Unveiling the in Vivo Protein Corona of Circulating Leukocyte-like Carriers

Preadsorbed Chymotrypsin Modulated the Composition of Protein Corona and Immunological Response

It is well-known that proteins after administration into biological environments adsorb on the surface of nanoparticles (NPs). The biological identity could be determined by protein corona, but whether and how the preadsorbed molecules impact the composition of the corona and immunological response have rarely been reported. Here, the effects of preadsorbed chymotrypsin (Chy) on forming protein corona and subsequent immunological response are reported. We find that preadsorbed Chy on the surface of AuNPs results in a protein corona with enriched immunoglobulins and reduced human serum albumin protein, which further affect the polarization of macrophages into specific phenotypes. Our study suggests that the protein surrounding the nanoparticles could affect the protein corona and immunological response, which may direct the preparation of multifunctional nanomedicine for future studies.

Protein Corona Sensor Array Nanosystem for Detection of Coronary Artery Disease

Coronary artery disease (CAD) is the most common type of heart disease and represents the leading cause of death in both men and women worldwide. Early detection of CAD is crucial for decreasing mortality, prolonging survival, and improving patient quality of life. Herein, a non-invasive is described, nanoparticle-based diagnostic technology which takes advantages of proteomic changes in the nano-bio interface for CAD detection. Nanoparticles (NPs) exposed to biological fluids adsorb on their surface a layer of proteins, the "protein corona" (PC). Pathological changes that alter the plasma proteome can directly result in changes in the PC. By forming disease-specific PCs on six NPs with varying physicochemical properties, a PC-based sensor array is developed for detection of CAD using specific PC pattern recognition. While the PC of a single NP may not provide the required specificity, it is reasoned that multivariate PCs across NPs with different surface chemistries, can provide the desirable information to selectively discriminate the condition under investigation. The results suggest that such an approach can detect CAD with an accuracy of 92.84%, a sensitivity of 87.5%, and a specificity of 82.5%. These new findings demonstrate the potential of PC-based sensor array detection systems for clinical use.

Unravelling the role of lipid composition on liposome-protein interactions

Upon in vivo administration of nanoparticles, a protein corona forms on their surface and affects their half-life in circulation, biodistribution properties, and stability; in turn, the composition of the protein corona depends on the physico-chemical properties of the nanoparticles. We have previously observed lipid composition-dependent in vitro and in vivo microRNA delivery from lipid nanoparticles. Here, we carried out an extensive physico-chemical characterisation to understand the role of the lipid composition on the in vivo fate of lipid-based nanoparticles. We used a combination of differential scanning calorimetry (DSC), membrane deformability measurements, isothermal titration calorimetry (ITC), and dynamic light scattering (DLS) to probe the interactions between the nanoparticle surface and bovine serum albumin (BSA) as a model protein. The lipid composition influenced membrane deformability, improved lipid intermixing, and affected the formation of lipid domains while BSA binding to the liposome surface was affected by the PEGylated lipid content and the presence of cholesterol. These findings highlight the importance of the lipid composition on the protein-liposome interaction and provide important insights for the design of lipid-based nanoparticles for drug delivery applications.

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

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

Glutamate affects self-assembly, protein corona, and anti-4 T1 tumor effects of melittin/vitamin E-succinic acid-(glutamate)n nanoparticles

Melittin (M) has attracted increasing attention for its significant antitumor effects and various immunomodulatory effects. However, various obstacles such as the short plasma half-life and adverse reactions restrict its application. This study aimed to systematically investigate the self-assembly mechanism, components of the protein corona, targeting behavior, and anti-4 T1 tumor effect of vitamin E-succinic acid-(glutamate)n /melittin nanoparticles with varying amounts of glutamic acid. Here, we present a new vitamin E-succinic acid-(glutamate)5 (E5), vitamin E-succinic acid-(glutamate)10 (E10) or vitamin E-succinic acid-(glutamate)15 (E15), and their co-assembly system with positively charged melittin in water. The molecular dynamics simulations demonstrated that the electrostatic energy and van der Waals force in the system decreased significantly with the increase in the amount of glutamic acid. The melittin and E15 system exhibited the optimal stability for nanoparticle self-assembly. When nanoparticles derived from different self-assembly systems were co-incubated with plasma from patients with breast cancer, the protein corona showed heterogeneity. In vivo imaging demonstrated that an increase in the number of glutamic acid residues enhanced circulation duration and tumor-targeting effects. Both in vitro and in vivo antitumor evaluation indicated a significant increase in the antitumor effect with the addition of glutamic acid. According to our research findings, the number of glutamic acid residues plays a crucial role in the targeted delivery of melittin for immunomodulation and inhibition of 4 T1 breast cancer. Due to the self-assembly capabilities of vitamin E-succinic acid-(glutamate)n in water, these nanoparticles carry significant potential for delivering cationic peptides such as melittin.

Targeted Therapy of Acute Liver Injury via Cryptotanshinone-Loaded Biomimetic Nanoparticles Derived from Mesenchymal Stromal Cells Driven by Homing

Acute liver injury (ALI) has the potential to compromise hepatic function rapidly, with severe cases posing a considerable threat to human health and wellbeing. Conventional treatments, such as the oral administration of antioxidants, can inadvertently lead to liver toxicity and other unwanted side effects. Mesenchymal stromal cells (MSCs) can target therapeutic agents directly to inflammatory sites owing to their homing effect, and they offer a promising avenue for the treatment of ALI. However, the efficacy and feasibility of these live cell products are hampered by challenges associated with delivery pathways and safety concerns. Therefore, in this work, MSC membranes were ingeniously harnessed as protective shells to encapsulate synthesized PLGA nanoparticle cores (PLGA/MSCs). This strategic approach enabled nanoparticles to simulate endogenous substances and yielded a core-shell nano-biomimetic structure. The biomimetic nanocarrier remarkably maintained the homing ability of MSCs to inflammatory sites. In this study, cryptotanshinone (CPT)-loaded PLGA/MSCs (CPT@PLGA/MSC) were prepared. These nanoparticles can be effectively internalized by LO2 cells. They reduced cellular oxidative stress and elevated inflammatory levels. In vivo results suggested that, after intravenous administration, CPT@PLGA/MSCs significantly reduced uptake by the reticuloendothelial system and immune recognition compared to PLGA nanoparticles without MSC membrane coatings, subsequently resulting in their targeted and enhanced accumulation in the liver. The effectiveness of CPT@PLGA/MSCs in alleviating carbon tetrachloride-induced oxidative stress and inflammation in a mouse model was unequivocally demonstrated through comprehensive histological examination and liver function tests. This study introduces a pioneering strategy with substantial potential for ALI treatment.

Multifunctional cell membranes-based nano-carriers for targeted therapies: a review of recent trends and future perspective

Nanotechnology has ignited a transformative revolution in disease detection, prevention, management, and treatment. Central to this paradigm shift is the innovative realm of cell membrane-based nanocarriers, a burgeoning class of biomimetic nanoparticles (NPs) that redefine the boundaries of biomedical applications. These remarkable nanocarriers, designed through a top-down approach, harness the intrinsic properties of cell-derived materials as their fundamental building blocks. Through shrouding themselves in natural cell membranes, these nanocarriers extend their circulation longevity and empower themselves to intricately navigate and modulate the multifaceted microenvironments associated with various diseases. This comprehensive review provides a panoramic view of recent breakthroughs in biomimetic nanomaterials, emphasizing their diverse applications in cancer treatment, cardiovascular therapy, viral infections, COVID-19 management, and autoimmune diseases. In this exposition, we deliver a concise yet illuminating overview of the distinctive properties underpinning biomimetic nanomaterials, elucidating their pivotal role in biomedical innovation. We subsequently delve into the exceptional advantages these nanomaterials offer, shedding light on the unique attributes that position them at the forefront of cutting-edge research. Moreover, we briefly explore the intricate synthesis processes employed in creating these biomimetic nanocarriers, shedding light on the methodologies that drive their development.

Variations in metabolite profiles of serum coronas produced around PEGylated liposomal drugs by surface property

Understanding biomolecular coronas that spontaneously occur around nanocarriers (NCs) in biological fluids is critical to nanomedicine as the coronas influence the behaviors of NCs in biological systems. In contrast to extensive investigations of protein coronas over the past decades, understanding of the coronas of biomolecules beyond proteins, e.g., metabolites, has been rather limited despite such biochemicals being ubiquitously involved in the coronas, which may influence the bio-nano interactions and thus exert certain biological impacts. In this study, serum biomolecular coronas, in particular the coronas of metabolites including lipids, around PEGylated doxorubicin-loaded liposomes with different surface property were investigated. The surface properties of liposomal drugs varied in terms of surface charge and PEGylation density by employing different ionic lipids such as DOTAP and DOPS and different concentrations of PEGylation lipids in liposome formulation. Using the liposomal drugs, the influence of the surface property on the serum metabolite profiles in the coronas was traced for target molecules of 220 lipids and 88 hydrophilic metabolites. From the results, it was found that metabolites rather than proteins mainly constitute the serum coronas on the liposomal drugs. Most of the serum metabolites were found to be retained in the coronas but with altered abundances. Depending on their class, lipids exhibited a different dependence on the surface property. However, overall, lipids appeared to favor corona formation on more negatively charged and PEGylated surfaces. Hydrophilic metabolites also exhibited a similar propensity for corona formation. This study on the surface dependence of metabolite corona formation provides a fundamental contribution toward attaining a comprehensive understanding of biomolecular coronas, which will be critical to the development of efficient nanomedicine.

Physicochemical Properties and Route of Systemic Delivery Control the In Vivo Dynamics and Breakdown of Radiolabeled Gold Nanostars

The in vivo dynamics of nanoparticles requires a mechanistic understanding of multiple factors. Here, for the first time, the surprising breakdown of functionalized gold nanostars (F-AuNSs) conjugated with antibodies and 64 Cu radiolabels in vivo and in artificial lysosomal fluid ex vivo, is shown. The short-term biodistribution of F-AuNSs is driven by the route of systemic delivery (intravenous vs intraperitoneal) and long-term fate is controlled by the tissue type in vivo. In vitro studies including endocytosis pathways, intracellular trafficking, and opsonization, are combined with in vivo studies integrating a milieu of spectroscopy and microcopy techniques that show F-AuNSs dynamics is driven by their physicochemical properties and route of delivery. F-AuNSs break down into sub-20 nm broken nanoparticles as early as 7 days postinjection. Martini coarse-grained simulations are performed to support the in vivo findings. Simulations suggest that shape, size, and charge of the broken nanoparticles, and composition of the lipid membrane depicting various tissues govern the interaction of the nanoparticles with the membrane, and the rate of translocation across the membrane to ultimately enable tissue clearance. The fundamental study addresses critical gaps in the knowledge regarding the fate of nanoparticles in vivo that remain a bottleneck in their clinical translation.

Immunomodulatory biomimetic nanoparticles target articular cartilage trauma after systemic administration

Post-traumatic osteoarthritis (PTOA) is one of the leading causes of disability in developed countries and accounts for 12% of all osteoarthritis cases in the United States. After trauma, inflammatory cells (macrophages amongst others) are quickly recruited within the inflamed synovium and infiltrate the joint space, initiating dysregulation of cartilage tissue homeostasis. Current therapeutic strategies are ineffective, and PTOA remains an open clinical challenge. Here, the targeting potential of liposome-based nanoparticles (NPs) is evaluated in a PTOA mouse model, during the acute phase of inflammation, in both sexes. NPs are composed of biomimetic phospholipids or functionalized with macrophage membrane proteins. Intravenous administration of NPs in the acute phase of PTOA and advanced in vivo imaging techniques reveal preferential accumulation of NPs within the injured joint for up to 7 days post injury, in comparison to controls. Finally, imaging mass cytometry uncovers an extraordinary immunomodulatory effect of NPs that are capable of decreasing the amount of immune cells infiltrating the joint and conditioning their phenotype. Thus, biomimetic NPs could be a powerful theranostic tool for PTOA as their accumulation in injury sites allows their identification and they have an intrinsic immunomodulatory effect.

Uncovering the Fate and Risks of Intravenously Injected Prussian Blue Nanoparticles in mice by an Integrated Methodology of Toxicology, Pharmacokinetics, Proteomics, and Metabolomics

BACKGROUND

Prussian blue (PB) nanoparticles (NPs) have been intensively investigated for medical applications, but an in-depth toxicological investigation of PB NPs has not been implemented. In the present study, a comprehensive investigation of the fate and risks of PB NPs after intravenous administration was carried out by using a mouse model and an integrated methodology of pharmacokinetics, toxicology, proteomics, and metabolomics.

RESULTS

General toxicological studies demonstrated that intravenous administration of PB NPs at 5 or 10 mg/kg could not induce obvious toxicity in mice, while mice treated with a relatively high dose of PB NPs at 20 mg/kg exhibited loss of appetite and weight decrease in the first two days postinjection. Pharmacokinetic studies revealed that intravenously administered PB NPs (20 mg/kg) underwent fast clearance from blood, highly accumulated in the liver and lungs of mice, and finally cleared from tissues. By further integrated proteomics and metabolomics analysis, we found that protein expression and metabolite levels changed significantly in the liver and lungs of mice due to the high accumulation of PB NPs, leading to slight inflammatory responses and intracellular oxidative stress.

CONCLUSIONS

Collectively, our integrated experimental data imply that the high accumulation of PB NPs may cause potential risks to the liver and lungs of mice, which will provide detailed references and guidance for further clinical application of PB NPs in the future.

Metal and Metal Oxides Nanoparticles and Nanosystems in Anticancer and Antiviral Theragnostic Agents

The development of antiviral treatment and anticancer theragnostic agents in recent decades has been associated with nanotechnologies, and primarily with inorganic nanoparticles (INPs) of metal and metal oxides. The large specific surface area and its high activity make it easy to functionalize INPs with various coatings (to increase their stability and reduce toxicity), specific agents (allowing retention of INPs in the affected organ or tissue), and drug molecules (for antitumor and antiviral therapy). The ability of magnetic nanoparticles (MNPs) of iron oxides and ferrites to enhance proton relaxation in specific tissues and serve as magnetic resonance imaging contrast agents is one of the most promising applications of nanomedicine. Activation of MNPs during hyperthermia by an external alternating magnetic field is a promising method for targeted cancer therapy. As therapeutic tools, INPs are promising carriers for targeted delivery of pharmaceuticals (either anticancer or antiviral) via magnetic drug targeting (in case of MNPs), passive or active (by attaching high affinity ligands) targeting. The plasmonic properties of Au nanoparticles (NPs) and their application for plasmonic photothermal and photodynamic therapies have been extensively explored recently in tumor treatment. The Ag NPs alone and in combination with antiviral medicines reveal new possibilities in antiviral therapy. The prospects and possibilities of INPs in relation to magnetic hyperthermia, plasmonic photothermal and photodynamic therapies, magnetic resonance imaging, targeted delivery in the framework of antitumor theragnostic and antiviral therapy are presented in this review.

A Bird’s Eye View of Various Cell-Based Biomimetic Nanomedicines for the Treatment of Arthritis

Arthritis is the inflammation and tenderness of the joints because of some metabolic, infectious, or constitutional reasons. Existing arthritis treatments help in controlling the arthritic flares, but more advancement is required to cure arthritis meticulously. Biomimetic nanomedicine represents an exceptional biocompatible treatment to cure arthritis by minimizing the toxic effect and eliminating the boundaries of current therapeutics. Various intracellular and extracellular pathways can be targeted by mimicking the surface, shape, or movement of the biological system to form a bioinspired or biomimetic drug delivery system. Different cell-membrane-coated biomimetic systems, and extracellular-vesicle-based and platelets-based biomimetic systems represent an emerging and efficient class of therapeutics to treat arthritis. The cell membrane from various cells such as RBC, platelets, macrophage cells, and NK cells is isolated and utilized to mimic the biological environment. Extracellular vesicles isolated from arthritis patients can be used as diagnostic tools, and plasma or MSCs-derived extracellular vesicles can be used as a therapeutic target for arthritis. Biomimetic systems guide the nanomedicines to the targeted site by hiding them from the surveillance of the immune system. Nanomedicines can be functionalized using targeted ligand and stimuli-responsive systems to reinforce their efficacy and minimize off-target effects. This review expounds on various biomimetic systems and their functionalization for the therapeutic targets of arthritis treatment, and discusses the challenges for the clinical translation of the biomimetic system.

Current progress of mesenchymal stem cell membrane-camouflaged nanoparticles for targeted therapy

Nanodrug delivery systems have been widely used in disease treatment. However, weak drug targeting, easy to be cleared by the immune system, and low biocompatibility are great obstacles for drug delivery. As an important part of cell information transmission and behavior regulation, cell membrane can be used as drug coating material which represents a promising strategy and can overcome these limitations. Mesenchymal stem cell (MSC) membrane, as a new carrier, has the characteristics of active targeting and immune escape of MSC, and has broad application potential in tumor treatment, inflammatory disease, tissue regeneration and other fields. Here, we review recent progress on the use of MSC membrane-coated nanoparticles for therapy and drug delivery, aiming to provide guidance for the design and clinical application of membrane carrier in the future.

Implications of biomimetic nanocarriers in targeted drug delivery

Nanomaterials and nanostructures have shown fascinating performances in various biomedicine fields, from cosmetic to cancer diagnosis and therapy. Engineered nanomaterials can encapsulate both lipophilic and hydrophilic substances/drugs to eliminate their limitations in the free forms, such as low bioavailability, multiple drug administration, off-target effects, and various side effects. Moreover, it is possible to deliver the loaded cargo to the desired site of action using engineered nanomaterials. One approach that has made nanocarriers more sophisticated is the "biomimetic" concept. In this scenario, biomolecules (e.g., natural proteins, peptides, phospholipids, cell membranes) are used as building blocks to construct nanocarriers and/or modify agents. For instance, it has been reported that specific cells tend to migrate to a particular site during specific circumstances (e.g., inflammation, tumor formation). Employing the cell membrane of these cells as a coating for nanocarriers confers practical targeting approaches. Accordingly, we introduce the biomimetic concept in the current study, review the recent studies, challenge the issues, and provide practical solutions.

Passive, active and endogenous organ-targeted lipid and polymer nanoparticles for delivery of genetic drugs

Genetic drugs based on nucleic acid biomolecules are a rapidly emerging class of medicines that directly reprogramme the central dogma of biology to prevent and treat disease. However, multiple biological barriers normally impede the intracellular delivery of nucleic acids, necessitating the use of a delivery system. Lipid and polymer nanoparticles represent leading approaches for the clinical translation of genetic drugs. These systems circumnavigate biological barriers and facilitate the intracellular delivery of nucleic acids in the correct cells of the target organ using passive, active and endogenous targeting mechanisms. In this Review, we highlight the constituent materials of these advanced nanoparticles, their nucleic acid cargoes and how they journey through the body. We discuss targeting principles for liver delivery, as it is the organ most successfully targeted by intravenously administered nanoparticles to date, followed by the expansion of these concepts to extrahepatic (non-liver) delivery. Ultimately, this Review connects emerging materials and biological insights playing key roles in targeting specific organs and cells in vivo.

Tyrosine kinase inhibitor-loaded biomimetic nanoparticles as a treatment for osteosarcoma

Small-molecule tyrosine kinase inhibitors (TKIs) represent a potentially powerful approach to the treatment of osteosarcoma (OS). However, dose-limiting toxicity, therapeutic efficacy, and targeting specificity are significant barriers to the use of TKIs in the clinic. Notably among TKIs, ponatinib demonstrated potent anti-tumor activity; however, it received an FDA black box warning for potential side effects. We propose ponatinib-loaded biomimetic nanoparticles (NPs) to repurpose ponatinib as an efficient therapeutic option for OS. In this study, we demonstrate enhanced targeting ability and maintain potent ponatinib nano-therapeutic activity, while also reducing toxicity. In in vitro two- and three-dimensional models, we demonstrate that ponatinib-loaded biomimetic NPs maintain the efficacy of the free drug, while in vivo we show that they can improve tumor targeting, slow tumor growth, and reduce evidence of systemic toxicities. Though there is limited Pon encapsulation within NPs, this platform may improve current therapeutic approaches and reduce dosage-related side effects to achieve better clinical outcomes in OS patients.

Graphical Abstract

A Macrophage Membrane-Polymer Hybrid Biomimetic Nanoplatform for Therapeutic Delivery of Somatostatin Peptide to Chronic Pancreatitis

The clinical translation of therapeutic peptides is generally challenged by multiple issues involving absorption, distribution, metabolism and excretion. In this study, a macrophage membrane-coated poly(lactic-co-glycolic acid) (PLGA) nanodelivery system was developed to enhance the bioavailability of the somatostatin (SST) peptide, which faces the hurdles of short half-life and potential side effects in the treatment of chronic pancreatitis. Using a facile nanoprecipitation strategy, SST was loaded in the nanoparticles with an encapsulation efficiency (EE) and a loading efficiency (LE) of 73.68 ± 3.56% and 1.47 ± 0.07%, respectively. The final formulation of SST-loaded nanoparticles with the camouflage of macrophage membrane (MP-SST) showed a mean diameter of 151 ± 4 nm and an average zeta potential of −29.6 ± 0.3 mV, which were stable long term during storage. With an above 90% cell viability, a hemolysis level of about 2% (<5%) and a preference for being ingested by activated endothelial cells compared to macrophages, the membrane−polymer hybrid nanoparticle showed biocompatibility and targeting capability in vitro. After being intravenously administered to mice with chronic pancreatitis, the MP-SST increased the content of SST in the serum (123.6 ± 13.6 pg/mL) and pancreas (1144.9 ± 206.2 pg/g) compared to the treatment of (Dulbecco’s phosphate-buffered saline) DPBS (61.7 ± 6.0 pg/mL in serum and 740.2 ± 172.4 pg/g in the pancreas). The recovery of SST by MP-SST downregulated the expressions of chronic pancreatitis-related factors and alleviated the histologic severity of the pancreas to the greatest extent compared to other treatment groups. This augmentation of SST therapeutic effects demonstrated the superiority of integrating the synthetic polymer with biological membranes in the design of nanoplatforms for advanced and smart peptide delivery. Other peptides like SST can also be delivered via the membrane−polymer hybrid nanosystem for the treatment of diseases, broadening and promoting the potential clinical applications of peptides as therapeutics.

Systematic design of cell membrane coating to improve tumor targeting of nanoparticles

Cell membrane (CM) coating technology is increasingly being applied in nanomedicine, but the entire coating procedure including adsorption, rupture, and fusion is not completely understood. Previously, we showed that the majority of biomimetic nanoparticles (NPs) were only partially coated, but the mechanism underlying this partial coating remains unclear, which hinders the further improvement of the coating technique. Here, we show that partial coating is an intermediate state due to the adsorption of CM fragments or CM vesicles, the latter of which could eventually be ruptured under external force. Such partial coating is difficult to self-repair to achieve full coating due to the limited membrane fluidity. Building on our understanding of the detailed coating process, we develop a general approach for fixing the partial CM coating: external phospholipid is introduced as a helper to increase CM fluidity, promoting the final fusion of lipid patches. The NPs coated with this approach have a high ratio of full coating (~23%) and exhibit enhanced tumor targeting ability in comparison to the NPs coated traditionally (full coating ratio of ~6%). Our results provide a mechanistic basis for fixing partial CM coating towards enhancing tumor accumulation.

The amount of dextran in PLGA nanocarriers modulates protein corona and promotes cell membrane damage

Polymeric nanocarriers (NCs) are efficient vehicles to prevent drug unspecific biodistribution and increase the drug amounts delivered to tumor tissues. However, some toxicological aspects of NCs still lack a comprehensive assessment, such as their effects on cellular processes that lead to toxicity. We evaluate the interaction of poly(lactic-co-glycolic acid) (PLGA) NCs prepared using dextran (Dex) and Pluronic®-F127 as stabilizing agents with myocardial cells (H9C2), breast adenocarcinoma cells (MCF-7) and macrophages (RAW 264.7) to address the effect of Dex in PLGA NC formulations. By an emulsion diffusion method, doxorubicin-loaded NCs were prepared with no Dex (PLGA-DOX), 1% (w/v) Dex (Dex1/PLGA-DOX) and 5% (w/v) Dex (Dex5/PLGA-DOX). Uptake analyses revealed a significant reduction in Dex5/PLGA-DOX NC uptake by H9C2 and MCF-7, as in the case of Dex1/PLGA-DOX NCs in the absence of in vitro protein corona, revealing an effect of dextran concentration on the formation of protein corona. RAW 264.7 cells presented a greater uptake of Dex5/PLGA-DOX NCs than the other NCs likely because of receptor mediated endocytosis, since C-type lectins like SIGN-R1, mannose receptors and scavenger receptor type 1 that are expressed in RAW 264.7 can mediate Dex uptake. Despite the lower uptake, Dex5/PLGA-DOX NCs promote the generation of reactive oxygen species and oxidative membrane damage in MCF-7 and H9C2 even though cellular metabolic activity assessed by MTT was comparable among all the NCs. Our results highlight the importance of an in-depth investigation of the NC-cell interaction considering additional mechanisms of damage apart from metabolic variations, as nanoparticle-induced damage is not limited to imbalance in metabolic processes, but also associated with other mechanisms, e.g., membrane and DNA damage.

Biomimetic Nanovesicles—Sources, Design, Production Methods, and Applications

Despite all the progress in the field of liposomes and nanoparticles for applications as drug and gene delivery systems, the specific targeting and immune system escape capabilities of these systems are still limited. Biomimetic nanovesicles emerged as a strategy to overcome these and other limitations associated with synthetic carriers, such as short circulation time, cytotoxicity, and difficulty in crossing biological barriers, since many of the desirable abilities of drug delivery systems are innate characteristics of biological vesicles. Thus, the question arises: would biomimetic nanovesicles be responsible for addressing these advances? It is currently known that biomimetic nanovesicles (BNV) can combine the intrinsic advantages of natural materials with the well-known production methods and controllability of synthetic systems. Besides, the development of the biotechnology and nanotechnology fields has provided a better understanding of the functionalities of biological vesicles and the means for the design and production of biomimetic nanovesicles (BNV). Based on this, this work will focus on tracking the main research on biomimetic nanovesicles (BNV) applied as drug and gene delivery systems, and for vaccines applications. In addition, it will describe the different sources of natural vesicles, the technical perspectives on obtaining them, and the possibility of their hybridization with synthetic liposomes.

Stem cell membrane-coated abiotic nanomaterials for biomedical applications

Nanoscale materials have been extensively employed for diagnostic and therapeutic purposes. However, the developed nanosystems still suffer from some limitations, namely the rapid elimination by the immune system, lack of targeting to specific cells, and insufficient biocompatibility. Therefore, novel strategies based upon a biomimetic approach have received attention to improving the pharmacokinetics and safety profile of nanosystems. One promising strategy is the application of a biomimetic coating consisting of cell membranes derived from different cell types onto nanoparticle cores. Stem cells have been investigated to develop targeted nanodevices owing to their excellent intrinsic tissue-specific homing features, protecting them from the immune system to reach the sites of inflammation. This targeting ability is conferred by a surface repertoire of stem cell-associated biomolecules. Such nanoscopical materials offer sustained circulation and boosted drug accumulation at target sites, augmenting therapeutic efficacy and safety. Additionally, the coating of nanoparticles with cell membranes acts as a camouflage mechanism to increase their circulation time. The current review explores the particular features of stem cell membrane coating as multifunctional biomimetic surface functionalization agents to camouflage nanoparticle cores. Biomedical applications of engineered stem cell membrane-coated nanoparticles, challenges in clinical translation, and their future prospects are addressed.

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.

Stem Cell Membrane-Encapsulated Zeolitic Imidazolate Framework-8: A Targeted Nano-Platform for Osteogenic Differentiation

Mesenchymal stem cells (MSCs) have been recognized as one of the most promising pharmaceutical multipotent cells, and a key step for their wide application is to safely and efficiently regulate their activities. Various methods have been proposed to regulate the directional differentiation of MSCs during tissue regeneration, such as nanoparticles and metal ions. Herein, nanoscale zeolitic imidazolate framework-8 (ZIF-8), a Zn-based metal-organic framework, is modified to direct MSCs toward an osteoblast lineage. Specifically, ZIF-8 nanoparticles are encapsulated using stem cell membranes (SCMs) to mimic natural molecules and improve the biocompatibility and targeted ability toward MSCs. SCM/ZIF-8 nanoparticles adjust the sustained release of Zn²⁺ , and promote their specific internalization toward MSCs. The internalized SCM/ZIF-8 nanoparticles show excellent biocompatibility, and increase MSCs' osteogenic potentials. Moreover, RNA-sequencing results elucidate that the activated cyclic adenosine 3,5-monophosphate (cAMP)-PKA-CREB signaling pathway can be dominant in accelerating osteogenic differentiation. In vivo, SCM/ZIF-8 nanoparticles greatly promote the formation of new bone tissue in the femoral bone defect detected by 3D micro-CT, hematoxylin and eosin staining, and Masson staining after 4 weeks. Overall, the SCM-derived ZIF-8 nanostructures achieve the superior targeting ability, biocompatibility, and enhanced osteogenesis, providing a constructive design for tissue repair.

The effects of protein corona on in vivo fate of nanocarriers

With the emerging advances in utilizing nanocarriers for biomedical applications, a molecular-level understanding of the in vivo fate of nanocarriers is necessary. After administration into human fluids, nanocarriers can attract proteins onto their surfaces, forming an assembled adsorption layer called protein corona (PC). The formed PC can influence the physicochemical properties and subsequently determine nanocarriers' biological behaviors. Therefore, an in-depth understanding of the features and effects of the PC on the nanocarriers' surface is the first and most important step towards controlling their in vivo fate. This review introduces fundamental knowledge such as the definition, formation, composition, conformation, and characterization of the PC, emphasizing the in vivo environmental factors that control the PC formation. The effect of PC on the physicochemical properties and thus biological behaviors of nanocarriers was then presented and thoroughly discussed. Finally, we proposed the design strategies available for engineering PC onto nanocarriers to manipulate them with the desired surface properties and achieve the best biomedical outcomes.

Protein corona: challenges and opportunities for targeted delivery of nanomedicines

INTRODUCTION

Targeted drug delivery has been widely explored as a promising way to improve the performance of nanomedicines. However, protein corona formed on the nano-surface represents a major issue that has great impacts on the in vivo fate of targeting nanomedicines, which has been overlooked in the past. With the increasing understanding of protein corona in the recent decade, many efforts have been made to improve targeting efficacy.

AREAS COVERED

In this review, we briefly summarize insights of targeted delivery systems inspired by protein corona, and discuss the promising strategies to regulate protein corona for better targeting.

EXPERT OPINION

The interaction between nanomedicines and endogenous proteins brings great uncertainty and challenges, but it also provides great opportunities for the development of targeting nanomedicines at the same time. With increasing understanding of protein corona, the strategies to regulate protein corona pave new avenues for the development of targeting nanomedicines.

Recent Advances in Nano-Therapeutic Strategies for Osteoarthritis

Osteoarthritis (OA) is the most common type of arthritis and the leading cause of disability globally. It tends to occur in middle age or due to an injury or obesity. OA occurs with the onset of symptoms, including joint swelling, joint effusion, and limited movement at a late stage of the disease, which leads to teratogenesis and loss of joint function. During the pathogenesis of this degenerative joint lesion, several local inflammatory responses are activated, resulting in synovial proliferation and pannus formation that facilitates the destruction of the bone and the articular cartilage. The commonly used drugs for the clinical diagnosis and treatment of OA have limitations such as low bioavailability, short half-life, poor targeting, and high systemic toxicity. With the application of nanomaterials and intelligent nanomedicines, novel nanotherapeutic strategies have shown more specific targeting, prolonged half-life, refined bioavailability, and reduced systemic toxicity, compared to the existing medications. In this review, we summarized the recent advancements in new nanotherapeutic strategies for OA and provided suggestions for improving the treatment of OA.

COVID-19 inflammation and implications in drug delivery

Growing evidence indicates that hyperinflammatory syndrome and cytokine storm observed in COVID-19 severe cases are narrowly associated with the disease's poor prognosis. Therefore, targeting the inflammatory pathways seems to be a rational therapeutic strategy against COVID-19. Many anti-inflammatory agents have been proposed; however, most of them suffer from poor bioavailability, instability, short half-life, and undesirable biodistribution resulting in off-target effects. From a pharmaceutical standpoint, the implication of COVID-19 inflammation can be exploited as a therapeutic target and/or a targeting strategy against the pandemic. First, the drug delivery systems can be harnessed to improve the properties of anti-inflammatory agents and deliver them safely and efficiently to their therapeutic targets. Second, the drug carriers can be tailored to develop smart delivery systems able to respond to the microenvironmental stimuli to release the anti-COVID-19 therapeutics in a selective and specific manner. More interestingly, some biosystems can simultaneously repress the hyperinflammation due to their inherent anti-inflammatory potency and endow their drug cargo with a selective delivery to the injured sites.

Protein adsorption onto nanomaterials engineered for theranostic applications

The key role of biomolecule adsorption onto engineered nanomaterials for therapeutic and diagnostic purposes has been well recognized by the nanobiotechnology community, and our mechanistic understanding of nano-bio interactions has greatly advanced over the past decades. Attention has recently shifted to gaining active control of nano-bio interactions, so as to enhance the efficacy of nanomaterials in biomedical applications. In this review, we summarize progress in this field and outline directions for future development. First, we briefly review fundamental knowledge about the intricate interactions between proteins and nanomaterials, as unraveled by a large number of mechanistic studies. Then, we give a systematic overview of the ways that protein-nanomaterial interactions have been exploited in biomedical applications, including the control of protein adsorption for enhancing the targeting efficiency of nanomedicines, the design of specific protein adsorption layers on the surfaces of nanomaterials for use as drug carriers, and the development of novel nanoparticle array-based sensors based on nano-bio interactions. We will focus on particularly relevant and recent examples within these areas. Finally, we conclude this topical review with an outlook on future developments in this fascinating research field.

The Janus of Protein Corona on nanoparticles for tumor targeting, immunotherapy and diagnosis

The therapeutics based on nanoparticles (NPs) are considered as the promising strategy for tumor detection and treatment. However, one of the most challenges is the adsorption of biomolecules on NPs after their exposition to biological medium, leading unpredictable in vivo behaviors. The interactions caused by protein corona (PC) will influence the biological fate of NPs in either negative or positive ways, including (i) blood circulation, accumulation and penetration of NPs at targeting sites, and further cellular uptake in tumor targeting delivery; (ii) interactions between NPs and receptors on immune cells for immunotherapy. Besides, PC on NPs could be utilized as new biomarker in tumor diagnosis by identifying the minor change of protein concentration led by tumor growth and invasion in blood. Herein, the mechanisms of these PC-mediated effects will be introduced. Moreover, the recent advances about the strategies will be reviewed to reduce negative effects caused by PC and/or utilize positive effects of PC on tumor targeting, immunotherapy and diagnosis, aiming to provide a reasonable perspective to recognize PC with their applications.

Bi-Functional Gold Nanorod-Protein Conjugates with Biomimetic BSA@Folic Acid Corona for Improved Tumor Targeting and Intracellular Delivery of Therapeutic Proteins in Colon Cancer 3D Spheroids

Gold nanorods (AuNRs) remain well-developed inorganic nanocarriers of small molecules for a plethora of biomedical and therapeutic applications. However, the delivery of therapeutic proteins using AuNRs with high protein loading capacity (LC), serum stability, excellent target specificity, and minimal off-target protein release is not known. Herein, we report two bi-functional AuNR-protein nanoconjugates, AuNR@EGFP-BSA_FA and AuNR@RNaseA-BSA_FA, supramolecularly coated with folic acid-modified BSA (BSA_FA) acting as biomimetic protein corona to demonstrate targeted cytosolic delivery of enhanced green fluorescent protein (EGFP) and therapeutic ribonuclease A enzyme (RNase A) in their functional forms. AuNR@EGFP-BSA_FA and AuNR@RNaseA-BSA_FA exhibit high LCs of ∼42 and ∼54%, respectively, increased colloidal stability, and rapid protein release in the presence of biological thiols. As a nanocarrier, AuNR@EGFP-BSA_FA and AuNR@RNaseA-BSA_FA show resistance to corona formation in high-serum media even after 24 h, guaranteeing a greater circulation lifetime. Folate receptor-targeting BSA_FA on the AuNR surface facilitates the receptor-mediated internalization, followed by the release of EGFP and RNase A in HT29 cells. The green fluorescence dispersed throughout the cell's cytoplasm indicates successful cytosolic delivery of EGFP by AuNR@EGFP-BSA_FA. AuNR@RNaseA-BSA_FA-mediated therapeutic RNase A delivery in multicellular 3D spheroids of HT29 cells exhibits a radical reduction in the cellular RNA fluorescence intensity to 38%, signifying RNA degradation and subsequent cell death. The versatile nanoformulation strategy in terms of the anisotropic particle morphology, protein type, and ability for targeted delivery in the functional form makes the present AuNR-protein nanoconjugates a promising platform for potential application in cancer management.

Performance of nanoparticles for biomedical applications: The in vitro/in vivo discrepancy

Nanomedicine has a great potential to revolutionize the therapeutic landscape. However, up-to-date results obtained from in vitro experiments predict the in vivo performance of nanoparticles weakly or not at all. There is a need for in vitro experiments that better resemble the in vivo reality. As a result, animal experiments can be reduced, and potent in vivo candidates will not be missed. It is important to gain a deeper knowledge about nanoparticle characteristics in physiological environment. In this context, the protein corona plays a crucial role. Its formation process including driving forces, kinetics, and influencing factors has to be explored in more detail. There exist different methods for the investigation of the protein corona and its impact on physico-chemical and biological properties of nanoparticles, which are compiled and critically reflected in this review article. The obtained information about the protein corona can be exploited to optimize nanoparticles for in vivo application. Still the translation from in vitro to in vivo remains challenging. Functional in vitro screening under physiological conditions such as in full serum, in 3D multicellular spheroids/organoids, or under flow conditions is recommended. Innovative in vivo screening using barcoded nanoparticles can simultaneously test more than hundred samples regarding biodistribution and functional delivery within a single mouse.

Synthetic cells in biomedical applications

Synthetic cells are engineered vesicles that can mimic one or more salient features of life. These features include directed localization, sense-and-respond behavior, gene expression, metabolism, and high stability. In nanomedicine, many of these features are desirable capabilities of drug delivery vehicles but are difficult to engineer. In this focus article, we discuss where synthetic cells offer unique advantages over nanoparticle and living cell therapies. We review progress in the engineering of the above life-like behaviors and how they are deployed in nanomedicine. Finally, we assess key challenges synthetic cells face before being deployed as drugs and suggest ways to overcome these challenges. This article is categorized under: Therapeutic Approaches and Drug Discovery > Emerging Technologies Biology-Inspired Nanomaterials > Lipid-Based Structures.

Progress and Hurdles of Therapeutic Nanosystems against Cancer

Nanomedicine against cancer, including diagnosis, prevention and treatment, has increased expectations for the solution of many biomedical challenges in the fight against this disease. In recent decades, an exhaustive design of nanosystems with high specificity, sensitivity and selectivity has been achieved due to a rigorous control over their physicochemical properties and an understanding of the nano–bio interface. However, despite the considerable progress that has been reached in this field, there are still different hurdles that limit the clinical application of these nanosystems, which, along with their possible solutions, have been reviewed in this work. Specifically, physiological processes as biological barriers and protein corona formation related to the administration routes, designing strategies to overcome these obstacles, promising new multifunctional nanotherapeutics, and recent clinical trials are presented in this review.

Nanoparticle protein corona evolution: from biological impact to biomarker discovery

Nanoparticles exposed to biological fluids such as blood, quickly interact with their surrounding milieu resulting in a biological coating that results in large part as a function of the physicochemical properties of the nanomaterial. The large nanoparticle surface area-to-volume ratio further augments binding of biological molecules and the resulting biomolecular or protein corona, once thought of as problematic biofouling, is now viewed as a rich source of biological information that can guide the development of nanomedicines. This review gives an overview of the utility of the protein corona in proteomic profiling and discusses how a better understanding of nano-bio interactions can accelerate the clinical translation of nanomedicines and facilitate the identification of disease-specific biomarkers. With the FDA requirement of the protein corona analysis of nanoparticles in place, it is envisaged that analyzing the protein corona of nanoparticles on a case-by-case basis can provide highly valuable nano-bio interface information that can aid and improve their clinical translation.

The impact of protein corona on the biological behavior of targeting nanomedicines

For successful translation of targeting nanomedicines from bench to bedside, it is vital to address their most common drawbacks namely rapid clearance and off-target accumulation. These complications evidently originate from a phenomenon called "protein corona (PC) formation" around the surface of targeting nanoparticles (NPs) which happens once they encounter the bloodstream and interact with plasma proteins with high collision frequency. This phenomenon endows the targeting nanomedicines with a different biological behavior followed by an unexpected fate, which is usually very different from what we commonly observe in vitro. In addition to the inherent physiochemical properties of NPs, the targeting ligands could also remarkably dictate the amount and type of adsorbed PC. As very limited studies have focused their attention on this particular factor, the present review is tasked to discuss the best simulated environment and latest characterization techniques applied to PC analysis. The effect of PC on the biological behavior of targeting NPs engineered with different targeting moieties is further discussed. Ultimately, the recent progresses in manipulation of nano-bio interfaces to achieve the most favorite therapeutic outcome are highlighted.

Multifunctional exosome-mimetics for targeted anti-glioblastoma therapy by manipulating protein corona

Targeted drug delivery to the glioblastoma (GBM) overcoming blood–brain barrier (BBB) has been challenging. Exosomes are promising vehicles for brain tumor drug delivery, but the production and purification hinder its application for nanomedicine. Besides, the formation of protein corona (PC) may affect the behaviour of nanocarriers. Here, multifunctional exosomes-mimetics (EM) are developed and decorated with angiopep-2 (Ang) for enhancing GBM drug delivery by manipulating PC. Docetaxel (DTX)-loaded EM with Ang modification (DTX@Ang-EM) show less absorption of serum proteins and phagocytosis by macrophages. Ang-EM show enhanced BBB penetration ability and targeting ability to the GBM. Ang-EM-mediated delivery increase the concentration of DTX in the tumor area. The multifunctional DTX@Ang-EM exhibits significant inhibition effects on orthotopic GBM growth with reduced side effects of the chemotherapeutic. Findings from this study indicate that the developed DTX@Ang-EM provide a new strategy for targeted brain drug delivery and GBM therapy.

Evolution of the protein corona affects macrophage polarization

When nanoparticles (NPs) come into contact with bioenvironments, a protein corona forms on the NP surface. Previous reports showed that the constituents of the corona change with time. However, how different protein corona compositions influence cells, especially immune cells, has received less attention. Macrophages are important immune cells that can be polarized into a pro-inflammatory (M1) or anti-inflammatory (M2) phenotype. In this study, AuNPs were incubated with human plasma for different periods to obtain time-related AuNP-coronas, and the influences of time-related AuNP-coronas on macrophage polarization were investigated. The macrophage morphology, biomarkers, cytokine secretion studies show that the pristine AuNPs and 4 h-AuNP-corona induced macrophage cells into M2 phenotype, while the co-incubation of 12 h-AuNP-corona and macrophage cells result in M1 phenotype. Further proteomic analysis showed that the compositions of protein corona were changing constantly after AuNPs contacted with plasma. When the incubation time increased to 12 h, the immune proteins in protein corona were increased significantly, which play a key role in modulation of the different macrophages polarization. Our findings demonstrated that plasma incubation time is an important parameter that needs to be taken into account in the study of nano-immune interactions and safe use of NPs in biological systems. Moreover, our finding can be a new efficient strategy for activating inflammatory or anti-inflammatory in medical treatment.

Endothelial cell membrane-based biosurface for targeted delivery to acute injury: analysis of leukocyte-mediated nanoparticle transportation

Mimicking and leveraging biological structures and materials provide important approaches to develop functional vehicles for drug delivery. Taking advantage of the affinity and adhesion between the activated endothelial cells and innate immune cells during inflammatory responses, hybrid polyester nanoparticles coated with endothelial cell membranes (EM-P) containing adhesion molecules were fabricated and their capability as vehicles to travel to the acute injury sites through leukocyte-mediated processes was investigated. The in vivo studies and quantitative analyses performed through the lung-inflammation mouse models demonstrated that the EM-Ps preferentially interacted with the neutrophils and monocytes in the circulation and the cellular membrane-based biosurface improved the nanoparticle transportation to the inflamed lung possibly via the motility of neutrophils. Utilizing the transgenic zebrafish model, the leukocyte-mediated transportation and biodistribution of EM-Ps were further visualized in real time at the whole-organism level. Endothelial membranes provided a new biosurface for developing biomimetic vehicles to allow the immune cell-mediated transportation and may enable advanced systems for active and highly efficient drug delivery.

Isolation methods commonly used to study the liposomal protein corona suffer from contamination issues

The liposomal protein corona has been the focus of numerous studies, but there is still no consensus regarding its extent and composition. Rather, the literature is full of conflicting reports on the matter. To elucidate whether there could be a methodological explanation for this, we here scrutinize the efficiency of three commonly used liposome isolation methods at isolating stealth liposomes from human plasma. Firstly, we show that size-exclusion chromatography (SEC) in its standard form is prone to isolating unbound protein material together with the liposomes, but also that the method may be optimized to mitigate this issue. Secondly, we demonstrate that SEC in combination with membrane ultrafiltration is no better at removing the unbound protein material than SEC alone. Thirdly, we show that centrifugation is not able to pellet the liposomes. Overall, our results suggest that previous research on the liposomal protein corona may have suffered from significant methodological problems, in particular related to contaminant proteins interfering with the analysis of the protein corona. We believe that the data presented here may help guide future research around this challenge to reach a converging understanding about the properties of the protein corona on liposomes. STATEMENT OF SIGNIFICANCE: Upon administration into the circulatory system, liposomal drug carriers encounter an environment rich in proteins. These proteins may adsorb to the liposomes to form what is known as the protein corona, potentially governing the interactions of the liposomes with tissues and cells. However, despite decades of intense research efforts, there is currently no clear understanding about the extent and composition of the liposomal protein corona, making it impossible to assess its mechanistic importance. Here we report that the methods commonly used to isolate liposomes from blood plasma or serum to study the protein corona are susceptible to protein contamination. This may be the underlying technical reason for the current confusion about the characteristics of the liposomal protein corona.

Biomimetic Nanoparticles as a Theranostic Tool for Traumatic Brain Injury

Traumatic brain injury (TBI) triggers both central and peripheral inflammatory responses. Existing pharmacological drugs are unable to effectively and quickly target the brain inflamed regions, setting up a major roadblock towards effective brain trauma treatments. Nanoparticles (NPs) have been used in multiple diseases as drug delivery tools with remarkable success due to their rapid diffusion and specificity in the target organ. Here, leukocyte-based biomimetic NPs are fabricated as a theranostic tool to directly access inflamed regions in a TBI mouse model. This NP systemic delivery is visualized using advanced in vivo imaging techniques, including intravital microscopy and in vivo imaging system. The results demonstrate selective targeting of NPs to the injured brain and increased NPs accumulation among the peripheral organs 24 h after TBI. Interestingly, increased microglial proliferation, decreased macrophage infiltration, and reduced brain lesion following the NPs treatments compared to sham vehicle-treated mice are also found. In summary, the results suggest that NPs represent a promising future theranostic tool for TBI treatment.

The Fate of Nanoparticles In Vivo and the Strategy of Designing Stealth Nanoparticle for Drug Delivery

Nano-drug delivery systems (Nano-DDS) offer powerful advantages in drug delivery and targeted therapy for diseases. Compared to the traditional drug formulations, Nano-DDS can increase solubility, biocompatibility, and reduce off-targeted side effects of free drugs. However, they still have some disadvantages that pose a limitation in reaching their full potential in clinical use. Protein adsorption in blood, activation of the complement system, and subsequent sequestration by the mononuclear phagocyte system (MPS) consequently result in nanoparticles (NPs) to be rapidly cleared from circulation. Therefore, NPs have low drug delivery efficiency. So, it is important to develop stealth NPs for reducing bio-nano interaction. In this review, we first conclude the interaction between NPs and biological environments, such as blood proteins and MPS, and factors influencing each other. Next, we will summarize the new strategies to reduce NPs protein adsorption and uptake by the MPS based on current knowledge of the bio-nano interaction. Further directions will also be highlighted for the development of biomimetic stealth nano-delivery systems by combining targeted strategies for a better therapeutic effect.

In vivo Protein Corona Formation: Characterizations, Effects on Engineered Nanoparticles' Biobehaviors, and Applications

Understanding the basic interactions between engineered nanoparticles (ENPs) and biological systems is essential for evaluating ENPs’ safety and developing better nanomedicine. Profound interactions between ENPs and biomolecules such as proteins are inevitable to occur when ENPs are administered or exposed to biological systems, for example, through intravenous injection, oral, or respiration. As a key component of these interactions, protein corona (PC) is immediately formed surrounding the outlayer of ENPs. PC formation is crucial because it gives ENPs a new biological identity by altering not only the physiochemical properties, but also the biobehaviors of ENPs. In the past two decades, most investigations about PC formation were carried out with in vitro systems which could not represent the true events occurring within in vivo systems. Most recently, studies of in vivo PC formation were reported, and it was found that the protein compositions and structures were very different from those formed in vitro. Herein, we provide an in-time review of the recent investigations of this in vivo PC formation of ENPs. In this review, commonly used characterization methods and compositions of in vivo PC are summarized firstly. Next, we highlight the impacts of the in vivo PC formation on absorption, blood circulation, biodistribution, metabolism, and toxicity of administered ENPs. We also introduce the applications of modulating in vivo PC formation in nanomedicine. We further discuss the challenges and future perspectives.

In vivo protein corona on nanoparticles: does the control of all material parameters orient the biological behavior?

Nanomaterials have a huge potential in research fields from nanomedicine to medical devices. However, surface modifications of nanoparticles (NPs) and thus of their physicochemical properties failed to predict their biological behavior. This requires investigating the "missing link" at the nano-bio interface. The protein corona (PC), the set of proteins binding to the NPs surface, plays a critical role in particle recognition by the innate immune system. Still, in vitro incubation offers a limited understanding of biological interactions and fails to explain the in vivo fate. To date, several reports explained the impact of PC in vitro but its applications in the clinical field have been very limited. Furthermore, PC is often considered as a biological barrier reducing the targeting efficiency of nano vehicles. But the protein binding can actually be controlled by altering PC both in vitro and in vivo. Analyzing PC in vivo could accordingly provide a deep understanding of its biological effect and speed up the transfer to clinical applications. This review demonstrates the need for clarifications on the effect of PC in vivo and the control of its behavior by changing its physicochemical properties. It unfolds the recent in vivo developments to understand mechanisms and challenges at the nano-bio interface. Finally, it reports recent advances in the in vivo PC to overcome and control the limitations of the in vitro PC by employing PC as a boosting resource to prolong the NPs half-life, to improve their formulations and thereby to increase its use for biomedical applications.

Membrane engineering of cell membrane biomimetic nanoparticles for nanoscale therapeutics

In recent years, cell membrane camouflaging technology has emerged as an important strategy of nanomedicine, and the modification on the membranes is also a promising approach to enhance the properties of the nanoparticles, such as cancer targeting, immune evasion, and phototherapy sensitivity. Indeed, diversified approaches have been exploited to re-engineer the membranes of nanoparticles in several studies. In this review, first we discuss direct modification strategy of cell membrane camouflaged nanoparticles (CM-NP) via noncovalent, covalent, and enzyme-involved methods. Second, we explore how the membranes of CM-NPs can be re-engineered at the cellular level using strategies such as genetic engineering and membranes fusion. Due to the innate biological properties and excellent biocompatibility, the functionalized cell membrane-camouflaged nanoparticles have been widely applied in the fields of drug delivery, imaging, detoxification, detection, and photoactivatable therapy.

Analysis of the Human Plasma Proteome Using Multi-Nanoparticle Protein Corona for Detection of Alzheimer's Disease

As the population affected by Alzheimer's disease (AD) grows, so does the need for a noninvasive and accurate diagnostic tool. Current research reveals that AD pathogenesis begins as early as decades before clinical symptoms. The unique properties of nanoparticles (NPs) may be exploited to develop noninvasive diagnostics for early detection of AD. After exposure of NPs to biological fluids, the NP surface is altered by an unbiased but selective and reproducible adsorption of biomolecules commonly referred to as the biomolecular corona or protein corona (PC). The discovery that the plasma proteome may be differentially altered during health and disease leads to the concept of disease-specific PCs. Herein, the disease-specific PCs formed around NPs in a multi-NPs platform are employed to successfully identify subtle changes in plasma protein patterns and detect AD (>92% specificity and ≈100% sensitivity). Similar discrimination power is achieved using banked plasma samples from a cohort of patients several years prior to their diagnosis with AD. With the nanoplatform's analytic ability to analyze pathological proteomic changes into a disease-specific identifier, this promising, noninvasive technology with implications for early detection and intervention could benefit not only patients with AD but other diseases as well.

Prunus spinosa Extract Loaded in Biomimetic Nanoparticles Evokes In Vitro Anti-Inflammatory and Wound Healing Activities

Prunus spinosa fruits (PSF) contain different phenolic compounds showing antioxidant and anti-inflammatory activities. Innovative drug delivery systems such as biomimetic nanoparticles could improve the activity of PSF extract by promoting (i) the protection of payload into the lipidic bilayer, (ii) increased accumulation to the diseased tissue due to specific targeting properties, (iii) improved biocompatibility, (iv) low toxicity and increased bioavailability. Using membrane proteins extracted from human monocyte cell line THP-1 cells and a mixture of phospholipids, we formulated two types of PSF-extract-loaded biomimetic vesicles differing from each other for the presence of either 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) or 1,2-dioleoyl-sn-glycero-3-phospho-(1'-rac-glycerol) (DOPG). The biological activity of free extract (PSF), compared to both types of extract-loaded vesicles (PSF-DOPCs and PSF-DOPGs) and empty vesicles (DOPCs and DOPGs), was evaluated in vitro on HUVEC cells. PSF-DOPCs showed preferential incorporation of the extract. When enriched into the nanovesicles, the extract showed a significantly increased anti-inflammatory activity, and a pronounced wound-healing effect (with PSF-DOPCs more efficient than PSF-DOPG) compared to free PSF. This innovative drug delivery system, combining nutraceutical active ingredients into a biomimetic formulation, represents a possible adjuvant therapy for the treatment of wound healing. This nanoplatform could be useful for the encapsulation/enrichment of other nutraceutical products with short stability and low bioavailability.