Albumin nanoparticles with predictable size by desolvation procedure

Albumin Nanoparticle-Based Drug Delivery Systems

Nanoparticle-based systems are extensively investigated for drug delivery. Among others, with superior biocompatibility and enhanced targeting capacity, albumin appears to be a promising carrier for drug delivery. Albumin nanoparticles are highly favored in many disease therapies, as they have the proper chemical groups for modification, cell-binding sites for cell adhesion, and affinity to protein drugs for nanocomplex generation. Herein, this review summarizes the recent fabrication techniques, modification strategies, and application of albumin nanoparticles. We first discuss various albumin nanoparticle fabrication methods, from both pros and cons. Then, we provide a comprehensive introduction to the modification section, including organic albumin nanoparticles, metal albumin nanoparticles, inorganic albumin nanoparticles, and albumin nanoparticle-based hybrids. We finally bring further perspectives on albumin nanoparticles used for various critical diseases.

Antibody desolvation with sodium chloride and acetonitrile generates bioactive protein nanoparticles

About 30% of the FDA approved drugs in 2021 were protein-based therapeutics. However, therapeutic proteins can be unstable and rapidly eliminated from the blood, compared to conventional drugs. Furthermore, on-target but off-tumor protein binding can lead to off-tumor toxicity, lowering the maximum tolerated dose. Thus, for effective treatment therapeutic proteins often require continuous or frequent administration. To improve protein stability, delivery and release, proteins can be encapsulated inside drug delivery systems. These drug delivery systems protect the protein from degradation during (targeted) transport, prevent premature release and allow for long-term, sustained release. However, thus far achieving high protein loading in drug delivery systems remains challenging. Here, the use of protein desolvation with acetonitrile as an intermediate step to concentrate monoclonal antibodies for use in drug delivery systems is reported. Specifically, trastuzumab, daratumumab and atezolizumab were desolvated with high yield (∼90%) into protein nanoparticles below 100 nm with a low polydispersity index (<0.2). Their size could be controlled by the addition of low concentrations of sodium chloride between 0.5 and 2 mM. Protein particles could be redissolved in aqueous solutions and redissolved antibodies retained their binding activity as evaluated in cell binding assays and exemplified for trastuzumab in an ELISA.

Quality by design fostered fabrication of cabazitaxel loaded pH-responsive Improved nanotherapeutics against prostate cancer

Cabazitaxel has been approved for the treatment of prostate cancer since 2010. However, its poor solubility and permeability pitfalls prevent its accumulation at the target site and promote severe adverse effects. About 90% of prostate cancer (PCa) patients suffer from bone metastasis. This advent reports the development of CBZ-loaded pH-responsive polydopamine nanoparticles (CBZ NP) against metastatic PCa cells. Quality by design (QbD) and multivariate analysis tools were employed for the optimization of CBZ NP. Amorphisation of CBZ along with metastatic microenvironment responsive release was observed thereby imparting spatial release and circumventing solubility pitfalls. CBZ NP retained its cytotoxic potential, with a significant increase in quantitative cellular uptake. Apoptotic markers observed from nuclear staining with elevated reactive oxygen species (ROS) and mitochondrial damage revealed by JC-1 staining demonstrated the efficacy of CBZ NP against PC-3 cells with good serum stability and diminished hemolysis. Cell cycle analysis revealed substantial S and G2/M phase arrest with enhancement in apoptosis was observed. Western blot studies revealed an elevation in caspase-1 and suppression in Bcl-2 indicating enhanced apoptosis compared to the control group. Substantial reduction in the diameter of 3D-Tumoroid and enhanced cell proliferation inhibition indicated the efficacy of CBZ NP in PCa. Thus, we conclude that CBZ NP could be a promising Nanotherapeutic approach for PCa.

Unraveling the Formation of Gelatin Nanospheres by Means of Desolvation

Gelatin nanoparticles (GNPs) have been widely studied for a plethora of biomedical applications, but their formation mechanism remains poorly understood, which precludes precise control over their physicochemical properties. This leads to time-consuming parameter adjustments without a fundamental grasp of the underlying mechanism. Here, we analyze and visualize in a time-resolved manner the mechanism by which GNPs are formed during desolvation of gelatin as a function of gelatin molecular weight and type of desolvating agent. Through various analytical and imaging techniques, we unveil a multistage process that is initiated by the formation of primary particles that are ∼18 nm in diameter (wet state). These primary particles subsequently assemble into colloidally stable GNPs with a raspberry-like structure and a hydrodynamic diameter of ∼300 nm. Our results create a basic understanding of the formation mechanism of gelatin nanoparticles, which opens new opportunities for precisely tuning their physicochemical and biofunctional properties.

Quality by design endorsed fabrication of Ibrutinib-loaded human serum albumin nanoparticles for the management of leukemia

Ibrutinib (IB), a BCS class II drug suffers from limited aqueous solubility, short half-life and extensive first-pass metabolism. In this project, we aim to recruit the desirable properties of human serum albumin (HSA) as a biocompatible drug carrier to circumvent nanoparticle-associated drawbacks. Quality by design and multivariate analysis was used for the optimization of IB-NPs. Cell culture studies performed on the K562 cell line revealed that the Ibrutinib-loaded HSA NPs demonstrated improved cytotoxicity, drug uptake, and reactive oxygen species generation in the leukemic K562 cells. Cell cycle analysis revealed G2/M phase retention of the leukemia cells. In vitro protein corona and hemolysis studies revealed superior hematological stability compared to the free drug which showed greater than 40 % hemolysis. In vitro drug release studies showed prolonged release profile till 48 h. Pharmacokinetic studies demonstrated a 2.31-fold increase in AUC and an increase in half-life from 0.43 h to 2.887 h with a tremendous reduction in clearance and elimination rate indicating prolonged systemic circulation which is desirable in leukemia. Hence, we conclude that IB-loaded albumin nanoparticles could be a promising approach for the management of leukemia.

Dopamine-Conjugated Bovine Serum Albumin Nanoparticles Containing pH-Responsive Catechol-V(III) Coordination for In Vitro and In Vivo Drug Delivery

V(III) instead of commonly used Fe(III) provided a rich tris-catechol-metal coordination at pH 7.4, which is important for slow drug release at physiological pH. Bovine serum albumin (BSA) functionalized with catechol-containing dopamine (D) and cross-linked using tris-catechol-V(III) coordination yielded pH-responsive compact D-BSA NPs (253 nm). However, conversion to bis- and/or mono-catechol-V(III) complexes in an acidic medium resulted in degradation of NPs and rapid release of doxorubicin (DOX). It was shown that D-BSA NPs entered cancerous MCF-7 cells (66%) more efficiently than non-cancerous HEK293T (33%) in 3 h. Also, DOX-loaded NPs reduced cell viability of MCF-7 by 75% and induced apoptosis in a majority of cells after 24 h. Biodegradability and lack of hemolytic activity were shown in vitro, whereas a lack of toxicity was shown in histological sections of zebrafish. Furthermore, 30% of circulating tumor cells in vasculature in 24 h were killed by DOX-loaded NPs shown with the zebrafish CTC xenograft model.

Nanocarriers with Multiple Cargo Load-A Comprehensive Preparation Guideline Using Orthogonal Strategies

Multifunctional nanocarriers enhance the treatment efficacy for modern therapeutics and have gained increasing importance in biomedical research. Codelivery of multiple bioactive molecules enables synergistic therapies. Coencapsulation of cargo molecules into one nanocarrier system is challenging due to different physicochemical properties of the cargo molecules. Additionally, coencapsulation of multiple molecules simultaneously shall proceed with high control and efficiency. Orthogonal approaches for the preparation of nanocarriers are essential to encapsulate sensitive bioactive molecules while preserving their bioactivity. Preparation of nanocarriers by physical processes (i.e., self-assembly or coacervation) and chemical reactions (i.e., click reactions, polymerizations, etc.) are considered as orthogonal methods to most cargo molecules. This review shall act as a guideline to allow the reader to select a suitable preparation protocol for a desired nanocarrier system. This article helps to select for combinations of cargo molecules (hydrophilic-hydrophobic, small-macro, organic-inorganic) with nanocarrier material and synthesis protocols. The focus of this article lies on the coencapsulation of multiple cargo molecules into biocompatible and biodegradable nanocarriers prepared by orthogonal strategies. With this toolbox, the selection of a preparation method for a known set of cargo molecules to prepare the desired biodegradable and loaded nanocarrier shall be provided.

The interplay of solvent-drug-protein interactions during albumin nanoparticles formulations for temozolomide delivery to brain cancer cells

OBJECTIVES

Temozolomide (TMZ), the first line for glioma therapy, suffers from stability at physiological pH. TMZ was selected as a challenging model drug for loading into human serum albumin nanoparticles (HSA NPs). Our aim is to optimise the conditions for TMZ loading into HSA NPs while ensuring TMZ stability.

METHODS

Blank and TMZ-HSA NPs were fabricated using the de-solvation technique and the effect of different formulation parameters was evaluated.

KEY FINDINGS

For blank NPs, crosslinking time had no significant effect on NPs' size while acetone produced significantly smaller particles than ethanol. Upon drug loading, though TMZ was stable in acetone and ethanol as single agents yet, ethanol-based NPs showed misleadingly high EE% due to drug instability in ethanol formulations as evident by the UV spectrum.The optimum conditions for drug-loaded particles were: 10 mg/ml HSA, 4 mg TMZ using acetone, yielded NPs with 145 nm in diameter, ξ of -16.98 mV and 0.16% DL. The selected formula reduced the cell viabilities of GL261 glioblastoma cells and BL6 glioblastoma stem cells to 61.9% and 38.3%, respectively.

CONCLUSIONS

Our results corroborated that careful manipulation of TMZ formulation processing parameters is crucial for encapsulating such chemically unstable dug while simultaneously ensuring its chemical stability.

Human Serum Albumin Nanoparticles: Synthesis, Optimization and Immobilization with Antituberculosis Drugs

The aim of this study was to create nanoparticles of human serum albumin immobilized with anti-TB drugs (rifampicin, isoniazid) using the desolvation method. Central Composite Design (CCD) was applied to study the effect of albumin, urea, L-cysteine, rifampicin and isoniazid concentration on particle size, polydispersity and loading degree of the drugs. The optimized nanoparticles were spherical in shape with an average particle size of 216.7 ± 3.7 nm and polydispersity of 0.286 ± 4.9. The loading degree of rifampicin and isoniazid in the optimized nanoparticles were 44% and 27%, respectively. The obtained nanoparticles were examined by Fourier-transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC); the results showed the absence of drug-polymer interactions. The drug release from the polymer matrix was studied using dialysis membranes.

Development of Carvedilol-Loaded Albumin-Based Nanoparticles with Factorial Design to Optimize In Vitro and In Vivo Performance

Carvedilol, an anti-hypertensive medication commonly prescribed by healthcare providers, falls under the BCS class II category due to its low-solubility and high-permeability characteristics, resulting in limited dissolution and low absorption when taken orally. Herein, carvedilol was entrapped into bovine serum albumin (BSA)-based nanoparticles using the desolvation method to obtain a controlled release profile. Carvedilol-BSA nanoparticles were prepared and optimized using 3² factorial design. The nanoparticles were characterized for their particle size (Y₁), entrapment efficiency (Y₂), and time to release 50% of carvedilol (Y₃). The optimized formulation was assessed for its in vitro and in vivo performance by solid-state, microscopical, and pharmacokinetic evaluations. The factorial design showed that an increment of BSA concentration demonstrated a significant positive effect on Y₁ and Y₂ responses with a negative effect on Y₃ response. Meanwhile, the carvedilol percentage in BSA nanoparticles represented its obvious positive impact on both Y₁ and Y₃ responses, along with a negative impact on Y₂ response. The optimized nanoformulation entailed BSA at a concentration of 0.5%, whereas the carvedilol percentage was 6%. The DSC thermograms indicated the amorphization of carvedilol inside the nanoparticles, which confirmed its entrapment into the BSA structure. The plasma concentrations of carvedilol released were observable from optimized nanoparticles up to 72 h subsequent to their injection into rats, revealing their longer in vivo circulation time compared to pure carvedilol suspension. This study offers new insight into the significance of BSA-based nanoparticles in sustaining the release of carvedilol and presents a potential value-added in the remediation of hypertension.

Monophosphoryl lipid A-adjuvanted nucleoprotein-neuraminidase nanoparticles improve immune protection against divergent influenza viruses

Universal influenza vaccines are urgently needed to prevent recurrent influenza epidemics and inevitable pandemics. We generated double-layered protein nanoparticles incorporating two conserved influenza antigens-nucleoprotein and neuraminidase-through a two-step desolvation-crosslinking method. These protein nanoparticles displayed immunostimulatory properties to antigen-presenting cells by promoting inflammatory cytokine (IL-6 and TNF-α) secretion from JAWS II dendric cells. The nanoparticle immunization induced significant antigen-specific humoral and cellular responses, including antigen-binding and neutralizing antibodies, antibody- and cytokine (IFN-γ and IL-4)-secreting cells, and NP147-155 tetramer-specific cytotoxic T lymphocyte (CTL) responses. Co-administration of monophosphoryl lipid A (MPLA, a toll-like receptor 4 agonist) with the protein nanoparticles further improved immune responses and conferred heterologous and heterosubtypic influenza protection. The MPLA-adjuvanted nanoparticles reduced lung inflammation post-infection. The results demonstrated that the combination of MPLA and conserved protein nanoparticles could be developed into an improved universal influenza vaccine strategy.

Risk-Assessment-Based Optimization Favours the Development of Albumin Nanoparticles with Proper Characteristics Prior to Drug Loading

Albumin nanocarrier research and development is a challenging area in the field of personalized medicine and in providing advanced therapeutic solutions. Albumin as a biocompatible, nonimmunogenic, and non-toxic protein carrier that can be exploited to conjugate drugs with poor bioavailability to improve on this feature. With many different perspectives and desired target profiles, a systematic structural approach must be used in nanoparticle development. The extended Research and Development (R&D) Quality by Design thinking and methodology proved to be useful in case of specific nanoparticle development processes before. However, the coacervation method is the most frequently applied preparation method for HSA nanoparticles; there is a lack of existing research work which has directly determined the influence of process parameters, control strategy, or design space. With a quality-management-driven strategy, a knowledge space was developed for these versatile nanoparticles and an initial risk assessment was conducted on the quality-affecting factors regarding the coacervation method, followed by an optimization process via Plackett–Burman and Box–Behnken experimental design. As a result of screening the effect of process variables on the fabrication of HSA nanoparticles, an optimized colloidal drug delivery system was engineered with desired nanoparticulate properties.

A Novel Thermal-driven Self-assembly Method to Prepare Albumin Nanoparticles: Formation Kinetics, Degradation Behavior and Formation Mechanism

Nanoparticles based on bovine serum albumin (BSA), which shares 76% homology with human serum albumin (HSA), have emerged as a promising candidate for the efficient delivery of anticancer drugs. Thermal-driven self-assembly is a novel organic solvent-free approach to produce albumin nanoparticles. In our previous study, some features of this nanoparticle such as drug loading efficiency, drug encapsulation efficiency and drug release kinetics have been evaluated. However, the formation mechanism that determines the above nanoparticle properties remains unclear. Here, we investigated the formation kinetics and mechanism using spectroscopic methods including fluorescence spectroscopy, circular dichroism (CD) and differential scanning calorimetry (DSC). We also applied chemical analysis methods that measured the content changes of albumin active groups and vanillin. To verify the covalent networks in the nanoparticles, trypsin and glutathione (GSH) were used separately to cleave the peptide bonds and disulfide bridges, and dynamic light scattering (DLS) and sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) were used to analyze the degraded samples. BSA nanoparticles started to form at 10 min and were completely formed at 120 min. With the digestion of trypsin, more than 50% of the nanoparticles were degraded within 60 min. CD spectra showed that α-helical structure of BSA decreased from 42.3% to 39.8% and 37.7% after heating for 10 and 60 min, respectively. In the DSC thermogram, the melting peak of BSA nanoparticles was 229.14℃, which is about 12℃ higher than the physical mixture of BSA and vanillin, indicating that chemical reactions occurred during the nanoparticle formation and formed a new more stable substance. Moreover, the results of active group assay, GSH degradation and SDS-PAGE experiments also proved that disulfide bonds and peptide bonds were formed between BSA molecules, whereas Schiff bases were formed between BSA and vanillin molecules. Formation kinetics and degradation behavior are important properties to characterize albumin nanoparticles and should be paid attention to. Not only that, this study also provides an effective way to study the formation mechanism of protein-based nanodrug delivery systems.

J-aggregates albumin-based NIR-II fluorescent dye nanoparticles for cancer phototheranostics

Phototheranostics, relying on energy conversions of fluorophores upon excitation, integrating diagnostic fluorescence imaging and photo-driven therapy, represents a promising strategy for cancer precision medicine. Compared with the first near-infrared biological window (NIR-I), fluorophores imaged in the second window (NIR-II, 1000–1700 ​nm) exhibit a higher temporal and spatial resolution and tissue penetration depth. Polymethine cyanine-based dye IR1061 is a typical NIR-II small-molecule organic fluorophore, but its low water solubility and short circulation time limiting its biological applications. Therefore, human serum albumin (HSA) nanoparticles with great biocompatibility and biosafety were employed to fabricate hydrophobic IR1061, which exhibited red-shifted absorption band as typical for J-aggregates. Moreover, IR1061@HSA nanoparticles can be successfully used for NIR-II imaging to noninvasively visualize the tumor vascular networks, as well as real-time intraoperative image-guided tumor resection. Interestingly, benefiting from the high photothermal conversion efficiency brought by J-aggregates, IR1061@HSA nanoparticles were also explored for photothermal therapy (PTT) and cause efficient thermal ablation of tumors. Overall, IR1061@HSA, as a novel J-aggregates albumin-based NIR II dye nanoparticle with high biocompatibility, provides an integrated versatile platform for cancer phototheranostics with promising clinical translation prospects.

Coacervates: recent developments as nanostructure delivery platforms for therapeutic biomolecules

Coacervation is a liquid-liquid phase separation that can occur in solutions of macromolecules through self-assembly or electrostatic interactions. Recently, coacervates composed of biocompatible macromolecules have been actively investigated as nanostructure platforms to encapsulate and deliver biomolecules such as proteins, RNAs, and DNAs. One particular advantage of coacervates is that they are derived from aqueous solutions, unlike other nanoparticle delivery systems that often require organic solvents. In addition, coacervates achieve high loading while maintaining the viability of the cargo material. Here, we review recent developments in the applications of coacervates and their limitations in the delivery of therapeutic biomolecules. Important factors for coacervation include molecular structures of the polyelectrolytes, mixing ratio, the concentration of polyelectrolytes, and reaction conditions such as ionic strength, pH, and temperature. Various compositions of coacervates have been shown to deliver biomolecules in vitro and in vivo with encouraging activities. However, major hurdles remain for the systemic route of administration other than topical or local delivery. The scale-up of manufacturing methods suitable for preclinical and clinical evaluations remains to be addressed. We conclude with a few research directions to overcome current challenges, which may lead to successful translation into the clinic.

Triggering the nanophase separation of albumin through multivalent binding to glycogen for drug delivery in 2D and 3D multicellular constructs

Engineered nanoparticles for the encapsulation of bioactive agents hold promise to improve disease diagnosis, prevention and therapy. To advance this field and enable clinical translation, the rational design of nanoparticles with controlled functionalities and a robust understanding of nanoparticle-cell interactions in the complex biological milieu are of paramount importance. Herein, a simple platform obtained through the nanocomplexation of glycogen nanoparticles and albumin is introduced for the delivery of chemotherapeutics in complex multicellular 2D and 3D systems. We found that the dendrimer-like structure of aminated glycogen nanoparticles is key to controlling the multivalent coordination and phase separation of albumin molecules to form stable glycogen-albumin nanocomplexes. The pH-responsive glycogen scaffold conferred the nanocomplexes the ability to undergo partial endosomal escape in tumour, stromal and immune cells while albumin enabled nanocomplexes to cross endothelial cells and carry therapeutic agents. Limited interactions of nanocomplexes with T cells, B cells and natural killer cells derived from human blood were observed. The nanocomplexes can accommodate chemotherapeutic drugs and release them in multicellular 2D and 3D constructs. The drugs loaded on the nanocomplexes retained their cytotoxic activity, which is comparable with the activity of the free drugs. Cancer cells were found to be more sensitive to the drugs in the presence of stromal and immune cells. Penetration and cytotoxicity of the drug-loaded nanocomplexes in tumour mimicking tissues were validated using a 3D multicellular-collagen construct in a perfusion bioreactor. The results highlight a simple and potentially scalable strategy for engineering nanocomplexes made entirely of biological macromolecules with potential use for drug delivery.

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.

Isoniazid-Loaded Albumin Nanoparticles: Taguchi Optimization Method

Tuberculosis is one of the dangerous infectious diseases, killing over a million people worldwide each year. The search for new dosage forms for the treatment of drug-resistant tuberculosis is an actual task. Biocompatible polymer nanoparticles, in particular bovine serum albumin (BSA), are promising drug carriers. Nanoparticle (NP) parameters such as diameter, polydispersity, bioactive substance loading, and NP yield are very important when it comes to drug transport through the bloodstream. The most well-known and widely used first-line anti-tuberculosis drug, isoniazid (INH), is being used as a drug. BSA-INH NPs were obtained by an ethanol desolvation of an aqueous protein solution in the drug presence. The peculiarity of the method is that natural components, namely urea and cysteine, are used for the stabilization of BSA-INH NPs after desolvation. The characteristics of the obtained BSA-INH NPs are significantly affected by the concentration of protein, isoniazid, urea, and cysteine in the solution. The aim of the present study is to investigate the concentration effect of the system reacting components on the parameters of the NPs that are obtained. We have chosen the concentrations of four reacting components, i.e., BSA, isoniazid, urea, and cysteine, as controlling factors and applied the Taguchi method to analyze which concentration of each component has an important effect on BSA-INH NPs characteristics.

A natural protein based platform for the delivery of Temozolomide acid to glioma cells

Glioblastoma is one of the most difficult to treat cancers with poor prognosis and survival of around one year from diagnosis. Effective treatments are desperately needed. This work aims to prepare temozolomide acid (TMZA) loaded albumin nanoparticles, for the first time, to target glioblastoma (GL261) and brain cancer stem cells (BL6). TMZA was loaded into human serum albumin nanoparticles (HSA NPs) using the desolvation method. A response surface 3-level factorial design was used to study the effect of different formulation parameters on the drug loading and particle size of NPs. The optimum conditions were found to be: 4 mg TMZA with 0.05% sodium cholate. This yielded NPs with particle size and drug loading of 111.7 nm and 5.5% respectively. The selected formula was found to have good shelf life and serum stability but with a relatively fast drug release pattern. The optimized NPs showed excellent cellular uptake with ∼ 50 and 100% of cells were positive for NP uptake after 24 h incubation with both GL261 and BL6 glioblastoma cell lines, respectively. The selected formula showed high cytotoxicity with ̴ 20% cell viability at 1 mM TMZA after 72 h incubation time. Finally, the fluorescently labelled NPs showed co-localization with the bioluminescent syngeneic BL6 intra-cranial tumour mouse model after intravenous administration.

Nanoparticles as an effective drug delivery system in COVID-19

Background

The global healthcare sector has been dealing with a situation known as a novel severe acute respiratory syndrome (SARS-CoV-2) since the end of 2019. Covid-19 is an acronym for Covid-19 (Coronavirus Disease- 2019). It causes a respiratory infection that includes cold, sneezing and coughing, and pneumonia. In the case of an animal, it causes diarrhea and upper respiratory diseases. Covid-19 transmitted human to human via airborne droplets. First Covid-19 emerged in Wuhan market China and it spread rapidly throughout the World. As we know nanoparticles are a novel drug delivery system. They have various advantageous effects like increasing the efficacy of the drug, safety, etc. In this review, we study about the nanoparticles and summarize how it is effective during drug delivery system in Covid-19. Chitosan is a much focused biopolymeric nanoparticle. It delivers drugs to the specific target site. In a recent health crisis, chitosan nanoparticles are one of the ways to release drugs of Covid-19, and specifically in the lungs of the affected patients. We studied and extracted our data from various research papers, review papers, and some other articles.

Objective

The main goal is to study the nanoparticles and their future aspects which is an effective drug delivery system in Covid-19.

Methods

The bibliographic search was done through a systematic search. The terms “Nanoparticles”, “Covid-19 ”, “Drug delivery” etc. were used to search the databases/search engines like “Google Scholar”, “NCBI”, “PubMed”, “Science Direct” etc. These databases and search engines used here perform the limited criteria of search to conduct a systematic literature survey for the study and report writing. All the text from the articles and research papers were studied and analyzed. The various articles and research papers were used in writing this report and all of which are mentioned in the reference section of this report.

Conclusion

Our current studies reveal that nanoparticles may prove very helpful in the delivery of drugs for Covid-19 treatment. Many cases showed that patients, where drugs are delivered with the help of nanoparticles, produced very few side effects.

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.

Folate-methotrexate loaded bovine serum albumin nanoparticles preparation: an in vitro drug targeting cytokines overwhelming expressed immune cells from rheumatoid arthritis patients

The study planned to estimate biological parameters linked to rheumatoid arthritis (RA) patients, detecting the influence of MTX and biotherapy treatments on these parameters and synthesizing methotrexate bovine serum albumin nanoparticles linked to folate (FA-MTX-BSA NPs) to reduce the overwhelming expression of inflammatory cytokines. Inflammatory parameters showed significant increases in newly diagnosed and MTX-receiving groups while no changes were observed in the biotherapy-maintained group. MTX-loaded BSA nanoparticles were fabricated by the desolvation method and further linked to activated folic acid to obtain FA-MTX-BSA NPs. FA-MTX-BSA NPs were successfully characterized within the nanoscale range using different screening techniques. FA-MTX-BSA NPs showed an in vitro release in a sustained manner. The potential of MTX, MTX-BSA NPs, and FA-MTX-BSA NPs in inducing cytokine level reduction was detected. Significant decreases in interleukin- 1 beta (IL-1β), interleukin-6 (IL-6), and tumor necrosis factor-alpha (TNF-α) levels were obtained in cultures treated with FA-MTX-BSA NPs compared to the untreated culture in a dose-dependent pattern. Furthermore, FA-MTX-BSA NPs comparing with MTX and MTX-BSA NPs exhibited a significant advanced effect in decreasing cytokines levels. Accordingly, the conjunction of BSA NPs and MTX linked to folate potentially reduced cytokines manifestation in RA.

Hyaluronic-Coated Albumin Nanoparticles for the Non-Invasive Delivery of Apatinib in Diabetic Retinopathy

Purpose

Apatinib (Apa) is a novel anti-vascular endothelial growth factor with the potential to treat diabetic retinopathy (DR); a serious condition leading to visual impairment and blindness. DR treatment relies on invasive techniques associated with various complications. Investigating topical routes for Apa delivery to the posterior eye segment is thus promising but also challenging due to ocular barriers. Hence, the study objective was to develop Apa-loaded bovine serum albumin nanoparticles (Apa-BSA-NPs) coated with hyaluronic acid (HA); a natural polymer possessing unique mucoadhesive and viscoelastic features with the capacity to actively target CD44 positive retinal cells, for topical administration in DR.

Methods

Apa-BSA-NPs were prepared by desolvation using glutaraldehyde for cross-linking. HA-coated BSA-NPs were also prepared and HA: NPs ratio optimized. Nanoparticles were characterized for colloidal properties, entrapment efficiency (EE%), in vitro drug release and mucoadhesive potential. In vitro cytotoxicity on rabbit corneal epithelial cells (RCE) was assessed using MTT assay, while efficacy was evaluated in vivo in a diabetic rat model by histopathological examination of the retina by light and transmission electron microscopy. Retinal accumulation of fluorescently labeled BSA-NP and HA-BSA-NP was assessed using confocal microscope scanning.

Results

Apa-HA-BSA-NPs prepared under optimal conditions showed size, PdI and zeta potential: 222.2±3.56 nm, 0.221±0.02 and -37.3±1.8 mV, respectively. High EE% (69±1%), biphasic sustained release profile with an initial burst effect and mucoadhesion was attained. No evidence of cytotoxicity was observed on RCE cells. In vivo histopathological studies on DR rat model revealed alleviated retinal micro- and ultrastructural changes in the topical HA-Apa-BSA-NP treated eyes with normal basement membrane and retinal thickness comparable to normal control and intravitreally injected nanoparticles. Improved retinal accumulation for HA-BSA-NP was also observed by confocal microscopy.

Conclusion

Findings present HA-Apa-BSA-NPs as a platform for enhanced topical therapy of DR overcoming the devastating ocular complications of the intravitreal route.

The Uniqueness of Albumin as a Carrier in Nanodrug Delivery

Albumin is an appealing carrier in nanomedicine because of its unique features. First, it is the most abundant protein in plasma, endowing high biocompatibility, biodegradability, nonimmunogenicity, and safety for its clinical application. Second, albumin chemical structure and conformation allows interaction with many different drugs, potentially protecting them from elimination and metabolism in vivo, thus improving their pharmacokinetic properties. Finally, albumin can interact with receptors overexpressed in many diseased tissues and cells, providing a unique feature for active targeting of the disease site without the addition of specific ligands to the nanocarrier. For this reason, albumin, characterized by an extended serum half-life of around 19 days, has the potential of promoting half-life extension and targeted delivery of drugs. Therefore, this article focuses on the importance of albumin as a nanodrug delivery carrier for hydrophobic drugs, taking advantage of the passive as well as active targeting potential of this nanocarrier. Particular attention is paid to the breakthrough NAB-Technology, with emphasis on the advantages of Nab-Paclitaxel (Abraxane), compared to the solvent-based formulations of Paclitaxel, i.e., CrEL-paclitaxel (Taxol) in a clinical setting. Finally, the role of albumin in carrying anticancer compounds is depicted, with a particular focus on the albumin-based formulations that are currently undergoing clinical trials. The article sheds light on the power of an endogenous substance, such as albumin, as a drug delivery system, signifies the importance of the drug vehicle in drug performance in the biological systems, and highlights the possible future trends in the use of this drug delivery system.

Fabrication and characterization of sunflower protein isolate nanoparticles, and their potential for encapsulation and sustainable release of curcumin

In this research, first, the effects of two desolvating agents (ethanol and methanol) at three temperature values (4, 25, and 50 °C) on the fabrication of sunflower protein isolate (SnPI) nanoparticles were studied using a desolvation method. Second, the ability of the nanoparticles to encapsulate curcumin was investigated. Results showed that ethanol led to smaller nanoparticles compared to methanol as the desolvating agent at 4 and 50 °C. However, at 25 °C, ethanol formed the most uniform nanoparticles with the lowest polydispersity index (0.188 ± 0.091) and particle size of 174.64 ± 30.61 nm. The encapsulation efficiency was in the range of 39.1 to 95.4% according to the fabrication condition and curcumin-to-protein mass ratio. A biphasic trend of curcumin release from nanoparticles was observed; in which, over 50% of curcumin was released from the curcumin-loaded nanoparticles in the first 2 h, which is attributed to the burst effect of the protein matrix.

Measuring the concentration of protein nanoparticles synthesized by desolvation method: Comparison of Bradford assay, BCA assay, hydrolysis/UV spectroscopy and gravimetric analysis

The desolvation technique is one of the most popular methods for preparing protein nanoparticles for medicine, biotechnology, and food applications. We fabricated 11 batches of BSA nanoparticles and 2 batches of gelatin nanoparticles by desolvation method. BSA nanoparticles from 2 batches were cross-linked by heating at +70 °C for 2 h; other nanoparticles were stabilized by glutaraldehyde. We compared several analytical approaches to measuring their concentration: gravimetric analysis, bicinchoninic acid assay, Bradford assay, and alkaline hydrolysis combined with UV spectroscopy. We revealed that the cross-linking degree and method of cross-linking affect both Bradford and BCA assay. Direct measurement of protein concentration in the suspension of purified nanoparticles by dye-binding assays can lead to significant (up to 50-60%) underestimation of nanoparticle concentration. Quantification of non-desolvated protein (indirect method) is affected by the presence of small nanoparticles in supernatants and can be inaccurate when the yield of desolvation is low. The reaction of cross-linker with protein changes UV absorbance of the latter. Therefore pure protein solution is an inappropriate calibrator when applying UV spectroscopy for the determination of nanoparticle concentration. Our recommendation is to determine the concentration of protein nanoparticles by at least two different methods, including gravimetric analysis.

Influence of bound dodecanoic acid on the reconstitution of albumin nanoparticles from a lyophilized state

The development of reference standards for nanoparticle sizing allows for cross laboratory studies and effective transfer of particle sizing methodology. To facilitate this, these reference standards must be stable upon long-term storage. Here, we examine factors that influence the properties of cross-linked albumin nanoparticles, fabricated with an ethanol desolvation method, when reconstituted from a lyophilized state. We demonstrate, with nanoparticle tracking analysis, no significant changes in mean particle diameter upon reconstitution of albumin nanoparticles fabricated with bovine serum albumin loaded with dodecanoic acid, when compared to nanoparticles fabricated with a fatty acid-free BSA. We attribute this stability to the modulation of nanoparticle charge-charge interactions at dodecanoic acid specific binding locations. Furthermore, we demonstrate this in a lyophilized state over six months when stored at − 80 °C. We also show that the reconstitution process is readily transferable between technicians and laboratories and further confirm our finding with dynamic light scattering analysis.

Protein and Peptide Nanocluster Vaccines

Recombinant protein- and peptide-based vaccines can deliver large amounts of specific antigens for tailored immune responses. One class of these are protein and peptide nanoclusters (PNCs), which are made entirely from the crosslinked antigen. PNCs leverage the inherent immunogenicity of nanoparticulate antigens while minimizing the use of excipients normally used to create them. In this chapter, we discuss PNC fabrication methods, immunostimulatory properties of nanoclusters observed in vitro and in vivo, and protective benefits of PNC vaccines against influenza and cancer mouse models. We conclude with an outlook on future studies of PNCs and PNC design strategies, as well as their use in future vaccine formulations.

Protein Nanoparticle Charge and Hydrophobicity Govern Protein Corona and Macrophage Uptake

Protein nanoparticles are biomaterials composed entirely of proteins, with the protein sequence and structure determining the nanoparticle physicochemical properties. Upon exposure to physiological or environmental fluids, it is likely that protein nanoparticles, like synthetic nanoparticles, will adsorb proteins and this protein corona will be dependent on the surface properties of the protein nanoparticles. As there is little understanding of this phenomenon for engineered protein nanoparticles, the purpose of this work was to create protein nanoparticles with variable surface hydrophobicity and surface charge and establish the effect of these properties on the mass and composition of the adsorbed corona, using the fetal bovine serum as a model physiological solution. Albumin, cationic albumin, and ovalbumin cross-linked nanoparticles were developed for this investigation and their adsorbed protein coronas were isolated and characterized by gel electrophoresis and nanoliquid chromatography mass spectrometry. Distinct trends in corona mass and composition were identified for protein nanoparticles based on surface charge and surface hydrophobicity. Proteomic analyses revealed unique protein corona patterns and identified distinct proteins that are known to affect nanoparticle clearance in vivo. Further, the protein corona influenced nanoparticle internalization in vitro in a macrophage cell line. Altogether, these results demonstrate the strong effect protein identity and properties have on the corona formed on nanoparticles made from that protein. This work builds the foundation for future study of protein coronas on the wide array of protein nanoparticles used in nanomedicine and environmental applications.

Combination Therapy with Doxorubicin-Loaded Reduced Albumin Nanoparticles and Focused Ultrasound in Mouse Breast Cancer Xenografts

Because chemotherapeutic drugs are often associated with serious side effects, the central topic in modern drug delivery is maximizing the localization of drugs at the target while minimizing non-specific drug interactions at unwanted regions. To address this issue, biocompatible nanoparticles have been developed to enhance the drug half-life while minimizing the associated toxicity. Nevertheless, relying solely on the enhanced half-life and enhanced permeability and retention (EPR) effects has been ineffective, and designing stimulus-sensitive nanoparticles to introduce the precise control of drug release has been desired. In this paper, we introduce a pH-sensitive, reduced albumin nanoparticle in combination with focused ultrasound treatment. Not only did these nanoparticles have superior therapeutic efficacy and toxicity profiles when compared to the free drugs in xenograft mouse models, but we were also able to show that the albumin nanoparticles reported in this paper were more suitable than other types of non-reduced albumin nanoparticles as vehicles for drug delivery. As such, we believe that the albumin nanoparticles presented in this paper with desirable characteristics including the induction of strong anti-tumor response, precise control, and superior safety profiles hold strong potential for preclinical and clinical anticancer therapy.

Characterization of Bovine Lactoferrin Nanoparticle Prepared by Desolvation Technique

Lactoferrin (Lf) nanoparticles have been developed as a carrier of drugs and gene. Two main methods, desolvation technique and emulsification method, for preparation of protein nanoparticles have been reported so far, but most of the previous reports of Lf nanoparticles preparation are limited to emulsification method. In this study, we investigated the optimal conditions by desolvation technique for the preparation of glutaraldehyde-crosslinked bovine Lf (bLf) nanoparticles within the size range of 100-200 nm, and evaluated their properties as a carrier for oral and intravenous drug delivery. The experimental results of dynamic light scattering and Transmission Electron Microscope suggested that glutaraldehyde-crosslinked bLf nanoparticles with 150 nm in size could be produced by addition of 2-propanol as the desolvating solvent into the bLf solution adjusted to pH 6, followed by crosslinking with glutaraldehyde. These cross-linked bLf nanoparticles were found to be compatible to blood components and resistant against rapid degradation by pepsin. Thus, cross-linked bLf nanoparticles prepared by desolvation technique can be applied as a drug carrier for intravenous administration and oral delivery.

Characterization of a new small-molecule inhibitor of HDAC6 in glioblastoma

Histone deacetylase 6 (HDAC6) is an epigenetic modifier that is an attractive pharmacological target in cancer. In this work, we show that HDAC6 is elevated in glioblastoma, the most malignant and common brain tumor in adults, in which its high levels correlate with poor patient survival and is more abundant in glioma stem cell subpopulation. Moreover, we identified a new small-molecule inhibitor of HDAC6, which presents strong sensitivity for HDAC6 inhibition and exerts high cytotoxic activity, alone or in combination with temozolomide. It is also able to significantly reduce tumor growth in vivo. Transcriptomic analysis of patient-derived glioma stem cells revealed an increase in cell differentiation and cell death pathways, as well as a decrease in cell-cycle activity and cell division by the treatment with the compound. Finally, the comparison with a pan-HDAC inhibitor, Vorinostat (SAHA), or HDAC6-specific inhibitor, Tubastatin A, showed higher target specificity and antitumor activity of the new HDAC6 inhibitor. In conclusion, our data reveal the efficacy of a novel HDAC6 inhibitor in glioblastoma preclinical setting.

Polyelectrolytic BSA nanoparticles containing silicon dihydroxide phthalocyanine as a promising candidate for drug delivery systems for anticancer photodynamic therapy

Recently several scientific-technological advances in the health area have developed. Among them, we can highlight research addressing nanoscience and nanotechnology focusing on the development of formulations for the cancer treatment. This work describes the synthesis and characterization of bovine serum albumin (BSA) polyelectrolytic nanoparticles for controlled release using silicon dihydroxide phthalocyanine [SiPc (OH)₂] as a photosensitizer model for application in Photodynamic Therapy (PDT). BSA nanoparticles were prepared by the one-step desolvation process and the nanoparticulate system was coated with polyelectrolytes using poly-(4-styrene sulfonate - PSS) as a strong polyanion and polyallylamine hydrochloride (PAH) as a weak polycation by the technique self-assembling layer-by-layer (LbL). The formulation was characterized and available in cellular culture. The profile of drug release was investigated and compared to that of free [SiPc (OH)₂]. The nanoparticles have a mean diameter of 226.9 nm, a narrow size distribution with polydispersive index of 0.153, smooth surface and spherical shape. [SiPc(OH)₂] loaded nanoparticles maintain its photophysical behaviour after encapsulation. The polyelectrolytic nanoparticles improved efficiency in release and photocytotoxicity assay when compared to pure drug. The results demonstrate that photosensitizer adsorption on BSA nanoparticles together with biopolymer layer-by-layer assembly provides a way to manufacture biocompatible nanostructured materials that are intended for use as biomaterials for Photodynamic Therapy applications.

Synthesis and characterisation of aqueous haemoglobin-based microcapsules coated by genipin-cross-linked albumin

Bovine serum albumin (BSA)-coated haemoglobin (Hb)-microcapsules prepared by co-precipitation of Hb and MnCO₃ may present an alternative type of artificial blood substitute. Prepared microcapsules were analysed by Scanning electron microscopy (SEM) and Respirometry, cytotoxicity was evaluated by addition of microcapsules to murine fibroblast-derived cell line L929 (American Type Culture Collection, NCTC clone 929 of strain L). The capsules come along with a mean diameter of approximately 0.6 μm and a mean volume of 1.13 × 10^-19 L, thus an average human red blood cell with a volume of 9 × 10^-14 L is about 800,000 times bigger. Hb-microcapsules are fully regenerable by ascorbic acid and maintain oxygen affinity because oxygen is able to pass the BSA wall of the capsules and thereby binding to the ferrous iron of the haemoglobin entity. Therefore, these microcapsules present a suitable type of potential artificial haemoglobin-based oxygen carrier (HbOC).

Albumin nanoscience: homing nanotechnology enabling targeted drug delivery and therapy

Albumin is a biocompatible, non-immunogenic and versatile drug carrier system. It has been widely used to extend the half-life, enhance stability, provide protection from degradation and allow specific targeting of therapeutic agents to various disease states. Understanding the role of albumin as a drug delivery and distribution system has increased remarkably in the recent years from the development of albumin-binding prodrugs to albumin as a drug carrier system. The extraordinary surface property of albumin makes it possible to bind various endogenous and exogenous molecules. This review succinctly deals with several albumin-drug conjugates and nanoparticles along with their preparation techniques and focuses on surface-modified albumin and targeting of albumin formulation to specific organs and tissues. It also summarizes research efforts on albumin nanoparticles used for delivering drugs to tumor cells and describes their role in permeation through tumor vasculature and in receptor mediated endocytosis, which is also described in this review. The versatility of albumin and ease of preparation makes it a suitable drug carrier system, swhich is the major objective of this review.

Advances in nanotechnology-based delivery systems for EGFR tyrosine kinases inhibitors in cancer therapy

Oral tyrosine kinase inhibitors (TKIs) against epidermal growth factor receptor (EGFR) family have been introduced into the clinic to treat human malignancies for decades. Despite superior properties of EGFR-TKIs as small molecule targeted drugs, their applications are still restricted due to their low solubility, capricious oral bioavailability, large requirement of daily dose, high binding tendency to plasma albumin and initial/acquired drug resistance. Nanotechnology is a promising tool to improve efficacy of these drugs. Through non-oral routes. Various nanotechnology-based delivery approaches have been developed for providing efficient delivery of EGFR-TKIs with a better pharmacokinetic profile and tissue-targeting ability. This review aims to indicate the advantage of nanocarriers for EGFR-TKIs delivery.

Folate Receptor-Targeted Albumin Nanoparticles Based on Microfluidic Technology to Deliver Cabazitaxel

Microfluidic technology (MF) has improved the formulation of nanoparticles (NPs) by achieving uniform particle size distribution, controllable particle size, and consistency. Moreover, because liquid mixing can be precisely controlled in the pores of the microfluidic chip, maintaining high mixing efficiency, MF exerts higher of NP encapsulation efficiency (EE) than conventional methods. MF-NPs-cabazitaxel (CTX) particles (MF-NPs-CTX) were first prepared by encapsulating CTX according to MF. Folate (FA)- Polyethylene glycol (PEG)-NPs-CTX particles (FA-PEG-NPs-CTX) were formulated by connecting FA to MF-NPs-CTX to endow NPs with targeted delivery capability. Accordingly, the mean particle size of FA-PEG-NPs-CTX increased by approximately 25 nm, as compared with MF-NPs-CTX. Upon morphological observation of FA-PEG-NPs-CTX and MF-NPs-CTX by transmission electron microscopy (TEM), all NPs were spherical and particle size distribution was uniform. Moreover, the increased delivery efficiency of CTX in vitro and its strong tumor inhibition in vivo indicated that FA-PEG-NPs-CTX had a powerful tumor-suppressive effect both in vitro and in vivo. In vivo imaging and pharmacokinetic data confirmed that FA-PEG-NPs-CTX had good drug delivery efficiency. Taken together, FA-PEG-NPs-CTX particles prepared using MF showed high efficient and targeted drug delivery and may have a considerable driving effect on the clinical application of targeting albumin NPs.

Intracellular nanoparticle delivery by oncogenic KRAS-mediated macropinocytosis

Background

The RAS family of oncogenes (KRAS, HRAS, NRAS) are the most frequent mutations in cancers and regulate key signaling pathways that drive tumor progression. As a result, drug delivery targeting RAS-driven tumors has been a long-standing challenge in cancer therapy. Mutant RAS activates cancer cells to actively take up nutrients, including glucose, lipids, and albumin, via macropinocytosis to fulfill their energetic requirements to survive and proliferate.

Purpose

We exploit macropinocytosis pathway to deliver nanoparticles (NPs) in cancer cells harboring activating KRAS mutations.

Methods

NPs were synthesized by the desolvation method. The physicochemical properties and stability of NPs were characterized by dynamic light scattering and transmission electron microscopy. Uptake of fluorescently labelled NPs in wild-type and mutant KRAS cells were quantitively determined by flow cytometry and qualitatively by fluorescent microscopy. NP uptake by KRAS-driven macropinocytosis was confirmed by pharmacological inhibition and genetic knockdown.

Results

We have synthesized stable albumin NPs that demonstrate significantly greater uptake in cancer cells with activating mutations of KRA S than monomeric albumin (ie, dissociated form of clinically used nab-paclitaxel). From pharmacological inhibition and semi-quantitative fluorescent microscopy studies, these NPs exhibit significantly increased uptake in mutant KRAS cancer cells than wild-type KRAS cells by macropinocytosis.

Conclusions

The uptake of albumin nanoparticles is driven by KRAS. This NP-based strategy targeting RAS-driven macropinocytosis is a facile approach toward improved delivery into KRAS-driven cancers.

Magnetically controlled protein nanocontainers as a drug depot for the hemostatic agent

PURPOSE

Currently, there is a number of successfully implemented local hemostatic agents for external bleedings in forms of wound dressings and other topical materials. However, little has been done in the field of intravenous hemostatic agents. Here, we propose a new procedure to fabricate biocompatible protein nanocontainers (NCs) for intravenous injection allowing magneto-controllable delivery and short-term release of the hemostatic agent ε-aminocaproic acid (EACA).

METHODS

The nanocontainers were synthesized by the desolvation method from bovine serum albumin (BSA) using methanol without any further crosslinking. Polyethylene glycol (PEG) was used both as a stabilization agent and for size control. Characterization of nanocontainers was performed by the transmission and scanning electron microscopy, dynamic light scattering, X-ray diffraction, and FTIR spectroscopy. Cytotoxicity was estimated using MTT assay. The dopant release from nanocontainers was measured spectrophotometrically using rhodamine B as a model molecule. The specific hemostatic activity was assessed by analyzing clot lysis and formation curve (CloFAL). Moreover, the ability for magneto targeting was estimated using the original flow setup made of a syringe pump and silicon contours.

RESULTS

Fabricated nanocontainers had an average size of 186±24 nm and were constructed from building blocks-nanoparticles with average size ranged from 10 to 20 nm. PEG shell was also observed around nanocontainers with thickness 5-10 nm. NCs were proved to be completely non-cytotoxic even at concentrations up to 8 mg BSA/mL. Uptake capacity was near 36% while release within the first day was 17%. The analysis of the CloFAL curve showed the ability of NCs to inhibit the clot lysis successfully, and the ability of magneto targeting was confirmed under flow conditions.

CONCLUSION

The ability of synthesized NCs to deliver and release the therapeutic drug, as well as to accumulate at the desired site under the action of the magnetic field was proved experimentally.

Gold nanocluster-loaded hybrid albumin nanoparticles with fluorescence-based optical visualization and photothermal conversion for tumor detection/ablation

Gold nanoclusters (AuNCs) are viewed as effective hyperthermal agents for the treatment of tumors. Whereas AuNCs formed by the agglomeration of several to tens of gold atoms (<1-2 nm) possess significant fluorescence, they have a negligible hyperthermal effect, while AuNCs comprised of spherical gold nanoparticles (AuNPs > a few nanometers) have a marked hyperthermic effect but lose their inherent fluorescence and obstruct the intensity of neighboring fluorescent dyes due to Forster resonance energy transfer (FRET). To achieve both hyperthermia and fluorescence-based optical visualization, we generated hybrid albumin nanoparticles containing AuNCs (~88 nm) comprising AuNPs (~4.5 nm). We generated a series of formulated AuNCs and optimized the size, morphology, NIR absorbance (600-900 nm), hyperthermal activity, and fluorescence spectral characters of the resulting hybrid albumin nanoparticles (AuNCs/BSA-NPs) by considering the interparticle distance between the AuNPs and Cy5.5. Among these, AuNCs/BSA-NPs (formula D) had a strong hyperthermic effect and had well-preserved fluorescence intensity (from the attached Cy5.5) due to localized surface plasmon resonance (LSPR) and a reduction in FRET. These AuNCs/BSA-NPs were able to elevate the surface tumor temperature of HCT116-bearing mice to >50 °C following 808 nm laser irradiation (1.5 W/cm², 10 min), which remarkably suppressed tumor growth (17.8 ± 16.9 mm³vs. PBS and AuNCs/BSA-NPs (formula E): ~1850 and ~1250 mm³, respectively). Also, Cy5.5-modified AuNCs/BSA-NPs (formula D) showed good performance in optical fluorescence imaging of target tumors in HCT116 tumor-bearing mice. Together, our results indicate that the interparticle distance between albumin or Cy5.5 and AuNPs/AuNCs can be optimized to achieve both hyperthermia and fluorescence emission by striking a balance between LSPR and FRET effects. We believe that the AuNC/BSA-NPs formulation presented here can serve as a potential platform for both optically visualizing and treating colon cancers.