutant compared to wild type (WT). Whereas both the Δelp3 and ΔgcnE mutants were markedly impaired in the formation of adherent biofilms, the ΔgcnE mutant showed a complete loss of surface structure and of intercellular matrix. The ΔgcnE mutant responded differently to oxidative stressors and showed significant susceptibility to triazole antifungal agents. Furthermore, Elp3 and GcnE function oppositely in the production of secondary metabolites, and the ΔgcnE mutant showed attenuated virulence. In conclusion, Elp3 and GcnE are associated with diverse biological processes and can be potential targets for controlling the pathogenic fungus.

Dual action of a tyrosinase-mesoporous silica nanoparticle complex for synergistic tissue adhesion.

Bridging biological tissues for immediate adhesion and long-term sustainability was accomplished using a combination of mesoporous silica nanoparticles (MSNs) and tyrosinase. Tyrosinase-loaded MSNs provided rapid physical adsorption, while tyrosinase within MSNs induced enzymatic chemical bond gluing of tissues. This synergistic strategy has robust potential in tissue adhesives for clinical settings.

Bacillus subtilis-Fermented Amomum xanthioides Ameliorates Metabolic-Syndrome-Like Pathological Conditions in Long-Term HFHFD-Fed Mice.

In modern society, numerous metabolic disorders are widespread globally. The present study aimed to demonstrate whether Bacillus subtilis-fermented Amomum xanthioides (BSAX) exerts anti-metabolic disturbance effects compared with the ethyl acetate fraction of Amomum xanthioides (EFAX), a previously verified functional fraction. Mice fed with a high-fat, high-fructose diet (HFHFD) for 10 wk presented a typical model of metabolic dysfunction, and BSAX significantly attenuated a string of metabolic-syndrome-related pathological parameters, such as body, fat, organ mass, lipid markers (TGs, TC, free fatty acids), and glucose metabolism (glucose, insulin), without influencing appetite. Further, BSAX markedly lowered malondialdehyde (MDA) and ROS in the blood and restored antioxidative parameters (SOD, GSH, and CAT in liver tissue, and total bilirubin in serum) by elevating Nrf2 and HO-1. Moreover, BSAX noticeably restored gut microbiota diversity and normalized lipid-metabolism-associated proteins, including SREBP-1, p-AMPK, and PPAR-α. Generally, most metabolic parameters were improved by BSAX to a greater extent than EFAX, except for liver weight and hepatic TC. In conclusion, BSAX alleviates metabolic dysfunction by enhancing lipid metabolism and antioxidative capacity and is more effective than EFAX. Therefore, the application of high-yield, effective BSAX might be a promising approach for curing and preventing metabolic disorders.

Polyglycerol and Poly(ethylene glycol) exhibit different effects on pharmacokinetics and antibody generation when grafted to nanoparticle surfaces.

Poly(ethylene glycol) (PEG) is widely employed for passivating nanoparticle (NP) surfaces to prolong blood circulation and enhance localization of NPs to target tissue. However, the immune response of PEGylated NPs-including anti-PEG antibody generation, accelerated blood clearance (ABC), and loss of delivery efficacy-is of some concern, especially for treatments that require repeat administrations. Although polyglycerol (PG), which has the same ethylene oxide backbone as PEG, has received attention as an alternative to PEG for NP coatings, the pharmacokinetic and immunogenic impact of PG has not been studied systematically. Here, linear PG, hyperbranched PG (hPG), and PEG-coated polylactide (PLA) NPs with varying surface densities were studied in parallel to determine the pharmacokinetics and immunogenicity of PG and hPG grafting, in comparison with PEG. We found that linear PG imparted the NPs a stealth property comparable to PEG, while hPG-grafted NPs needed a higher surface density to achieve the same pharmacokinetic impact. While linear PG-grafted NPs induced anti-PEG antibody production in mice, they exhibited minimal accelerated blood clearance (ABC) effects due to the poor interaction with anti-PEG immunoglobulin M (IgM). Further, we observed no anti-polymer IgM responses or ABC effects for hPG-grafted NPs.

The Lysine Demethylases KdmA and KdmB Differently Regulate Asexual Development, Stress Response, and Virulence in Aspergillus fumigatus.

Histone demethylases govern diverse cellular processes, including growth, development, and secondary metabolism. In the present study, we investigated the functions of two lysine demethylases, KdmA and KdmB, in the opportunistic human pathogenic fungus Aspergillus fumigatus. Experiments with mutants harboring deletions of genes encoding KdmA (ΔkdmA) and KdmB (ΔkdmB) showed that KdmA is necessary for normal growth and proper conidiation, whereas KdmB negatively regulates vegetative growth and conidiation. In both mutant strains, tolerance to H2O2 was significantly decreased, and the activities of both conidia-specific catalase (CatA) and mycelia-specific catalase (Cat1) were decreased. Both mutants had significantly increased sensitivity to the guanine nucleotide synthesis inhibitor 6-azauracil (6AU). The ΔkdmA mutant produced more gliotoxin (GT), but the virulence was not changed significantly in immunocompromised mice. In contrast, the production of GT and virulence were markedly reduced by the loss of kdmB. Comparative transcriptomic analyses revealed that the expression levels of developmental process-related genes and antioxidant activity-related genes were downregulated in both mutants. Taken together, we concluded that KdmA and KdmB have opposite roles in vegetative growth, asexual sporulation, and GT production. However, the two proteins were equally important for the development of resistance to 6AU.

The Chimeric Adenovirus (Ad5/35) Expressing Engineered Spike Protein Confers Immunity against SARS-CoV-2 in Mice and Non-Human Primates.

Several COVID-19 platforms have been licensed across the world thus far, but vaccine platform research that can lead to effective antigen delivery is still ongoing. Here, we constructed AdCLD-CoV19 that could modulate humoral immunity by harboring SARS-CoV-2 antigens onto a chimeric adenovirus 5/35 platform that was effective in cellular immunity. By replacing the S1/S2 furin cleavage sequence of the SARS-CoV-2 Spike (S) protein mounted on AdCLD-CoV19 with the linker sequence, high antigen expression was confirmed in various cell lines. The high levels of antigen expression contributed to antigen-specific antibody activity in mice and non-human primates (NHPs) with a single vaccination of AdCLD-CoV19. Furthermore, the adenovirus-induced Th1 immune response was specifically raised for the S protein, and these immune responses protected the NHP against live viruses. While AdCLD-CoV19 maintained neutralizing antibody activity against various SARS-CoV-2 variants, it was reduced to single vaccination for ß and ο variants, and the reduced neutralizing antibody activity was restored with booster shots. Hence, AdCLD-CoV19 can prevent SARS-CoV-2 with a single vaccination, and the new vaccine administration strategy that responds to various variants can maintain the efficacy of the vaccine.

Inhalable polymer nanoparticles for versatile mRNA delivery and mucosal vaccination.

An inhalable platform for mRNA therapeutics would enable minimally invasive and lung targeted delivery for a host of pulmonary diseases. Development of lung targeted mRNA therapeutics has been limited by poor transfection efficiency and risk of vehicle-induced pathology. Here we report an inhalable polymer-based vehicle for delivery of therapeutic mRNAs to the lung. We optimized biodegradable poly(amine-co-ester) polyplexes for mRNA delivery using end group modifications and polyethylene glycol. Our polyplexes achieved high transfection of mRNA throughout the lung, particularly in epithelial and antigen-presenting cells. We applied this technology to develop a mucosal vaccine for SARS-CoV-2. Intranasal vaccination with spike protein mRNA polyplexes induced potent cellular and humoral adaptive immunity and protected K18-hACE2 mice from lethal viral challenge. One-sentence summary: Inhaled polymer nanoparticles (NPs) achieve high mRNA expression in the lung and induce protective immunity against SARS-CoV-2.