Nanocarriers for Active Ingredients of Chinese Medicine (AIFCM) Used in Gastrointestinal Cancer Therapy

Active ingredients of Chinese medicine (AIFCM) are pharmacological substances taken from traditional Chinese medicine that show promise in treating gastrointestinal cancer. Compared with traditional chemotherapeutic drugs, AIFCM have advantages such as multi-target and multi-level treatment of gastrointestinal cancer. Nanocarriers have the following advantages, better bioavailability, passive or active targeting of tumor sites and responsive release of drugs. The use of nanocarriers for delivery of AIFCM in treatment of gastrointestinal cancer, can overcome the disadvantages of some AIFCM, such as insolubility and low bioavailability. In this review, we first outline the background on gastrointestinal cancer, main curative factors and conventional therapeutic approaches. Then, the mechanisms for AIFCM in gastrointestinal cancer therapy are presented in the following four aspects: gene regulation, immune modulation, cellular pathway transduction, and alteration of intestinal flora. Thirdly, preparation of various nanocarriers and results when combining AIFCM in gastrointestinal cancer are presented. Fourth, application of novel targeted nanocarriers and responsive nanocarriers in gastrointestinal tumors is further introduced. Finally, the application of AIFCM in the treatment of gastrointestinal cancer is summarized and prospected, hoping to shed some light on the nanocarrier-bound AIFCM in the treatment of gastrointestinal cancer.

Near-Infrared Liposome-Capped Au-Rare Earth Bimetallic Nanoclusters for Fluorescence Imaging of Tumor Cells

Early detection of cancer can effectively improve the survival rate of cancer patients. Fluorescence imaging has the advantages of high sensitivity and rapid imaging, and is widely used in the precise imaging detection of tumors. In this study, five kinds of Au-rare earth bimetallic nanoclusters (Au/Ln NCs) were prepared by template method using five representative rare earth elements doped with gold. The morphologies, surface charges, sizes, fluorescence quantum yields and maximum fluorescence emission wavelengths of these five kinds of Au/Ln NCs were characterized and contrasted. The findings indicated that the Au/Ce nanoclusters (Au/Ce NCs) prepared by Ce doping have the longest fluorescence emission wavelength (695 nm) and higher quantum yield, which could effectively avoid the interference of autofluorescence, and was suitable for fluorescence imaging of tumor cells. In order to improve the specific accumulation of nanoclusters in tumor cells, Au/Ce NCs were coated with folic acid modified liposomes (lip-FA) to constructed a targeted fluorescent imaging probe with near-infrared response (Au/Ce@lip-FA), which was successfully used for fluorescence imaging of tumor cells. The probe has the characteristics of stable fluorescence signal, good targeting, easy internalization, and safe metabolism, and can provide high-resolution and high-brightness imaging information, which is expected to play an important role in the clinical diagnosis and surgical treatment of tumors.

Liposome Nanoparticles Carrying miR-22 Suppress Proliferation, Invasion and Epithelial–Mesenchymal Transition (EMT) of Laryngeal Squamous Cell Carcinoma by Targeting Wingless-Related Integration Site (WNT) Pathway

Abnormal miR-22 level is related to laryngeal squamous cell carcinoma (LSCC) progression. This study mainly assessed its role in proliferation, invasion and EMT of LSCC and their possible mechanisms of action. HN4 was collected, and corresponding groups were set as; blank group, positive control group, miR-22 group and MIRNA-22 NC group. Pathway inhibitor group and pathway agonist group were also set. The expressions of miR-22, EMT-related genes, cell proliferation rate, invasion rate, β-catenin and Cyclin D1 were observed. Results revealed that, expressions of miR-22 and e-cadherin were higher in the blank group and miR-22 NC group, while N-cadherin and Vimentin levels were lower. Moreover, miR-22 and EMT-related genes in the positive control group and miR-22 group were opposite (P <0.05). The proliferation rate and invasion rate of blank and miR-22 NC groups were also lower, while positive control and miR-22 groups showed different changes (P <0.05). β-catenin and Cyclin D1 expressions in the blank group and miR-22 NC group were increased compared to other two groups. The proliferation rate, invasion rate, expression of N-cadherin and Vimentin were higher and E-cadherin was lower in blank and pathway agonist group, which was opposite in the pathway inhibitor group (P < 0.05). β-catenin and Cyclin D1 protein levels in blank and pathway agonist groups were higher than pathway inhibitor group (P < 0.05). A binding region between miR-22 gene sequence and 3′UTR 215-229 sequence of Wnt gene was found and Wnt was found to be the target gene for miR-22. The fluorescence intensity of mutant plasmid was higher than wild-type plasmid (P <0.05). miR-22 can inhibit LSCC proliferation, invasion and EMT and the main mechanism of action is related to the Wnt signaling pathway. MiR-22 targeted Wnt gene and inhibited Wnt signaling pathway activity, lower key factor beta catenin expression Wnt pathways, thereby inhibiting factor laryngeal squamous cancer cells proliferation, Cyclin D1 expression, resulting in inhibition of cell proliferation, and EMT process at the same time, reducing the cell invasion ability, inhibiting the growth of laryngeal squamous cancer cells. Eventually, the Wnt pathways or miR-22 all can be used as targets for laryngeal squamous carcinoma.

Effect of Propofol Nanoemulsion on Brain Perilymph Metabolism Through Transforming Growth Factor β1/Extracellular Signal Regulated Kinase 5 (TGF-β1/ERK5) Signaling Pathway

Propofol takes part in the metabolism of perilymph in the brain. Propofol nanoemulsion can enhance the efficacy of drugs. This study explored how propofol modified by nanoemulsion inhibited the TGF-β1/ERK5 signaling pathway, thus affecting the brain. The role of perilymph metabolism, and its mechanism of action were also clarified. 40 SD rats of clean grade were separated into 4 groups, namely; control group, propofol, propofol nanoemulsion and TGF-β1/ERK5 inhibitor group. We observed the particle size and potential of propofol nanoemulsion, concentration of several groups of immune factors, inflammatory factors, TGF-β1, and ERK5 protein expression. Results from the laser particle size analyzer showed that the average particle size for the propofol nanoemulsion was 87.14 nm. The zeta potential was 0.391 mV, which was close to electrical neutrality. ELISA results showed that the concentrations of IgG, IgA, and lgM in the propofol group, propofol nanoemulsion group, and TGF-β1/ERK5 inhibitor group were evidently lower and the IgG, IgA, IgM concentration for the propofol nanoemulsion group. Moreover, the concentration was lower than that of other groups. ELISA test results showed that the concentrations of IL-12, IL-10, TNF-α, and IL-2 in the propofol group, propofol nanoemulsion group, and TGF-β1/ERK5 inhibitor group were obviously lower. The concentrations of IL-12, IL-10, TNF-α and IL-2 in the propofol nanoemulsion group were lower than those in the other groups (p < 0.05). These results exhibited that, the expression levels of TGF-β1 and ERK5 in the propofol group, propofol nanoemulsion group, and TGF-β1/ERK5 inhibitor group were evidently lower. TGF-β1 and ERK5 expression levels in the propofol nanoemulsion group was lower than in the other groups (p<0.05). Propofol nanoemulsion regulates the TGF-β1/ERK5 signaling pathway, inhibits its expression, reducing inflammation, increasing immune response, and promoting perilymph metabolism in the brain.

Nano-Albumin Particles Loaded with miR-20a Inhibitor Targeting Met Protein to Reverse Proliferation of Intestinal Cancer Cells

This study explored miR-20a’s role in intestinal cancer cells. SW480 cell line was divided into control group, agonist group, inhibitor group, and negative control group, followed by analysis of cell proliferation, apoptosis, Met, Bad, and Bcl-2 protein expressions. Results showed that miR-20a expression in the agonist group was the highest, followed by blank group and negative control group, and inhibitor group was lowest. S-phase and G2/M cell number from inhibitor group was lowest, and cell apoptosis rate was highest. However, the agonist group showed contrary changes. There was no difference in G0/G1 phase cell number among the four groups (P > 0.05). Moreover, the expressions of Bad, Bcl-2, Met, Wnt, β-catenin, and p-Wnt in inhibitor group were all lower, while the expressions in agonist group were all high (P < 0.05). S-phase and G2/M cell number in inhibitor group was lowest, while cell apoptosis was highest. The agonist group was opposite, with G0/G1 phase cells in each group showing no difference (P > 0.05). Wnt, β-catenin, and p-Wnt expressions were lowest in the inhibitor group, while the agonist group was opposite. These results together showed that the miR-20a directly targeted and regulated Met protein. Finally, the miR-20a inhibited intestinal cancer cell proliferation mainly through inhibiting Wnt/β-catenin signaling activity.

Protective Effect of Iron Oxide Nanoparticles on Periodontal Injury in Rats by Inhibiting Collagenase-1 and Alkaline Phosphatase Expression

This study intends to assess whether iron oxide nanoparticles affect periodontal injury and collagenase-1 (COL-1), and alkaline phosphatase (ALP) in rats. In this study, the ALP activity and Col-1 concentration in rats with periodontal injury were determined.We detected the periodontal histopathological changes and expression of periodontal pocket depth (PD) and attachment loss (AL) by Hematoxylin and eosin (HE) staining.We also detected Col-1 and ALP proteins in periodontal tissues by Western blot. Real-time reverse transcription-polymerase chain reaction (RT-PCR) detected Col-1 and ALP mRNA level in periodontal tissues of rats in each group, while ALP activity and Col-1 concentration in gingival crevicular fluid in model group increased compared to sham group (P < 0.05). After intervention by iron oxide nanoparticles, ALP activity and Col-1 concentration in the gingival crevicular fluid of model rats decreased greatly (P < 0.05). The gingival atrophy was more serious in model group, and many inflammatory cells infiltrated into the tissue and destroyed the alveolar tissue. Meanwhile, the periodontal tissue from rats in intervention group was greatly improved, and the degree of alveolar bone destruction was also significantly reduced, while the PD and AL periodontal indexes were significantly inhibited (P < 0.05). The protein and relative expression showed that the protein and mRNA expressions of ALP and Col-1 in periodontal tissue from model group were lower than those in sham group (P < 0.05). After intervention by iron oxide nanoparticles, the protein and mRNA expressions of ALP and Col-1 in the periodontal tissues in intervention group increased (P < 0.05). Iron oxide nanoparticles can thus inhibit the expression of ALP and COL-1 in periodontal injury rats, and improve the periodontal injury tissue.

Effect of Polysaccharide Sulfate-Loaded Poly(lactic-co-glycolic acid) Nanoparticles on Coronary Microvascular Dysfunction of Diabetic Cardiomyopathy

Diabetic cardiomyopathy (DCM) mainly results from development of coronary microcirculatory dysfunction (CMD). Polysaccharide sulfate (PSS), as one heparin drug, has a variety of biological activities. This study examined the efficacy of a new type of PSS-loaded poly lactic-co-glycolic acid (PLGA) nanoparticles (PSS-NPs) on DCM, in finding a theoretical basis for CMD treatment. After establishment of DCM model, the animals were administrated with PSS, PSS-NPs, normal saline or poly(ethylene glycol)1 (PEG1) through intraperitoneal injection. 8 weeks after injection of streptozotocin (STZ), heart function of rats was assessed by echocardiography. The rat tissues were collected and detected by histological analysis. Quantitative reverse transcription PCR (RT-qPCR) and Western blot analyses determined the levels of malondialdehyde (MDA), glutathione (GSH), superoxide dismutase (SOD), and pro-inflammatory factors. PSS-NPs had a good protective effect on cardiac insufficiency in rats. Administration of PSS-NPs prolonged survival state, and enhanced cardiac function, thereby alleviating the symptoms, and inducing formation of micro vessels. Importantly, it improved the symptoms of DCM patients and their quality of life. Moreover, pro-inflammatory factor levels decreased upon the treatment, accompanied with inactivation of NF-κB signaling pathways, thereby improving DCM. This study demonstrated that the PSS-NPs significantly relieved DCM and restored cardiac function in rats through NF-κB signaling pathways, providing a theoretical basis for development of PSS-NPs, and new treatment ideas for CMD of DCM.

A Novel Targeted Delivery of Valeric Acid Using Liposomal Nanoparticles in Treatment of Lung Cell Carcinoma

With a high mortality rate, non-small cell lung cancer (NSCLC) is a major challenge for patients and clinicians. The high cost and side effects of chemo-drugs severely influence disease outcome. With advantages of action prolongation and solitary target for embedded drugs, liposomal nanoparticle-based modification was investigated in this study with valeric acid, aimed at exploring its impacts and value on NSCLC. The efficacy comparisons of chemo-drugs (cisplatin, paclitaxel and liposomal nanoparticle-modified valeric acid) were conducted utilizing human NSCLC cell lines, normal lung fibroblasts, pulmonary epithelial cell line, and mouse tumor models. Additionally, the underlying therapeutic mechanisms for this novel liposomal nanoparticle in NSCLC were also explored via analysis of protein changes in tumor tissues. Results showed that, in comparison with conventional chemotherapeutics (cisplatin and paclitaxel), novel liposomal nanoparticle-modified valeric acid effectively retarded the growth of human NSCLC cell lines to a greater extent, and even successfully restrained further progression of tumor tissues in vivo. Furthermore, this novel liposomal nanoparticle-modified valeric acid exhibited lower cytotoxicity towards normal lung cell lines. Additionally, the anti-cancer function of this novel liposomal nanoparticle-modified valeric acid was found to be related to STAT3/Cyclin D1 pathway. The current study confirmed that, compared with cisplatin and paclitaxel, this novel liposomal nanoparticle-modified valeric acid displayed significant therapeutic effect on NSCLC, with lower cytotoxicity to normal cells. It has therefore further promoted research progress and significance on NSCLC research in the clinical management of NSCLC.

Injectable Functional Biomaterials for Minimally Invasive Surgery

Injectable materials represent very attractive ready-to-use biomaterials for application in minimally invasive surgical procedures. It is shown that this approach to treat, for example, vertebral fracture, craniofacial defects, or tumor resection has significant clinical potential in the biomedical field. In the last four decades, calcium phosphate cements have been widely used as injectable materials for orthopedic surgery due to their excellent properties in terms of biocompatibility and osteoconductivity. However, few clinical studies have demonstrated certain weaknesses of these cements, which include high viscosity, long degradation time, and difficulties being manipulated. To overcome these limitations, the use of sol-gel technology has been investigated, which has shown good results for synthesis of injectable calcium phosphate-based materials. In the last few decades, injectable hydrogels have gained increasing attention owing to their structural similarities with the extracellular matrix, easy process conditions, and potential applications in minimally invasive surgery. However, the need to protect cells during injection leads to the development of double network injectable hydrogels that are capable of being cross-linked in situ. This review will provide the current state of the art and recent advances in the field of injectable biomaterials for minimally invasive surgery.

Delivery of drugs, proteins, and nucleic acids using inorganic nanoparticles

Inorganic nanoparticles provide multipurpose platforms for a broad range of delivery applications. Intrinsic nanoscopic properties provide access to unique magnetic and optical properties. Equally importantly, the structural and functional diversity of gold, silica, iron oxide, and lanthanide-based nanocarriers provide unrivalled control of nanostructural properties for effective transport of therapeutic cargos, overcoming biobarriers on the cellular and organismal level. Taken together, inorganic nanoparticles provide a key addition to the arsenal of delivery vectors for fighting disease and improving human health.

A pH-sensitive carrier based-on modified hollow mesoporous carbon nanospheres with calcium-latched gate for drug delivery

A novel nanocarrier based-on hollow mesoporous carbon nanospheres (HMCNs) with primary amines on its surface, a large cavity, and good hydrophilicity was synthesized by a hydrothermal reaction. The primary amine functionalities on the mesoporous carbon were used as the initiation sites for growing poly (epichlorohydrin) (PCH) chains. The chlorine groups in the side chain of PCH were replaced with imidazole as the pendant groups. Calcium chloride (CaCl₂) was applied as a capping agent. The coordination bonding was formed between pendant imidazole groups and calcium ions. Doxorubicin (DOX) was selected as a model of hydrophilic anticancer drug and was loaded onto the nanocarrier and released through the cleavage of the pH-sensitive coordination bonding. The gating mechanism enables the nanocarrier to store and release the calcium ions and the DOX molecules trapped in the pores. MTT assay toward HeLa cells indicated that the nanocarrier had low toxicity because of the surface modification with the oxygen-rich polymer. The cellular uptake of the pH-sensitive nanocarrier for HeLa cancer cell lines was confirmed by CLSM images and flow cytometry. So, the novel pH-sensitive nanocarrier can be applicable to carry and release both DOX drug and calcium ions for cancer treatment.

Protoporphyrin IX-loaded laminarin nanoparticles for anticancer treatment, their cellular behavior, ROS detection, and animal studies

Laminarin conjugate-based nano-scaled particles were in this study proposed as a delivery system for protoporphyrin IX (Pp IX) in photodynamic therapy (PDT) of human breast cancer cells (MCF-7). Hematin-Laminarin-Dithiodipropionic Acid-MGK, named as HLDM, was an amphiphilic carrier material with dual pH/redox sensitive that could be used to load hydrophobic drug to improve their solubility and enhance biocompatibility. Therefore, we combined photosensitizer (Pp IX) with HLDM to fabricate a novel nano-micelles, herein called Pp IX-loaded HLDM micelles. The Pp IX-loaded HLDM micelles were 149.3 ± 35 nm sized in neutral water. Phototoxicity, in vitro PDT effect, and dual sensibility to pH and redox microenvironment of Pp IX-loaded HLDM micelles were examined at different concentrations by using MCF-7 human breast cancer cells. The experiments on phototoxicity and reactive oxygen species (ROS) production proved that the micelles could produce PDT to kill the cancer cells with a certain wavelength light. The apoptosis experiment indicated that the micelles could cause nuclear damage. In vivo PDT effect of the micelles was studied by constructing the tumor-bearing nude mouse model of MCF-7 cells. In vivo studies showed that the Pp IX-loaded HLDM micelles could induce remarkable anti-tumor effect. A promising laminarin-based nanomedicine platform acts as a new drug delivery system to enhance the uptake, accumulation, and PDT efficacy of Pp IX in vitro and in vivo.

Poly(ethylene glycol) Grafting of Nanoparticles Prevents Uptake by Cells and Transport Through Cell Barrier Layers Regardless of Shear Flow and Particle Size

It has long been a central tenet of biomedical research that coating of nanoparticles with hydrated polymers can improve their performance in biomedical applications. However, the efficacy of the approach in vivo is still debated. In vitro model systems to test the performance of engineered nanoparticles for in vivo applications often use nonrepresentative cell lines and conditions for uptake and toxicity tests. We use our platform of monodisperse iron oxide nanoparticles densely grafted with nitrodopamide-poly(ethylene glycol) (PEG) to probe cell interactions with a set of cell types and culture conditions that are relevant for applications in which nanoparticles are injected into the bloodstream. In the past, these particles have proved to have excellent stability and negligible interaction with proteins and membranes under physiological conditions. We test the influence of flow on the uptake of nanoparticles. We also investigate the transport through endothelial barrier cell layers, as well as the effect that PEG-grafted iron oxide nanoparticles have on cell layers relevant for nanoparticles injected into the bloodstream. Our results show that the dense PEG brush and resulting lack of nonspecific protein and membrane interaction lead to negligible cell uptake, toxicity, and transport across barrier layers. These results contrast with far less well-defined polymer-coated nanoparticles that tend to aggregate and consequently strongly interact with cells, for example, by endocytosis.

PEGylated Protamine-Based Adsorbing Improves the Biological Properties and Stability of Tetrahedral Framework Nucleic Acids

Recently, many researchers have reported that DNA nanostructures, such as tetrahedral framework nucleic acids (tFNAs), have great potential to be useful tools in clinical and laboratory applications due to their programmable shapes, functional sites, and biological responses. However, finite endocytosis and stability in cells and body fluids compromise the functions of DNA nanostructures as a result of various adverse factors. In this study, we successfully synthesized PEGylated protamine, and tFNAs were adsorbed to it in a proper ratio of nitrogen in protamine to phosphorus in tFNAs (N/P ratio) as the functional complex. Furthermore, we demonstrated that PEGylated protamine-adsorbed tFNAs show a more prominent positive effect on cell viability and proliferation than naked tFNAs do. An increase in endocytosis can be observed in three different tissue-derived cells with the PEG-protamine-tFNA (PPT) complex. The increased endocytic ability is mediated by multiple pathways; moreover, the stimulatory effect of the PPT complex on the endocytic ability is dramatically blocked by the inhibition of the caveola-dependent pathway. Consistently, when tFNAs are stabilized by PEGylated protamine, they often tend to escape from lysosomes and survive for a longer period in biological fluids rather than being rapidly eliminated from the kidneys. The in vitro and in vivo results of our study demonstrate that the PPT complex method is a feasible, potent, and low-cost strategy that improves tFNA biocompatibility, stability, and internalization. This study provides evidence supporting the possibility of implementing PPTs for use in drug delivery, bioimaging, and gene transfection in the future.

Characteristics and mechanism associated with drug conjugated inorganic nanoparticles

Nanoparticles have several exciting applications nowadays almost in every area. Biomedical field is one of them where nanoparticles show potential for various applications due to their exceptional and exciting properties. The presence of heavy metals in inorganic nanoparticles lead to toxicity in the biological system, therefore, their direct use for drug delivery is restricted. But encapsulating their surface with a non-toxic or biocompatible material makes them a promising material for application in drug delivery system. This review highlights the various characteristics and factors involved in nano-drug delivery system. The understanding of various mechanisms involved during the uptake of nanoparticles by cells, toxicity, surface chemistry and several drug release mechanisms has been discussed. This article also includes various computational studies used to optimise the design and properties of drug delivery system.

Lanthanide-Doped Upconversion Nanocarriers for Drug and Gene Delivery

Compared to traditional cancer treatments, drug/gene delivery is an advanced, safe, and efficient method. Nanoparticles are widely used as nanocarriers in a drug/gene delivery system due to their long circulation time and low multi-drug resistance. In particular, lanthanide-doped upconversion nanoparticles (UCNPs) that can emit UV and visible light by near-infrared (NIR) upconversion demonstrated more efficient and safer drug/gene delivery. Because of the low penetration depth of UV and visible light, a photoinduced reaction such as photocleavage or photoisomerization has proven restrictive. However, NIR light has high tissue penetration depth and stimulates the photoinduced reaction through UV and visible emissions from lanthanide-doped UCNPs. This review discusses the optical properties of UCNPs that are useful in bioapplications and drug/gene delivery systems using the UCNPs as a photoreaction inducer.

Injectable hydrogels for cartilage and bone tissue engineering

Tissue engineering has become a promising strategy for repairing damaged cartilage and bone tissue. Among the scaffolds for tissue-engineering applications, injectable hydrogels have demonstrated great potential for use as three-dimensional cell culture scaffolds in cartilage and bone tissue engineering, owing to their high water content, similarity to the natural extracellular matrix (ECM), porous framework for cell transplantation and proliferation, minimal invasive properties, and ability to match irregular defects. In this review, we describe the selection of appropriate biomaterials and fabrication methods to prepare novel injectable hydrogels for cartilage and bone tissue engineering. In addition, the biology of cartilage and the bony ECM is also summarized. Finally, future perspectives for injectable hydrogels in cartilage and bone tissue engineering are discussed.

Long Blood Residence and Large Tumor Uptake of Ruthenium Sulfide Nanoclusters for Highly Efficient Cancer Photothermal Therapy

Transition metal sulfide (TMS) holds great potential in cancer photothermal therapy (PTT) because of the high absorbance in the near-infrared (NIR) region. The short blood circulation time and limited tumor accumulation of TMS-based photothermal agents, however, limit their applications. Herein, we design a novel TMS-based PTT agent, ruthenium sulfide-based nanoclusters (NCs), to overcome the current limitations. We firstly develop a simple method to prepare oleic acid coated ruthenium sulfide nanodots (OA-RuS1.7 NDs) and assemble them into water-soluble NCs via sequentially coating with denatured bovine serum albumin (dBSA) and poly(ethylene glycol) (PEG). The obtained PEG-dBSA-RuS1.7 NCs possess excellent photothermal conversion ability. More significantly, they exhibit enhanced blood circulation time and tumor-targeting efficiency in vivo compared with other TMS-based PTT nanoagents, which may be attributed to their appropriate hydrodynamic diameter (~70 nm) and an ideal charge (~0 mV). These characteristics help the PEG-dBSA-RuS1.7 NCs to escape the removal by the reticuloendothelial system (RES) and kidney. All these advantages enable the PEG-dBSA-RuS1.7 NCs to selectively concentrate in tumor sites and effectively ablate the cancer cells upon NIR irradiation.

Huge enhancement of upconversion luminescence by broadband dye sensitization of core/shell nanocrystals

The UCL intensity of dye-sensitized UCNCs excited at 820 nm is 800-folds higher than that of pure UCNCs excited at 980 nm.

Small GSH-Capped CuInS2 Quantum Dots: MPA-Assisted Aqueous Phase Transfer and Bioimaging Applications

An efficient ligand exchange strategy for aqueous phase transfer of hydrophobic CuInS2/ZnS quantum dots was developed by employing glutathione (GSH) and mercaptopropionic acid (MPA) as the ligands. The whole process takes less than 20 min and can be scaled up to gram amount. The material characterizations show that the final aqueous soluble samples are solely capped with GSH on the surface. Importantly, these GSH-capped CuInS2/ZnS quantum dots have small size (hydrodynamic diameter <10 nm), moderate fluorescent properties (up to 34%) as well as high stability in aqueous solutions (stable for more than three months in 4 °C without any significant fluorescence quenching). Moreover, this ligand exchange strategy is also versatile for the aqueous phase transfer of other hydrophobic quantum dots, for instance, CuInSe2 and CdSe/ZnS quantum dots. We further demonstrated that GSH-capped quantum dots could be suitable fluorescence markers to penetrate cell membrane and image the cells. In addition, the GSH-capped CuInS2 quantum dots also have potential use in other fields such as photocatalysis and quantum dots sensitized solar cells.

Independent effect of polymeric nanoparticle zeta potential/surface charge, on their cytotoxicity and affinity to cells

OBJECTIVES

Up to now, little research has been focussed on discovering how zeta potential independently affects polymeric nanoparticle (NP) cytotoxicity.

METHODS

Polymeric nanoparticles of gradient zeta potential ranging from -30 mv to +40 mv were fabricated using the same poly-3-hydroxybutyrate-co-3-hydroxyhexanoate (PHBHHx) biopolymer. Interaction forces between nanoparticles and cells were measured by atomic force microscopy (AFM). Cytotoxicity of the nanoparticles to cells was investigated by using MTT (3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide) assay.

RESULTS

Four kinds of nanoparticle with similar sizes and gradient zeta potentials, were fabricated. Those with positive surface charges were found to be more toxic than those with negative surface charges. Positively charged nanoparticles or nanoparticles with higher 'like' charges, offered higher interaction force with cells.

CONCLUSION

This work proposes a novel approach for investigating interaction between NPs and cells, and discloses the importance of controlling zeta potential in developing NPs-based formulations in the future.

Manganese doped iron oxide theranostic nanoparticles for combined T1 magnetic resonance imaging and photothermal therapy

Photothermal therapy (PTT) is a noninvasive and convenient way to ablate tumor tissues. Integrating PTT with imaging technique could precisely identify the location and the size of tumor regions, thereby significantly improving the therapeutic efficacy. Magnetic resonance imaging (MRI) is widely used in clinical diagnosis due to its superb spatial resolution and real-time monitoring feature. In our work, we developed a theranostic nanoplatform based on manganese doped iron oxide (MnIO) nanoparticles modified with denatured bovine serum albumin (MnIO-dBSA). The in vitro experiment revealed that the MnIO nanoparticles exhibited T1-weighted MRI capability (r1 = 8.24 mM(-1) s(-1), r2/r1 = 2.18) and good photothermal effect under near-infrared laser irradiation (808 nm). Using 4T1 tumor-bearing mice as an animal model, we further demonstrated that the MnIO-dBSA composites could significantly increase T1 MRI signal intensity at the tumor site (about two times) and effectively ablate tumor tissues with photoirradiation. Taken together, this work demonstrates the great potential of the MnIO nanoparticles as an ideal theranostic platform for efficient tumor MR imaging and photothermal therapy.

Towards hybrid biocompatible magnetic rHuman serum albumin-based nanoparticles: use of ultra-small (CeLn)3/4+ cation-doped maghemite nanoparticles as functional shell

Human serum albumin (HSA) is a protein found in human blood. Over the last decade, HSA has been evaluated as a promising drug carrier. However, not being magnetic, HSA cannot be used for biomedical applications such as magnetic resonance imaging (MRI) and magnetic drug targeting. Therefore, subsequent composites building on iron oxide nanoparticles that are already used clinically as MRI contrast agents are extensively studied. Recently and in this context, innovative fully hydrophilic ultra-small CAN-stabilized maghemite ((CeLn)(3/4+)-γ-Fe2O3) nanoparticles have been readily fabricated. The present study discusses the design, fabrication, and characterization of a dual phase hybrid core (rHSA)-shell ((CeLn)(3/4+)-γ-Fe2O3 NPs) nanosystem. Quite importantly and in contrast to widely used encapsulation strategies, rHSA NP surface-attached (CeLn)(3/4+)-γ-Fe2O3 NPs enabled to exploit both rHSA (protein functionalities) and (CeLn)(3/4+)-γ-Fe2O3 NP surface functionalities (COOH and ligand L coordinative exchange) in addition to very effective MRI contrast capability due to optimal accessibility of H2O molecules with the outer magnetic phase. Resulting hybrid nanoparticles might be used as a platform modular system for therapeutic (drug delivery system) and MR diagnostic purposes.