Polyethylene glycol backfilling mitigates the negative impact of the protein corona on nanoparticle cell targeting

Centrifugal Field-Flow Fractionation Enables Detection of Slight Aggregation of Nanoparticles That Impacts Their Biomedical Applications

Nanoparticles (NPs) are anticipated to be used for various biomedical applications in which their aggregation has been an important issue. However, concerns regarding slightly aggregated but apparently monodispersed NPs have been difficult to address because of a lack of appropriate evaluation methods. Here, we report centrifugal field-flow fractionation (CF3) as a powerful method for analyzing the slight aggregation of NPs, using antibody-modified gold NPs (Ab-AuNPs) prepared by a conventional protocol with centrifugal purification as a model. While common evaluation methods such as dynamic light scattering cannot detect significant signs of aggregation, CF3 successfully detects distinct peaks of slightly aggregated NPs, including dimers and trimers. Their impact on biological interactions was also demonstrated by a cellular uptake study: slightly aggregated Ab-AuNPs exhibited 1.8 times higher cellular uptake than monodispersed Ab-AuNPs. These results suggest the importance of aggregate evaluation via CF3 as well as the need for careful attention to the bioconjugation procedures for NPs.

Nanocarriers address intracellular barriers for efficient drug delivery, overcoming drug resistance, subcellular targeting and controlled release

The cellular barriers are major bottlenecks for bioactive compounds entering into cells to accomplish their biological functions, which limits their biomedical applications. Nanocarriers have demonstrated high potential and benefits for encapsulating bioactive compounds and efficiently delivering them into target cells by overcoming a cascade of intracellular barriers to achieve desirable therapeutic and diagnostic effects. In this review, we introduce the cellular barriers ahead of drug delivery and nanocarriers, as well as summarize recent advances and strategies of nanocarriers for increasing internalization with cells, promoting intracellular trafficking, overcoming drug resistance, targeting subcellular locations and controlled drug release. Lastly, the future perspectives of nanocarriers for intracellular drug delivery are discussed, which mainly focus on potential challenges and future directions. Our review presents an overview of intracellular drug delivery by nanocarriers, which may encourage the future development of nanocarriers for efficient and precision drug delivery into a wide range of cells and subcellular targets.

Personalized Cancer Nanomedicine: Overcoming Biological Barriers for Intracellular Delivery of Biopharmaceuticals

The success of personalized medicine in oncology relies on using highly effective and precise therapeutic modalities such as small interfering RNA (siRNA) and monoclonal antibodies (mAbs). Unfortunately, the clinical exploitation of these biological drugs has encountered obstacles in overcoming intricate biological barriers. Drug delivery technologies represent a plausible strategy to overcome such barriers, ultimately facilitating the access to intracellular domains. Here, an overview of the current landscape on how nanotechnology has dealt with protein corona phenomena as a first and determinant biological barrier is presented. This continues with the analysis of strategies facilitating access to the tumor, along with conceivable methods for enhanced tumor penetration. As a final step, the cellular barriers that nanocarriers must confront in order for their biological cargo to reach their target are deeply analyzed. This review concludes with a critical analysis and future perspectives of the translational advances in personalized oncological nanomedicine.

Biomolecular Corona of Gold Nanoparticles: The Urgent Need for Strong Roots to Grow Strong Branches

Gold nanoparticles (GNPs) are largely employed in diagnostics/biosensors and are among the most investigated nanomaterials in biology/medicine. However, few GNP-based nanoformulations have received FDA approval to date, and promising in vitro studies have failed to translate to in vivo efficacy. One key factor is that biological fluids contain high concentrations of proteins, lipids, sugars, and metabolites, which can adsorb/interact with the GNP's surface, forming a layer called biomolecular corona (BMC). The BMC can mask prepared functionalities and target moieties, creating new surface chemistry and determining GNPs' biological fate. Here, the current knowledge is summarized on GNP-BMCs, analyzing the factors driving these interactions and the biological consequences. A partial fingerprint of GNP-BMC analyzing common patterns of composition in the literature is extrapolated. However, a red flag is also risen concerning the current lack of data availability and regulated form of knowledge on BMC. Nanomedicine is still in its infancy, and relying on recently developed analytical and informatic tools offers an unprecedented opportunity to make a leap forward. However, a restart through robust shared protocols and data sharing is necessary to obtain "stronger roots". This will create a path to exploiting BMC for human benefit, promoting the clinical translation of biomedical nanotools.

Lipid-mediated protein corona regulation with increased apolipoprotein A-I recruitment for glioma targeting

Protein corona has long been a source of concern, as it might impair the targeting efficacy of targeted drug delivery systems. However, engineered up-regulating the adsorption of certain functional serum proteins could provide nanoparticles with specific targeting drug delivery capacity. Herein, apolipoprotein A-I absorption increased nanoparticles (SPC-PLGA NPs), composed with the Food and Drug Administration approved intravenously injectable soybean phosphatidylcholine (SPC) and poly (DL-lactide-co-glycolide) (PLGA), were fabricated for enhanced glioma targeting. Due to the high affinity of SPC and apolipoprotein A-I, the percentage of apolipoprotein A-I in the protein corona of SPC-PLGA NPs was 2.19-fold higher than that of nanoparticles without SPC, which made SPC-PLGA NPs have superior glioma targeting ability through binding to scavenger receptor class BI on blood-brain barrier and glioma cells both in vitro and in vivo. SPC-PLGA NPs loaded with paclitaxel could effectively reduce glioma invasion and prolong the survival time of glioma-bearing mice. In conclusion, we provided a good example of the direction of achieving targeting drug delivery based on protein corona regulation.

Protein and peptide-based renal targeted drug delivery systems

Renal diseases have become an increasingly concerned public health problem in the world. Kidney-targeted drug delivery has profound transformative potential on increasing renal efficacy and reducing extra-renal toxicity. Protein and peptide-based kidney targeted drug delivery systems have garnered more and more attention due to its controllable synthesis, high biocompatibility and low immunogenicity. At the same time, the targeting methods based on protein/peptide are also abundant, including passive renal targeting based on macromolecular protein and active targeting mediated by renal targeting peptide. Here, we review the application and the drug loading strategy of different proteins or peptides in targeted drug delivery, including the ferritin family, albumin, low molecular weight protein (LMWP), different peptide sequence and antibodies. In addition, we summarized the factors influencing passive and active targeting in drug delivery system, the main receptors related to active targeting in different kidney diseases, and a variety of nano forms of proteins based on the controllable synthesis of proteins.

New Sight of Renal Toxicity Caused by UV-Aged Polystyrene Nanoplastics: Induced Ferroptosis via Adsorption of Transferrin

Secondary nanoplastics (NPs) caused by degradation and aging due to environmental factors are the main source of human exposure, and alterations in the physicochemical and biological properties of NPs induced by environmental factors cannot be overlooked. In this study, pristine polystyrene (PS) NPs to obtain ultraviolet (UV)-aged PS NPs (aPS NPs) as secondary NPs is artificially aged. In a mouse oral exposure model, the nephrotoxicity of PS NPs and aPS NPs is compared, and the results showed that aPS NPs exposure induced more serious destruction of kidney tissue structure and function, along with characteristic changes in ferroptosis. Subsequent in vitro experiments revealed that aPS NPs-induced cell death in human renal tubular epithelial cells involved ferroptosis, which is supported by the use of ferrostatin-1, a ferroptosis inhibitor. Notably, it is discovered that aPS NPs can enhance the binding of serum transferrin (TF) to its receptor on the cell membrane by forming an aPS-TF complex, leading to an increase in intracellular Fe2+ and then exacerbation of oxidative stress and lipid peroxidation, which render cells more sensitive to ferroptosis. These findings indicated that UV irradiation can alter the physicochemical and biological properties of NPs, enhancing their kidney biological toxicity risk by inducing ferroptosis.

Antifouling modification for high-performance isolation of circulating tumor cells

Circulating tumor cells (CTCs), which shed from solid tumor tissue into blood circulatory system, have attracted wide attention as a biomarker in the early diagnosis and prognosis of cancer. Given their potential significance in clinics, many platforms have been developed to separate CTCs. However, the high-performance isolation of CTCs remains significant challenges including achieving the sensitivity and specificity necessary due to their extreme rarity and severe biofouling in blood, such as billions of background cells and various proteins. With the advancement of CTCs detection technologies in recent years, the highly efficient and highly specific detection platforms for CTCs have gradually been developed, resulting in improving CTC capture efficiency, purity and sensitivity. In this review, we systematically describe the current strategies with surface modifications by utilizing the antifouling property of polymer, peptide, protein and cell membrane for high-performance enrichment of CTCs. To wrap up, we discuss the substantial challenges facing by current technologies and the potential directions for future research and development.

Poly(ethyl ethylene phosphate): Overcoming the "Polyethylene Glycol Dilemma" for Cancer Immunotherapy and mRNA Vaccination

Polyethylene glycol conjugation (PEGylation) is the most successful strategy to promote the stability, pharmacokinetics, and efficacy of therapeutics; however, anti-PEG antibodies induced by repeated treatments raise serious concerns about the future of PEGylated therapeutics. In order to solve the "PEG dilemma", polymers with excellent water solubility and biocompatibility are urgently desired to attenuate the generation of anti-PEG antibodies. Here, poly(ethyl ethylene phosphate) (PEEP) with excellent degradability and stealth effects is used as an alternative to PEG to overcome the "PEG dilemma". PEEPylated liposomes exhibit lower immunogenicity and generate negligible anti-PEEP antibodies (IgM and IgG) after repeated treatments. In vivo studies confirm that PEEPylated liposomes loaded with oxaliplatin (PEEPlipo@OxPt) show better pharmacokinetics compared to PEGlipo@OxPt, and they exhibit potent antitumor performances, which can be further promoted with checkpoint blockade immunotherapy. In addition, PEEPylated lipid nanoparticle is also used to develop an mRNA vaccine with the ability to evoke a potent antigen-specific T cell response and achieve excellent antitumor efficacy. PEEP shows promising potentials in the development of next-generation nanomedicines and vaccines with higher safety and efficacy.

Radiosynthesis of Stable 198Au-Nanoparticles by Neutron Activation of αvβ3-Specific AuNPs for Therapy of Tumor Angiogenesis

This paper reports on the development of stable tumor-specific gold nanoparticles (AuNPs) activated by neutron irradiation as a therapeutic option for the treatment of cancer with high tumor angiogenesis. The AuNPs were designed with different mono- or dithiol-ligands and decorated with different amounts of Arg-Gly-Asp (RGD) peptides as a tumor-targeting vector for αvβ3 integrin, which is overexpressed in tissues with high tumor angiogenesis. The AuNPs were evaluated for avidity in vitro and showed favorable properties with respect to tumor cell accumulation. Furthermore, the therapeutic properties of the [198Au]AuNPs were evaluated in vitro on U87MG cells in terms of cell survival, suggesting that these [198Au]AuNPs are a useful basis for future therapeutic concepts.

Cancer chemotherapy resistance: Mechanisms and recent breakthrough in targeted drug delivery

Conventional chemotherapy, one of the most widely used cancer treatment methods, has serious side effects, and usually results in cancer treatment failure. Drug resistance is one of the primary reasons for this failure. The most significant drawbacks of systemic chemotherapy are rapid clearance from the circulation, the drug's low concentration in the tumor site, and considerable adverse effects outside the tumor. Several ways have been developed to boost neoplasm treatment efficacy and overcome medication resistance. In recent years, targeted drug delivery has become an essential therapeutic application. As more mechanisms of tumor treatment resistance are discovered, nanoparticles (NPs) are designed to target these pathways. Therefore, understanding the limitations and challenges of this technology is critical for nanocarrier evaluation. Nano-drugs have been increasingly employed in medicine, incorporating therapeutic applications for more precise and effective tumor diagnosis, therapy, and targeting. Many benefits of NP-based drug delivery systems in cancer treatment have been proven, including good pharmacokinetics, tumor cell-specific targeting, decreased side effects, and lessened drug resistance. As more mechanisms of tumor treatment resistance are discovered, NPs are designed to target these pathways. At the moment, this innovative technology has the potential to bring fresh insights into cancer therapy. Therefore, understanding the limitations and challenges of this technology is critical for nanocarrier evaluation.

pH-Responsive Upconversion Mesoporous Silica Nanospheres for Combined Multimodal Diagnostic Imaging and Targeted Photodynamic and Photothermal Cancer Therapy

Photodynamic therapy (PDT) and photothermal therapy (PTT) have gained considerable attention as potential alternatives to conventional cancer treatments. However, these approaches remain limited by low solubility, poor stability, and inefficient targeting of many common photosensitizers (PSs) and photothermal agents (PTAs). To overcome the aforementioned limitations, we engineered biocompatible and biodegradable tumor-targeted upconversion nanospheres with imaging capabilities. The multifunctional nanospheres consist of a sodium yttrium fluoride core doped with lanthanides (ytterbium, erbium, and gadolinium) and the PTA bismuth selenide (NaYF4:Yb/Er/Gd,Bi2Se3) enveloped in a mesoporous silica shell that encapsulates a PS, chlorin e6 (Ce6), within its pores. NaYF4:Yb/Er converts deeply penetrating near-infrared (NIR) light to visible light, which excites Ce6 to generate cytotoxic reactive oxygen species (ROS), while Bi2Se3 efficiently converts absorbed NIR light to heat. Additionally, Gd enables magnetic resonance imaging of the nanospheres. The mesoporous silica shell is coated with DPPC/cholesterol/DSPE-PEG to retain the encapsulated Ce6 and prevent serum protein adsorption and macrophage recognition that hinder tumor targeting. Finally, the coat is conjugated to the acidity-triggered rational membrane (ATRAM) peptide, which promotes specific and efficient internalization into malignant cells in the mildly acidic microenvironment of tumors. The nanospheres facilitated tumor magnetic resonance and thermal and fluorescence imaging and exhibited potent NIR laser light-induced anticancer effects in vitro and in vivo via combined ROS production and localized hyperthermia, with negligible toxicity to healthy tissue, hence markedly extending survival. Our results demonstrate that the ATRAM-functionalized, lipid/PEG-coated upconversion mesoporous silica nanospheres (ALUMSNs) offer multimodal diagnostic imaging and targeted combinatorial cancer therapy.

Theranostic Lipid Nanoparticles for Renal Cell Carcinoma

Renal cell carcinoma (RCC) is a common urological malignancy and represents a leading threat to healthcare. Recent years have seen a series of progresses in the early diagnosis and management of RCC. Theranostic lipid nanoparticles (LNPs) are increasingly becoming one of the focuses in this field, because of their suitability for tumor targeting and multimodal therapy. LNPs can be precisely fabricated with desirable chemical compositions and biomedical properties, which closely match the physiological characteristics and clinical needs of RCC. Herein, a comprehensive review of theranostic LNPs is presented, emphasizing the generic tool nature of LNPs in developing advanced micro-nano biomaterials. It begins with a brief overview of the compositions and formation mechanism of LNPs, followed with an introduction to kidney-targeting approaches, such as passive, active, and stimulus responsive targeting. With examples provided, a series of modification strategies for enhancing the tumor targeting and functionality of LNPs are discussed. Thereafter, research advances on applications of these LNPs for RCC including bioimaging, liquid biopsy, drug delivery, physical therapy, and gene therapy are summarized and discussed from an interdisciplinary perspective. The final part highlights the milestone achievements of translation medicine, current challenges as well as future development directions of LNPs for the diagnosis and treatment of RCC.

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.

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

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

Low-dose albumin-coated gold nanorods induce intercellular gaps on vascular endothelium by causing the contraction of cytoskeletal actin

Cytotoxicity of nanoparticles, typically evaluated by biochemical-based assays, often overlook the cellular biophysical properties such as cell morphology and cytoskeletal actin, which could serve as more sensitive indicators for cytotoxicity. Here, we demonstrate that low-dose albumin-coated gold nanorods (HSA@AuNRs), although being considered noncytotoxic in multiple biochemical assays, can induce intercellular gaps and enhance the paracellular permeability between human aortic endothelial cells (HAECs). The formation of intercellular gaps can be attributed to the changed cell morphology and cytoskeletal actin structures, as validated at the monolayer and single cell levels using fluorescence staining, atomic force microscopy, and super-resolution imaging. Molecular mechanistic study shows the caveolae-mediated endocytosis of HSA@AuNRs induces the calcium influx and activates actomyosin contraction in HAECs. Considering the important roles of endothelial integrity/dysfunction in various physiological/pathological conditions, this work suggests a potential adverse effect of albumin-coated gold nanorods on the cardiovascular system. On the other hand, this work also offers a feasible way to modulate the endothelial permeability, thus promoting drug and nanoparticle delivery across the endothelium.

Functionalized zein nanoparticles targeting neonatal Fc receptor to enhance lung absorption of peptides

Peptides have a distinguished therapeutic potential for several chronic conditions, and more than 80 peptides exist in the global market. However, most of these marketed peptide drugs are currently delivered intravenously or subcutaneously due to their fast degradation and limited absorption through non-invasive routes. The pulmonary route is favored as a non-invasive route. Neonatal Fc receptor (FcRn) is expressed in adult human lungs and has a role in enhancing the pulmonary absorption of monoclonal antibodies. In this work, we developed and characterized candidate protein delivery systems for the pulmonary administration of peptides. The prepared bare and loaded zein nanoparticles (ZNPs), targeted, physically, and covalently PEGylated ZNPs showed hydrodynamic diameters between 137 and 155 nm and a narrow distribution index. Insulin, which was used as a protein model, showed an association efficiency of 72%, while the FcRn-targeted peptide conjugation efficiency was approximately 68%. The physically adsorbed poloxamer 407 on insulin-loaded ZNPs showed slower and controlled insulin release. The in vitro cell culture model consists of the NCI-H441 epithelial cell line, which confirmed its expression of the targeted receptor, FcRn. The safety of ZNPs was verified after incubation with both cell lines of the in vitro pulmonary model, namely NCI-H441 and HPMEC-ST1.6R, for 24 h. It was observed that targeted ZNPs enhanced insulin permeability by showing a higher apparent permeation coefficient than non-targeted ZNPs. Overall, both targeted PEGylated ZNPs showed to be suitable peptide carriers and adequately fit the demands of delivery systems designed for pulmonary administration.

pH-responsive upconversion mesoporous silica nanospheres for combined multimodal diagnostic imaging and targeted photodynamic and photothermal cancer therapy

Photodynamic therapy (PDT) and photothermal therapy (PTT) have garnered considerable interest as non-invasive cancer treatment modalities. However, these approaches remain limited by low solubility, poor stability and inefficient targeting of many common photosensitizers (PSs) and photothermal agents (PTAs). To overcome these limitations, we have designed biocompatible and biodegradable tumor-targeted upconversion nanospheres with imaging capabilities. The multifunctional nanospheres consist of a sodium yttrium fluoride core doped with lanthanides (ytterbium, erbium and gadolinium) and bismuth selenide (NaYF 4 :Yb/Er/Gd,Bi 2 Se 3 ) within a mesoporous silica shell that encapsulates a PS, Chlorin e6 (Ce6), in its pores. NaYF 4 :Yb/Er converts deeply penetrating near-infrared (NIR) light to visible light, which excites the Ce6 to generate cytotoxic reactive oxygen species (ROS), while the PTA Bi 2 Se 3 efficiently converts absorbed NIR light to heat. Additionally, Gd enables magnetic resonance imaging (MRI) of the nanospheres. The mesoporous silica shell is coated with lipid/polyethylene glycol (DPPC/cholesterol/DSPE-PEG) to ensure retention of the encapsulated Ce6 and minimize interactions with serum proteins and macrophages that impede tumor targeting. Finally, the coat is functionalized with the acidity-triggered rational membrane (ATRAM) peptide, which promotes specific and efficient internalization into cancer cells within the mildly acidic tumor microenvironment. Following uptake by cancer cells in vitro , NIR laser irradiation of the nanospheres caused substantial cytotoxicity due to ROS production and hyperthermia. The nanospheres facilitated tumor MRI and thermal imaging, and exhibited potent NIR laser light-induced antitumor effects in vivo via combined PDT and PTT, with no observable toxicity to healthy tissue, thereby substantially prolonging survival. Our results demonstrate that the ATRAM-functionalized, lipid/PEG-coated upconversion mesoporous silica nanospheres (ALUMSNs) offer multimodal diagnostic imaging and targeted combinatorial cancer therapy.

Carboxyl PEGylation of magnetic nanoparticles as antithrombotic and thrombolytic agents by calcium binding

Known to be biocompatible and hemocompatible, polyethylene glycol (PEG) has been widely used as anti-fouling coating of biomaterials. Nanoparticles coated with functionalized PEG were also investigated for their nano-cell interactions, but seldomly on the coagulation system, especially with platelets. Both experiments and molecular dynamic simulations indicate that terminal carboxylation of PEG promotes its binding with calcium, especially in the ionized form, which makes it potential anticoagulants. Further, the carboxyl PEGylated magnetic nanoparticle (HOOC-PEG₂₀₀₀-MNP) exhibits significantly increased anticoagulant and antiplatelet properties, by entering the open canalicular system (OCS) of human platelets and binding with the cytoplasmic calcium ions. HOOC-PEG₂₀₀₀-MNP also acts as effective thrombolytic agents in dissolving mature blood clots under oscillating magnetic field both in vitro and in vivo. Therefore, the carboxyl PEGylated magnetic nanoparticles are prototype agents for antithrombotic and thrombolytic therapies and provide a versatile platform for targeted and effective treatments of acute cardiovascular diseases.

Dual-Drug Delivery by Anisotropic and Uniform Hybrid Nanostructures: A Comparative Study of the Function and Substrate-Drug Interaction Properties

By utilizing nanoparticles to upload and interact with several pharmaceuticals in varying methods, the primary obstacles associated with loading two or more medications or cargos with different characteristics may be addressed. Therefore, it is feasible to evaluate the benefits provided by co-delivery systems utilizing nanoparticles by investigating the properties and functions of the commonly used structures, such as multi- or simultaneous-stage controlled release, synergic effect, enhanced targetability, and internalization. However, due to the unique surface or core features of each hybrid design, the eventual drug-carrier interactions, release, and penetration processes may vary. Our review article focused on the drug's loading, binding interactions, release, physiochemical, and surface functionalization features, as well as the varying internalization and cytotoxicity of each structure that may aid in the selection of an appropriate design. This was achieved by comparing the actions of uniform-surfaced hybrid particles (such as core-shell particles) to those of anisotropic, asymmetrical hybrid particles (such as Janus, multicompartment, or patchy particles). Information is provided on the use of homogeneous or heterogeneous particles with specified characteristics for the simultaneous delivery of various cargos, possibly enhancing the efficacy of treatment techniques for illnesses such as cancer.

Surface design of nanocarriers: Key to more efficient oral drug delivery systems

As nanocarriers (NCs) can improve the solubility of drugs, prevent their degradation by gastrointestinal (GI) enzymes and promote their transport across the mucus gel layer and absorption membrane, the oral bioavailability of these drugs can be substantially enhanced. All these properties of NCs including self-emulsifying drug delivery systems (SEDDS), solid lipid nanoparticles (SLNs), nanostructured lipid carriers (NLCs), liposomes, polymeric nanoparticles, inorganic nanoparticles and polymeric micelles depend mainly on their surface chemistry. In particular, interaction with food, digestive enzymes, bile salts and electrolytes, diffusion behaviour across the mucus gel layer and fate on the absorption membrane are determined by their surface. Bioinert surfaces limiting interactions with gastrointestinal fluid and content as well as with mucus, adhesive surfaces providing an intimate contact with the GI mucosa and absorption enhancing surfaces can be designed. Furthermore, charge converting surfaces shifting their zeta potential from negative to positive directly at the absorption membrane and surfaces providing a targeted drug release are advantageous. In addition to these passive surfaces, even active surfaces cleaving mucus glycoproteins on their way through the mucus gel layer can be created. Within this review, we provide an overview on these different surfaces and discuss their impact on the performance of NCs in the GI tract.

Gold Complexes in Anticancer Therapy: From New Design Principles to Particle-Based Delivery Systems

The discovery of the medicinal properties of gold complexes has fuelled the design and synthesis of new anticancer metallodrugs, which have received special attention due to their unique modes of action. Current research in the development of gold compounds with therapeutic properties is predominantly focused on the molecular design of drug leads with superior pharmacological activities, e.g., by introducing targeting features. Moreover, intensive research aims at improving the physicochemical properties of gold compounds, such as chemical stability and solubility in the physiological environment. In this regard, the encapsulation of gold compounds in nanocarriers or their chemical grafting onto targeted delivery vectors could lead to new nanomedicines that eventually reach clinical applications. Herein, we provide an overview of the state-of-the-art progress of gold anticancer compounds, andmore importantly we thoroughly revise the development of nanoparticle-based delivery systems for gold chemotherapeutics.

Mechanobiological modulation of blood-brain barrier permeability by laser stimulation of endothelial-targeted nanoparticles

The blood-brain barrier (BBB) maintains an optimal environment for brain homeostasis but excludes most therapeutics from entering the brain. Strategies that reversibly increase BBB permeability are essential for treating brain diseases and are the focus of significant preclinical and translational interest. Picosecond laser excitation of tight junction-targeted gold nanoparticles (AuNPs) generates a nanoscale mechanical perturbation and induces a graded and reversible increase in BBB permeability (OptoBBB). Here we advanced this technique by showing that targeting endothelial glycoproteins leads to >10-fold higher targeting efficiency than targeting tight junctions both in vitro and in vivo. With both tight-junction and glycoprotein targeting, we demonstrate that OptoBBB is associated with a transient elevation and propagation of Ca2+, actin polymerization, and phosphorylation of ERK1/2 (extracellular signal-regulated protein kinase). These collectively activate the cytoskeleton resulting in increased paracellular permeability. The Ca2+ response involves internal Ca2+ depletion and Ca2+ influx with contributions from mechanosensitive ion channels (TRPV4, Piezo1). We provide insight into how the excitation of tight junction protein (JAM-A)-targeted and endothelial (glycocalyx)-targeted AuNPs leads to similar mechanobiological modulation of BBB permeability while targeting the glycocalyx significantly improves the nanoparticle accumulation in the brain. The results will be critical for guiding the future development of this technology for brain disease treatment.

Reagents for Mass Cytometry

Mass cytometry (cytometry by time-of-flight detection [CyTOF]) is a bioanalytical technique that enables the identification and quantification of diverse features of cellular systems with single-cell resolution. In suspension mass cytometry, cells are stained with stable heavy-atom isotope-tagged reagents, and then the cells are nebulized into an inductively coupled plasma time-of-flight mass spectrometry (ICP-TOF-MS) instrument. In imaging mass cytometry, a pulsed laser is used to ablate ca. 1 μm² spots of a tissue section. The plume is then transferred to the CyTOF, generating an image of biomarker expression. Similar measurements are possible with multiplexed ion bean imaging (MIBI). The unit mass resolution of the ICP-TOF-MS detector allows for multiparametric analysis of (in principle) up to 130 different parameters. Currently available reagents, however, allow simultaneous measurement of up to 50 biomarkers. As new reagents are developed, the scope of information that can be obtained by mass cytometry continues to increase, particularly due to the development of new small molecule reagents which enable monitoring of active biochemistry at the cellular level. This review summarizes the history and current state of mass cytometry reagent development and elaborates on areas where there is a need for new reagents. Additionally, this review provides guidelines on how new reagents should be tested and how the data should be presented to make them most meaningful to the mass cytometry user community.

Enhanced Cytotoxic Activity of PEGylated Curcumin Derivatives: Synthesis, Structure-Activity Evaluation, and Biological Activity

Curcumin has been modified in various ways to broaden its application in medicine and address its limitations. In this study, we present a series of curcumin-based derivatives obtained by replacing the hydroxy groups in the feruloyl moiety with polyethylene glycol (PEG) chains and the addition of the BF₂ moiety to the carbonyl groups. Tested compounds were screened for their cytotoxic activity toward two bladder cancer cell lines, 5637 and SCaBER, and a noncancerous cell line derived from lung fibroblasts (MRC-5). Cell viability was analyzed under normoxic and hypoxic conditions (1% oxygen). Structure-activity relationships (SARs) are discussed, and curcumin derivatives equipped within feruloyl moieties with 3-methoxy and 4-{2-[2-(2-methoxyethoxy)ethoxy]ethoxy} substituents (5) were selected for further analysis. Compound 5 did not affect the viability of MRC-5 cells and exerted a stronger cytotoxic effect under hypoxic conditions. However, the flow cytometry studies showed that PEGylation did not improve cellular uptake. Another observation was that the lack of serum proteins limits the intracellular uptake of curcumin derivative 5. The preliminary mechanism of action studies indicated that compound 5 under hypoxic conditions induced G2/M arrest in a dose-dependent manner and increased the expression of stress-related proteins such as p21/CIP1, phosphorylated HSP27, ADAMTS-1, and phosphorylated JNK. In summary, the results of the studies indicated that PEGylated curcumin is a more potent compound against bladder cancer cell lines than the parent compound, and derivative 5 is worthy of further investigation to clarify its mechanism of anticancer action under hypoxic conditions.

Directing the Way-Receptor and Chemical Targeting Strategies for Nucleic Acid Delivery

Nucleic acid therapeutics have shown great potential for the treatment of numerous diseases, such as genetic disorders, cancer and infections. Moreover, they have been successfully used as vaccines during the COVID-19 pandemic. In order to unfold full therapeutical potential, these nano agents have to overcome several barriers. Therefore, directed transport to specific tissues and cell types remains a central challenge to receive carrier systems with enhanced efficiency and desired biodistribution profiles. Active targeting strategies include receptor-targeting, mediating cellular uptake based on ligand-receptor interactions, and chemical targeting, enabling cell-specific delivery as a consequence of chemically and structurally modified carriers. With a focus on synthetic delivery systems including polyplexes, lipid-based systems such as lipoplexes and lipid nanoparticles, and direct conjugates optimized for various types of nucleic acids (DNA, mRNA, siRNA, miRNA, oligonucleotides), we highlight recent achievements, exemplified by several nucleic acid drugs on the market, and discuss challenges for targeted delivery to different organs such as brain, eye, liver, lung, spleen and muscle in vivo.

Oridonin inhibits inflammation of epithelial cells via dual-targeting of CD31 Keap1 to ameliorate acute lung injury

Introdcution

Acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) are major causes of COVID-19 mortality. However, drug delivery to lung tissues is impeded by endothelial cell barriers, limiting the efficacy of existing treatments. A prompt and aggressive treatment strategy is therefore necessary.

Methods

We assessed the ability of anti-CD31-ORI-NPs to penetrate endothelial cell barriers and specifically accumulate in lung tissues using an animal model. We also compared the efficacy of anti-CD31-ORI-NPs to that of free oridonin in ameliorating acute lung injury and evaluated the cytotoxicity of both treatments on endothelial cells.

Results

Compared to free ORI, the amount of anti-CD31-ORI-NPs accumulated in lung tissues increase at least three times. Accordingly, anti-CD31-ORI-NPs improve the efficacy three times on suppressing IL-6 and TNF-a secretion, ROS production, eventually ameliorating acute lung injury in animal model. Importantly, anti-CD31-ORI-NPs significantly decrease the cytotoxicity at least two times than free oridonin on endothelial cells.

Discussion

Our results from this study will not only offer a novel therapeutic strategy with high efficacy and low toxicity, but also provide the rational design of nanomaterials of a potential drug for acute lung injury therapy.

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

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

The engineering challenges and opportunities when designing potent ionizable materials for the delivery of ribonucleic acids

INTRODUCTION

Ionizable lipids are critical components in lipid nanoparticles. These molecules sequester nucleic acids for delivery to cells. However, to build more efficacious delivery molecules, the field must continue to broaden structure-function studies for greater insight. While nucleic acid-binding efficiency, degradability and nanoparticle stability are vitally important, this review offers perspective on additional factors that must be addressed to improve delivery efficiency.

AREAS COVERED

We discuss how administration route, cellular heterogeneity, uptake pathway, endosomal escape timing, age, sex, and threshold effects can change depending on the type of LNP ionizable lipid.

EXPERT OPINION

Ionizable lipid structure-function studies often focus on the efficiency of RNA utilization and biodistribution. While these focus areas are critical, they remain high-level observations. As our tools for observation and system interrogation improve, we believe that the field should begin collecting additional data. At the cellular level, this data should include age (dividing or senescent cells), sex and phenotype, cell entry pathway, and endosome type. Additionally, administration route and dose are essential to track. This additional data will allow us to identify and understand heterogeneity in LNP efficacy across patient populations, which will help us provide better ionizable lipid options for different groups.

Toxicokinetics, dose-response, and risk assessment of nanomaterials: Methodology, challenges, and future perspectives

The rapid growth of nanomaterial applications has raised safety concerns for human health. A number of studies have been conducted to assess the toxicokinetics, toxicology, dose-response, and risk assessment of different nanomaterials using in vitro and in vivo animal and human models. However, current studies cannot meet the demand for efficient assessment of toxicokinetics, dose-response relationships, or the toxicological risk arising from the rapidly increasing number of newly synthesized nanomaterials. In this article, we review the methods for conducting toxicokinetics, hazard identification, dose-response, exposure, and risk assessment studies of nanomaterials, identify the knowledge gaps, and discuss the challenges remaining. We provide the rationale behind the appropriate design of nanomaterial plasma toxicokinetic and tissue distribution studies, including caveats on the interpretation and correlation of in vitro and in vivo toxicology studies. The potential of using physiologically based pharmacokinetic (PBPK) models to extrapolate toxicokinetic and toxicity findings from in vitro to in vivo and from animals to humans is discussed, and the knowledge gaps of PBPK modeling for nanomaterials are identified. While challenges still exist, there has been progress in the toxicokinetics, hazard identification, and risk assessment of nanomaterials in the past two decades. Recent advancements in the field are highlighted with relevant examples. We also share latest guidelines as well as our perspectives on future studies needed to characterize the toxicokinetics, toxicity, and dose-response relationship in support of nanomaterial risk assessment. This article is categorized under: Toxicology and Regulatory Issues in Nanomedicine > Toxicology of Nanomaterials Toxicology and Regulatory Issues in Nanomedicine > Regulatory and Policy Issues in Nanomedicine.

Plastic and Placenta: Identification of Polyethylene Glycol (PEG) Compounds in the Human Placenta by HPLC-MS/MS System

The placenta is a crucial interface between the fetus and the maternal environment. It allows for nutrient absorption, thermal regulation, waste elimination, and gas exchange through the mother's blood supply. Furthermore, the placenta determines important adjustments and epigenetic modifications that can change the phenotypic expression of the individual even long after birth. Polyethylene glycol (PEG) is a polyether compound derived from petroleum with many applications, from medicine to industrial manufacturing. In this study, for the first time, an integration of ultra-high-performance liquid chromatography (UHPLC) coupled with mass spectrometry (MS) was used to detect suites of PEG compounds in human placenta samples, collected from 12 placentas, originating from physiological pregnancy. In 10 placentas, we identified fragments of PEG in both chorioamniotic membranes and placental cotyledons, for a total of 36 samples.

Tailored polyethylene glycol grafting on porous nanoparticles for enhanced targeting and intracellular siRNA delivery

Surface functionalization of nanoparticles with polyethylene glycol (PEG) has been widely demonstrated as an anti-opsonization strategy to reduce protein corona formation which is one of the major concerns affecting target receptor recognition. However, excessive surface passivation with PEG can lead to the strong inhibition of cellular uptake and less efficient binding to target receptors, resulting in reduced potential of targeted delivery. To improve specific cell targeting while reducing the nonspecific protein adsorption, a secondary packaging of the nanoparticles with shorter PEG chains, making the targeting ligands densely stretched out for enhanced molecular recognition is demonstrated. Particularly, we report the tailored surface functionalization of the porous nanoparticles that require the stealth shielding onto the open-pore region. This study shows that, in addition to the surface chemistry, the conformation of the PEG layers controls the cellular interaction of nanoparticles. Since the distance between neighboring PEG chains determines the structural conformation of the grafted PEG molecules, tailored PEG combinations can efficiently resist the adsorption of serum proteins onto the pores by transitioning the conformation of the PEG chains, thus significantly enhance the targeting efficiency (>5-fold). The stretched brush PEG conformation with secondary packaging of shorter PEG chains could be a promising anti-opsonization and active targeting strategy for efficient intracellular delivery of nanoparticles.

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

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

Nanoparticle entry into cells; the cell biology weak link

Nanoparticles (NP) are attractive options for the therapeutic delivery of active pharmaceutical drugs, proteins and nucleic acids into cells, tissues and organs. Research into the development and application of NP most often starts with a diverse group of scientists, including chemists, bioengineers and material and pharmaceutical scientists, who design, fabricate and characterize NP in vitro (Stage 1). The next step (Stage 2) generally investigates cell toxicity as well as the processes by which NP bind, are internalized and deliver their cargo to appropriate model tissue culture cells. Subsequently, in Stage 3, selected NP are tested in animal systems, mostly mouse. Whereas the chemistry-based development and analysis in Stage 1 is increasingly sophisticated, the investigations in Stage 2 are not what could be regarded as 'state-of-the-art' for the cell biology field and the quality of research into NP interactions with cells is often sub-standard. In this review we describe our current understanding of the mechanisms by which particles gain entry into mammalian cells via endocytosis. We summarize the most important areas for concern, highlight some of the most common mis-conceptions, and identify areas where NP scientists could engage with trained cell biologists. Our survey of the different mechanisms of uptake into cells makes us suspect that claims for roles for caveolae, as well as macropinocytosis, in NP uptake into cells have been exaggerated, whereas phagocytosis has been under-appreciated.

Redox-labelled electrochemical aptasensors with nanosupported cancer cells

The transfer of redox-labelled bioelectrochemical sensors from proteins to cells is not straightforward because of the cell downward force issue on the surface of the sensors. In this paper, 20-nm-thick nanopillars are introduced to overcome this issue, in a well-controlled manner. We show on both molecular dynamics simulations and experiments that suspending cells a few nanometers above an electrode surface enables redox-labelled tethered DNA aptamer probes to move freely, while remaining at an interaction distance from a target membrane protein, i. e. epithelial cell adhesion molecule (EpCAM), which is typically overexpressed in cancer cells. By this nanopillar configuration, the interaction of aptamer with cancer cells is clearly observable, with 13 cells as the lower limit of detection. Nanoconfinement induced by the gap between the electrode surface and the cell membrane appears to improve the limit of detection and to lower the melting temperature of DNA aptamer hairpins, offering an additional degree of freedom to optimize molecular recognition mechanisms. This novel nanosupported electrochemical DNA cell sensor scheme including Brownian-fluctuating redox species opens new opportunities for the design of all-electrical sensors using redox-labelled probes.

Stimuli-responsive nanoassemblies for targeted delivery against tumor and its microenvironment

Despite the emergence of various cancer treatments, such as surgery, chemotherapy, radiotherapy, and immunotherapy, their use remains restricted owing to their limited tumor elimination efficacy and side effects. The use of nanoassemblies as delivery systems in nanomedicine for tumor diagnosis and therapy is flourishing. These nanoassemblies can be designed to have various shapes, sizes, and surface charges to meet the requirements of different applications. It is crucial for nanoassemblies to have enhanced delivery of payloads while inducing minimal to no toxicity to healthy tissues. In this review, stimuli-responsive nanoassemblies capable of combating the tumor microenvironment (TME) are discussed. First, various TME characteristics, such as hypoxia, oxidoreduction, adenosine triphosphate (ATP) elevation, and acidic TME, are described. Subsequently, the unique characteristics of the vascular and stromal TME are differentiated, and multiple barriers that have to be overcome are discussed. Furthermore, strategies to overcome these barriers for successful drug delivery to the targeted site are reviewed and summarized. In conclusion, the possible challenges and prospects of using these nanoassemblies for tumor-targeted delivery are discussed. This review aims at inspiring researchers to develop stimuli-responsive nanoassemblies for tumor-targeted delivery for clinical applications.

Protein corona: challenges and opportunities for targeted delivery of nanomedicines

INTRODUCTION

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

AREAS COVERED

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

EXPERT OPINION

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

A Dense Layer of Polyethyleneglycol and Zwitterionic Bone Targeting Peptide on the Surface of Stereocomplex Polylactide-Polyethyleneglycol Nanoparticles Improves Shelf-Storage Stability and the Serum Compatibility

The surface properties of nanoparticles (NPs) affect their stability and formation of the protein corona, which influence their targeting abilities. We evaluated these properties using bone (hydroxyapatite; HAP) targeting peptide on tamoxifen (TAM)-loaded stereocomplexformed polylactide-polyethyleneglycol (SC-PLA-PEG) NPs. Octaaspartic acid-octaglycine-cysteine (D8G8C) anionic derivative (Ani. pep.) and octa-aspartic acid-octa lysine-cysteine (D8K8C), a zwitterionic derivative (Zwi. pep.) were conjugated with SC-PLA-PEG NPs as HAP-targeting peptides. The addition of hydrophobic PLA homopolymers increased the surface PEG density on the NPs. Denser PEG chains on NPs decreased their specific surface area, reducing protein adsorption on the NPs and TAM release from NPs. NPs with dense PEG chains and Zwi. pep. showed superior shelf stability and lower protein adsorption than NPs with dense PEG chains and Ani. pep. in murine serum. Furthermore, the HAP-binding ability of NPs with Zwi. pep. was significantly higher than that of NPs with Ani. pep. These results indicate that decreasing the specific surface area and zwitterionization of HAP-targeting peptides on NPs are promising approaches to improve the serum compatibility and stability of NPs.

Controlling the Biological Behaviors of Polymer-Coated Upconverting Nanoparticles by Adjusting the Linker Length of Estrone Ligands

The estrone ligand is used for modifying nanoparticle surfaces to improve their targeting effect on cancer cell lines. However, to date, there is no common agreement on the ideal linker length to be used for the optimum targeting performance. In this study, we aimed to investigate the impact of poly(poly ethylene glycol methyl ether methacrylate) (PPEGMEMA) linker length on the cellular uptake behavior of polymer-coated upconverting nanoparticles (UCNPs). Different triblock terpolymers, poly(poly (ethylene glycol) methyl ether methacrylate)-block-polymethacrylic acid-block-polyethylene glycol methacrylate phosphate (PPEGMEMA_x-b-PMAA_y-b-PEGMP₃: x = 7, 15, 33, and 80; y = 16, 20, 18, and 18), were synthesized with different polymer linker chain lengths between the surface and the targeting ligand by reversible addition-fragmentation chain transfer polymerization. The estrone ligand was attached to the polymer via specific terminal conjugation. The cellular association of polymer-coated UCNPs with linker chain lengths was evaluated in MCF-7 cells by flow cytometry. Our results showed that the bioactivity of ligand modification is dependent on the length of the polymer linker. The shortest polymer PPEGMEMA₇-b-PMAA₁₆-b-PEGMP₃ with estrone at the end of the polymer chain was found to have the best cellular association behavior in the estrogen receptor (ER)α-positive expression cell line MCF-7. Additionally, the anticancer drug doxorubicin•HCl was encapsulated in the nanocarrier to evaluate the 2D and 3D cytotoxicity. The results showed that estrone modification could efficiently improve the cellular uptake in ERα-positive expression cell lines and in 3D spheroid models.

Chemical and Biophysical Signatures of the Protein Corona in Nanomedicine

An inconvenient hurdle in the practice of nanomedicine is the protein corona, a spontaneous collection of biomolecular species by nanoparticles in living systems. The protein corona is dynamic in composition and may entail improved water suspendability and compromised delivery and targeting to the nanoparticles. How much of this nonspecific protein ensemble is determined by the chemistry of the nanoparticle core and its surface functionalization, and how much of this entity is dictated by the biological environments that vary spatiotemporally in vivo? How do we "live with" and exploit the protein corona without significantly sacrificing the efficacy of nanomedicines in diagnosing and curing human diseases? This article discusses the chemical and biophysical signatures of the protein corona and ponders challenges ahead for the field of nanomedicine.

The Promise of Nanotechnology in Personalized Medicine

Both personalized medicine and nanomedicine are new to medical practice. Nanomedicine is an application of the advances of nanotechnology in medicine and is being integrated into diagnostic and therapeutic tools to manage an array of medical conditions. On the other hand, personalized medicine, which is also referred to as precision medicine, is a novel concept that aims to individualize/customize therapeutic management based on the personal attributes of the patient to overcome blanket treatment that is only efficient in a subset of patients, leaving others with either ineffective treatment or treatment that results in significant toxicity. Novel nanomedicines have been employed in the treatment of several diseases, which can be adapted to each patient-specific case according to their genetic profiles. In this review, we discuss both areas and the intersection between the two emerging scientific domains. The review focuses on the current situation in personalized medicine, the advantages that can be offered by nanomedicine to personalized medicine, and the application of nanoconstructs in the diagnosis of genetic variability that can identify the right drug for the right patient. Finally, we touch upon the challenges in both fields towards the translation of nano-personalized medicine.

Nanodelivery of nucleic acids

There is growing need for a safe, efficient, specific and non-pathogenic means for delivery of gene therapy materials. Nanomaterials for nucleic acid delivery offer an unprecedented opportunity to overcome these drawbacks; owing to their tunability with diverse physico-chemical properties, they can readily be functionalized with any type of biomolecules/moieties for selective targeting. Nucleic acid therapeutics such as antisense DNA, mRNA, small interfering RNA (siRNA) or microRNA (miRNA) have been widely explored to modulate DNA or RNA expression Strikingly, gene therapies combined with nanoscale delivery systems have broadened the therapeutic and biomedical applications of these molecules, such as bioanalysis, gene silencing, protein replacement and vaccines. Here, we overview how to design smart nucleic acid delivery methods, which provide functionality and efficacy in the layout of molecular diagnostics and therapeutic systems. It is crucial to outline some of the general design considerations of nucleic acid delivery nanoparticles, their extraordinary properties and the structure-function relationships of these nanomaterials with biological systems and diseased cells and tissues.

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

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

Biotinylated Lipid-Coated NaLnF4 Nanoparticles: Demonstrating the Use of Lanthanide Nanoparticle-Based Reporters in Suspension and Imaging Mass Cytometry

Lanthanide nanoparticles (LnNPs) have the potential to be used as high-sensitivity mass tag reporters in mass cytometry immunoassays. For this application, however, the LnNPs must be made colloidally stable in aqueous buffers, demonstrate minimal non-specific binding to cells, and have functional groups to attach antibodies or other targeting agents. One possible approach to address these requirements is by using lipid coating to modify the surface of the LnNPs. In this work, 39 nm diameter NaYF₄:Yb, Er NPs (LnNPs) were coated with a lipid formulation consisting of egg sphingomyelin, 1,2-dioleoyl-sn-glycero-3-phosphocholine, 1,2-dioleoyl-3-trimethylammonium propane, cholesterol-(polyethylene glycol-600), and 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-[biotinyl(polyethylene glycol)-2000]. The resulting biotinylated lipid-coated LnNPs were characterized by dynamic light scattering to determine the hydrodynamic size and stability in phosphate buffered saline, and the composition of the lipid coatings was quantified by liquid chromatography-tandem mass spectrometry. The specific and non-specific binding of the biotinylated lipid-coated LnNPs to a model system of functionalized polystyrene microbeads were then tested by both suspension and imaging mass cytometry. We found that targeted binding with minimal non-specific binding can be achieved with the lipid-coated LnNPs and that the lipid composition of the coating has an impact on the performance of the LnNPs as mass cytometry reporters. These results additionally establish the importance of quantifying the composition of lipid-coated nanomaterials to optimize them more effectively for their desired application.

Limited Impact of the Protein Corona on the Cellular Uptake of PEGylated Zein Micelles by Melanoma Cancer Cells

The formation of a protein layer “corona” on the nanoparticle surface upon entry into a biological environment was shown to strongly influence the interactions with cells, especially affecting the uptake of nanomedicines. In this work, we present the impact of the protein corona on the uptake of PEGylated zein micelles by cancer cells, macrophages, and dendritic cells. Zein was successfully conjugated with poly(ethylene glycol) (PEG) of varying chain lengths (5K and 10K) and assembled into micelles. Our results demonstrate that PEGylation conferred stealth effects to the zein micelles. The presence of human plasma did not impact the uptake levels of the micelles by melanoma cancer cells, regardless of the PEG chain length used. In contrast, it decreased the uptake by macrophages and dendritic cells. These results therefore make PEGylated zein micelles promising as potential drug delivery systems for cancer therapy.