Tailoring the component of protein corona via simple chemistry

In silico bioactivity prediction of proteins interacting with graphene-based nanomaterials guides rational design of biosensor

Graphene-based nanomaterials have attracted significant attention for their potentials in biomedical and biotechnology applications in recent years, owing to the outstanding physical and chemical properties. However, the interaction mechanism and impact on biological activity of macro/micro biomolecules still require more concerns and further research in order to enhance their applicability in biosensors, etc. Herein, an integrated method has been developed to predict the protein bioactivity performance when interacting with nanomaterials for protein-based biosensor. Molecular dynamics simulation and molecular docking technique were consolidated to investigate several nanomaterials: C60 fullerene, single-walled carbon nanotube, pristine graphene and graphene oxide, and their effect when interacting with protein. The adsorption behavior, secondary structure changes and protein bioactivity changes were simulated, and the results of protein activity simulation were verified in combination with atomic force spectrum, circular dichroism spectrum fluorescence and electrochemical experiments. The best quantification alignment between bioactivity obtained by simulation and experiment measurements was further explored. The two proteins, RNase A and Exonuclease III, were regarded as analysis model for the proof of concept, and the prediction accuracy of protein bioactivity could reach up to 0.98. The study shows an easy-to-operate and systematic approach to predict the effects of graphene-based nanomaterials on protein bioactivity, which holds guiding significance for the design of protein-related biosensors. In addition, the proposed prediction model is not limited to carbon-based nanomaterials and can be extended to other types of nanomaterials. This facilitates the rapid, simple, and low-cost selection of efficient and biosafe nanomaterials candidates for protein-related applications in biosensing and biomedical systems.

A comprehensive investigation of the interactions of human serum albumin with polymeric and hybrid nanoparticles

Nanoparticles (NPs) engineered as drug delivery systems continue to make breakthroughs as they offer numerous advantages over free therapeutics. However, the poor understanding of the interplay between the NPs and biomolecules, especially blood proteins, obstructs NP translation to clinics. Nano-bio interactions determine the NPs' in vivo fate, efficacy and immunotoxicity, potentially altering protein function. To fulfill the growing need to investigate nano-bio interactions, this study provides a systematic understanding of two key aspects: (i) protein corona (PC) formation and (ii) NP-induced modifications on protein's structure and stability. A methodology was developed by combining orthogonal techniques to analyze both quantitative and qualitative aspects of nano-bio interactions, using human serum albumin (HSA) as a model protein. Protein quantification via liquid chromatography-mass spectrometry, and capillary zone electrophoresis (CZE) clarified adsorbed protein quantity and stability. CZE further unveiled qualitative insights into HSA forms (native, glycated HSA and cysteinylated), while synchrotron radiation circular dichroism enabled analyzing HSA's secondary structure and thermal stability. Comparative investigations of NP cores (organic vs. hybrid), and shells (with or without polyethylene glycol (PEG)) revealed pivotal factors influencing nano-bio interactions. Polymeric NPs based on poly(lactic-co-glycolic acid) (PLGA) and hybrid NPs based on metal-organic frameworks (nanoMOFs) presented distinct HSA adsorption profiles. PLGA NPs had protein-repelling properties while inducing structural modifications on HSA. In contrast, HSA exhibited a high affinity for nanoMOFs forming a PC altering thereby the protein structure. A shielding effect was gained through PEGylation for both types of NPs, avoiding the PC formation as well as the alteration of unbound HSA structure.

Effect of Nanoparticle Curvature on Its Interaction with Serum Proteins

The size or the curvature of nanoparticles (NPs) plays an important role in regulating the composition of the protein corona. However, the molecular mechanisms of how curvature affects the interaction of NPs with serum proteins still remain elusive. In this study, we employ all-atom molecular dynamics simulations to investigate the interactions between two typical serum proteins and PEGylated Au NPs with three different surface curvatures (0, 0.1, and 0.5 nm-1, respectively). The results show that for proteins with a regular shape, the binding strength between the serum protein and Au NPs decreases with increasing curvature. For irregularly shaped proteins with noticeable grooves, the binding strength between the protein and Au NPs does not change obviously with increasing curvature in the cases of smaller curvature. However, as the curvature continues to increase, Au NPs may act as ligands firmly adsorbed in the protein grooves, significantly enhancing the binding strength. Overall, our findings suggest that the impact of NP curvature on protein adsorption may be nonmonotonic, which may provide useful guidelines for better design of functionalized NPs in biomedical applications.

In vivo Fate of Targeted Drug Delivery Carriers

This review aimed to systematically investigate the intracellular and subcellular fate of various types of targeting carriers. Upon entering the body via intravenous injection or other routes, a targeting carrier that can deliver therapeutic agents initiates their journey. If administered intravenously, the carrier initially faces challenges presented by the blood circulation before reaching specific tissues and interacting with cells within the tissue. At the subcellular level, the car2rier undergoes processes, such as drug release, degradation, and metabolism, through specific pathways. While studies on the fate of 13 types of carriers have been relatively conclusive, these studies are incomplete and lack a comprehensive analysis. Furthermore, there are still carriers whose fate remains unclear, underscoring the need for continuous research. This study highlights the importance of comprehending the in vivo and intracellular fate of targeting carriers and provides valuable insights into the operational mechanisms of different carriers within the body. By doing so, researchers can effectively select appropriate carriers and enhance the successful clinical translation of new formulations.

Mechanistic Insights Behind the Self-Assembly of Human Insulin under the Influence of Surface-Engineered Gold Nanoparticles

Elucidating the underlying principles of amyloid protein self-assembly at nanobio interfaces is extremely challenging due to the diversity in physicochemical properties of nanomaterials and their physical interactions with biological systems. It is, therefore, important to develop nanoscale materials with dynamic features and heterogeneities. In this work, through engineering of hierarchical polyethylene glycol (PEG) structures on gold nanoparticle (GNP) surfaces, tailored nanomaterials with different surface properties and conformations (GNPs-PEG) are created for modulating the self-assembly of a widely studied protein, insulin, under amyloidogenic conditions. Important biophysical studies including thioflavin T (ThT) binding, circular dichroism (CD), surface plasmon resonance (SPR), and atomic force microscopy (AFM) showed that higher-molecular weight GNPs-PEG triggered the formation of amyloid fibrils by promoting adsorption of proteins at nanoparticle surfaces and favoring primary nucleation rate. Moreover, the modulation of fibrillation kinetics reduces the overall toxicity of insulin oligomers and fibrils. In addition, the interaction between the PEG polymer and amyloidogenic insulin examined using MD simulations revealed major changes in the secondary structural elements of the B chain of insulin. The experimental findings provide molecular-level descriptions of how the PEGylated nanoparticle surface modulates protein adsorption and drives the self-assembly of insulin. This facile approach provides a new avenue for systematically altering the binding affinities on nanoscale surfaces by tailoring their topologies for examining adsorption-induced fibrillogenesis phenomena of amyloid proteins. Together, this study suggests the role of nanobio interfaces during surface-induced heterogeneous nucleation as a primary target for designing therapeutic interventions for amyloid-related neurodegenerative disorders.

Engineering the protein corona: Strategies, effects, and future directions in nanoparticle therapeutics

Nanoparticles (NPs) serve as versatile delivery systems for anticancer, antibacterial, and antioxidant agents. The manipulation of protein-NP interactions within biological systems is crucial to the application of NPs in drug delivery and cancer nanotherapeutics. The protein corona (PC) that forms on the surface of NPs is the interface between biomacromolecules and NPs and significantly influences their pharmacokinetics and pharmacodynamics. Upon encountering proteins, NPs undergo surface alterations that facilitate their clearance from circulation by the mononuclear phagocytic system (MPS). PC behavior depends largely on the biological microenvironment and the physicochemical properties of the NPs. This review describes various strategies employed to engineer PC compositions on NP surfaces. The effects of NP characteristics such as size, shape, surface modification and protein precoating on PC performance were explored. In addition, this study addresses these challenges and guides the future directions of this evolving field.

The biomolecular corona of nanomedicines: effects on nanomedicine outcomes and emerging opportunities

Upon administration, nanomedicines adsorb a corona of endogenous biomolecules on their surface, which can affect nanomedicine interactions with cells, targeting, and efficacy. While strategies to reduce protein binding are available, the high selectivity of the adsorbed corona is enabling novel applications, such as for biomarker discovery and rare protein identification. Additionally, the adsorbed molecules can promote interactions with specific cell receptors, thus conferring the nanomedicine new endogenous targeting capabilities. This has been reported for Onpattro, a lipid nanoparticle targeting the hepatocytes via apolipoproteins in its corona. Recently, selective organ-targeting (SORT) nanoparticles have been proposed, which exploit corona-mediated interactions to deliver nanoparticles outside the liver. Strategies for corona seeding and corona engineering are emerging to increase the selectivity of similar endogenous targeting mechanisms.

Modulation of protein-ligand interactions in the presence of ZIF-8: Spectroscopy and molecular dynamics simulation

In this paper, we investigated the protein-ligand interactions in the presence of ZIF-8 using multi-spectroscopic approaches and molecular dynamics simulation. Fluorescence experiments and molecular docking results showed that ZIF-8 did not change the type of quenching and interaction force between ciprofloxacin (CIP) and human serum albumin (HSA), but made the binding constant of HSA-CIP to be smaller, suggesting that ZIF-8 maybe accelerate the dissociation of CIP from HSA-CIP complex. Moreover, the effect of ZIF-8 on the physiological function of HSA was explored. Multi-spectroscopic methods revealed that ZIF-8 did not significantly alter the microenvironment of amino acid groups, but cause a slight decrease in the content of α-helical conformation, and a sparse and flexible structure of the protein backbone. These peculiarities might lead to the diminution of HSA's ability to control drugs. In short, ZIF-8 might enhance drug effect due to affecting the binding of drugs to proteins. However, the present study is only a preliminary investigation of the suitability of ZIF-8 as a drug carrier in vitro, and subsequent in vivo experimental studies will be required to further confirm the idea.

Impact of autologous platelet concentrates on the osseointegration of dental implants

Osseointegration is defined as the direct deposition of bone onto biomaterial devices, most commonly composed from titanium, for the purpose of anchoring dental prostheses. The use of autologous platelet concentrates (APC) has the potential to enhance this process by modifying the interface between the host and the surface of the titanium implant. The rationale is to modify the implant surface and implant-bone interface via "biomimicry," a process whereby the deposition of the host's own proteins and extracellular matrix enhances the biocompatibility of the implant and hence accelerates the osteogenic healing process. This review of the available evidence reporting on the effect of APC on osseointegration explores in vitro laboratory studies of the interaction of APC with different implant surfaces, as well as the in vivo and clinical effects of APC on osseointegration in animal and human studies. The inherent variability associated with using autologous products, namely the unique composition of each individual's blood plasma, as well as the great variety in APC protocols, combination of biomaterials, and clinical/therapeutic application, makes it is difficult to make any firm conclusions about the in vivo and clinical effects of APC on osseointegration. The available evidence suggests that the clinical benefits of adding PRP and the liquid form of L-PRF (liquid fibrinogen) to any implant surface appear to be limited. The application of L-PRF membranes in the osteotomy site, however, may produce positive clinical effects at the early stage of healing (up to 6 weeks), by promoting early implant stability and reducing marginal bone loss, although no positive longer term effects were observed. Careful interpretation and cautious conclusions should be drawn from these findings as there were various limitations in methodology. Future studies should focus on better understanding of the influence of APCs on the biomaterial surface and designing controlled preclinical and clinical studies using standardized APC preparation and application protocols.

Unveiling the challenges of engineered protein corona from the proteins' perspective

It is well known that protein corona affects the "biological identity" of nanoparticles (NPs), which has been seen as both a challenge and an opportunity. Approaches have moved from avoiding protein adsorption to trying to direct it, taking advantage of the formation of a protein corona to favorably modify the pharmacokinetic parameters of NPs. Although promising, the results obtained with engineered NPs still need to be completely understood. While much effort has been put into understanding how the surface of nanomaterials affects protein absorption, less is known about how proteins can affect corona formation due to their specific physicochemical properties. This review addresses this knowledge gap, examining key protein factors influencing corona formation, highlighting current challenges in studying protein-protein interactions, and discussing future perspectives in the field.

Modulating the toxicity of engineered nanoparticles by controlling protein corona formation: Recent advances and future prospects

With the rapid development and widespread application of engineered nanoparticles (ENPs), understanding the fundamental interactions between ENPs and biological systems is essential to assess and predict the fate of ENPs in vivo. When ENPs are exposed to complex physiological environments, biomolecules quickly and inevitably adsorb to ENPs to form a biomolecule corona, such as a protein corona (PC). The formed PC has a significant effect on the physicochemical properties of ENPs and gives them a brand new identity in the biological environment, which determines the subsequent ENP-cell/tissue/organ interactions. Controlling the formation of PCs is therefore of utmost importance to accurately predict and optimize the behavior of ENPs within living organisms, as well as ensure the safety of their applications. In this review, we provide an overview of the fundamental aspects of the PC, including the formation mechanism, composition, and frequently used characterization techniques. We comprehensively discuss the potential impact of the PC on ENP toxicity, including cytotoxicity, immune response, and so on. Additionally, we summarize recent advancements in manipulating PC formation on ENPs to achieve the desired biological outcomes. We further discuss the challenges and prospects, aiming to provide valuable insights for a better understanding and prediction of ENP behaviors in vivo, as well as the development of low-toxicity ENPs.

Surface Chemistry of Biologically Active Reducible Oxide Nanozymes

Reducible metal oxide nanozymes (rNZs) are a subject of intense recent interest due to their catalytic nature, ease of synthesis, and complex surface character. Such materials contain surface sites which facilitate enzyme-mimetic reactions via substrate coordination and redox cycling. Further, these surface reactive sites are shown to be highly sensitive to stresses within the nanomaterial lattice, the physicochemical environment, and to processing conditions occurring as part of their syntheses. When administered in vivo, a complex protein corona binds to the surface, redefining its biological identity and subsequent interactions within the biological system. Catalytic activities of rNZs each deliver a differing impact on protein corona formation, its composition, and in turn, their recognition, and internalization by host cells. Improving the understanding of the precise principles that dominate rNZ surface-biomolecule adsorption raises the question of whether designer rNZs can be engineered to prevent corona formation, or indeed to produce "custom" protein coronas applied either in vitro, and preadministration, or formed immediately upon their exposure to body fluids. Here, fundamental surface chemistry processes and their implications in rNZ material performance are considered. In particular, material structures which inform component adsorption from the application environment, including substrates for enzyme-mimetic reactions are discussed.

Regulating protein corona on nanovesicles by glycosylated polyhydroxy polymer modification for efficient drug delivery

The dynamic protein corona formed on nanocarriers has been revealed to strongly affect their in vivo behaviors. Precisely manipulating the formation of protein corona on nanocarriers may provide an alternative impetus for specific drug delivery. Herein, we explore the role of glycosylated polyhydroxy polymer-modified nanovesicles (CP-LVs) with different amino/hydroxyl ratios in protein corona formation and evolution. CP-LVs with an amino/hydroxyl ratio of approximately 0.4 (CP1-LVs) are found to efficiently suppress immunoglobulin adsorption in blood and livers, resulting in prolonged circulation. Moreover, CP1-LVs adsorb abundant tumor distinctive proteins, such as CD44 and osteopontin in tumor interstitial fluids, mediating selective tumor cell internalization. The proteins corona transformation specific to the environment appears to be affected by the electrostatic interaction between CP-LVs and proteins with diverse isoelectric points. Benefiting from surface modification-mediated protein corona regulation, paclitaxel-loaded CP1-LVs demonstrate superior antitumor efficacy to PEGylated liposomes. Our work offers a perspective on rational surface-design of nanocarriers to modulate the protein corona formation for efficient drug delivery.

Molecular Modeling of the Fluorination Effect on the Penetration of Nanoparticles across Lipid Bilayers

The fluorinated decorations have recently been widely used in many biomedical applications. However, the potential mechanism of the fluorination effect on the cellular delivery of nanoparticles (NPs) still remains elusive. In this work, we systemically explore the penetration of a perfluoro-octanethiol-coated gold NP (PF-Au NP) and, for comparison, an octanethiol-coated gold NP (OT-Au NP) across lipid bilayers. We also investigated the effect of these two types of NPs on the properties of lipid bilayers. Our findings indicate that the lipid type and the surface tension of the lipid bilayer significantly impact the penetration capabilities of the fluorinated gold NP. By examining the distribution of ligands on the surface of the two types of NPs in water and during the penetration process, we unveil their distinct penetration characteristics. Specifically, the PF-Au NP exhibits amphiphobic behavior (both hydrophobic and lipophobic), while the OT-Au NP exhibits solely hydrophobic characteristics. Finally, we observe that the penetration capabilities can be increased by adjusting the degree of fluorination of the ligands on the NP surface. Overall, this study provides useful physical insights into the unique properties of the fluorinated decorations in NP permeation.

Development of nano-delivery systems for loaded bioactive compounds: using molecular dynamics simulations

Over the past decade, a remarkable surge in the development of functional nano-delivery systems loaded with bioactive compounds for healthcare has been witnessed. Notably, the demanding requirements of high solubility, prolonged circulation, high tissue penetration capability, and strong targeting ability of nanocarriers have posed interdisciplinary research challenges to the community. While extensive experimental studies have been conducted to understand the construction of nano-delivery systems and their metabolic behavior in vivo, less is known about these molecular mechanisms and kinetic pathways during their metabolic process in vivo, and lacking effective means for high-throughput screening. Molecular dynamics (MD) simulation techniques provide a reliable tool for investigating the design of nano-delivery carriers encapsulating these functional ingredients, elucidating the synthesis, translocation, and delivery of nanocarriers. This review introduces the basic MD principles, discusses how to apply MD simulation to design nanocarriers, evaluates the ability of nanocarriers to adhere to or cross gastrointestinal mucosa, and regulates plasma proteins in vivo. Moreover, we presented the critical role of MD simulation in developing delivery systems for precise nutrition and prospects for the future. This review aims to provide insights into the implications of MD simulation techniques for designing and optimizing nano-delivery systems in the healthcare food industry.

Effect of surface functionalization on DNA sequencing using MXene-based nanopores

As one of the most promising types of label-free nanopores has great potential for DNA sequencing via fast detection of different DNA bases. As one of the most promising types of label-free nanopores, two-dimensional nanopore materials have been developed over the past two decades. However, how to detect different DNA bases efficiently and accurately is still a challenging problem. In the present work, the translocation of four homogeneous DNA strands (i.e., poly(A)20, poly(C)20, poly(G)20, and poly(T)20) through two-dimensional transition-metal carbide (MXene) membrane nanopores with different surface terminal groups is investigated via all-atom molecular dynamics simulations. Interestingly, it is found that the four types of bases can be distinguished by different ion currents and dwell times when they are transported through the Ti3C2(OH)2 nanopore. This is mainly attributed to the different orientation and position distributions of the bases, the hydrogen bonding inside the MXene nanopore, and the interaction of the ssDNA with the nanopore. The present study enhances the understanding of the interaction between DNA strands and MXene nanopores with different functional groups, which may provide useful guidelines for the design of MXene-based devices for DNA sequencing in the future.

Enantioselective Antiviral Activities of Chiral Zinc Oxide Nanoparticles

Chiral nanoparticles (C-NPs) play a crucial role in biomedical applications, especially in their biological effects on cytotoxicity and metabolism. However, there are rare reports about the antivirus property of C-NPs and their working mechanism. Here, three different types of chiral ZnO NPs (l-ZnO, d-ZnO, and dl-ZnO) were prepared as enantioselective antivirals. Biocompatibility test results showed that the three different chiral ZnO NPs varied significantly in cytotoxicity. Evaluation of their effects against porcine reproductive and respiratory syndrome virus (PRRSV) indicated that compared with d-ZnO and dl-ZnO NPs, l-ZnO NPs exhibited stronger anti-PRRSV activity due to their higher cognate cell adhesion and uptake. Furthermore, the high concentration of l-ZnO NPs can obviously reduce cellular reactive oxygen species (ROS) in MARC-145 cells, thus effectively preventing PRRSV-induced oxidative damage. This study demonstrated the outstanding antiviral properties of l-ZnO NPs, which may facilitate the development and application of C-NPs in antiviral drugs and tissue engineering.

Advances in Targeting Drug Biological Carriers for Enhancing Tumor Therapy Efficacy

Chemotherapy drugs continue to be the main component of oncology treatment research and have been proven to be the main treatment modality in tumor therapy. However, the poor delivery efficiency of cancer therapeutic drugs and their potential off-target toxicity significantly limit their effectiveness and extensive application. The recent integration of biological carriers and functional agents is expected to camouflage synthetic biomimetic nanoparticles for targeted delivery. The promising candidates, including but not limited to red blood cells and their membranes, platelets, tumor cell membrane, bacteria, immune cell membrane, and hybrid membrane are typical representatives of biological carriers because of their excellent biocompatibility and biodegradability. Biological carriers are widely used to deliver chemotherapy drugs to improve the effectiveness of drug delivery and therapeutic efficacy in vivo, and tremendous progress is made in this field. This review summarizes recent developments in biological vectors as targeted drug delivery systems based on microenvironmental stimuli-responsive release, thus highlighting the potential applications of target drug biological carriers. The review also discusses the possibility of clinical translation, as well as the exploitation trend of these target drug biological carriers.

Formation and detection of biocoronas in the food industry and their fate in the human body

The rapid advancement of nanotechnology has opened up new avenues for applications in all stages of the food industry. Over the past decade, extensive research has emphasized that when nanoparticles (NPs) enter organisms, they spontaneously adsorbed biomolecules, leading to the formation of biocorona. This paper provided a detailed review of the process of biocorona formation in the food industry, including their classification and influencing factors. Additionally, various characterization methods to investigated the morphology and structure of biocoronas were introduced. As a real state of food industry nanoparticles in biological environments, the biocorona causes structural transformations of biomolecules bound to NPs, thus affecting their fate in the body. It can either promote or inhibit enzyme activity in the human environment, and may also positively or negatively affect the cellular uptake and toxicity of NPs. Since NPs present in the food industry will inevitably enter the human body, further investigations on biocoronas will offer valuable insights and perspectives on the safety of incorporating more NPs into the food industry.

Size-Dependent In Vivo Transport of Nanoparticles: Implications for Delivery, Targeting, and Clearance

Understanding the in vivo transport of nanoparticles provides guidelines for designing nanomedicines with higher efficacy and fewer side effects. Among many factors, the size of nanoparticles plays a key role in controlling their in vivo transport behaviors due to the existence of various physiological size thresholds within the body and size-dependent nano-bio interactions. Encouraged by the evolving discoveries of nanoparticle-size-dependent biological effects, we believe that it is necessary to systematically summarize the size-scaling laws of nanoparticle transport in vivo. In this review, we summarized the size effect of nanoparticles on their in vivo transport along their journey in the body: begin with the administration of nanoparticles via different delivery routes, followed by the targeting of nanoparticles to intended tissues including tumors and other organs, and eventually clearance of nanoparticles through the liver or kidneys. We outlined the tools for investigating the in vivo transport of nanoparticles as well. Finally, we discussed how we may leverage the size-dependent transport to tackle some of the key challenges in nanomedicine translation and also raised important size-related questions that remain to be answered in the future.

Competition of opsonins and dysopsonins on the nanoparticle surface

The biological behavior and fate of nanoparticles are dependent on their retention time in the blood circulation system. The protein corona components, especially opsonins, and dysopsonins, adsorbed on the nanoparticle surface determine their blood circulation time. The protein corona formation is a dynamic process that involves the competition between different proteins to be adsorbed on the nanoparticles. Therefore, studying how proteins compete and are oriented on the nanoparticle surface is essential. We hypothesized that the presence of opsonins (immunoglobulin (IgG)) might affect the adsorption of dysopsonins (human serum albumin (HSA)) and vice versa. Using the molecular dynamics simulations, we showed that the adsorption of HSA on the GO surface after the IgG adsorption is more probable than the opposite order of adsorption. It was also observed that the higher lateral diffusion of the HSA compared to the IgG helped the system reach a more stable configuration while the initial adsorption of the HSA limits the lateral diffusion of IgG. Therefore, replacing IgG adsorbed on the GO surface with HSA is plausible while the reverse process is less likely to occur. This study revealed that albumin might extend the blood circulation time of GO by replacing opsonins (IgG).

Application of Nanoparticles in Cancer Treatment: A Concise Review

Timely diagnosis and appropriate antitumoral treatments remain of utmost importance, since cancer remains a leading cause of death worldwide. Within this context, nanotechnology offers specific benefits in terms of cancer therapy by reducing its adverse effects and guiding drugs to selectively target cancer cells. In this comprehensive review, we have summarized the most relevant novel outcomes in the range of 2010-2023, covering the design and application of nanosystems for cancer therapy. We have established the general requirements for nanoparticles to be used in drug delivery and strategies for their uptake in tumor microenvironment and vasculature, including the reticuloendothelial system uptake and surface functionalization with protein corona. After a brief review of the classes of nanovectors, we have covered different classes of nanoparticles used in cancer therapies. First, the advances in the encapsulation of drugs (such as paclitaxel and fisetin) into nanoliposomes and nanoemulsions are described, as well as their relevance in current clinical trials. Then, polymeric nanoparticles are presented, namely the ones comprising poly lactic-co-glycolic acid, polyethylene glycol (and PEG dilemma) and dendrimers. The relevance of quantum dots in bioimaging is also covered, namely the systems with zinc sulfide and indium phosphide. Afterwards, we have reviewed gold nanoparticles (spheres and anisotropic) and their application in plasmon-induced photothermal therapy. The clinical relevance of iron oxide nanoparticles, such as magnetite and maghemite, has been analyzed in different fields, namely for magnetic resonance imaging, immunotherapy, hyperthermia, and drug delivery. Lastly, we have covered the recent advances in the systems using carbon nanomaterials, namely graphene oxide, carbon nanotubes, fullerenes, and carbon dots. Finally, we have compared the strategies of passive and active targeting of nanoparticles and their relevance in cancer theranostics. This review aims to be a (nano)mark on the ongoing journey towards realizing the remarkable potential of different nanoparticles in the realm of cancer therapeutics.

'Passive' nanoparticles for organ-selective systemic delivery: design, mechanism and perspective

Nanotechnology has shown tremendous success in the drug delivery field for more effective and safer therapy, and has recently enabled the clinical approval of RNA medicine, a new class of therapeutics. Various nanoparticle strategies have been developed to improve the systemic delivery of therapeutics, among which surface modification of targeting ligands on nanoparticles has been widely explored for 'active' delivery to a specific organ or diseased tissue. Meanwhile, compelling evidence has recently been reported that organ-selective targeting may also be achievable by systemic administration of nanoparticles without surface ligand modification. In this Review, we highlight this unique set of 'passive' nanoparticles and their compositions and mechanisms for organ-selective delivery. In particular, the lipid-based, polymer-based, and biomimetic nanoparticles with tropism to different specific organs after intravenous administration are summarized. The underlying mechanisms (e.g., protein corona and size effect) of these nanosystems for organ selectivity are also extensively discussed. We further provide perspectives on the opportunities and challenges in this exciting area of organ-selective systemic nanoparticle delivery.

Covalent organic frameworks: linkage types, synthetic methods and bio-related applications

Covalent organic frameworks (COFs) are composed of small organic molecules linked via covalent bonds, which have tunable mesoporous structure, good biocompatibility and functional diversities. These excellent properties make COFs a promising candidate for constructing biomedical nanoplatforms and provide ample opportunities for nanomedicine development. A systematic review of the linkage types and synthesis methods of COFs is of indispensable value for their biomedical applications. In this review, we first summarize the types of various linkages of COFs and their corresponding properties. Then, we highlight the reaction temperature, solvent and reaction time required by different synthesis methods and show the most suitable synthesis method by comparing the merits and demerits of various methods. To appreciate the cutting-edge research on COFs in bioscience technology, we also summarize the bio-related applications of COFs, including drug delivery, tumor therapy, bioimaging, biosensing and antimicrobial applications. We hope to provide insight into the interdisciplinary research on COFs and promote the development of COF nanomaterials for biomedical applications and their future clinical translations.

The interplay between lysosome, protein corona and biological effects of cationic carbon dots: Role of surface charge titratability

Carbon dots (CDs) are nanoparticles (NPs) with potential applications in the biomedical field. When in contact with biological fluids, most NPs are covered by a protein corona. As well, upon cell entry, most NP are sequestered in the lysosome. However, the interplay between the lysosome, the protein corona and the biological effects of NPs is still poorly understood. In this context, we investigated the role of the lysosome in the toxicological responses evoked by four cationic CDs exhibiting protonatable or non-protonatable amine groups at their surface, and the associated changes in the CD protein corona. The four CDs accumulated in the lysosome and led to lysosomal swelling, loss lysosome integrity, cathepsin B activation, NLRP3 inflammasome activation, and cell death by pyroptosis in a human macrophage model, but with a stronger effect for CDs with titratable amino groups. The protein corona formed around CDs in contact with serum partially dissociated under lysosomal conditions with subsequent protein rearrangement, as assessed by quantitative proteomic analysis. The residual protein corona still contained binding proteins, catalytic proteins, and proteins involved in the proteasome, glycolysis, or PI3k-Akt KEGG pathways, but with again a more pronounced effect for CDs with titratable amino groups. These results demonstrate an interplay between lysosome, protein corona and biological effects of cationic NPs in link with the titratability of NP surface charges.

The role of protein corona on nanodrugs for organ-targeting and its prospects of application

Nowadays, nanodrugs become a hotspot in the high-end medical field. They have the ability to deliver drugs to reach their destination more effectively due to their unique properties and flexible functionalization. However, the fate of nanodrugs in vivo is not the same as those presented in vitro, which indeed influenced their therapeutic efficacy in vivo. When entering the biological organism, nanodrugs will first come into contact with biological fluids and then be covered by some biomacromolecules, especially proteins. The proteins adsorbed on the surface of nanodrugs are known as protein corona (PC), which causes the loss of prospective organ-targeting abilities. Fortunately, the reasonable utilization of PC may determine the organ-targeting efficiency of systemically administered nanodrugs based on the diverse expression of receptors on cells in different organs. In addition, the nanodrugs for local administration targeting diverse lesion sites will also form unique PC, which plays an important role in the therapeutic effect of nanodrugs. This article introduced the formation of PC on the surface of nanodrugs and summarized the recent studies about the roles of diversified proteins adsorbed on nanodrugs and relevant protein for organ-targeting receptor through different administration pathways, which may deepen our understanding of the role that PC played on organ-targeting and improve the therapeutic efficacy of nanodrugs to promote their clinical translation.

Interaction of Iron Oxide Nanoparticles with Macrophages Is Influenced Distinctly by "Self" and "Non-Self" Biological Identities

Upon contact with biological fluids like serum, a protein corona (PC) complex forms on iron oxide nanoparticles (IONPs) in physiological environments and the proteins it contains influence how IONPs act in biological systems. Although the biological identity of PC-IONP complexes has often been studied in vitro and in vivo, there have been inconsistent results due to the differences in the animal of origin, the type of biological fluid, and the physicochemical properties of the IONPs. Here, we identified differences in the PC composition when it was derived from the sera of three species (bovine, murine, or human) and deposited on IONPs with similar core diameters but with different coatings [dimercaptosuccinic acid (DMSA), dextran (DEX), or 3-aminopropyl triethoxysilane (APS)], and we assessed how these differences influenced their effects on macrophages. We performed a comparative proteomic analysis to identify common proteins from the three sera that adsorb to each IONP coating and the 10 most strongly represented proteins in PCs. We demonstrated that the PC composition is dependent on the origin of the serum rather than the nature of the coating. The PC composition critically affects the interaction of IONPs with macrophages in self- or non-self identity models, influencing the activation and polarization of macrophages. However, such effects were more consistent for DMSA-IONPs. As such, a self biological identity of IONPs promotes the activation and M2 polarization of murine macrophages, while a non-self biological identity favors M1 polarization, producing larger quantities of ROS. In a human context, we observed the opposite effect, whereby a self biological identity of DMSA-IONPs promotes a mixed M1/M2 polarization with an increase in ROS production. Conversely, a non-self biological identity of IONPs provides nanoparticles with a stealthy character as no clear effects on human macrophages were evident. Thus, the biological identity of IONPs profoundly affects their interaction with macrophages, ultimately defining their biological impact on the immune system.

Physico-Chemical Approaches to Investigate Surface Hydroxyls as Determinants of Molecular Initiating Events in Oxide Particle Toxicity

The study of molecular recognition patterns is crucial for understanding the interactions between inorganic (nano)particles and biomolecules. In this review we focus on hydroxyls (OH) exposed at the surface of oxide particles (OxPs) which can play a key role in molecular initiating events leading to OxPs toxicity. We discuss here the main analytical methods available to characterize surface OH from a quantitative and qualitative point of view, covering thermogravimetry, titration, ζ potential measurements, and spectroscopic approaches (NMR, XPS). The importance of modelling techniques (MD, DFT) for an atomistic description of the interactions between membranes/proteins and OxPs surfaces is also discussed. From this background, we distilled a new approach methodology (NAM) based on the combination of IR spectroscopy and bioanalytical assays to investigate the molecular interactions of OxPs with biomolecules and membranes. This NAM has been already successfully applied to SiO₂ particles to identify the OH patterns responsible for the OxPs' toxicity and can be conceivably extended to other surface-hydroxylated oxides.

GPP-TSAIII nanocomposite hydrogel-based photothermal ablation facilitates melanoma therapy

BACKGROUND

Photothermal therapy (PTT) is a promising cancer treatment, but its application is limited by low photoconversion efficiency. In this study, we aimed to develop a novel graphene oxide (GO)-based nanocomposite hydrogel to improve the bioavailability of timosaponin AIII (TSAIII) while maximizing PTT efficacy and enhancing the antitumor effect.

METHODS

GO was modified via physical cross-linking with polyvinyl alcohol. The pore structure of the gel was adjusted by repeated freeze-thawing and the addition of polyethylene glycol 2000 to obtain a nanocomposite hydrogel (GPP). The GPP loaded with TSAIII constituted a GPP-TSAIII drug delivery system, and its efficacy was evaluated by in vitro cytotoxicity, apoptosis, migration, and uptake analyses, and in vivo antitumor studies.

RESULTS

The encapsulation rate of GPP-TSAIII was 66.36 ± 3.97%, with slower in vitro release and higher tumor cell uptake (6.4-fold) compared to TSAIII. GPP-TSAIII in combination with PTT showed better bioavailability and antitumor effects in vivo than did TSAIII, with a 1.9-fold higher tumor suppression rate than the TSAIII group.

CONCLUSIONS

GPP is a potential vehicle for delivery of TSAIII-like poor water-soluble anticancer drugs. The innovative PTT co-delivery system may serve as a safe and effective melanoma treatment platform for further anticancer translational purposes.

Converting Nanotoxicity Data to Information Using Artificial Intelligence and Simulation

Decades of nanotoxicology research have generated extensive and diverse data sets. However, data is not equal to information. The question is how to extract critical information buried in vast data streams. Here we show that artificial intelligence (AI) and molecular simulation play key roles in transforming nanotoxicity data into critical information, i.e., constructing the quantitative nanostructure (physicochemical properties)-toxicity relationships, and elucidating the toxicity-related molecular mechanisms. For AI and molecular simulation to realize their full impacts in this mission, several obstacles must be overcome. These include the paucity of high-quality nanomaterials (NMs) and standardized nanotoxicity data, the lack of model-friendly databases, the scarcity of specific and universal nanodescriptors, and the inability to simulate NMs at realistic spatial and temporal scales. This review provides a comprehensive and representative, but not exhaustive, summary of the current capability gaps and tools required to fill these formidable gaps. Specifically, we discuss the applications of AI and molecular simulation, which can address the large-scale data challenge for nanotoxicology research. The need for model-friendly nanotoxicity databases, powerful nanodescriptors, new modeling approaches, molecular mechanism analysis, and design of the next-generation NMs are also critically discussed. Finally, we provide a perspective on future trends and challenges.

Peptide-Based Nanoparticles for Systemic Extrahepatic Delivery of Therapeutic Nucleotides

Peptide-based nanoparticles (PBN) for nucleotide complexation and targeting of extrahepatic diseases are gaining recognition as potent pharmaceutical vehicles for fine-tuned control of protein production (up- and/or down-regulation) and for gene delivery. Herein, we review the principles and mechanisms underpinning self-assembled formation of PBN, cellular uptake, endosomal release, and delivery to extrahepatic disease sites after systemic administration. Selected examples of PBN that have demonstrated recent proof of concept in disease models in vivo are summarized to offer the reader a comparative view of the field and the possibilities for clinical application.

Time Evolution of Ultrasmall Gold Nanoparticle-Protein Interactions

To date, much effort has been devoted toward the study of protein corona formation onto large gold nanoparticles (GNPs). However, the protein corona concept breaks down for GNPs in the ultrasmall size regime (<3 nm), and, as a result, our understanding of ultrasmall GNP (usGNP)-protein interactions remains incomplete. Herein, we used anionic usGNPs and six different proteins as model systems to systematically investigate usGNP-protein interactions, with particular focus on the time evolution and long-term behavior of complex formation. The different proteins comprised chymotrypsin (Cht), trypsin (Try), thrombin (Thr), serum albumin (HSA), cytochrome c (Cyt c), and factor XII (FXII). We used a range of biochemical and biophysical methods to estimate binding affinities, determine the effects of usGNPs on protein structure and function, assess the reversibility of any protein structural and functional changes, and evaluate usGNP-protein complex stability. Among the main findings, we observed that prolonged (24 h)─but not short-term (10 min)─interactions between proteins and usGNPs permanently altered protein function, including enzyme activities (Try, Thr, and FXIIa), peroxidase-like activity (Cyt c), and ligand-binding properties (HSA). Remarkably, this occurred without any large-scale loss of the native global conformation, implying time-dependent effects of usGNPs on local protein conformation or dynamics. We also found that both short-(10 min) and long-term (24 h) interactions between proteins and usGNPs yielded short-lived complexes, i.e., there was no time-dependent "hardening" of the interactions at the binding interface as usually seen with large GNPs. The present study increases our fundamental understanding of nano-bio interactions in the ultrasmall size regime, which may assist the safe and effective translation of usGNPs into the clinic.

Protein corona and exosomes: new challenges and prospects

Recent advances in extracellular vesicle (EVs) detection and isolation methods have led to the development of novel therapeutic modalities. Among different types of EVs, exosomes (Exos) can transfer different signaling biomolecules and exhibit several superior features compared to whole-cell-based therapies. Therapeutic factors are normally loaded into the Exo lumen or attached to their surface for improving the on-target delivery rate and regenerative outcomes. Despite these advantages, there are several limitations in the application of Exos in in vivo conditions. It was suggested that a set of proteins and other biological compounds are adsorbed around Exos in aqueous phases and constitute an external layer named protein corona (PC). Studies have shown that PC can affect the physicochemical properties of synthetic and natural nanoparticles (NPs) after introduction in biofluids. Likewise, PC is generated around EVs, especially Exos in in vivo conditions. This review article is a preliminary attempt to address the interfering effects of PC on Exo bioactivity and therapeutic effects. Video Abstract.

Characterization of the Protein Corona of Three Chairside Hemoderivatives on Melt Electrowritten Polycaprolactone Scaffolds

In tissue engineering, the relationship between a biomaterial surface and the host's immune response during wound healing is crucial for tissue regeneration. Despite hemoderivative functionalization of biomaterials becoming a common tissue-engineering strategy for enhanced regeneration, the characteristics of the protein-biomaterial interface have not been fully elucidated. This study characterized the interface formed by the adsorbed proteins from various hemoderivatives with pristine and calcium phosphate (CaP)-coated polycaprolactone (PCL) melt electrowritten scaffolds. PCL scaffolds were fabricated by using melt electrospinning writing (MEW). Three hemoderivatives (pure platelet-rich plasma (P-PRP), leucocyte platelet-rich plasma (L-PRP) and injectable platelet-rich fibrin (i-PRF)) and total blood PLASMA (control) were prepared from ovine blood. Hemoderivatives were characterized via SEM/EDX, cross-linking assay, weight loss, pH and protein quantification. The interface between PCL/CaP and hemoderivative was examined via FTIR, XPS and electrophoresis. i-PRF/PCL-CaP (1653 cm^-1), PLASMA/PCL-CaP (1652 cm^-1) and i-PRF/PCL (1651 cm^-1) demonstrated a strong signal at the Amide I region. PLASMA and i-PRF presented similar N1s spectra, with most of the nitrogen involved in N-C=O bonds (≈400 eV). i-PRF resulted in higher adsorption of low molecular weight (LMW) proteins at 60 min, while PLASMA exhibited the lowest adsorption. L-PRP and P-PRP had a similar pattern of protein adsorption. The characteristics of biomaterial interfaces can be customized, thus creating a specific hemoderivative-defined layer on the PCL surface. i-PRF demonstrated a predominant adsorption of LMW proteins. Further investigation of hemoderivative functionalized biomaterials is required to identify the differential protein corona composition, and the resultant immune response and regenerative capacity.

Sustained release of GLP-1 analog from γ-PGA-PAE copolymers for management of type 2 diabetes

GLP-1 has been clinically exploited for treating type 2 diabetes, while its short circulation half-life requires multiple daily injections to maintain effective glycemic control, thus limiting its widespread application. Here we developed a drug delivery system based on self-assembling polymer-amino acid conjugates (γ-PGA-PAE) to provide sustained release of GLP-1 analog (DLG3312). The DLG3312 loaded γ-PGA based nanoparticles (DLG3312@NPs) exhibited a spherical shape with a good monodispersity under transmission electron microscope (TEM) observation. The DLG3312 encapsulation was optimized, and the loading efficiency was as high as 78.4 ± 2.2 %. The transformation of DLG3312@NPs to network structures was observed upon treatment with the fresh serum, resulting in a sustained drug release. The in vivo long-term hypoglycemic assays indicated that DLG3312@NPs significantly reduced blood glucose and glycosylated hemoglobin level. Furthermore, DLG3312@NPs extended the efficacy of DLG3312, leading to a decrease in the dosing schedule that from once a day to once every other day. This approach combined the molecular and materials engineering strategies that offered a unique solution to maximize the availability of anti-diabetic drug and minimize its burdens to type 2 diabetic patients.

Antitumor therapy for breast cancer: Focus on tumor-associated macrophages and nanosized drug delivery systems

BACKGROUND

In breast cancer (BC), tumor-associated macrophages (TAMs) are an important component of the tumor microenvironment and are closely related to poor prognosis. A growing number of studies have focused on the role of TAMs in BC progression and therapeutic strategies targeting TAMs. As an emerging treatment, the application of nanosized drug delivery systems (NDDSs) in the treatment of BC by targeting TAMs has attracted much attention.

AIMS

This review is to summarize the characteristics and treatment strategies targeting TAMs in BC and to clarify the applications of NDDSs targeting TAMs in the treatment of BC by targeting TAMs.

MATERIALS & METHODS

The existing results related to characteristics of TAMs in BC, BC treatment strategies by targeting TAMs, and the applications of NDDSs in these strategies are described. Through analyzing these results, the advantages and disadvantages of the treatment strategies using NDDSs are discussed, which could provide advices on designing NDDSs for BC treatment.

RESULTS

TAMs are one of the most prominent noncancer cell types in BC. TAMs not only promote angiogenesis, tumor growth and metastasis but also lead to therapeutic resistance and immunosuppression. Mainly four strategies have been used to target TAMs for BC therapy, which include depleting macrophages, blocking recruitment, reprogramming to attain an anti-tumor phenotype, and increasing phagocytosis. Since NDDSs can efficiently deliver drugs to TAMs with low toxicity, they are promising approaches for targeting TAMs in tumor therapy. NDDSs with various structures can deliver immunotherapeutic agents and nucleic acid therapeutics to TAMs. In addition, NDDSs can realize combination therapies.

DISCUSSION

TAMs play a critical role in the progression of BC. An increasing number of strategies have been proposed to regulate TAMs. Compared with free drugs, NDDSs targeting TAMs improve drug concentration, reduce toxicity and realize combination therapies. However, in order to achieve better therapeutic efficacy, there are still some disadvantages that need to be considered in the design of NDDSs.

CONCLUSION

TAMs play an important role in the progression of BC, and targeting TAMs is a promising strategy for BC therapy. In particular, NDDSs targeting TAMs have unique advantages and are potential treatments for BC.

Advanced strategies to evade the mononuclear phagocyte system clearance of nanomaterials

Nanomaterials are promising carriers to improve the bioavailability and therapeutic efficiency of drugs by providing preferential drug accumulation at their sites of action, but their delivery efficacy is severely limited by a series of biological barriers, especially the mononuclear phagocytic system (MPS)-the first and major barrier encountered by systemically administered nanomaterials. Herein, the current strategies for evading the MPS clearance of nanomaterials are summarized. First, engineering nanomaterials methods including surface modification, cell hitchhiking, and physiological environment modulation to reduce the MPS clearance are explored. Second, MPS disabling methods including MPS blockade, suppression of macrophage phagocytosis, and macrophages depletion are examined. Last, challenges and opportunities in this field are further discussed.

The effects of serum albumin pre-adsorption of nanoparticles on protein corona and membrane interaction: A molecular simulation study

As a platform to deliver imaging and therapeutic agents to targeted sites in vivo, nanoparticles (NPs) have widespread applications in diagnosis and treatment of cancer. However, the poor in vivo delivery efficiency of nanoparticles limits its potential for further application. Once enter the physiological environment, nanoparticles immediately interact with proteins and form protein corona, which changes the physicochemical properties of nanoparticle surface and further affects their transport. In this study, we performed molecular dynamics simulations to study the adsorption mechanism of nanoparticles with various surface modifications and different proteins (e.g., human serum albumin, complement protein C3b), and their interactions with cell membrane. The results show that protein human serum albumin prefers to interact with hydrophobic and positively charged nanoparticles, while the protein C3b prefers the hydrophobic and charged nanoparticles. The pre-adsorption of human serum albumin on the nanoparticle surface obviously decreases the interaction of nanoparticle with C3b. Furthermore, the high amount of protein pre-adsorption could decrease the probability of nanoparticle-membrane interaction. These results indicate that appropriate modification of nanoparticles with protein provides nanoparticles with better capability of targeting, which could be used to guide nanoparticle design and improve transport efficiency.

Protein corona: Friend or foe? Co-opting serum proteins for nanoparticle delivery

For systemically delivered nanoparticles to reach target tissues, they must first circulate long enough to reach the target and extravasate there. A challenge is that the particles end up engaging with serum proteins and undergo immune cell recognition and premature clearance. The serum protein binding, also known as protein corona formation, is difficult to prevent, even with artificial protection via "stealth" coating. Protein corona may be problematic as it can interfere with the interaction of targeting ligands with tissue-specific receptors and abrogate the so-called active targeting process, hence, the efficiency of drug delivery. However, recent studies show that serum protein binding to circulating nanoparticles may be actively exploited to enhance their downstream delivery. This review summarizes known issues of protein corona and traditional strategies to control the corona, such as avoiding or overriding its formation, as well as emerging efforts to enhance drug delivery to target organs via nanoparticles. It concludes with a discussion of prevailing challenges in exploiting protein corona for nanoparticle development.

Intravenous Hemostats: Foundation, Targeting, and Controlled-Release

Uncontrollable blood loss is the greatest cause of mortality in prehospital patients and the main source of disability and death in hospital care. Compared with external hemostats, intravenous hemostats are more appropriate for preventing and treating uncontrolled bleeding in vivo and large bleeding on the body surface. This Review initially establishes intravenous hemostats' response basis, including the coagulation mechanism, fibrinolytic pathway, and protein corona. Second, the study of advancement of intravenous hemostat targeting was expanded from two perspectives, cellular hemostatic agents and synthetic hemostatic agents. Meanwhile, after discussing the progress of controlled-release intravenous hemostats with platelets as the stimuli, this Review offers insight into the possibility of controlled-release intravenous hemostats with microenvironment as the stimuli, combining the studies of controlled-release targeted thrombolysis.

Superhydrophobic Biological Fluid-Repellent Surfaces: Mechanisms and Applications

Superhydrophobic biological fluid-repellent surfaces (SBFRSs) have attracted great attention in the treatment of blood and urine-related diseases because of their unique wettability and compatibility, which creates a new path for the development of medical apparatus and instruments, and are expected to create advances in various fields. Here, this review provides an up-to-date summary of research progress on the repellent mechanism and application of SBFRSs. The underlying physical and chemical principles for designing superhydrophobic surfaces are first introduced. Then, the dialectical influences of solid-liquid interactions between superhydrophobic surfaces and biological fluids on the wettability and compatibility are emphatically expounded. Subsequently, attention is drawn to the recent applications of SBFRSs in biomedical fields, such as surgical medical apparatus, implant materials, extracorporeal circulation devices, and biological fluid detection. Finally, the outlook and challenges in terms of employing SBFRSs are also discussed. This review is expected to provide a comprehensive guidance for the preparation of SBFRSs with compatibility and long-term superhydrophobic stability that is closely related to clinical applications.

Biological Features of Nanoparticles: Protein Corona Formation and Interaction with the Immune System

Nanoparticles (NPs) are versatile candidates for nanomedical applications due to their unique physicochemical properties. However, their clinical applicability is hindered by their undesirable recognition by the immune system and the consequent immunotoxicity, as well as their rapid clearance in vivo. After injection, NPs are usually covered with layers of proteins, called protein coronas (PCs), which alter their identity, biodistribution, half-life, and efficacy. Therefore, the characterization of the PC is for in predicting the fate of NPs in vivo. The aim of this review was to summarize the state of the art regarding the intrinsic factors closely related to the NP structure, and extrinsic factors that govern PC formation in vitro. In addition, well-known opsonins, including complement, immunoglobulins, fibrinogen, and dysopsonins, such as histidine-rich glycoprotein, apolipoproteins, and albumin, are described in relation to their role in NP detection by immune cells. Particular emphasis is placed on their role in mediating the interaction of NPs with innate and adaptive immune cells. Finally, strategies to reduce PC formation are discussed in detail.

Synthesis of Surface-Functionalized Molybdenum Disulfide Nanomaterials for Efficient Adsorption and Deep Profiling of the Human Plasma Proteome by Data-Independent Acquisition

Blood is one of the most important clinical samples for protein biomarker discovery, as it provides rich physiological and pathological information and is easy to obtain with low invasiveness. However, the discovery of protein biomarkers in the blood by mass spectrometry (MS)-based proteomic strategies has been shown to be highly challenging due to the particularly large concentration range of proteins and the strong interference by the high-abundant proteins in the blood. Therefore, developing sensitive methods for low-abundant biomarker protein identification is a key issue that has received great attention. Here, we report the synthesis and characterization of surface-functionalized magnetic molybdenum disulfide (MoS₂) for the large-scale adsorption of low-abundant plasma proteins and deep profiling by MS. MoS₂ nanomaterials resulted in the coverage of more than 3400 proteins (including a single-peptide hit) in a single LC-MS analysis without peptide prefractionation using pooled plasma samples, which were five times more than those obtained by the direct analysis of the plasma proteome. A detection limit in the low ng L^-1 range was obtained, which is rare compared with previous reports.

Surface charge influences protein corona, cell uptake and biological effects of carbon dots

Carbon dots are emerging nanoparticles (NPs) with tremendous applications, especially in the biomedical field. Herein is reported the first quantitative proteomic analysis of the protein corona formed on CDs with different surface charge properties. Four CDs were synthesized from citric acid and various amine group-containing passivation reagents, resulting in cationic NPs with increasing zeta (ζ)-potential and density of positive charges. After CD contact with serum, we show that protein corona identity is influenced by CD surface charge properties, which in turn impacts CD uptake and viability loss in macrophages. In particular, CDs with high ζ-potential (>+30 mV) and charge density (>2 μmol mg^-1) are the most highly internalized, and their cell uptake is strongly correlated with a corona enriched in vitronectin, fibulin, fetuin, adiponectin and alpha-glycoprotein. On the contrary, CDs with a lower ζ-potential (+11 mV) and charge density (0.01 μmol mg^-1) are poorly internalized, while having a corona with a very different protein signature characterized by a high abundance of apolipoproteins (APOA1, APOB and APOC), albumin and hemoglobin. These data illustrate how corona characterization may contribute to a better understanding of CD cellular fate and biological effects, and provide useful information for the development of CDs for biomedical applications.

The Yin and Yang of the protein corona on the delivery journey of nanoparticles

Nanoparticles-based drug delivery systems have attracted significant attention in biomedical fields because they can deliver loaded cargoes to the target site in a controlled manner. However, tremendous challenges must still be overcome to reach the expected targeting and therapeutic efficacy in vivo. These challenges mainly arise because the interaction between nanoparticles and biological systems is complex and dynamic and is influenced by the physicochemical properties of the nanoparticles and the heterogeneity of biological systems. Importantly, once the nanoparticles are injected into the blood, a protein corona will inevitably form on the surface. The protein corona creates a new biological identity which plays a vital role in mediating the bio-nano interaction and determining the ultimate results. Thus, it is essential to understand how the protein corona affects the delivery journey of nanoparticles in vivo and what we can do to exploit the protein corona for better delivery efficiency. In this review, we first summarize the fundamental impact of the protein corona on the delivery journey of nanoparticles. Next, we emphasize the strategies that have been developed for tailoring and exploiting the protein corona to improve the transportation behavior of nanoparticles in vivo. Finally, we highlight what we need to do as a next step towards better understanding and exploitation of the protein corona. We hope these insights into the "Yin and Yang" effect of the protein corona will have profound implications for understanding the role of the protein corona in a wide range of nanoparticles.

Nanobiotherapeutic strategies to target immune microenvironment of triple-negative breast cancer

Triple-negative breast cancer (TNBC) is the subtype with the least favourable outcomes in breast cancer. Besides chemotherapy, there is a chronic lack of other effective treatments. Advances in omic technologies have liberated us from the ambiguity of TNBC heterogeneity in terms of cancer cell and immune microenvironment in recent years. This new understanding of TNBC pathology has already led to the exploitation of novel nanoparticulate systems, including tumor vaccines, oncolytic viruses, and antibody derivatives. The revolutionary ideas in the therapeutic landscape provide new opportunities for TNBC patients. Translating these experimental medicines into clinical benefit is both appreciated and challenging. In this review, we describe the prospective nanobiotherapy of TNBC that has been developed to overcome clinical obstacles, and provide our vision for this booming field at the overlap of cancer biotherapy and nanomaterial design.

Harnessing Protein Corona for Biomimetic Nanomedicine Design

Nanoparticles (NPs) are usually treated as multifunctional agents combining several therapeutical applications, like imaging and targeting delivery. However, clinical translation is still largely hindered by several factors, and the rapidly formed protein corona on the surface of NPs is one of them. The formation of protein corona is complicated and irreversible in the biological environment, and protein corona will redefine the “biological identity” of NPs, which will alter the following biological events and therapeutic efficacy. Current understanding of protein corona is still limited and incomplete, and in many cases, protein corona has adverse impacts on nanomedicine, for instance, losing targeting ability, activating the immune response, and rapid clearance. Due to the considerable role of protein corona in NPs’ biological fate, harnessing protein corona to achieve some therapeutic effects through various methods like biomimetic approaches is now treated as a promising way to meet the current challenges in nanomedicine such as poor pharmacokinetic properties, off-target effect, and immunogenicity. This review will first introduce the current understanding of protein corona and summarize the investigation process and technologies. Second, the strategies of harnessing protein corona with biomimetic approaches for nanomedicine design are reviewed. Finally, we discuss the challenges and future outlooks of biomimetic approaches to tune protein corona in nanomedicine.

A mechanical-thermodynamic model for understanding endocytosis of COVID-19 virus SARS-CoV-2

We analyze the endocytosis process of COVID-19 (coronavirus disease 2019) virus SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) using a mechanical-thermodynamic model. The virus particle is designed to interface with the cell membrane as a hard sphere. The role of cytoplasmic BAR (Bin/Amphiphysin/RVs) proteins is considered in the endocytosis. Interestingly, the Endophilin N-BAR cytoplasmic proteins show resistance in participating endocytosis, whereas F-BAR, Arfaptin BAR, Amphiphysin N-BAR, and PX-BAR proteins participate in endocytosis. The increase in membrane tension, concentrated force between the cell membrane receptor, and spike glycoprotein present on the surface of virus particle promote the endocytosis. Also, the increase in the bending modulus of membrane leads to the two-phase solution of BAR protein concentration on the interior of cell membrane surface. We observe an unstable region of protein concentration, which may help one to retard the endocytosis process and thus the viral infection. Though the present study is focused on SARS-CoV-2, it can be extended to understand any other viral infections, involving endocytosis process.

Navigations of the targeting pathway of nanomedicines towards tumor

INTRODUCTION

Nanomedicines (NMs) have emerged as a promising approach for revolutionizing cancer treatment outcomes, mainly due to their benefits in the tumor targeted delivery of therapeutics. The preferential accumulation of NMs in tumor has been widely verified by macroscopical technologies. Accordingly, several classic and emerging targeting mechanisms have been proposed to support the tumor-specific delivery of NMs. The targeting mechanism has been a topic of intensive interest and controversy in the field of NMs development. Especially, the mechanisms by which NMs target tumor remain elusive.

AREA COVERED

This topical review mainly discussed the evolution of the targeting mechanisms, crucial issues associated with each mechanism, and confused debates among the mechanisms. The targeting mechanisms of tumor-specific NMs discussed here include the enhanced permeability and retention (EPR) effect, protein corona-mediated targeting delivery, circulating cell mediated transportation, and transcytosis.

EXPERT OPINION

It is of great significance for ultimate clinical translation to have more comprehensive considerations on the mechanism driving the pathway of NMs toward tumors. Our thoughts in this review are expected to provide comprehensive understanding on the mechanisms and elicit thorough explorations on new mechanism to renovate the knowledge framework of NMs delivery.

Two different protein corona formation modes on Soluplus® nanomicelles

Soluplus® nanomicelles have been widely reported in biomedical field for their excellent drug loading capacity and solubility enhancement ability. However, when administrated in vivo, the protein corona will be formed on Soluplus® nanomicelles, significantly affecting their drug delivery performance. Up to now, few studies examined the protein corona formation process and its impact factors of Soluplus® nanomicelles. The multiple proteins in biofluids may form protein corona in different modes due to their diversified properties. In this study, Bovine serum albumin (BSA), Lysozyme (Lyso) and Bovine hemoglobin (BHb) were chosen as model proteins to investigate the protein corona formation process of Soluplus® nanomicelles. By analyzing the polarity of the protein amino acid residues distributing microenvironments, the results showed that there were two different protein corona formation modes, i.e., surface adsorption and insertion, which were determined by the hydrophilicity of proteins. The hydrophobic BHb followed the insertion mode while hydrophilic BSA and Lyso followed the surface adsorption mode. Ultimately, upon protein corona formation, the size and surface chemistry of nanomicelles was significantly affected. We believe this study will provide a new research paradigm to the design and application of Soluplus® nanomicelles.