Recent progress of vaccines administration via microneedles for cancer immunotherapy

Therapeutic cancer vaccines have undergone a resurgence in the past decade.Because of the high level of immune cell accumulation and abundant capillary lymphatic system in the dermis,percutaneous vaccination is considered to be an ideal treatment route.For convenient administration,the recent development of microneedles(MNs)provides a safe,painless,and low-cost transdermal delivery strategy,which could bypass the first-pass metabolism of vaccines for enhanced stability and bioavailability.However,the therapeutic effect of MNs-based cancer vaccines is not optimal,which is limited by the complex set of host,tumor,and environmental factors,as well as the limited vaccine loading capacity.Therefore,further improvements are still required to push their clinical translation.In this critical review,we deliberate on how to improve the therapeutic effect of MNs-based vaccines for cancer immunotherapy,summarize the recent advances in MNs-based cancer vaccination,and provide an overview of various design strategies and mechanisms for active or passive targeting delivery,aiming to develop safer,more effective,and more stable MNs-based cancer vaccines.Finally,we briefly describe the potential of vaccine platforms in combination with other therapies,suggest the need to design vaccines according to specific circumstances,and discuss the biosafety of repeated administration for enhancing clinical efficacy.

Single-cell RNA sequencing reveals the transcriptomic landscape of kidneys in patients with ischemic acute kidney injury

Background:Ischemic acute kidney injury(AKI)is a common syndrome associated with considerable mortality and healthcare costs.Up to now,the underlying pathogenesis of ischemic AKI remains incompletely understood,and specific strategies for early diagnosis and treatment of ischemic AKI are still lacking.Here,this study aimed to define the transcriptomic landscape of AKI patients through single-cell RNA sequencing(scRNA-seq)analysis in kidneys.Methods:In this study,scRNA-seq technology was applied to kidneys from two ischemic AKI patients,and three human public scRNA-seq datasets were collected as controls.Differentially expressed genes(DEGs)and cell clusters of kidneys were determined.Gene ontology(GO)and Kyoto Encyclopedia of Genes and Genomes(KEGG)pathway enrichment analysis,as well as the ligand-receptor interaction between cells,were performed.We also validated several DEGs expression in kidneys from human ischemic AKI and ischemia/reperfusion(I/R)injury induced AKI mice through immunohistochemistry staining.Results:15 distinct cell clusters were determined in kidney from subjects of ischemic AKI and control.The injured proximal tubules(PT)displayed a proapoptotic and proinflammatory phenotype.PT cells of ischemic AKI had up-regulation of novel pro-apoptotic genes including USP47,RASSF4,EBAG9,IER3,SASH1,SEPTIN7,and NUB1,which have not been reported in ischemic AKI previously.Several hub genes were validated in kidneys from human AKI and renal I/R injury mice,respectively.Furthermore,PT highly expressed DEGs enriched in endoplasmic reticulum stress,autophagy,and retinoic acid-inducible gene I(RIG-I)signaling.DEGs overexpressed in other tubular cells were primarily enriched in nucleotide-binding and oligomerization domain(NOD)-like receptor signaling,estrogen signaling,interleukin(IL)-12 signaling,and IL-17 signaling.Overexpressed genes in kidney-resident immune cells including macrophages,natural killer T(NKT)cells,monocytes,and dendritic cells were associated with leukocyte activation,chemotaxis,cell adhesion,and complement activation.In addition,the ligand-receptor interactions analysis revealed prominent communications between macrophages and monocytes with other cells in the process of ischemic AKI.Conclusion:Together,this study reveals distinct cell-specific transcriptomic atlas of kidney in ischemic AKI patients,altered signaling pathways,and potential cell-cell crosstalk in the development of AKI.These data reveal new insights into the pathogenesis and potential therapeutic strategies in ischemic AKI.

Converting bacteria into autologous tumor vaccine via surface biomineralization of calcium carbonate for enhanced immunotherapy

Autologous cancer vaccine that stimulates tumor-specific immune responses for personalized immunotherapy holds great potential for tumor therapy.However,its efficacy is still suboptimal due to the immunosuppressive tumor microenvironment(ITM).Here,we report a new type of bacteria-based autologous cancer vaccine by employing calcium carbonate(CaCO_(3))biomineralized Salmonella(Sal)as an in-situ cancer vaccine producer and systematical ITM regulator.CaCO_(3) can be facilely coated on the Sal surface with calcium ionophore A23187 co-loading,and such biomineralization did not affect the bioactivities of the bacteria.Upon intratumoral accumulation,the CaCO_(3) shell was decomposed at an acidic microenvironment to atenuate tumor acidity,accompanied by the release of Sal and Ca^(2+)/A23187.Specifically,Sal served as a cancer vaccine producer by inducing cancer cells'immunogenic cell death(ICD)and promoting the gap junction formation between tumor cells and dendritic cells(DCs)to promote antigen presentation.Ca^(2+),on the other hand,was intermalized into various types of immune cells with the aid of A23187 and synergized with Sal to systematically regulate the immune system,including DCs maturation,macrophages polarization,and T cells activation.As a result,such bio-vaccine achieved remarkable effcacy against both primary and metastatic tumors by eliciting potent anti-tumor immunity with full biocompatibility.This work demonstrated the potential of bioengineered bacteria as bio-active vaccines for enhanced tumor immunotherapy.

Uptake and Intracellular Fate of Fluorophore Labeled Metal−Organic-Framework(MOF)Nanoparticles

The uptake and the fate of Zr-based metal−organic-framework nanoparticles labeled with organic fluorophores in HeLa cells has been monitored with fluorescence detection and elemental analysis.The nanoparticles have been selected as a model system of carrier nanoparticles(here Zr-based metal−organic-framework nanoparticles)with integrated cargo molecules(here organic fluorophores),with aze that does not allow for efficient exocytosis,a material which only partly degrades under acidic conditions as present in endosomes/lysosomes,and with limited colloidal stability.Data show that,for Zr-based metal−organic-framework nanoparticles of 40 nm size as investigated here,the number of nanoparticles per cells decreases faster due to particle redistribution upon proliferation than due to nanoparticle exocytosis and that,thus,also for this system,exocytosis is not an efficient pathway for clearance of the nanoparticles from the cells.

Repurposing disulfiram with CuET nanocrystals:Enhancing anti-pyroptotic effect through NLRP3 inflammasome inhibition for treating inflammatory bowel diseases

Drug repurposing offers a valuable strategy for identifying new therapeutic applications for existing drugs.Recently,disulfiram(DSF),a drug primarily used for alcohol addiction treatment,has emerged as a potential treatment for inflammatory diseases by inhibiting pyroptosis,a form of programmed cell death.The therapeutic activity of DSF can be further enhanced by the presence of Cu^(2+),although the underlying mechanism of this enhancement remains unclear.In this study,we investigated the mechanistic basis of Cu^(2+)-induced enhancement and discovered that it is attributed to the formation of a novel copper ethylthiocarbamate(CuET)complex.CuET exhibited significantly stronger anti-pyroptotic activity compared to DSF and employed a distinct mechanism of action.However,despite its potent activity,CuET suffered from poor solubility and limited permeability,as revealed by our druggability studies.To overcome these intrinsic limitations,we developed a scalable method to prepare CuET nanocrystals(CuET NCs)using a metal coordination-driven self-assembly approach.Pharmacokinetic studies demonstrated that CuET NCs exhibited a 6-fold improvement in bioavailability.Notably,CuET NCs exhibited high biodistribution in the intestine,suggesting their potential application for the treatment of inflammatory bowel diseases(IBDs).To evaluate their therapeutic efficacy in vivo,we employed a murine model of DSS-induced colitis and observed that CuET NCs effectively attenuated inflammation and ameliorated colitis symptoms.Our findings highlight the discovery of CuET as a potent anti-pyroptotic agent,and the development of CuET NCs represents a novel approach to enhance the druggability of CuET.

Harnessing bacteria for tumor therapy:Current advances and challenges

After a century of standstill,bacteria-based tumor therapy has resurged recently benefiting from the revolution of tumor immunotherapy,which provides unique solutions to tackle the obstacles of traditional tumor treatments.Obligate and facultative anaerobes with active tropism can selectively colonize at tumor sites and suppress tumor growth via different mechanisms,serving as attractive tools for tumor treatment either as a monotherapy or combining with other therapies for synergistic anti-tumor effects.In this critical review,we introduce the recent advances of bacteria-based tumor therapy from the following aspects.First,the general properties of bacteria are reviewed emphasizing on their structural components related to tumor immunotherapy,and the main bacteria that have been used in tumor therapy are listed.Then,the benefits of bacteria for tumor therapy are illustrated,such as tumor targetability,deep penetration,and facile genetic engineering for attenuation,enhanced efficacy,as well as bioimaging.Next,anti-tumor mechanisms of bacteria are summarized,which refer to intrinsic tumoricidal activities,immune activation,bacteria metabolism,and their capability to regulate gut microbiota homeostasis.Moreover,bacteria could act as carriers to deliver various types of therapeutics to achieve combination therapy with improved efficacy.In addition,several challenges for anti-tumor applications of bacteria are discussed regarding the delivery,efficacy and safety issues,and potential solutions are also provided.Finally,the possible improvements and perspectives are discussed in the end,which provide a guideline for the design of advanced bacteria-based tumor therapeutics in the future.

Salmonella-mediated blood-brain barrier penetration,tumor homing and tumor microenvironment regulation for enhanced chemo/bacterial glioma therapy

Chemotherapy is an important adjuvant treatment of glioma,while the efficacy is far from satisfactory,due not only to the biological barriers of blood-brain barrier(BBB)and blood-tumor barrier(BTB)but also to the intrinsic resistance of glioma cells via multiple survival mechanisms such as upregulation of P-glycoprotein(P-gp).To address these limitations,we report a bacteria-based drug delivery strategy for BBB/BTB transportation,glioma targeting,and chemo-sensitization.Bacteria selectively colonized into hypoxic tumor region and modulated tumor microenvironment,including macrophages repolarization and neutrophils infiltration.Specifically,tumor migration of neutrophils was employed as hitchhiking delivery of doxorubicin(DOX)-loaded bacterial outer membrane vesicles(OMVs/DOX).By virtue of the surface pathogen-associated molecular patterns derived from native bacteria,OMVs/DOX could be selectively recognized by neutrophils,thus facilitating glioma targeted delivery of drug with significantly enhanced tumor accumulation by 18-fold as compared to the classical passive targeting effect.Moreover,the P-gp expression on tumor cells was silenced by bacteria typeⅢsecretion effector to sensitize the efficacy of DOX,resulting in complete tumor eradication with 100%survival of all treated mice.In addition,the colonized bacteria were finally cleared by anti-bacterial activity of DOX to minimize the potential infection risk,and cardiotoxicity of DOX was also avoided,achieving excellent compatibility.This work provides an efficient trans-BBB/BTB drug delivery strategy via cell hitchhiking for enhanced glioma therapy.

Copper carbonate nanoparticles as an effective biomineralized carrier to load macromolecular drugs for multimodal therapy

Macromolecular drugs have attracted great interest as biotherapy to cure previously untreatable diseases.For clinical translation,biomacromolecules encounter several common druggability difficulties,such as in vivo instability and poor penetration to cross physiologic barriers,thus requiring sophisticated systems for drug delivery.Inspired by the natural biomineralization via interaction between inorganic ions and biomacromolecules,herein we rationally screened biocompatible transition metals to biomineralize with carbonate for macromolecules loading.Among the metal ions,Cu^(2+)was found to be the best candidate,and its superiority over the widely studied Ca^(2+)minerals was also demonstrated.Capitalized on this finding,copper carbonate nanoparticles were prepared via a simple mixing process to co-load glucose oxidase(GOx)and a HIF-αDNAzyme(DZ),achieving ultra-high loading capacity of 61%.Upon encapsulation into nanoparticles,enzymatic activity of both drugs was passivated to avoid potential side-effects during circulation,while the drugs could be rapidly released within 1 h in response to acidic p H to fully recover their activities.The nanoparticles could accumulate into tumor via intravenous injection,facilitate the cell membrane penetration,and release the payloads of GOx,DZ and Cu^(2+)inside cells to exert a series of anti-tumor effects.GOx caused tumor starvation by catalytic glucose consumption,and the concomitantly generated H_(2)O_(2)byproduct boosted the Cu^(2+)-mediated chemodynamic therapy(CDT).Meanwhile,the DZ silenced HIF-αexpression to sensitize both starvation therapy and CDT.As a result,a synergistic tumor growth inhibition was achieved.This work provides a simple method to prepare biomineralized nanoparticles,and offers a general approach for macromolecular drugs delivery via Cu^(2+)-based biomineralization.

A smart MnO_(2)-doped graphene oxide nanosheet for enhanced chemo-photodynamic combinatorial therapy via simultaneous oxygenation and glutathione depletion

The combination of chemotherapy and photodynamic therapy provides a promising approach for enhanced tumor eradication by overcoming the limitations of each individual therapeutic modality.However,tumor is pathologically featured with extreme hypoxia together with the adaptable overexpression of anti-oxidants,such as glutathione(GSH),which greatly restricts the therapeutic efficiency.Here,a combinatorial strategy was designed to simultaneously relieve tumor hypoxia by self-oxygenation and reduce intracellular GSH level to sensitize chemo-photodynamic therapy.In our system,a novel multifunctional nanosystem based on MnO_(2)-doped graphene oxide(GO)was developed to co-load cisplatin(Cis Pt)and a photosensitizer(Ce6).With Mn O_(2)doping,the nanosystem was equipped with intelligent functionalities:(1)catalyzes the decomposition of H_(2)O_(2)into oxygen to relieve the tumor hypoxia;(2)depletes GSH level in tumor cells,and(3)concomitantly generates Mn^(2+)to proceed Fenton-like reaction,all of which contribute to the enhanced anti-tumor efficacy.Meanwhile,the surface hyaluronic acid(HA)modification could facilitate the targeted delivery of the nanosystem into tumor cells,thereby resulting in amplified cellular toxicity,as well as tumor growth inhibition in nude mice model.This work sheds a new light on the development of intelligent nanosystems for synergistic combination therapy via regulating tumor microenvironment.