Protein Corona Fingerprints of Liposomes: New Opportunities for Targeted Drug Delivery and Early Detection in Pancreatic Cancer

Review of recent preclinical and clinical research on ligand-targeted liposomes as delivery systems in triple negative breast cancer therapy

Triple-negative breast Cancer (TNBC) is one of the deadliest types, making up about 20% of all breast cancers. Chemotherapy is the traditional manner of progressed TNBC treatment; however, it has a short-term result with a high reversibility pace. The lack of targeted treatment limited and person-dependent treatment options for those suffering from TNBC cautions to be the worst type of cancer among breast cancer patients. Consequently, appropriate treatment for this disease is considered a major clinical challenge. Therefore, various treatment methods have been developed to treat TNBC, among which chemotherapy is the most common and well-known approach recently studied. Although effective methods are chemotherapies, they are often accompanied by critical limitations, especially the lack of specific functionality. These methods lead to systematic toxicity and, ultimately, the expansion of multidrug-resistant (MDR) cancer cells. Therefore, finding novel and efficient techniques to enhance the targeting of TNBC treatment is an essential requirement. Liposomes have demonstrated that they are an effective method for drug delivery; however, among a large number of liposome-based drug delivery systems annually developed, a small number have just received authorization for clinical application. The new approaches to using liposomes target their structure with various ligands to increase therapeutic efficiency and diminish undesired side effects on various body tissues. The current study describes the most recent strategies and research associated with functionalizing the liposomes' structure with different ligands as targeted drug carriers in treating TNBCs in preclinical and clinical stages.

Personalized biocorona as disease biomarker: The challenges and opportunities

It is well known that when nanoparticles interact with biological fluids, a layer of proteins and biological components forms on them. This layer may alter the biological fate and efficiency of the nanomaterial. Recent studies have shown that illness states have a major impact on the structure of the biocorona, sometimes referred to as the "personalized protein corona." Physiological factors like illness, which impact the proteome and metabolome pattern and result in conformational changes in proteins, give rise to this structure of discrimination in biocorona decoration. Improving the efficiency of precise platforms for developing new molecular biomarkers for accurate illness diagnosis is vitally necessary. The biocorona pattern's discrimination may be a diagnostic tool for designing biosensors. As a result, in this review, we summarize the most current studies on the relationship between physiological conditions and the variety of biocorona patterns that influence the biological responses of nanosystems. The biocorona pattern's flexibility may provide new research directions and be utilized to create nanoparticle-based therapeutic and diagnostic products suited to certain physiological situations.

Biofluid specific protein coronas affect lipid nanoparticle behavior in vitro

Lipid nanoparticles (LNPs) have successfully entered the clinic for the delivery of mRNA- and siRNA-based therapeutics, most recently as vaccines for COVID-19. Nevertheless, there is a lack of understanding regarding their in vivo behavior, in particular cell targeting. Part of this LNP tropism is based on the adherence of endogenous protein to the particle surface. This protein forms a so-called corona that can change, amongst other things, the circulation time, biodistribution and cellular uptake of these particles. The formation of this protein corona, in turn, is dependent on the nanoparticle properties (e.g., size, charge, surface chemistry and hydrophobicity) as well as the biological environment from which it is derived. With the potential of gene therapy to target virtually any disease, administration sites other than intravenous route are considered, resulting in tissue specific protein coronas. For neurological diseases, intracranial administration of LNPs results in a cerebral spinal fluid derived protein corona, possibly changing the properties of the lipid nanoparticle compared to intravenous administration. Here, the differences between plasma and CSF derived protein coronas on a clinically relevant LNP formulation were studied in vitro. Protein analysis showed that LNPs incubated in human CSF (C-LNPs) developed a protein corona composition that differed from that of LNPs incubated in plasma (P-LNPs). Lipoproteins as a whole, but in particular apolipoprotein E, represented a higher percentage of the total protein corona on C-LNPs than on P-LNPs. This resulted in improved cellular uptake of C-LNPs compared to P-LNPs, regardless of cell origin. Importantly, the higher LNP uptake did not directly translate into more efficient cargo delivery, underlining that further assessment of such mechanisms is necessary. These findings show that biofluid specific protein coronas alter LNP functionality, suggesting that the site of administration could affect LNP efficacy in vivo and needs to be considered during the development of the formulation.

A Review for Uncovering the "Protein-Nanoparticle Alliance": Implications of the Protein Corona for Biomedical Applications

Understanding both the physicochemical and biological interactions of nanoparticles is mandatory for the biomedical application of nanomaterials. By binding proteins, nanoparticles acquire new surface identities in biological fluids, the protein corona. Various studies have revealed the dynamic structure and nano-bio interactions of the protein corona. The binding of proteins not only imparts new surface identities to nanoparticles in biological fluids but also significantly influences their bioactivity, stability, and targeting specificity. Interestingly, recent endeavors have been undertaken to harness the potential of the protein corona instead of evading its presence. Exploitation of this 'protein-nanoparticle alliance' has significant potential to change the field of nanomedicine. Here, we present a thorough examination of the latest research on protein corona, encompassing its formation, dynamics, recent developments, and diverse bioapplications. Furthermore, we also aim to explore the interactions at the nano-bio interface, paving the way for innovative strategies to advance the application potential of the protein corona. By addressing challenges and promises in controlling protein corona formation, this review provides insights into the evolving landscape of the 'protein-nanoparticle alliance' and highlights emerging.

Impact of Lipid Composition on Vesicle Protein Adsorption: A BSA Case Study

Investigating the interaction between liposomes and proteins is of paramount importance in the development of liposomal formulations with real potential for bench-to-bedside transfer. Upon entering the body, proteins are immediately adsorbed on the liposomal surface, changing the nanovehicles' biological identity, which has a significant impact on their biodistribution and pharmacokinetics and ultimately on their therapeutic effect. Albumin is the most abundant plasma protein and thus usually adsorbs immediately on the liposomal surface. We herein report a comprehensive investigation on the adsorption of model protein bovine serum albumin (BSA) onto liposomal vesicles containing the zwitterionic lipid 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC), in combination with either cholesterol (CHOL) or the cationic lipid 1,2-dioleoyl-3-trimethylammoniumpropane (DOTAP). While many studies regarding protein adsorption on the surface of liposomes with different compositions have been performed, to the best of our knowledge, the differential responses of CHOL and DOTAP upon albumin adsorption on vesicles have not yet been investigated. UV-vis spectroscopy and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) revealed a strong influence of the phospholipid membrane composition on protein adsorption. Hence, it was found that DOTAP-containing vesicles adsorb proteins more robustly but also aggregate in the presence of BSA, as confirmed by DLS and TEM. Separation of liposome-protein complexes from unadsorbed proteins performed by means of centrifugation and size exclusion chromatography (SEC) was also investigated. Our results show that neither method can be regarded as a golden experimental setup to study the protein corona of liposomes. Yet, SEC proved to be more successful in the separation of unbound proteins, although the amount of lipid loss upon liposome elution was higher than expected. In addition, coarse-grained molecular dynamics simulations were employed to ascertain key membrane parameters, such as the membrane thickness and area per lipid. Overall, this study highlights the importance of surface charge and membrane fluidity in influencing the extent of protein adsorption. We hope that our investigation will be a valuable contribution to better understanding protein-vesicle interactions for improved nanocarrier design.

Blood-Based Multiomics-Guided Detection of a Precancerous Pancreatic Tumor

Over a decade ago, longitudinal multiomics analysis was pioneered for early disease detection and individually tailored precision health interventions. However, high sample processing costs, expansive multiomics measurements along with complex data analysis have made this approach to precision/personalized medicine impractical. Here we describe in a case report, a more practical approach that uses fewer measurements, annual sampling, and faster decision making. We also show how this approach offers promise to detect an exceedingly rare and potentially fatal condition before it fully manifests. Specifically, we describe in the present case report how longitudinal multiomics monitoring (LMOM) helped detect a precancerous pancreatic tumor and led to a successful surgical intervention. The patient, enrolled in an annual blood-based LMOM since 2018, had dramatic changes in the June 2021 and 2022 annual metabolomics and proteomics results that prompted further clinical diagnostic testing for pancreatic cancer. Using abdominal magnetic resonance imaging, a 2.6 cm lesion in the tail of the patient's pancreas was detected. The tumor fluid from an aspiration biopsy had 10,000 times that of normal carcinoembryonic antigen levels. After the tumor was surgically resected, histopathological findings confirmed it was a precancerous pancreatic tumor. Postoperative omics testing indicated that most metabolite and protein levels returned to patient's 2018 levels. This case report illustrates the potentials of blood LMOM for precision/personalized medicine, and new ways of thinking medical innovation for a potentially life-saving early diagnosis of pancreatic cancer. Blood LMOM warrants future programmatic translational research with the goals of precision medicine, and individually tailored cancer diagnoses and treatments.

Controlling the protein corona of polymeric nanocapsules: effect of polymer shell on protein adsorption

Understanding the interactions between nanocarriers and plasma proteins is essential for controlling their biological fate. Based on the reported potential of polymeric nanocapsules (NCs) for the targeted delivery of oncological drugs, the main objective of this work has been to investigate how the surface chemical composition influences their protein corona fingerprint. Thus, we developed six NC prototypes with different polymer shells and physicochemical properties and quantified the amount of protein adsorbed upon incubation in human plasma. Using sequential window acquisition of all theoretical mass spectra (SWATH-MS) and following the Minimum Information about Nanomaterial Biocorona Experiments (MINBE) guidelines, we identified different protein corona patterns. As expected, the presence of polyethylene glycol (PEG) in the polymer shell reduced the protein corona, particularly the adsorption of immunoglobulins. However, by comparing the different prototypes, we concluded that the protein adsorption pattern was not exclusively driven by PEG. In fact, a highly PEGylated prototype exhibited intense apolipoprotein IV adsorption. On the other hand, we also observed that polymeric NCs containing 1,2-dioleoyl-3-trimethylammonium propane (DOTAP) exhibited high adsorption of vitronectin, a protein that is known for enhancing the uptake of nanosystems by lung epithelium and several cancer cells. Overall, the gathered information allowed us to identify promising polymeric NCs with an expected prolonged circulation time, enhanced tumor targeting, liver accumulation, and preferential uptake by the immune system. In this sense, the analyses of the protein corona performed along this work will hopefully contribute to advancing a new generation of rationally designed nanometric drug delivery systems.

Sodium alginate and chitosan co-modified fucoxanthin liposomes: preparation, bioaccessibility and antioxidant activity

To improve the stability of fucoxanthin, fucoxanthin liposomes (L) were prepared by the thin-film ultrasound method, and fucoxanthin liposomes were modified with sodium alginate and chitosan by an electrostatic deposition method. The release characteristics of fucoxanthin in different types of liposomes with in vitro gastrointestinal simulation were studied. Under the optimum conditions, the results showed that the encapsulation efficiency of prepared liposomes could reach 88.56 ± 1.40% (m/m), with an average particle size of 295.27 ± 7.28 nm, a Zeta potential of -21.53 ± 2.00 mV, a polydispersity index (PDI) of 0.323 ± 0.007 and a loading capacity of 33.3 ± 0.03% (m/m). Compared with L and chitosan modified fucoxanthin liposomes (CH), sodium alginate and chitosan modified fucoxanthin liposomes (SA-CH) exhibited higher storage stability, in vitro bioaccessibility and antioxidant activity after gastrointestinal digestion. Sodium alginate and chitosan co-modified liposomes can be developed as formulations for encapsulation and delivery of functional ingredients, providing a theoretical basis for developing new fucoxanthin series products.

Coupling magnetic levitation of graphene oxide–protein complexes with blood levels of glucose for early detection of pancreatic adenocarcinoma

Introduction

Pancreatic adenocarcinoma (PDAC) has a poor prognosis since often diagnosed too late. Dyslipidemia and hyperglycemia are considered risk factors, but the presence of the tumor itself can determine the onset of these disorders. Therefore, it is not easy to predict which subjects with diabetes or dyslipidemia will develop or have already developed PDAC. Over the past decade, tests based on the use of nanotechnology, alone or coupled with common laboratory tests (e.g., hemoglobin levels), have proven useful in aiding the diagnosis of PDAC. Tests based on magnetic levitation (MagLev) have demonstrated high diagnostic accuracy in compliance with the REASSURED criteria. Here, we aimed to assess the ability of the MagLev test in detecting PDAC when coupled with the blood levels of glycemia, cholesterol, and triglycerides.

Methods

Blood samples from 24 PDAC patients and 22 healthy controls were collected. Human plasma was let to interact with graphene oxide (GO) nanosheets and the emerging coronated systems were put in the MagLev device. Outcomes from Maglev experiments were coupled to glycemia, cholesterol, and triglycerides levels. Linear discriminant analysis (LDA) was carried out to evaluate the classification ability of the test in terms of specificity, sensitivity, and global accuracy. Statistical analysis was performed with Matlab (MathWorks, Natick, MA, USA, Version R2022a) software.

Results

The positions of the levitating bands were measured at the starting point (i.e., as soon as the cuvette containing the sample was subjected to the magnetic field). Significant variations in the starting position of levitating nanosystems in controls and PDACs were detected. The combination of the MagLev outcomes with the blood glycemic levels returned the best value of global accuracy (91%) if compared to the coupling with those of cholesterol and triglycerides (global accuracy of ~ 77% and 84%, respectively).

Conclusion

If confirmed by further studies on larger cohorts, a multiplexed Maglev-based nanotechnology-enabled blood test could be employed as a screening tool for PDAC in populations with hyperglycemia.

Challenges and Opportunities Associated With Drug Delivery for the Treatment of Solid Tumors

In this review, we discuss the effectiveness of drug delivery system based on metal nanoparticles, and also, describe the problems associated with their delivery to tumor cells. Throughout recent years, more reports have appeared in the literature that demonstrate promising results for the treatment of various types of cancer using metal-based nanoparticles. Due to their unique physical and chemical properties, metal nanoparticles are effectively being used for the delivery of drug to the tumor cells, for cancer diagnosis and treatment. They can also be synthesized allowing the control of size and shape. However, the effectiveness of the metal nanoparticles for cancer treatment largely depends on their stability, biocompatibility, and ability to selectively affect tumor cells after their systemic or local administration. Another major problem associated with metal nanoparticles is their ability to overcome tumor tissue barriers such as atypical blood vessel structure, dense and rigid extracellular matrix, and high pressure of tumor interstitial fluid. The review also describes the design of tumor drug delivery systems that are based on metal nanoparticles. The mechanism of action of metal nanoparticles on cancer cells is also discussed. Considering the therapeutic safety and toxicity of metal nanoparticles, the prospects for their use for future clinical applications are being currently reviewed.

Protein Corona of Anionic Fluid-Phase Liposomes Compromises Their Integrity Rather than Uptake by Cells

Despite the undisputable role of the protein corona in the biointeractions of liposome drug carriers, the field suffers from a lack of knowledge regarding the patterns of protein deposition on lipid surfaces with different compositions. Here, we investigated the protein coronas formed on liposomes of basic compositions containing combinations of egg phosphatidylcholine (PC), palmitoyloleoyl phosphatidylglycerol (POPG), and cholesterol. Liposome-protein complexes isolated by size-exclusion chromatography were delipidated and analyzed using label-free LC-MS/MS. The addition of the anionic lipid and cholesterol both affected the relative protein abundances (and not the total bound proteins) in the coronas. Highly anionic liposomes, namely those containing 40% POPG, carried corona enriched with cationic proteins (apolipoprotein C1, beta-2-glycoprotein 1, and cathelicidins) and were the least stable in the calcein release assay. Cholesterol improved the liposome stability in the plasma. However, the differences in the corona compositions had little effect on the liposome uptake by endothelial (EA.hy926) and phagocytic cells in the culture (U937) or ex vivo (blood-derived monocytes and neutrophils). The findings emphasize that the effect of protein corona on the performance of the liposomes as drug carriers occurs through compromising particle stability rather than interfering with cellular uptake.

Current advances in the use of exosomes, liposomes, and bioengineered hybrid nanovesicles in cancer detection and therapy

Three major approaches of cancer therapy can be enunciated as delivery of biotherapeutics, tumor image analysis, and immunotherapy. Liposomes, artificial fat bubbles, are long known for their capacity to encapsulate a diverse range of bioactive molecules and release the payload in a sustained, stimuli-responsive manner. They have already been widely explored as a delivery vehicle for therapeutic drugs as well as imaging agents. They are also extensively being used in cancer immunotherapy. On the other hand, exosomes are naturally occurring nanosized extracellular vesicles that serve an important role in cell-cell communication. Importantly, the exosomes also have proven their capability to carry an array of active pharmaceuticals and diagnostic molecules to the tumor cells. Exosomes, being enriched with tumor antigens, have numerous immunomodulatory effects. Much to our intrigue, in recent times, efforts have been directed toward developing smart, bioengineered, exosome-liposome hybrid nanovesicles, which are augmented by the benefits of both vesicular systems. This review attempts to summarize the contemporary developments in the use of exosome and liposome toward cancer diagnosis, therapy, as a vehicle for drug delivery, diagnostic carrier for tumor imaging, and cancer immunotherapy. We shall also briefly reflect upon the recent advancements of the exosome-liposome hybrids in cancer therapy. Finally, we put forward future directions for the use of exosome/liposome and/or hybrid nanocarriers for accurate diagnosis and personalized therapies for cancers.

Engineering nano-drug biointerface to overcome biological barriers toward precision drug delivery

The rapid advancement of nanomedicine and nanoparticle (NP) materials presents novel solutions potentially capable of revolutionizing health care by improving efficacy, bioavailability, drug targeting, and safety. NPs are intriguing when considering medical applications because of their essential and unique qualities, including a significantly higher surface to mass ratio, quantum properties, and the potential to adsorb and transport drugs and other compounds. However, NPs must overcome or navigate several biological barriers of the human body to successfully deliver drugs at precise locations. Engineering the drug carrier biointerface can help overcome the main biological barriers and optimize the drug delivery in a more personalized manner. This review discusses the significant heterogeneous biological delivery barriers and how biointerface engineering can promote drug carriers to prevail over hurdles and navigate in a more personalized manner, thus ushering in the era of Precision Medicine. We also summarize the nanomedicines' current advantages and disadvantages in drug administration, from natural/synthetic sources to clinical applications. Additionally, we explore the innovative NP designs used in both non-personalized and customized applications as well as how they can attain a precise therapeutic strategy.

Artificial engineering of the protein corona at bio-nano interfaces for improved cancer-targeted nanotherapy

Nanoparticles (NPs) have been used in numerous applications as anticancer, antibacterial and antioxidant agents. Artificial engineering of protein interactions with NPs in biological systems is crucial to develop potential NPs for drug delivery and cancer nanotherapy. The protein corona (PC) on the NP surface, displays an interface between biomacromolecules and NPs, governing their pharmacokinetics and pharmacodynamics. Upon interaction of proteins with the NPs, their surface features are modified and they can easily be removed from the circulation by the mononuclear phagocytic system (MPS). PC properties heavily depend on the biological microenvironment and NP physicochemical parameters. Based on this context, we have surveyed different approaches that have been used for artificial engineering of the PC composition on NP surfaces. We discussed the effects of NP size, shape, surface modifications (PEGylation, self-peptide, other polymers), and protein pre-coating on the PC properties. Additionally, other factors including protein source and structure, intravenous injection and the subsequent shear flow, plasma protein gradients, temperature and local heat transfer, and washing media were considered in the context of their effects on the PC properties and overall target cellular effects. Moreover, the effects of NP-PC complexes on cancer cells based on cellular interactions, organization of intracellular PC (IPC), targeted drug delivery (TDD) and regulation of burst drug release profile of nanoplatforms, enhanced biocompatibility, and clinical applications were discussed followed by challenges and future perspective of the field. In conclusion, this paper can provide useful information to manipulate PC properties on the NP surface, thus trying to provide a literature survey to shorten their shipping from preclinical to clinical trials and to lay the basis for a personalized PC.

Liposomes: structure, composition, types, and clinical applications

Liposomes are now considered the most commonly used nanocarriers for various potentially active hydrophobic and hydrophilic molecules due to their high biocompatibility, biodegradability, and low immunogenicity. Liposomes also proved to enhance drug solubility and controlled distribution, as well as their capacity for surface modifications for targeted, prolonged, and sustained release. Based on the composition, liposomes can be considered to have evolved from conventional, long-circulating, targeted, and immune-liposomes to stimuli-responsive and actively targeted liposomes. Many liposomal-based drug delivery systems are currently clinically approved to treat several diseases, such as cancer, fungal and viral infections; more liposomes have reached advanced phases in clinical trials. This review describes liposomes structure, composition, preparation methods, and clinical applications.

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.

The ancillary effects of nanoparticles and their implications for nanomedicine

Nanoparticles are often engineered as a scaffolding system to combine targeting, imaging and/or therapeutic moieties into a unitary agent. However, mostly overlooked, the nanomaterial itself interacts with biological systems exclusive of application-specific particle functionalization. This nanoparticle biointerface has been found to elicit specific biological effects, which we term 'ancillary effects'. In this Review, we describe the current state of knowledge of nanobiology gleaned from existing studies of ancillary effects with the objectives to describe the potential of nanoparticles to modulate biological effects independently of any engineered function; evaluate how these effects might be relevant for nanomedicine design and functional considerations, particularly how they might be useful to inform clinical decision-making; identify potential clinical harm that arises from adverse nanoparticle interactions with biology; and, finally, highlight the current lack of knowledge in this area as both a barrier and an incentive to the further development of nanomedicine.

Spotlight on the protein corona of liposomes

Although an established drug delivery platform, liposomes have not fulfilled their true potential. In the body, interactions of liposomes are mediated by the layer of plasma proteins adsorbed on the surface, the protein corona. The review aims to collect the data of the last decade on liposome protein corona, tracing the path from interactions of individual proteins to the effects mediated by the protein corona in vivo. It offers a classification of the approaches to exploitation of the protein corona-rather than elimination thereof-based on the bilayer composition-corona composition-molecular interactions-biological performance framework. The multitude of factors that affect each level of this relationship urge to the widest implementation of bioinformatics tools to predict the most effective liposome compositions relying on the data on protein corona. Supplementing the picture with new pieces of accurately reported experimental data will contribute to the accuracy and efficiency of the predictions. STATEMENT OF SIGNIFICANCE: The review focuses on liposomes as an established nanomedicine platform and analyzes the available data on how the protein corona formed on liposome surface in biological fluids affects performance of the liposomes. The review offers a rigorous account of existing literature and critical analysis of methodology currently applied to the assessment of liposome-plasma protein interactions. It introduces a classification of the approaches to exploitation of the protein corona and tailoring liposome carriers to advance the field of nanoparticulate drug delivery systems for the benefit of patients.

An "eat me" combinatory nano-formulation for systemic immunotherapy of solid tumors

Rational: Tumor immunogenic cell death (ICD), induced by certain chemotherapeutic drugs such as doxorubicin (Dox), is a form of apoptosis potentiating a protective immune response. One of the hallmarks of ICD is the translocation of calreticulin to the cell surface acting as an 'eat me' signal. This manuscript describes the development of a stable nucleic acid-lipid particles (SNALPs) formulation for the simultaneous delivery of ICD inducing drug (Dox) with small interfering RNA (siRNA) knocking down CD47 (siCD47), the dominant 'don't eat me' marker, for synergistic enhancement of ICD. Methods: SNALPs loaded with Dox or siCD47 either mono or combinatory platforms were prepared by ethanol injection method. The proposed systems were characterized for particle size, surface charge, entrapment efficiency and in vitro drug release. The ability of the SNALPs to preserve the siRNA integrity in presence of serum and RNAse were assessed over 48 h. The in vitro cellular uptake and gene silencing of the prepared SNALPs was assessed in CT26 cells. The immunological responses of the SNALPs were defined in vitro in terms of surface calreticulin expression and macrophage-mediated phagocytosis induction. In vivo therapeutic studies were performed in CT26 bearing mice where the therapeutic outcomes were expressed as tumor volume, expression of CD4 and CD8 as well as in vivo silencing. Results: The optimized SNALPs had a particle size 122 ±6 nm and an entrapment efficiency > 65% for both siRNA and Dox with improved serum stability. SNALPs were able to improve siRNA and Dox uptake in CT26 cells with enhanced cytotoxicity. siCD47 SNALPs were able to knockdown CD47 by approximately 70% with no interference from the presence of Dox. The siCD47 and Dox combination SNALPs were able to induce surface calreticulin expression leading to a synergistic effect on macrophage-mediated phagocytosis of treated cells. In a tumor challenge model, 50% of mice receiving siCD47 and Dox containing SNALPs were able to clear the tumor, while the remaining animals showed significantly lower tumor burden as compared to either monotreatment. Conclusion: Therefore, the combination of siCD47 and Dox in a particulate system showed potent anti-tumor activity which merits further investigation in future clinical studies.

Interplay between nanomedicine and protein corona

Nanomedicine is recognized as a promising agent for diverse biomedical applications; however, its safety and efficiency in clinical practice remains to be enhanced. A priority issue is the protein corona (PC), which imparts unique biological identities to prototype and determines the actual biological functions in biological fluids. Decades of work has already illuminated abundant considerations that influence the composition of the protein corona. Thereinto, the physical assets of nanomedicines (e.g., size and shape, surface properties, nanomaterials) and the biological environment collectively play fundamental roles in shaping the PC, including the types and quantities of plasma proteins. The properties of nanomedicines are dependent on certain factors. This review aims to explore the applications of nanomedicines by regulating their interplay with PC.

Protein corona profile of graphene oxide allows detection of glioblastoma multiforme using a simple one-dimensional gel electrophoresis technique: a proof-of-concept study

Glioblastoma multiforme (GBM) is the most aggressive form of gliomas. The development of supplementary approaches for glioblastoma diagnosis, limited to imaging techniques and tissue biopsies so far, is a necessity of clinical relevance. In this context, nanotechnology might afford tools to enable early diagnosis. Upon exposure to biological media, nanoparticles are coated with a layer of proteins, the protein corona (PC), whose composition is individual and personalized. Here we show that the PC of graphene oxide nanosheets has a capacity to detect GBM using a simple one-dimensional gel electrophoresis technique. In a range of molecular weights between 100 and 120 kDa, the personalized PC from GBM patients is completely discernible from that of healthy donors and that of cancer patients affected by pancreatic adenocarcinoma and colorectal cancer. Using tandem mass spectrometry, we found that inter-alpha-trypsin inhibitor (ITI) heavy chain H4 is enriched in the PC of all tested individuals but not in the GBM patients. Overall, if confirmed on a larger cohort series, this approach could be advantageous at the first level of investigation to decide whether to carry out more invasive analyses and/or to follow up patients after surgery and/or pharmacological treatment.

Nano-bio interface between human plasma and niosomes with different formulations indicates protein corona patterns for nanoparticle cell targeting and uptake

Unraveling the proteins interacting with nanoparticles (NPs) in biological fluids, such as blood, is pivotal to rationally design NPs for drug delivery. The protein corona (PrC), formed on the NP surface, represents an interface between biological components and NPs, dictating their pharmacokinetics and biodistribution. PrC composition depends on biological environments around NPs and on their intrinsic physicochemical properties. We generated different formulations of non-ionic surfactant/non-phospholipid vesicles, called niosomes (NIOs), using polysorbates which are biologically safe, cheap, non-toxic and scarcely immunogenic. PrC composition and relative protein abundance for all designed NIOs were evaluated ex vivo in human plasma (HP) by quantitative label-free proteomics. We studied the correlation of the relative protein abundance in the corona with cellular uptake of the PrC-NIOs in healthy and cancer human cell lines. Our results highlight the effects of polysorbates on nano-bio interactions to identify a protein pattern most properly aimed to drive the NIO targeting in vivo, and assess the best conditions of PrC-NIO NP uptake into the cells. This study dissected the biological identity in HP of polysorbate-NIOs, thus contributing to shorten their passage from preclinical to clinical studies and to lay the foundations for a personalized PrC.

Biocompatibility of nanomaterials and their immunological properties

Nanomaterials (NMs) have revolutionized multiple aspects of medicine by enabling novel sensing, diagnostic, and therapeutic approaches. Advancements in processing and fabrication have also allowed significant expansion in the applications of the major classes of NMs based on polymer, metal/metal oxide, carbon, liposome, or multi-scale macro-nano bulk materials. Concomitantly, concerns regarding the nanotoxicity and overall biocompatibility of NMs have been raised. These involve putative negative effects on both patients and those subjected to occupational exposure during manufacturing. In this review, we describe the current state of testing of NMs including those that are in clinical use, in clinical trials, or under development. We also discuss the cellular and molecular interactions that dictate their toxicity and biocompatibility. Specifically, we focus on the reciprocal interactions between NMs and host proteins, lipids, and sugars and how these induce responses in immune and other cell types leading to topical and/or systemic effects.

Emerging Biomolecular Testing to Assess the Risk of Mortality from COVID-19 Infection

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2 and COVID-19) has produced an unprecedented global pandemic. Though the death rate from COVID-19 infection is ∼2%, many infected people recover at home. Among patients for whom COVID-19 is deadly are those with pre-existing comorbidities. Therefore, identification of populations at highest risk of COVID-19 mortality could significantly improve the capacity of healthcare providers to take early action and minimize the possibility of overwhelming care centers, which in turn would save many lives. Although several approaches have been used/developed (or are being developed/suggested) to diagnose COVID-19 infection, no approach is available/proposed for fast diagnosis of COVID-19 infections likely to be fatal. The central aim of this short perspective is to suggest a few possible nanobased technologies (i.e., protein corona sensor array and magnetic levitation) that could discriminate COVID-19-infected people while still in the early stages of infection who are at high risk of death. Such discrimination technologies would not only be useful in protecting health care centers from becoming overwhelmed but would also provide a powerful tool to better control possible future pandemics with a less social and economic burden.

Biological effects of formation of protein corona onto nanoparticles

Administration of nanomaterials based medicinal and drug carrier systems into systemic circulation brings about interaction of blood components e.g. albumin and globulin proteins with these nanosystems. These blood or serum proteins either get loosely attached over these nanocarriers and form soft protein corona or are tightly adsorbed over nanoparticles and hard protein corona formation occurs. Formation of protein corona has significant implications over a wide array of physicochemical and medicinal attributes. Almost all pharmacological, toxicological and carrier characteristics of nanoparticles get prominently touched by the protein corona formation. It is this interaction of nanoparticle protein corona that decides and influences fate of nanomaterials-based systems. In this article, authors reviewed several diverse aspects of protein corona formation and its implications on various possible outcomes in vivo and in vitro. A brief description regarding formation and types of protein corona has been included along with mechanisms and pharmacokinetic, pharmacological behavior and toxicological profiles of nanoparticles has been described. Finally, significance of protein corona in context of its in vivo and in vitro behavior, involvement of biomolecules at nanoparticle plasma interface and other interfaces and effects of protein corona on biocompatibility characteristics have also been touched upon.

Disentangling Biomolecular Corona Interactions With Cell Receptors and Implications for Targeting of Nanomedicines

Nanoparticles are promising tools for nanomedicine in a wide array of therapeutic and diagnostic applications. Yet, despite the advances in the biomedical applications of nanomaterials, relatively few nanomedicines made it to the clinics. The formation of the biomolecular corona on the surface of nanoparticles has been known as one of the challenges toward successful targeting of nanomedicines. This adsorbed protein layer can mask targeting moieties and creates a new biological identity that critically affects the subsequent biological interactions of nanomedicines with cells. Extensive studies have been directed toward understanding the characteristics of this layer of biomolecules and its implications for nanomedicine outcomes at cell and organism levels, yet several aspects are still poorly understood. One aspect that still requires further insights is how the biomolecular corona interacts with and is “read” by the cellular machinery. Within this context, this review is focused on the current understanding of the interactions of the biomolecular corona with cell receptors. First, we address the importance and the role of receptors in the uptake of nanoparticles. Second, we discuss the recent advances and techniques in characterizing and identifying biomolecular corona-receptor interactions. Additionally, we present how we can exploit the knowledge of corona-cell receptor interactions to discover novel receptors for targeting of nanocarriers. Finally, we conclude this review with an outlook on possible future perspectives in the field. A better understanding of the first interactions of nanomaterials with cells, and -in particular -the receptors interacting with the biomolecular corona and involved in nanoparticle uptake, will help for the successful design of nanomedicines for targeted delivery.

Molecular Therapeutics of Pancreatic Ductal Adenocarcinoma: Targeted Pathways and the Role of Cancer Stem Cells

Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal cancers in humans due to late detection and highly metastatic characteristics. PDAC cells vary in their tumorigenic capabilities with the presence of a subset of PDAC cells known as pancreatic cancer stem cells (CSCs), which are more resistant to currently used therapeutics. Here, we describe the role of CSCs and tumour stroma in developing therapeutic strategies for PDAC and suggest that developmental plasticity could be considered a hallmark of cancers. We provide an overview of the molecular targets in PDAC treatments, including targeted therapies of cellular processes such as proliferation, evasion of growth suppressors, activating metastasis, and metabolic effects. Since PDAC is an inflammation-driven cancer, we also revisit therapeutic strategies targeting inflammation and immunotherapy. Lastly, we suggest that targeting epigenetic mechanisms opens therapeutic routes for heterogeneous cancer cell populations, including CSCs.

Preparation, Biosafety, and Cytotoxicity Studies of a Newly Tumor-Microenvironment-Responsive Biodegradable Mesoporous Silica Nanosystem Based on Multimodal and Synergistic Treatment

Patients with triple negative breast cancer (TNBC) often suffer relapse, and clinical improvements offered by radiotherapy and chemotherapy are modest. Although targeted therapy and immunotherapy have been a topic of significant research in recent years, scientific developments have not yet translated to significant improvements for patients with TNBC. In view of these current clinical treatment shortcomings, we designed a silica nanosystem (SNS) with Nano-Ag as the core and a complex of MnO₂ and doxorubicin (Dox) as the surrounding mesoporous silica shell. This system was coated with anti-PD-L1 to target the PD-L1 receptor, which is highly expressed on the surface of tumor cells. MnO₂ itself has been shown to act as chemodynamic therapy (CDT), and Dox is cytotoxic. Thus, the full SNS system presents a multimodal, potentially synergistic strategy for the treatment of TNBC. Given potential interest in the clinical translation of SNS, the biological safety and antitumor activity of SNS were evaluated in a series of studies that included physicochemical characterization, particle stability, blood compatibility, and cytotoxicity. We found that the particle size and zeta potential of SNS were 94.6 nm and -22.1 mV, respectively. Ultraviolet spectrum analysis showed that Nano-Ag, Dox, and MnO₂ were successfully loaded into SNS, and the drug loading ratio of Dox was about 10.2%. Stability studies found that the particle size of SNS did not change in different solutions. Hemolysis tests showed that SNS, at levels far exceeding the anticipated physiologic concentrations, did not induce red blood cell lysis. Further in vitro and in vivo experiments found that SNS did not activate platelets or cause coagulopathy and had no significant effects on the total number of blood cells or hepatorenal function. Cytotoxicity experiments suggested that SNS significantly inhibited the growth of tumor cells by damaging cell membranes, increasing intracellular ROS levels, inhibiting the release of TGF-β1 cytokines by macrophages, and inhibiting intracellular protein synthesis. In general, SNS appeared to have favorable biosafety and antitumor effects and may represent an attractive new therapeutic approach for the treatment of TNBC.

Mastering the Tools: Natural versus Artificial Vesicles in Nanomedicine

Naturally occurring extracellular vesicles and artificially made vesicles represent important tools in nanomedicine for the efficient delivery of biomolecules and drugs. Since its first appearance in the literature 50 years ago, the research on vesicles is progressing at a fast pace, with the main goal of developing carriers able to protect cargoes from degradation, as well as to deliver them in a time- and space-controlled fashion. While natural occurring vesicles have the advantage of being fully compatible with their host, artificial vesicles can be easily synthetized and functionalized according to the target to reach. Research is striving to merge the advantages of natural and artificial vesicles, in order to provide a new generation of highly performing vesicles, which would improve the therapeutic index of transported molecules. This progress report summarizes current manufacturing techniques used to produce both natural and artificial vesicles, exploring the promises and pitfalls of the different production processes. Finally, pros and cons of natural versus artificial vesicles are discussed and compared, with special regard toward the current applications of both kinds of vesicles in the healthcare field.

The Biomolecular Corona of Lipid Nanoparticles for Gene Therapy

Gene therapy holds great potential for treating almost any disease by gene silencing, protein expression, or gene correction. To efficiently deliver the nucleic acid payload to its target tissue, the genetic material needs to be combined with a delivery platform. Lipid nanoparticles (LNPs) have proven to be excellent delivery vectors for gene therapy and are increasingly entering into routine clinical practice. Over the past two decades, the optimization of LNP formulations for nucleic acid delivery has led to a well-established body of knowledge culminating in the first-ever RNA interference therapeutic using LNP technology, i.e., Onpattro, and many more in clinical development to deliver various nucleic acid payloads. Screening a lipid library in vivo for optimal gene silencing potency in hepatocytes resulted in the identification of the Onpattro formulation. Subsequent studies discovered that the key to Onpattro's liver tropism is its ability to form a specific "biomolecular corona". In fact, apolipoprotein E (ApoE), among other proteins, adsorbed to the LNP surface enables specific hepatocyte targeting. This proof-of-principle example demonstrates the use of the biomolecular corona for targeting specific receptors and cells, thereby opening up the road to rationally designing LNPs. To date, however, only a few studies have explored in detail the corona of LNPs, and how to efficiently modulate the corona remains poorly understood. In this review, we summarize recent discoveries about the biomolecular corona, expanding the knowledge gained with other nanoparticles to LNPs for nucleic acid delivery. In particular, we address how particle stability, biodistribution, and targeting of LNPs can be influenced by the biological environment. Onpattro is used as a case study to describe both the successful development of an LNP formulation for gene therapy and the key influence of the biological environment. Moreover, we outline the techniques available to isolate and analyze the corona of LNPs, and we highlight their advantages and drawbacks. Finally, we discuss possible implications of the biomolecular corona for LNP delivery and we examine the potential of exploiting the corona as a targeting strategy beyond the liver to develop next-generation gene therapies.

Properties, Extraction Methods, and Delivery Systems for Curcumin as a Natural Source of Beneficial Health Effects

This review discusses the impact of curcumin-an aromatic phytoextract from the turmeric (Curcuma longa) rhizome-as an effective therapeutic agent. Despite all of the beneficial health properties ensured by curcumin application, its pharmacological efficacy is compromised in vivo due to poor aqueous solubility, high metabolism, and rapid excretion that may result in poor systemic bioavailability. To overcome these problems, novel nanosystems have been proposed to enhance its bioavailability and bioactivity by reducing the particle size, the modification of surfaces, and the encapsulation efficiency of curcumin with different nanocarriers. The solutions based on nanotechnology can improve the perspective for medical patients with serious illnesses. In this review, we discuss commonly used curcumin-loaded bio-based nanoparticles that should be implemented for overcoming the innate constraints of this natural ingredient. Furthermore, the associated challenges regarding the potential applications in combination therapies are discussed as well.

Interaction of Lipoplex with Albumin Enhances Gene Expression in Hepatitis Mice

Understanding the in vivo fate of lipoplex, which is composed of cationic liposomes and DNA, is an important issue toward gene therapy. In disease conditions, the fate of lipoplex might change compared with the normal condition. Here, we examined the contribution of interaction with serum components to in vivo transfection using lipoplex in hepatitis mice. Prior to administration, lipoplex was incubated with serum or albumin. In the liver, the interaction with albumin enhanced gene expression in hepatitis mice, while in the lung, the interaction with serum or albumin enhanced it. In normal mice, the interaction with albumin did not enhance hepatic and pulmonary gene expression. Furthermore, hepatic and pulmonary gene expression levels of albumin-interacted lipoplex were correlated with serum transaminases in hepatitis mice. The albumin interaction increased the hepatic accumulation of lipoplex and serum tumor necrosis factor-α level. We suggest that the interaction with albumin enhanced the inflammation level after the administration of lipoplex in hepatitis mice. Consequently, the enhancement of the inflammation level might enhance the gene expression level. Information obtained in the current study will be valuable toward future clinical application of the lipoplex.

Effect of Protein Corona on The Transfection Efficiency of Lipid-Coated Graphene Oxide-Based Cell Transfection Reagents

Coating graphene oxide nanoflakes with cationic lipids leads to highly homogeneous nanoparticles (GOCL NPs) with optimised physicochemical properties for gene delivery applications. In view of in vivo applications, here we use dynamic light scattering, micro-electrophoresis and one-dimensional sodium dodecyl sulfate polyacrylamide gel electrophoresis to explore the bionano interactions between GOCL/DNA complexes (hereafter referred to as "grapholipoplexes") and human plasma. When exposed to increasing protein concentrations, grapholipoplexes get covered by a protein corona that evolves with protein concentration, leading to biocoronated complexes with modified physicochemical properties. Here, we show that the formation of a protein corona dramatically changes the interactions of grapholipoplexes with four cancer cell lines: two breast cancer cell lines (MDA-MB and MCF-7 cells), a malignant glioma cell line (U-87 MG) and an epithelial colorectal adenocarcinoma cell line (CACO-2). Luciferase assay clearly indicates a monotonous reduction of the transfection efficiency of biocoronated grapholipoplexes as a function of protein concentration. Finally, we report evidence that a protein corona formed at high protein concentrations (as those present in in vivo studies) promotes a higher capture of biocoronated grapholipoplexes within degradative intracellular compartments (e.g., lysosomes), with respect to their pristine counterparts. On the other hand, coronas formed at low protein concentrations (human plasma = 2.5%) lead to high transfection efficiency with no appreciable cytotoxicity. We conclude with a critical assessment of relevant perspectives for the development of novel biocoronated gene delivery systems.

CXCL5 Modified Nanoparticle Surface Improves CXCR2+ Cell Selective Internalization

Driving nanomaterials to specific cell populations is still a major challenge for different biomedical applications. Several strategies to improve cell binding and uptake have been tried thus far by intrinsic material modifications or decoration with active molecules onto their surface. In the present work, we covalently bound the chemokine CXCL5 on fluorescently labeled amino-functionalized SiO₂ nanoparticles to precisely targeting CXCR2⁺ immune cells. We synthesized and precisely characterized the physicochemical features of the modified particles. The presence of CXCL5 on the surface was detected by z-potential variation and CXCL5-specific electron microscopy immunogold labeling. CXCL5-amino SiO₂ nanoparticle cell binding and internalization performances were analyzed in CXCR2⁺ THP-1 cells by flow cytometry and confocal microscopy. We showed improved internalization of the chemokine modified particles in the absence or the presence of serum. This internalization was reduced by cell pre-treatment with free CXCL5. Furthermore, we demonstrated CXCR2⁺ cell preferential targeting by comparing particle uptake in THP-1 vs. low-CXCR2 expressing HeLa cells. Our results provide the proof of principle that chemokine decorated nanomaterials enhance uptake and allow precise cell subset localization. The possibility to aim at selective chemokine receptor-expressing cells can be beneficial for the diverse pathological conditions involving immune reactions.

pH-responsive chimeric liposomes: From nanotechnology to biological assessment

The utilization of liposomes in biomedical applications has greatly benefited the diagnosis and treatment of various diseases. These biomimetic nano-entities have been very useful in the clinical practice as drug delivery systems in their conventional form, comprising lipids as structural components. However, the scientific efforts have recently shifted towards the development of more sophisticated nanotechnological platforms, which apply functional biomaterials, such as stimuli-responsive polymers, in order to aid the drug molecule targeting concept. These nanosystems are defined as chimeric/mixed, because they combine more than one different in nature biomaterials and their development requires intensive study through biophysical and thermodynamic approaches before they may reach in vivo application. Herein, we designed and developed chimeric liposomes, composed of a phospholipid and pH-responsive amphiphilic diblock copolymers and studied their morphology and behavior based on crucial formulation parameters, including biomaterial concentration, dispersion medium pH and polymer composition. Additionally, their interactions with biological components, pH-responsiveness and membrane thermodynamics were assessed. Finally, preliminary in vivo toxicity experiments of the developed nanosystems were carried out, in order to establish a future protocol for full in vivo evaluation. The results have been correlated with the properties of the chimeric nanosystems and highlight the importance of such approaches for designing and developing effective nanocarriers for biomedical applications.

Development of Injectable PEGylated Liposome Encapsulating Disulfiram for Colorectal Cancer Treatment

Disulfiram (DS), an anti-alcoholism medicine, shows strong anti-cancer activity in the laboratory, but the application in clinics for anti-cancer therapy has been limited by its prompt metabolism. Conventional liposomes have shown limited ability to protect DS. Therefore, the aim of this study is to develop PEGylated liposomes of DS for enhanced bio-stability and prolonged circulation. PEGylated liposomes were prepared using ethanol-based proliposome methods. Various ratios of phospholipids, namely: hydrogenated soya phosphatidylcholine (HSPC) or dipalmitoyl phosphatidylcholine (DPPC) and N-(Carbonyl-methoxypolyethylenglycol-2000)-1,2-distearoyl-sn-glycero-3-phosphoethanolamine (DSPE-PEG₂₀₀₀) with cholesterol were used. DS was dissolved in the alcoholic solution in different lipid mol% ratios. The size of the resulting multilamellar liposomes was reduced by high-pressure homogenization. Liposomal formulations were characterized by size analysis, zeta potential, drug loading efficiency and stability in horse serum. Small unilamellar vesicles (SUVs; nanoliposomes) were generated with a size of approximately 80 to 120 nm with a polydispersity index (PDI) in the range of 0.1 to 0.3. Zeta potential values of all vesicles were negative, and the negative surface charge intensity tended to increase by PEGylation. PEGylated liposomes had a smaller size (80–90 nm) and a significantly lower PDI. All liposomes showed similar loading efficiencies regardless of lipid type (HSPC or DPPC) or PEGylations. PEGylated liposomes provided the highest drug biostability amongst all formulations in horse serum. PEGylated DPPC liposomes had t_1/2 =77.3 ± 9.6 min compared to 9.7 ± 2.3 min for free DS. In vitro cytotoxicity on wild type and resistant colorectal cancer cell lines was evaluated by MTT assay. All liposomal formulations of DS were cytotoxic to both the wild type and resistant colorectal cancer cell lines and were able to reverse chemoresistance at low nanomolar concentrations. In conclusion, PEGylated liposomes have a greater potential to be used as an anticancer carrier for disulfiram.

A comprehensive analysis of liposomal biomolecular corona upon human plasma incubation: The evolution towards the lipid corona

When drug nanocarriers enter a physiological environment, their surface gets coated by a dynamic biomolecular corona (BMC) mainly constituted by proteins. Although a deep investigation has been performed on the composition of BMC in terms of proteins, scarce attention has been posed to low molecular weight metabolites present in human plasma. In this work, for the first time, the investigation of the BMC of liposomal nanoparticles (NPs) constituted by 1,2-dioleoyl-3-trimethylammonium-propane polar lipid has been carried out by an ultra-high performance liquid chromatography coupled to high-resolution mass spectrometry based untargeted metabolomics approach. Compounds were tentatively identified based on matches with online databases and comparison of MS/MS spectra with available spectral libraries. Moreover, a comparison of three metabolite extraction strategies, including an ultrafiltration membrane based protocol, a methanol extraction based protocol, and Wessel & Flügge protocol, was performed. Methanol extraction procedure resulted in the widest metabolic coverage of liposomal NP BMC. A total of 193 metabolites has been tentatively identified, 166 of which belonged to the class of lipids including phospholipids, steroids, carnitines, fatty alcohols, diglycerides and fatty acids. The high abundance of lipids in the BMC can be explained by the adsorption of plasma lipoproteins onto liposome surface, confirming previous works on other kinds of NPs. Lipids are important bioactive molecules, which could impact NP circulation and uptake by cells. Extending the investigation of BMC beyond the protein corona and towards the "lipid corona" may be the keystone of a better understanding and control of NP fate in human body.

Fluorescence correlation spectroscopy as a tool for the study of the intracellular dynamics and biological fate of protein corona

In biological fluids, nanoparticles (NPs) are in contact with proteins and other biomolecules. Proteins adsorb to NPs and form a coating called a protein corona (PC). The PC is known to greatly affect the interaction of NPs with biological systems. A comprehensive knowledge of the protein nanoparticle interaction is essential to understand the biological fate of NPs and for the design of NPs for biomedicine. Fluorescence correlation spectroscopy (FCS) and fluorescence cross-correlation spectroscopy (FCCS) are sensitive spectroscopy techniques that measure fluorescence intensity fluctuations of single molecules inside a femtoliter confocal volume. Both techniques are suitable for studying the formation of protein corona around NPs and for examining corona stability in situ in biological matrixes. In this review we provide a short description of FCS/FCCS and their application in PC studies, highlighting results from our work about the impact of surface chemistry of NPs on corona formation and NP intracellular fate.

Protein Adsorption: A Feasible Method for Nanoparticle Functionalization?

Nanomaterials are now well-established components of many sectors of science and technology. Their sizes, structures, and chemical properties allow for the exploration of a vast range of potential applications and novel approaches in basic research. Biomedical applications, such as drug or gene delivery, often require the release of nanoparticles into the bloodstream, which is populated by blood cells and a plethora of small peptides, proteins, sugars, lipids, and complexes of all these molecules. Generally, in biological fluids, a nanoparticle’s surface is covered by different biomolecules, which regulate the interactions of nanoparticles with tissues and, eventually, their fate. The adsorption of molecules onto the nanomaterial is described as “corona” formation. Every blood particulate component can contribute to the creation of the corona, although small proteins represent the majority of the adsorbed chemical moieties. The precise rules of surface-protein adsorption remain unknown, although the surface charge and topography of the nanoparticle seem to discriminate the different coronas. We will describe examples of adsorption of specific biomolecules onto nanoparticles as one of the methods for natural surface functionalization, and highlight advantages and limitations. Our critical review of these topics may help to design appropriate nanomaterials for specific drug delivery.