Effect of nanoparticle size and PEGylation on the protein corona of PLGA nanoparticles

Polymeric nanoparticles decorated with fragmented chitosan as modulation systems for neuronal drug uptake

This study aimed to modify chitosan (CS) by gamma irradiation and use it as a surface coating of nanoparticles (NPs) fabricated of poly lactic-co-glycolic acid (PLGA) to create mostly biocompatible nanosystems that can transport drugs to neurons. Gamma irradiation produced irradiated CS (CSγ) with a very low molecular weight (15.2-19.2 kDa). Coating NPs-PLGA with CSγ caused significant changes in their Z potential, making it slightly positive (from -21.7 ± 2.8 mV to +7.1 ± 2.3 mV) and in their particle size (184.4 0.4 ± 7.9 nm to 211.9 ± 14.04 nm). However, these changes were more pronounced in NPs coated with non-irradiated CS (Z potential = +54.0 ± 1.43 mV, size = 348.1 ± 16.44 nm). NPs coated with CSγ presented lower cytotoxicity and similar internalization levels in SH-SY5Y neuronal cells than NPs coated with non-irradiated CS, suggesting higher biocompatibility. Highly biocompatible NPs are desirable as nanocarriers to deliver drugs to the brain, as they help maintain the structure and function of the blood-brain barrier. Therefore, the NPs developed in this study could be evaluated as drug-delivery systems for treating brain diseases.

A Concise Review on Effect of PEGylation on the Properties of Lipid-Based Nanoparticles

Nanoparticle-based drug delivery systems have emerged as promising platforms for enhancing therapeutic efficacy while minimizing off-target effects. Among various strategies employed to optimize these systems, polyethylene glycol (PEG) modification, known as PEGylation-the covalent attachment of PEG to nanoparticles, has gained considerable attention for its ability to impart stealth properties to nanoparticles while also extending circulation time and improving biocompatibility. PEGylation extends to different drug delivery systems, in specific, nanoparticles for targeting cancer cells, where the concentration of drug in the cancer cells is improved by virtue of PEGylation. The primary challenge linked to PEGylation lies in its confirmation. Numerous research findings provide comprehensive insights into selecting PEG for various PEGylation methods. In this review, we have endeavored to consolidate the outcomes concerning the choice of PEG and diverse PEGylation techniques.

Boosting Checkpoint Immunotherapy with Biomimetic Nanodrug Delivery Systems

Immune checkpoint blockade (ICB) has achieved unprecedented progress in tumor immunotherapy by blocking specific immune checkpoint molecules. However, the high biodistribution of the drug prevents it from specifically targeting tumor tissues, leading to immune-related adverse events. Biomimetic nanodrug delivery systems (BNDSs) readily applicable to ICB therapy have been widely developed at the preclinical stage to avoid immune-related adverse events. By exploiting or mimicking complex biological structures, the constructed BNDS as a novel drug delivery system has good biocompatibility and certain tumor-targeting properties. Herein, the latest findings regarding the aforementioned therapies associated with ICB therapy are highlighted. Simultaneously, prospective bioinspired engineering strategies can be designed to overcome the four-level barriers to drug entry into lesion sites. In future clinical translation, BNDS-based ICB combination therapy represents a promising avenue for cancer treatment.

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

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

PLGA-based nanocarriers for combined delivery of colchicine and purpurin 18 in cancer therapy: Multimodal approach employing cancer cell spheroids

Improving the anticancer efficacy of chemotherapeutic drugs and photosensitizers requires innovative multifunctional nanoplatforms. This study introduces a chemo- and phototherapeutic drug delivery system (DDS) based on poly(lactide-co-glycolide) (PLGA) nanoparticles (NPs), both PEGylated and non-PEGylated, with a mean size of 200 ± 75 nm. Colchicine (Colch) and purpurin18 (P18) were co-encapsulated into these NPs, and their in vitro drug release profiles were investigated. The anticancer potential of these systems was evaluated across various cell lines (i.e., CaCo-2, PC-3, MCF-7, and MRC-5 cells), demonstrating enhanced NP uptake by cancer cells compared to free drugs. Co-administration of Colch and P18 in 2D and 3D cell line models exhibited a synergistic effect, harnessing both chemotherapeutic and photodynamic effects, leading to higher cancer cell elimination efficacy. This newly developed multifunctional DDS presents a promising platform for combined chemo- and photodynamic therapy in cancer treatment.

Rescuing a Troubled Tolcapone with PEGylated PLGA Nanoparticles: Design, Characterization, and Hepatotoxicity Evaluation

Tolcapone is an orally active catechol-O-methyltransferase (COMT) inhibitor used as adjuvant therapy in Parkinson's disease. However, it has a highly hepatotoxic profile, as recognized by the U.S. Food and Drug Administration. As a possible solution, nanoscience brought us several tools in the development of new functional nanomaterials with tunable physicochemical properties, which can be part of a solution to solve several drawbacks, including drug's short half-life and toxicity. This work aims to use PEGylated poly(lactic-co-glycolic acid) (PLGA) nanoparticles as a stable carrier with lower hydrodynamic size and polydispersity to encapsulate tolcapone in order to overcome its therapeutic drawbacks. Using the nanoprecipitation method, tolcapone-loaded nanoparticles with a DLC% of 5.7% were obtained (EE% of 47.0%) and subjected to a lyophilization optimization process to obtain a final shelf-stable formulation. Six different cryoprotectants in concentrations up to 10% (w/v) were tested. A formulation of PLGA nanoparticles with 3% hydroxypropyl-β-cyclodextrin (HPβCD) as a cryoprotectant (PLGA-HP@Tolc), presenting sub-200 nm sizes and low polydispersity (PdI < 0.200) was selected. Cytotoxicity assays, namely, MTT and SRB, were used to study the metabolic activity and cell density of tolcapone and PLGA-HP@Tolc-treated cells. In both assays, a hepatocarcinoma cell line (HepG2) growing in glucose or glucose-free media (galactose-supplemented medium) was used. The results demonstrated that the treatment with the PLGA-HP@Tolc formulation led to a decrease in cytotoxicity in comparison to free tolcapone-treated cells in both media tested. Moreover, the elected formulation also counteracted ATP-depletion and excessive ROS production induced by tolcapone. The results suggest that HPβCD might have a dual function in the formulation: cryoprotectant and anticytotoxic agent, protecting cells from tolcapone-induced damage. Using an in vitro COMT inhibition assay, the PLGA-HP@Tolc formulation demonstrated to inhibit COMT as efficiently as free tolcapone. Overall, the results suggest that tolcapone-loaded PLGA NPs could be an interesting alternative to free tolcapone, demonstrating the same in vitro efficacy in inhibiting COMT but with a safer cytotoxic profile.

The interaction between particles and vascular endothelium in blood flow

Particle-based drug delivery systems have shown promising application potential to treat human diseases; however, an incomplete understanding of their interactions with vascular endothelium in blood flow prevents their inclusion into mainstream clinical applications. The flow performance of nano/micro-sized particles in the blood are disturbed by many external/internal factors, including blood constituents, particle properties, and endothelium bioactivities, affecting the fate of particles in vivo and therapeutic effects for diseases. This review highlights how the blood constituents, hemodynamic environment and particle properties influence the interactions and particle activities in vivo. Moreover, we briefly summarized the structure and functions of endothelium and simulated devices for studying particle performance under blood flow conditions. Finally, based on particle-endothelium interactions, we propose future opportunities for novel therapeutic strategies and provide solutions to challenges in particle delivery systems for accelerating their clinical translation. This review helps provoke an increasing in-depth understanding of particle-endothelium interactions and inspires more strategies that may benefit the development of particle medicine.

Probing Protein Corona Formation around Gold Nanoparticles: Effects of Surface Coating

There has been much interest in integrating various inorganic nanoparticles (nanoscale colloids) in biology and medicine. However, buildup of a protein corona around the nanoparticles in biological media, driven by nonspecific interactions, remains a major hurdle for the translation of nanomedicine into clinical applications. In this study, we investigate the interactions between gold nanoparticles and serum proteins using a series of dihydrolipoic acid (DHLA)-based ligands. We employed gel electrophoresis combined with UV-vis absorption and dynamic light scattering to correlate protein adsorption with the nature and size of the ligand used. For instance, we found that AuNPs capped with DHLA alone promote nonspecific protein adsorption. In comparison, capping AuNPs with polyethylene glycol- or zwitterion-appended DHLA essentially prevents corona formation, regardless of ligand charge and size. Our results highlight the crucial role of surface chemistry and core material in protein corona formation and offer valuable information for the design of colloidal nanomaterials for biological applications.

Synthesis, characterization and multi-spectroscopic DNA/HSA interaction studies of synthetic human Follicle-Stimulating Hormone Beta 33-53 peptide conjugated PEGylated graphene oxide nanoparticles

The objective of the current study was to synthesize, characterize and explore the interaction of PEGylated graphene oxide (pGO) and synthetic human Follicular stimulating hormone β 33-53 peptide conjugated PEGylated graphene oxide nanoparticles (pGO-FSH) with human serum albumin (HSA) and calf thymus DNA (CT-DNA). The pGO/ pGO-FSH nanoparticles were synthesized using a modified Hummer's method, and the FSH peptide was conjugated through a maleimide crosslinking reaction. Synthesized nanoparticles were then characterized using techniques like FT-IR, UV-Visible absorbance, CD and Raman spectroscopy, and XRD and TGA. Morphological and particle size analysis was studied using SEM, TEM, DLS, and zeta potential measurements. The presence of FSH β 33-53 peptide was confirmed qualitatively and quantitatively using CD spectroscopy and Bradford's assay. Binding studies of pGO/pGO-FSH nanoparticles with HSA and DNA were carried out using biophysical techniques. The complex formation between pGO/pGO-FSH nanoparticles and HSA was revealed by UV absorbance spectroscopy, and the observed fluorescence quenching was confirmed by steady-state fluorescence spectroscopy. Time-resolved fluorescence quenching studies have shown that dynamic quenching plays an important role in binding HSA with pGO/pGO-FSH nanoparticles. However, structurally no significant changes were observed in the native structure of HSA upon binding with pGO/pGO-FSH nanoparticles suggesting that the latter did not induce any structural distortions together, confirmed by DSC, FT-IR, and CD spectroscopy experimental findings. Binding constants and thermodynamic parameters calculated using double logarithmic and Van't Hoff plots suggested weak and moderate binding affinity along with the involvement of hydrophobic and hydrogen bonding interactions between HSA and pGO/pGO-FSH nanoparticles, respectively. UV absorbance and fluorescence spectroscopy have revealed that pGO/pGO-FSH nanoparticles interact with DNA by binding at the minor groove region. These findings were further confirmed by DNA melting and viscosity studies. CD and FT-IR spectroscopy studies have shown no changes in the helical structure of B-form of DNA, thereby emphasizing the groove-binding nature of pGO/pGO-FSH nanoparticles. The obtained results are useful in further considering the potentiality of pGO-FSH nanoparticles as drug-delivery systems for in vivo applications, especially to target ovarian cancer.

Effect of ligand and shell densities on the surface structure of core-shell nanoparticles self-assembled from function-spacer-lipid constructs

Biomolecular corona is the major obstacle to the clinical translation of nanomedicines. Since corona formation is governed by molecular interactions at the nano-bio interface, nanoparticle surface properties such as topography, charge and surface chemistry can be tuned to manipulate biomolecular corona formation. To this end, as the first step towards a deep understanding of the processes of corona formation, it is necessary to develop nanoparticles employing various biocompatible materials and characterize their surface structure and dynamics at the molecular level. In this work, we applied molecular dynamics simulation to study the surface structure of organic core-shell nanoparticles formed by the self-assembly of synthetic molecules composed of a DOPE lipid, a carboxymethylglycine spacer and biotin. Lipid moieties form the hydrophobic core, spacer motifs serve as a hydrophilic shell and biotin residues function as a targeting ligand. By mixing such function-spacer-lipid, spacer-lipid and lipid-only constructs at various molar ratios, densities of the ligand and spacer on the nanoparticle surface were modified. For convenient analysis of the structure and dynamics of all regions of the nanoparticle surface, we compiled topography maps based on atomic coordinates. It was shown that an increase in the density of the shell does not reduce exposure of the core, but increases shell average thickness. Biotin, due to its alkyl valeric acid chain and spacer flexibility, is localized primarily near the hydrophobic core and its partial presentation on the surface occurs only in nanoparticles with higher ligand densities. However, an increase in biotin density leads to its clustering. In turn, ligand clustering diminishes the stealth properties of the shell and targeting efficiency. Based on nanoparticle surface structures, we determined the optimal density of biotin. Experimental studies reported in the literature confirm these conclusions. We also suggest design tips to achieve the preferred biotin presentation. Simulation results are consistent with the synchrotron SAXS profile. We believe that such studies will contribute to a better understanding of nano-bio interactions towards the rational design of efficient drug delivery systems.

House Dust Mite Extract Forms a Der p 2 Corona on Multi-Walled Carbon Nanotubes: Implications for Allergic Airway Disease

Multi-walled carbons nanotubes (MWCNTs) are used in materials for the construction, automotive, and aerospace industries. Workers and consumers are exposed to these materials via inhalation. Existing recommended exposure limits are based on MWCNT exposures that do not take into account more realistic co-exposures. Our goal was to understand how a common allergen, house dust mites, interacts with pristine MWCNTs and lung fluid proteins. We used gel electrophoresis, western blotting, and proteomics to characterize the composition of the allergen corona formed from house dust mite extract on the surface of MWCNTs. We found that the corona is dominated by der p 2, a protein associated with human allergic responses to house dust mites. Der p 2 remains adsorbed on the surface of the MWCNTs following subsequent exposures to lung fluid proteins. The high concentration of der p 2, localized on surface of MWCNTs, has important implications for house dust mite-induced allergies and asthma. This research provides a detailed characterization of the complex house dust mite-lung fluid protein coronas for future cellular and in vivo studies. These studies will help to address the molecular and biochemical mechanisms underlying the exacerbation of allergic lung disease by nanomaterials.

Protein corona, influence on drug delivery system and its improvement strategy: A review

Nano drug delivery systems offer several benefits, including enhancing drug solubility, regulating drug release, prolonging drug circulation time, and minimized toxicity and side effects. However, upon entering the bloodstream, nanoparticles (NPs) encounter a complex biological environment and get absorbed by various biological components, primarily proteins, leading to the formation of a 'Protein Corona'. The formation of the protein corona is affected by the characteristics of NPs, the physiological environment, and experimental design, which in turn affects of the immunotoxicity, specific recognition, cell uptake, and drug release of NPs. To improve the abundance of a specific protein on NPs, researchers have explored pre-coating, modifying, or wrapping NPs with the cell membrane to reduce protein adsorption. This paper, we have reviewed studies of the protein corona in recent years, summarized the formation and detection methods of the protein corona, the effect of the protein corona composition on the fate of NPs, and the design of new drug delivery systems based on the optimization of protein corona to provide a reference for further study of the protein corona and a theoretical basis for the clinical transformation of NPs.

Characterization of Dye-Loaded Poly(lactic-co-glycolic acid) Nanoparticles by Comprehensive Two-Dimensional Liquid Chromatography Combining Hydrodynamic and Reversed-Phase Liquid Chromatography

Analytical methods for the assessment of drug-delivery systems (DDSs) are commonly suitable for characterizing individual DDS properties, but do not allow determination of several properties simultaneously. A comprehensive online two-dimensional liquid chromatography (LC × LC) system was developed that is aimed to be capable of characterizing both nanoparticle size and encapsulated cargo over the particle size distribution of a DDS by using one integrated method. Polymeric nanoparticles (NPs) with encapsulated hydrophobic dyes were used as model DDSs. Hydrodynamic chromatography (HDC) was used in the first dimension to separate the intact NPs and to determine the particle size distribution. Fractions from the first dimension were taken comprehensively and disassembled online by the addition of an organic solvent, thereby releasing the encapsulated cargo. Reversed-phase liquid chromatography (RPLC) was used as a second dimension to separate the released dyes. Conditions were optimized to ensure the complete disassembly of the NPs and the dissolution of the dyes during the solvent modulation step. Subsequently, stationary-phase-assisted modulation (SPAM) was applied for trapping and preconcentration of the analytes, thereby minimizing the risk of analyte precipitation or breakthrough. The developed HDC × RPLC method allows for the characterization of encapsulated cargo as a function of intact nanoparticle size and shows potential for the analysis of API stability.

Intracellular Trafficking of Size-Tuned Nanoparticles for Drug Delivery

Polymeric nanoparticles (NPs) are widely used as drug delivery systems in nanomedicine. Despite their widespread application, a comprehensive understanding of their intracellular trafficking remains elusive. In the present study, we focused on exploring the impact of a 20 nm difference in size on NP performance, including drug delivery capabilities and intracellular trafficking. For that, poly(ethylene glycol) methyl ether-block-poly(lactide-co-glycolide) (PLGA-PEG) NPs with sizes of 50 and 70 nm were precisely tailored. To assess their prowess in encapsulating and releasing therapeutic agents, we have employed doxorubicin (Dox), a well-established anticancer drug widely utilized in clinical settings, as a model drug. Then, the beneficial effect of the developed nanoformulations was evaluated in breast cancer cells. Finally, we performed a semiquantitative analysis of both NPs' uptake and intracellular localization by immunostaining lysosomes, early endosomes, and recycling endosomes. The results show that the smaller NPs (50 nm) were able to reduce the metabolic activity of cancer cells more efficiently than NPs of 70 nm, in a time and concentration-dependent manner. These findings are corroborated by intracellular trafficking studies that reveal an earlier and higher uptake of NPs, with 50 nm compared to the 70 nm ones, by the breast cancer cells. Consequently, this study demonstrates that NP size, even in small increments, has an important impact on their therapeutic effect.

Sample transformation in online separations: how chemical conversion advances analytical technology

While the advent of modern analytical technology has allowed scientists to determine the complexity of mixtures, it also spurred the demand to understand these sophisticated mixtures better. Chemical transformation can be used to provide insights into properties of complex samples such as degradation pathways or molecular heterogeneity that are otherwise unaccessible. In this article, we explore how sample transformation is exploited across different application fields to empower analytical methods. Transformation mechanisms include molecular-weight reduction, controlled degradation, and derivatization. Both offline and online transformation methods have been explored. The covered studies show that sample transformation facilitates faster reactions (e.g. several hours to minutes), reduces sample complexity, unlocks new sample dimensions (e.g. functional groups), provides correlations between multiple sample dimensions, and improves detectability. The article highlights the state-of-the-art and future prospects, focusing in particular on the characterization of protein and nucleic-acid therapeutics, nanoparticles, synthetic polymers, and small molecules.

Interactions between nanoparticle corona proteins and the immune system

The corona surrounding nanoparticles (NPs) in serum contains proteins such as complement, immunoglobulins, and apolipoproteins that can interact with the immune system. This review article describes the impact of these interactions on nanomedicine stability, biodistribution, efficacy, and safety. Notably, it highlights the latest findings on the generation of antibody responses to the polyethylene glycol (PEG) component of SARS-CoV-2 mRNA vaccines and possible mechanisms of hypersensitivity reactions induced by antibodies that bind to NPs. Finally, we briefly outline how the NP interactions with immune cells can be harnessed to enhance targeted delivery of nanocargos to disease sites.

Composition-Dependent Protein-Material Interaction of Poly(Methyl Methacrylate-co-styrene) Nanoparticle Series

Polymer nanoparticles continue to be of high interest in life science applications. Still, adsorption processes occurring in protein-containing media and their implications for biological responses are not generally predictable. Here, the effect of nanoparticle composition on the adsorption of bovine serum albumin (BSA), fibronectin (FN) and immunoglobulin G (IgG) as structurally and functionally different model proteins was explored by systematically altering the composition of poly(methyl methacrylate-co-styrene) nanoparticles with sizes in a range of about 550 nm. As determined by protein depletion from the suspension medium via a colorimetric assay, BSA and IgG adsorbed at similar quantities, while FN reached larger masses of adsorbed protein (up to 0.4 ± 0.06 µg·cm-2 BSA, 0.42 ± 0.09 µg·cm-2 IgG, 0.72 ± 0.04 µg·cm-2 FN). A higher content of styrene as the more hydrophobic polymer component enhanced protein binding, which suggests a contribution of hydrophobic interactions despite the particles exhibiting strongly negatively charged surfaces with zeta potentials of -44 to -52 mV. The quantities of adsorbed proteins were estimated to correspond to a confluent surface coverage. Overall, this study illustrated how protein binding can be controlled by systematically varying the nanoparticle bulk composition and may serve as a basis for establishing interfaces with a targeted level of protein retention and/or presentation.

Protein corona formation on lipidic nanocapsules: Influence of the interfacial PEG repartition

The parameters currently used for characterization of nanoparticles, such as size and zeta potential, were not able to reflect the performance of a nanocarrier in the biological environment. Therefore, more thorough in vitro characterization is required to predict their behavior in vivo, where nanoparticles acquire a new biological identity due to interactions with biomolecules. In this present study, we performed in vitro characterization in biological fluids for lipid nanocapsules (LNCs) with varying means sizes (50 nm and 100 nm), different electrical surface charges and different Poly Ethylene Glycol (PEG) compositions. Then, different methods were applied to show the impact of the protein corona formation on LNCs. Even if all formulations attached to plasmatic proteins, a higher thickness of corona and highest protein binding was observed for certain LNC50 formulations. A better knowledge of the phenomenon of protein adsorption over NPs in the plasmatic media is a cornerstone of clinical translation. In fact, after short blood circulation time, it is not the initially designed nanoparticle but the complex nanoparticle bearing its protein corona which circulates to reach its target.

The Recent Applications of PLGA-Based Nanostructures for Ischemic Stroke

With the accelerated development of nanotechnology in recent years, nanomaterials have become increasingly prevalent in the medical field. The poly (lactic acid-glycolic acid) copolymer (PLGA) is one of the most commonly used biodegradable polymers. It is biocompatible and can be fabricated into various nanostructures, depending on requirements. Ischemic stroke is a common, disabling, and fatal illness that burdens society. There is a need for further improvement in the diagnosis and treatment of this disease. PLGA-based nanostructures can facilitate therapeutic compounds' passage through the physicochemical barrier. They further provide both sustained and controlled release of therapeutic compounds when loaded with drugs for the treatment of ischemic stroke. The clinical significance and potential of PLGA-based nanostructures can also be seen in their applications in cell transplantation and imaging diagnostics of ischemic stroke. This paper summarizes the synthesis and properties of PLGA and reviews in detail the recent applications of PLGA-based nanostructures for drug delivery, disease therapy, cell transplantation, and the imaging diagnosis of ischemic stroke.

Effect of Composition and Size on Surface Properties of Anti-Cancer Nanoparticles

Liposomal formulations offer significant advantages as anticancer drug carriers for targeted drug delivery; however, due to their complexity, clinical translation has been challenging. In addition, liposomal product manufacturing has been interrupted in the past, as was the case for Doxil® (doxorubicin hydrochloride liposome injection). Here, interfacial tension (IFT) measurements were investigated as a potential physicochemical characterization tool to aid in liposomal product characterization during development and manufacturing. A pendant drop method using an optical tensiometer was used to measure the interfacial tension of various analogues of Doxil® liposomal suspensions in air and in dodecane. The effect of liposome concentration, formulation (PEG and cholesterol content), presence of encapsulated drug, as well as average particle size was analyzed. It was observed that Doxil® analog liposomes demonstrate surfactant-like behavior with a sigmoidal-shape interfacial tension vs. concentration curve. This behavior was heavily dependent on PEG content, with a complete loss of surfactant-like behavior when PEG was removed from the formulation. In addition to interfacial tension, three data analyses were identified as able to distinguish between formulations with variations in PEG, cholesterol, and particle size: (i) polar and non-polar contribution to interfacial tension, (ii) liposomal concentration at which the polar and non-polar components were equal, and (iii) rate of interfacial tension decay after droplet formation, which is indicative of how quickly liposomes migrate from the bulk of the solution to the surface. We demonstrate for the first time that interfacial tension can be used to detect certain liposomal formulation changes, such as PEG content, encapsulated drug presence, and size variability, and may make a useful addition to physicochemical characterization during development and manufacturing of liposomal products.

Nanomedicine in cancer therapy

Cancer remains a highly lethal disease in the world. Currently, either conventional cancer therapies or modern immunotherapies are non-tumor-targeted therapeutic approaches that cannot accurately distinguish malignant cells from healthy ones, giving rise to multiple undesired side effects. Recent advances in nanotechnology, accompanied by our growing understanding of cancer biology and nano-bio interactions, have led to the development of a series of nanocarriers, which aim to improve the therapeutic efficacy while reducing off-target toxicity of the encapsulated anticancer agents through tumor tissue-, cell-, or organelle-specific targeting. However, the vast majority of nanocarriers do not possess hierarchical targeting capability, and their therapeutic indices are often compromised by either poor tumor accumulation, inefficient cellular internalization, or inaccurate subcellular localization. This Review outlines current and prospective strategies in the design of tumor tissue-, cell-, and organelle-targeted cancer nanomedicines, and highlights the latest progress in hierarchical targeting technologies that can dynamically integrate these three different stages of static tumor targeting to maximize therapeutic outcomes. Finally, we briefly discuss the current challenges and future opportunities for the clinical translation of cancer nanomedicines.

Polymeric Nanoparticles and Nanogels: How Do They Interact with Proteins?

Polymeric nanomaterials, nanogels, and solid nanoparticles can be fabricated using single or double emulsion methods. These materials hold great promise for various biomedical applications due to their biocompatibility, biodegradability, and their ability to control interactions with body fluids and cells. Despite the increasing use of nanoparticles in biomedicine and the plethora of publications on the topic, the biological behavior and efficacy of polymeric nanoparticles (PNPs) have not been as extensively studied as those of other nanoparticles. The gap between the potential of PNPs and their applications can mainly be attributed to the incomplete understanding of their biological identity. Under physiological conditions, such as specific temperatures and adequate protein concentrations, PNPs become coated with a "protein corona" (PC), rendering them potent tools for proteomics studies. In this review, we initially investigate the synthesis routes and chemical composition of conventional PNPs to better comprehend how they interact with proteins. Subsequently, we comprehensively explore the effects of material and biological parameters on the interactions between nanoparticles and proteins, encompassing reactions such as hydrophobic bonding and electrostatic interactions. Moreover, we delve into recent advances in PNP-based models that can be applied to nanoproteomics, discussing the new opportunities they offer for the clinical translation of nanoparticles and early prediction of diseases. By addressing these essential aspects, we aim to shed light on the potential of polymeric nanoparticles for biomedical applications and foster further research in this critical area.

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

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

Analysis of PEG-lipid anchor length on lipid nanoparticle pharmacokinetics and activity in a mouse model of traumatic brain injury

Traumatic brain injury (TBI) affects millions of people worldwide, yet there are currently no therapeutics that address the long-term impairments that develop in a large portion of survivors. Lipid nanoparticles (LNPs) are a promising therapeutic strategy that may address the molecular basis of TBI pathophysiology. LNPs are the only non-viral gene delivery platform to achieve clinical success, but systemically administered formulations have only been established for targets in the liver. In this work, we evaluated the pharmacokinetics and activity of LNPs formulated with polyethylene glycol (PEG)-lipids of different anchor lengths when systemically administered to a mouse model of TBI. We observed an increase in LNP accumulation and activity in the injured brain hemisphere compared to the uninjured contralateral brain hemisphere. Interestingly, transgene expression mediated by LNPs was more durable in injured brain tissue compared to off-target organs when compared between 4 and 24 hours. The PEG-lipid is an important component of LNP formulation necessary for the stable formation and storage of LNPs, but the PEG-lipid structure and content also has an impact on LNP function. LNP formulations containing various ratios of PEG-lipid with C18 (DSPE-PEG) and C14 (DMG-PEG) anchors displayed similar physicochemical properties, independent of the PEG-lipid compositions. As the proportion of DSPE-PEG was increased in formulations, blood circulation times of LNPs increased and the duration of expression increased. We also evaluated diffusion of LNPs after convection enhanced delivery (CED) in healthy brains and found LNPs distributed >1 mm away from the injection site. Understanding LNP pharmacokinetics and activity in TBI models and the impact of PEG-lipid anchor length informs the design of LNP-based therapies for TBI after systemic administration.

Impact of pH on the Formation and Properties of Whey Protein Coronas around TiO2 Nanoparticles

In aqueous media, titanium dioxide (TiO₂) nanoparticles can interact with proteins in their environment and form a protein corona. The pH of the aqueous media affects the structure and properties of the protein corona, and currently there is a lack of understanding of the effects of pH on the characteristics of protein coronas. In this study, we examined the impact of pH (2-11) on the structural and physicochemical properties of whey protein coronas formed around TiO₂ nanoparticles. The pH of the solution influenced the structure of whey protein molecules, especially around their isoelectric point. Thermogravimetric and quartz crystal microbalance analyses showed that the adsorption capacity of the whey proteins was the largest at their isoelectric points and the lowest under highly acidic or alkaline conditions. The majority of the proteins were tightly bound to the nanoparticle surfaces, forming a hard corona. The influence of solution pH on protein corona properties was mainly attributed to its impact on the electrostatic forces in the system, which impacted the protein conformation and interactions. This study provides useful insights into the influence of pH on the formation and properties of protein coronas around inorganic nanoparticles, which may be important for understanding the gastrointestinal and environmental fates.

On the size-dependent internalization of sub-hundred polymeric nanoparticles

The understanding of the interaction between nanoparticles (NPs) and cells is crucial to design nanocarriers with high therapeutic relevance. In this study, we exploited a microfluidics device to synthesize homogeneous suspensions of NPs with ≈ 30, 50, and 70 nm of size. Afterward, we investigated their level and mechanism of internalization when exposed to different types of cells (endothelial cells, macrophages, and fibroblasts). Our results show that all NPs were cytocompatible and internalized by the different cell types. However, NPs uptake was size-dependent, being the maximum uptake efficiency observed for the 30 nm NPs. Moreover, we demonstrate that size can lead to distinct interactions with different cells. For instance, 30 nm NPs were internalized with an increasing trend over time by endothelial cells, while a steady and a decreasing trend were observed when incubated with LPS-stimulated macrophages and fibroblasts, respectively. Finally, the use of different chemical inhibitors (chlorpromazine, cytochalasin-D, and nystatin), and low temperature (4 °C) indicated that phagocytosis/micropinocytosis are the main internalization mechanism for all NPs sizes. However, different endocytic pathways were initiated in the presence of particular NP sizes. In endothelial cells, for example, caveolin-mediated endocytosis occurs primarily in the presence of 50 nm NPs, whereas clathrin-mediated endocytosis substantially promotes the internalization of 70 nm NPs. This evidence demonstrates the importance of size in the NPs design for mediating interaction with specific cell types.

Nanocarrier design–function relationship: The prodigious role of properties in regulating biocompatibility for drug delivery applications

The concept of drug delivery systems as a magic bullet for the delivery of bioactive compounds has emerged as a promising approach in the treatment of different diseases with significant advantages over the limitations of traditional methods. While nanocarrier-based drug delivery systems are the main advocates of drug uptake because they offer several advantages including reduced non-specific biodistribution, improved accumulation, and enhanced therapeutic efficiency; their safety and biocompatibility within cellular/tissue systems are therefore important for achieving the desired effect. The underlying power of "design-interplay chemistry" in modulating the properties and biocompatibility at the nanoscale level will direct the interaction with their immediate surrounding. Apart from improving the existing nanoparticle physicochemical properties, the balancing of the hosts' blood components interaction holds the prospect of conferring newer functions altogether. So far, this concept has been remarkable in achieving many fascinating feats in addressing many challenges in nanomedicine such as immune responses, inflammation, biospecific targeting and treatment, and so on. This review, therefore, provides a diverse account of the recent advances in the fabrication of biocompatible nano-drug delivery platforms for chemotherapeutic applications, as well as combination therapy, theragnostic, and other diseases that are of interest to scientists in the pharmaceutical industries. Thus, careful consideration of the "property of choice" would be an ideal way to realize specific functions from a set of delivery platforms. Looking ahead, there is an enormous prospect for nanoparticle properties in regulating biocompatibility.

The portrayal of macrophages as tools and targets: A paradigm shift in cancer management

Macrophages play a major role in maintaining an organism's physiology, such as development, homeostasis, tissue repair, and immunity. These immune cells are known to be involved in tumor progression and modulation. Monocytes can be polarized to two types of macrophages (M1 macrophages and pro-tumor M2 macrophages). Through this article, we aim to emphasize the potential of targeting macrophages in order to improve current strategies for tumor management. Various strategies that target macrophages as a therapeutic target have been discussed along with ongoing clinical trials. We have discussed the role of macrophages in various stages of tumor progression epithelial-to-mesenchymal transition (EMT), invasion, maintaining the stability of circulating tumor cells (CTCs) in blood, and establishing a premetastatic niche along with the role of various cytokines and chemokines involved in these processes. Intriguingly macrophages can also serve as drug carriers due to their tumor tropism along the chemokine gradient. They surpass currently explored nanotherapeutics in tumor accumulation and circulation half-life. We have emphasized on macrophage-based biomimetic formulations and macrophage-hitchhiking as a strategy to effectively target tumors. We firmly believe that targeting macrophages or utilizing them as an indigenous carrier system could transform cancer management.

Interactions of Apolipoproteins with Lipid-Based Nanoparticles

Serum proteins bind and form a dynamic protein corona around nanoparticles (NPs) that have been injected into the mammalian vasculature. Several fundamental studies have shown that apolipoproteins are prominent components of the NP corona. Since apolipoproteins control the distribution of lipoproteins, they may also control the distribution of NPs. Indeed, apolipoprotein affinity for NPs has been recently taken advantage of to deliver CRISPR reagents encapsulated in NPs to cells that express particular lipoprotein receptors. In this scenario, an apolipoprotein binds an NP and the resulting apolipoprotein-NP complex binds a cell that expresses the (apo)lipoprotein receptor. But the NP will be diverted from the target cell if it does not express the (apo)lipoprotein receptor. This may hamper NP treatment of diseases. Therefore, we must understand the kinetics of apolipoprotein-NP affinity and how apolipoprotein-NP interactions affect NP biodistribution. In this Perspective, we discuss the evolving topic of apolipoprotein-NP interactions, which is of great interest for all NP-based disease treatments. Many properties of apolipoprotein-NP complexes are yet to be determined and will have a significant impact on NP efficacy for many NP-based treatments in animal models and in the clinic.

Fn14-Directed DART Nanoparticles Selectively Target Neoplastic Cells in Preclinical Models of Triple-Negative Breast Cancer Brain Metastasis

Triple-negative breast cancer (TNBC) patients with brain metastasis (BM) face dismal prognosis due to the limited therapeutic efficacy of the currently available treatment options. We previously demonstrated that paclitaxel-loaded PLGA-PEG nanoparticles (NPs) directed to the Fn14 receptor, termed "DARTs", are more efficacious than Abraxane─an FDA-approved paclitaxel nanoformulation─following intravenous delivery in a mouse model of TNBC BM. However, the precise basis for this difference was not investigated. Here, we further examine the utility of the DART drug delivery platform in complementary xenograft and syngeneic TNBC BM models. First, we demonstrated that, in comparison to nontargeted NPs, DART NPs exhibit preferential association with Fn14-positive human and murine TNBC cell lines cultured in vitro. We next identified tumor cells as the predominant source of Fn14 expression in the TNBC BM-immune microenvironment with minimal expression by microglia, infiltrating macrophages, monocytes, or lymphocytes. We then show that despite similar accumulation in brains harboring TNBC tumors, Fn14-targeted DARTs exhibit significant and specific association with Fn14-positive TNBC cells compared to nontargeted NPs or Abraxane. Together, these results indicate that Fn14 expression primarily by tumor cells in TNBC BMs enables selective DART NP delivery to these cells, likely driving the significantly improved therapeutic efficacy observed in our prior work.

Er:Y2O3 and Nd:Y2O3 Nanoparticles: Synthesis, Pegylation, Characterization and Study of Their Luminescence Properties

Lanthanide-doped yttrium oxide nanoparticles can display selective upconversion properties, rendering them invaluable in the field of nanomedicine for both sensing and diagnostics. Different syntheses of Er:Y2O3 and Nd:Y2O3 nanoparticles (NPs) were studied and optimized to obtain small particles of regular shape and good crystallinity. The morphological and compositional characterizations of the nanoparticles were obtained with different techniques and showed that both Er:Y2O3 and Nd:Y2O3 NPs were well dispersed, with dimensions of the order of a few tens of nanometers. The photoluminescence and cathodoluminescence measurements showed that both Er:Y2O3 and Nd:Y2O3 NPs had good emission as well as upconversion. The nanophosphors were functionalized by a pegylation procedure to suppress unwanted reactions of the NPs with other biological components, making the NP systems biocompatible and the NPs soluble in water and well dispersed. The pegylated core/shell nanoparticles showed the same morphological and optical characteristics as the core, promoting their strategic role as photoactive material for theragnostics and biosensing.

PLGA-Based Nanomedicine: History of Advancement and Development in Clinical Applications of Multiple Diseases

Research on the use of biodegradable polymers for drug delivery has been ongoing since they were first used as bioresorbable surgical devices in the 1980s. For tissue engineering and drug delivery, biodegradable polymer poly-lactic-co-glycolic acid (PLGA) has shown enormous promise among all biomaterials. PLGA are a family of FDA-approved biodegradable polymers that are physically strong and highly biocompatible and have been extensively studied as delivery vehicles of drugs, proteins, and macromolecules such as DNA and RNA. PLGA has a wide range of erosion times and mechanical properties that can be modified. Many innovative platforms have been widely studied and created for the development of methods for the controlled delivery of PLGA. In this paper, the various manufacturing processes and characteristics that impact their breakdown and drug release are explored in depth. Besides different PLGA-based nanoparticles, preclinical and clinical applications for different diseases and the PLGA platform types and their scale-up issues will be discussed.

Macromolecules Absorbed from Influenza Infection-Based Sera Modulate the Cellular Uptake of Polymeric Nanoparticles

Optimizing the biological identity of nanoparticles (NPs) for efficient tumor uptake remains challenging. The controlled formation of a protein corona on NPs through protein absorption from biofluids could favor a biological identity that enables tumor accumulation. To increase the diversity of proteins absorbed by NPs, sera derived from Influenza A virus (IAV)-infected mice were used to pre-coat NPs formed using a hyperbranched polyester polymer (HBPE-NPs). HBPE-NPs, encapsulating a tracking dye or cancer drug, were treated with sera from days 3-6 of IAV infection (VS3-6), and uptake of HBPE-NPs by breast cancer cells was examined. Cancer cells demonstrated better uptake of HBPE-NPs pre-treated with VS3-6 over polyethylene glycol (PEG)-HBPE-NPs, a standard NP surface modification. The uptake of VS5 pre-treated HBPE-NPs by monocytic cells (THP-1) was decreased over PEG-HBPE-NPs. VS5-treated HBPE-NPs delivered a cancer drug more efficiently and displayed better in vivo distribution over controls, remaining stable even after interacting with endothelial cells. Using a proteomics approach, proteins absorbed from sera-treated HBPE-NPs were identified, such as thrombospondin-1 (TSP-1), that could bind multiple cancer cell receptors. Our findings indicate that serum collected during an immune response to infection is a rich source of macromolecules that are absorbed by NPs and modulate their biological identity, achieving rationally designed uptake by targeted cell types.

Surface Engineering of Protein Nanoparticles Modulates Transport, Adsorption, and Uptake in Mucus

Protein nanoparticles have been demonstrated as effective carriers for protein antigens and therapeutics due to properties endowed by their protein composition. They exhibit high protein to carrier yields, biocompatibility, and heterogeneous surface properties. While protein nanoparticles have been delivered via multiple routes, including intranasal, their interactions with mucosal barriers have not been well studied or modified. Biological barriers associated with intranasal delivery consist of viscoelastic mucus that hinders material transport through surface interactions and the underlying epithelium. Herein, we altered protein nanoparticle surface properties and characterized interactions with nasal mucus and the subsequent effects on diffusion, cellular uptake, and immune cell maturation. Ovalbumin protein nanoparticles were used, serving as a model vaccine nanoparticle. Unmodified ovalbumin protein nanoparticles were compared to cationic ovalbumin particles functionalized with amine groups, neutral particles functionalized with polyethylene glycol, and zwitterionic particles coated layer-by-layer (LBL) with chitosan and oligonucleotides. Transport analysis indicated rapid diffusion of polyethylene glycol and LBL-modified ovalbumin nanoparticles in porcine nasal mucus, while cationic particles were mucoadhesive. Cellular uptake in the presence of mucus by epithelial and dendritic cells was highest for particles containing positive charges, both LBL and amine-functionalized. These particles also exhibited the most diverse adsorbed protein corona from nasal fluids. The corona impacted both dendritic cell uptake and maturation, with polyethylene glycol and LBL modifications improving CD86 expression. Altogether, surface modifications on protein-based nanocarriers are shown to facilitate distinctive physical and cellular behavior associated with mucosal delivery.

Proteomic Analysis Reveals Distinct Protein Corona Compositions of Citrate- and Riboflavin-Coated SPIONs

Superparamagnetic iron oxide nanoparticles (SPIONs) are recognized as one of the most beneficial tools for biomedicine, especially in theranostic applications. Even though SPIONs have excellent properties regarding their biocompatibility and unique magnetic properties, they lack stability in biological fluids. To stabilize and increase the specificity of the SPIONs to target desirable cells or tissues, several surface coatings have been introduced. These surface coatings can lead to different preferences of serum protein bindings, which ultimately determine their behaviors in vitro and in vivo. Thus, understanding the interaction of SPIONs with biological systems is important for their biocompatible design and clinical applications. In this study, using proteomic analyses, we analyzed the protein corona fingerprints on SPIONs with two different coatings, including citrate and riboflavin, that have been widely used as surface coatings and ligands for enhancing cellular uptake in breast cancer cells. Though both citrate-coated SPIONs (C-SPIONs) and riboflavin-coated SPIONs (Rf-SPIONs) showed similar sizes and zeta potentials, we found that Rf-SPIONs adsorbed more serum proteins than bare SPIONs (B-SPIONs) or C-SPIONs, which was likely due to the higher hydrophobicity of the riboflavin. The enriched proteins consisted mainly of immune-responsive and blood coagulation proteins with different fingerprint profiles. Cellular uptake studies in MCF-7 breast cancer cells comparing the activities of preformed and in situ coronas showed different uptake behaviors, suggesting the role of protein corona formation in promoting the interaction between the SPIONs and the cells. The results obtained here provide the essential information for further development of the potential strategy to reduce or stimulate immune response in vivo to increase therapeutic applications of both C-SPIONs and Rf-SPIONs.

Quantitative comparison of the protein corona of nanoparticles with different matrices

Nanoparticles (NPs) are paving the way for improved treatments for difficult to treat diseases diseases; however, much is unknown about their fate in the body. One important factor is the interaction between NPs and blood proteins leading to the formation known as the “protein corona” (PC). The PC, consisting of the Hard (HC) and Soft Corona (SC), varies greatly based on the NP composition, size, and surface properties. This highlights the need for specific studies to differentiate the PC formation for each individual NP system. This work focused on comparing the HC and SC of three NPs with different matrix compositions: a) polymeric NPs based on poly(lactic-co-glycolic) acid (PLGA), b) hybrid NPs consisting of PLGA and Cholesterol, and c) lipidic NPs made only of Cholesterol. NPs were formulated and characterized for their physico-chemical characteristics and composition, and then were incubated in human plasma. In-depth purification, identification, and statistical analysis were then performed to identify the HC and SC components. Finally, similar investigations demonstrated whether the presence of a targeting ligand on the NP surface would affect the PC makeup. These results highlighted the different PC fingerprints of these NPs, which will be critical to better understand the biological influences of the PC and improve future NP designs.

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NPs with different matrices were formulated: PLGA, Cholesterol, or mixed PLGA-Chol hybrids.

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The hard and soft corona of each formulation was quantified and compared.

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The PC seems to be more strongly affected by the polymer rather than the lipid in mixed NPs.

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The soft corona depends more on the hard corona composition than on the matrix.

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Surface modification with a targeting ligand did not influence PC composition.

Anti-EGFR Targeted Multifunctional I-131 Radio-Nanotherapeutic for Treating Osteosarcoma: In Vitro 3D Tumor Spheroid Model

The systemic delivery of doxorubicin (DOX) to treat osteosarcoma requires an adequate drug concentration to be effective, but in doing so, it raises the risk of increasing organ off-target toxicity and developing drug resistance. Herein, this study reveals a multiple therapeutic nanocarrier delivery platform that overcomes off-target toxicity by providing good specificity and imparting enhanced tumor penetration in a three-dimensional (3D) human MG-63 spheroid model. By synthesizing PEG-PLGA nanoparticles by the double emulsion method, encapsulating DOX and Na131I in the inner core, and conjugating with an epidermal growth factor receptor (EGFR) antibody, it is intended to specifically target human MG-63 cells. The nanocarrier is biocompatible with blood and has good stability characteristics. Na131I encapsulation efficiency was >96%, and radiochemical purity was >96% over 96 h. A DOX encapsulation efficacy of ~80% was achieved, with a drug loading efficiency of ~3%, and a sustained DOX release over 5 days. The nanocarrier EGFR antibody achieved a ~80-fold greater targeting efficacy to MG-63 cells (EGFR+) than fibroblast cells (EGFR−). The targeted multiple therapeutic DIE-NPs have a higher penetration and uptake of Na131I to the 3D model and a ~3-fold higher cytotoxicity than the DOX monotherapy (D-NPs). The co-administration of DOX and Na131I (DIE-NPs) disrupts DNA repair and generates free radicals resulting in DNA damage, triggering the activation of apoptosis pathways. This leads to inhibition of MG-63 cell proliferation and promotes cell cycle arrest in the G0/G1 phase. Furthermore, the PEGylated anti-EGFR functionalized DIE-NPs were found to be biocompatible with red blood cells and to have no adverse effects. This anti-EGFR targeted multifunctional I-131 radio-nanotherapeutic signifies a customizable specific targeted treatment for osteosarcoma.

Synovial fluid profile dictates nanoparticle uptake into cartilage - implications of the protein corona for novel arthritis treatments

OBJECTIVE

Drug delivery strategies for joint diseases need to overcome the negatively charged cartilage matrix. Previous studies have extensively investigated particle approaches to increase uptake efficiency by harnessing the anionic charge of the cartilage but have neglected to address potential interactions with the protein-rich biological environment of the joint space. We aimed to evaluate the effects of hard protein coronas derived from osteoarthritis (OA) and rheumatoid arthritis (RA) patient synovial fluids as well as the commonly used fetal calf serum (FCS) on nanoparticle (NP) uptake into tissues and cells.

METHODS

We developed a NP panel with varying PEGylation and incubated them with synovial fluid from either OA, RA patients or FCS. We evaluated the effects of the formed NP-biocorona complex uptake into the porcine articular cartilage explants, chondrocytes and monocyte cell lines and primary patient FLS cells. Proteins composing hard biocoronas were identified using a quantitative proteomics approach.

RESULTS

Formed biocoronas majorly impacted NP uptake into cartilage tissue and dictated their uptake in chondrocytes and monocytes. The most suitable NP for potential OA applications was identified. A variety of proteins that were found on all NPs, irrespective of surface modifications. NP-, and protein-specific differences were also observed between the groups, and candidate proteins were identified that could account for the observed differences.

CONCLUSIONS

This study demonstrates the impact of protein coronas from OA and RA patient synovial fluids on NP uptake into cartilage, emphasizing the importance of biological microenvironment considerations for successful translation of drug delivery vehicles into clinics.

The effects of protein corona on in vivo fate of nanocarriers

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

Rosmarinic Acid-Loaded Polymeric Nanoparticles Prepared by Low-Energy Nano-Emulsion Templating: Formulation, Biophysical Characterization, and In Vitro Studies

Rosmarinic acid (RA), a caffeic acid derivative, has been loaded in polymeric nanoparticles made up of poly(lactic-co-glycolic acid) (PLGA) through a nano-emulsion templating process using the phase-inversion composition (PIC) method at room temperature. The obtained RA-loaded nanoparticles (NPs) were colloidally stable exhibiting average diameters in the range of 70–100 nm. RA was entrapped within the PLGA polymeric network with high encapsulation efficiencies and nanoparticles were able to release RA in a rate-controlled manner. A first-order equation model fitted our experimental data and confirmed the prevalence of diffusion mechanisms. Protein corona formation on the surface of NPs was assessed upon incubation with serum proteins. Protein adsorption induced an increase in the hydrodynamic diameter and a slight shift towards more negative surface charges of the NPs. The radical scavenging activity of RA-loaded NPs was also studied using the DPPH·assay and showed a dose–response relationship between the NPs concentration and DPPH inhibition. Finally, RA-loaded NPs did not affect the cellular proliferation of the human neuroblastoma SH-SY5Y cell line and promoted efficient cellular uptake. These results are promising for expanding the use of O/W nano-emulsions in biomedical applications.

Bridging Size and Charge Effects of Mesoporous Silica Nanoparticles for Crossing the Blood–Brain Barrier

The blood–brain barrier (BBB) is a highly selective cellular barrier that tightly controls the microenvironment of the central nervous system to restrict the passage of substances, which is a primary challenge in delivering therapeutic drugs to treat brain diseases. This study aimed to develop simple surface modifications of mesoporous silica nanoparticles (MSNs) without external stimuli or receptor protein conjugation, which exhibited a critical surface charge and size allowing them to cross the BBB. A series of MSNs with various charges and two different sizes of 50 and 200 nm were synthesized, which showed a uniform mesoporous structure with various surface zeta potentials ranging from +42.3 to −51.6 mV. Confocal microscopic results showed that 50 nm of strongly negatively charged N4-RMSN₅₀@PEG/THPMP (∼−40 mV) could be significantly observed outside blood vessels of the brain in Tg(zfli1:EGFP) transgenic zebrafish embryos superior to the other negatively charged MSNs. However, very few positively charged MSNs were found in the brain, indicating that negatively charged MSNs could successfully penetrate the BBB. The data were confirmed by high-resolution images of 3D deconvoluted confocal microscopy and two-photon microscopy and zebrafish brain tissue sections. In addition, while increasing the size to 200 nm but maintaining the similar negative charge (∼40 mV), MSNs could not be detected in the brain of zebrafish, suggesting that transport across the BBB based on MSNs occurred in charge- and size-dependent manners. No obvious cytotoxicity was observed in the CTX-TNA2 astrocyte cell line and U87-MG glioma cell line treated with MSNs. After doxorubicin (Dox) loading, N4-RMSN₅₀@PEG/THPMP/Dox enabled drug delivery and pH-responsive release. The toxicity assay showed that N4-RMSN₅₀@PEG/THPMP could reduce Dox release, resulting in the increase of the survival rate in zebrafish. Flow cytometry demonstrated N4-RMSN₅₀@PEG/THPMP had few cellular uptakes. Protein corona analysis revealed three transporter proteins, such as afamin, apolipoprotein E, and basigin, could contribute to BBB penetration, validating the possible mechanism of N4-RMSN₅₀@PEG/THPMP crossing the BBB. With this simple approach, MSNs with critical negative charge and size could overcome the BBB-limiting characteristics of therapeutic drug molecules; furthermore, their use may also cause drug sustained-release in the brain, decreasing peripheral toxicity.

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

Nanoparticles (NPs) have been demonstrated 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 NP surface, 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 surface 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 discuss 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 are 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.

Untangling Mucosal Drug Delivery: Engineering, Designing, and Testing Nanoparticles to Overcome the Mucus Barrier

Mucus is a complex viscoelastic gel and acts as a barrier covering much of the soft tissue in the human body. High vascularization and accessibility have motivated drug delivery to various mucosal surfaces; however, these benefits are hindered by the mucus layer. To overcome the mucus barrier, many nanomedicines have been developed, with the goal of improving the efficacy and bioavailability of drug payloads. Two major nanoparticle-based strategies have emerged to facilitate mucosal drug delivery, namely, mucoadhesion and mucopenetration. Generally, mucoadhesive nanoparticles promote interactions with mucus for immobilization and sustained drug release, whereas mucopenetrating nanoparticles diffuse through the mucus and enhance drug uptake. The choice of strategy depends on many factors pertaining to the structural and compositional characteristics of the target mucus and mucosa. While there have been promising results in preclinical studies, mucus-nanoparticle interactions remain poorly understood, thus limiting effective clinical translation. This article reviews nanomedicines designed with mucoadhesive or mucopenetrating properties for mucosal delivery, explores the influence of site-dependent physiological variation among mucosal surfaces on efficacy, transport, and bioavailability, and discusses the techniques and models used to investigate mucus-nanoparticle interactions. The effects of non-homeostatic perturbations on protein corona formation, mucus composition, and nanoparticle performance are discussed in the context of mucosal delivery. The complexity of the mucosal barrier necessitates consideration of the interplay between nanoparticle design, tissue-specific differences in mucus structure and composition, and homeostatic or disease-related changes to the mucus barrier to develop effective nanomedicines for mucosal delivery.