Electric Field-Responsive Gold Nanoantennas for the Induction of a Locoregional Tumor pH Change Using Electrolytic Ablation Therapy.

Electrolytic ablation (EA) is a burgeoning treatment for solid tumors, in which electrical energy catalyzes a chemical reaction to generate reactive species that can eradicate cancer cells. However, the application of this technique has been constrained owing to the limited spatial effectiveness and complexity of the electrode designs. Therefore, the incorporation of nanotechnology into EA is anticipated to be a significant improvement. Herein, we present a therapeutic approach based on difructose dianhydride IV-conjugated polyethylenimine-polyethylene glycol-modified gold nanorods as electric nanoantennas and nanoelectrocatalysts for EA. We demonstrate that square-wave direct current (DC) fields trigger a reaction between water molecules and chloride ions on the gold nanorod surface, generating electrolytic products including hydrogen, oxygen, and chlorine gases near the electrodes, changing the pH, and inducing cell death. These electric nanoantennas showed significant efficacy in treating colorectal cancer both in vitro and in vivo after DC treatment. These findings clearly indicate that gold nanoantennas enhance the effectiveness of EA by creating a localized electric field and catalyzing electrolytic reactions for the induction of locoregional pH changes within the tumor. By overcoming the limitations of traditional EA and offering an enhanced level of tumor specificity and control, this nanotechnology-integrated approach advances further innovations in cancer therapies.

Antibody-conjugated and streptomycin-chitosan oligosaccharide-modified gold nanoshells for synergistic chemo-photothermal therapy of drug-resistant bacterial infection.

Despite the many advanced strategies that are available, rapid gene mutation in multidrug-resistant bacterial infections remains a major challenge. Combining new therapeutic strategies such as chemo-photothermal therapy (PTT) with high antibacterial efficiency against drug-resistant Listeria monocytogenes (LM) is urgently needed. Here, we report synergistic chemo-PTT against drug-resistant LM based on antibody-conjugated and streptomycin-chitosan oligosaccharide-modified gold nanoshells (anti-STR-CO-GNSs) as all-in-one nanotheranostic agents for the first time, which was used for accurate antibacterial applications. The anti-STR-CO-GNSs showed excellent photothermal conversion efficiency (31.97 %) and were responsive to near-infrared (NIR) and pH dual stimuli-triggered antibiotic release, resulting in outstanding chemo-photothermal effects against LM. In vitro chemo-photothermal effect of anti-STR-CO-GNSs with laser irradiation caused a greater antibacterial effect (1.37 %), resulting in more rapid killing of LM and prevention of LM regrowth. Most importantly, the mice receiving the anti-STR-CO-GNSs with laser irradiation specifically at the sites of LM infections healed almost completely, leaving only scars on the surface of the skin and resulting in superior inhibitory effects from combined chemo-PTT. Overall, our findings suggest that chemo-PTT using smart biocompatible anti-STR-CO-GNSs is a favorable potential alternative to combat the increasing threat of drug-resistant LM, which opens a new door for clinical anti-infection therapy in the future.

High titre neutralizing antibodies in response to SARS-CoV-2 infection require RBD-specific CD4 T cells that include proliferative memory cells.

Long-term immunity to SARS-CoV-2 infection, including neutralizing antibodies and T cell-mediated immunity, is required in a very large majority of the population in order to reduce ongoing disease burden. We have investigated the association between memory CD4 and CD8 T cells and levels of neutralizing antibodies in convalescent COVID-19 subjects. Higher titres of convalescent neutralizing antibodies were associated with significantly higher levels of RBD-specific CD4 T cells, including specific memory cells that proliferated vigorously in vitro. Conversely, up to half of convalescent individuals had low neutralizing antibody titres together with a lack of receptor binding domain (RBD)- specific memory CD4 T cells. These low antibody subjects had other, non-RBD, spike-specific CD4 T cells, but with more of an inhibitory Foxp3+ and CTLA-4+ cell phenotype, rather than the effector T- bet+, cytotoxic granzymes+ and perforin+ cells seen in high antibody subjects. Single cell transcriptomics of antigen-specific CD4+ T cells from high antibody subjects revealed heterogenous RBD-specific CD4+ T cells that comprised central memory, transitional memory and Tregs, as well as cytotoxic clusters containing diverse TCR repertoires, that were absent in individuals with low antibody levels. However, vaccination in low antibody convalescent individuals led to a slight but significant improvement in RBD-specific memory CD4 T cells and increased neutralizing antibody titres. Our results suggest that targeting CD4 T cell epitopes proximal to and within the RBD- region should be prioritized in booster vaccines. One Sentence SummaryIndividuals with low neutralising antibody titres may be at risk of SARS-CoV-2 re-infection due to a failure to generate a high quality CD4 T cell response specific for receptor binding domain (RBD), including memory CD4 T cells that proliferate in vitro in response to RBD, and which are also therefore an important target for vaccine design.

Graphene Oxide-Reinforced Alginate Hydrogel for Controlled Release of Local Anesthetics: Synthesis, Characterization, and Release Studies.

In pain relief, lidocaine has gained more attention as a local anesthetic. However, there are several side effects that limit the use of local anesthetics. Therefore, it is hypothesized that a hydrogel system with facile design can be used for prolonged release of lidocaine. In this study, we developed a formulation comprises of sodium alginate (SA) and graphene oxide (GO) to prolong the release of lidocaine. The gelation was induced by physically crosslinking the alginate with Ca2+ ions. The formation of blank SA and GO-reinforced SA hydrogels was investigated with different concentration of Ca2+ ions. The controlled release of lidocaine hydrochloride (LH) on both hydrogel systems was studied in PBS solution. The GO-reinforced SA hydrogels exhibited more sustained release than SA hydrogels without GO. In vitro biocompatibility test in L929 fibroblast cells confirmed the non-toxic property of hydrogels. Furthermore, to prove the in-situ gelation and biodegradability of hydrogels the hydrogels were injected on mice model and confirmed the stable gel formation. The hydrogels implanted onto the subcutaneous tissue of hydrogels retained over one week. These results indicate that LH-loaded GO-reinforced SA hydrogel can be a potential biomaterial for controlled release of local anesthetics.

Clonal dynamics of SARS-CoV-2-specific T cells in children and adults with COVID-19

Children infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) develop less severe coronavirus disease 2019 (COVID-19) than adults. The mechanisms for the age-specific differences and the implications for infection-induced immunity are beginning to be uncovered. We show by longitudinal multimodal analysis that SARS-CoV-2 leaves a small footprint in the circulating T cell compartment in children with mild/asymptomatic COVID-19 compared to adult household contacts with the same disease severity who had more evidence of systemic T cell interferon activation, cytotoxicity and exhaustion. Children harbored diverse polyclonal SARS-CoV- 2-specific naive T cells whereas adults harbored clonally expanded SARS-CoV-2-specific memory T cells. More naive interferon-activated CD4+ T cells were recruited into the memory compartment and recovery was associated with the development of robust CD4+ memory T cell responses in adults but not children. These data suggest that rapid clearance of SARS-CoV-2 in children may compromise their cellular immunity and ability to resist reinfection. HIGHLIGHTSO_LIChildren have diverse polyclonal SARS-CoV-2-specific naive T cells C_LIO_LIAdults have clonally expanded exhausted SARS-CoV-2-specific memory T cells C_LIO_LIInterferon-activated naive T cells differentiate into memory T cells in adults but not children C_LIO_LIAdults but not children develop robust memory T cell responses to SARS-CoV-2 C_LI O_FIG O_LINKSMALLFIG WIDTH=177 HEIGHT=200 SRC="FIGDIR/small/478400v1_ufig1.gif" ALT="Figure 1"> View larger version (44K): org.highwire.dtl.DTLVardef@e9586org.highwire.dtl.DTLVardef@17aaf37org.highwire.dtl.DTLVardef@18575e0org.highwire.dtl.DTLVardef@fde4ae_HPS_FORMAT_FIGEXP M_FIG C_FIG

Five new seco-labdane-type diterpenoids from Caesalpinia latisiliqua.

Five new seco-labdane-type diterpenoids, caesalatisics A-E (1-5), were isolated from the leaves of Caesalpinia latisiliqua (Cav.) Hattink. Their chemical structures were determined using 1D and 2D NMR, mass spectra, and circular dichroism spectroscopies.

Therapeutic effects of boronate ester cross-linked injectable hydrogels for the treatment of hepatocellular carcinoma.

Hepatocellular carcinoma is the most common malignancy with a high incidence rate and is the leading cause of cancer-related deaths. Herein, we developed a thermo-responsive hydrogel comprising poly(ε-caprolactone-co-lactide)-b-poly(ethylene glycol)-b-poly(ε-caprolactone-co-lactide (PCLA) that exhibits acidity-accelerated delivery of the tumor-targeting glucuronic acid-bearing doxorubicin (DOX-pH-GA) conjugate into tumor tissues. The PCLA copolymer was post-modified with boronic acid (BA-PCLA) to covalently cross-link with the pH-responsive DOX-pH-GA conjugate. The BA-PCLA copolymer effectively coordinated with the DOX-pH-GA conjugate through the boronate ester formation and showed a lower critical gelation temperature. The DOX conjugated via boronate ester exhibited a sustained release in vitro. Subcutaneous administration of PCLA copolymers formed in situ gels in the subcutaneous layers of Sprague-Dawley rats and degraded after 6 weeks. Similarly, BA-PCLA copolymers coordinated with DOX-pH-GA formed a stable in situ gel in vivo. In vivo imaging studies demonstrated that DOX-pH-GA was released in a sustained manner. The anti-tumor activity of the DOX releasing injectable hydrogel was examined using a HepG2 liver cancer xenograft model. The in vivo antitumor effect demonstrated that the DOX releasing hydrogel depot remarkably suppresses the tumor growth. These results demonstrate that the pH-responsive DOX releasing thermo-responsive hydrogel depot has great potential for application in localized anticancer therapy.

No evidence that plasmablasts transdifferentiate into developing neutrophils in severe COVID-19 disease

A recent study by Wilk et al. of the transcriptome of peripheral blood mononuclear cells (PBMCs) in seven patients hospitalized with COVID-19 described a population of "developing neutrophils" that were "phenotypically related by dimensionality reduction" to plasmablasts, and that these two cell populations represent a "linear continuum of cellular phenotype"1. The authors suggest that, in the setting of acute respiratory distress syndrome (ARDS) secondary to severe COVID-19, a "differentiation bridge from plasmablasts to developing neutrophils" connected these distantly related cell types. This conclusion is controversial as it appears to violate several basic principles in cell biology relating to cell lineage identity and fidelity. Correctly classifying cells and their developmental history is an important issue in cell biology and we suggest that this conclusion is not supported by the data as we show here that: (1) regressing out covariates such as unique molecular identifiers (UMIs) can lead to overfitting; and (2) that UMAP embeddings may reflect the expression of similar genes but not necessarily direct cell lineage relationships.

Prostate cancer cell-intrinsic interferon signaling regulates dormancy and metastatic outgrowth in bone.

The latency associated with bone metastasis emergence in castrate-resistant prostate cancer is attributed to dormancy, a state in which cancer cells persist prior to overt lesion formation. Using single-cell transcriptomics and ex vivo profiling, we have uncovered the critical role of tumor-intrinsic immune signaling in the retention of cancer cell dormancy. We demonstrate that loss of tumor-intrinsic type I IFN occurs in proliferating prostate cancer cells in bone. This loss suppresses tumor immunogenicity and therapeutic response and promotes bone cell activation to drive cancer progression. Restoration of tumor-intrinsic IFN signaling by HDAC inhibition increased tumor cell visibility, promoted long-term antitumor immunity, and blocked cancer growth in bone. Key findings were validated in patients, including loss of tumor-intrinsic IFN signaling and immunogenicity in bone metastases compared to primary tumors. Data herein provide a rationale as to why current immunotherapeutics fail in bone-metastatic prostate cancer, and provide a new therapeutic strategy to overcome the inefficacy of immune-based therapies in solid cancers.

Modularly engineered alginate bioconjugate hydrogel as biocompatible injectable scaffold for in situ biomineralization.

In the present study, a type of bioconjugate was synthesized by post modification of alginate by conjugating temperature-responsive poly(ε-caprolactone-co-lactide)-b-poly(ethylene glycol)-b-poly(ε-caprolactone-co-lactide) and O-phosphorylethanolamine as phosphorylation functional groups. Freely flowing bioconjugate sols at low temperature can transform to stable viscoelastic gels at the physiological temperature (37 °C). Subcutaneous administration of temperature-responsive bioconjugate sols into the dorsal region of Sprague-Dawley rats formed in situ hydrogel. in situ formation of bioconjugate gels in stimulated body fluids at 37 °C showed nucleation and hydroxyapatite mineral growth. Furthermore, hydroxyapatite growth was also found in in vivo gels, which suggested the potential of alginate-based bioconjugate gels as a scaffold for bone engineering. Bone morphogenetic protein 2 (BMP-2)-loaded bioconjugate formed stable gel in vivo, and demonstrated sustained release. BMP-2-loaded bioconjugates exhibited in situ biomineralization in vivo. These results imply that the in situ formation of injectable biomimetic materials has potential for bone tissue engineering applications.

Smart injectable biogels based on hyaluronic acid bioconjugates finely substituted with poly(ß-amino ester urethane) for cancer therapy.

Development of implantable material to control the release of chemotherapeutics in the body is a promising approach to control cancer cell proliferation; however, implantation requires surgical intervention. Herein, we propose the in situ formation of injectable biogels (IBGs) for the programmed delivery of potent chemotherapeutic drugs. IBGs are developed via cohesive molecular assembly of a polysaccharide-polymer network comprised of hyaluronic acid-poly(ß-amino urethane). Biocompatible IBGs could be administered subcutaneously through a hypodermic needle in vivo to subsequently assemble into a microporous network. The hyaluronic acid-shielded network mimics the natural extracellular matrix, avoiding rapid degradation of IBGs, with a soft texture and adhesiveness facilitating integration with dermal tissues after subcutaneous implantation. The natural-mimicking architecture confers the IBG network controlled degradation and bioresorbable properties. Subcutaneous administration of IBGs controlled the delivery of a therapeutic agent in a spatio-temporal manner. Therapeutic agents delivered near the tumors in a sustained manner were effectively infiltrated into the thick solid tumors and provide a durable and enhanced anti-tumor response in the B16/OVA melanoma model in vivo. These results indicate that IBGs could be potential medical interventions for the treatment of cancers.

High-throughput targeted long-read single cell sequencing reveals the clonal and transcriptional landscape of lymphocytes.

High-throughput single-cell RNA sequencing is a powerful technique but only generates short reads from one end of a cDNA template, limiting the reconstruction of highly diverse sequences such as antigen receptors. To overcome this limitation, we combined targeted capture and long-read sequencing of T-cell-receptor (TCR) and B-cell-receptor (BCR) mRNA transcripts with short-read transcriptome profiling of barcoded single-cell libraries generated by droplet-based partitioning. We show that Repertoire and Gene Expression by Sequencing (RAGE-Seq) can generate accurate full-length antigen receptor sequences at nucleotide resolution, infer B-cell clonal evolution and identify alternatively spliced BCR transcripts. We apply RAGE-Seq to 7138 cells sampled from the primary tumor and draining lymph node of a breast cancer patient to track transcriptome profiles of expanded lymphocyte clones across tissues. Our results demonstrate that RAGE-Seq is a powerful method for tracking the clonal evolution from large numbers of lymphocytes applicable to the study of immunity, autoimmunity and cancer.

Clinical impact of the two ART resistance markers, K13 gene mutations and DPC3 in Vietnam.

BACKGROUND: In Vietnam, a rapid decline of P. falciparum malaria cases has been documented in the past years, the number of Plasmodium falciparum malaria cases has rapidly decreased passing from 19.638 in 2012 to 4.073 cases in 2016. Concomitantly, the spread of artemisinin resistance markers is raising concern on the future efficacy of the ACTs. An evaluation of the clinical impact of the artemisinin resistance markers is therefore of interest. METHODS: The clinical effectiveness of dihydroartemisinin-piperaquine therapy (DHA-PPQ) has been evaluated in three districts characterized by different rates of ART resistance markers: K13(C580Y) mutation and delayed parasite clearance on day 3 (DPC3). Patients were stratified in 3 groups a) no markers, b) one marker (suspected resistance), c) co-presence of both markers (confirmed resistance). In the studied areas, the clinical effectiveness of DHA-PPQ has been estimated as malaria recrudescence within 60 days. RESULTS: The rate of K13(C580Y) ranged from 75.8% in Krong Pa to 1.2% in Huong Hoa district. DPC3 prevalence was higher in Krong Pa than in Huong Hoa (86.2% vs 39.3%). In the two districts, the prevalence of confirmed resistance was found in 69.0% and 1.2% of patients, respectively. In Thuan Bac district, we found intermediate prevalence of confirmed resistance. Treatment failure was not evidenced in any district. PPQ resistance was not evidenced. Confirmed resistance was associated to the persistence of parasites on day 28 and to 3.4-fold higher parasite density at diagnosis. The effectiveness of malaria control strategies was very high in the studied districts. CONCLUSION: No treatment failure has been observed in presence of high prevalence of ART resistance and in absence of PPQ resistance. K13(C580Y) was strongly associated to higher parasitemia at admission, on days 3 and 28. Slower parasite clearance was also observed in younger patients.

Modularly engineered injectable hybrid hydrogels based on protein-polymer network as potent immunologic adjuvant in vivo.

Lymphoid organs, which are populated by dendritic cells (DCs), are highly specialized tissues and provide an ideal microenvironment for T-cell priming. However, intramuscular or subcutaneous delivery of vaccine to DCs, a subset of antigen-presenting cells, has failed to stimulate optimal immune response for effective vaccination and need for adjuvants to induce immune response. To address this issue, we developed an in situ-forming injectable hybrid hydrogel that spontaneously assemble into microporous network upon subcutaneous administration, which provide a cellular niche to host immune cells, including DCs. In situ-forming injectable hybrid hydrogelators, composed of protein-polymer conjugates, formed a hydrogel depot at the close proximity to the dermis, resulting in a rapid migration of immune cells to the hydrogel boundary and infiltration to the microporous network. The biocompatibility of the watery microporous network allows recruitment of DCs without a DC enhancement factor, which was significantly higher than that of traditional hydrogel releasing chemoattractants, granulocyte-macrophage colony-stimulating factor. Owing to the sustained degradation of microporous hydrogel network, DNA vaccine release can be sustained, and the recruitment of DCs and their homing to lymph node can be modulated. Furthermore, immunization of a vaccine encoding amyloid-ß fusion proteinbearing microporous network induced a robust antigen-specific immune response in vivo and strong recall immune response was exhibited due to immunogenic memory. These hybrid hydrogels can be administered in a minimally invasive manner using hypodermic needle, bypassing the need for cytokine or DC enhancement factor and provide niche to host immune cells. These findings highlight the potential of hybrid hydrogels that may serve as a simple, yet multifunctional, platform for DNA vaccine delivery to modulate immune response.

Anatomical Characteristics and Variants of Prostatic Artery in Patients of Benign Hyperplasia Prostate by Digital Subtraction Angiography.

AIM: This work is aimed to describe anatomical features and variants of the prostatic artery (PA) using digital subtraction angiography (DSA). METHODS: This is a descriptive statistic study. We reviewed the DSA of 348 patients, who had a PA embolisation to reduce the benign prostatic hyperplasia (BPH) symptoms at Radiology Department of Bach Mai Hospital from Oct - 2014 to Oct - 2018. RESULTS: PA was found at 660 pelvic halves, of which 30 pelvic halves (4.5%) had two PAs, 630 pelvic halves had one PA. In terms of the origin of PA, in total 690 PAs, the percentage of type 1, 2, 3, 4 and 5 was successively 33.9%, 13.9%, 18.3%, 23.9% and 10.4%, respectively. Atherosclerosis of PA observed in 20.9%. The 'corkscrew' pattern was found in 30.4%. The average diameter of PA was 1.5 ± 0.34mm. The anastomosis of PA with surrounding arteries was common. PA may supply rectum (6.1%), seminal vesical (9.6%), bladder (5.2%), contralateral prostatic parenchyma (13.0%), surrounding soft-tissues (3.5%). CONCLUSION: The common trunk with SVA superior vesical artery was the most common origin of PA. Anastomoses of PA with surrounding tissues were complex.

Smart vaccine delivery based on microneedle arrays decorated with ultra-pH-responsive copolymers for cancer immunotherapy.

Despite the tremendous potential of DNA-based cancer vaccines, their efficacious delivery to antigen presenting cells to stimulate both humoral and cellular response remains a major challenge. Although electroporation-based transfection has improved performance, an optimal strategy for safe and pain-free vaccination technique remains elusive. Herein, we report a smart DNA vaccine delivery system in which nanoengineered DNA vaccine was laden on microneedles (MNs) assembled with layer-by-layer coating of ultra-pH-responsive OSM-(PEG-PAEU) and immunostimulatory adjuvant poly(I:C), a synthetic double stranded RNA. Transcutaneous application of MN patches onto the mice skin perforate the stratum corneum with minimal cell damage; subsequent disassembly at the immune-cell-rich epidermis/dermis allows the release of adjuvants and DNA vaccines, owing to the ultra-sharp pH-responsive nature of OSM-(PEG-PAEU). The released adjuvant and DNA vaccine can enhance dendritic cell maturation and induce type I interferons, and thereby produce antigen-specific antibody that can achieve the antibody-dependent cell-mediated cytotoxicity (ADCC) and CD8+ T cell to kill cancer cells. Strikingly, transcutaneous application of smart vaccine formulation in mice elicited 3-fold greater frequencies of Anti-OVA IgG1 serum antibody and 3-fold excess of cytotoxic CD8+ T cell than soluble DNA vaccine formulation. As a consequence, the formulation rejected the murine B16/OVA melanoma tumors in C57BL/6 mice through the synergistic activation of antigen-specific ADCC and cytotoxic CD8+ T cells. The maneuvered use of vaccine and adjuvant poly(I:C) in MNs induces humoral and cellular immunity, which provides a promising vaccine technology that shows improved efficacy, compliance, and safety.

Bioinspired pH- and Temperature-Responsive Injectable Adhesive Hydrogels with Polyplexes Promotes Skin Wound Healing.

Despite great potential, the delivery of genetic materials into cells or tissues of interest remains challenging owing to their susceptibility to nuclease degradation, lack of permeability to the cell membrane, and short in vivo half-life, which severely restrict their widespread use in therapeutics. To surmount these shortcomings, we developed a bioinspired in situ-forming pH- and temperature-sensitive injectable hydrogel depot that could control the delivery of DNA-bearing polyplexes for versatile biomedical applications. A series of multiblock copolymer, comprised of water-soluble poly(ethylene glycol) (PEG) and pH- and temperature-responsive poly(sulfamethazine ester urethane) (PSMEU), has been synthesized as in situ-forming injectable hydrogelators. The free-flowing PEG-PSMEU copolymer sols at high pH and room temperature (pH 8.5, 23 °C) were transformed to stable gel at the body condition (pH 7.4, 37 °C). Physical and mechanical properties of hydrogels, including their degradation rate and viscosity, are elegantly controlled by varying the composition of urethane ester units. Subcutaneous administration of free-flowing PEG-PSMEU copolymer sols to the dorsal region of Sprague-Dawley rats instantly formed hydrogel depot. The degradation of the hydrogel depot was slow at the beginning and found to be bioresorbable after two months. Cationic protein or DNA-bearing polyplex-loaded PEG-PSMEU copolymer sols formed stable gel and controlled its release over 10 days in vivo. Owing to the presence of urethane linkages, the PEG-PSMEU possesses excellent adhesion strength to wide range of surfaces including glass, plastic, and fresh organs. More importantly, the hydrogels effectively adhered on human skin and peeled easily without eliciting an inflammatory response. Subcutaneous implantation of PEG-PSMEU copolymer sols effectively sealed the ruptured skin, which accelerated the wound healing process as observed by the skin appendage morphogenesis. The bioinspired in situ-forming pH- and temperature-sensitive injectable adhesive hydrogel may provide a promising platform for myriad biomedical applications as controlled delivery vehicle, adhesive, and tissue regeneration.

New Compounds and Potential Candidates for Drug Discovery from Medicinal Plants of Vietnam.

The study of natural products introduces interesting new bioorganic structures and potential candidates for the drug discovery stage in the development of innovative drugs. Vietnam enjoys a broad biodiversity of native plant species, microorganisms, marine organisms, and a long tradition of using herbal remedies. Thus, the study of medicinal plants in determining the basis of their efficacy and safety is an important task for modern researchers in Vietnam. The present review covers literature on new compounds elucidated from the systematic study of medicinal plants within some popular genera in Vietnam, as well as their significant biological activities.

Microneedle arrays coated with charge reversal pH-sensitive copolymers improve antigen presenting cells-homing DNA vaccine delivery and immune responses.

Successful delivery of a DNA vaccine to antigen-presenting cells and their subsequent stimulation of CD4+ and CD8+ T cell immunity remains an inefficient process. In general, the delivery of prophylactic vaccines is mainly mired by low transfection efficacy, poor immunogenicity, and safety issues from the materials employed. Currently, several strategies have been exploited to improve immunogenicity, but an effective strategy for safe and pain-free delivery of DNA vaccines is complicated. Herein, we report the rapid delivery of polyplex-based DNA vaccines using microneedle arrays coated with a polyelectrolyte multilayer assembly of charge reversal pH-responsive copolymer and heparin. The charge reversal pH-responsive copolymer, composed of oligo(sulfamethazine)-b-poly(ethylene glycol)-b-poly(amino urethane) (OSM-b-PEG-b-PAEU), was used as a triggering layer in the polyelectrolyte multilayer assembly on microneedles. Charge reversal characteristics of this copolymer, that is, the OSM-b-PEG-b-PAEU copolymer exhibit, positive charge at low pH (pH4.03) and becoming negative charge when exposed to physiological pH conditions (pH7.4), allowing the facile assembly and disassembly of polyelectrolyte multilayers. The electrostatic repulsion between heparin and OSM-b-PEG-b-PAEU charge reversal copolymer triggered the release of DNA vaccines. DNA vaccines laden on microneedles are effectively transfected into RAW 264.7 macrophage cells in vitro. Vaccination of BALB/c mice by DNA vaccine-loaded microneedle arrays coated with a polyelectrolyte multilayer generated antigen-specific robust immune responses. These findings provide potential strategy of charge reversal pH-responsive copolymers coated microneedles for DNA vaccine delivery.

Bioengineered robust hybrid hydrogels enrich the stability and efficacy of biological drugs.

Biological drugs are exquisitely tailored components offering the advantages of high specificity and efficacy that are considered safe for treating diseases. Nevertheless, the effectiveness of biological drugs is limited by their inherent short biological half-life and poor stability in vivo. Herein, we engineered a novel delivery platform based on hybrid injectable hydrogels, in which pH- and temperature-responsive biodegradable copolymers were site-specifically coupled to the sulfhydryl group of human serum albumin, which effectively enhances the stability and circulation half-life of the biological drug, recombinant uricase enzyme (Uox). The albumin ligand conjugated to the Uox allowed specific-binding of the enzyme within the protein shell, and the synthetic polymers effectively shield the protein-enzyme complex. Such close confinement exhibits strong resistance towards various physical, chemical and therapeutically relevant stressors such as temperature, pH and proteases. Subcutaneous administration of Uox-loaded bioengineered hybrid hydrogel improved the pharmacokinetics by prolonging its circulation half-life. As a consequence, the bioengineered hybrid hydrogel normalized the serum uric acid level in hypoxanthine/potassium oxonate-induced hyperuricemia mice, and no obvious side effects were observed in the major organs. The characteristic of the bioengineered hydrogel networks applicable to a variety of biological drugs by simple mixing that unlock the possibility of adapting biological drugs to therapeutic applications.