Folate-modified chitosan micelles with enhanced tumor targeting evaluated by near infrared imaging system

Research Progress of Chitosan-based Multifunctional Nanoparticles in Cancer Targeted Therapy

Conventional tumor therapeutic modalities, such as radiotherapy, chemotherapy, and surgery, involve low tumor inhibition efficiency, non-targeted drug delivery, and side effects. The development of novel and practical nano-drug delivery systems (DDSs) for targeted tumor therapy has become particularly important. Among various bioactive nanoparticles, chitosan is considered a suitable candidate for drug delivery due to its nontoxicity, good biocompatibility, and biodegradability. The amino and hydroxyl groups of chitosan endow it with the diverse function of chemical modification, thereby improving its physical and biological properties to meet the requirements of advanced biomedical applications. Therefore, it is necessary to review the property and applications of chitosan- based materials in biomedicine. In this review, the characteristics of chitosan related to its applications are first introduced, and then the preparation and modification of chitosan-based nanoparticles, including the function tailoring of chitosan-modified nanoparticles, are demonstrated and discussed. Finally, the opportunities and challenges of chitosan- based nanomaterials in this emerging field are proposed from the perspective of the rational and systematic design for the biomedicine field.

Assessment of Physicochemical and In Vivo Biological Properties of Polymeric Nanocapsules Based on Chitosan and Poly(N-vinyl pyrrolidone-alt-itaconic anhydride)

Drug delivery is an important field of nanomedicine, and its aim is to deliver specific active substances to a precise site of action in order to produce a desired pharmacological effect. In the present study nanocapsules were obtained by a process of interfacial condensation between chitosan (dissolved in the aqueous phase) and poly(N-vinyl pyrrolidone-alt-itaconic anhydride), a highly reactive copolymer capable of easily opening the anhydride ring under the action of amine groups of chitosan. The formed amide bonds led to the formation of a hydrogel membrane. The morphology of the obtained nanocapsules, their behavior in aqueous solution of physiological pH, and their ability to encapsulate and release a model drug can be modulated by the parameters of the synthesis process, such as the molar ratio between functional groups of polymers and the ratio of the phases in which the polymers are solubilized. Although a priori both polymers are biocompatible, this paper reports the results of a very detailed in vivo study conducted on experimental animals which have received the obtained nanocapsules by three administration routes—intraperitoneal, subcutaneous, and oral. The organs taken from the animals’ kidney, liver, spleen, and lung and analyzed histologically demonstrated the ability of nanocapsules to stimulate the monocytic macrophage system without producing inflammatory changes. Moreover, their in vivo behavior has been shown to depend not only on the route of administration but also on the interaction with the cells of the organs with which they come into contact. The results clearly argue the biocompatibility of nanocapsules and hence the possibility of their safe use in biomedical applications.

Chitosan Nanoparticles at the Biological Interface: Implications for Drug Delivery

The unique properties of chitosan make it a useful choice for various nanoparticulate drug delivery applications. Although chitosan is biocompatible and enables cellular uptake, its interactions at cellular and systemic levels need to be studied in more depth. This review focuses on the various physical and chemical properties of chitosan that affect its performance in biological systems. We aim to analyze recent research studying interactions of chitosan nanoparticles (NPs) upon their cellular uptake and their journey through the various compartments of the cell. The positive charge of chitosan enables it to efficiently attach to cells, increasing the probability of cellular uptake. Chitosan NPs are taken up by cells via different pathways and escape endosomal degradation due to the proton sponge effect. Furthermore, we have reviewed the interaction of chitosan NPs upon in vivo administration. Chitosan NPs are immediately surrounded by a serum protein corona in systemic circulation upon intravenous administration, and their biodistribution is mainly to the liver and spleen indicating RES uptake. However, the evasion of RES system as well as the targeting ability and bioavailability of chitosan NPs can be improved by utilizing specific routes of administration and covalent modifications of surface properties. Ongoing clinical trials of chitosan formulations for therapeutic applications are paving the way for the introduction of chitosan into the pharmaceutical market and for their toxicological evaluation. Chitosan provides specific biophysical properties for effective and tunable cellular uptake and systemic delivery for a wide range of applications.

Overcoming the protein corona in chitosan-based nanoparticles

Numerous properties of chitosan have led to its extensive use in the formulation of nanomaterials for drug delivery. However, the cationic surface of chitosan-based nanoparticles adsorbs proteins upon exposure to biological fluids, forming a phenomenon known as 'protein corona'. This causes several effects such as decreased bioavailability and limited in vivo clinical applications of chitosan nanoparticles. Understanding and overcoming the effects of protein adsorption on chitosan nanoparticles is key for drug delivery purposes. This review focuses on the strategies implemented to increase the stability of chitosan nanoparticles in the systemic circulation by averting the formation of protein corona and the limitations of PEGylation.

Micellar Drug Delivery Systems Based on Natural Biopolymers

The broad diversity of structures and the presence of numerous functional groups available for chemical modifications represent an enormous advantage for the development of safe, non-toxic, and cost-effective micellar drug delivery systems (DDS) based on natural biopolymers, such as polysaccharides, proteins, and peptides. Different drug-loading methods are used for the preparation of these micellar systems, but it appeared that dialysis is generally recommended, as it avoids the formation of large micellar aggregates. Moreover, the preparation method has an important influence on micellar size, morphology, and drug loading efficiency. The small size allows the passive accumulation of these micellar systems via the permeability and retention effect. Natural biopolymer-based micellar DDS are high-value biomaterials characterized by good compatibility, biodegradability, long blood circulation time, non-toxicity, non-immunogenicity, and high drug loading, and they are biodegraded to non-toxic products that are easily assimilated by the human body. Even if some recent studies reported better antitumoral effects for the micellar DDS based on polysaccharides than for commercial formulations, their clinical use is not yet generalized. This review is focused on the studies from the last decade concerning the preparation as well as the colloidal and biological characterization of micellar DDS based on natural biopolymers.

Potential applications of hydrophobically modified inulin as an active ingredient in functional foods and drugs - A review

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Inulin is a substance found in a wide variety of fruits, vegetables, and herbs.

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Inulin was modified by physical and chemical means to improve functionality.

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HMI has been used in the stability of emulsions and suspensions.

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SCFAs inulin esters have transformed the gut microbiota and improved the bioavailability of SCFAs.

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HMI based bioconjugates, hydrogel, and nanomicelles were used as a controlled release of drugs and vaccines.

Over the past few years, hydrophobically modified inulin (HMI) has gained considerable attention due to its multitudinous features. The targeted release of drugs remains a subject of research interest. Moreover, it is important to explore the properties of short-chain fatty acids (SCFAs) inulin esters because they are less studied. Additionally, HMI has been used to stabilize various dispersion formulations, which have been observed to be safe because inulin is generally recognized as safe (GRAS). However, the results regarding HMI-based dispersion products are dispersed throughout the literature. This comprehensive review is discussed the possible limitations regarding SCFAs inulin esters, real food dispersion formulations, and HMI drugs. The results revealed that SCFAs inulin esters can regulate the human gut microbiota and increase the biological half-life of SCFAs in the human body. This comprehensive review discusses the versatility of HMI as a promising excipient for the production of hydrophobic drugs.

Chitosan Nanoparticles-Insight into Properties, Functionalization and Applications in Drug Delivery and Theranostics

Nanotechnology-based development of drug delivery systems is an attractive area of research in formulation driven R&D laboratories that makes administration of new and complex drugs feasible. It plays a significant role in the design of novel dosage forms by attributing target specific drug delivery, controlled drug release, improved, patient friendly drug regimen and lower side effects. Polysaccharides, especially chitosan, occupy an important place and are widely used in nano drug delivery systems owing to their biocompatibility and biodegradability. This review focuses on chitosan nanoparticles and envisages to provide an insight into the chemistry, properties, drug release mechanisms, preparation techniques and the vast evolving landscape of diverse applications across disease categories leading to development of better therapeutics and superior clinical outcomes. It summarizes recent advancement in the development and utility of functionalized chitosan in anticancer therapeutics, cancer immunotherapy, theranostics and multistage delivery systems.

Biological Safety and Biodistribution of Chitosan Nanoparticles

The effect of unmodified chitosan nanoparticles with a size of ~100 nm and a weakly positive charge on blood coagulation, metabolic activity of cultured cardiomyocytes, general toxicity, biodistribution, and reactive changes in rat organs in response to their single intravenous administration at doses of 1, 2, and 4 mg/kg was studied. Chitosan nanoparticles (CNPs) have a small cytotoxic effect and have a weak antiplatelet and anticoagulant effect. Intravenous administration of CNPs does not cause significant hemodynamic changes, and 30 min after the CNPs administration, they mainly accumulate in the liver and lungs, without causing hemolysis and leukocytosis. The toxicity of chitosan nanoparticles was manifested in a dose-dependent short-term delay in weight gain with subsequent recovery, while in the 2-week observation period no signs of pain and distress were observed in rats. Granulomas found in the lungs and liver indicate slow biodegradation of chitosan nanoparticles. In general, the obtained results indicate a good tolerance of intravenous administration of an unmodified chitosan suspension in the studied dose range.

Near infra-red polymeric nanoparticle based optical imaging in Cancer diagnosis

Cancer disease is a foremost health concern and top basis of death in comparison with many diseases including cardiovascular disorders. During initial diagnosis (usually late diagnosis), a majority of cancer patients suffer from metastatic and advanced cancer stages which resulted in limited therapeutic modalities based interventions and effectiveness. Though considerable advancement has been made in combating the disease, continuous and intense efforts are ongoing for early diagnosis and development of therapies. Generally applied treatment options for cancer are surgery, chemotherapy and radiotherapy, which are restricted by failure to early diagnose, insufficient on-targeted drug delivery, systemic toxicity, and lack of real-time monitoring of therapeutic responses in cancer. Noninvasive imaging or minimally invasive imaging methodology is valuable in clinical diagnostic settings. Specifically, noninvasive optical imaging integrated with polymeric nanomaterial have been extensively investigated in the field of cancer diagnostics and therapy. Currently, optical imaging methods go together with polymer-based fluorescent nanoparticles in accomplishing the molecular level detection of tumor boundaries. NIR probe tagged polymeric nanoparticles have potential to provide an advantage in the early cancer detection, therapeutic monitoring and image guided surgery procedures. This article review the recent progress in state-of-the-art NIRF polymeric nanoparticles used for optical imaging particularly on cancer diagnosis.

Near-infrared imaging of diseases: A nanocarrier approach

Developments in fluorescence imaging, brought popularity to near infrared (NIR) imaging with far-red and NIR fluorophores applied for biosensing and bioimaging in living systems. Noninvasive NIR imaging gained popularity with the use of effective NIR dyes to obtain macroscopic fluorescence images. Several attributes of NIR dyes make them desirable agents, including high specificity, high sensitivity, minimized background interference, and the ability to easily conjugate with drug delivery systems. However, NIR dyes have some drawbacks and limitations, such as low solubility, low stability, and degradation. To overcome these issues, NIR dyes can be encapsulated in appropriate nanocarriers to achieve effective diagnosis, imaging, and therapy monitoring during surgery. Moreover, the vast majority of NIR dyes have photosensitizer features that can effectuate cancer treatment referred to as photodynamic therapy (PDT). In the near future, by combining NIR dyes with appropriate nanocarriers such as liposomes, polymeric micelles, polymeric nanoparticles, dendrimers, quantum dots, carbon nanotubes, or ceramic/silica based nanoparticles, the limitations of NIR dyes can be minimized or even effectively eliminated to form potential effective agents for imaging, therapy, and therapy monitoring of several diseases, particularly cancer.

Synthesis and characterization of chitosan-grafted-polycaprolactone micelles for modulate intestinal paclitaxel delivery

In this work, self-assembled amphiphilic micelles based on chitosan (CS) and polycaprolactone (PCL) were produced and used as carriers of paclitaxel (PTX) to improve its intestinal pharmacokinetic profile. Chitosan-grafted-polycaprolactone (CS-g-PCL) was synthesized through a carbodiimide reaction by amidation and confirmed by Fourier transform infrared spectroscopy (FTIR), hydrogen nuclear magnetic resonance analysis (¹H NMR), and contact angle evaluation. Micelles were produced by solvent evaporation method, and the critical micelle concentration was investigated by conductimetry. The obtained micelles were of 408-nm mean particle size, narrow size distribution (polydispersity index of 0.335) and presented positive surface charge around 30 mV. The morphology of micelles assessed by transmission electron microscopy (TEM) revealed round and smooth surface, in agreement with dynamic light scattering measurements. The association efficiency determined by high-performance liquid chromatography (HPLC) was as high as 82%. The in vitro cytotoxicity of the unloaded and PTX-loaded micelles was tested against Caco-2 and HT29-MTX intestinal epithelial cells, resulting in the absence of cell toxicity for all formulations. Moreover, the permeability of PTX-loaded micelles in Caco-2 monolayer and Caco-2/HT29-MTX co-culture model was determined. Results showed that the permeability of PTX was higher in Caco-2/HT29-MTX co-culture model compared with Caco-2 monolayer due to the mucoadhesive character of micelles, acting as a platform to deliver PTX at the sites of absorption. Therefore, it can be concluded that the PTX-loaded CS-g-PCL micelles, employed for the first time as PTX carriers, may be a potential drug carrier for the intestinal delivery of hydrophobic drugs, particularly anticancer agents.

A core/shell stabilized polysaccharide-based nanoparticle with intracellular environment-sensitive drug delivery for breast cancer therapy

In this work, we developed a novel core/shell chitosan (Cs)/hyaluronan (HA)-based hybrid nanoparticle, i.e. SNX@Cs-SNX/cHA, with good stability in the bloodstream and intracellular environment-sensitive drug delivery for breast cancer therapy.

Facile fabrication of poly(acrylic acid) coated chitosan nanoparticles with improved stability in biological environments

Chitosan is one of the most important and commonly used natural polysaccharides in drug delivery for its biocompatible and biodegradable properties. However, poor blood circulation of the chitosan nanoparticles due to their cationic nature is one of the major bottlenecks of chitosan-based drug delivery systems. To address this problem, a versatile platform based on poly(acrylic acid) (PAA) coated ionically cross-linked chitosan/tripolyphosphate nanoparticles (CTS/TPP-PAA NPs), is reported. The zeta potentials of CTS/TPP and CTS/TPP-PAA NPs are approximately 33mV and -25mV, respectively. CTS/TPP NPs quickly aggregate in PBS (phosphate buffered saline) and DMEM (Dulbecco's modified Eagle's medium). Conversely, CTS/TPP-PAA NPs exhibit excellent colloidal stability in plasma solution for more than 24h. The PAA coating also endows CTS/TPP-PAA NPs with decreased protein adsorption capacity and improved buffering capacity. More importantly, the residual carboxyl and amino groups on CTS/TPP-PAA NPs provide abundant reactive sites for further functional modifications. Therefore, the CTS/TPP-PAA NPs reported here may be useful as an alternative drug delivery system.

Pegylated Drug Delivery Systems: From Design to Biomedical Applications

Pegylation, as a simple procedure to attach hydrophilic polyethylene glycol (PEG) onto therapeutic molecule or drug carriers has been utilized widely to deliver small molecules, proteins and peptides. It was first reported in 1970s by Dr. Frank Davis of Rutgers University and Dr. Abuchowsky in the studies of PEG modified albumin and catalase. The significance of this method at that time was able to successfully modify the enzyme with better hydrophilicity but also keep the enzymatic activity. The employment of PEG has provided superior stability of drug delivery systems (DDS) and enhanced the circulation time in vivo. Simple conjugation of PEG chains with various molecular weights enables the possibility to regulate the properties of desired DDS and led to important contribution in targeting therapy and diagnosis. Pegylation has been reported to be able to protect peptides by shielding antigenic epitopes from reticuloendothelial (RES) clearance and avoid enzymes being recognized by immune system and avoid early degradation. In addition, utilization of PEG in DDS are reported with enhanced delivery efficiency, prolonged circulation time and improved stability, especially active enzymes and peptides drug delivery. In this paper, we will conclude current studies about Pegylated DDS and their biomedical applications from both in vitro and in vivo studies.

Peptide-Based Ligand for Active Delivery of Liposomal Doxorubicin

Doxorubicin (DOX) has been extensively used in the clinic to treat malignant tumors such as leukemias and Hodgkin’s lymphoma. However, the severe cardiotoxicity associated with the use of DOX requests the development of alternative and efficient pharmaceutical formulations. The PEGylated liposome of DOX can significantly reduce the cardiotoxicity but still lacks the active targeting towards cancer cells. Modification of liposomal DOX with active ligands would then be a rational approach to enhance the transportation of the toxin into tumor cells. Currently used targeting ligands include antibodies, proteins, small molecules, and peptides. By virtue of the advantages such as easy preparation, lower cost, and elevated resistance to enzymatic degradation, peptides are attracting a significant amount of interest as active targeting ligands for pharmaceutics. In this paper, we will briefly discuss the application of peptide ligands for the improvement of the therapeutic efficacy of liposomal DOX.

Quantitative SERS Detection of Trace Glutathione with Internal Reference Embedded Au-core/Ag-shell Nanoparticles

Surface-enhanced Raman scattering (SERS) has been widely studied and applied for over three decades. However, reliable SERS detection of molecules with low polarizability is still suffering from poor sensitivity and reproducibility. In this paper, we have reported a new strategy for performing quantitative SERS detection of Raman insensitive Glutathione (GSH), based on GSH-induced replacement of a highly Raman sensitive four-mercaptopyridine (MP) adsorbed on the surface of four-aminothiophenol (ATP) embedded Au-core/Ag-shell particles. This replacement led to a strong decrease of the MP SERS signal, which was used to determine the concentration of GSH. The adoption of GSH-induced Raman probe replacement leads to high sensitivity, while the use of internal reference method provides an improved accuracy of the GSH quantification.

A systematic in vitro investigation on poly-arginine modified nanostructured lipid carrier: Pharmaceutical characteristics, cellular uptake, mechanisms and cytotoxicity

The aim of the present study was to develop a poly-arginine modified nanostructured lipid carrier (R-NLC) by fusion-emulsification method and to test its pharmaceutical characteristics. The influence of R-NLC on A549 cells like cellular uptake and cytotoxicity was also appraised using unmodified NLC as the controlled group. As the results revealed, R-NLC had an average diameter of about 40 nm and a positive zeta potential of about +17 mv, the entrapment efficiency decreased apparently, and no significant difference on the in vitro drug release was found after R8-modification. The cellular uptake and cytotoxicity increased obviously compared with unmodified NLC. The cellular uptake mechanisms of R-NLC involved energy, macropinocytosis, clathrin-mediated endocytosis, and caveolin-mediated endocytosis. The outcomes of the present study strongly support the theory that cell penetrating peptides have the ability of enhancing the cellular uptake of nanocarriers.

Characteristics and cytotoxicity of folate-modified curcumin-loaded PLA-PEG micellar nano systems with various PLA:PEG ratios

Targeting delivery system use natural drugs for tumor cells is an appealing platform help to reduce the side effects and enhance the therapeutic effects of the drug. In this study, we synthesized curcumin (Cur) loaded (D, L Poly lactic - Poly ethylenglycol) micelle (Cur/PLA-PEG) with the ratio of PLA/PEG of 3:1 2:1 1:1 1:2 and 1:3 (w/w) and another micelle modified by folate (Cur/PLA-PEG-Fol) for targeting cancer therapy. The PLA-PEG copolymer was synthesized by ring opening polymerization method. After loading onto the micelle, solubility of Cur increased from 0.38 to 0.73mgml(-1). The average size of prepared Cur/PLA-PEG micelles was from 60 to 69nm (corresponding to the ratio difference of PLA/PEG) and the drug encapsulating efficiency was from 48.8 to 91.3%. Compared with the Cur/PLA-PEG micelles, the size of Cur/PLA-PEG-Fol micelles were from 80 to 86nm and showed better in vitro cellular uptake and cytotoxicity towards HepG2 cells. The cytotoxicity of the NPs however depends much on the PEG component. The results demonstrated that Folate-modified micelles could serve as a potential nano carrier to improve solubility, anti-cancer activity of Cur and targeting ability of the system.

NIR-Remote Selected Activation Gene Expression in Living Cells by Upconverting Microrods

An NIR-controlled gene expression system based on upconverting rods (UCRs) is demonstrated. The UCRs can harvest the "biocompatible" NIR light and convert it into local UV light, resulting in cleavage of the photosensitive molecule (4-(hydroxymethyl)-3-nitrobenzoic acid, ONA) and on-demand release of gene carriers, thus realizing target gene expression at high spatial and temporal resolutions.

Folate-conjugated dually responsive micelles for targeted anticancer drug delivery

Folate-conjugated dual-responsive micelles were developed, sustained and sensitive drug release from the drug loaded micelles was observed. Folate-targeted micelles showed higher anticancer activity and enhanced cellar uptake than non-targeted ones.

Quaternary alloy quantum dots with widely tunable emission – a versatile system to fabricate dual-emission nanocomposites for bio-imaging

Highly luminescent Zn-I-III-VI-based QDs with widely composition-tuned PL emissions have been synthesized for multiscale biomedical optical imaging.

Nanoparticles of chitosan conjugated to organo-ruthenium complexes

The synthesis of nanoparticles of conjugates of caffeic acid-modified chitosan with ruthenium arene complexes is described.

CD147 monoclonal antibody mediated by chitosan nanoparticles loaded with α-hederin enhances antineoplastic activity and cellular uptake in liver cancer cells

An antibody that specifically interacts with an antigen could be applied to an active targeting delivery system. In this study, CD147 antibody was coupled with α-hed chitosan nanoparticles (α-Hed-CS-NPs). α-Hed-CS-CD147-NPs were round and spherical in shape, with an average particle size of 148.23 ± 1.75 nm. The half-maximum inhibiting concentration (IC50) of α-Hed-CS-CD147-NPs in human liver cancer cell lines HepG2 and SMMC-7721 was lower than that of free α-Hed and α-Hed-CS-NPs. α-Hed-induced cell death was mainly triggered by apoptosis. The increase in intracellular accumulation of α-Hed-CS-CD147-NPs was also related to CD147-mediated internalization through the Caveolae-dependent pathway and lysosomal escape. The higher targeting antitumor efficacy of α-Hed-CS-CD147-NPs than that α-Hed-CS-NPs was attributed to its stronger fluorescence intensity in the tumor site in nude mice.

Synergistic effect of cucurbitacin B in combination with curcumin via enhancing apoptosis induction and reversing multidrug resistance in human hepatoma cells

Cucurbitacin B is a plant-derived tetracyclic triterpenoid, which has been used for a variety of cancers, especially human hepatoma. Curcumin, isolated from a plant Curcuma longa also has found the anti-tumor property. In the present study, the synergistic effect of cucurbitacin B and curcumin was studied on BEL7402/5-Fu cells in vitro and BEL7402 tumor-bearing mice in vivo. The synergistic anticancer activity of these two compounds involves the two mechanisms. Firstly, curcumin synergistically enhanced the apoptosis of BEL7402/5-Fu cells induced by cucurbitacin B in the optimal mass ratio of 2:1 (cucurbitacin B:curcumin). The mechanism may result from the cell arresting in different phases of cell cycles and the apoptotic change of ultrastructure in BEL7402/5-Fu cells. Secondly, curcumin reversed the multidrug resistance (MDR) caused by cucurbitacin B in the optimized concentration of 67.9μM (25μg/ml). The mechanism was associated with the P-gp reduction, ΔΨm collapse and mitochondrial colocalization in BEL7402/5-Fu cells. The findings were consistent with the changes of the body weight and tumor volume, caspase3 activation and ATP down-regulation in vivo. In conclusion, cucurbitacin B in the combination with curcumin could serve as a novel, promising approach for human hepatoma.

Ultrasmall Chitosan-Genipin Nanocarriers Fabricated from Reverse Microemulsion Process for Tumor Photothermal Therapy in Mice

Nanocarriers play an important role in improving the photo- and thermal-stability of photosensitizers to gain better pharmacokinetics behavior in tumor photothermal therapy. Herein, PEGylated chitosan (CG-PEG; PEG: polyethylene glycol) nanoparticles with ultrasmall size (∼5 nm) were prepared through a water-in-oil reverse microemulsion method using genipin as a cross-linker. Particle size and zeta-potential can be tuned by varying the molar ratio between chitosan amino groups and genipin. CG-PEG-ICG (ICG: indocyanine green) nanoparticles were fabricated by adding ICG to CG-PEG aqueous solution through a self-assembly method via electrostatic interaction. The resultant CG-PEG-ICG nanoparticles exhibited improved photo- and thermal-stability, good biocompatibility, and low toxicity. When irradiated with a laser, the cells incubated with CG-PEG-ICG nanoparticles showed very low cell viability (15%), indicating the CG-PEG-ICG nanoparticles possess high in vitro photothermal toxicity. Moreover, the CG-PEG nanocarriers can significantly alter the biodistribution and prolong the retention time of ICG in the mice body after intravenous injection. In vivo photothermal study of tumors injected with CG-PEG-ICG nanoparticles containing ICG at a concentration greater than 100 μg·mL(-1) (100 μL) induced irreversible tissue damage. The growth of U87 tumors was dramatically inhibited by CG-PEG-ICG nanoparticles, demonstrating that the CG-PEG nanoparticles may act as potential ICG nanocarriers for effective in vivo tumor photothermal therapy.

Bioresorbable polyelectrolytes for smuggling drugs into cells

There is ample evidence that biodegradable polyelectrolyte nanocapsules are multifunctional vehicles which can smuggle drugs into cells, and release them upon endogenous activation. A large number of endogenous stimuli have already been tested in vitro, and in vivo research is escalating. Thus, the interest in the design of intelligent polyelectrolyte multilayer (PEM) drug delivery systems is clear. The need of the hour is a systematic translation of PEM-based drug delivery systems from the lab to clinical studies. Reviews on multifarious stimuli that can trigger the release of drugs from such systems already exist. This review summarizes the available literature, with emphasis on the recent progress in PEM-based drug delivery systems that are receptive in the presence of endogenous stimuli, including enzymes, glucose, glutathione, pH, and temperature, and addresses different active and passive drug targeting strategies. Insights into the current knowledge on the diversified endogenous approaches and methodological challenges may bring inspiration to resolve issues that currently bottleneck the successful implementation of polyelectrolytes into the catalog of third-generation drug delivery systems.

A bimodal MRI and NIR liposome nanoprobe for tumor targeted molecular imaging

The combination of complementary MRI and NIR imaging methods evolved to provide an even more powerful bioimaging tool.

Development of a folate-modified curcumin loaded micelle delivery system for cancer targeting

Targeted drug delivery system for tumor cells is an appealing platform on enhancing the therapeutic effects and reducing the side effects of the drug. In this study, we developed folate-modified curcumin (Cur) loaded micelles (Cur-FPPs) for cancer chemotherapy. The targeting material, Folate-PEG3000-PLA2000, was synthesized by the amide bond formation reaction. And the Cur loaded micelles were prepared by thin-film hydration method with mPEG2000-PLA2000 (Cur-PPs) or mPEG2000-PLA2000 and Folate-PEG3000-PLA2000 (Cur-FPPs) as carrier. A central composite design (CCD) was used to optimize the formulation, and the optimized Cur-FPPs was prepared with the weight ratio of Folate-PEG3000-PLA2000 and mPEG2000-PLA2000 at 1:9. The average size of the mixed micelles was 70nm, the encapsulating efficiency and drug-loading were 80.73±0.16% and 4.84±0.01%, respectively. Compared with the Cur propylene glycol solution, the in vitro release of Cur from Cur-FPPs showed a sustained manner. Furthermore, the in vitro cytotoxicity and cellular uptake of Cur-FPPs were significantly enhanced towards MCF-7 and HepG2 cells. The pharmacokinetic studies in rats indicated that a 3-fold increase in the half-life was achieved for Cur loaded micelle formulations relative to solubilized Cur. All the results demonstrated that folate-modified Cur micelles could serve as a potential nanocarrier to improve the solubility and anti-cancer activity of Cur.

Development of drug-loaded chitosan-vanillin nanoparticles and its cytotoxicity against HT-29 cells

Chitosan as a natural polysaccharide derived from chitin of arthropods like shrimp and crab, attracts much interest due to its inherent properties, especially for application in biomedical materials. Presently, biodegradable and biocompatible chitosan nanoparticles are attractive for drug delivery. However, some physicochemical characteristics of chitosan nanoparticles still need to be further improved in practice. In this work, chitosan nanoparticles were produced by crosslinking chitosan with 3-methoxy-4-hydroxybenzaldehyde (vanillin) through a Schiff reaction. Chitosan nanoparticles were 200-250 nm in diameter with smooth surface and were negatively charged with a zeta potential of - 17.4 mV in neutral solution. Efficient drug loading and drug encapsulation were achieved using 5-fluorouracil as a model of hydrophilic drug. Drug release from the nanoparticles was constant and controllable. The in vitro cytotoxicity against HT-29 cells and cellular uptake of the chitosan nanoparticles were evaluated by methyl thiazolyl tetrazolium method, confocal laser scanning microscope and flow cytometer, respectively. The results indicate that the chitosan nanoparticles crosslinked with vanillin are a promising vehicle for the delivery of anticancer drugs.

Preparation and characterization of galactosylated glycol chitosan micelles and its potential use for hepatoma-targeting delivery of doxorubicin

This study aimed to develop novel galactosylated cholesterol modified-glycol chitosan (Gal-CHGC) micelles for targeting delivery of doxorubicin (DOX) in live cancer cells. Three kinds of Gal-CHGC conjugates were synthesized and characterized. The mean particle size and critical aggregation concentration of these polymeric micelles increased with the increase of galactose substitution degree. The DOX-loaded micelles were prepared by an o/w method. The mean diameters of DOX-loaded galactosylated micelles were in the range of 387-497 nm. DOX released from drug-loaded micelles displayed a biphasic way. Cellular uptake studies demonstrated that DOX-loaded galactosylated micelles could enhance the uptake of DOX into HepG2 cells. Moreover, the cytotoxicity of DOX-loaded galactosylated micelles against HepG2 cells significantly improved in contrast with free DOX and DOX-loaded micelles without galactosylation. These results suggested that Gal-CHGC micelles could be a potential carrier for hepatoma-targeting drug delivery.

Therapeutic effect of the treatment for colorectal cancer with adenoviral vectors mediated estrogen receptor β gene therapy combined with thermotherapy

INTRODUCTION

Our preliminary study on repressing colorectal tumors by recombinant adenoviruses (Ads) delivering the human ERβ gene (Ad-ERβ) has achieved positive result.

METHODS

In this study, hydrophobic fluorescent dyes ICG-Der-01 was entrapped into the N-succinyl-N'-octyl chitosan (SOC) micelles to form the near infrared absorbing dyes SOC-ICG-Der-01 and SOC-ICG-Der-01 mediated near infrared laser (SOC-ICG-Der-01/NIR) thermotherapy was combined with Ad-ERβ gene therapy to regress colon cancer in vivo.

RESULTS

Firstly, the antitumor efficacies of SOC-ICG-Der-01/NIR thermotherapy were investigated on S180 ascites tumor-bearing mice. Results indicated that, the average tumor volume of SOC-ICG-Der-01/NIR group was the smallest among the three treatment groups. Then, thermotherapy with SOC-ICG-Der-01/NIR combined with Ad-ERβ gene therapy to treat HCT-116 colon cancer xenograft model was investigated. Further results demonstrated that, SOC-ICG-Der-01/NIR thermotherapy showed the significantly inhibitory efficiency compared with control group and Ad-ERβ enhanced the therapeutic effect of SOC-ICG-Der-01/NIR.

CONCLUSION

These findings demonstrated that combined administration of Ad-ERβ with SOC-ICG-Der-01/NIR thermotherapy represents a promising colon cancer therapeutic strategy.

Folate-mediated and doxorubicin-conjugated poly(ε-caprolactone)-g-chondroitin sulfate copolymers for enhanced intracellular drug delivery

The aim of this study was to conjugate an anticancer drug, doxorubicin (DOX) and a folate targeting moiety, folic acid (FA), to self-assembled polycaprolactone (PCL)-graft-chondroitin sulfate (CS) copolymers for enhanced chemotherapy.

Self-assembly-induced near-infrared fluorescent nanoprobes for effective tumor molecular imaging

Self-assembly-induced near-infrared fluorescent nanoprobes exhibiting spontaneous lattices were prepared and evaluated for in vitro and in vivo tumor molecular imaging.

Quaternary Zn-Ag-In-Se quantum dots for biomedical optical imaging of RGD-modified micelles

Exploring the synthesis of new biocompatible quantum dots (QDs) helps in overcoming the intrinsic toxicity of the existing QDs composed of highly toxic heavy metals (e.g., Cd, Hg, Pb, etc.) and is particularly interesting for the future practical application of QDs in biomedical imaging. Hence, in this report, a new one-pot approach to oil-soluble (highly toxic heavy metal-free) highly luminescent quaternary Zn-Ag-In-Se (ZAISe) QDs was designed. Their photoluminescence (PL) emission could be systematically tuned from 660 to 800 nm by controlling the Ag/Zn feed ratio, and their highest PL quantum yield is close to 50% after detailed optimization. Next, by using biodegradable RGD peptide (arginine-glycine-aspartic acid)-modified N-succinyl-N'-octyl-chitosan (RGD-SOC) micelles as a water transfer agent, the versatility of these quaternary ZAISe QDs for multiscale bioimaging of micelles (namely, in vitro and in vivo evaluating the tumor targeting of drug carriers) was further explored, as a promising alternative for Cd- and Pb-based QDs.