Debugging Nano-Bio Interfaces: Systematic Strategies to Accelerate Clinical Translation of Nanotechnologies

Implications of Biomolecular Corona for Molecular Imaging

The development of nanoparticle probes has opened up new possibilities for molecular imaging in the era of precision medicine. There are a wide range of nanoprobes that are being used for various modalities that have demonstrated promising potential in early detection, disease monitoring, and theranostics. However, the rate of successful clinical translation of the nanoprobes is very low and is affected by the lack of our understanding about nanoparticle interaction with biological fluids after systemic administration, thus representing an unmet clinical need. One of the poorly understood issues relates to the formation of biomolecular corona, a layer of biomolecules formed on the surface of nanoscale materials during their interactions with biological fluids. The biomolecular corona has several significant effects on the biodistribution of nanoprobes and their imaging ability by (i) reducing their targeting efficacy and (ii) affecting the intrinsic imaging properties (e.g., contrast capacity of magnetic nanoprobes). This review provides insights on the importance of considering biomolecular corona in the development of nanoprobes, which may enable their more efficient utilization for molecular imaging applications.

Neuroprotective Potential of Curcumin-Loaded Nanostructured Lipid Carrier in an Animal Model of Alzheimer's Disease: Behavioral and Biochemical Evidence

Alzheimer's disease (AD) is one of the most common neurodegenerative diseases and is caused by accumulation of amyloid-β (Aβ) peptide and is associated with neurological abnormalities in learning and memory. The protective role of curcumin on nerve cells, along with a potent antioxidant and free radical scavenging activity, has been widely studied. However, its low bioavailability and limited transport ability across the blood-brain barrier are two major drawbacks of its application in the treatment of different neurodegenerative diseases. The present study was designed to improve the effectiveness of curcumin in the treatment of Aβ-induced cognitive deficiencies in a rat model of AD by loading it into nanostructured lipid carriers (NLCs). The accumulation rate of curcumin (505.76±38.4 ng/g-1 h) in rat brain, as well as its serum levels, were significantly increased by using curcumin-loaded NLCs. The effective role of NLCs for brain delivery of curcumin was confirmed by reduced oxidative stress parameters (ROS formation, lipid peroxidation, and ADP/ATP ratio) in the hippocampal tissue and improvement of spatial memory. Also, histopathological studies revealed the potential of Cur-NLCs in decreasing the hallmarks of Aβ in AD in the animal model. The result of studying the neuroprotective potential of Cur-NLC in both pre-treatment and treatment modes showed that loading curcumin in NLCs is an effective strategy for increasing curcumin delivery to the brain and reducing Aβ-induced neurological abnormalities and memory defects and that it can be the basis for further studies in the area of AD prevention and treatment.

Effect of cell imprinting on viability and drug susceptibility of breast cancer cells to doxorubicin

This study demonstrates the effect of substrate's geometrical cues on viability and the efficacy of an anti-cancer drug, doxorubicin (DOX), on breast cancer cells. It is hypothesized that the surface topographical properties can mediate the cellular drug intake. Pseudo-three dimensional (3D) platforms were fabricated using imprinting technique from polydimethylsiloxane (PDMS) and gelatin methacryloyl (GelMA) hydrogel to recapitulate topography of cells' membranes. The cells exhibited higher viability on the cell-imprinted platforms for both PDMS and GelMA materials compared to the plain/flat counterparts. For instance, MCF7 cells showed a higher metabolic activity (11.9%) on MCF7-imprinted PDMS substrate than plain PDMS. The increased metabolic activity for the imprinted GelMA was about 44.2% compared to plain hydrogel. The DOX response of cells was monitored for 24 h. Although imprinted substrates demonstrated enhanced biocompatibility, the cultured cells were more susceptible to the drug compared to the plain substrates. In particular, MCF7 cells on imprinted PDMS and GelMA substrates showed 37% and 50% higher in cell death compared to the corresponding plain PDMS and GelMA, respectively. Interestingly, the drug susceptibility of the cells on the imprinted hydrogel was about 70% higher than the cells cultured on imprinted PDMS substrates. Having MCF7 cell-imprinted substrates, DOX responses of two other breast cancer cell lines, SKBR3 and ZR-75-1, were also evaluated. The results support that cell membrane curvature developed by multiscale topography is able to mediate intracellular signaling and drug intake. STATEMENT OF SIGNIFICANCE: Research in biological sciences and drug discovery mostly rely on two dimensional (2D) cell culture techniques which cannot provide a reliable physiologically relevant environment. Lack of extracellular matrix and a large shift in physicochemical properties of conventional 2D substrates can induce aberrant cellular behaviors. While chemical composition, topographical, and mechanical properties of substrates have remarkable impacts on drug susceptibility, gene expression, and protein synthesis, the most cell culture plates are from rigid and plain substrates. A number of (bio)polymeric 3D-platforms have been introduced to resemble innate cell microenvironment. However, their intricate culture protocols restrain their applications in demanding high-throughput drug screening. To address the above concerns, in the present study, a hydrogel-based pseudo-3D substrate with imprinted cell features has been introduced.

Magnetic Levitation Systems for Disease Diagnostics

Magnetic levitation (MagLev) is a well-documented, robust technique for density measurements and separations. Although the potential of MagLev as an emerging tool in biotechnology has been recently investigated, the practical use of MagLev in diagnosis and disease detection merits further attention. This review highlights the diagnostic capacity of a simple and portable MagLev system and the possibilities and limitations of the MagLev technique for density-based separation, classification, and manipulation of soft matter and biological systems (e.g., cells, proteins), which in turn may pave the way for the discovery of disease-specific biomarkers.

Light-Activated Liposomes Coated with Hyaluronic Acid as a Potential Drug Delivery System

Light-activated liposomes permit site and time-specific drug delivery to ocular and systemic targets. We combined a light activation technology based on indocyanine green with a hyaluronic acid (HA) coating by synthesizing HA-lipid conjugates. HA is an endogenous vitreal polysaccharide and a potential targeting moiety to cluster of differentiation 44 (CD44)-expressing cells. Light-activated drug release from 100 nm HA-coated liposomes was functional in buffer, plasma, and vitreous samples. The HA-coating improved stability in plasma compared to polyethylene glycol (PEG)-coated liposomes. Liposomal protein coronas on HA- and PEG-coated liposomes after dynamic exposure to undiluted human plasma and porcine vitreous samples were hydrophilic and negatively charged, thicker in plasma (~5 nm hard, ~10 nm soft coronas) than in vitreous (~2 nm hard, ~3 nm soft coronas) samples. Their compositions were dependent on liposome formulation and surface charge in plasma but not in vitreous samples. Compared to the PEG coating, the HA-coated liposomes bound more proteins in vitreous samples and enriched proteins related to collagen interactions, possibly explaining their slightly reduced vitreal mobility. The properties of the most abundant proteins did not correlate with liposome size or charge, but included proteins with surfactant and immune system functions in plasma and vitreous samples. The HA-coated light-activated liposomes are a functional and promising alternative for intravenous and ocular drug delivery.

Engineering at the nano-bio interface: harnessing the protein corona towards nanoparticle design and function

Unpredictable and uncontrollable protein adsorption on nanoparticles remains a considerable challenge to achieving effective application of nanotechnologies within biological environments. Nevertheless, engineered nanoparticles offer unprecedented functionality and control in probing and altering biological systems. In this review, we highlight recent advances in harnessing the "protein corona" formed on nanoparticles as a handle to tune functional properties of the protein-nanoparticle complex. Towards this end, we first review nanoparticle properties that influence protein adsorption and design strategies to facilitate selective corona formation, with the corresponding characterization techniques. We next focus on literature detailing corona-mediated functionalities, including stealth to avoid recognition and sequestration while in circulation, targeting of predetermined in vivo locations, and controlled activation once localized to the intended biological compartment. We conclude with a discussion of biocompatibility outcomes for these protein-nanoparticle complexes applied in vivo. While formation of the nanoparticle-corona complex may impede our control over its use for the projected nanobiotechnology application, it concurrently presents an opportunity to create improved protein-nanoparticle architectures by exploiting natural or guiding selective protein adsorption to the nanoparticle surface.

A custom-made functionalization method to control the biological identity of nanomaterials

Here we propose a one-step strategy to endow nanomaterials with a custom-designed bio-identity. This study designs a universal 'nanomaterial binding domain' that can be genetically attached to any protein ensuring precise and spontaneous protein orientation. We demonstrate how, despite the simplicity of the method, the bioconjugation achieved: (i) is highly efficient, even in the presence of competing proteins, (ii) is stable at extreme physiological conditions (pH ranges 5.2-9.0; NaCl concentrations 0-1 M); (iii) prevents unwanted protein biofouling days after incubation in biologically-relevant conditions; and finally, (iv) avoids nanoparticle interaction with promiscuous unspecific receptors. In summary, this protein biocoating technique, applicable to a wide array of nano-designs, integrates material science and molecular biology procedures to create hybrid nanodevices with well-defined surfaces and predictable biological behaviors, opening a chapter in precision nanodiagnostics, nanosensing or nanotherapeutic applications.

Hypochlorite and visible-light irradiation affect the transformation and toxicity of graphene oxide

Graphene oxide (GO) that has many advanced properties, has been applied in various fields, such as water treatments and removal of contaminations. Hypochlorite is widely used in water treatments. However, the effects of hypochlorite on the transformations and risks of GO, and the toxicological responses remain largely unknown, especially under visible-light irradiation. The present work found that visible-light irradiation promoted the breakdown of sp² structures of GO by hypochlorite, producing alkanes and arenes with short carbon skeletons. Compared to oxygen-containing radicals, chlorine-related radicals contributed to the breakdown of carbon atomic rings of GO. Compared to pristine GO, the transformed GO inhibited algal reproduction, reduced photosynthesis, and promoted oxidative stress and membrane permeability. Substantial plasmolysis and increased numbers of starch grains were observed in the exposure groups. Metabolomics analysis found that oxidative stress and increased membrane permeability linked to downregulated proline. The downregulated pathways of alanine, aspartate and glutamate metabolism were associated with the inhibition of algal reproduction. The downregulated pathways related to protein synthesis and the secondary metabolism explained the strong toxicity induced by GO with hypochlorite and visible-light irradiation. The above results provide insight into the safety assessment of GO.

The role of human serum and solution chemistry in fibrinogen peptide-nanoparticle interactions

In living systems, the biomolecules that coat nanoparticles (NPs) alter the NP biological identity and response. Although some biomolecules are more effective in mediating NP stability or biological fate, it is difficult to monitor an individual biomolecule within the complexity of the biota. To understand the dependence of protein-NP interactions on common variations in blood, we have evaluated binding between silica NPs and a model gamma-fibrinogen (GF) peptide. Fibrinogen is commonly identified within the protein corona fingerprint of human serum, but its abundance on the NP varies. To assess the relative importance of human serum and solution conditions, GF peptide and silica NP interactions were evaluated with and without serum across pH, NaCl concentrations, and glucose concentrations. Initial evaluation of the GF peptide and silica NP complexes using circular dichroism and dynamic light scattering show little change in the secondary structure of the peptide and no significant agglomeration of NPs, suggesting peptide-NP complexes are stable across study conditions. Fluorescence anisotropy was used to monitor GF peptide-NP binding. Both with and without serum, binding constants for the gamma-fibrinogen peptide vary significantly upon addition of diluted HS (1:500) and 29 mM sodium chloride. Yet, results indicated that gamma-fibrinogen binding interactions with silica NPs are comparatively insensitive to physiologically relevant pH changes and dramatic increases in glucose concentrations. Results highlight the importance of blood chemistries, which vary across individuals and disease states, in mediating protein corona formation.

Gut microbiota and cardiovascular disease: opportunities and challenges

Coronary artery disease (CAD) is the most common health problem worldwide and remains the leading cause of morbidity and mortality. Over the past decade, it has become clear that the inhabitants of our gut, the gut microbiota, play a vital role in human metabolism, immunity, and reactions to diseases, including CAD. Although correlations have been shown between CAD and the gut microbiota, demonstration of potential causal relationships is much more complex and challenging. In this review, we will discuss the potential direct and indirect causal roots between gut microbiota and CAD development via microbial metabolites and interaction with the immune system. Uncovering the causal relationship of gut microbiota and CAD development can lead to novel microbiome-based preventative and therapeutic interventions. However, an interdisciplinary approach is required to shed light on gut bacterial-mediated mechanisms (e.g., using advanced nanomedicine technologies and incorporation of demographic factors such as age, sex, and ethnicity) to enable efficacious and high-precision preventative and therapeutic strategies for CAD.

Impact of plasma concentration of transferrin on targeting capacity of nanoparticles

It is becoming increasingly accepted that various diseases have a capacity to alter the composition of plasma proteins. This alteration in protein composition may consequently change the targeting capacity of nanoparticles (NPs). In this study, the impact of a model targeting ligand's (i.e., Transferrin; Tf) concentration in human plasma on the targeting capacity of gold NPs (Au NPs), pre-conjugated with Tf, is investigated. Our findings demonstrate that the protein corona formation by both healthy and Tf depleted human plasma diminishes the targeting efficacy of Au NPs within human cancer cells despite a preservation of targeting ability by plasma with excess Tf (10-fold). Moreover, the plasma samples obtained from patients with various Tf levels (e.g., thalassemia major, sickle cell anemia, aplastic anemia, and iron deficiency anemia) have affected the accessibility of the targeting Tf in the corona layer and subsequently affected their targeting ability, which emphasizes the critical role of disease-specific protein corona on the efficacy of Au NPs. Ultimately, variations of protein concentration (e.g., due to disease occurrence and progress) in plasma affect its recruiting in corona formation, and in turn, affect the targeting and therapeutic efficacies of Au NPs.

Mapping the heterogeneity of protein corona by ex vivo magnetic levitation

In the past decade, we witnessed limited success in the clinical translation of therapeutic nanoparticles (NPs). One of the main reasons for this limited success is our poor understanding of the biological identity of NPs. Herein, we report magnetic levitation (MagLev) as a complementary analytical tool to investigate the homogeneity of the created protein corona (PC) coated NPs through an ex vivo model. Our results demonstrate that the MagLev system not only has the capacity to separate corona coated NPs, but also enables us to study the homogeneity/heterogeneity of the PC. Our findings suggest that current ex vivo isolation methods cause a heterogeneous coverage of PC profiles at the surface of NPs. The MagLev technique, therefore, would be instrumental in identifying and separating fully PC coated NPs which, in turn, enables us to achieve more accurate information on protein corona composition. Ultimately, we believe that the MagLev technique can be used for the fast screening of the homogeneity of corona coated NPs before quantitative analysis of the corona profile/composition, hence definitely improving our fundamental understanding of nano-bio interfaces.

Corona of Thorns: The Surface Chemistry-Mediated Protein Corona Perturbs the Recognition and Immune Response of Macrophages

The significance of protein coronas on the biological fates of nanoparticles has been widely recognized. Therefore, the alterations on biological effects caused by protein coronas need systemic study and interpretation to design novel safe and efficient nanomedicines. In the present study, we present a comprehensive quantitative analysis of the protein coronas on gold nanorods  modified with various surface ligands of different chemical compositions and charges. The design of surface ligands is of utmost importance for the functionalization of nanoparticles, and further, the ligand-induced biological identity determines the fate of nanoparticles in the human body. We found that the surface chemistry influences the composition of the protein corona more profoundly than surface charge. Since the first and most important challenge for administrated nanomedicines is navigating the interaction with macrophages, we further investigated how the surface chemistry-induced specific protein corona affects the phagocytosis and immune responses of macrophages exposed to the corona-nanoparticle complexes. Our results reveal that the protein corona alters the internalization pathways of gold nanorods by macrophages via the interactions of the predominant coronal proteins with specific receptors on the cell membrane. The cytokine secretion profile of macrophages is also highly dependent on the adsorption pattern of the protein corona. The more abundant proteins involved in immune responses, such as acute phase, complement, and tissue leakage proteins, present in the acquired nanoparticle corona, the more macrophage interleukin-1β (IL-1β) released is stimulated. The ligand-protein corona composition-immune response coefficient analysis may serve next-generation nanomedicines with high efficiency and good safety for better clinical translation.

Novel therapeutic strategies for Alzheimer's disease: Implications from cell-based therapy and nanotherapy

Alzheimer's disease (AD) is a multifactorial neurodegenerative disease which leads to progressive dysfunction of cognition, memory and learning in elderly people. Common therapeutic agents are not only inadequate to suppress the progression of AD pathogenesis but also produce deleterious side effects; hence, development of alternative therapies is required to specifically suppress complications of AD. The current review provides a commentary on conventional as well as novel therapeutic approaches with an emphasis on stem cell and nano-based therapies for improvement and management of AD pathogenesis. According to our overview of the current literature, AD is a multi-factorial disorder with various pathogenic trajectories; hence, a multifunctional strategy to create effective neuroprotective agents is required to treat this disorder.

Prediction of protein corona on nanomaterials by machine learning using novel descriptors

Effective in silico methods to predict protein corona compositions on engineered nanomaterials (ENMs) could help elucidate the biological outcomes of ENMs in biosystems without the need for conducting lengthy experiments for corona characterization. However, the physicochemical properties of ENMs, used as the descriptors in current modeling methods, are insufficient to represent the complex interactions between ENMs and proteins. Herein, we utilized the fluorescence change (FC) from fluorescamine labeling on a protein, with or without the presence of the ENM, as a novel descriptor of the ENM to build machine learning models for corona formation. FCs were significantly correlated with the abundance of the corresponding proteins in the corona on diverse classes of ENMs, including metal and metal oxides, nanocellulose, and 2D ENMs. Prediction models established by the random forest algorithm using FCs as the ENM descriptors showed better performance than the conventional descriptors, such as ENM size and surface charge, in the prediction of corona formation. Moreover, they were able to predict protein corona formation on ENMs with very heterogeneous properties. We believe this novel descriptor can improve in silico studies of corona formation, leading to a better understanding on the protein adsorption behaviors of diverse ENMs in different biological matrices. Such information is essential for gaining a comprehensive view of how ENMs interact with biological systems in ENM safety and sustainability assessments.

A mechanistic explanation of the inhibitory role of the protein corona on liposomal gene expression

The past three decades have witnessed fast advances in the use of cationic liposome-DNA complexes (lipoplexes) for gene delivery applications. However, no lipoplex formulation has reached into the clinical practice so far. The primary drawback limiting clinical use of lipoplexes is the lack of mechanistic understanding of their low transfection efficiency (TE) in vivo. In physiological environments, lipoplexes are coated by a protein corona (PC) that mediates the interactions with the cell machinery. Here we show that the formation of PC can change the interactions of multicomponent (MC) lipoplexes with our cell model (i.e., HeLa). At the highest lipoplex concentration, the formation of PC can reduce the TE of MC lipoplexes from 60% to <5%. Combining dynamic light scattering and synchrotron small-angle X-ray scattering (SAXS), we clarify that the formation of PC modifies physical-chemical properties of MC lipoplexes so as to affect their TE. Moreover, we examined single transfection barriers by a combination of fluorescence-activated cell sorting, single-cell real-time fluorescence confocal microscopy, and synchrotron SAXS. We demonstrate that PC formation has the ability to modify the relative contribution of caveolae-mediated endocytosis and macropinocytosis in lipoplexes uptake, in favor of the latter, increasing accumulation of PC-decorated lipoplexes into degradative lysosomal compartments. Finally, we report evidences that PC reduces the structural stability of lipoplexes against solubilization by cellular lipids, likely favoring premature DNA release and cytosolic digestion by DNAase. These combined effects revealed here offer a comprehensive mechanistic explanation on the reason behind reduction in gene expression of MC lipoplexes.

Nanoscale Technologies for Prevention and Treatment of Heart Failure: Challenges and Opportunities

The adult myocardium has a limited regenerative capacity following heart injury, and the lost cells are primarily replaced by fibrotic scar tissue. Suboptimal efficiency of current clinical therapies to resurrect the infarcted heart results in injured heart enlargement and remodeling to maintain its physiological functions. These remodeling processes ultimately leads to ischemic cardiomyopathy and heart failure (HF). Recent therapeutic approaches (e.g., regenerative and nanomedicine) have shown promise to prevent HF postmyocardial infarction in animal models. However, these preclinical, clinical, and technological advancements have yet to yield substantial enhancements in the survival rate and quality of life of patients with severe ischemic injuries. This could be attributed largely to the considerable gap in knowledge between clinicians and nanobioengineers. Development of highly effective cardiac regenerative therapies requires connecting and coordinating multiple fields, including cardiology, cellular and molecular biology, biochemistry and chemistry, and mechanical and materials sciences, among others. This review is particularly intended to bridge the knowledge gap between cardiologists and regenerative nanomedicine experts. Establishing this multidisciplinary knowledge base may help pave the way for developing novel, safer, and more effective approaches that will enable the medical community to reduce morbidity and mortality in HF patients.

Brain-targeted enzyme-loaded nanoparticles: A breach through the blood-brain barrier for enzyme replacement therapy in Krabbe disease

Lysosomal storage disorders (LSDs) result from an enzyme deficiency within lysosomes. The systemic administration of the missing enzyme, however, is not effective in the case of LSDs with central nervous system (CNS)-involvement. Here, an enzyme delivery system based on the encapsulation of cross-linked enzyme aggregates (CLEAs) into poly-(lactide-co-glycolide) (PLGA) nanoparticles (NPs) functionalized with brain targeting peptides (Ang2, g7 or Tf2) is demonstrated for Krabbe disease, a neurodegenerative LSD caused by galactosylceramidase (GALC) deficiency. We first synthesize and characterize Ang2-, g7- and Tf2-targeted GALC CLEA NPs. We study NP cell trafficking and capability to reinstate enzymatic activity in vitro. Then, we successfully test our formulations in the Twitcher mouse. We report enzymatic activity measurements in the nervous system and in accumulation districts upon intraperitoneal injections, demonstrating activity recovery in the brain up to the unaffected mice level. Together, these results open new therapeutic perspectives for all LSDs with major CNS-involvement.

Zebrafish as a preclinical in vivo screening model for nanomedicines

The interactions of nanomedicines with biological environments is heavily influenced by their physicochemical properties. Formulation design and optimization are therefore key steps towards successful nanomedicine development. Unfortunately, detailed assessment of nanomedicine formulations, at a macromolecular level, in rodents is severely limited by the restricted imaging possibilities within these animals. Moreover, rodent in vivo studies are time consuming and expensive, limiting the number of formulations that can be practically assessed in any one study. Consequently, screening and optimisation of nanomedicine formulations is most commonly performed in surrogate biological model systems, such as human-derived cell cultures. However, despite the time and cost advantages of classical in vitro models, these artificial systems fail to reflect and mimic the complex biological situation a nanomedicine will encounter in vivo. This has acutely hampered the selection of potentially successful nanomedicines for subsequent rodent in vivo studies. Recently, zebrafish have emerged as a promising in vivo model, within nanomedicine development pipelines, by offering opportunities to quickly screen nanomedicines under in vivo conditions and in a cost-effective manner so as to bridge the current gap between in vitro and rodent studies. In this review, we outline several advantageous features of the zebrafish model, such as biological conservation, imaging modalities, availability of genetic tools and disease models, as well as their various applications in nanomedicine development. Critical experimental parameters are discussed and the most beneficial applications of the zebrafish model, in the context of nanomedicine development, are highlighted.

Nanomaterials for bone tissue regeneration: updates and future perspectives

Joint replacement and bone reconstructive surgeries are on the rise globally. Current strategies for implants and bone regeneration are associated with poor integration and healing resulting in repeated surgeries. A multidisciplinary approach involving basic biological sciences, tissue engineering, regenerative medicine and clinical research is required to overcome this problem. Considering the nanostructured nature of bone, expertise and resources available through recent advancements in nanobiotechnology enable researchers to design and fabricate devices and drug delivery systems at the nanoscale to be more compatible with the bone tissue environment. The focus of this review is to present the recent progress made in the rationale and design of nanomaterials for tissue engineering and drug delivery relevant to bone regeneration.

Effect of Cell Age on Uptake and Toxicity of Nanoparticles: The Overlooked Factor at the Nanobio Interface

Clinical translation of nanotechnologies has limited success, at least in part, due to the existence of several overlooked factors on the nature of the nanosystem (e.g., physicochemical properties of nanoparticles), nanobio interfaces (e.g., protein corona composition), and the cellular characteristics (e.g., cell type). In the past decade, several ignored factors including personalized and disease-specific protein corona (a layer of formed biomolecules at the surface of nanoparticles upon their entrance into a biological fluid), incubating temperature, local temperature gradient, cell shape, and cell sex has been introduced. Here, it was hypothesized and validated cell age as another overlooked factor in the field of nanomedicine. To test our hypothesis, cellular toxicity and uptake profiles of our model nanoparticles (i.e., PEGylated quantum dots, QDs) were probed in young and senescent cells (i.e., IMR90 fibroblast cells from human fetal lung and CCD841CoN epithelial cells from human fetal colon) and the outcomes revealed substantial dependency of cell-nanoparticles interactions to the cell age. For example, it was observed that the PEGylated QDs were acutely toxic to senescent IMR90 and CCD841CoN cells, leading to lysosomal membrane permeabilization which caused cell necrosis; in contrast, the young cells were resilient to the exact same amount of QDs and the same incubation time. It was also found that the formation of protein corona could delay the QDs' toxicity on senescent cells. These findings suggest that the cellular aging process have a capacity to cause deteriorative effects on their organelles and normal functions. The outcomes of this study suggest the proof-of-concept that cell age may have critical role in biosystem responses to nanoparticle technologies. Therefore, the effect of cell age should be carefully considered on the nanobio interactions and the information about cellular age (e.g., passage number and age of the cell donor) should be included in the nanomedicine papers to facilitate clinical translation of nanotechnologies and to help scientists to better design and produce safe and efficient diagnostic/therapeutic age-specific nanoparticles.

Best practice in reporting corona studies: Minimum information about Nanomaterial Biocorona Experiments (MINBE)

Characterisation of the adsorption of biomolecules, or a biocorona, on nanomaterials has proliferated in the past 10 years, as protein corona studies provide molecular level insight into mechanisms of cellular recognition, uptake, and toxicity of nanomaterials. At the crossroads of two rapidly evolving orthogonal fields, nanoscience and proteomics, the interdisciplinarity of protein corona studies creates challenges for experimental design and reporting. Here we propose a flexible checklist for experimental design and reporting guidelines to outline Minimum Information about Nanomaterial Biocorona Experiments (MINBE). The checklist for experimental design, compiled after review of reporting within the protein corona literature, provides researchers with prompts to ensure best practice experimental approaches for each stage of the workflow, collated from the nanoscience, proteomics, and bioinformatics fields. Reporting guidelines are also assembled from established sources, integrated to span the entire workflow and extended and modified to aid interdisciplinary researchers in the most challenging stages of the workflow. Where appropriate, de novo guidelines to address areas specific to protein corona studies, including exposure conditions and isolation of adsorbed proteins, were written. The MINBE guidelines provide protein corona researchers with a conduit between materials science techniques and proteomics. Implementation of these guidelines is anticipated to catalyse enhanced quality, impact, and extent of data mining and computational modelling of protein corona composition and its role in nanosafety and nanomedicine. Furthermore, high quality experimental design and reporting in the bio-nanosciences will enhance the next phase of targeted nanomedicines and sustainable nanotechnologies.

Functionalized nanographene sheets with high antiviral activity through synergistic electrostatic and hydrophobic interactions

As resistance to traditional drugs emerges for treatment of virus infections, the need for new methods for virus inhibition increases. Graphene derivatives with large surface areas have shown strong activity against different viruses. However, the inability of current synthetic protocols to accurately manipulate the structure of graphene sheets in order to control their antiviral activity remains a major challenge. In this work, a series of graphene derivatives with defined polyglycerol sulfate and fatty amine functionalities have been synthesized and their interactions with herpes simplex virus type 1 (HSV-1) are investigated. While electrostatic interactions between polyglycerol sulfate and virus particles trigger the binding of graphene to virus, alkyl chains induce a high antiviral activity by secondary hydrophobic interactions. Among graphene sheets with a broad range of alkyl chains, (C3-C18), the C12-functionalized sheets showed the highest antiviral activity, indicating the optimum synergistic effect between electrostatic and hydrophobic interactions, but this derivative was toxic against the Vero cell line. In contrast, sheets functionalized with C6- and C9-alkyl chains showed low toxicity against Vero cells and a synergistic inhibition of HSV-1. This study shows that antiviral agents against HSV-1 can be obtained by controlled and stepwise functionalization of graphene sheets and may be developed into antiviral agents for future biomedical applications.

Potential applications of nanoparticles for tumor microenvironment remodeling to ameliorate cancer immunotherapy

In recent years, researchers have made significant innovations in the field of tumor immunotherapy based on the knowledge of biology, oncology, and immunology. Tumor immunotherapy involves the use of immune checkpoint inhibitors and CAR (chimeric antigen receptor)-T cell therapy. As compared with conventional chemotherapy, immunotherapy is a potential approach to induce a more powerful immune response against tumor in the patient suffering from the advanced stage malignancy. Regardless of the developments made, a large number of clinical studies have confirmed that a substantial number of cancer patients still demonstrate non-responsiveness to immunotherapy, mainly due to the immunomodulating interactions of tumor cells with the immunosuppressive tumor microenvironment (iTME). It leads to immune tolerance of tumors and influences the efficacy of immunotherapy. This immune failure could be attributed to a complex immunosuppressive network comprising stromal and inflammatory cells, vessel system, ECM (extracellular matrix) and the cytokines released in tumor microenvironment (TME). The antitumor immune activity can be enhanced at different stages of tumor development by selective suppression of inhibitory pathways in the TME. This specific task can be achieved by using nano-sized drug delivery tools which are specific in their action and biocompatible in nature. Several recent studies have described the use of nanoparticles for iTME remodeling through the specific elimination of immunosuppressive cells, obstructing immune checkpoints, promotion of inflammatory cytokines, and amending the regulatory cells of the immune system. The efficacy of current immunotherapy can be improved by nanoparticle-mediated remodeling of iTME.

Nanoparticles Targeting Macrophages as Potential Clinical Therapeutic Agents Against Cancer and Inflammation

With the development of nanotechnology, significant progress has been made in the design, and manufacture of nanoparticles (NPs) for use in clinical treatments. Recent increases in our understanding of the central role of macrophages in the context of inflammation and cancer have reinvigorated interest in macrophages as drug targets. Macrophages play an integral role in maintaining the steady state of the immune system and are involved in cancer and inflammation processes. Thus, NPs tailored to accurately target macrophages have the potential to transform disease treatment. Herein, we first present a brief background information of NPs as drug carriers, including but not limited to the types of nanomaterials, their biological properties and their advantages in clinical application. Then, macrophage effector mechanisms and recent NPs-based strategies aimed at targeting macrophages by eliminating or re-educating macrophages in inflammation and cancer are summarized. Additionally, the development of nanocarriers targeting macrophages for disease diagnosis is also discussed. Finally, the significance of macrophage-targeting nanomedicine is highlighted, with the goal of facilitating future clinical translation.

Construction and Evaluation of a Self-Calibrating Multiresponse and Multifunctional Graphene Biosensor

Recently, many studies have been focused on the development of graphene-based biosensors. However, they rely on one type of signal and need to be calibrated by other techniques. In this study, a nonenzymatic graphene-based biosensor has been designed and constructed. Its ability to detect glucose and Escherichia coli by three different types of signals has been investigated. For its preparation, dopamine-functionalized polyethylene glycol and 2,5-thiophenediylbisboronic acid were conjugated onto the surface of graphene sheets by nitrene [2 + 1] cycloaddition and condensation reactions, respectively. Multivalent interactions between boronic acid segments and biosystems consequently increased the quantifiable fluorescence emission and UV absorption of dopamine segments. Additionally, changing the electrochemical behavior of the functionalized graphene sheets was possible and resulted in a measurable output signal. Conjugation of mannose onto the surface of the biosensor improved its magnitude of signals and specificity for sensing E. coli in a complex medium. The efficiency and accuracy of each signal was monitored by others, which resulted in a real-time self-calibrating biosensor. Taking advantage of the versatility of the three different indicators, including florescence, UV, and electrochemistry, the functionalized graphene sheets have been used as self-regulating biosensors to detect a variety of biosystems with a high accuracy and specificity in a short time.

The biomolecular corona of gold nanoparticles in a controlled microfluidic environment

Nanoparticles (NPs) exposed to biological media are coated by proteins and other biomolecules forming a biomolecular corona (BC) on the particle surface. Recent studies have shown that shear stress as that created by laminar fluid flow generates more complex coronas with systematic changes in composition with respect to counterparts formed under static incubation. However, in most studies reported so far, dynamic environments have been produced by peristaltic pumps and comparing experimental results appears challenging. On the other side, generating shear stress by microfluidic devices could help to remove user variability and ensure better reproducibility of experimental data. This study was therefore aimed at exploring formation of NP-BC in a microfluidic environment. To this end, 100 nm gold nanoparticles and human plasma (HP) were used as models for nano-formulation and biological medium. We injected gold nanoparticles and HP in each of the islets of a remote-controlled microfluidic cartridge. Static incubation was used as a reference. BC-decorated NPs were thoroughly characterized by dynamic light scattering (DLS), micro-electrophoresis (ME), sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS PAGE) and nano-liquid chromatography tandem mass spectrometry (nano-LC MS/MS). By varying the incubation time from 30 s to 2.5 min we demonstrate that BC is already determined by the earliest exposure time point and does not appreciably evolve in time. DLS and ME results demonstrate that the BC formed in a microfluidic chip is thicker and more negatively charged than its counterpart formed under static incubation. SDS-PAGE and nano-LC MS/MS revealed that the incubation procedure had a major effect on BC composition. As an example, immunoglobulins are the most abundant plasma proteins of the BC generated in a microfluidic environment (relative protein abundance ∼30%), while tissue leakage proteins (relative protein abundance ∼26%) are the most enriched proteins when the BC is formed upon static incubation. Potential implications in emerging biomedical research arenas are discussed.

The trip of a drug inside the body: From a lipid-based nanocarrier to a target cell

To date, enormous investigations have been conducted to enhance medicines' target-oriented delivery to improve their therapeutic index. In this regard, lipid-based carrier system might have been regarded as prime delivery systems that are very close to the naturally cell-derived vesicles used for biomolecular communication among cells from occasionally remote tissues. Upon examination of the literature, we found a chasm between groups of investigations in drug pharmaceutics and thought that maybe holistic research could provide better information with respect to drug delivery inside the body, especially when they are going to be injected directly into the bloodstream for systemic distribution. While a collection of older research in most cases dealt with the determination of drug partition coefficient between the aqueous and cell membrane compartments, the link has been overlooked in newer investigations that were mostly focused on drug formulation optimization and their association with particle biodistribution. This gap in the literature motivated us to present the current opinion paper, in which drug physicochemical properties like drug lipophilicity/hydrophilicity is considered as an important element in designing drug-carrying liposomes or micelles. How a hypothetical high throughput cell-embedded chromatographic technique might help to investigate a nanocarrier tissue distribution and to design 'multi-epitope grafted lipid-based drug carrier systems' are discussed. Whenever we would need support for our opinions, we have provided analogy from hydrophobic biomolecules like cholesterol, steroid hormones, and sex hormones and encouraged readers to consider our principle hypothesis: If these molecules could reach their targets far away from the site of production, then a large list of hydrophobic drugs could be delivered to their targets using the same principles.

Multiscale Molecular Dynamics Simulation of Multiple Protein Adsorption on Gold Nanoparticles

A multiscale molecular dynamics simulation study has been carried out in order to provide in-depth information on the adsorption of hemoglobin, myoglobin, and trypsin over citrate-capped AuNPs of 15 nm diameter. In particular, determinants for single proteins adsorption and simultaneous adsorption of the three types of proteins considered have been studied by Coarse-Grained and Meso-Scale molecular simulations, respectively. The results, discussed in the light of the controversial experimental data reported in the current experimental literature, have provided a detailed description of the (i) recognition process, (ii) number of proteins involved in the early stages of corona formation, (iii) protein competition for AuNP adsorption, (iv) interaction modalities between AuNP and protein binding sites, and (v) protein structural preservation and alteration.

Effect of molecular crowding on the biological identity of liposomes: an overlooked factor at the bio-nano interface

Once embedded in a physiological environment, the surface of nanoparticles (NPs) gets covered with a biomolecular corona (BC) that alters their synthetic characteristics and subsequently gives them a peculiar biological identity. Despite recent studies having clarified the role of NP composition, surface chemistry and biological source (e.g., human/animal serum or plasma) in the formation of the BC, little is known about the possible impact of molecular crowding. To fill this gap, we used a cationic liposomal formulation as a model system and studied its biological identity upon incubation with human plasma, at a fixed liposome-to-plasma volume ratio and different concentrations. We carried out dynamic light scattering measurements to quantify the size and zeta potential of the investigated systems and gel electrophoresis to evaluate the composition of the corresponding coronas. Our findings suggest that NP stability may be compromised by molecular crowding, but the corona composition is stable over a wide range of concentrations, which extend over more than two orders of magnitude. As the biological identity of NPs eventually determines their final fate in vivo, we predict that this study could contribute to the development of a safe and effective nanosystem for the targeted delivery of therapeutic agents.

In vitro and in silico protein corona formation evaluation of curcumin and capsaicin loaded-solid lipid nanoparticles

Nanotechnology has been an important tool for the production of nanoparticles with controlled release of drugs for therapeutic applications. Here, we produced solid lipid nanoparticles (SLN) loaded with curcumin and capsaicin (NCC) following the overarching goals of green chemistry. Currently, besides evaluating the composition, and size of these, it is necessary to understand the interactions between nanoparticles and the biomolecules present in the biological medium. For this, assays were conducted in order to evaluate the potential formation of the protein 'corona', and to better understand the results obtained in vitro, we also performed an interaction study, in silico, between the NCC components and the main serum protein, albumin. In the first hour of contact between the NCC and the culture medium showed fluctuation in the diameter of the NCC. However, after 24 and 48 h of the incubation period, all NCC concentrations showed an increase in size, which can be attributed to plasma protein adsorption. Since, hard corona takes a few seconds, while the soft corona can be formed in minutes up to a few hours. On the other hand, best docking binding-poses of interaction for the formed docking complexes evaluated suggest interactions following the docking affinity like free energy FEB (Tween 80-bovine serum albumin) ≈ FEB (Span 80-bovine serum albumin) showing a pharmacodynamic pattern based in non-covalent hydrophobic interactions with the bovine serum albumin binding-site. Our in silico results clarify and reinforce our in vitro findings of corona formation, which represents the real interaction with cell membranes in vivo.

Nano-Cell Interactions of Non-Cationic Bionanomaterials

Advances in nanotechnology have empowered the design of bionanomaterials by assembling different types of natural biomolecules (e.g., nucleic acids, proteins, and lipids) as building blocks into nanoparticles (NPs) of 1-100 nm in diameter. Such bionanomaterials form the basis of useful nanomedicine applications, such as targeted delivery, gene regulation, molecular diagnostics, and immunomodulation. To achieve optimal performance in these applications, it is imperative that the NPs be delivered effectively to the organs, tissues, and cells of interest. A rational approach to facilitating the delivery of NPs is to develop a detailed and comprehensive understanding in their fundamental interactions with the biological system (or nano-bio interactions). Rigorous nano-bio research can provide mechanistic insights for circumventing the bottlenecks associated with inefficient and nonspecific delivery of NPs, catalyzing the clinical translation of nanomedicines. Cationic liposomes and lipid NPs are conventional carriers of therapeutic cargoes into cells due to their high ability to penetrate the cell membrane, a barrier comprised by an anionic phospholipid bilayer. Yet, cationic NPs tend to cause cytotoxicity and immune responses that may hamper their clinical translation. Contrary to cationic NPs, non-cationic NPs (be they near-neutral or anionic in surface charge) generally exhibit higher biocompatibility but enter mammalian cells in much less pronounced amounts. Intriguingly, some types of non-cationic NPs exhibit high biocompatibility and cellular uptake properties, all attractive features for intracellular delivery. In this Account, we present our studies of the interactions of non-cationic bionanomaterials with cells (or nano-cell interactions). To start with, we introduce the use of near-neutral poly(ethylene glycol)-coated NPs for probing the roles of two rarely explored physicochemical parameters on cellular uptake, namely, extracellular compression and alkylation. We next present the nano-cell interactions of two representative types of anionic bionanomaterials that effectively enter mammalian cells and have found widespread applications in the past decade, including DNA-coated NPs and polydopamine (PDA)-coated NPs. In our cell-based studies, we dissect the route of intracellular trafficking, pathway proteins that dictate cellular uptake, and trafficking of NPs. We further touch on our recent quantitative analysis of the cellular-level distribution of NPs in various organs and tissues of diseased animal models. Our results offer important design rules of NPs for achieving effective intracellular delivery and may even guide us to explore nanomedicine applications that we did not conceive before, such as using DNA-coated NPs for targeting atherosclerotic plaques and PDA-coated plasmonic nanoworms for photothermal killing of cancer cells. We conclude with our perspectives in elucidating nano-bio interactions via a reductionist approach, calling for closer attention to the role of functional groups and more refined studies on the organelle-level distribution of NPs and the genetic basis of in vivo distribution of NPs.

Rutile nano-bio-interactions mediate dissimilar intracellular destiny in human skin cells

The use of nanoparticles (NPs) in the healthcare market is growing exponentially, due to their unique physicochemical properties. Titanium dioxide nanoparticles (TiO₂ NPs) are used in the formulation of sunscreens, due to their photoprotective capacity, but interactions of these particles with skin cells on the nanoscale are still unexplored. In the present study we aimed to determine whether the initial nano-biological interactions, namely the formation of a nano-bio-complex (other than the protein corona), can predict rutile internalization and intracellular trafficking in primary human fibroblasts and keratinocytes. Results showed no significant effect of NPs on fibroblast and keratinocyte viability, but cell proliferation was possibly compromised due to nano-bio-interactions. The bio-complex formation is dependent upon the chemistry of the biological media and NPs' physicochemical properties, facilitating NP internalization and triggering autophagy in both cell types. For the first time, we observed that the intracellular traffic of NPs is different when comparing the two skin cell models, and we detected NPs within multivesicular bodies (MVBs) of keratinocytes. These structures grant selected input of molecules involved in the biogenesis of exosomes, responsible for cell communication and, potentially, structural equilibrium in human tissues. Nanoparticle-mediated alterations of exosome quality, quantity and function can be another major source of nanotoxicity.

Understanding the Nano-bio Interfaces: Lipid-Coatings for Inorganic Nanoparticles as Promising Strategy for Biomedical Applications

Inorganic nanoparticles (NPs) exhibit relevant physical properties for application in biomedicine and specifically for both the diagnosis and therapy (i.e. theranostic) of severe pathologies, such as cancer. The inorganic NP core is often not stable in aqueous suspension and can induce cytotoxic effects. For this reason, over the years, several coating strategies were suggested to improve the NP stability in aqueous solutions as well as the NP biocompatibility. Among the various components which can be used for NP coatings, lipids, and in particular phospholipids emerged as versatile molecular building blocks for the production of NP coatings suitable for biomedical application. The recent synthetic efforts in NP lipid coatings allows today to introduce on the NP surface a large variety of lipid molecules eventually in mixture with amphiphilic or hydrophobic drugs or active molecules for cell targeting. In this review, the most relevant examples of NP lipid-coatings are presented and grouped in two main categories: supported lipid bilayers (SLB) and hybrid lipid bilayers (HLB). The discussed scientific cases take into account the most commonly used inorganic NP for biomedical applications in cancer therapy and diagnosis.

Toxicity of carbon-based nanomaterials: Reviewing recent reports in medical and biological systems

Application of nanomaterials in our daily life is increasing, day in day out and concerns have raised about their toxicity for human and other organisms. In this manner, carbon-based nanomaterials have been applied to different products due to their unique physicochemical, electrical, mechanical properties, and biological compatibility. But, there are several reports about the negative effects of these materials on biological systems and cellular compartments. This review article describes the various types of carbon-based nanomaterials and methods that use for determining these toxic effects that are reported recently in the papers. Then, extensively discussed the toxic effects of these materials on the human and other living organisms and also their toxicity routs including Neurotoxicity, Hepatotoxicity, Nephrotoxicity, Immunotoxicity, Cardiotoxicity, Genotoxicity and epigenetic toxicity, Dermatotoxicity, and Carcinogenicity.

Tailoring Nanomaterials for Targeting Tumor-Associated Macrophages

Advances in the field of nanotechnology together with an increase understanding of tumor immunology have paved the way for the development of more personalized cancer immuno-nanomedicines. Nanovehicles, due to their specific physicochemical properties, are emerging as key translational moieties in tackling tumor-promoting, M2-like tumor-associated macrophages (TAMs). Cancer immuno-nanomedicines target TAMs primarily by blocking M2-like TAM survival or affecting their signaling cascades, restricting macrophage recruitment to tumors and re-educating tumor-promoting M2-like TAMs to the tumoricidal, M1-like phenotype. Here, the TAM effector mechanisms and strategies for targeting TAMs are summarized, followed by a focus on the mechanistic considerations in the development of novel immuno-nanomedicines. Furthermore, imaging TAMs with nanoparticles so as to forecast a patient's clinical outcome, describing treatment options, and observing therapy responses is also discussed. At present, strategies that target TAMs are being investigated not only at the basic research level but also in early clinical trials. The significance of TAM-targeting biomaterials is highlighted, with the goal of facilitating future clinical translation.