Stable isotope labeling of nanomaterials for biosafety evaluation and drug development

Quantitative information,such as environmental migration,absorption,biodistribution,biotransformation,and elimination,is fundamental and essential for the nanosafety evaluations of nanomaterials.Due to the complexity of biological and environmental systems,it is challenging to develop quantitative approaches and tools that could characterize intrinsic behaviors of nanomaterials in the organisms.The isotopic tracers are ideal candidates to tune the physical properties of nanomaterials while preserving their chemical properties.In this review article,we summarized the stable isotope labeling methods of nanomaterials for evaluating their environmental and biological effects.The skeleton labeling protocols of carbon nanomaterials and metal/metal oxide nanoparticles were introduced.The advantages and disadvantages of stable isotope labeling were discussed in comparison with other quantitative methods for nanomaterials.The quantitative information of nanomaterials in environmental and biological systems was summarized along with the biosafety data.The benefits for drug development of nanomedicine were analyzed based on the targeting effects,persistent accumulation,and safety.Finally,the challenges and future perspectives of stable isotope labeling in nanoscience and nanotechnology were discussed.

STING and TLR9 agonists synergistically enhance the immunogenicity of SARS-CoV-2 subunit vaccine

Vaccines that are reliable and efficacious are essential in the fight against the COVID-19 pandemic.In this study,we designed a dual-adjuvant system with two pathogen-associated molecular patterns(PAMPs),MnOx and CpG.This system can improve the retention of antigens at the injection site,facilitate pro-inflammatory cytokines secretion,further recruit and activate dendritic cells(DCs).As a result,antigens can be delivered to lymph nodes specifically,and adaptive immunity was strengthened.The immunized group showed an enhanced and broadened humoral and cellular immune response in systemic immunity and lung protection when combined with a tandem repeat-linked dimeric antigen version of the SARS-CoV-2 receptor binding domain(RBDdimer).Remarkably,even with a significant reduction in antigen dosage(three times lower)and a decrease in injection frequencies,our nanovaccine was able to produce the highest neutralizing antibody titers against various mutants.These titers were four-fold higher for the wild-type strain and two-fold higher for both the Beta and Omicron variants in comparison with those elicited by the Alum adjuvant group.In conclusion,our dual-adjuvant formulation presents a promising protein subunit-based candidate vaccine against SARS-CoV-2.

Extracellular Milieu and Membrane Receptor Dual-Driven DNA Nanorobot for Accurate in Vivo Tumor Imaging

Precise diagnostic approaches have great potential in cancer intervention and prognosis.Although diverse DNA nanoprobes have been reported for tumor diagnosis,precise tumor imaging in vivo still encounters a great challenge due to the scarcity of exquisite design methodology.Herein,by assembling three programmable modules on a DNA triangular prism,we engineered a DNA nanorobot for simultaneous recognition of extracellular pH and cancer cell membrane receptor in an intelligent manner.Since the design uses two heterogeneous types of biomarkers as inputs,pH-RE not only could discriminate target tumor cells from similar cell mixtures with a recognition accuracy as high as 98.8%,but also could perform precise tumor imaging in living mice by intravenous injection.We expect that this extracellular pH and membrane receptor dual-driven DNA nanorobot will facilitate the establishment of a novel design paradigm for precise cancer diagnosis and therapy.

A nanoplatform self-assembled by coordination delivers siRNA for lung cancer therapy

The high incidence and mortality of lung cancer have present threaten in front of people all over the world.Researches in clinical trials find that mutations of some genes influence progress of lung cancer directly or indirectly,therefore,some kinds of molecular inhibitors benefit patients in clinical therapy,which helpfully prolong survival time of patients and show great potential in lung cancer therapy.siRNA is a kind of nucleic acid molecules which can silence targeted gene translation through binding to mRNA completely to cure diseases.The delivery of siRNA for cancer therapy mostly can be classified into loading through electrostatic interaction,physical surrounding,and chemically modification.Yet delivering siRNA by coordination has not been reported.This study unprecedently utilizes the coordination between siRNA and Fe^(2+)to form a self-assembly structure in which doxorobicin(DOX) and human serum albumin(HSA) were used to stabilize the whole nanoplatform followed polyethylenimine(PEI) coating.Through the heat incubation strategy,highly loading efficiency for siRNA and DOX was achieved.This nanoplatform with stability and sustain release of drugs exhibited good lysosome escape,gene silencing effect and cytotoxicity which provided new horizon for co-deli very of siRNA and other molecular or protein drugs.

Enrichment of nano delivery platforms for mRNA-based nanotherapeutics

Lipid-based nanoparticles(LNP)have shown significant progress in delivering mRNA for therapeutics,particularly with the success of coronavirus disease 2019(COVID-19)vaccines.However,there are still challenges,such as organ-specific targeting,sustained protein expression,immunogenicity,and storage that need to be addressed.Therefore,there is interest in developing additional nano drug delivery systems(DDS)to complement LNP technology.Some of these include polymer,lipid-polymer hybrid,organic/inorganic hybrid nanostructure,and inorganic nanoparticle.In our opinion,LNP technology may not be suitable for every disease scenario in categories such as infection disease,cancer,pulmonary disease,autoimmune disorders and genetic rare disease(among others).This is because different diseases may require distinct administration routes,doses,and treatment durations,as well as considerations for biological barriers that may lower the efficacy and/or exert safety concern.In this perspective,we will highlight the need and potential for enhancing the diversity of nano delivery platforms for mRNA-based nanotherapeutics.

DNA-mediated coordinative assembly of upconversion hetero-nanostructures for targeted dual-modality imaging of cancer cells

superstructures has enormous potential in material sciences and engineering. Despite the potential,controlled assembly of different kinds of NPs into spatially addressable hybrid configurations still remains a formidable challenge. Herein, we report a simple and universal strategy for DNA-mediated assembly of CdTe quantum dots(QDs) and lanthanide-doped upconversion nanoparticles(UCNPs). Such DNA-QD/UCNPs heterostructures not only maintains both fluorescent properties of QDs and upconversion luminescence behaviors of UCNPs, but also offers a polyvalent DNA surface, allowing for targeted dual-modality imaging of cancer cells using an aptamer. The hetero-assembly mediated by the DNA à inorganic interfacial interaction may provide a scalable way to fabricate hybrid superstructures of both theoretical and practical interests.

Uptake of graphene enhanced the photophosphorylation performed by chloroplasts in rice plants

New and enhanced functions were potentially imparted to the plant organelles after interaction with nanoparticles.In this study,we found that∼44%and∼29%of the accumulated graphene in the rice leaves passively transported to the chloroplasts and thylakoid,respectively,significantly enhanced the fluorescence intensity of chloroplasts,and promoted about 2.4 times higher adenosine triphosphate production than that of controls.The enhancement of graphene on the photophosphorylation was ascribed to two reasons:One is that graphene facilitates the electron transfer process of photosystem II in thylakoid,and the other is that graphene protects the photosystem II against photo-bleaching by acting as a scavenger of reactive oxygen species.Overall,our work here confirmed that graphene translocating in the thylakoid promoted the photosynthetic activity of chloroplast in vivo and in vitro,providing new opportunities for designing biomimetic materials to enhance the solar energy conversion systems,especially for repairing or increasing the photosynthesis activity of the plants grown under stress environment.

Direct site-specific treatment of skin cancer using doxorubicin-loaded nanofibrous membranes

Doxorubicin(DOX) is widely used in cancer therapy. However, its application is sometimes limited by its adverse cardiotoxicity and delivery pathways. In our study, we prepared a topical implantable delivery device for controlled drug release and site-specific treatment. The core region consisted of poly(lactic co-glycolic acid) and poly-caprolactone, whereas the shell region was composed of cross-linked gelatin.DOX was enclosed in the core region of a core-shell nanofiber obtained by electrospinning. This implantable delivery device was implanted on the top of the melanoma in a mouse model, which had shown a DOX-controlled release profile with sustained and sufficient local concentration against melanoma growth in mice with negligible side effects. Compared with the traditional intravenous administration,the implantable device allows precisely localized treatment and therefore can reduce the dose, decrease the injection frequency, and ensure antitumor efficacy associated with lower side effects to normal tissues. Using a coaxial electrospinning process, it is promising to deliver different hydrophobic or hydrophilic drugs for direct tumor site-specific therapy without large systemic doses and minimized systemic toxicity.

Toxicity of manufactured nanomaterials

Manufactured nanomaterials with unique properties have been extensively applied in various indus-trial,agricultural or medical fields.However,some of the properties have been identified to be closely related to nanomaterial toxicity.The"nano-paradox"has aroused concerns over the use and develop-ment of nanotechnology,which makes it difficult for regulatory agencies to regulate nanomaterials.The key to fulfilling proper nanomaterial regulation lies in the adequate understanding of the impact of nanomaterial properties on nano-bio interactions.To this end,we start the present work with a brief intro-duction to nano-bio interactions at different levels.Based on that,how key toxicity-associated properties of manufactured nanomaterials(i.e.,size,shape,chemical composition,surface properties,biocorona formation,agglomeration and/or aggregation state,and biodegradability)impact their toxicokinetics,cel-lular uptake,trafficking and responses,and toxicity mechanisms is deeply explored.Moreover,advanced analytical methods for studying nano-bio interactions are introduced.Furthermore,the current reg-ulatory and legislative frameworks for nanomaterial-containing products in different regions and/or countries are presented.Finally,we propose several challenges facing the nanotoxicology field and their possible solutions to shed light on the safety evaluation of nanomaterials.

Rapidly separable bubble microneedle patch for effective local anesthesia

In cutaneous cosmetology surgery,local injection or coated anesthetics are generally used to provide analgesia at the treatment site to achieve painless operation.Due to the barrier of corneum,topical cream may cause uncertain dosage and delayed analgesia.Local injection has problems such as pain,infection,and misoperation.Therefore,it is necessary to develop a painless and rapid administration method for local anesthesia.Here,a lidocaine/hyaluronic acid bubble microneedle patch(Lido/HA bMNP)was prepared for rapid drug delivery and efficient analgesia.The bubble structure between microneedles(MNs)and the backing layer allowed the MNs to efficiently penetrate into the skin and remove from the backing layer under shear force to rapidly complete the administration.Drugs were quickly released with the dissolution of HA within 15 s,which immediately played an analgesic effect and lasted for 1 h.Lido/HA bMNP could deliver precise doses to the skin in an extremely short time,which had the advantages of convenient operation,high biosafety,rapid onset of analgesia,and reasonable pain relief time.This patch provided an alternative way for local anesthesia and it was a promising transdermal drug delivery method for the realization of high quality and efficiency“painless medical beauty”.

Self-assembly of DNA Nanostructures via Bioinspired Metal Ion Coordination

Despite a growing interest in DNA nanomaterials,their simple synthesis remains a challenge.A simple and general strategy for constructing DNA-based nanomaterials by metal ion coordination is reported.The me-tal-DNA nanoparticles(NPs)could be synthesized with DNA molecules of diverse sequence and various metal ions of intrinsic property,resulting in multifunctional NPs with the combined advantages of both inorganic and DNA building blocks.It is demonstrated that the hybrid metal-DNA NPs could be engineered for magnetic resonance and luminescence imaging,encapsulation of multifarious nucleic acids with controlled ratio,and co-assembly with small drug molecules.Furthermore,because these metal-DNA NPs exhibited enhanced cellular uptake compared to free synthetic DNA,they hold potential for applications in diagnostics and therapeutics.

Engineering Nano−Bio Interfaces from Nanomaterials to Nanomedicines

CONSPECTUS:The nano−bio interface refers to the physical interface between the biological system and nanoscale surface topography,functioning as the barrier between two phases where critical reactions occur.In the last two decades,advances in nanofabrication techniques have heralded a new research area utilizing precisely engineered surfaces and structures to control cell cycles,pathways of metabolism,immune responses,and so forth.At the cellular level,engineered nanomaterials(ENMs)with typical surfaces and structures have been shown to actively affect biological responses,such as stimulating macrophage polarization,monitoring reduction−oxidation equilibrium,and manipulating protease activities via tunable nano−bio interactions.In this Account,we outline our recent progress in surface engineering and structural engineering to improve nano−bio interactions and the performance of nanomedicine.To regulate nanomaterial−molecule and nanomaterial−membrane interactions,we summarize the classical types of nano−bio interaction,extract the essential parameters in nanomaterial surface engineering and structural engineering,and propose effective techniques of surface engineering and structural engineering.We start with identifying the types of dominant interactions between nanomedicines and vital biomolecules:nanonucleic acids,nanoproteins,and nanomembranes.The surface engineering strategies of nano−bio interface tailoring are then arranged into four perspectives:the protein corona(the two modes of protein corona formation and their impacts on altering the affinity profiles of nanomaterials to biological systems),thermoresponsive polymers in superficial modification(passive activation by in situ gelation and active regulation by photothermal conversion),stimulus-induced bonding groups(mediation of nanoparticle aggregation to balance the penetration depth and long-term retention),and inherent surface properties(surface roughness for maximized nano−bio adhesion,surface charge for electrostatic attraction and biological barrier penetration of nanoparticles,and skeleton oxidation to boost nano−bio hydrogen bonding).Structural engineering of nanomaterials occurs by remote manipulation through electron-transfer facilitation(doping,heterojunction,defects,and vacancies)of the nano−bio interaction,following multifaceted solutions that combine multiple surface engineering plans.The scopes and limitation section discusses the prospective problems that can occur when nanomaterials/nanomedicines interact in biological contexts.Because both clinical and laboratory studies have shown the influence of surface topological features on biological responses,the feedback of biological systems to different topographical features of nanomaterials/nanomedicines is essential for us to comprehend the nano−bio interface at the relevant nanometer length scale.For on-demand nano−bio interactions,the discovery provides insight into the rational design of nanomaterials/nanomedicines.

C60(OH)n-loaded nanofibrous membranes protect HaCaT cells from ROS-associated damage

Environmental stress factors could lead to the excess generation of reactive oxygen species（ROS） that induces various forms of skin damage related to oxidative stress. Polyhydroxylated fullerene derivative C（60）（OH）n, acting as an effective agent for prevention of skin aging, is widely used in the lotion and sunscreens in the field of cosmetics, but rarely used in the masks. In this study, we prepared C（60）（OH）n loaded nanofibrous membranes to protect human keratinocyte cells from ROS-associated damage and suppress the elevation of intracellular ROS and Ca（2＋） along with the apoptotic cell death. Two FDAapproved biodegradable polymers, PLGA and PCL, have been used for making the electrospun nanofibers,with C（60）（OH）n added to the polymers as an antioxidant. The nanofibrous membranes with good biocompatibility might be potentially applied in clinical practice to reduce skin aging.