Self-assembled nanoparticles of costunolide and glycyrrhizic acid for enhanced ulcerative colitis treatment.

Ulcerative colitis (UC) is a persistent inflammatory condition that specifically targets the colon and rectum. Existing therapies fail to adequately address the clinical requirements of people suffering from this ailment. Despite the acknowledged potential of nanomedicines in the field of anti-inflammatory treatment, their widespread use in clinical settings is impeded by their expensive nature and the uncertainty surrounding their safety profiles. This study illustrates that two naturally occurring phytochemicals, Costunolide (COS) and Glycyrrhizic acid (GA), form carrier-free, multifunctional spherical nanoparticles (NPs) through noncovalent interactions, such as π-π stacking and hydrogen bonding. The COS-GA NPs displayed a synergistic anti-inflammatory effect, providing much more evidently improved therapeutic benefits for dextran sodium sulfate (DSS)-induced UC mice due to more effective reduction in inflammation and oxidative stress than did equal dosages of COS or GA used alone. In addition, COS-GA NPs have biocompatibility and biosafety properties unique to them. This study will serve as affirmation of the potential of COS-GA NPs as innovative natural anti-inflammatory and antioxidant activities and also such agents as drug discovery in UC, leading possibly to better outcomes in people living with this disabling condition.

Recognition on pharmacodynamic ingredients of natural products.

Natural products (NPs) play an irreplaceable role in the intervention of various diseases and have been considered a critical source of drug development. Many new pharmacodynamic compounds with potential clinical applications have recently been derived from NPs. These compounds range from small molecules to polysaccharides, polypeptides, proteins, self-assembled nanoparticles, and extracellular vesicles. This review summarizes various active substances found in NPs. The investigation of active substances in NPs can potentiate new drug development and promote the in-depth comprehension of the mechanism of action of NPs that can be beneficial in the prevention and treatment of human diseases.

Synthesis and Characterization of Nanoparticle-Based Dexamethasone-Polypeptide Conjugates as Potential Intravitreal Delivery Systems.

The use of dexamethasone for eye disease treatment is limited by its low solubility, bioavailability, and rapid elimination when applied topically. The covalent conjugation of dexamethasone with polymeric carriers is a promising strategy to overcome existing drawbacks. In this work, amphiphilic polypeptides capable of self-assembly into nanoparticles were proposed as potential delivery systems for intravitreal delivery. The nanoparticles were prepared and characterized using poly(L-glutamic acid-co-D-phenylalanine) and poly(L-lysine-co-D/L-phenylalanine) as well as poly(L-lysine-co-D/L-phenylalanine) covered with heparin. The critical association concentration for the polypeptides obtained was in the 4.2-9.4 µg/mL range. The hydrodynamic size of the formed nanoparticles was between 90 and 210 nm, and they had an index of polydispersity between 0.08 and 0.27 and an absolute zeta-potential value between 20 and 45 mV. The ability of nanoparticles to migrate in the vitreous humor was examined using intact porcine vitreous. Conjugation of DEX with polypeptides was performed by additional succinylation of DEX and activation of carboxyl groups introduced to react with primary amines in polypeptides. The structures of all intermediate and final compounds were verified by 1H NMR spectroscopy. The amount of conjugated DEX can be varied from 6 to 220 µg/mg of polymer. The hydrodynamic diameter of the nanoparticle-based conjugates was increased to 200-370 nm, depending on the polymer sample and drug loading. The release of DEX from the conjugates due to hydrolysis of the ester bond between DEX and the succinyl moiety was studied both in a buffer medium and a vitreous/buffer mixture (50/50, v/v). As expected, the release in the vitreous medium was faster. However, the release rate could be controlled in the range of 96-192 h by varying the polymer composition. In addition, several mathematical models were used to assess the release profiles and figure out how DEX is released.

Solubilization mechanism of self-assembled walnut protein nanoparticles and curcumin encapsulation.

BACKGROUND: Native walnut protein is an alkali-soluble protein that seriously limits the application of walnut protein. The pH-shifting method could improve the solubility of walnut proteins and enable the encapsulation of active ingredients. The present study aimed to prepare water-soluble nanoparticles of curcumin using walnut protein and evaluate the process of walnut protein self-assembly, interaction between walnut protein and curcumin, encapsulation properties, and stability of nanoparticles. RESULTS: The solubility of native walnut protein was poor, but the solubility of walnut protein nanoparticles (WPNP) formed by walnut protein after pH-shifting significantly improved to 91.5 ± 1.2%. This is because, during the process of pH changing from 7 to 12 and back to 7, walnut protein first unfolded under alkaline conditions and then refolded under pH drive, finally forming an internal hydrophobic and external hydrophilic shell-core structures. The quenching type of walnut protein and curcumin was static quenching, and the quenching constant was 2.0 × 1014 mol-1 L-1 s-1 , indicating that the interaction between walnut protein and curcumin was non-covalent. Adding curcumin resulted in the formation of nanoparticles with small particle size compared with the no-load. The loading capacity of curcumin-loaded walnut protein nanoparticles (WPNP-C) was 222 mg g-1 walnut protein isolate. Under the same mass, the curcumin equivalent concentration in aqueous solution of WPNP-C was 17 000 times higher than that of the native curcumin. CONCLUSION: The solubility of the self-assembled WPNP significantly increased after pH-shifting treatment. The walnut protein carrier could improve the stability of the encapsulated curcumin. Therefore, walnut proteins could be used as water-soluble carriers for hydrophobic drugs. © 2023 Society of Chemical Industry.

[Separation, characterization and anti-psoriasis effect of self-assembled nanoparticles from Shaoyao Gancao Decoction].

This study aims to separate and characterize self-assembled nanoparticles(SAN) from Shaoyao Gancao Decoction(SGD) and determine the content of active compounds. Further, we aimed to observe the therapeutic effect of SGD-SAN on imiquimod-induced psoriasis in mice. The separation of SGD was performed by dialysis, and the separation process was optimized by single factor experiment. The SGD-SAN isolated under the optimal process was characterized, and the content of gallic acid, albiflorin, paeoniflorin, liquiritin, isoliquiritin apioside, isoliquiritin, and glycyrrhizic acid in each part of SGD was determined by HPLC. In the animal experiment, mice were assigned into a normal group, a model group, a methotrexate group(0.001 g·kg~(-1)), and SGD, SGD sediment, SGD dialysate, and SGD-SAN groups of different doses(1, 2, and 4 g·kg~(-1)) respectively. The psoriasis grade of mice was evaluated based on the pathological changes of skin lesions, the content of inflammatory cytokines, organ index and other indicators. The results showed that SAN obtained by centrifugation at 13 000 r·min~(-1) for 30 min was stable after dialysis for 4 times, which were uniform spherical nanoparticles with the particle size of(164.43±1.34) nm, the polydispersity index of(0.28±0.05), and the Zeta potential of(-12.35±0.80) mV. The active compound content accounted for more than 70% of SGD. Compared with the model group, SAN and SGD decreased the skin lesion score, spleen index, and inflammatory cytokine levels(P<0.05 or P<0.01) and alleviated the skin thickening and infiltration of inflammatory cells. However, the sediment group and the dialysate group had no obvious effect. SGD showed a good therapeutic effect on imiquimod-induced psoriasis in mice, and SAN demonstrated the effect equivalent to SGD in a dose-dependent manner. Therefore, we conclude that the SAN formed during decocting is the main active form of SGD, which can lower the levels of inflammatory cytokines, promote the normal differentiation of keratinocytes, and reduce the infiltration of inflammatory cells in the treatment of psoriasis lesions in mice.

Fabrication of self-assembled peptide nanoparticles for in vitro assessment of cell apoptosis pathway and in vivo therapeutic efficacy.

Near-infrared fluorescent (NIRF) dye-coupled self-assembled RGD-linked proapoptotic peptide nanoparticles have been synthesized with spherical shape and size ~ 30-40 nm diameters. The peptide sequence was coupled with cyanine 5.5 probe as NIRF-dye to introduce optical imaging properties and pH-dependent method was used to design Cy5.5 coupled self-assembled peptide nanoparticles (f-SAPNs). This nanoprobe has the ability to target αvß3-integrin receptor overexpressed on cancer cell's surface with improved internalization capabilities into the mitochondria. The in situ study showed that this peptide sequence has potential to disrupt the mitochondrial membrane efficiently, activating the Caspase-3 enzyme, and ultimately induces cell apoptosis. It has been observed from in vitro study that the degree of apoptosis for f-SAPNs was increased from 25.6% to 96.3%, while decreased degree of necrosis from 51.7% to 0.2% compared with its parent peptide analog (Cy5.5-c[RGDKLAK]; f-CP) occurs. Further investigations revealed that these f-SAPNs showed high uptake in U87MG glioblastoma cells in comparison with PC-3 prostate cancer cells. Moreover, in vivo therapeutic studies represented the prominent decrease in the size of tumor tissue treated with f-CP and f-SAPNs (201 ± 13 mm3 and 104 ± 6 mm3, respectively) compared with untreated tumor tissues (366 ± 18 mm3). These outcomes highlighted the specificity, and efficacy of f-SAPNs toward αvß3-integrin expressing tumor tissue in vivo and suggested that these novel designed f-SAPNs may serve as a potential theranostic drug for brain tumor glioblastoma multiforme. The pH-sensitive method gives NIRF dye-coupled self-assembled peptide nanoparticle (f-SAPNs), enables the tunable synthesis of spherical nanoparticles with high stability towards proteolysis, improved biocompatibility, and promising therapeutic efficacy.

Cannabidiol as Self-Assembly Inducer for Anticancer Drug-Based Nanoparticles.

Cannabidiol (CBD) is a biologically active compound present in the plants of the Cannabis family, used as anticonvulsant, anti-inflammatory, anti-anxiety, and more recently, anticancer drug. In this work, its use as a new self-assembly inducer in the formation of nanoparticles is validated. The target conjugates are characterized by the presence of different anticancer drugs (namely N-desacetyl thiocolchicine, podophyllotoxin, and paclitaxel) connected to CBD through a linker able to improve drug release. These nanoparticles are formed via solvent displacement method, resulting in monodisperse and stable structures having hydrodynamic diameters ranging from 160 to 400 nm. Their biological activity is evaluated on three human tumor cell lines (MSTO-211H, HT-29, and HepG2), obtaining GI50 values in the low micromolar range. Further biological assays were carried out on MSTO-211H cells for the most effective NP 8B, confirming the involvement of paclitaxel in cytotoxicity and cell death mechanism.

Murine pharmacokinetics and antimalarial pharmacodynamics of dihydroartemisinin trimer self-assembled nanoparticles.

Currently, conjugation of artemisinin-derived dimers, trimers, and tetramers is a viable strategy for developing new effective antimalarial candidates. Furthermore, nanotechnology is an effective means to achieve intravenous administration of hydrophobic drugs. In this paper, an ester-linked dihydroartemisinin trimer (DHA3) was synthesized and further prepared as self-assembled nanoparticles (DHA3NPs) by a one-step nanoprecipitation method. The pharmacokinetics and antimalarial pharmacodynamics of DHA3NPs were studied in rats and mice infected with Plasmodium yoelii BY265 (PyBY265). DHA3NPs had a regular spherical shape with a uniform size distribution of 140.27 ± 3.59 nm, entrapment efficiency (EE) of 99.63 ± 0.17%, and drug loading efficiency (DL) of 79.62 ± 0.11%. The in vitro release characterization revealed that DHA3NPs were easily hydrolysed into DHA in an esterase environment. The pharmacokinetics study demonstrated that the area under the concentration-time curve (AUC0-t) of DHA in DHA3NPs group was 2070.52 ± 578.76 h×ng×mL-1, which was higher than that of DHA and artesunate (AS) control groups (AUC0-t values of 724.18 ± 94.32 and 448.40 ± 94.45 h×ng×mL-1, respectively) (P < 0.05). The antimalarial pharmacodynamics in vivo suggested that DHA3NPS (ED90 7.82 ± 1.16 µmol×(kg×day)-1) had a superior antimalarial effect compared with that of control groups (ED90 values of 14.68 ± 0.98 (DHA) and 14.34 ± 1.96 (AS) µmol×(kg×day)-1) (P < 0.05). In addition, DHA3NPS reduced the recurrence ratio and improved the cure ratio and survival time. In summary, DHA3NPs exhibited promising pharmacokinetic characteristics and antimalarial pharmacodynamics in vivo.

Transforming Complexity to Simplicity: Protein-Like Nanotransformer for Improving Tumor Drug Delivery Programmatically.

It was difficult for nanodrugs to simultaneously meet the contradictory requirements of prolonged circulation time, augmented cellular uptake, rapid lysosome escape, precise drug release, and tumor penetration in tumor drug delivery. We prepared a nanotransformer (DTIG) through assembling doxorubicin, tannic acid, and indocyanine green to overcome this dilemma. Hydrophilic DTIG showed prolonged blood circulation time. Besides, DTIG could be efficiently internalized by tumor cells through transforming into hydrophobic particles in an acidic tumor microenvironment. Subsequently, oversized hydrophobic particles were further formed in acidic lysosomes to escape from it through rupturing the lysosome. These hydrophobic DTIGs could rapidly revert to a smaller hydrophilic nanoassembly and release the payloads in cytoplasm. Similar to denaturation and renaturation of protein, these high-efficiency instantaneous transformations were activated by proton. Besides, photothermal therapy of DTIG promoted drug penetration efficiency in tumor. This optimized drug delivery process of DTIG finally offered potent antitumor efficacy and an obvious advantage on prognosis.

[Biofilm Eradication Four-Step Strategy: Study of Using Self-Assembled Azithromycin/Rhamnolipid Nanoparticles for Removing Pseudomonas aeruginosa Biofilm].

OBJECTIVE: To investigate the in vitro eradicative effect of self-assembled azithromycin/rhamnolipid nanoparticles (AZI-RHL NPs) on P seudomonas aeruginosa ( P. aeruginosa) biofilm. METHODS: AZI-RHL NPs were prepared and characterized. The minimum inhibitory concentration (MIC) of AZI-RHL NPs on planktonic P. aeruginosa was measured by the broth microdilution method. The eradicative effect of AZI-RHL NPs on P. aeruginosa biofilm was evaluated via crystal violet staining and SYTO 9/PI live/dead staining. Fluorescence labeling was used to measure the eradicative effect of NPs on extracellular polymeric substances (EPS). In addition, crystal violet staining was performed to evaluate the inhibitory effect of AZI-RHL NPs on the adhesion of P. aeruginosa on human bronchial epithelial BEAS-2B cells. To investigate the ability of AZI-RHL NPs to penetrate mucus, the interaction between NPs and mucin was measured via particle size changes after co-incubation with mucin solution. RESULTS: The AZI-RHL NPs had a particle size of about 121 nm and were negatively charged on the surface, displaying a high encapsulation efficiency and a high drug loading capacity of 96.72% and 45.08% for AZI, respectively and 99.38% and 53.07% for RHL, respectively. The MIC of AZI-RHL NPs on planktonic P. aeruginosa was half of that of using AZI alone. AZI-RHL NPs displayed the capacity to effectively destroy the biofilm structure and remove the proteins and polysaccharides in EPS, eradicating biofilms in addition to reducing the survival rate of bacteria in the biofilm. AZI-RHL NPs were shown to have inhibited P. aeruginosa adhesion on BEAS-2B cells and prevented the residual bacteria from forming a new biofilm. There was no significant change in the particle size of NPs after co-incubation with mucin solution, indicating a weak interaction between NPs and mucin, and suggesting that NPs could penetrate the mucus and reach the P. aeruginosa infection sites. CONCLUSION: AZI-RHL NPs were able to effectively enhance the removal of P. aeruginosa biofilm through a four-step strategy of biofilm eradication, including penetrating the mucus, disintegrating the biofilm structure, killing the bacteria dispersed from biofilm, and preventing the adhesion of residual bacteria. We hope that this study will provide a replicable common strategy for the treatment of refractory infections caused by P. aeruginosa and other types of biofilms.

[Advances in formation and application of self-assembled nanoparticles from traditional Chinese medicine].

Due to the diverse sources and unique structures, the chemical components of Chinese medicinal materials are easy to self-assemble to form nanoparticles. The formation of self-assembled nanoparticles(SAN) can not only affect the absorption and distribution of the effective ingredients in Chinese medicinal materials but also may improve the biological activity of the effective ingredients or their simple mixtures, which is of great significance for revealing the compatibility mechanism of Chinese medicine prescription, developing new Chinese medicine products, and producing new nanomaterials. This paper reviews the formation, isolation, characterization, and application of SAN of Chinese medicines, and discusses the problems and development trends of the relevant research, which can provide reference for the further study and promote the innovation and application of such SAN.

[Effect of self-assembled nanoparticles from Shaoyao Gancao Decoction on release and absorption of main components of Baishao].

To study the effect of self-assembled nanoparticles from Shaoyao Gancao Decoction(SGD-SAN) on the encapsulation, in vitro release and intestinal absorption of the main components of Baishao. Particle size analysis and morphological observation were used to verify the formation of SGD-SAN in the decoction. The entrapment efficiency(EE) of SGD-SAN on the main components of Baishao was determined by ultrafiltration centrifugation. The dialysis bag method was used to study the in vitro release of the main components of Baishao with pH 6.8 phosphate buffer solution as the release media. Single-pass intestinal perfusion study was performed to investigate the effect of SGD-SAN on the absorption of the main components of Baishao. The results showed that there were nanoparticles in the SGD, and the particle sizes and PDI of SGD-SAN were about 200 nm and 0.38, respectively. SGD-SAN was irregularly spherical under transmission electron microscope(TEM). The EEs of albiflorin, paeoniflorin and benzoylpaeoniflorin in SGD-SAN were 33.78%±1.03%,33.61%±0.90%,88.53%±0.58%, respectively. The release characteristics of albiflorin, paeoniflorin and benzoylpaeoniflorin from SGD-SAN showed a slow-release effect on pH 6.8 phosphate buffer solution media. SGD-SAN could significantly enhance the absorption of albiflorin, paeoniflorin and benzoylpaeoniflorin in the ileum. The results of this study indicated that SAN could be formed during the mixed decoction of Baishao and Gancao, and SGD-SAN could encapsulate the components of Baishao, with a certain slow-release effect, and the formation of SAN facilitated the absorption of drugs in the ileum.

Evaluation the synergistic antitumor effect of methotrexate-camptothecin codelivery prodrug from self-assembly process to acid-catalyzed both drugs release: A comprehensive theoretical study.

Therapeutic efficiency of amphiphilic methotrexate-camptothecin (MTX-CPT) prodrug compared to free drug mixture (MTX/CPT) has been investigated using all-atom molecular dynamics simulation and first principles density functional theory calculations. This comparison revealed that MTX-CPT prodrug tends to form spherical self-assembled nanoparticle (NP), while free MTX/CPT mixture forms rod-shape NP. These observations are attributed to a structural defect in the MTX-CPT prodrug and solvation free energies of MTX, CPT and MTX-CPT molecules. The results provided evidence that noncovalent interactions (NCIs) among the pharmaceutical drugs play a very important role in anticancer agents aggregation process, leading to enhanced stability of the self-assembled NPs. It is found that the stability of MTX-CPT self-assembled NP is greater than the MTX/CPT NP due to the synergistic effect of hydrogen bonding between monomers and solvent (water). Moreover, the noncatalyzed as well as catalyzed hydrolysis reactions of MTX-CPT prodrug are theoretically studied at the PCM(water)//M06-2X/6-31G(d,p) computational level to shed additional light on the role of acidic condition in tumor tissues. We found that the ester hydrolysis in mild acidic solutions is a concerted reaction. In an agreement between theory and experiment, we also confirmed that the activation energies of the catalyzed-hydrolysis steps are much lower than the activation energies of the corresponding steps in the noncatalyzed reaction. Thus, the MTX-CPT prodrug reveals very promising properties as a pH-controlled drug delivery system.

Drug-loaded titanium dioxide nanoparticle coated with tumor targeting polymer as a sonodynamic chemotherapeutic agent for anti-cancer therapy.

Sonodynamic therapy utilizes ultrasound (US)-responsive generation of reactive oxygen species (ROS) from sonosensitizer, and it is a powerful strategy for anti-cancer treatment in combination with chemotherapy. Herein, we report a precisely designed sonodynamic chemotherapeutics which exhibits US-responsive drug release via ROS generation from co-loaded sono-sensitizer. Doxorubicin (DOX)-coordinated titanium dioxide nanoparticles (TNPs) were encapsulated with polymeric phenyboronic acid (pPBA) via phenylboronic ester bond between pPBA and DOX. Loaded DOX was readily released under US irradiation due to the ROS-cleavable characteristics of phenylboronic ester bond. The size of nanoparticles was around 200 nm, and DOX was released by ROS generated under US irradiation. Tumor targeting by PBA moiety, intracellular ROS generation, and combined therapeutic effect against tumor cells were confirmed in vitro. Finally, we demonstrated high tumor accumulation and efficient tumor growth inhibition in tumor-bearing mice under US irradiation, which revealed potential as a multi-functional agent for sonodynamic chemotherapy.

Optimization of the Conditions for Plasmid DNA Delivery and Transfection with Self-Assembled Hyaluronic Acid-Based Nanoparticles.

Polymeric systems have been extensively studied as polyelectrolyte complexes to enhance the cellular delivery and transfection efficiency of genetic materials, such as plasmid DNA (pDNA). Here, self-assembled nanoparticles were formulated by complexation of hyaluronic acid (HA)-conjugated poly(ethylene glycol) (HA-PEG) and poly(ethylenimine) (HA-PEI), respectively, with pDNA creating relatively small, stable, and multifunctional nanoparticle complex formulations with high transfection efficiency. This formulation strategy offers high gene expression efficiency and negligible cytotoxicity in HeLa and A549 human lung cancer cell lines. To develop the ideal formulation, in vitro transfection efficiency was studied for three different nanoparticle formulations (HA-PEI/HA-PEG, HA-PEI, and HA-PEG) with different concentrations. The combination of the three polymers (HA, PEG, and PEI) was significant for the formulation to achieve the maximum gene expression results. The nanoparticles were found to be stable for up to a week at 4 °C conditions. Overall, these HA-based nanoparticles showed promising aspects that can be utilized in the designing of gene delivery vectors for cancer therapy.

5ß-Cholanic Acid/Glycol Chitosan Self-Assembled Nanoparticles (5ß-CHA/GC-NPs) for Enhancing the Absorption of FDs and Insulin by Rat Intestinal Membranes.

The absorption-enhancing effects of glycol chitosan modified by 5ß-cholanic acid nanoparticles (5ß-CHA/GC-NPs) on a drug with poor absorption in the intestine were studied by the method of in situ closed loop. We chose fluorescein isothiocyanate-labeled dextrans (FDs) and insulin as the model drugs. 5ß-CHA/GC-NPs loaded to different drugs were prepared by the dialysis method, and the physicochemical characteristics and in vitro release profiles of nanoparticles were also estimated. The results showed that 5ß-CHA/GC-NPs markedly increased the absorption of insulin and FDs in the jejunum, ileum, and colon. The ratios of absorption for all the drugs in the jejunum were higher than those in the ileum and colon. In addition, the enhancing effect of 5ß-CHA/GC-NPs for the absorption of FDs from the jejunum was decreased with increasing molecular weights. In the toxicity test, 5ß-CHA/GC-NPs did not significantly increase the release of protein and the activities of LDH, indicating that the nanoparticles did not cause any membrane damage to the intestine. These findings suggested that 5ß-CHA/GC-NPs were safe and useful carriers for enhancing the absorption of the drug with poor absorption by intestinal membranes.

Construction and cellular uptake evaluation of redox-responsive docetaxel prodrug self-assembled nanoparticles.

Docetaxel (DTX) solution has some serious adverse side effects. A redox-responsive DTX prodrug synthesized in our laboratory was used to prepare DTX prodrug self-assembled nanoparticles (DSNPs) with the method of nanoprecipitation. This study aimed at optimizing the formulation to develop stable preparation for the delivery of DTX. Single-factor test was used to evaluate the effects of the preparation concentration of DTX prodrug, stirring speed, the types of stabilizers and temperature on the prescription process of DSNPs. The particle size and polydispersity index were selected as the evaluation indexes. The entrapment efficiency, drug-loading, size distribution and zeta potential were characterized by UPLC and Zetasizer, respectively. The stability and cellular behavior of DSNPs were investigated by Zetasizer, LC-MS/MS and confocal laser scanning microscope, respectively. The particle size, entrapment efficiency and drug-loading of DSNPs were 173.8 ± 1.4 nm, 98.8% ± 0.1%, and 47.8% ± 0.9%, respectively. DSNPs showed good stability during the storage of 30 days, and were taken into the cells in a time-dependent and concentration-dependent manner. The method of nanoprecipitation could be used to entrap DTX. The preparation method was simple, and the quality of DSNPs was stable and reliable. Through the optimization of the formulation, we obtained uniform and stable DSNPs, which could escape from lysosomes of tumor cells. The optimized formulations were stable for intravenous administration. This study could provide scientific support for the development of nano-drug delivery system of small anti-tumor drug.

Reduction Responsive Self-Assembled Nanoparticles Based on Disulfide-Linked Drug-Drug Conjugate with High Drug Loading and Antitumor Efficacy.

Most anticancer drugs are poorly soluble and nonspecific, which restricts their clinical application. Drug conjugates, as a prodrug strategy, provide the possibility to overcome these shortcomings, especially combined with nanotechnology. Drug conjugate nanoparticles possess the advantages of high drug loading capacity and passive tumor targeting ability. Here, we prepared doxorubicin drug-drug conjugate nanoparticles (DOX-SS-DOX NPs) based on disulfide-linked doxorubicin drug-drug conjugate (DOX-SS-DOX). Dynamic light scattering (DLS) and transmission electron microscope (TEM) characterization indicated that DOX-SS-DOX NPs were spherical with a uniform size distribution around 89 nm. DLS and in vitro release experiment revealed that DOX-SS-DOX NPs possessed reduction responsive activity. In vitro cellular uptake studies reflected that DOX-SS-DOX NPs could increase the uptake level substantially compared with DOX liposomes. Endocytosis mechanism assay demonstrated that DOX-SS-DOX NPs internalized into cells through a clathrin-mediated endocytosis pathway in an energy-dependent manner. In this manner, the amidase in lysosomes could break the amide bond to release free DOX, which would be helpful to antitumor activity. The in vitro cytotoxicity of DOX-SS-DOX NPs was a bit weaker than that of DOX liposomes, which might be the result of the slow cleavage of the disulfide bridge; but the antitumor efficacy of DOX-SS-DOX NPs evaluated in MCF-7 bearing mice was demonstrated to be higher than that of DOX liposomes. This might be because of the long lasting effect resulting from the slow cleavage of the disulfide bond. In summary, DOX-SS-DOX NPs, prepared nearly totally with drug, provide a good strategy for cancer therapy.

Peptide-functionalized, -assembled and -loaded nanoparticles in cancer therapy.

The combination of peptides and nanoparticles in cancer therapy has shown synergistic results. Nanoparticle functionalization with peptides can increase their targeting ability towards tumor cells. In some cases, the peptides can develop self-assembled nanoparticles, in combination with drugs, for targeted cancer therapy. The peptides can be loaded into nanoparticles and can be delivered by other drugs for synergistic cancer removal. Multifunctional types of peptide-based nanoparticles, including pH- and redox-sensitive classes, have been introduced in cancer therapy. The tumor microenvironment remolds, and the acceleration of immunotherapy and vaccines can be provided by peptide nanoparticles. Moreover, the bioimaging and labeling of cancers can be mediated by peptide nanoparticles. Therefore, peptides can functionalize nanoparticles in targeted cancer therapy.

Hollow carbon spheres derived from self-assembled chitosan/poly(γ-glutamic acid) nanoparticles for oil-in-water emulsion separation.

With the rapid science and technology advancement, the oil-water separation in oily wastewater has become an urgent problem, especially the emulsified oil-water mixtures. Hollow carbon spheres (HCSs) have tremendous potential in separating oil-water emulsions due to their rich porous channels and high surface-to-volume ratio. In this work, as-prepared chitosan/poly(γ-glutamic acid) nanoparticles crosslinked by Ni2+ (Ni2+/CS/γ-PGA NPs) were used as carbon precursor to fabricate HCSs. This strategy separated the formation process of the biomolecular microspheres and the carbonization process. Especially, the Ni2+/CS/γ-PGA NPs were fabricated from the self-assembly of chitosan and γ-PGA in aqueous solution and the crosslinking of Ni2+ via the electrostatic interactions, facilitating the formation of biomolecular microspheres and making the usable of biomolecule-based carbon precursors diversity. After lyophilization, Ni2+/CS/γ-PGA NPs powder was obtained, which was then carbonized in a tube furnace under N2 atmosphere. During the carbonization process, the nickel species aggregated together to form the core of nickel@carbon nanoparticles, and carbon formed the shell. At last, nickel nanoparticles were removed from the carbon framework by hydrochloric acid, obtaining HCSs with super-hydrophobicity and lipophilicity. The as-prepared HCSs exhibited excellent separation performance in oil-in-water emulsions.