Protein-Based Nanoparticles as Drug Delivery Systems

New Perspective on Natural Plant Protein-Based Nanocarriers for Bioactive Ingredients Delivery

The health effects of bioactive substances in the human body are affected by several factors, including food processing conditions, storage conditions, light and heat, among others. These factors greatly limit the stability and bioavailability of bioactive substances. These problems can be solved by a novel protein-based nanocarrier technology, which has the excellent potential to enhance solubility, bioavailability, and the controlled release of bioactive substances. In addition, plant protein has the advantages of economy, environmental protection, and high nutrition compared to animal protein. In this review, the preparation, characterization, and application of plant protein-based nanocarriers are summarized. The research deficiency and future prospects of plant protein nanocarriers are emphasized.

Synthesis and Characterization of Chelating Hyperbranched Polyester Nanoparticles for Cd(II) Ion Removal from Water

Chelating hyperbranched polyester (CHPE) nanoparticles have become an attractive new material family for developing high-capacity nanoscale chelating agents with highly branched structures and many functional groups in the main chains and end groups that can be used to remove heavy metals from water. In this study, a hyperbranched polyester with a particle size of 180–643 nm was synthesized with A₂+B₃ interfacial polymerization, using dimethylmalonyl chloride as the difunctional monomer (A₂) and 1,1,1-tris(4-hydroxyphenyl)ethane (THPE) as the trifunctional monomer (B₃). FTIR and NMR were used to characterize the CHPE and confirm the structure. The CHPE nanoparticles were generally considered hydrophilic, with an observed swelling capacity of 160.70%. The thermal properties of the CHPE nanoparticles were studied by thermal gravimetric analysis (TGA) with 1% mass loss at temperatures above 185 °C. The XRD of the CHPE nanoparticles showed a semi-crystalline pattern, as evident from the presence of peaks at positions ~18° and 20°. The nature of the surface of the CHPE was examined using SEM. Batch equilibrium was used to investigate the removal properties of the CHPE nanoparticles towards Cd(II) ions as a function of temperature, contact time, and Cd(II) concentration. The Cd(II) ion thermodynamics, kinetics, and desorption data on the CHPE nanoparticles were also studied.

Nano-Based Approved Pharmaceuticals for Cancer Treatment: Present and Future Challenges

Cancer is one of the main causes of death worldwide. To date, and despite the advances in conventional treatment options, therapy in cancer is still far from optimal due to the non-specific systemic biodistribution of antitumor agents. The inadequate drug concentrations at the tumor site led to an increased incidence of multiple drug resistance and the appearance of many severe undesirable side effects. Nanotechnology, through the development of nanoscale-based pharmaceuticals, has emerged to provide new and innovative drugs to overcome these limitations. In this review, we provide an overview of the approved nanomedicine for cancer treatment and the rationale behind their designs and applications. We also highlight the new approaches that are currently under investigation and the perspectives and challenges for nanopharmaceuticals, focusing on the tumor microenvironment and tumor disseminate cells as the most attractive and effective strategies for cancer treatments.

Nanomedicines: A Focus on Nanomaterials as Drug Delivery System with Current Trends and Future Advancement

The rapid advancement of nanomedicine presents novel alternatives that have the potential to transform health care. Targeted drug delivery as well as the synthesis of nanocarriers is a growing discipline that has been intensively researched to reduce the complexity of present medicines in a variety of diseases and to develop new treatment and diagnostic techniques. There are several designed nanomaterials used as a delivery system such as liposomes, micelles, dendrimers, polymers, carbon-based materials, and many other substances, which deliver the drug moiety directly into its targeted body area reducing toxic effect of conventional drug delivery, thus reducing the amount of drug required for therapeutic efficacy and offering many more advantages. Currently, these are used in many applications, including cancer treatment, imaging contrast agents, and biomarker detection and so on. This review provides a comprehensive update in the field of targeted nano-based drug delivery systems, by conducting a thorough examination of the drug synthesis, types, targets, and application of nanomedicines in improving the therapeutic efficiency.

Multiplexed Analysis of the Cellular Uptake of Polymeric Nanocarriers

Polymeric nanocarriers (PNCs) are versatile drug delivery vehicles capable of delivering a variety of therapeutics. Quantitatively monitoring their uptake in biological systems is essential for realizing their potential as next-generation delivery systems; however, existing quantification strategies are limited due to the challenges of detecting polymeric materials in complex biological samples. Here, we describe a metal-coded mass tagging approach that enables the multiplexed quantification of the PNC uptake in cells using mass spectrometry (MS). In this approach, PNCs are conjugated with ligands that bind strongly to lanthanide ions, allowing the PNCs to be sensitively quantitated by inductively coupled plasma-MS. The metal-coded tags have little effect on the properties or toxicity of the PNCs, making them biocompatible. We demonstrate that the conjugation of different metals to the PNCs enables the multiplexed analysis of cellular uptake of multiple distinct PNCs at the same time. This multiplexing capability should improve the design and optimization of PNCs by minimizing biological variability and reducing analysis time, effort, and cost.

Template-Free Synthesis of Porous Fluorescent Carbon Nanomaterials with Gluten for Intracellular Imaging and Drug Delivery

A series of carbon nanomaterials, including carbon dots, carbon nanorings (CNRs), and porous carbon nanoballs, were facilely prepared by a template-free hydrothermal treatment of gluten as the sole carbon source. Driven by the hydrophobicity interaction, a concentration-dependent self-assembly of gluten was observed in an aqueous solution, leading to the subsequent formation of different morphologies of carbon nanomaterials in a hydrothermal treatment. Among these carbon nanomaterials, the CNRs exhibit bright photoluminescence with a quantum yield of 47.0%. Furthermore, CNRs also have a large surface area and low toxicity, making them an excellent drug carrier for chemotherapeutics. A model drug molecule doxorubicin (DOX) was successfully loaded on the CNRs, and the CNRs-DOX complexes exhibit a pH-dependent DOX release behavior. Compared with free DOX, the CNRs-DOX complexes can induce a higher level of apoptosis and lower level of necrosis, showing promise as anticancer agents.

Biopharmaceutical nanoclusters: Towards the self-delivery of protein and peptide therapeutics

Protein and peptide biopharmaceuticals have had a major impact on the treatment of a number of diseases. There is a growing interest in overcoming some of the challenges associated with biopharmaceuticals, such as rapid degradation in physiological fluid, using nanocarrier delivery systems. Biopharmaceutical nanoclusters (BNCs) where the therapeutic protein or peptide is clustered together to form the main constituent of the nanocarrier system have the potential to mimic the benefits of more established nanocarriers (e.g., liposomal and polymeric systems) whilst eliminating the issue of low drug loading and potential side effects from additives. These benefits would include enhanced stability, improved absorption, and increased biopharmaceutical activity. However, the successful development of BNCs is challenged by the physicochemical complexity of the protein and peptide constituents as well as the dynamics of clustering. Here, we present and discuss common methodologies for the synthesis of therapeutic protein and peptide nanoclusters, as well as review the current status of this emerging field.

Bovine Serum Albumin-Based Nanoparticles: Preparation, Characterization, and Antioxidant Activity Enhancement of Three Main Curcuminoids from Curcuma longa

Bovine Serum Albumin (BSA) lipid hybrid nanoparticles are part of the new solutions to overcome low bioavailability of poor solubility drugs such as curcuminoids, which possess multiple biological advantages; however, they are counterbalanced by its short biological half-life. In this line, we prepared the three main curcuminoids: curcumin (CUR), desmethoxycurcumin (DMC), and bisdemethoxycurcumin (BDM)-loaded BSA nanoparticles. The three formulations were characterized by the average size, size distribution, crystallinity, weight loss, drug release, kinetic mechanism, and antioxidant activity. The developed method produced CUR-, DMC-, and BDM-loaded BSA nanoparticles with a size average of 15.83 ± 0.18, 17.29 ± 3.34, and 15.14 ± 0.14 nm for CUR, DMC, and BDM loaded BSA, respectively. FT-IR analysis confirmed the encapsulation, and TEM images showed their spherical shape. The three formulations achieved encapsulation efficiency upper to 96% and an exhibited significantly increased release from the nanoparticle compared to free compounds in water. The antioxidant activity was enhanced as well, in agreement with the improvement in water release, obtaining IC₅₀ values of 9.28, 11.70, and 15.19 µg/mL for CUR, DMC, and BDM loaded BSA nanoparticles, respectively, while free curcuminoids exhibited considerably lower antioxidant values in aqueous solution. Hence, this study shows promises for such hybrid systems, which have been ignored so far, regarding proper encapsulation, protection, and delivery of curcuminoids for the development of functional foods and pharmaceuticals.

Nanocarriers for Drug Delivery: An Overview with Emphasis on Vitamin D and K Transportation

Mounting evidence shows that supplementation with vitamin D and K or their analogs induces beneficial effects in various diseases, e.g., osteoarticular, cardiovascular, or carcinogenesis. The use of drugs delivery systems via organic and inorganic nanocarriers increases the bioavailability of vitamins and analogs, enhancing their cellular delivery and effects. The nanotechnology-based dietary supplements and drugs produced by the food and pharmaceutical industries overcome the issues associated with vitamin administration, such as stability, absorption or low bioavailability. Consequently, there is a continuous interest in optimizing the carriers' systems in order to make them more efficient and specific for the targeted tissue. In this pioneer review, we try to circumscribe the most relevant aspects related to nanocarriers for drug delivery, compare different types of nanoparticles for vitamin D and K transportation, and critically address their benefits and disadvantages.

Nanoparticle targeting of de novo profibrotic macrophages mitigates lung fibrosis

Current therapies for pulmonary fibrosis (PF) focus on slowing disease progression and reducing functional decline in patients by dampening the activation of fibroblasts and other implicated cells. There is a need for strategies that target the essential cells and signaling pathways involved in disease pathogenesis. Monocyte-derived macrophages (Mo-Macs) are known to express profibrotic genes and are involved in the pathogenesis of PF. Our results show that engineered mannosylated albumin nanoparticles specifically targeted disease-inducing Mo-Macs, and further, that nanoparticles efficiently delivered small-interfering RNA against profibrotic cytokine tumor growth factor β1 to prevent bleomycin-induced lung fibrosis.

The pathogenesis of lung fibrosis involves hyperactivation of innate and adaptive immune pathways that release inflammatory cytokines and growth factors such as tumor growth factor (TGF)β1 and induce aberrant extracellular matrix protein production. During the genesis of pulmonary fibrosis, resident alveolar macrophages are replaced by a population of newly arrived monocyte-derived interstitial macrophages that subsequently transition into alveolar macrophages (Mo-AMs). These transitioning cells initiate fibrosis by releasing profibrotic cytokines and remodeling the matrix. Here, we describe a strategy for leveraging the up-regulation of the mannose receptor CD206 in interstitial macrophages and Mo-AM to treat lung fibrosis. We engineered mannosylated albumin nanoparticles, which were found to be internalized by fibrogenic CD206⁺ monocyte derived macrophages (Mo-Macs). Mannosylated albumin nanoparticles incorporating TGFβ1 small-interfering RNA (siRNA) targeted the profibrotic subpopulation of CD206⁺ macrophages and prevented lung fibrosis. The findings point to the potential utility of mannosylated albumin nanoparticles in delivering TGFβ-siRNA into CD206⁺ profibrotic macrophages as an antilung fibrosis strategy.

Advances in aptamer-based nuclear imaging

Aptamers are short oligonucleotides that bind to specific target molecules. They have been extensively explored in biomedical applications, including biosensing, medical imaging, and disease treatment. Their adjustable affinity for specific biomarkers stimulates more translational efforts, such as nuclear imaging of tumors in preclinical and clinical settings. In this review, we present recent advances of aptamer-based nuclear imaging and compare aptamer tracers with other biogenic probes in forms of peptides, nanobodies, monoclonal antibodies, and antibody fragments. Fundamental properties of aptamer-based radiotracers are highlighted and potential directions to improve aptamer's imaging performance are discussed. Despite many translational obstacles to overcome, we envision aptamers to be a versatile tool for cancer nuclear imaging in the near future.

A review on cullin neddylation and strategies to identify its inhibitors for cancer therapy

The cullin-RING E3 ligases (CRLs) are the biggest components of the E3 ubiquitin ligase protein family, and they represent an essential role in various diseases that occur because of abnormal activation, particularly in tumors development. Regulation of CRLs needs neddylation, a post-translational modification involving an enzymatic cascade that transfers small, ubiquitin-like NEDD8 protein to CRLs. Many previous studies have confirmed neddylation as an enticing target for anticancer drug discoveries, and few recent studies have also found a significant increase in advancement in protein neddylation, including preclinical and clinical target validation to discover the neddylation inhibitor compound. In the present review, we first presented briefly the essence of CRLs' neddylation and its control, systematic analysis of CRLs, followed by the description of a few recorded chemical inhibitors of CRLs neddylation enzymes with recent examples of preclinical and clinical targets. We have also listed various structure-based pointing of protein-protein dealings in the CRLs' neddylation reaction, and last, the methods available to discover new inhibitors of neddylation are elaborated. This review will offer a concentrated, up-to-date, and detailed description of the discovery of neddylation inhibitors.

Emerging Albumin-Binding Anticancer Drugs for Tumor-Targeted Drug Delivery: Current Understandings and Clinical Translation

Albumin has shown remarkable promise as a natural drug carrier by improving pharmacokinetic (PK) profiles of anticancer drugs for tumor-targeted delivery. The exogenous or endogenous albumin enhances the circulatory half-lives of anticancer drugs and passively target the tumors by the enhanced permeability and retention (EPR) effect. Thus, the albumin-based drug delivery leads to a potent antitumor efficacy in various preclinical models, and several candidates have been evaluated clinically. The most successful example is Abraxane, an exogenous human serum albumin (HSA)-bound paclitaxel formulation approved by the FDA and used to treat locally advanced or metastatic tumors. However, additional clinical translation of exogenous albumin formulations has not been approved to date because of their unexpectedly low delivery efficiency, which can increase the risk of systemic toxicity. To overcome these limitations, several prodrugs binding endogenous albumin covalently have been investigated owing to distinct advantages for a safe and more effective drug delivery. In this review, we give account of the different albumin-based drug delivery systems, from laboratory investigations to clinical applications, and their potential challenges, and the outlook for clinical translation is discussed. In addition, recent advances and progress of albumin-binding drugs to move more closely to the clinical settings are outlined.

Computational Design of Homotetrameric Peptide Bundle Variants Spanning a Wide Range of Charge States

With the ability to design their sequences and structures, peptides can be engineered to realize a wide variety of functionalities and structures. Herein, computational design was used to identify a set of 17 peptides having a wide range of putative charge states but the same tetrameric coiled-coil bundle structure. Calculations were performed to identify suitable locations for ionizable residues (D, E, K, and R) at the bundle's exterior sites, while interior hydrophobic interactions were retained. The designed bundle structures spanned putative charge states of -32 to +32 in units of electron charge. The peptides were experimentally investigated using spectroscopic and scattering techniques. Thermal stabilities of the bundles were investigated using circular dichroism. Molecular dynamics simulations assessed structural fluctuations within the bundles. The cylindrical peptide bundles, 4 nm long by 2 nm in diameter, were covalently linked to form rigid, micron-scale polymers and characterized using transmission electron microscopy. The designed suite of sequences provides a set of readily realized nanometer-scale structures of tunable charge that can also be polymerized to yield rigid-rod polyelectrolytes.

Development, Therapeutic Evaluation and Theranostic Applications of Cubosomes on Cancers: An Updated Review

Cancer is a group of disorders characterized by aberrant gene function and alterations in gene expression patterns. In 2020, it was anticipated that 19 million new cancer cases would be diagnosed globally, with around 10 million cancer deaths. Late diagnosis and interventions are the leading causes of cancer-related mortality. In addition, the absence of comprehensive cancer therapy adds to the burden. Many lyotropic non-lamellar liquid-crystalline-nanoparticle-mediated formulations have been developed in the last few decades, with promising results in drug delivery, therapeutics, and diagnostics. Cubosomes are nano-structured liquid-crystalline particles made of specific amphiphilic lipids in particular proportions. Their ability to encapsulate lipophilic, hydrophilic, and amphiphilic molecules within their structure makes them one of a kind. They are biocompatible, versatile drug carriers that can deliver medications through various routes of administration. Many preclinical studies on the use of cubosomes in cancer treatment and theranostic applications have been conducted. However, before cubosomes may be employed in clinical practice, significant technical advances must be accomplished. This review summarizes the development of cubosomes and their multifunctional role in cancer treatment based on the most recent reports.

Graphene Oxide–Protein-Based Scaffolds for Tissue Engineering. Recent Advances and Applications

The field of tissue engineering is constantly evolving as it aims to develop bioengineered and functional tissues and organs for repair or replacement. Due to their large surface area and ability to interact with proteins and peptides, graphene oxides offer valuable physiochemical and biological features for biomedical applications and have been successfully employed for optimizing scaffold architectures for a wide range of organs, from the skin to cardiac tissue. This review critically focuses on opportunities to employ protein–graphene oxide structures either as nanocomposites or as biocomplexes and highlights the effects of carbonaceous nanostructures on protein conformation and structural stability for applications in tissue engineering and regenerative medicine. Herein, recent applications and the biological activity of nanocomposite bioconjugates are analyzed with respect to cell viability and proliferation, along with the ability of these constructs to sustain the formation of new and functional tissue. Novel strategies and approaches based on stem cell therapy, as well as the involvement of the extracellular matrix in the design of smart nanoplatforms, are discussed.

Protein Nanoparticles: Uniting the Power of Proteins with Engineering Design Approaches

Protein nanoparticles, PNPs, have played a long-standing role in food and industrial applications. More recently, their potential in nanomedicine has been more widely pursued. This review summarizes recent trends related to the preparation, application, and chemical construction of nanoparticles that use proteins as major building blocks. A particular focus has been given to emerging trends related to applications in nanomedicine, an area of research where PNPs are poised for major breakthroughs as drug delivery carriers, particle-based therapeutics or for non-viral gene therapy.

Casein Microgels as Benzydamine Hydrochloride Carriers for Prolonged Release

This research aims to investigate the properties of nano- and micro-sized casein hydrogels crosslinked by sodium tripolyphosphate as drug delivery systems. Benzydamine hydrochloride was chosen as a model hydrophilic drug. The gels were synthesized by varying different parameters: casein concentration, casein/crosslinking ratio, and addition of ethanol as a co-solvent. The electrostatic attractive interactions between the casein and the sodium tripolyphosphate were confirmed by FTIR spectroscopy. The particle sizes was determined by dynamic light scattering and varied in the range between several hundred nanometers and several microns. The yield of the gelation process was high for all investigated samples and varied between 55.3% and 78.3%. The encapsulation efficiency of the particles was strongly influenced by the casein concentration and casein/crosslinker ratio and its values were between 4.6% and 22.4%. The release study confirmed that casein particles are useful as benzydamine carriers and ensured prolonged release over 72 h.

Spherical nucleic acids: Organized nucleotide aggregates as versatile nanomedicine

Spherical nucleic acids (SNAs) are composed of a nanoparticle core and a layer of densely arranged oligonucleotide shells. After the first report of SNA by Mirkin and coworkers in 1996, it has created a significant interest by offering new possibilities in the field of gene and drug delivery. The controlled aggregation of oligonucleotides on the surface of organic/inorganic nanoparticles improves the delivery of genes and nucleic acid-based drugs and alters and regulates the biological profiles of the nanoparticle core within living organisms. Here in this review, we present an overview of the recent progress of SNAs that has speeded up their biomedical application and their potential transition to clinical use. We start with introducing the concept and characteristics of SNAs as drug/gene delivery systems and highlight recent efforts of bioengineering SNA by imaging and treatmenting various diseases. Finally, we discuss potential challenges and opportunities of SNAs, their ongoing clinical trials, and future translation, and how they may affect the current landscape of clinical practices. We hope that this review will update our current understanding of SNA, organized oligonucleotide aggregates, for disease diagnosis and treatment.

Biopolymer nanoparticles: a strategy to enhance stability, bioavailability, and biological effects of phenolic compounds as functional ingredients

Phenolic compounds are abundant in nature and have multiple beneficial effects on human health due to their antioxidant, anti-inflammatory, antithrombotic, antiallergenic, anticancer, and antiatherosclerotic properties. For this reason, phenolics are becoming relevant functional ingredients for several industries, mainly the food industry, derived from food consumer exigencies and regulations. However, the use of their beneficial properties still presents some limitations, such as chemical instability under environmental and processing conditions, which leads to structural changes and compromises their biological activities. They also present poor water solubility and sensitivity to pH changes, decreasing their bioavailability in the organism. The technologies for extraction and stabilization of these compounds have evolved rapidly in the development of different delivery systems to encapsulate sensitive active molecules. Biopolymeric nanoparticles are biodegradable polymer-based colloidal systems with sizes ranging from 1 to 1000 nm, and different techniques can be carried out to develop them. These systems have emerged as a green and effective alternative to improve stability, bioavailability, and biological effects of phenolic compounds. This comprehensive review aims to present an overview of recent advances in encapsulation processes of phenolic compounds within biopolymer nanoparticles as delivery systems and the impact on their physicochemical properties and biological effects after encapsulation. © 2021 Society of Chemical Industry.

Virus-Like Particles: Revolutionary Platforms for Developing Vaccines Against Emerging Infectious Diseases

Virus-like particles (VLPs) are nanostructures that possess diverse applications in therapeutics, immunization, and diagnostics. With the recent advancements in biomedical engineering technologies, commercially available VLP-based vaccines are being extensively used to combat infectious diseases, whereas many more are in different stages of development in clinical studies. Because of their desired characteristics in terms of efficacy, safety, and diversity, VLP-based approaches might become more recurrent in the years to come. However, some production and fabrication challenges must be addressed before VLP-based approaches can be widely used in therapeutics. This review offers insight into the recent VLP-based vaccines development, with an emphasis on their characteristics, expression systems, and potential applicability as ideal candidates to combat emerging virulent pathogens. Finally, the potential of VLP-based vaccine as viable and efficient immunizing agents to induce immunity against virulent infectious agents, including, SARS-CoV-2 and protein nanoparticle-based vaccines has been elaborated. Thus, VLP vaccines may serve as an effective alternative to conventional vaccine strategies in combating emerging infectious diseases.

Systematic studies into uniform synthetic protein nanoparticles

Nanoparticles are frequently pursued as drug delivery carriers due to their potential to alter the pharmacological profiles of drugs, but their broader utility in nanomedicine hinges upon exquisite control of critical nanoparticle properties, such as shape, size, or monodispersity. Electrohydrodynamic (EHD) jetting is a probate method to formulate synthetic protein nanoparticles (SPNPs), but a systematic understanding of the influence of crucial processing parameters, such as protein composition, on nanoparticle morphologies is still missing. Here, we address this knowledge gap by evaluating formulation trends in SPNPs prepared by EHD jetting based on a series of carrier proteins and protein blends (hemoglobin, transferrin, mucin, or insulin). In general, blended SPNPs presented uniform populations with minimum diameters between 43 and 65 nm. Size distributions of as-jetted SPNPs approached monodispersity as indicated by polydispersity indices (PDI_SEM) ranging from 0.11-0.19. Geometric factor analysis revealed high circularities (0.82-0.90), low anisotropy (<1.45) and excellent roundness (0.76-0.89) for all SPNPs prepared via EHD jetting. Tentatively, blended SPNPs displayed higher circularity and lower anisotropy, as compared to single-protein SPNPs. Secondary statistical analysis indicated that blended SPNPs generally present combined features of their constituents, with some properties driven by the dominant protein constituent. Our study suggests SPNPs made from blended proteins can serve as a promising drug delivery carrier owing to the ease of production, the composition versatility, and the control over their size, shape and dispersity.

Engineered protein nanodrug as an emerging therapeutic tool

Functional proteins are the most versatile macromolecules. They can be obtained by extraction from natural sources or by genetic engineering technologies. The outstanding selectivity, specificity, binding activity, and biocompatibility endow engineered proteins with outstanding performance for disease therapy. Nevertheless, their stability is dramatically impaired in blood circulation, hindering clinical translations. Thus, many strategies have been developed to improve the stability, efficacy, bioavailability, and productivity of therapeutic proteins for clinical applications. In this review, we summarize the recent progress in the fabrication and application of therapeutic proteins. We first introduce various strategies for improving therapeutic efficacy via bioengineering and nanoassembly. Furthermore, we highlight their diverse applications as growth factors, nanovaccines, antibody-based drugs, bioimaging molecules, and cytokine receptor antagonists. Finally, a summary and perspective for the future development of therapeutic proteins are presented.

An Up-to-Date Review of Natural Nanoparticles for Cancer Management

Cancer represents one of the leading causes of morbidity and mortality worldwide, imposing an urgent need to develop more efficient treatment alternatives. In this respect, much attention has been drawn from conventional cancer treatments to more modern approaches, such as the use of nanotechnology. Extensive research has been done for designing innovative nanoparticles able to specifically target tumor cells and ensure the controlled release of anticancer agents. To avoid the potential toxicity of synthetic materials, natural nanoparticles started to attract increasing scientific interest. In this context, this paper aims to review the most important natural nanoparticles used as active ingredients (e.g., polyphenols, polysaccharides, proteins, and sterol-like compounds) or as carriers (e.g., proteins, polysaccharides, viral nanoparticles, and exosomes) of various anticancer moieties, focusing on their recent applications in treating diverse malignancies.

New insight into the structural changes of apoferritin pores in the process of doxorubicin loading at an acidic pH: Molecular dynamics simulations

Apoferritin (APO-Fr) is one of the most investigated proteins proposed as an advanced structure for drug delivery systems. Herein, molecular dynamics simulation was employed to compare the opening of 3-fold and 4-fold pores in APO-Fr during the partial disassembly process at an acidic pH. We showed that more hydrophilic residues in the surface of 3-fold pores compared to 4-fold pores facilitate increased flexibility and a higher tendency to open. In particular, dissociation is induced by the presence of Doxorubicin (DOX) close to 3-fold pores. Our simulations showed loaded DOXs on the APO-Fr surface were mainly involved in the hydrogen bond interactions with the hydrophilic residues, suggesting the difficulty of hydrophobic drugs loading in APO-Fr with the partial disassembly process. However, π-π interactions as well as hydrogen bonds between protein and DOXs were mediated by the basic and acidic amino acids such as HIP128, GLU17, and LYS143 at the open pores, providing penetration of DOXs into the H-Apo-Fr. We conclude that increased drug encapsulations and loading capacity of hydrophobic drugs into the cavity of APO-Fr are feasible by further disassembly of openings to access the internal hydrophobic portions of the protein.

Drug Delivery of Natural Products Through Nanocarriers for Effective Breast Cancer Therapy: A Comprehensive Review of Literature

Despite recent advances in the diagnosis and treatment of breast cancer (BC), it remains a global health issue affecting millions of women annually. Poor prognosis in BC patients is often linked to drug resistance as well as the lack of effective therapeutic options for metastatic and triple-negative BC. In response to these unmet needs, extensive research efforts have been devoted to exploring the anti-BC potentials of natural products owing to their multi-target mechanisms of action and good safety profiles. Various medicinal plant extracts/essential oils and natural bioactive compounds have demonstrated anti-cancer activities in preclinical BC models. Despite the promising preclinical results, however, the clinical translation of natural products has often been hindered by their poor stability, aqueous solubility and bioavailability. There have been attempts to overcome these limitations, particularly via the use of nano-based drug delivery systems (NDDSs). This review highlights the tumour targeting mechanisms of NDDSs, the advantages and disadvantages of the major classes of NDDSs and their current clinical status in BC treatment. Besides, it also discusses the proposed anti-BC mechanisms and nanoformulations of nine medicinal plants' extracts/essential oils and nine natural bioactive compounds; selected via the screening of various scientific databases, including PubMed, Scopus and Google Scholar, based on the following keywords: "Natural Product AND Nanoparticle AND Breast Cancer". Overall, these nanoformulations exhibit improved anti-cancer efficacy against preclinical BC models, with some demonstrating biocompatibility with normal cell lines and mouse models. Further clinical studies are, however, warranted to ascertain their efficacy and biocompatibility in humans.

Collagen Nanoparticles in Drug Delivery Systems and Tissue Engineering

The versatile natural polymer, collagen, has gained vast attention in biomedicine. Due to its biocompatibility, biodegradability, weak antigenicity, biomimetics and well-known safety profile, it is widely used as a drug, protein and gene carrier, and as a scaffold matrix in tissue engineering. Nanoparticles develop favorable chemical and physical properties such as increased drug half-life, improved hydrophobic drug solubility and controlled and targeted drug release. Their reduced toxicity, controllable characteristics of scaffolds and stimuli-responsive behavior make them suitable in regenerative medicine and tissue engineering. Collagen associates and absorbs nanoparticles leading to significant impacts on their biological functioning in any biofluid. This review will discuss collagen nanoparticle preparation methods and their applications and developments in drug delivery systems and tissue engineering.

Promoted antitumor therapy on pancreatic cancer by a novel recombinant human albumin-bound miriplatin nanoparticle

Pancreatic cancer is an aggressive and highly lethal disease with a very poor prognosis. Our previous study found miriplatin can inhibit proliferation of various tumor cells, including pancreatic cancer cells. For the chemotherapy of pancreatic cancer, a novel recombinant human serum albumin (rHSA)-bound miriplatin nanoparticles (rHSA-miPt) were constructed by emulsion-diffusion evaporation method. The optimal formulation was composed of 150 mg of rHSA and 30 mg of miriplatin. The key parameters in rHSA-miPt production were 10 min of high-pressure homogenization in a solution with volume ratio of 10:2 of 5% glucose and chloroform. The rHSA-miPt was characterized with a particle size of 61 ± 10 nm, a zeta potential value of -18 ± 5 mV, encapsulation efficiency of 98.4%, drug loading of 16.4%, T_1/2 of 13.3 h and V_d of 0.5 L in Sprague Dawley rats. The concentrations of platinum (Pt) in the tumors were 15 and 22-fold higher than those in the blood at 24 and 72 h in tumor-bearing mice, respectively. The internalization of rHSA-miPt through caveolae-dependent pathway. In vitro, the half-maximal inhibitory concentration (IC₅₀) of rHSA-miPt was 12.7 μM vs more than 100 μM of gemcitabine (Gem). The inhibition rate of tumor growth was 76% of rHSA-miPt and 51% of Gem, respectively. Compared with Gem, rHSA-miPt was identified to be safer and less toxic based on body weight loss in mice (0% vs 20%), the survival rate of mice (100% vs 80%) and hematological and biochemical parameters of the mice including leukocytes, lymphocytes, neutrophils, monocytes, serum alanine aminotransferase and aspartate aminotransferase. The present study revealed that rHSA-miPt might be a promising candidate for pancreatic cancer therapy.

Engineering nanoparticle therapeutics for impaired wound healing in diabetes

Diabetes mellitus is a chronic disease characterized by increased blood glucose levels, leading to damage of the nerves blood vessels, subsequently manifesting as organ failures, wounds, or ulcerations. Wounds in patients with diabetes are further complicated because of reduced cytokine responses, infection, poor vascularization, and delayed healing processes. Surface-functionalized and bioengineered nanoparticles (NPs) have recently gained attention as emerging treatment modalities for wound healing in diabetes. Here, we review emerging therapeutic NPs to treat diabetic wounds and highlight their discrete delivery mechanisms and sites of action. We further critically assess the current challenges of these nanoengineered materials for successful clinical translation and discuss their potential for growth in the clinical marketplace.

Toxicology of Nanoparticles in Drug Delivery

Nanoparticles have revolutionized biomedicine especially in the field of drug delivery due to their intriguing properties such as systemic stability, level of solubility, and target site specificity. It can, however, be both beneficial and damaging depending on the properties in different environments, thus highlighting the importance of nanotoxicology studies before use in humans. Different types of nanoparticles have been used in drug delivery, and this review summarizes the recent toxicity studies of these nanoparticles. The toxicological evaluation of three widely used nanoparticles in drug delivery that are metal, lipid, and protein nanoparticles has been discussed in detail. Studies have recorded several toxic effects of various nanoparticles such as metal-based nanoparticles have been linked to increased oxidative stress and have the potential to infiltrate the cell nucleus and protein-based nanoparticles have been observed to have hepatotoxicity and nephrotoxicity as their adverse effects. Considering the increasing application of nanoparticles in drug delivery and the growing concerns of regulatory authorities regarding the toxicity of nanocarriers in living organisms, it requires urgent attention to identify the gap in toxicity studies. The review highlights the gap in toxicity studies and potential focus areas to overcome the existing challenges.

Gelatinase-sensitive nanoparticles loaded with photosensitizer and STAT3 inhibitor for cancer photothermal therapy and immunotherapy

Matrix metalloproteinase (MMP) 2 and 9 are the family members of proteases normally up-regulated in tumor to enhance the invasion and metastatic of tumor cells, and are associated with poor outcome of head and neck squamous cell carcinomas (HNSCCs). In the present work, MMPs-degradable gelatin nanoparticles (GNPs) are simultaneously loaded with photosensitizer indocyanine green (ICG) along with signal transducer activator of transcription 3 (STAT3) inhibitor NSC74859 (NSC, N) for efficient photothermal therapy (PTT) and immunotherapy of HNSCCs. In the tumor tissue, Gel-N-ICG nanoparticle was degraded and encapsulated ICG and NSC were effectively released. Under near-infrared (NIR) irradiation, the released ICG nanoparticles enabled effective photothermal destruction of tumors, and the STAT3 inhibitor NSC elicited potent antitumor immunity for enhanced cancer therapy. Based on two HNSCC mouse models, we demonstrated that Gel-N-ICG significantly delayed tumor growth without any appreciable body weight loss. Taken together, the strategy reported here may contribute that the stimuli-responsive proteases triggered nanoplatform could reduce tumor size more effectively in complex tumor microenvironment (TME) through combination of PTT and immunotherapy.

Amino Acids, Peptides, and Proteins: Implications for Nanotechnological Applications in Biosensing and Drug/Gene Delivery

Over various scientific fields in biochemistry, amino acids have been highlighted in research works. Protein, peptide- and amino acid-based drug delivery systems have proficiently transformed nanotechnology via immense flexibility in their features for attaching various drug molecules and biodegradable polymers. In this regard, novel nanostructures including carbon nanotubes, electrospun carbon nanofibers, gold nanoislands, and metal-based nanoparticles have been introduced as nanosensors for accurate detection of these organic compounds. These nanostructures can bind the biological receptor to the sensor surface and increase the surface area of the working electrode, significantly enhancing the biosensor performance. Interestingly, protein-based nanocarriers have also emerged as useful drug and gene delivery platforms. This is important since, despite recent advancements, there are still biological barriers and other obstacles limiting gene and drug delivery efficacy. Currently available strategies for gene therapy are not cost-effective, and they do not deliver the genetic cargo effectively to target sites. With rapid advancements in nanotechnology, novel gene delivery systems are introduced as nonviral vectors such as protein, peptide, and amino acid-based nanostructures. These nano-based delivery platforms can be tailored into functional transformation using proteins and peptides ligands based nanocarriers, usually overexpressed in the specified diseases. The purpose of this review is to shed light on traditional and nanotechnology-based methods to detect amino acids, peptides, and proteins. Furthermore, new insights into the potential of amino protein-based nanoassemblies for targeted drug delivery or gene transfer are presented.

Mechanisms Involved in Microglial-Interceded Alzheimer's Disease and Nanocarrier-Based Treatment Approaches

Alzheimer's disease (AD) is a common neurodegenerative disorder accountable for dementia and cognitive dysfunction. The etiology of AD is complex and multifactorial in origin. The formation and deposition of amyloid-beta (Aβ), hyperphosphorylated tau protein, neuroinflammation, persistent oxidative stress, and alteration in signaling pathways have been extensively explored among the various etiological hallmarks. However, more recently, the immunogenic regulation of AD has been identified, and macroglial activation is considered a limiting factor in its etiological cascade. Macroglial activation causes neuroinflammation via modulation of the NLRP3/NF-kB/p38 MAPKs pathway and is also involved in tau pathology via modulation of the GSK-3β/p38 MAPK pathways. Additionally, microglial activation contributes to the discrete release of neurotransmitters and an altered neuronal synaptic plasticity. Therefore, activated microglial cells appear to be an emerging target for managing and treating AD. This review article discussed the pathology of microglial activation in AD and the role of various nanocarrier-based anti-Alzeihmenr's therapeutic approaches that can either reverse or inhibit this activation. Thus, as a targeted drug delivery system, nanocarrier approaches could emerge as a novel means to overcome existing AD therapy limitations.

Nanoencapsulation as a General Solution for Lyophilization of Labile Substrates

Protein macromolecules occur naturally at the nanoscale. The use of a dedicated nanoparticle as a lyophilization excipient, however, has not been reported. Because biopolymeric and lipid nanoparticles often denature protein macromolecules and commonly lack the structural rigidity to survive the freeze-drying process, we hypothesized that surrounding an individual protein substrate with a nanoscale, thermostable exoshell (tES) would prevent aggregation and protect the substrate from denaturation during freezing, sublimation, and storage. We systematically investigated the properties of tES, including secondary structure and its homogeneity, throughout the process of lyophilization and found that tES have a near 100% recovery following aqueous reconstitution. We then tested the hypothesis that tES could encapsulate a model substrate, horseradish peroxidase (HRP), using charge complementation and pH-mediated controlled assembly. HRP were encapsulated within the 8 nm internal tES aqueous cavity using a simplified loading procedure. Time-course experiments demonstrated that unprotected HRP loses 95% of activity after 1 month of lyophilized storage. After encapsulation within tES nanoparticles, 70% of HRP activity was recovered, representing a 14-fold improvement and this effect was reproducible across a range of storage temperatures. To our knowledge, these results represent the first reported use of nanoparticle encapsulation to stabilize a functional macromolecule during lyophilization. Thermostable nanoencapsulation may be a useful method for the long-term storage of labile proteins.

Modified Desolvation Method Enables Simple One-Step Synthesis of Gelatin Nanoparticles from Different Gelatin Types with Any Bloom Values

Gelatin nanoparticles found numerous applications in drug delivery, bioimaging, immunotherapy, and vaccine development as well as in biotechnology and food science. Synthesis of gelatin nanoparticles is usually made by a two-step desolvation method, which, despite providing stable and homogeneous nanoparticles, has many limitations, namely complex procedure, low yields, and poor reproducibility of the first desolvation step. Herein, we present a modified one-step desolvation method, which enables the quick, simple, and reproducible synthesis of gelatin nanoparticles. Using the proposed method one can prepare gelatin nanoparticles from any type of gelatin with any bloom number, even with the lowest ones, which remains unattainable for the traditional two-step technique. The method relies on quick one-time addition of poor solvent (preferably isopropyl alcohol) to gelatin solution in the absence of stirring. We applied the modified desolvation method to synthesize nanoparticles from porcine, bovine, and fish gelatin with bloom values from 62 to 225 on the hundreds-of-milligram scale. Synthesized nanoparticles had average diameters between 130 and 190 nm and narrow size distribution. Yields of synthesis were 62-82% and can be further increased. Gelatin nanoparticles have good colloidal stability and withstand autoclaving. Moreover, they were non-toxic to human immune cells.

Bioengineering bacterial encapsulin nanocompartments as targeted drug delivery system

The development of Drug Delivery Systems (DDS) has led to increasingly efficient therapies for the treatment and detection of various diseases. DDS use a range of nanoscale delivery platforms produced from polymeric of inorganic materials, such as micelles, and metal and polymeric nanoparticles, but their variant chemical composition make alterations to their size, shape, or structures inherently complex. Genetically encoded protein nanocages are highly promising DDS candidates because of their modular composition, ease of recombinant production in a range of hosts, control over assembly and loading of cargo molecules and biodegradability. One example of naturally occurring nanocompartments are encapsulins, recently discovered bacterial organelles that have been shown to be reprogrammable as nanobioreactors and vaccine candidates. Here we report the design and application of a targeted DDS platform based on the Thermotoga maritima encapsulin reprogrammed to display an antibody mimic protein called Designed Ankyrin repeat protein (DARPin) on the outer surface and to encapsulate a cytotoxic payload. The DARPin9.29 chosen in this study specifically binds to human epidermal growth factor receptor 2 (HER2) on breast cancer cells, as demonstrated in an in vitro cell culture model. The encapsulin-based DDS is assembled in one step in vivo by co-expressing the encapsulin-DARPin9.29 fusion protein with an engineered flavin-binding protein mini-singlet oxygen generator (MiniSOG), from a single plasmid in Escherichia coli. Purified encapsulin-DARPin_miniSOG nanocompartments bind specifically to HER2 positive breast cancer cells and trigger apoptosis, indicating that the system is functional and specific. The DDS is modular and has the potential to form the basis of a multi-receptor targeted system by utilising the DARPin screening libraries, allowing use of new DARPins of known specificities, and through the proven flexibility of the encapsulin cargo loading mechanism, allowing selection of cargo proteins of choice.

Chitosan coated nanoparticles for efficient delivery of bevacizumab in the posterior ocular tissues via subconjunctival administration

In several ocular diseases, vascular endothelial growth factor (VEGF) level has been found to be unregulated. Bevacizumab, an anti-VEGF drug, is the most commonly used off level drug for diabetic retinopathy (DR). The present study was to evaluate the chitosan-coated poly (lactide-co-glycolic acid) nanoparticles (CS-PLGA NPs) for sustained and effective delivery of bevacizumab to posterior ocular tissues. The penetration of NP through sclera was studied by confocal laser scanning microscopy (CLSM). For pharmacokinetic study, bevacizumab loaded NPs were administered into the rat eye through subconjunctival injection (SCJ) and pharmacokinetic parameters were compared to drug solution. CLSM and pharmacokinetic study showed better penetration of formulation and higher concentration of bevacizumab in posterior ocular tissues. In retinopathy model, CS-PLGA NPs by SCJ route showed more reduction of VEGF level in retina than the topical and intravitreal administration of formulation. Thus, CS-coated PLGA NPs can be potentially useful as carriers to target retina.

ERK-Peptide-Inhibitor-Modified Ferritin Enhanced the Therapeutic Effects of Paclitaxel in Cancer Cells and Spheroids

Rational design of a drug delivery system with enhanced therapeutic potency is critical for efficient tumor chemotherapy. Many protein-based drug delivery platforms have been designed to deliver drugs to target sites and improve the therapeutic efficacy. In this study, paclitaxel (PTX) molecules were encapsulated within an apoferritin nanocage-based drug delivery system with the modification of an extracellular-signal-regulated kinase (ERK) peptide inhibitor at the C-terminus of ferritin (HERK). Apoferritin is an endogenous nano-sized spherical protein which has the ability to specially bind to a majority of tumor cells via interacting with transferrin receptor 1. The ERK peptide inhibitor is a peptide which can disrupt the interaction of MEK with ERK in the mitogen-activated protein kinase/ERK pathway. By combining the targeted delivery effect of ferritin and the inhibitory effect of the ERK peptide inhibitor, the newly fabricated ferritin carrier nanoparticle HERK could still be taken up by tumor cells, and it displayed higher cell cytotoxicity than the parent ferritin. After loading with PTX, HERK-PTX displayed a favorable anticancer effect in human breast cancer cells MDA-MB-231 and lung carcinoma cells A549. The remarkable inhibitory effect on MDA-MB-231 tumor spheroids was also identified. These results indicated that the constructed HERK nanocarrier is a promising multi-functional drug delivery vehicle to enhance the therapeutic effect of drugs in cancer therapy.

The Development of the Innovative Synthesis Methodology of Albumin Nanoparticles Supported by Their Physicochemical, Cytotoxic and Hemolytic Evaluation

Many studies are being performed to develop effective carriers for controlled cytostatic delivery wherein albumin is a promising material due to its tendency to accumulate near cancer cells. The novelty of this work involves the development of the synthesis methodology of albumin nanoparticles and their biological and physicochemical evaluation. Albumin particles were obtained via the salt-induced precipitation and K3PO4 was used as a salting-out agent. Various concentrations of protein and salting-out agent solutions were mixed using a burette or a syringe system. It was proved that the size of the particles depended on the concentrations of the reagents and the methodology applied. As a result of a process performed using a burette and 2 M K3PO4, albumin spheres having a size 5-25 nm were obtained. The size of nanospheres and their spherical shape was confirmed via TEM analysis. The use of a syringe system led to preparation of particles of large polydispersity. The highest albumin concentration allowing for synthesis of homogeneous particles was 2 g/L. The presence of albumin in spheres was confirmed via the FT-IR technique and UV-Vis spectroscopy. All samples showed no cytotoxicity towards normal human dermal fibroblasts and no hemolytic properties against human erythrocytes (the hemolysis did not exceed 2.5%).

Functionalized Particles Designed for Targeted Delivery

Pure bioactive compounds alone can only be exceptionally administered in medical treatment. Usually, drugs are produced as various forms of active compounds and auxiliary substances, combinations assuring the desired healing functions. One of the important drug forms is represented by a combination of active substances and particle-shaped polymer in the nano- or micrometer size range. The review describes recent progress in this field balanced with basic information. After a brief introduction, the paper presents a concise overview of polymers used as components of nano- and microparticle drug carriers. Thereafter, progress in direct synthesis of polymer particles with functional groups is discussed. A section is devoted to formation of particles by self-assembly of homo- and copolymer-bearing functional groups. Special attention is focused on modification of the primary functional groups introduced during particle preparation, including introduction of ligands promoting anchorage of particles onto the chosen living cell types by interactions with specific receptors present in cell membranes. Particular attention is focused on progress in methods suitable for preparation of particles loaded with bioactive substances. The review ends with a brief discussion of the still not answered questions and unsolved problems.

Potentiating Therapeutic Effects of Epidermal Growth Factor Receptor Inhibition in Triple-Negative Breast Cancer

Triple-negative breast cancer (TNBC) is a subset of breast cancer with aggressive characteristics and few therapeutic options. The lack of an appropriate therapeutic target is a challenging issue in treating TNBC. Although a high level expression of epidermal growth factor receptor (EGFR) has been associated with a poor prognosis among patients with TNBC, targeted anti-EGFR therapies have demonstrated limited efficacy for TNBC treatment in both clinical and preclinical settings. However, with the advantage of a number of clinically approved EGFR inhibitors (EGFRis), combination strategies have been explored as a promising approach to overcome the intrinsic resistance of TNBC to EGFRis. In this review, we analyzed the literature on the combination of EGFRis with other molecularly targeted therapeutics or conventional chemotherapeutics to understand the current knowledge and to provide potential therapeutic options for TNBC treatment.